How the 2008 stock market crash and seasons affect total and cardiac deaths in Los Angeles County.

PubMed

Schwartz, Bryan Glen; Pezzullo, John Christopher; McDonald, Scott Andrew; Poole, William Kenneth; Kloner, Robert Alan

2012-05-15

Various stressors trigger cardiac death. The objective was to investigate a possible relation between a stock market crash and cardiac death in a large population within the United States. We obtained daily stock market data (Dow Jones Industrial Average Index), death certificate data for daily deaths in Los Angeles County (LA), and annual LA population estimates for 2005 through 2008. The 4 years death rate curves (2005 through 2008) were averaged into a single curve to illustrate annual trends. Data were "deseasonalized" by subtracting from the daily observed value the average value for that day of year. There was marked seasonal variation in total and cardiac death rates. Even in the mild LA climate, death rates were higher in winter versus summer including total death (+17%), circulatory death (+24%), coronary heart disease death (+28%), and myocardial infarction death (+38%) rates (p <0.0001 for each). Absolute coronary heart disease death rates have decreased since 1985. After accounting for seasonal variation, the large stock market crash in October 2008 did not affect death rates in LA. Death rates remained at or below seasonal averages during the stock market crash. In conclusion, after correcting for seasonal variation, the stock market crash in October 2008 was not associated with an increase in total or cardiac death in LA. Annual coronary heart disease death rates continue to decrease. However, seasonal variation (specifically winter) remains a trigger for death and coronary heart disease death even in LA where winters are mild. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of IV Acetaminophen on Core Body Temperature and Hemodynamic Responses in Febrile Critically Ill Adults: A Randomized Controlled Trial.

PubMed

Schell-Chaple, Hildy M; Liu, Kathleen D; Matthay, Michael A; Sessler, Daniel I; Puntillo, Kathleen A

2017-07-01

To determine the effects of IV acetaminophen on core body temperature, blood pressure, and heart rate in febrile critically ill patients. Randomized, double-blind, placebo-controlled clinical trial. Three adult ICUs at a large, urban, academic medical center. Forty critically ill adults with fever (core temperature, ≥ 38.3°C). An infusion of acetaminophen 1 g or saline placebo over 15 minutes. Core temperature and vital signs were measured at baseline and at 5-15-minute intervals for 4 hours after infusion of study drug. The primary outcome was time-weighted average core temperature adjusted for baseline temperature. Secondary outcomes included adjusted time-weighted average heart rate, blood pressure, and respiratory rate, along with changes-over-time for each. Baseline patient characteristics were similar in those given acetaminophen and placebo. Patients given acetaminophen had an adjusted time-weighted average temperature that was 0.47°C less than those given placebo (95% CI, -0.76 to -0.18; p = 0.002). The acetaminophen group had significantly lower adjusted time-weighted average systolic blood pressure (-17 mm Hg; 95% CI, -25 to -8; p < 0.001), mean arterial pressure (-7 mm Hg; 95% CI, -12 to -1; p = 0.02), and heart rate (-6 beats/min; 95% CI, -10 to -1; p = 0.03). Changes-over-time temperature, blood pressure, and heart rate outcomes were also significantly lower at 2 hours, but not at 4 hours. Among febrile critically ill adults, treatment with acetaminophen decreased temperature, blood pressure, and heart rate. IV acetaminophen thus produces modest fever reduction in critical care patients, along with clinically important reductions in blood pressure.

Quantifying the Physiological Stress Response to Simulated Maritime Pilotage Tasks

PubMed Central

Main, Luana C.; Wolkow, Alexander; Chambers, Timothy P.

2017-01-01

Objective: The aim of this study was to quantify the stress associated with performing maritime pilotage tasks in a high-fidelity simulator. Methods: Eight trainee and 13 maritime pilots completed two simulated pilotage tasks of varying complexity. Salivary cortisol samples were collected pre- and post-simulation for both trials. Heart rate was measured continuously throughout the study. Results: Significant changes in salivary cortisol (P = 0.000, η2 = 0.139), average (P = 0.006, η2 = 0.087), and peak heart rate (P = 0.013, η2 = 0.077) from pre- to postsimulation were found. Varying task complexity did partially influence stress response; average (P = 0.016, η2 = 0.026) and peak heart rate (P = 0.034, η2 = 0.020) were higher in the experimental condition. Trainees also recorded higher average (P = 0.000, η2 = 0.054) and peak heart rates (P = 0.027, η2 = 0.022). Conclusion: Performing simulated pilotage tasks evoked a measurable stress response in both trainee and expert maritime pilots. PMID:28922309

Heart Rate Effects of Intraosseous Injections Using Slow and Fast Rates of Anesthetic Solution Deposition

PubMed Central

Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa

2008-01-01

The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe. PMID:18327970

Heart rate effects of intraosseous injections using slow and fast rates of anesthetic solution deposition.

PubMed

Susi, Louis; Reader, Al; Nusstein, John; Beck, Mike; Weaver, Joel; Drum, Melissa

2008-01-01

The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow injection); a conventional syringe injection at a deposition rate of 4 minutes and 45 seconds (slow injection), in 3 separate appointments spaced at least 3 weeks apart. A pulse oximeter measured heart rate (pulse). The results demonstrated the mean maximum heart rate was statistically higher with the fast intraosseous injection (average 21 to 28 beats/min increase) than either of the 2 slow intraosseous injections (average 10 to 12 beats/min increase). There was no statistically significant difference between the 2 slow injections. We concluded that an intraosseous injection of 1.4 mL of 2% lidocaine with 1 : 100,000 epinephrine with the Wand at a 45-second rate of anesthetic deposition resulted in a significantly higher heart rate when compared with a 4-minute and 45-second anesthetic solution deposition using either the Wand or traditional syringe.

Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

1986-01-01

Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

Cardiovascular responses to noise: Effects of self-estimated sensitivity to noise, sex, and time of the day

NASA Astrophysics Data System (ADS)

di Nisi, J.; Muzet, A.; Weber, L. D.

1987-04-01

Eighty subjects of both sexes were selected according to their self-estimated high or low sensitivity to noise. Noise exposure took place during a mental task ("sound" condition) or during a video film illustrating the noises ("sound and video" condition). The experiments were conducted between 0900 and 1100 hours or between 1500 and 1700 hours. Heart rate response and finger pulse response amplitudes were averaged separately for "sound" and "sound and video" conditions. In the "sound" condition, the average amplitude of the heart rate response differed significantly between noise-sensitivity groups: the low sensitivity group showed a lower average amplitude of heart rate response than the high sensitivity group. A significant interaction between sex and time of the day (morning or afternoon) was observed in both "sound" and "sound and video" conditions. In the "sound" condition, the percentage of noises inducing a finger pulse response appeared higher in female than in male subjects.

Heart rate estimation from FBG sensors using cepstrum analysis and sensor fusion.

PubMed

Zhu, Yongwei; Fook, Victor Foo Siang; Jianzhong, Emily Hao; Maniyeri, Jayachandran; Guan, Cuntai; Zhang, Haihong; Jiliang, Eugene Phua; Biswas, Jit

2014-01-01

This paper presents a method of estimating heart rate from arrays of fiber Bragg grating (FBG) sensors embedded in a mat. A cepstral domain signal analysis technique is proposed to characterize Ballistocardiogram (BCG) signals. With this technique, the average heart beat intervals can be estimated by detecting the dominant peaks in the cepstrum, and the signals of multiple sensors can be fused together to obtain higher signal to noise ratio than each individual sensor. Experiments were conducted with 10 human subjects lying on 2 different postures on a bed. The estimated heart rate from BCG was compared with heart rate ground truth from ECG, and the mean error of estimation obtained is below 1 beat per minute (BPM). The results show that the proposed fusion method can achieve promising heart rate measurement accuracy and robustness against various sensor contact conditions.

Behavioral correlates of heart rates of free-living Greater White-fronted Geese

USGS Publications Warehouse

Ely, Craig R.; Ward, D.H.; Bollinger, K.S.

1999-01-01

We simultaneously monitored the heart rate and behavior of nine free-living Greater White-fronted Geese (Anser albifrons) on their wintering grounds in northern California. Heart rates of wild geese were monitored via abdominally-implanted radio transmitters with electrodes that received electrical impulses of the heart and emitted a radio signal with each ventricular contraction. Post-operative birds appeared to behave normally, readily rejoining flocks and flying up to 15 km daily from night-time roost sites to feed in surrounding agricultural fields. Heart rates varied significantly among individuals and among behaviors, and ranged from less than 100 beats per minute (BPM) during resting, to over 400 BPM during flight. Heart rates varied from 80 to 140 BPM during non-strenuous activities such as walking, feeding, and maintenance activities, to about 180 BPM when birds became alert, and over 400 BPM when birds were startled, even if they did not take flight. Postflight heart rate recovery time averaged < 10 sec. During agonistic encounters, heart rate exceeded 400 BPM; heart rates during social interactions were not predictable solely from postures, as heart rates were context-dependent, and were highest in initial encounters among individuals. Instantaneous measures of physiological parameters, such as heart rate, are often better indicators of the degree of response to external stimuli than visual observations and can be used to improve estimates of energy expenditure based solely on activity data.

Fitbit Charge HR Wireless Heart Rate Monitor: Validation Study Conducted Under Free-Living Conditions.

PubMed

Gorny, Alexander Wilhelm; Liew, Seaw Jia; Tan, Chuen Seng; Müller-Riemenschneider, Falk

2017-10-20

Many modern smart watches and activity trackers feature an optical sensor that estimates the wearer's heart rate. Recent studies have evaluated the performance of these consumer devices in the laboratory. The objective of our study was to examine the accuracy and sensitivity of a common wrist-worn tracker device in measuring heart rates and detecting 1-min bouts of moderate to vigorous physical activity (MVPA) under free-living conditions. Ten healthy volunteers were recruited from a large university in Singapore to participate in a limited field test, followed by a month of continuous data collection. During the field test, each participant would wear one Fitbit Charge HR activity tracker and one Polar H6 heart rate monitor. Fitbit measures were accessed at 1-min intervals, while Polar readings were available for 10-s intervals. We derived intraclass correlation coefficients (ICCs) for individual participants comparing heart rate estimates. We applied Centers for Disease Control and Prevention heart rate zone cut-offs to ascertain the sensitivity and specificity of Fitbit in identifying 1-min epochs falling into MVPA heart rate zone. We collected paired heart rate data for 2509 1-min epochs in 10 individuals under free-living conditions of 3 to 6 hours. The overall ICC comparing 1-min Fitbit measures with average 10-s Polar H6 measures for the same epoch was .83 (95% CI .63-.91). On average, the Fitbit tracker underestimated heart rate measures by -5.96 bpm (standard error, SE=0.18). At the low intensity heart rate zone, the underestimate was smaller at -4.22 bpm (SE=0.15). This underestimate grew to -16.2 bpm (SE=0.74) in the MVPA heart rate zone. Fitbit devices detected 52.9% (192/363) of MVPA heart rate zone epochs correctly. Positive and negative predictive values were 86.1% (192/223) and 92.52% (2115/2286), respectively. During subsequent 1 month of continuous data collection (270 person-days), only 3.9% of 1-min epochs could be categorized as MVPA according to heart rate zones. This measure was affected by decreasing wear time and adherence over the period of follow-up. Under free-living conditions, Fitbit trackers are affected by significant systematic errors. Improvements in tracker accuracy and sensitivity when measuring MVPA are required before they can be considered for use in the context of exercise prescription to promote better health. ©Alexander Wilhelm Gorny, Seaw Jia Liew, Chuen Seng Tan, Falk Müller-Riemenschneider. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 20.10.2017.

The effects of body thermal state on manual performance.

DOT National Transportation Integrated Search

1968-05-01

Thirty-six young men were exposed for 2 hours to environmental temperatures of 10, 26.7, or 46C. Measurements of rectal and skin temperature, heart rate and respiratory rate were made, and average skin and average body temperatures were calculated. M...

[Mortality rate of acute heart attack in Zalaegerszeg micro-region. Results of the first Hungarian 24-hour acute ST-elevation myocardial infarction intervention care unit].

PubMed

Lupkovics, Géza; Motyovszki, Akos; Németh, Zoltán; Takács, István; Kenéz, András; Burkali, Bernadett; Menyhárt, Ildikó

2010-04-04

Morbidity and mortality rates of acute heart attack emphasize the significance of this patient group worldwide. The prompt and exact diagnosis and the timing of adequate therapy is crucial for this patients. Modern supply of acute heart attack includes invasive cardiology intervention, primer percutaneous coronary intervention. In year 1999, American and European recommendations suggested primer percutaneous coronary intervention only as an alternative possibility instead of thrombolysis, or in case of cardiogenic shock. 24 hour intervention unit for patients with acute heart attack was first organized in Hungary in Zala County Hospital's Cardiology Department, in year 1998. Our present study confirms, that since the intervention treatment has been introduced, average mortality rate has been reduced considerably in our area comparing to the national average. Mortality rates in West Transdanubian region and in Zalaegerszeg's micro-region were studied and compared for the period between 1997-2004, according to the data of National Public Health and Medical Officer Service. These data were then compared with the national average mortality data of Hungarian Central Statistical Office. With the help of our own computerized database we examined this period and compared the number of the completed invasive interventions to the mortality statistics. In the first full year, in 1998, we completed 82 primer and 283 elective PCIs; these number increased to 318 and 1265 by year 2005. At the same time, significant decrease of acute infarction related mortality was detectable among men of the Zalaegerszeg micro-region, comparing to the national average (p<0.001). The first Hungarian 24 hour acute heart attack intervention care improved the area's mortality statistics significantly, comparing to the national average. The skilled work of the experienced team means an important advantage to the patients in Zalaegerszeg micro-region.

Minimal changes in heart rate of incubating American Oystercatchers (Haematopus palliatus) in response to human activity

USGS Publications Warehouse

Borneman, Tracy E.; Rose, Eli T.; Simons, Theodore R.

2014-01-01

An organism's heart rate is commonly used as an indicator of physiological stress due to environmental stimuli. We used heart rate to monitor the physiological response of American Oystercatchers (Haematopus palliatus) to human activity in their nesting environment. We placed artificial eggs with embedded microphones in 42 oystercatcher nests to record the heart rate of incubating oystercatchers continuously for up to 27 days. We used continuous video and audio recordings collected simultaneously at the nests to relate physiological response of birds (heart rate) to various types of human activity. We observed military and civilian aircraft, off-road vehicles, and pedestrians around nests. With the exception of high-speed, low-altitude military overflights, we found little evidence that oystercatcher heart rates were influenced by most types of human activity. The low-altitude flights were the only human activity to significantly increase average heart rates of incubating oystercatchers (12% above baseline). Although statistically significant, we do not consider the increase in heart rate during high-speed, low-altitude military overflights to be of biological significance. This noninvasive technique may be appropriate for other studies of stress in nesting birds.

State-level minimum wage and heart disease death rates in the United States, 1980-2015: A novel application of marginal structural modeling.

PubMed

Van Dyke, Miriam E; Komro, Kelli A; Shah, Monica P; Livingston, Melvin D; Kramer, Michael R

2018-07-01

Despite substantial declines since the 1960's, heart disease remains the leading cause of death in the United States (US) and geographic disparities in heart disease mortality have grown. State-level socioeconomic factors might be important contributors to geographic differences in heart disease mortality. This study examined the association between state-level minimum wage increases above the federal minimum wage and heart disease death rates from 1980 to 2015 among 'working age' individuals aged 35-64 years in the US. Annual, inflation-adjusted state and federal minimum wage data were extracted from legal databases and annual state-level heart disease death rates were obtained from CDC Wonder. Although most minimum wage and health studies to date use conventional regression models, we employed marginal structural models to account for possible time-varying confounding. Quasi-experimental, marginal structural models accounting for state, year, and state × year fixed effects estimated the association between increases in the state-level minimum wage above the federal minimum wage and heart disease death rates. In models of 'working age' adults (35-64 years old), a $1 increase in the state-level minimum wage above the federal minimum wage was on average associated with ~6 fewer heart disease deaths per 100,000 (95% CI: -10.4, -1.99), or a state-level heart disease death rate that was 3.5% lower per year. In contrast, for older adults (65+ years old) a $1 increase was on average associated with a 1.1% lower state-level heart disease death rate per year (b = -28.9 per 100,000, 95% CI: -71.1, 13.3). State-level economic policies are important targets for population health research. Copyright © 2018 Elsevier Inc. All rights reserved.

Monitoring nocturnal heart rate with bed sensor.

PubMed

Migliorini, M; Kortelainen, J M; Pärkkä, J; Tenhunen, M; Himanen, S L; Bianchi, A M

2014-01-01

This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". The aim of this study is to assess the reliability of the estimated Nocturnal Heart Rate (HR), recorded through a bed sensor, compared with the one obtained from standard electrocardiography (ECG). Twenty-eight sleep deprived patients were recorded for one night each through matrix of piezoelectric sensors, integrated into the mattress, through polysomnography (PSG) simultaneously. The two recording methods have been compared in terms of signal quality and differences in heart beat detection. On average, coverage of 92.7% of the total sleep time was obtained for the bed sensor, testifying the good quality of the recordings. The average beat-to-beat error of the inter-beat intervals was 1.06%. These results suggest a good overall signal quality, however, considering fast heart rates (HR > 100 bpm), performances were worse: in fact, the sensitivity in the heart beat detection was 28.4% while the false positive rate was 3.8% which means that a large amount of fast beats were not detected. The accuracy of the measurements made using the bed sensor has less than 10% of failure rate especially in periods with HR lower than 70 bpm. For fast heart beats the uncertainty increases. This can be explained by the change in morphology of the bed sensor signal in correspondence of a higher HR.

The effect of deep-tissue massage therapy on blood pressure and heart rate.

PubMed

Kaye, Alan David; Kaye, Aaron J; Swinford, Jan; Baluch, Amir; Bawcom, Brad A; Lambert, Thomas J; Hoover, Jason M

2008-03-01

In the present study, we describe the effects of deep tissue massage on systolic, diastolic, and mean arterial blood pressure. The study involved 263 volunteers (12% males and 88% females), with an average age of 48.5. Overall muscle spasm/muscle strain was described as either moderate or severe for each patient. Baseline blood pressure and heart rate were measured via an automatic blood pressure cuff. Twenty-one (21) different soothing CDs played in the background as the deep tissue massage was performed over the course of the study. The massages were between 45 and 60 minutes in duration. The data were analyzed using analysis of variance with post-hoc Scheffe's F-test. Results of the present study demonstrated an average systolic pressure reduction of 10.4 mm Hg (p<0.06), a diastolic pressure reduction of 5.3 mm Hg (p<0.04), a mean arterial pressure reduction of 7.0 mm Hg (p<0.47), and an average heart rate reduction of 10.8 beats per minute (p<0.0003), respectively. Additional scientific research in this area is warranted.

Non-contact Real-time heart rate measurements based on high speed circuit technology research

NASA Astrophysics Data System (ADS)

Wu, Jizhe; Liu, Xiaohua; Kong, Lingqin; Shi, Cong; Liu, Ming; Hui, Mei; Dong, Liquan; Zhao, Yuejin

2015-08-01

In recent years, morbidity and mortality of the cardiovascular or cerebrovascular disease, which threaten human health greatly, increased year by year. Heart rate is an important index of these diseases. To address this status, the paper puts forward a kind of simple structure, easy operation, suitable for large populations of daily monitoring non-contact heart rate measurement. In the method we use imaging equipment video sensitive areas. The changes of light intensity reflected through the image grayscale average. The light change is caused by changes in blood volume. We video the people face which include the sensitive areas (ROI), and use high-speed processing circuit to save the video as AVI format into memory. After processing the whole video of a period of time, we draw curve of each color channel with frame number as horizontal axis. Then get heart rate from the curve. We use independent component analysis (ICA) to restrain noise of sports interference, realized the accurate extraction of heart rate signal under the motion state. We design an algorithm, based on high-speed processing circuit, for face recognition and tracking to automatically get face region. We do grayscale average processing to the recognized image, get RGB three grayscale curves, and extract a clearer pulse wave curves through independent component analysis, and then we get the heart rate under the motion state. At last, by means of compare our system with Fingertip Pulse Oximeter, result show the system can realize a more accurate measurement, the error is less than 3 pats per minute.

Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years - United States, 1968-2015.

PubMed

Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele

2018-03-30

Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. 1968-2015. The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968-2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968-2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases occurring during the 1970s and 1980s followed by small but steady increases until approximately 2005. Since 2005, modest decreases have occurred in the black-white ratio of heart disease death rates at the national level. The majority of states had increases in black-white mortality ratios from 1968 to 2015. The number of states with black-white mortality ratios >1 increased from 16 (40%) to 27 (67.5%). Although heart disease death rates decreased both for blacks and whites from 1968 to 2015, substantial differences in decreases were found by race and state. At the national level and in most states, blacks experienced smaller decreases in heart disease death rates than whites for the majority of the period. Overall, the black-white disparity in heart disease death rates increased from 1968 to 2005, with a modest decrease from 2005 to 2015. Since 1968, substantial increases have occurred in black-white disparities of heart disease death rates in the United States at the national level and in many states. These increases appear to be due to faster decreases in heart disease death rates for whites than blacks, particularly from the late 1970s until the mid-2000s. Despite modest decreases in black-white disparities at the national level since 2005, in 2015, heart disease death rates were 21% higher among blacks than among whites. This study demonstrates the use of NVSS data to conduct surveillance of heart disease death rates by race and of black-white disparities in heart disease death rates. Continued surveillance of temporal trends in heart disease death rates by race can provide valuable information to policy makers and public health practitioners working to reduce heart disease death rates both for blacks and whites and disparities between blacks and whites.

Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years — United States, 1968–2015

PubMed Central

Van Dyke, Miriam; Greer, Sophia; Odom, Erika; Schieb, Linda; Vaughan, Adam; Kramer, Michael; Casper, Michele

2018-01-01

Problem/Condition Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state. Period Covered 1968–2015. Description of System The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968–2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968–2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses. Results From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases occurring during the 1970s and 1980s followed by small but steady increases until approximately 2005. Since 2005, modest decreases have occurred in the black-white ratio of heart disease death rates at the national level. The majority of states had increases in black-white mortality ratios from 1968 to 2015. The number of states with black-white mortality ratios >1 increased from 16 (40%) to 27 (67.5%). Interpretation Although heart disease death rates decreased both for blacks and whites from 1968 to 2015, substantial differences in decreases were found by race and state. At the national level and in most states, blacks experienced smaller decreases in heart disease death rates than whites for the majority of the period. Overall, the black-white disparity in heart disease death rates increased from 1968 to 2005, with a modest decrease from 2005 to 2015. Public Health Action Since 1968, substantial increases have occurred in black-white disparities of heart disease death rates in the United States at the national level and in many states. These increases appear to be due to faster decreases in heart disease death rates for whites than blacks, particularly from the late 1970s until the mid-2000s. Despite modest decreases in black-white disparities at the national level since 2005, in 2015, heart disease death rates were 21% higher among blacks than among whites. This study demonstrates the use of NVSS data to conduct surveillance of heart disease death rates by race and of black-white disparities in heart disease death rates. Continued surveillance of temporal trends in heart disease death rates by race can provide valuable information to policy makers and public health practitioners working to reduce heart disease death rates both for blacks and whites and disparities between blacks and whites. PMID:29596406

Heart rate and respiratory rhythm dynamics on ascent to high altitude.

PubMed Central

Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

1995-01-01

OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress. PMID:7488453

Heart rate and respiratory rhythm dynamics on ascent to high altitude

NASA Technical Reports Server (NTRS)

Lipsitz, L. A.; Hashimoto, F.; Lubowsky, L. P.; Mietus, J.; Moody, G. B.; Appenzeller, O.; Goldberger, A. L.

1995-01-01

OBJECTIVE--To investigate the alterations in autonomic control of heart rate at high altitude and to test the hypothesis that hypoxaemic stress during exposure to high altitude induces non-linear, periodic heart rate oscillations, similar to those seen in heart failure and the sleep apnoea syndrome. SUBJECTS--11 healthy subjects aged 24-64. MAIN OUTCOME MEASURES--24 hour ambulatory electrocardiogram records obtained at baseline (1524 m) and at 4700 m. Simultaneous heart rate and respiratory dynamics during 2.5 hours of sleep by fast Fourier transform analysis of beat to beat heart rate and of an electrocardiographically derived respiration signal. RESULTS--All subjects had resting hypoxaemia at high altitude, with an average oxyhaemoglobin saturation of 81% (5%). There was no significant change in mean heart rate, but low frequency (0.01-0.05 Hz) spectral power was increased (P < 0.01) at high altitude. Time series analysis showed a complex range of non-linear sinus rhythm dynamics. Striking low frequency (0.04-0.06 Hz) heart rate oscillations were observed during sleep in eight subjects at high altitude. Analysis of the electrocardiographically derived respiration signal indicated that these heart rate oscillations correlated with low frequency respiratory oscillations. CONCLUSIONS--These data suggest (a) that increased low frequency power during high altitude exposure is not simply attributable to increased sympathetic modulation of heart rate, but relates to distinctive cardiopulmonary oscillations at approximately 0.05 Hz and (b) that the emergence of periodic heart rate oscillations at high altitude is consistent with an unstable cardiopulmonary control system that may develop on acute exposure to hypoxaemic stress.

Comparison of Cerebral Oximeter and Pulse Oximeter Values in the First 72 Hours in Premature, Asphyctic and Healthy Newborns.

PubMed

Kaya, A; Okur, M; Sal, E; Peker, E; Köstü, M; Tuncer, O; Kırımi, E

2014-12-01

The monitoring of oxygenation is essential for providing patient safety and optimal results. We aimed to determine brain oxygen saturation values in healthy, asphyctic and premature newborns and to compare cerebral oximeter and pulse oximeter values in the first 72 hours of life in neonatal intensive care units. This study was conducted at the neonatal intensive care unit (NICU) of Van Yüzüncü Yil University Research and Administration Hospital. Seventy-five neonatal infants were included in the study (28 asphyxia, 24 premature and 23 mature healthy infants for control group). All infants were studied within the first 72 hours of life. We used a Somanetics 5100C cerebral oximeter (INVOS cerebral/somatic oximeter, Troy, MI, USA). The oxygen saturation information was collected by a Nellcor N-560 pulse oximeter (Nellcor-Puriton Bennet Inc, Pleasanton, CA, USA). In the asphyxia group, the cerebral oximeter average was 76.85 ± 14.1, the pulse oximeter average was 91.86 ± 5.9 and the heart rate average was 139.91 ± 22.3. Among the premature group, the cerebral oximeter average was 79.08 ± 9.04, the pulse oximeter average was 92.01 ± 5.3 and the heart rate average was 135.35 ± 17.03. In the control group, the cerebral oximeter average was 77.56 ± 7.6, the pulse oximeter average was 92.82 ± 3.8 and the heart rate average was 127.04 ± 19.7. Cerebral oximeter is a promising modality in bedside monitoring in neonatal intensive care units. It is complementary to pulse oximeter. It may be used routinely in neonatal intensive care units.

Comparison of Cerebral Oximeter and Pulse Oximeter Values in the First 72 Hours in Premature, Asphyctic and Healthy Newborns

PubMed Central

Kaya, A; Okur, M; Sal, E; Peker, E; Köstü, M; Tuncer, O; Kirimi, E

2014-01-01

ABSTRACT Aim: The monitoring of oxygenation is essential for providing patient safety and optimal results. We aimed to determine brain oxygen saturation values in healthy, asphyctic and premature newborns and to compare cerebral oximeter and pulse oximeter values in the first 72 hours of life in neonatal intensive care units. Methods: This study was conducted at the neonatal intensive care unit (NICU) of Van Yüzüncü Yil University Research and Administration Hospital. Seventy-five neonatal infants were included in the study (28 asphyxia, 24 premature and 23 mature healthy infants for control group). All infants were studied within the first 72 hours of life. We used a Somanetics 5100C cerebral oximeter (INVOS cerebral/somatic oximeter, Troy, MI, USA). The oxygen saturation information was collected by a Nellcor N-560 pulse oximeter (Nellcor-Puriton Bennet Inc, Pleasanton, CA, USA). Results: In the asphyxia group, the cerebral oximeter average was 76.85 ± 14.1, the pulse oximeter average was 91.86 ± 5.9 and the heart rate average was 139.91 ± 22.3. Among the premature group, the cerebral oximeter average was 79.08 ± 9.04, the pulse oximeter average was 92.01 ± 5.3 and the heart rate average was 135.35 ± 17.03. In the control group, the cerebral oximeter average was 77.56 ± 7.6, the pulse oximeter average was 92.82 ± 3.8 and the heart rate average was 127.04 ± 19.7. Conclusion: Cerebral oximeter is a promising modality in bedside monitoring in neonatal intensive care units. It is complementary to pulse oximeter. It may be used routinely in neonatal intensive care units. PMID:25867556

Autonomic changes after treatment of agoraphobia with panic attacks.

PubMed

Roth, W T; Telch, M J; Taylor, C B; Agras, W S

1988-04-01

Twenty-three patients meeting DSM-III criteria for agoraphobia with panic attacks and 14 age-, race-, and sex-matched nonanxious controls were tested in the laboratory and on a test walk in a shopping mall. The patients were tested before and after about 15 weeks of treatment with placebo and exposure therapy, imipramine and exposure therapy, or imipramine and initial antiexposure instructions. Controls were tested twice at a similar interval, but without any treatment. On test day 1, patients compared to controls showed higher average heart rate and skin conductance levels and greater numbers of skin conductance fluctuations in the laboratory, and higher heart rates before and during the test walk. Between pretreatment and posttreatment tests, clinical ratings improved and skin conductance levels decreased in all treatment groups. Heart rate levels in the laboratory, on the other hand, decreased in patients on placebo and rose in patients on imipramine. Thus, imipramine compromises the usefulness of heart rate as a measure of emotional arousal. Higher pretreatment heart rates predicted greater clinical improvement.

Abnormal cardiovascular responses induced by localized high power microwave exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, S.-T; Brown, D.O.; Johnson, C.E.

1992-05-01

A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz and 16 Hz pulsemodulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in themore » neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power but not to the lower average power microwaves. Depression of pulse pressure, an indication of a decrease in stroke volume, and increased or decreased heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals.« less

T wave alternans during exercise and atrial pacing in humans

NASA Technical Reports Server (NTRS)

Hohnloser, S. H.; Klingenheben, T.; Zabel, M.; Li, Y. G.; Albrecht, P.; Cohen, R. J.

1997-01-01

INTRODUCTION: Evidence is accumulating that microvolt T wave alternans (TWA) is a marker of increased risk for ventricular tachyarrhythmias. Initially, atrial pacing was used to elevate heart rate and elicit TWA. More recently, a noninvasive approach has been developed that elevates heart rate using exercise. METHODS AND RESULTS: In 30 consecutive patients with a history of ventricular tachyarrhythmias, the spectral method was used to detect TWA during both atrial pacing and submaximal exercise testing. The concordance rate for the presence or absence of TWA using the two measurement methods was 84%. There was a patient-specific heart rate threshold for the detection of TWA that averaged 100 +/- 14 beats/min during exercise compared with 97 +/- 9 beats/min during right atrial pacing (P = NS). Beyond this threshold, there was a significant and comparable increase in level of TWA with decreasing pacing cycle length and increasing exercise heart rates. CONCLUSIONS: The present study is the first to demonstrate that microvolt TWA can be assessed reliably and noninvasively during exercise stress. There is a patient-specific heart rate threshold beyond which TWA continues to increase with increasing heart rates. Heart rate thresholds for the onset of TWA measured during atrial pacing and exercise stress were comparable, indicating that heart rate alone appears to be the main factor of determining the onset of TWA during submaximal exercise stress.

Physical capacity of rescue personnel in the mining industry

PubMed Central

Stewart, Ian B; McDonald, Michael D; Hunt, Andrew P; Parker, Tony W

2008-01-01

Background The mining industry has one of the highest occupational rates of serious injury and fatality. Mine staff involved with rescue operations are often required to respond to physically challenging situations. This paper describes the physical attributes of mining rescue personnel. Methods 91 rescue personnel (34 ± 8.6 yrs, 1.79 ± 0.07 m, 90 ± 15.0 kg) participating in the Queensland Mines Rescue Challenge completed a series of health-related and rescue-related fitness tasks. Health-related tasks comprised measurements of aerobic capacity (VO2max), abdominal endurance, abdominal strength, flexibility, lower back strength, leg strength, elbow flexion strength, shoulder strength, lower back endurance, and leg endurance. Rescue-related tasks comprised an incremental carry (IC), coal shovel (CS), and a hose drag (HD), completed in this order. Results Cardiovascular (VO2max) and muscular endurance was average or below average compared with the general population. Isometric strength did not decline with age. The rescue-related tasks were all extremely demanding with heart rate responses averaging greater than 88% of age predicted maximal heart rates. Heart rate recovery responses were more discriminating than heart rates recorded during the tasks, indicating the hose drag as the most physically demanding of the tasks. Conclusion Relying on actual rescues or mining related work to provide adequate training is generally insufficient to maintain, let alone increase, physical fitness. It is therefore recommended that standards of required physical fitness be developed and mines rescue personnel undergo regularly training (and assessment) in order to maintain these standards. PMID:18847510

Can heart rate predict blood pressure response to anti-hypertensive drug therapy?

PubMed

Owens, P E; Lyons, S; O'Brien, E

1998-04-01

The use of heart rate in clinical practice is limited by its variability under measurement situations. The mean heart rate on ambulatory monitoring provides a more robust statistic for clinical use. We examined the relationship between mean heart rate on initial referral ambulatory blood pressure monitoring (ABPM) to the BP-lowering efficacy of the four main groups of anti-hypertensive medications, in a referral hypertensive population. Patients were retrospectively identified by review of the BP database, and data collected from the initial referral BP monitor off medication, and the subsequent ABPM after treatment with either beta-blockers, diuretics, calcium antagonists or angiotensin-converting enzyme (ACE) inhibitors. The change in mean arterial BP from the initial to the subsequent ABPM (ie, as a result of treatment) was correlated with the mean heart rate on the initial ABPM. A moderate association was found for initial daytime heart rate and BP response to beta-blockers (r = 0.24, P = 0.02), and ACE inhibitors (r = 0.14, P = 0.05). No such association was found for calcium antagonists or diuretics. When the groups were divided into those with a mean daytime heart rate <75 and > or =75 beats per min, BP reduction from beta-blocker and ACE inhibitor therapy was significantly greater in those patients with a higher daytime heart rate. We conclude that average daytime heart rate on pre-treatment ABPM can be useful as a predictor of BP response to beta-blockade or ACE inhibition.

Heart Rate Dynamics During A Treadmill Cardiopulmonary Exercise Test in Optimized Beta-Blocked Heart Failure Patients

PubMed Central

Carvalho, Vitor Oliveira; Guimarães, Guilherme Veiga; Ciolac, Emmanuel Gomes; Bocchi, Edimar Alcides

2008-01-01

BACKGROUND Calculating the maximum heart rate for age is one method to characterize the maximum effort of an individual. Although this method is commonly used, little is known about heart rate dynamics in optimized beta-blocked heart failure patients. AIM The aim of this study was to evaluate heart rate dynamics (basal, peak and % heart rate increase) in optimized beta-blocked heart failure patients compared to sedentary, normal individuals (controls) during a treadmill cardiopulmonary exercise test. METHODS Twenty-five heart failure patients (49±11 years, 76% male), with an average LVEF of 30±7%, and fourteen controls were included in the study. Patients with atrial fibrillation, a pacemaker or noncardiovascular functional limitations or whose drug therapy was not optimized were excluded. Optimization was considered to be 50 mg/day or more of carvedilol, with a basal heart rate between 50 to 60 bpm that was maintained for 3 months. RESULTS Basal heart rate was lower in heart failure patients (57±3 bpm) compared to controls (89±14 bpm; p<0.0001). Similarly, the peak heart rate (% maximum predicted for age) was lower in HF patients (65.4±11.1%) compared to controls (98.6±2.2; p<0.0001). Maximum respiratory exchange ratio did not differ between the groups (1.2±0.5 for controls and 1.15±1 for heart failure patients; p=0.42). All controls reached the maximum heart rate for their age, while no patients in the heart failure group reached the maximum. Moreover, the % increase of heart rate from rest to peak exercise between heart failure (48±9%) and control (53±8%) was not different (p=0.157). CONCLUSION No patient in the heart failure group reached the maximum heart rate for their age during a treadmill cardiopulmonary exercise test, despite the fact that the percentage increase of heart rate was similar to sedentary normal subjects. A heart rate increase in optimized beta-blocked heart failure patients during cardiopulmonary exercise test over 65% of the maximum age-adjusted value should be considered an effort near the maximum. This information may be useful in rehabilitation programs and ischemic tests, although further studies are required. PMID:18719758

Speed ratio but cabin temperature positively correlated with increased heart rates among professional drivers during car races.

PubMed

Yanagida, Ryo; Takahashi, Kiichi; Miura, Masaru; Nomura, Masahiro; Ogawa, Yojiro; Aoki, Ken; Iwasaki, Ken-Ichi

2016-11-01

The present study measures heart rate (HR) on a number of professional race-car drivers during actual car races through annual seasons to test hypotheses that faster relative speed and higher cabin temperature would induce higher HR. Heart rates in fifteen male drivers (31.2 ± 5.5 years old) were obtained by chest-strap sensors during official-professional 13 races. Average HR was calculated while the driver was racing from the start to the end of each race. The average HR during races was 164.5 ± 15.1 beats min -1 and the average amount of time each driver spent driving per race was 54.2 ± 13.7 min. Average HR significantly and positively correlated with mean speed ratio (P < 0.001), but not with the average cabin temperatures (P = 0.533, range 25.6-41.8 °C) by the multiple linear regression analysis. Both average HR and mean speed ratio were significantly lower under wet, than dry conditions (151.9 ± 16.5 vs. 168.3 ± 12.5 beats min -1 , 86.9 ± 4.4 vs. 93.4 ± 1.5 %). The cardiovascular system of drivers is considerably stressed at extremely high HR. This high average HR positively correlated with mean speed ratio, suggesting that faster driving speed would induce greater cardiovascular stress to professional drivers during actual races. However, contrary to our hypothesis, cabin temperature was not significantly correlated with average HR. It is speculated that direct body cooling systems used in this professional race category work well against increases in HR by thermal stress under the temperature range found herein.

Effect of low-dose scopolamine on autonomic control of the heart

NASA Technical Reports Server (NTRS)

Raeder, E. A.; Stys, A.; Cohen, R. J.

1997-01-01

Background: In low doses, scopolamine paradoxically enhances parasympathetic outflow to the heart. The mechanisms which mediate this action are not fully understood. Moreover, there are conflicting data regarding the potential role of sympathetic activity. This study in 17 healthy individuals was designed to characterize the influence of low dose transdermal scopolamine on the gain of the baroreflex and respiratory heart rate reflex and to determine the role of sympathetic activity. Methods: The effect of scopolamine was analyzed in the time and frequency domain by computing heart rate variability indices. The gains of the respiratory heart rate reflex and the baroreflex were estimated simultaneously by means of a cardiovascular system identification approach using an optimized autoregressive moving average algorithm. Measurements were repeated in the upright posture to assess the influence of enhanced sympathetic activity. In six subjects ambulatory ECGs were recorded to determine whether there are diurnal variations of the effect of scopolamine. Results: Scopolamine enhances vagal modulation of heart rate through both the respiratory-heart rate reflex and the baroreflex, as the gains of both were augmented by the drug in the supine and in the upright postures. Conclusions: Scopolamine increases parasympathetic cardiac control by augmenting the gain of the respiratory-heart rate and baroreflex. This action is not attenuated in the upright posture when sympathetic tone is increased.

The effects of occupational noise on blood pressure and heart rate of workers in an automotive parts industry

PubMed Central

Kalantary, Saba; Dehghani, Ali; Yekaninejad, Mir Saeed; Omidi, Leila; Rahimzadeh, Mitra

2015-01-01

BACKGROUND One of the most important impacts of industrial noise is physiological and psychological effects. The increases in workers’ blood pressure and heart rate were detected during and after exposure to high levels of noise. The objectives of this research were to determine whether the noise exposures have any effects on blood pressure and heart rate of workers in the automotive parts industry. METHODS This case study was done in 2011 at different units of an automotive parts manufacturing in Tehran. Sound pressure level was measured at different units of the factory with a calibrated instrument. Demographic features of workers were gathered with an appropriate questionnaire. Heart rate and blood pressure were measured twice in a day in the start time of work day (before exposure to noise) and middle shift hours (during exposure to noise) in the occupational physician office. For analyzing data, chi-square, independent sample t-test, paired t-test, and analysis of covariance (ANCOVA) were used. P < 0.050 was considered statistically significant. RESULTS The average age of workers in the case and control groups was 35.71 ± 8.10 and 33.40 ± 10.41 years, respectively. There was no difference between the average age of case and control groups (P = 0.436). The results of ANCOVA revealed the significant differences between the mean changes of heart rate F (1, 37) = 26.68, P < 0.001, systolic blood pressure F (1, 37) = 21.70, P < 0.001, and diastolic blood pressure F (1, 37) = 26.20, P < 0.001 of workers in the case and control groups. CONCLUSION Exposure to industrial noise may increase the heart rate of workers. Although rises in heart rate, systolic, and diastolic blood pressure of workers in the case group were observed after exposure to noise, the values of heart rate, systolic, and diastolic blood pressure were in the normal range. Further experimental investigations are needed to determine the relationships between these variables. PMID:26478728

Effect of screen-based media on energy expenditure and heart rate in 9- to 12-year-old children.

PubMed

Straker, Leon; Abbott, Rebecca

2007-11-01

This study compared the cardiovascular responses and energy costs of new and traditional screen based entertainments, as played by twenty 9- to 12-year-old children. Playing traditional electronic games resulted in little change to heart rate or energy expenditure compared with watching a DVD. In contrast, playing an active-input game resulted in a 59% increase in heart rate (p < .001) and a 224% increase in energy expenditure (p < .001) for boys and girls. The average heart rate of 130 bpm and energy expenditure of 0.13 kcal . min-1 . kg-1 achieved during active-input game use equates with moderate intensity activities such as basketball and jogging. Active-input electronic games might provide children with opportunities to engage with technology and be physically active at the same time.

Heart Rate Response to a Timed Walk & Cardiovascular Outcomes in Older Adults: The Cardiovascular Health Study

PubMed Central

Girotra, Saket; Kitzman, Dalane W.; Kop, Willem J.; Stein, Phyllis K.; Gottdiener, John S.; Mukamal, Kenneth J.

2012-01-01

OBJECTIVES To determine the relationship between heart rate response during low-grade physical exertion (six-minute walk) with mortality and adverse cardiovascular outcomes in the elderly. METHODS Participants in the Cardiovascular Health Study, who completed a six-minute walk test, were included. We used delta heart rate (difference between post-walk heart rate and resting heart rate) as a measure of chronotropic response and examined its association with 1) all-cause mortality and 2) incident coronary heart disease (CHD) event, using multivariable Cox regression models. RESULTS We included 2224 participants (mean age 77±4 years; 60% women, 85% white). The average delta heart rate was 26 beats/min. Participants in the lowest tertile of delta heart rate (<20 beats/min) had higher risk-adjusted mortality (hazard ratio [HR] 1.18; 95% confidence interval [CI][1.00, 1.40]) and incident CHD (HR 1.37; 95% CI[1.05, 1.78]) compared to subjects in the highest tertile (≥30 beats/min), with a significant linear trend across tertiles (P for trend <0.05 for both outcomes). This relationship was not significant after adjustment for distance walked. CONCLUSION Impaired chronotropic response during six-minute walk test was associated with an increased risk of mortality and incident CHD among the elderly. This association was attenuated after adjusting for distance walked. PMID:22722364

Spectrum-averaged Harmonic Path (SHAPA) algorithm for non-contact vital sign monitoring with ultra-wideband (UWB) radar.

PubMed

Van Nguyen; Javaid, Abdul Q; Weitnauer, Mary Ann

2014-01-01

We introduce the Spectrum-averaged Harmonic Path (SHAPA) algorithm for estimation of heart rate (HR) and respiration rate (RR) with Impulse Radio Ultrawideband (IR-UWB) radar. Periodic movement of human torso caused by respiration and heart beat induces fundamental frequencies and their harmonics at the respiration and heart rates. IR-UWB enables capture of these spectral components and frequency domain processing enables a low cost implementation. Most existing methods of identifying the fundamental component either in frequency or time domain to estimate the HR and/or RR lead to significant error if the fundamental is distorted or cancelled by interference. The SHAPA algorithm (1) takes advantage of the HR harmonics, where there is less interference, and (2) exploits the information in previous spectra to achieve more reliable and robust estimation of the fundamental frequency in the spectrum under consideration. Example experimental results for HR estimation demonstrate how our algorithm eliminates errors caused by interference and produces 16% to 60% more valid estimates.

Evaluation of in-hospital electrocardiography versus 24-hour Holter for rate control in dogs with atrial fibrillation.

PubMed

Gelzer, A R; Kraus, M S; Rishniw, M

2015-07-01

To determine if the in-clinic ECG-derived heart rate could predict the at-home Holter-derived 24-hour average heart rate (Holter24h ), and whether it is useful to identify slow versus fast atrial fibrillation in dogs. 82 pairs of 1-minute ECGs and 24-hour Holter recordings were acquired in 34 dogs with atrial fibrillation. The initial 24-hour Holter was used to test if the ECG heart rate can identify dogs with "slow" versus "fast" atrial fibrillation based on a Holter24h threshold value of 140 bpm. ECG heart rate overestimated Holter24h by 26 bpm (95% CI: 3 bpm, 48 bpm; P < 0 · 015) with a 95% limit of agreement of -21 to 83 bpm. The in-clinic ECG-derived heart rate Ä155 bpm had a sensitivity of 73% and a specificity of 100% for identifying a Holter24h HR Ä140 bpm; an in-clinic ECG-derived HR <160 bpm had a sensitivity and specificity of 91% each. In-clinic ECG assessment of heart rate in dogs with atrial fibrillation does not reliably predict the heart rate in their home environment. However, an in-clinic heart rate greater than 155 bpm is useful in identifying "fast" atrial fibrillation, allowing clinicians to stratify which case may benefit from antiarrhythmic therapy. © 2015 British Small Animal Veterinary Association.

Sex differences in the fetal heart rate variability indices of twins.

PubMed

Tendais, Iva; Figueiredo, Bárbara; Gonçalves, Hernâni; Bernardes, João; Ayres-de-Campos, Diogo; Montenegro, Nuno

2015-03-01

To evaluate the differences in linear and complex heart rate dynamics in twin pairs according to fetal sex combination [male-female (MF), male-male (MM), and female-female (FF)]. Fourteen twin pairs (6 MF, 3 MM, and 5 FF) were monitored between 31 and 36.4 weeks of gestation. Twenty-six fetal heart rate (FHR) recordings of both twins were simultaneously acquired and analyzed with a system for computerized analysis of cardiotocograms. Linear and nonlinear FHR indices were calculated. Overall, MM twins presented higher intrapair average in linear indices than the other pairs, whereas FF twins showed higher sympathetic-vagal balance. MF twins exhibited higher intrapair average in entropy indices and MM twins presented lower entropy values than FF twins considering the (automatically selected) threshold rLu. MM twin pairs showed higher intrapair differences in linear heart rate indices than MF and FF twins, whereas FF twins exhibited lower intrapair differences in entropy indices. The results of this exploratory study suggest that twins have sex-specific differences in linear and nonlinear indices of FHR. MM twins expressed signs of a more active autonomic nervous system and MF twins showed the most active complexity control system. These results suggest that fetal sex combination should be taken into consideration when performing detailed evaluation of the FHR in twins.

Power output of field-based downhill mountain biking.

PubMed

Hurst, Howard Thomas; Atkins, Stephen

2006-10-01

The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 +/- 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 +/- 129 W and 75 +/- 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 +/- 9 beats x min(-1) (89% of age-predicted maximum heart rate). Mean cadence (27 +/- 5 rev x min(-1)) was significantly related to speed (r = 0.51; P < 0.01). Analysis revealed an average of 38 pedal actions per run, with average pedalling periods of 5 s. Power and cadence were not significantly related to run time or any other variable. Our results support the intermittent nature of downhill mountain biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.

Context Specificity of the ANS Stress Response during Two Regrouping Experiments in Goats

PubMed Central

Patt, Antonia; Gygax, Lorenz; Wechsler, Beat; Hillmann, Edna; Langbein, Jan; Keil, Nina M.

2016-01-01

The aim of this study was to analyze whether the activity of the autonomic nervous system (ANS) differs between two regrouping procedures in goats, which would indicate stimulus specificity of these stressors. Applying two regrouping procedures, we evaluated heart rate and heart rate variability (RMSSD, SDNN, and RMSSD/SDNN). The two regrouping procedures were (1) introduction of individual goats into established groups (“introduction experiment”) and (2) temporary separation and subsequent reintegration of individuals from/into their group with two levels of contact during separation (“separation experiment”). In the “introduction experiment,” the heart rate of introduced goats while lying decreased continuously from an average 78 to 68 beats/min from before the introduction to the last day of the introduction period. Inversely, RMSSD increased continuously from 41 to 62 ms, which, on its own, would indicate an adaptation to the situation. During the “separation experiment,” heart rate while lying was higher when goats were separated in the “acoustic contact treatment” (82 beats/min on average) compared with the “restricted physical contact treatment” (75 beats/min on average). This difference reflected a higher level of arousal during the “acoustic contact treatment.” However, heart rate activity did not allow detecting effects of separation or reintegration. Even though it can be assumed that both the separation and introduction of goats are stressful for goats, the ANS reactions observed in this study differed between the two management procedures indicating that the ANS activation was specific to each situation. In addition, we discuss the ANS results in context with earlier findings of variables of the hypothalamic pituitary adrenal (HPA) axis (fecal cortisol metabolites) and behavior (lying and feeding). As correspondence between ANS, HPA, and behavioral reactions was limited both within and across experiments, the results of this study underline the concept that stress response patterns are context specific. PMID:27551679

Cardiovascular and Cerebrovascular Control on Return from International Space Station (CCISS)- Heart Rate and Activity

NASA Astrophysics Data System (ADS)

Hughson, R. L.; Shoemaker, J. K.; Blaber, A. P.; Arbeille, Ph.; Zuj, K. A.; Greaves, D. K.

2008-06-01

CCISS is a project to study the cardiovascular and cerebrovascular responses of astronauts before, during and after long-duration (>60-day) stays on the International Space Station. The CCISS experiments consist of three phases that are designed to achieve an integrated examination of components responsible for return of blood to the heart, the pumping of blood from the heart and the distribution to the vascular territories including the brain. In this report the data are obtained from the 24-h monitoring of physical activity (Actiwatch on wrist and ankle) and of heart rate (Holter monitor). The data show clear patterns of change in physical activity from predominantly leg-based on Earth to relatively little activity of the ankles with maintained or increased activity of the wrists on ISS. Both on Earth and on ISS the largest changes in heart rate occur during the periods of leg activity. Average heart rate was changed little during the periods of minimal activity or of sleep in comparisons of Earth with in-flight recording both within the first two weeks of flight and the last two weeks. These data clearly show the importance of monitoring heart rate and physical activity simultaneously and show that attempts to derive indicators of autonomic activity from spectral analysis of heart rate variability should not be performed in the absence of knowledge of both variables.

Caffeine affects cardiovascular and neuroendocrine activation at work and home.

PubMed

Lane, James D; Pieper, Carl F; Phillips-Bute, Barbara G; Bryant, John E; Kuhn, Cynthia M

2002-01-01

This study investigated the effects of moderate doses of caffeine on ambulatory blood pressure and heart rate, urinary excretion of epinephrine, norepinephrine, and cortisol, and subjective measures of stress during normal activities at work and at home in the evening. Healthy, nonsmoking, habitual coffee drinkers (N = 47) participated in 3 days of ambulatory study. After a day of ad lib caffeine consumption, caffeine (500 mg) and placebo were administered double-blind in counter-balanced order on separate workdays. Ambulatory blood pressure and heart rate were monitored from the start of the workday until bedtime. Urinary excretion of catecholamines and cortisol was assessed during the workday and evening. Caffeine administration significantly raised average ambulatory blood pressure during the workday and evening by 4/3 mm Hg and reduced average heart rate by 2 bpm. Caffeine also increased by 32% the levels of free epinephrine excreted during the workday and the evening. In addition, caffeine amplified the increases in blood pressure and heart rate associated with higher levels of self-reported stress during the activities of the day. Effects were undiminished through the evening until bedtime. Caffeine has significant hemodynamic and humoral effects in habitual coffee drinkers that persist for many hours during the activities of everyday life. Furthermore, caffeine may exaggerate sympathetic adrenal-medullary responses to the stressful events of normal daily life. Repeated daily blood pressure elevations and increases in stress reactivity caused by caffeine consumption could contribute to an increased risk of coronary heart disease in the adult population.

Speed and heart-rate profiles in skating and classical cross-country skiing competitions.

PubMed

Bolger, Conor M; Kocbach, Jan; Hegge, Ann Magdalen; Sandbakk, Øyvind

2015-10-01

To compare the speed and heart-rate profiles during international skating and classical competitions in male and female world-class cross-country skiers. Four male and 5 female skiers performed individual time trials of 15 km (men) and 10 km (women) in the skating and classical techniques on 2 consecutive days. Races were performed on the same 5-km course. The course was mapped with GPS and a barometer to provide a valid course and elevation profile. Time, speed, and heart rate were determined for uphill, flat, and downhill terrains throughout the entire competition by wearing a GPS and a heart-rate monitor. Times in uphill, flat, and downhill terrain were ~55%, 15-20%, and 25-30%, respectively, of the total race time for both techniques and genders. The average speed differences between skating and classical skiing were 9% and 11% for men and women, respectively, and these values were 12% and 15% for uphill, 8% and 13% for flat (all P < .05), and 2% and 1% for downhill terrain. The average speeds for men were 9% and 11% faster than for women in skating and classical, respectively, with corresponding numbers of 11% and 14% for uphill, 6% and 11% for flat, and 4% and 5% for downhill terrain (all P < .05). Heart-rate profiles were relatively independent of technique and gender. The greatest performance differences between the skating and classical techniques and between the 2 genders were found on uphill terrain. Therefore, these speed differences could not be explained by variations in exercise intensity.

Investigating the limitations of single breath-hold renal artery blood flow measurements using spiral phase contrast MR with R-R interval averaging.

PubMed

Steeden, Jennifer A; Muthurangu, Vivek

2015-04-01

1) To validate an R-R interval averaged golden angle spiral phase contrast magnetic resonance (RAGS PCMR) sequence against conventional cine PCMR for assessment of renal blood flow (RBF) in normal volunteers; and 2) To investigate the effects of motion and heart rate on the accuracy of flow measurements using an in silico simulation. In 20 healthy volunteers RAGS (∼6 sec breath-hold) and respiratory-navigated cine (∼5 min) PCMR were performed in both renal arteries to assess RBF. A simulation of RAGS PCMR was used to assess the effect of heart rate (30-105 bpm), vessel expandability (0-150%) and translational motion (x1.0-4.0) on the accuracy of RBF measurements. There was good agreement between RAGS and cine PCMR in the volunteer study (bias: 0.01 L/min, limits of agreement: -0.04 to +0.06 L/min, P = 0.0001). The simulation demonstrated a positive linear relationship between heart rate and error (r = 0.9894, P < 0.0001), a negative linear relationship between vessel expansion and error (r = -0.9484, P < 0.0001), and a nonlinear, heart rate-dependent relationship between vessel translation and error. We have demonstrated that RAGS PCMR accurately measures RBF in vivo. However, the simulation reveals limitations in this technique at extreme heart rates (<40 bpm, >100 bpm), or when there is significant motion (vessel expandability: >80%, vessel translation: >x2.2). © 2014 Wiley Periodicals, Inc.

Knowledge of resting heart rate mediates the relationship between intelligence and the heartbeat counting task.

PubMed

Murphy, Jennifer; Millgate, Edward; Geary, Hayley; Ichijo, Eri; Coll, Michel-Pierre; Brewer, Rebecca; Catmur, Caroline; Bird, Geoffrey

2018-03-01

Evidence suggests that intelligence is positively associated with performance on the heartbeat counting task (HCT). The HCT is often employed as measure of interoception - the ability to perceive the internal state of one's body - however it's use remains controversial as performance on the HCT is strongly influenced by knowledge of resting heart rate. This raises the possibility that heart rate knowledge may mediate the previously-observed association between intelligence and HCT performance. Study One demonstrates an association between intelligence and HCT performance (N = 94), and Study Two demonstrates that this relationship is mediated by knowledge of the average resting heart rate (N = 134). These data underscore the need to account for the influence of prior knowledge and beliefs when examining individual differences in cardiac interoceptive accuracy using the HCT. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Sudden cardiac death rates in an Australian population: a data linkage study.

PubMed

Feng, Jia-Li; Hickling, Siobhan; Nedkoff, Lee; Knuiman, Matthew; Semsarian, Christopher; Ingles, Jodie; Briffa, Tom G

2015-11-01

The aim of the present study was to develop criteria to identify sudden cardiac death (SCD) and estimate population rates of SCD using administrative mortality and hospital morbidity records in Western Australia. Four criteria were developed using place, death within 24 h, principal and secondary diagnoses, underlying and associated cause of death, and/or occurrence of a post mortem to identify SCD. Average crude, age-standardised and age-specific rates of SCD were estimated using population person-linked administrative data. In all, 9567 probable SCDs were identified between 1997 and 2010, with one-third aged ≥ 35 years having no prior admission for cardiovascular disease. SCD was more frequent in men (62.1%). The estimated average annual crude SCD rate for the period was 34.6 per 100 000 person-years with an average annual age-standardised rate of 37.8 per 100 000 person-years. Age-specific standardised rates were 1.1 per 100 000 person-years and 70.7 per 100 000 person-years in people aged 1-34 and ≥ 35 years, respectively. Ischaemic heart disease (IHD) was recorded as the underlying cause of death in approximately 80% of patients aged ≥ 35 years, followed by valvular heart disease and heart failure. IHD was the most common cause of death in those aged 1-34 years, followed by unspecified cardiomyopathy and dysrhythmias. Administrative morbidity and mortality data can be used to estimate rates of SCD and therefore provide a suitable methodology for monitoring SCD over time. The findings highlight the magnitude of SCD and its potential for public health prevention.

TROIKA: a general framework for heart rate monitoring using wrist-type photoplethysmographic signals during intensive physical exercise.

PubMed

Zhang, Zhilin; Pi, Zhouyue; Liu, Benyuan

2015-02-01

Heart rate monitoring using wrist-type photoplethysmographic signals during subjects' intensive exercise is a difficult problem, since the signals are contaminated by extremely strong motion artifacts caused by subjects' hand movements. So far few works have studied this problem. In this study, a general framework, termed TROIKA, is proposed, which consists of signal decomposiTion for denoising, sparse signal RecOnstructIon for high-resolution spectrum estimation, and spectral peaK trAcking with verification. The TROIKA framework has high estimation accuracy and is robust to strong motion artifacts. Many variants can be straightforwardly derived from this framework. Experimental results on datasets recorded from 12 subjects during fast running at the peak speed of 15 km/h showed that the average absolute error of heart rate estimation was 2.34 beat per minute, and the Pearson correlation between the estimates and the ground truth of heart rate was 0.992. This framework is of great values to wearable devices such as smartwatches which use PPG signals to monitor heart rate for fitness.

Development and significance of a fetal electrocardiogram recorded by signal-averaged high-amplification electrocardiography.

PubMed

Hayashi, Risa; Nakai, Kenji; Fukushima, Akimune; Itoh, Manabu; Sugiyama, Toru

2009-03-01

Although ultrasonic diagnostic imaging and fetal heart monitors have undergone great technological improvements, the development and use of fetal electrocardiograms to evaluate fetal arrhythmias and autonomic nervous activity have not been fully established. We verified the clinical significance of the novel signal-averaged vector-projected high amplification ECG (SAVP-ECG) method in fetuses from 48 gravidas at 32-41 weeks of gestation and in 34 neonates. SAVP-ECGs from fetuses and newborns were recorded using a modified XYZ-leads system. Once noise and maternal QRS waves were removed, the P, QRS, and T wave intervals were measured from the signal-averaged fetal ECGs. We also compared fetal and neonatal heart rates (HRs), coefficients of variation of heart rate variability (CV) as a parasympathetic nervous activity, and the ratio of low to high frequency (LF/HF ratio) as a sympathetic nervous activity. The rate of detection of a fetal ECG by SAVP-ECG was 72.9%, and the fetal and neonatal QRS and QTc intervals were not significantly different. The neonatal CVs and LF/HF ratios were significantly increased compared with those in the fetus. In conclusion, we have developed a fetal ECG recording method using the SAVP-ECG system, which we used to evaluate autonomic nervous system development.

Prognostic value of heart rate variability footprint and standard deviation of average 5-minute intrinsic R-R intervals for mortality in cardiac resynchronization therapy patients.

PubMed

Gilliam, F Roosevelt; Singh, Jagmeet P; Mullin, Christopher M; McGuire, Maureen; Chase, Kellie J

2007-10-01

Cardiac resynchronization therapy devices provide effective therapy for heart failure. Heart rate variability (HRV) parameters in the device such as HRV footprint and SD of average 5-minute intrinsic R-R intervals (SDANN) are related to autonomic function and may be used to identify patients with a higher risk of mortality. We examined the relationship between HRV and mortality in a prospective cohort study. The 842 patients (mean age, 67.7 +/- 11.2; 23.5 % female; New York Heart Association class III, 88.6%; class IV, 11.4%) included in the analysis were implanted with a cardiac resynchronization therapy with defibrillation device and had baseline HRV measurements available. During a median of 11.6 months of follow-up, 7.8% (66/842) of patients died. Heart rate variability footprint and SDANN were significant predictors of mortality (all P < .05); patients with lower HRV values were at greater risk for death, compared with patients with higher HRV values. Heart rate variability changes over time tended to predict the risk of mortality in follow-up (P = nonsignificant); patients with low baseline HRV and small changes in HRV during the follow-up period were at the highest risk for death (7% mortality for SDANN and 8.9% for HRV footprint), and patients with high baseline HRV and large changes in HRV were at the lowest risk (1.5% mortality for SDANN and 2.4% for HRV footprint). Results were consistent when adjusted for age, sex, body mass index, and diastolic blood pressure. Continuously measured device HRV parameters provide prognostic information about patient mortality that may be helpful for risk stratification.

Minute ventilation of cyclists, car and bus passengers: an experimental study.

PubMed

Zuurbier, Moniek; Hoek, Gerard; van den Hazel, Peter; Brunekreef, Bert

2009-10-27

Differences in minute ventilation between cyclists, pedestrians and other commuters influence inhaled doses of air pollution. This study estimates minute ventilation of cyclists, car and bus passengers, as part of a study on health effects of commuters' exposure to air pollutants. Thirty-four participants performed a submaximal test on a bicycle ergometer, during which heart rate and minute ventilation were measured simultaneously at increasing cycling intensity. Individual regression equations were calculated between heart rate and the natural log of minute ventilation. Heart rates were recorded during 280 two hour trips by bicycle, bus and car and were calculated into minute ventilation levels using the individual regression coefficients. Minute ventilation during bicycle rides were on average 2.1 times higher than in the car (individual range from 1.3 to 5.3) and 2.0 times higher than in the bus (individual range from 1.3 to 5.1). The ratio of minute ventilation of cycling compared to travelling by bus or car was higher in women than in men. Substantial differences in regression equations were found between individuals. The use of individual regression equations instead of average regression equations resulted in substantially better predictions of individual minute ventilations. The comparability of the gender-specific overall regression equations linking heart rate and minute ventilation with one previous American study, supports that for studies on the group level overall equations can be used. For estimating individual doses, the use of individual regression coefficients provides more precise data. Minute ventilation levels of cyclists are on average two times higher than of bus and car passengers, consistent with the ratio found in one small previous study of young adults. The study illustrates the importance of inclusion of minute ventilation data in comparing air pollution doses between different modes of transport.

Prognostic impact of intestinal wall thickening in hospitalized patients with heart failure.

PubMed

Ikeda, Yuki; Ishii, Shunsuke; Fujita, Teppei; Iida, Yuichiro; Kaida, Toyoji; Nabeta, Takeru; Maekawa, Emi; Yanagisawa, Tomoyoshi; Koitabashi, Toshimi; Takeuchi, Ichiro; Inomata, Takayuki; Ako, Junya

2017-03-01

Intestine-cardiovascular relationship has been increasingly recognized as a key factor in patients with heart disease. We aimed to identify the relationships among intestinal wall edema, cardiac function, and adverse clinical events in hospitalized heart failure (HF) patients. Abdominal computed tomographic images of 168 hospitalized HF patients were retrospectively investigated for identification of average colon wall thickness (CWT) from the ascending to sigmoid colon. Relationships between average CWT and echocardiographic parameters, blood sampling data, and primary outcomes including readmission for deteriorated HF and all-cause mortality were evaluated. Among the echocardiographic parameters, lower left ventricular diastolic function was correlated with higher average CWT. In multivariate analysis, higher logarithmic C-reactive protein level, lower estimated glomerular filtration rate, lower peripheral blood lymphocyte count, higher E/E' ratio, and extremely higher/lower defecation frequency were independently correlated with higher average CWT. Multivariate Cox-hazard analysis demonstrated that higher average CWT was independently related to higher incidence of primary outcomes. In hospitalized HF patients, increased CWT was associated with lower cardiac performance, and predicted poorer long-term clinical outcomes. Copyright © 2016. Published by Elsevier B.V.

Spot measurement of heart rate based on morphology of PhotoPlethysmoGraphic (PPG) signals.

PubMed

Madhan Mohan, P; Nagarajan, V; Vignesh, J C

2017-02-01

Due to increasing health consciousness among people, it is imperative to have low-cost health care devices to measure the vital parameters like heart rate and arterial oxygen saturation (SpO 2 ). In this paper, an efficient heart rate monitoring algorithm based on the morphology of photoplethysmography (PPG) signals to measure the spot heart rate (HR) and its real-time implementation is proposed. The algorithm does pre-processing and detects the onsets and systolic peaks of the PPG signal to estimate the heart rate of the subject. Since the algorithm is based on the morphology of the signal, it works well when the subject is not moving, which is a typical test case. So, this algorithm is developed mainly to measure the heart rate at on-demand applications. Real-time experimental results indicate the heart rate accuracy of 99.5%, mean absolute percentage error (MAPE) of 1.65%, mean absolute error (MAE) of 1.18 BPM and reference closeness factor (RCF) of 0.988. The results further show that the average response time of the algorithm to give the spot HR is 6.85 s, so that the users need not wait longer to see their HR. The hardware implementation results show that the algorithm only requires 18 KBytes of total memory and runs at high speed with 0.85 MIPS. So, this algorithm can be targeted to low-cost embedded platforms.

Association Between Energy Prices and US Hospital Patient Outcomes.

PubMed

Brown, Lawrence H; Chaiechi, Taha; Buettner, Petra G; Canyon, Deon V

2017-04-01

To evaluate associations between changing energy prices and US hospital patient outcomes. Generalized estimating equations were used to analyze relationships between changes in energy prices and subsequent changes in hospital patient outcomes measures for the years 2008 through 2014. Patient outcomes measures included 30-day acute myocardial infarction, heart failure, and pneumonia mortality rates, and 30-day acute myocardial infarction, heart failure, and pneumonia readmission rates. Energy price data included state average distillate fuel, electricity and natural gas prices, and the US average coal price. All of the price data were converted to 2014 dollars using Consumer Price Index multipliers. There was a significant positive association between changes in coal price and both short-term ( P = 0.029) and long-term ( P = 0.017) changes in the 30-day heart failure mortality rate. There was a similar significant positive association between changes in coal price and both short-term ( P <0.001) and long-term ( P = 0.002) changes in the 30-day pneumonia mortality rate. Changes in coal prices also were positively associated with long-term changes in the 30-day myocardial infarction readmission rate ( P < 0.001). Changes in coal prices ( P = 0.20), natural gas prices ( P = 0.040), and electricity prices ( P = 0.040) were positively associated with long-term changes in the 30-day heart failure readmission rate. Changing energy prices are associated with subsequent changes in hospital mortality and readmission measures. In light of these data, we encourage hospital, health system, and health policy leaders to pursue patient-support initiatives, energy conservation programs, and reimbursement policy strategies aimed at mitigating those effects.

Are You Bleeding? Validation of a Machine-learning Algorithm for Determination of Blood Volume Status: Application to Remote Triage

DTIC Science & Technology

2014-01-09

workloads were determined by matching heart rate responses from each LBNP level. Heart rate and stroke volume (SV) were measured via Finom- eter. ECG, heat...learning algorithm for the assessment of central blood volume via pulse pressure [a noninvasive surrogate of stroke volume (SV)]. These data...30 130 125 120 115 110 105 100 Actual - Finometer Predicted - Algorithm Fig. 3. Comparison of average stroke volume (SV) derived from the

Speed and Cardiac Recovery Variables Predict the Probability of Elimination in Equine Endurance Events

PubMed Central

Younes, Mohamed; Robert, Céline; Cottin, François; Barrey, Eric

2015-01-01

Nearly 50% of the horses participating in endurance events are eliminated at a veterinary examination (a vet gate). Detecting unfit horses before a health problem occurs and treatment is required is a challenge for veterinarians but is essential for improving equine welfare. We hypothesized that it would be possible to detect unfit horses earlier in the event by measuring heart rate recovery variables. Hence, the objective of the present study was to compute logistic regressions of heart rate, cardiac recovery time and average speed data recorded at the previous vet gate (n-1) and thus predict the probability of elimination during successive phases (n and following) in endurance events. Speed and heart rate data were extracted from an electronic database of endurance events (80–160 km in length) organized in four countries. Overall, 39% of the horses that started an event were eliminated—mostly due to lameness (64%) or metabolic disorders (15%). For each vet gate, logistic regressions of explanatory variables (average speed, cardiac recovery time and heart rate measured at the previous vet gate) and categorical variables (age and/or event distance) were computed to estimate the probability of elimination. The predictive logistic regressions for vet gates 2 to 5 correctly classified between 62% and 86% of the eliminated horses. The robustness of these results was confirmed by high areas under the receiving operating characteristic curves (0.68–0.84). Overall, a horse has a 70% chance of being eliminated at the next gate if its cardiac recovery time is longer than 11 min at vet gate 1 or 2, or longer than 13 min at vet gates 3 or 4. Heart rate recovery and average speed variables measured at the previous vet gate(s) enabled us to predict elimination at the following vet gate. These variables should be checked at each veterinary examination, in order to detect unfit horses as early as possible. Our predictive method may help to improve equine welfare and ethical considerations in endurance events. PMID:26322506

Speed and Cardiac Recovery Variables Predict the Probability of Elimination in Equine Endurance Events.

PubMed

Younes, Mohamed; Robert, Céline; Cottin, François; Barrey, Eric

2015-01-01

Nearly 50% of the horses participating in endurance events are eliminated at a veterinary examination (a vet gate). Detecting unfit horses before a health problem occurs and treatment is required is a challenge for veterinarians but is essential for improving equine welfare. We hypothesized that it would be possible to detect unfit horses earlier in the event by measuring heart rate recovery variables. Hence, the objective of the present study was to compute logistic regressions of heart rate, cardiac recovery time and average speed data recorded at the previous vet gate (n-1) and thus predict the probability of elimination during successive phases (n and following) in endurance events. Speed and heart rate data were extracted from an electronic database of endurance events (80-160 km in length) organized in four countries. Overall, 39% of the horses that started an event were eliminated--mostly due to lameness (64%) or metabolic disorders (15%). For each vet gate, logistic regressions of explanatory variables (average speed, cardiac recovery time and heart rate measured at the previous vet gate) and categorical variables (age and/or event distance) were computed to estimate the probability of elimination. The predictive logistic regressions for vet gates 2 to 5 correctly classified between 62% and 86% of the eliminated horses. The robustness of these results was confirmed by high areas under the receiving operating characteristic curves (0.68-0.84). Overall, a horse has a 70% chance of being eliminated at the next gate if its cardiac recovery time is longer than 11 min at vet gate 1 or 2, or longer than 13 min at vet gates 3 or 4. Heart rate recovery and average speed variables measured at the previous vet gate(s) enabled us to predict elimination at the following vet gate. These variables should be checked at each veterinary examination, in order to detect unfit horses as early as possible. Our predictive method may help to improve equine welfare and ethical considerations in endurance events.

Retrospective Evaluation of the Effect of Heart Rate on Survival in Dogs with Atrial Fibrillation.

PubMed

Pedro, B; Dukes-McEwan, J; Oyama, M A; Kraus, M S; Gelzer, A R

2018-01-01

Atrial fibrillation (AF) usually is associated with a rapid ventricular rate. The optimal heart rate (HR) during AF is unknown. Heart rate affects survival in dogs with chronic AF. Forty-six dogs with AF and 24-hour ambulatory recordings were evaluated. Retrospective study. Holter-derived HR variables were analyzed as follows: mean HR (meanHR, 24-hour average), minimum HR (minHR, 1-minute average), maximum HR (maxHR, 1-minute average). Survival times were recorded from the time of presumed adequate rate control. The primary endpoint was all-cause mortality. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan-Meier survival analysis estimated the median survival time of dogs with meanHR <125 bpm versus ≥125 bpm. All 46 dogs had structural heart disease; 31 of 46 had congestive heart failure (CHF), 44 of 46 received antiarrhythmic drugs. Of 15 dogs with cardiac death, 14 had CHF. Median time to all-cause death was 524 days (Interquartile range (IQR), 76-1,037 days). MeanHR was 125 bpm (range, 62-203 bpm), minHR was 82 bpm (range, 37-163 bpm), maxHR was 217 bpm (range, 126-307 bpm). These were significantly correlated with all-cause and cardiac-related mortality. For every 10 bpm increase in meanHR, the risk of all-cause mortality increased by 35% (hazard ratio, 1.35; 95% CI, 1.17-1.55; P < 0.001). Median survival time of dogs with meanHR<125 bpm (n = 23) was significantly longer (1,037 days; range, 524-open) than meanHR ≥125 bpm (n = 23; 105 days; range, 67-267 days; P = 0.0012). Mean HR was independently associated with all-cause and cardiovascular mortality (P < 0.003). Holter-derived meanHR affects survival in dogs with AF. Dogs with meanHR <125 bpm lived longer than those with meanHR ≥ 125 bpm. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Heart rate and suicide: findings from two cohorts of 533 000 Taiwanese and 75 000 Norwegian adults.

PubMed

Chang, S-S; Bjørngaard, J H; Tsai, M K; Bjerkeset, O; Wen, C P; Yip, P S F; Tsao, C K; Gunnell, D

2016-04-01

To investigate the association of resting heart rate with suicide in two large cohorts. The MJ cohort (Taiwan) included 532 932 adults from a health check-up programme (1994-2008). The HUNT cohort (Norway) included 74 977 adults in the Nord-Trøndelag County study (1984-1986), followed up to 2004. In both cohorts heart rate was measured at baseline, and suicide was ascertained through linkage to cause-of-death registers. Risk of suicide was estimated using Cox proportional hazards models. There were 569 and 188 suicides (average follow-up period of 8.1 and 16.9 years) in the MJ and HUNT cohorts respectively. Sex- and age-adjusted hazard ratio for every 10 beat increase in heart rate per minute was 1.08 (95% Confidence Interval 1.00-1.16) and 1.24 (1.12-1.38) in the MJ and HUNT cohorts, respectively. In the MJ cohort this association was confined to individuals with a history of heart diseases vs. those without such a history (P for interaction = 0.008). In the HUNT cohort the association did not differ by history of heart diseases and was robust to adjustment for health-related life style, medication use, and symptoms of anxiety and depression. Elevated resting heart rate may be a marker of increased suicide risk. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Practical remarks on the heart rate and saturation measurement methodology

NASA Astrophysics Data System (ADS)

Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.

2017-05-01

A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.

Heart rate prediction for coronary artery disease patients (CAD): Results of a clinical pilot study.

PubMed

Müller-von Aschwege, Frerk; Workowski, Anke; Willemsen, Detlev; Müller, Sebastian M; Hein, Andreas

2015-01-01

This paper describes the results of a pilot study with cardiac patients based on information that can be derived from a smartphone. The idea behind the study is to design a model for estimating the heart rate of a patient before an outdoor walking session for track planning, as well as using the model for guidance during an outdoor session. The model allows estimation of the heart rate several minutes in advance to guide the patient and avoid overstrain before its occurrence. This paper describes the first results of the clinical pilot study with cardiac patients taking β-blockers. 9 patients have been tested on a treadmill and during three outdoor sessions each. The results have been derived and three levels of improvement have been tested by cross validation. The overall result is an average Median Absolute Deviation (MAD) of 4.26 BPM between measured heart rate and smartphone sensor based model estimation.

Inhalation of ultrafine carbon particles alters heart rate and heart rate variability in people with type 2 diabetes.

PubMed

Vora, Rathin; Zareba, Wojciech; Utell, Mark J; Pietropaoli, Anthony P; Chalupa, David; Little, Erika L; Oakes, David; Bausch, Jan; Wiltshire, Jelani; Frampton, Mark W

2014-07-16

Diabetes may confer an increased risk for the cardiovascular health effects of particulate air pollution, but few human clinical studies of air pollution have included people with diabetes. Ultrafine particles (UFP, ≤100 nm in diameter) have been hypothesized to be an important component of particulate air pollution with regard to cardiovascular health effects. 17 never-smoker subjects 30-60 years of age, with stable type 2 diabetes but otherwise healthy, inhaled either filtered air (0-10 particles/cm3) or elemental carbon UFP (~107 particles/cm3, ~50 ug/m3, count median diameter 32 nm) by mouthpiece, for 2 hours at rest, in a double-blind, randomized, crossover study design. A digital 12-lead electrocardiogram (ECG) was recorded continuously for 48 hours, beginning 1 hour prior to exposure. Analysis of 5-minute segments of the ECG during quiet rest showed reduced high-frequency heart rate variability with UFP relative to air exposure (p = 0.014), paralleled by non-significant reductions in time-domain heart rate variability parameters. In the analysis of longer durations of the ECG, we found that UFP exposure increased the heart rate relative to air exposure. During the 21- to 45-hour interval after exposure, the average heart rate increased approximately 8 beats per minute with UFP, compared to 5 beats per minute with air (p = 0.045). There were no UFP effects on cardiac rhythm or repolarization. Inhalation of elemental carbon ultrafine particles alters heart rate and heart rate variability in people with type 2 diabetes. Our findings suggest that effects may occur and persist hours after a single 2-hour exposure.

Prognostic capacity of a clinically indicated exercise test for cardiovascular mortality is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans.

PubMed

Minkkinen, Mikko; Nieminen, Tuomo; Verrier, Richard L; Leino, Johanna; Lehtimäki, Terho; Viik, Jari; Lehtinen, Rami; Nikus, Kjell; Kööbi, Tiit; Turjanmaa, Väinö; Kähönen, Mika

2015-09-01

Exercise capacity, heart rate recovery and T-wave alternans are independent predictors of cardiovascular mortality. We tested whether these parameters contain supplementary prognostic information. A total of 3609 consecutive patients (2157 men) referred for a routine, clinically indicated bicycle exercise test were enrolled in the Finnish Cardiovascular Study (FINCAVAS). Exercise capacity was measured in metabolic equivalents, heart rate recovery as the decrease in heart rate from maximum to one minute post-exercise, and T-wave alternans by time-domain Modified Moving Average method. During 57-month median follow-up (interquartile range 35-78 months), 96 patients died of cardiovascular causes (primary endpoint) and 233 from any cause. All three parameters were independent predictors of cardiovascular mortality when analysed as continuous variables. Adding metabolic equivalents (p < 0.001), heart rate recovery (p = 0.002) or T-wave alternans (p = 0.01) to the linear model improved its predictive power for cardiovascular mortality. The combination of low exercise capacity (<6 metabolic equivalents), reduced heart rate recovery (≤12 beats/min) and elevated T-wave alternans (≥60 μV) yielded the highest hazard ratio for cardiovascular mortality of 16.5 (95% confidence interval 4.0-67.7, p < 0.001). Harrell's C index was 0.719 (confidence interval 0.665-0.772) for cardiovascular mortality with previously defined cutpoints (<8 units for metabolic equivalents, ≤18 beats/min for heart rate recovery and ≥60 μV for T-wave alternans). The prognostic capacity of the clinical exercise test is enhanced by combined analysis of exercise capacity, heart rate recovery and T-wave alternans. © The European Society of Cardiology 2014.

Comparison Between Prospectively Electrocardiogram-Gated High-Pitch Mode and Retrospectively Electrocardiogram-Gated Mode for Dual-Source CT Coronary Angiography.

PubMed

Koplay, Mustafa; Celik, Mahmut; Avcı, Ahmet; Erdogan, Hasan; Demir, Kenan; Sivri, Mesut; Nayman, Alaaddin

2015-01-01

We aimed to report the image quality, relationship between heart rate and image quality, amount of contrast agent given to the patients and radiation doses in coronary CT angiography (CTA) obtained by using high-pitch prospectively ECG-gated "Flash Spiral" technique (method A) or retrospectively ECG-gated technique (method B) using 128×2-slice dual-source CT. A total of 110 patients who were evaluated with method A and method B technique with a 128×2-detector dual-source CT device were included in the study. Patients were divided into three groups based on their heart rates during the procedure, and a relationship between heart rate and image quality were evaluated. The relationship between heart rate, gender and radiation dose received by the patients was compared. A total of 1760 segments were evaluated in terms of image quality. Comparison of the relationship between heart rate and image quality revealed a significant difference between heart rate <60 beats/min group and >75 beats/min group whereas <60 beats/min and 60-75 beats/min groups did not differ significantly. The average effective dose for coronary CTA was calculated as 1.11 mSv (0.47-2.01 mSv) for method A and 8.22 mSv (2.19-12.88 mSv) for method B. Method A provided high quality images with doses as low as <1 mSv in selected patients who have low heart rates with a high negative predictive value to rule out coronary artery disease. Although method B increases the amount of effective dose, it provides high diagnostic quality images for patients who have a high heart rate and arrhythmia which makes it is difficult to obtain images.

An Enhanced Method to Estimate Heart Rate from Seismocardiography via Ensemble Averaging of Body Movements at Six Degrees of Freedom.

PubMed

Lee, Hyunwoo; Lee, Hana; Whang, Mincheol

2018-01-15

Continuous cardiac monitoring has been developed to evaluate cardiac activity outside of clinical environments due to the advancement of novel instruments. Seismocardiography (SCG) is one of the vital components that could develop such a monitoring system. Although SCG has been presented with a lower accuracy, this novel cardiac indicator has been steadily proposed over traditional methods such as electrocardiography (ECG). Thus, it is necessary to develop an enhanced method by combining the significant cardiac indicators. In this study, the six-axis signals of accelerometer and gyroscope were measured and integrated by the L2 normalization and multi-dimensional kineticardiography (MKCG) approaches, respectively. The waveforms of accelerometer and gyroscope were standardized and combined via ensemble averaging, and the heart rate was calculated from the dominant frequency. Thirty participants (15 females) were asked to stand or sit in relaxed and aroused conditions. Their SCG was measured during the task. As a result, proposed method showed higher accuracy than traditional SCG methods in all measurement conditions. The three main contributions are as follows: (1) the ensemble averaging enhanced heart rate estimation with the benefits of the six-axis signals; (2) the proposed method was compared with the previous SCG method that employs fewer-axis; and (3) the method was tested in various measurement conditions for a more practical application.

Heart rate measurement based on a time-lapse image.

PubMed

Takano, Chihiro; Ohta, Yuji

2007-10-01

Using a time-lapse image acquired from a CCD camera, we developed a non-contact and non-invasive device, which could measure both the respiratory and pulse rate simultaneously. The time-lapse image of a part of the subject's skin was consecutively captured, and the changes in the average image brightness of the region of interest (ROI) were measured for 30s. The brightness data were processed by a series of operations of interpolation as follows a first-order derivative, a low pass filter of 2 Hz, and a sixth-order auto-regressive (AR) spectral analysis. Fourteen sound and healthy female subjects (22-27 years of age) participated in the experiments. Each subject was told to keep a relaxed seating posture with no physical restriction. At the same time, heart rate was measured by a pulse oximeter and respiratory rate was measured by a thermistor placed at the external naris. Using AR spectral analysis, two clear peaks could be detected at approximately 0.3 and 1.2 Hz. The peaks were thought to correspond to the respiratory rate and the heart rate. Correlation coefficients of 0.90 and 0.93 were obtained for the measurement of heart rate and respiratory rate, respectively.

Cascade and parallel combination (CPC) of adaptive filters for estimating heart rate during intensive physical exercise from photoplethysmographic signal

PubMed Central

Islam, Mohammad Tariqul; Tanvir Ahmed, Sk.; Zabir, Ishmam; Shahnaz, Celia

2018-01-01

Photoplethysmographic (PPG) signal is getting popularity for monitoring heart rate in wearable devices because of simplicity of construction and low cost of the sensor. The task becomes very difficult due to the presence of various motion artefacts. In this study, an algorithm based on cascade and parallel combination (CPC) of adaptive filters is proposed in order to reduce the effect of motion artefacts. First, preliminary noise reduction is performed by averaging two channel PPG signals. Next in order to reduce the effect of motion artefacts, a cascaded filter structure consisting of three cascaded adaptive filter blocks is developed where three-channel accelerometer signals are used as references to motion artefacts. To further reduce the affect of noise, a scheme based on convex combination of two such cascaded adaptive noise cancelers is introduced, where two widely used adaptive filters namely recursive least squares and least mean squares filters are employed. Heart rates are estimated from the noise reduced PPG signal in spectral domain. Finally, an efficient heart rate tracking algorithm is designed based on the nature of the heart rate variability. The performance of the proposed CPC method is tested on a widely used public database. It is found that the proposed method offers very low estimation error and a smooth heart rate tracking with simple algorithmic approach. PMID:29515812

SVM-Based Spectral Analysis for Heart Rate from Multi-Channel WPPG Sensor Signals.

PubMed

Xiong, Jiping; Cai, Lisang; Wang, Fei; He, Xiaowei

2017-03-03

Although wrist-type photoplethysmographic (hereafter referred to as WPPG) sensor signals can measure heart rate quite conveniently, the subjects' hand movements can cause strong motion artifacts, and then the motion artifacts will heavily contaminate WPPG signals. Hence, it is challenging for us to accurately estimate heart rate from WPPG signals during intense physical activities. The WWPG method has attracted more attention thanks to the popularity of wrist-worn wearable devices. In this paper, a mixed approach called Mix-SVM is proposed, it can use multi-channel WPPG sensor signals and simultaneous acceleration signals to measurement heart rate. Firstly, we combine the principle component analysis and adaptive filter to remove a part of the motion artifacts. Due to the strong relativity between motion artifacts and acceleration signals, the further denoising problem is regarded as a sparse signals reconstruction problem. Then, we use a spectrum subtraction method to eliminate motion artifacts effectively. Finally, the spectral peak corresponding to heart rate is sought by an SVM-based spectral analysis method. Through the public PPG database in the 2015 IEEE Signal Processing Cup, we acquire the experimental results, i.e., the average absolute error was 1.01 beat per minute, and the Pearson correlation was 0.9972. These results also confirm that the proposed Mix-SVM approach has potential for multi-channel WPPG-based heart rate estimation in the presence of intense physical exercise.

Heartbeat detection in multimodal physiological signals using signal quality assessment based on sample entropy.

PubMed

Singh, Omkar; Sunkaria, Ramesh Kumar

2017-12-01

This paper presents a novel technique to identify heartbeats in multimodal data using electrocardiogram (ECG) and arterial blood pressure (ABP) signals. Multiple physiological signals such as ECG, ABP, and Respiration are often recorded in parallel from the activity of heart. These signals generally possess related information as they are generated by the same physical system. The ECG and ABP correspond to the same phenomenon of contraction and relaxation activity of heart. Multiple signals acquired from various sensors are generally processed independently, thus discarding the information from other measurements. In the estimation of heart rate and heart rate variability, the R peaks are generally identified from ECG signal. Efficient detection of R-peaks in electrocardiogram (ECG) is a key component in the estimation of clinically relevant parameters from ECG. However, when the signal is severely affected by undesired artifacts, this becomes a challenging task. Sometimes in clinical environment, other physiological signals reflecting the cardiac activity such as ABP signal are also acquired simultaneously. Under the availability of such multimodal signals, the accuracy of R peak detection methods can be improved using sensor-fusion techniques. In the proposed method, the sample entropy (SampEn) is used as a metric for assessing the noise content in the physiological signal and the R peaks in ECG and the systolic peaks in ABP signals are fused together to enhance the efficiency of heartbeat detection. The proposed method was evaluated on the 100 records from the computing in cardiology challenge 2014 training data set. The performance parameters are: sensitivity (Se) and positive predictivity (PPV). The unimodal R peaks detector achieved: Se gross = 99.40%, PPV gross = 99.29%, Se average = 99.37%, PPV average = 99.29%. Similarly unimodal BP delineator achieved Se gross = 99.93%, PPV gross = 99.99%, Se average = 99.93%, PPV average = 99.99% whereas, the proposed multimodal beat detector achieved: Se gross = 99.65%, PPV gross = 99.91%, Se average = 99.68%, PPV average = 99.91%.

Dynamic RSA: Examining parasympathetic regulatory dynamics via vector-autoregressive modeling of time-varying RSA and heart period.

PubMed

Fisher, Aaron J; Reeves, Jonathan W; Chi, Cyrus

2016-07-01

Expanding on recently published methods, the current study presents an approach to estimating the dynamic, regulatory effect of the parasympathetic nervous system on heart period on a moment-to-moment basis. We estimated second-to-second variation in respiratory sinus arrhythmia (RSA) in order to estimate the contemporaneous and time-lagged relationships among RSA, interbeat interval (IBI), and respiration rate via vector autoregression. Moreover, we modeled these relationships at lags of 1 s to 10 s, in order to evaluate the optimal latency for estimating dynamic RSA effects. The IBI (t) on RSA (t-n) regression parameter was extracted from individual models as an operationalization of the regulatory effect of RSA on IBI-referred to as dynamic RSA (dRSA). Dynamic RSA positively correlated with standard averages of heart rate and negatively correlated with standard averages of RSA. We propose that dRSA reflects the active downregulation of heart period by the parasympathetic nervous system and thus represents a novel metric that provides incremental validity in the measurement of autonomic cardiac control-specifically, a method by which parasympathetic regulatory effects can be measured in process. © 2016 Society for Psychophysiological Research.

[Mortality from heart attack in Belgrade population during the period 1990-2004].

PubMed

Ratkov, Isidora; Sipetić, Sandra; Vlajinac, Hristina; Sekeres, Bojan

2008-01-01

In most countries, cardiovascular diseases are the leading disorders, with ischemic heart diseases being the leading cause of death. According to WHO data, every year about 17 million people die of cardiovascular diseases, which is 30% of all deaths. Ischemic heart diseases contribute from one-third to one-half of all deaths due to cardiovascular diseases. Three point eight million men and 3.4 million women in the world die every year from ischemic heart diseases, and in Europe about 2 million. The highest mortality rate from ischemic heart diseases occurs in India, China and Russia. The aim of this descriptive epidemiological study was to determine heart attack mortality in Belgrade population during the period 1990-2004. In the study, we conducted investigation of Belgrade population during the period 1990-2004. Mortality data were obtained from the city institution for statistics. The mortality rates were calculated based on the total Belgrade population obtained from the mean values for the last two register years (1991 and 2002). The mortality rates were standardized using the direct method of standardization according to the world (Segi) standard population. In the Belgrade population during the period 1990-2004, the participation of mortality rate due to heart attack among deaths from cardiovascular diseases was 17% in males and 10% in females. In Belgrade male population, mean standardized mortality rates (per 100,000 habitants) were 50.5 for heart attack, 8.3 for chronic ischemic heart diseases and 4.6 for angina pectoris, while in females the rates were 30.8, 6.7 and 4.2, respectively. Mortality from ischemic heart diseases and from heart attack was higher in males than in females. During the studied 15-year period, on average 755 males and 483 females died due to heart attack every year. Mean standardized mortality rates per 100,000 habitants were 50.0 in male and 31.1 in female population. Males died 1.6 times more frequently from heart attack than females. During the studied period, mean standardized mortality rates from heart attack, in the population aged over 30 increased with age both in male and female population. However, males tended to die from heart attack at an earlier age than females, with death rates for males approximately the same as those for women who were 10 years older. In Belgrade during the period from 1990-2004, we found that there was an increasing trend in mortality rate due to cardiovascular diseases, while the trend of mortality rate from heart attack was constant with insignificant oscillations.

Assessment of cardiotoxicity and effects of malathion on the early development of zebrafish (Danio rerio) using computer vision for heart rate quantification.

PubMed

Simoneschi, Daniele; Simoneschi, Francesco; Todd, Nancy E

2014-06-01

Malathion, a common organophosphate insecticide, is a proven acetylcholinesterase inhibitor and is the most applied organophosphate insecticide in the United States. The use of zebrafish as a model to study the effects of pesticides on development is an innovative approach yielding relevant implications for determining the potential toxic effects of these pesticides on humans. In this study, a simple noninvasive technique was developed to investigate the cardiotoxicity of malathion on Danio rerio embryos, and to detect and quantify its effect on heart rate. Videos were recorded under a stereomicroscope and examined with our custom-made software (FishBeat) to determine the heart rate of the embryos. The pixel average intensity frequency (PI) of the videos was computed at its maximum probability to indicate the average number of heartbeats per second. Experimental observations successfully demonstrated that this method was able to detect the heart rate of zebrafish embryos as compared with manual stopwatch counting, with no significant difference. Embryos were treated acutely with increasing malathion concentrations (33.3 and 50 μg/mL malathion) at 52, 76, and 96 hpf. Embryos treated with 33.3 μg/mL malathion had significant bradycardia at 52 and 76 hpf, whereas embryos treated with 50 μg/mL malathion presented bradycardia at all hpf. These novel observations confirmed that malathion, acting as an acetylcholinesterase inhibitor, induced heartbeat irregularity in zebrafish embryos.

Effects of simulated increased gravity on the rate of aging of rats - Implications for the rate of living theory of aging

NASA Technical Reports Server (NTRS)

Economos, A. C.; Ballard, R. C.; Blunden, M.; Miquel, J.; Lindseth, K. A.; Fleming, J.; Philpott, D. E.; Oyama, J.

1982-01-01

It was found that the rate of aging of 17 month old rats which had been exposed to 3.14 times normal gravity in an animal centrifuge for 8 months was larger than that of the controls as determined by the apparently elevated lipofuscin content in heart and kidney, reduced numbers and increased size of mitochondria of heart tissue, and inferior liver mitochondria respiration. Steady-state food intake per day per kg body weight, which is presumably proportional to rate of living or specific basal metabolic expenditure, was found to be about 18 percent higher than in the controls after an initial 2 month adaptation period. Although half of the centrifuged animals lived only a little shorter than the controls (average about 343 vs. 364 days on the average, statistically nonsignificant), the remaining half (longest survivors) lived on the centrifuge an average of 520 days (range 483-572) compared to an average of 574 days (range 502-615) for the controls, computed from the onset of centrifugation, or 11 percent shorter. These findings indicate that a moderate increase of the level of basal metabolism of young adult rats adapted to hypergravity compared to controls in normal gravity is accompanied by a roughly similar increase in the rate of organ aging and reduction of survival, in agreement with Pearl's (1928) rate of living theory of aging, previously experimentally demonstrated only in poikilotherms.

Conversion of cardiac performance data in analog form for digital computer entry

NASA Technical Reports Server (NTRS)

Miller, R. L.

1972-01-01

A system is presented which will reduce analog cardiac performance data and convert the results to digital form for direct entry into a commercial time-shared computer. Circuits are discussed which perform the measurement and digital conversion of instantaneous systolic and diastolic parameters from the analog blood pressure waveform. Digital averaging over a selected number of heart cycles is performed on these measurements, as well as those of flow and heart rate. The determination of average cardiac output and peripheral resistance, including trends, is the end result after processing by digital computer.

Long-Term Coarse Particulate Matter Exposure and Heart Rate Variability in the Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Adhikari, Richa; D’Souza, Jennifer; Solimon, Elsayed Z.; Burke, Gregory L.; Daviglus, Martha; Jacobs, David R.; Park, Sung Kyun; Sheppard, Lianne; Thorne, Peter S.; Kaufman, Joel D.; Larson, Timothy V.; Adar, Sara D.

2017-01-01

Background Reduced heart rate variability, a marker of impaired cardiac autonomic function, has been linked to short-term exposure to airborne particles. This research adds to the literature by examining associations with long-term exposures to coarse particles (PM10-2.5). Methods Using electrocardiogram recordings from 2,780 participants (45-84 years) from three Multi-Ethnic Study of Atherosclerosis sites, we assessed the standard deviation of normal-to-normal intervals (SDNN) and root-mean square differences of successive normal-to-normal intervals (rMSSD) at a baseline (2000-2002) and follow-up (2010-2012) examination (mean visits/person=1.5). Annual average concentrations of PM10-2.5 mass, copper, zinc, phosphorus, silicon, and endotoxin were estimated using site-specific spatial prediction models. We assessed associations for baseline heart rate variability and rate of change in heart rate variability over time using multivariable mixed models adjusted for time, sociodemographic, lifestyle, health, and neighborhood confounders, including co-pollutants. Results In our primary models adjusted for demographic and lifestyle factors and site, PM10-2.5 mass was associated with 1.0% (95% CI: -4.1, 2.1%) lower SDNN levels per interquartile range of 2 μg/m3. Stronger associations, however, were observed prior to site adjustment and with increasing residential stablity. Similar patterns were found for rMSSD. We found little evidence for associations with other chemical species and with with the rate of change in heart rate variability, though endotoxin was associated with increasing heart rate variability over time. Conclusion We found only weak evidence that long-term PM10-2.5 exposures are associated with lowered heart rate variability. Stronger associations among residentially stable individuals suggest that confirmatory studies are needed. PMID:27035690

Phasic changes in human right coronary blood flow before and after repair of aortic insufficiency.

PubMed

Folts, J D; Rowe, G G; Kahn, D R; Young, W P

1979-02-01

We have shown previously that acute aortic insufficiency in chronically instrumented dogs reverses the normally high ratio of diastolic to systolic coronary blood flow. Phasic blood flow in the dominant right coronary artery was measured directly with an electromagnetic flow meter during surgery in eight patients with severe aortic insufficiency before and after relacement of the aortic valve. Before the insufficiency was eliminated, right coronary flow average 116 +/- 37 ml./minute and the diastolic to systolic flow ratio was 0.88 +/- 17. Mean arterial blood pressure averaged 106 +/- 17 mm. Hg, heart rate 84 +/- 19 beats/minute, and mean diastolic pressure averaged 67 +/- 10 mm. Hg. After the aortic valve was replaced with an average heart rate of 90 +/- 15 and mean blood pressure of 103 +/- 13 mm. Hg, the average right coronary blood flow increased to 180 +/- 40 ml./minute with a D/S ratio of 2.18 +/- 0.8. In all cases the right coronary blood flow increased after the aortic insufficiency was eliminated surgically. Right coronary flow probably increased because of the improved diastolic perfusion pressure and the change from predominantly systolic to diastolic coronary flow.

Signal loss during fetal heart rate monitoring using maternal abdominal surface electrodes between 28 and 42 weeks of pregnancy.

PubMed

Fuchs, Tomasz; Pomorski, Michał; Grobelak, Krzysztof; Tomiałowicz, Marek; Zimmer, Mariusz

2014-01-01

Fetal electrocardiography is one of the methods for monitoring the well-being of the fetus. Signal loss limits the proper interpretation of electrocardiogram traces. The aim of this study was to assess the average signal loss in non-invasive abdominal fetal electrocardiogram (fECG) monitoring using the KOMPOREL fetal monitoring system (ITAM, Zabrze, Poland) in women between 28 and 42 week of pregnancy. The results were compared to FIGO (International Federation of Gynaecology and Obstetric) and DGGG (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe e.V.) recommendations concerning fetal heart monitoring. The correlation between fetal ECG signal quality, week of pregnancy and patient BMI was evaluated. 773 pregnant women, hospitalized and diagnosed in the Department of Gynecology and Obstetrics, Wroclaw Medical University, underwent 30 min of abdominal fECG recordings using the KOMPOREL fetal monitoring system. The average signal loss in abdominal fECG monitoring in the study group was 32%. FIGO recommendations describe an acceptable fetal signal loss of 20%. In our study, 46% (357/773) of the recordings were up to FIGO standards, with fetal heart rate success rates above 80%. According to DGGG guidelines, with acceptable fetal signal loss of 15%, only 39% (303/773) of the recordings could be assessed as accurate. No correlation between fECG signal quality, week of pregnancy and patient BMI was proved. The average signal loss in abdominal fECG monitoring in our study group was 32%. Low fECG signal quality may constitute a potentially limiting factor of the described fetal heart monitoring system. No relationship between fECG signal quality, week of pregnancy and patient BMI was proved.

Primary Blast Injury Criteria for Animal/Human TBI Models using Field Validated Shock Tubes

DTIC Science & Technology

2016-09-01

Software, Inc., San Jose, CA). Dose-response models for heart rate and pulmonary injury were fitted with Origin 9.0 software (OriginLab Corp...impulse. We observed only a few cases where pathological score exceeded 21 for the blast 7 strength higher than 300 kPa BOP with high standard...average heart rates (ΔHR) decreased gradually with increase in blast intensity: -29±10 (60 kPa), - 26±20 (100 kPa), -43±26 (130 kPa), -62±21 (190

Non-contact and noise tolerant heart rate monitoring using microwave doppler sensor and range imagery.

PubMed

Matsunag, Daichi; Izumi, Shintaro; Okuno, Keisuke; Kawaguchi, Hiroshi; Yoshimoto, Masahiko

2015-01-01

This paper describes a non-contact and noise-tolerant heart beat monitoring system. The proposed system comprises a microwave Doppler sensor and range imagery using Microsoft Kinect™. The possible application of the proposed system is a driver health monitoring. We introduce the sensor fusion approach to minimize the heart beat detection error. The proposed algorithm can subtract a body motion artifact from Doppler sensor output using time-frequency analysis. The body motion artifact is a crucially important problem for biosignal monitoring using microwave Doppler sensor. The body motion speed is obtainable from range imagery, which has 5-mm resolution at 30-cm distance. Measurement results show that the success rate of the heart beat detection is improved about 75% on average when the Doppler wave is degraded by the body motion artifact.

A real-time approach for heart rate monitoring using a Hilbert transform in seismocardiograms.

PubMed

Jafari Tadi, Mojtaba; Lehtonen, Eero; Hurnanen, Tero; Koskinen, Juho; Eriksson, Jonas; Pänkäälä, Mikko; Teräs, Mika; Koivisto, Tero

2016-11-01

Heart rate monitoring helps in assessing the functionality and condition of the cardiovascular system. We present a new real-time applicable approach for estimating beat-to-beat time intervals and heart rate in seismocardiograms acquired from a tri-axial microelectromechanical accelerometer. Seismocardiography (SCG) is a non-invasive method for heart monitoring which measures the mechanical activity of the heart. Measuring true beat-to-beat time intervals from SCG could be used for monitoring of the heart rhythm, for heart rate variability analysis and for many other clinical applications. In this paper we present the Hilbert adaptive beat identification technique for the detection of heartbeat timings and inter-beat time intervals in SCG from healthy volunteers in three different positions, i.e. supine, left and right recumbent. Our method is electrocardiogram (ECG) independent, as it does not require any ECG fiducial points to estimate the beat-to-beat intervals. The performance of the algorithm was tested against standard ECG measurements. The average true positive rate, positive prediction value and detection error rate for the different positions were, respectively, supine (95.8%, 96.0% and ≃0.6%), left (99.3%, 98.8% and ≃0.001%) and right (99.53%, 99.3% and ≃0.01%). High correlation and agreement was observed between SCG and ECG inter-beat intervals (r  >  0.99) for all positions, which highlights the capability of the algorithm for SCG heart monitoring from different positions. Additionally, we demonstrate the applicability of the proposed method in smartphone based SCG. In conclusion, the proposed algorithm can be used for real-time continuous unobtrusive cardiac monitoring, smartphone cardiography, and in wearable devices aimed at health and well-being applications.

Competition model for aperiodic stochastic resonance in a Fitzhugh-Nagumo model of cardiac sensory neurons.

PubMed

Kember, G C; Fenton, G A; Armour, J A; Kalyaniwalla, N

2001-04-01

Regional cardiac control depends upon feedback of the status of the heart from afferent neurons responding to chemical and mechanical stimuli as transduced by an array of sensory neurites. Emerging experimental evidence shows that neural control in the heart may be partially exerted using subthreshold inputs that are amplified by noisy mechanical fluctuations. This amplification is known as aperiodic stochastic resonance (ASR). Neural control in the noisy, subthreshold regime is difficult to see since there is a near absence of any correlation between input and the output, the latter being the average firing (spiking) rate of the neuron. This lack of correlation is unresolved by traditional energy models of ASR since these models are unsuitable for identifying "cause and effect" between such inputs and outputs. In this paper, the "competition between averages" model is used to determine what portion of a noisy, subthreshold input is responsible, on average, for the output of sensory neurons as represented by the Fitzhugh-Nagumo equations. A physiologically relevant conclusion of this analysis is that a nearly constant amount of input is responsible for a spike, on average, and this amount is approximately independent of the firing rate. Hence, correlation measures are generally reduced as the firing rate is lowered even though neural control under this model is actually unaffected.

Decreased Variability of the 6-Minute Walk Test by Heart Rate Correction in Patients with Neuromuscular Disease

PubMed Central

Prahm, Kira P.; Witting, Nanna; Vissing, John

2014-01-01

Objective The 6-minute walk test is widely used to assess functional status in neurological disorders. However, the test is subject to great inter-test variability due to fluctuating motivation, fatigue and learning effects. We investigated whether inter-test variability of the 6MWT can be reduced by heart rate correction. Methods Sixteen patients with neuromuscular diseases, including Facioscapulohumeral muscular dystrophy, Limb-girdle muscular dystrophy, Charcot-Marie-Tooths, Dystrophia Myotonica and Congenital Myopathy and 12 healthy subjects were studied. Patients were excluded if they had cardiac arrhythmias, if they received drug treatment for hypertension or any other medical conditions that could interfere with the interpretation of the heart rate and walking capability. All completed three 6-minute walk tests on three different test-days. Heart rate was measured continuously. Results Successive standard 6-minute walk tests showed considerable learning effects between Tests 1 and 2 (4.9%; P = 0.026), and Tests 2 and 3 (4.5%; P = 0.020) in patients. The same was seen in controls between Tests 1 and 2 (8.1%; P = 0.039)). Heart rate correction abolished this learning effect. Conclusion A modified 6-minute walk test, by correcting walking distance with average heart rate during walking, decreases the variability among repeated 6-minute walk tests, and should be considered as an alternative outcome measure to the standard 6-minute walk test in future clinical follow-up and treatment trials. PMID:25479403

Relationships between QT interval and heart rate variability at rest and the covariates in healthy young adults.

PubMed

Arai, Kaori; Nakagawa, Yui; Iwata, Toyoto; Horiguchi, Hyogo; Murata, Katsuyuki

2013-01-01

To clarify the links between ECG QT-related parameters and heart rate variability (HRV) and the covariates possibly distorting them, the averaged RR and QT intervals in a single lead ECG were measured for 64 male and 86 female subjects aged 18-26. The QT index, defined by Rautaharju et al., in the young adults was not significantly related to any HRV parameters nor heart rate, but the Bazett's corrected QT (QTc) interval was associated negatively with the parasympathetic activity and positively with heart rate. No significant differences in the QTc interval, QT index or heart rate were seen between the men and women, but they significantly differed between both sexes after adjustment for possible covariates such as age and body mass index (BMI). Significant sex differences in parasympathetic parameters of the HRV were unchanged before and after the adjustment, but significant differences observed in the unadjusted sympathetic parameters disappeared after adjusting for covariates. Age, BMI and body fat percentage also were significant covariates affecting these ECG parameters. Consequently, QT index, unaffected by heart rate and HRV parameters, appears to be a more useful indicator than the QTc interval. Instead, the QT index and HRV parameters are recommended to be simultaneously measured in epidemiological research because they are probably complementary in assessing autonomic nervous function. Also, these parameters should be analyzed in men and women separately. Copyright © 2012 Elsevier B.V. All rights reserved.

Neonatal heart rate prediction.

PubMed

Abdel-Rahman, Yumna; Jeremic, Aleksander; Tan, Kenneth

2009-01-01

Technological advances have caused a decrease in the number of infant deaths. Pre-term infants now have a substantially increased chance of survival. One of the mechanisms that is vital to saving the lives of these infants is continuous monitoring and early diagnosis. With continuous monitoring huge amounts of data are collected with so much information embedded in them. By using statistical analysis this information can be extracted and used to aid diagnosis and to understand development. In this study we have a large dataset containing over 180 pre-term infants whose heart rates were recorded over the length of their stay in the Neonatal Intensive Care Unit (NICU). We test two types of models, empirical bayesian and autoregressive moving average. We then attempt to predict future values. The autoregressive moving average model showed better results but required more computation.

Assessment of professional baseball players aerobic exercise performance depending on their positions.

PubMed

Yang, Seung-Won

2014-11-01

This study reports the average and SD of professional baseball players' cardiorespiratory endurance, maximum oxygen consumption, oxygen consumption during anaerobic threshold, maximum oxygen consumption of anaerobic threshold %, maximum heart rate, and heart rate of anaerobic threshold. We also report the comparison between pitchers and fielders. Considering the total number of results, percentile was used and results were classified into 5 grades. One professional baseball players' organization with more than 14 years of experience participated in this study. First, we observed that the average pitchers' V[Combining Dot Above]O2max was 53.64 ml·kg·min, whereas the average fielders' was 52.30 ml·kg·min. These values were lower than other sports players. Second, in case of the V[Combining Dot Above]O2AT, pitchers showed 39.35 ml·kg·min and fielders showed 39.96 ml·kg·min. %V[Combining Dot Above]O2AT showed a significant difference of 71.13% between pitchers and fielders-pitchers, whereas fielders showed 73.89% (p < 0.01). Third, maximal heart rates were measured at 188.69 b·min (pitchers) and 187.79 b·min (fielders). These were lower than college baseball players and higher than other sports players. In conclusion, both professional baseball pitchers and fielders should be aware of the necessity of systematic cardiorespiratory endurance data analysis. Moreover, baseball teams, athletic trainers, and coaches should also be aware of the importance of cardiorespiratory endurance.

Clinical application of pulse transit time and correlation with intrapartum fetal heart rate monitoring: a preliminary study of 18 full-term infants.

PubMed

Kawagoe, Yasuyuki; Sameshima, Hiroshi; Ikenoue, Tsuyomu

2008-07-01

The authors show that pulse transit time and blood pressure are reciprocal in fetal goat models. They applied this technique in clinical settings to correlate changes in pulse transit time with fetal heart rate monitoring patterns and acid-base status. In 18 uncomplicated pregnancies, pulse transit time was obtained from electrocardiograms to pulse oximeter waveform and averaged during each baseline period, defined by the interpretation of fetal heart rate monitoring. According to a > 10% change from the control value, chronological changes were categorized into shortened, unchanged, and prolonged. Pulse transit time was available in 82% +/- 11% of the recordings. In 15 fetuses, 2 (13%) showed prolonged, 7 (47%) showed shortened, and 6 (40%) showed unchanged conditions. Comparisons of the shortened and unchanged categories revealed that severe variable deceleration was significantly increased, and half or more fetuses showed hypoxemia in the shortened category. Shortening of pulse transit time, theoretically indicating a hypertensive condition, was more frequently associated with severe variable decelerations, suggesting that the pulse transit time may supplement the interpretation of fetal heart rate monitoring.

A cross-sectional study of differences in 6-min walk distance in healthy adults residing at high altitude versus sea level

PubMed Central

2014-01-01

Background We sought to determine if adult residents living at high altitude have developed sufficient adaptation to a hypoxic environment to match the functional capacity of a similar population at sea level. To test this hypothesis, we compared the 6-min walk test distance (6MWD) in 334 residents living at sea level vs. at high altitude. Methods We enrolled 168 healthy adults aged ≥35 years residing at sea level in Lima and 166 individuals residing at 3,825 m above sea level in Puno, Peru. Participants completed a 6-min walk test, answered a sociodemographics and clinical questionnaire, underwent spirometry, and a blood test. Results Average age was 54.0 vs. 53.8 years, 48% vs. 43% were male, average height was 155 vs. 158 cm, average blood oxygen saturation was 98% vs. 90%, and average resting heart rate was 67 vs. 72 beats/min in Lima vs. Puno. In multivariable regression, participants in Puno walked 47.6 m less (95% CI -81.7 to -13.6 m; p < 0.01) than those in Lima. Other variables besides age and height that were associated with 6MWD include change in heart rate (4.0 m per beats/min increase above resting heart rate; p < 0.001) and percent body fat (-1.4 m per % increase; p = 0.02). Conclusions The 6-min walk test predicted a lowered functional capacity among Andean high altitude vs. sea level natives at their altitude of residence, which could be explained by an incomplete adaptation or a protective mechanism favoring neuro- and cardioprotection over psychomotor activity. PMID:24484777

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed Central

El-Amrawy, Fatema

2015-01-01

Objectives The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Methods Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. Results The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. Conclusions The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure. PMID:26618039

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed

El-Amrawy, Fatema; Nounou, Mohamed Ismail

2015-10-01

The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure.

Repeated change-of-direction test for collegiate male soccer players.

PubMed

Mizuguchi, S; Gray, H; Calabrese, L S; Haff, G G; Sands, W A; Ramsey, M W; Cardinale, M; Stone, M H

2014-08-01

The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test's ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.

Detecting drug-induced prolongation of the QRS complex: New insights for cardiac safety assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cros, C., E-mail: caroline.cros@hotmail.co.uk; Skinner, M., E-mail: Matthew.Skinner@astrazeneca.com; Moors, J.

Background: Drugs slowing the conduction of the cardiac action potential and prolonging QRS complex duration by blocking the sodium current (I{sub Na}) may carry pro-arrhythmic risks. Due to the frequency-dependent block of I{sub Na}, this study assesses whether activity-related spontaneous increases in heart rate (HR) occurring during standard dog telemetry studies can be used to optimise the detection of class I antiarrhythmic-induced QRS prolongation. Methods: Telemetered dogs were orally dosed with quinidine (class Ia), mexiletine (class Ib) or flecainide (class Ic). QRS duration was determined standardly (5 beats averaged at rest) but also prior to and at the plateau ofmore » each acute increase in HR (3 beats averaged at steady state), and averaged over 1 h period from 1 h pre-dose to 5 h post-dose. Results: Compared to time-matched vehicle, at rest, only quinidine and flecainide induced increases in QRS duration (E{sub max} 13% and 20% respectively, P < 0.01–0.001) whereas mexiletine had no effect. Importantly, the increase in QRS duration was enhanced at peak HR with an additional effect of + 0.7 ± 0.5 ms (quinidine, NS), + 1.8 ± 0.8 ms (mexiletine, P < 0.05) and + 2.8 ± 0.8 ms (flecainide, P < 0.01) (calculated as QRS at basal HR-QRS at high HR). Conclusion: Electrocardiogram recordings during elevated HR, not considered during routine analysis optimised for detecting QT prolongation, can be used to sensitise the detection of QRS prolongation. This could prove useful when borderline QRS effects are detected. Analysing during acute increases in HR could also be useful for detecting drug-induced effects on other aspects of cardiac function. -- Highlights: ► We aimed to improve detection of drug-induced QRS prolongation in safety screening. ► We used telemetered dogs to test class I antiarrhythmics at low and high heart rate. ► At low heart rate only quinidine and flecainide induced an increase in QRS duration. ► At high heart rate the effects of two out of three antiarrhythmics were enhanced. ► Detection of a drug-induced prolongation of QRS was improved at high heart rate.« less

Effects of concurrent physical and cognitive demands on muscle activity and heart rate variability in a repetitive upper-extremity precision task.

PubMed

Srinivasan, Divya; Mathiassen, Svend Erik; Hallman, David M; Samani, Afshin; Madeleine, Pascal; Lyskov, Eugene

2016-01-01

Most previous studies of concurrent physical and cognitive demands have addressed tasks of limited relevance to occupational work, and with dissociated physical and cognitive task components. This study investigated effects on muscle activity and heart rate variability of executing a repetitive occupational task with an added cognitive demand integral to correct task performance. Thirty-five healthy females performed 7.5 min of standardized repetitive pipetting work in a baseline condition and a concurrent cognitive condition involving a complex instruction for correct performance. Average levels and variabilities of electromyographic activities in the upper trapezius and extensor carpi radialis (ECR) muscles were compared between these two conditions. Heart rate and heart rate variability were also assessed to measure autonomic nervous system activation. Subjects also rated perceived fatigue in the neck-shoulder region, as well as exertion. Concurrent cognitive demands increased trapezius muscle activity from 8.2% of maximum voluntary exertion (MVE) in baseline to 9.0% MVE (p = 0.0005), but did not significantly affect ECR muscle activity, heart rate, heart rate variability, perceived fatigue or exertion. Trapezius muscle activity increased by about 10%, without any accompanying cardiovascular response to indicate increased sympathetic activation. We suggest this slight increase in trapezius muscle activity to be due to changed muscle activation patterns within or among shoulder muscles. The results suggest that it may be possible to introduce modest cognitive demands necessary for correct performance in repetitive precision work without any major physiological effects, at least in the short term.

Combined effect of whole-body vibration and ambient lighting on human discomfort, heart rate, and reaction time.

PubMed

Monazzam, Mohammad Reza; Shoja, Esmaeil; Zakerian, Seyed Abolfazl; Foroushani, Abbas Rahimi; Shoja, Mohsen; Gharaee, Masoumeh; Asgari, Amin

2018-07-01

This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.

[Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

PubMed

Zhao, Jing; He, Fei; Hu, Da-yi; Ding, Rong-jing; Yu, Xiao-jun; Wang, Long; Zhang, Ping; Li, Xue-bin; Guo, Ji-hong; Liu, Wen-ling; Li, Cui-lan; Li, Lei; Gao, Chuan-yu; Zhao, Luo-sha; Chu, Ying-jie; Huang, Zhen-wen; Wei, Jing-han; Hua, Shao-hua; Liu, Rui-yun; Zhuang, Xiao-feng

2013-05-01

To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P < 0.01). (3) Heart rate and diastolic blood pressure were significantly higher in passive smoking group than in control group (all P < 0.05) while systolic blood pressure was similar between the 2 groups (P > 0.05). Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.

Recurrence Plots: a New Tool for Quantification of Cardiac Autonomic Nervous System Recovery after Transplant.

PubMed

Takakura, Isabela Thomaz; Hoshi, Rosangela Akemi; Santos, Márcio Antonio; Pivatelli, Flávio Correa; Nóbrega, João Honorato; Guedes, Débora Linhares; Nogueira, Victor Freire; Frota, Tuane Queiroz; Castelo, Gabriel Castro; Godoy, Moacir Fernandes de

2017-01-01

To evaluate a possible evolutionary post-heart transplant return of autonomic function using quantitative and qualitative information from recurrence plots. Using electrocardiography, 102 RR tachograms of 45 patients (64.4% male) who underwent heart transplantation and that were available in the database were analyzed at different follow-up periods. The RR tachograms were collected from patients in the supine position for about 20 minutes. A time series with 1000 RR intervals was analyzed, a recurrence plot was created, and the following quantitative variables were evaluated: percentage of determinism, percentage of recurrence, average diagonal length, Shannon entropy, and sample entropy, as well as the visual qualitative aspect. Quantitative and qualitative signs of heart rate variability recovery were observed after transplantation. There is evidence that autonomic innervation of the heart begins to happen gradually after transplantation. Quantitative and qualitative analyses of recurrence can be useful tools for monitoring cardiac transplant patients and detecting the gradual return of heart rate variability.

Heterogeneity in horse ferritins. A comparative study of surface charge, iron content and kinetics of iron uptake.

PubMed Central

Russell, S M; Harrison, P M

1978-01-01

Horse ferritins from different organs show heterogeneity on electrofocusing in Ampholine gradients. Both ferritin and apoferritin from liver and spleen could be fractionated with respect to surface charge by serial precipitation with (NH4)2SO4. In the ferritin fractions, increasing iron content parallels increasing isoelectric point. After removal of their iron, those fractions which originally contained most iron accumulated added iron at the fastest rates. When unfractionated ferritins from different organs were compared the average isoelectric point increased in order spleen less than liver less than kidney less than heart. The order of initial rates of iron uptake by the apoferritins was spleen greater than kidney greater than heart and initial average iron contents also followed this order. The relatively low rates of iron accumulation by iron-poor molecules may have been due to structural alteration, to degradation, to activation of the iron-rich molecules or to other factors. Images Fig. 1. Fig. 2. PMID:736908

A pilot randomized controlled trial of EKG for neonatal resuscitation

PubMed Central

Katheria, Anup; Arnell, Kathy; Brown, Melissa; Hassen, Kasim; Maldonado, Mauricio; Finer, Neil

2017-01-01

Background The seventh edition of the American Academy of Pediatrics Neonatal Resuscitation Program recommends the use of a cardiac monitor in infants that need resuscitation. Previous trials have shown that EKG heart rate is available before pulse rate from a pulse oximeter. To date no trial has looked at how the availability of electrocardiogram (EKG) affects clinical interventions in the delivery room. Objective To determine whether the availability of an EKG heart rate value and tracing to the clinical team has an effect on physiologic measures and related interventions during the stabilization of preterm infants. Design/Methods Forty (40) premature infants enrolled in a neuro-monitoring study (The Neu-Prem Trial: NCT02605733) who had an EKG monitor available were randomized to have the heart rate information from the bedside EKG monitor either displayed or not displayed to the clinical team. Heart rate, oxygen saturation, FiO2 and mean airway pressure from a data acquisition system were recorded every 2 seconds. Results were averaged over 30 seconds and the differences analyzed using two-tailed t-test. Interventions analyzed included time to first change in FiO2, first positive pressure ventilation, first increase in airway pressure, and first intubation. Results There were no significant differences in time to clinical interventions between the blinded and unblinded group, despite the unblinded group having access to a visible heart rate at 66 +/- 20 compared to 114 +/- 39 seconds for the blinded group (p < .0001). Pulse rate from oximeter was lower than EKG heart rate during the first 2 minutes of life, but this was not significant. Conclusion(s) EKG provides an earlier, and more accurate heart rate than pulse rate from an oximeter during stabilization of preterm infants, allowing earlier intervention. All interventions were started earlier in the unblinded EKG group but these numbers were not significant in this small trial. Earlier EKG placement before pulse oximeter placement may affect other interventions, but this needs further study. PMID:29099872

Real-time heart rate measurement for multi-people using compressive tracking

NASA Astrophysics Data System (ADS)

Liu, Lingling; Zhao, Yuejin; Liu, Ming; Kong, Lingqin; Dong, Liquan; Ma, Feilong; Pang, Zongguang; Cai, Zhi; Zhang, Yachu; Hua, Peng; Yuan, Ruifeng

2017-09-01

The rise of aging population has created a demand for inexpensive, unobtrusive, automated health care solutions. Image PhotoPlethysmoGraphy(IPPG) aids in the development of these solutions by allowing for the extraction of physiological signals from video data. However, the main deficiencies of the recent IPPG methods are non-automated, non-real-time and susceptible to motion artifacts(MA). In this paper, a real-time heart rate(HR) detection method for multiple subjects simultaneously was proposed and realized using the open computer vision(openCV) library, which consists of getting multiple subjects' facial video automatically through a Webcam, detecting the region of interest (ROI) in the video, reducing the false detection rate by our improved Adaboost algorithm, reducing the MA by our improved compress tracking(CT) algorithm, wavelet noise-suppression algorithm for denoising and multi-threads for higher detection speed. For comparison, HR was measured simultaneously using a medical pulse oximetry device for every subject during all sessions. Experimental results on a data set of 30 subjects show that the max average absolute error of heart rate estimation is less than 8 beats per minute (BPM), and the processing speed of every frame has almost reached real-time: the experiments with video recordings of ten subjects under the condition of the pixel resolution of 600× 800 pixels show that the average HR detection time of 10 subjects was about 17 frames per second (fps).

Left ventricular approach for recording His bundle potential in man.

PubMed

Lee, Y S; Lien, W P

1975-06-01

The electrical potentials of the His bundle (HB) were recorded from the left ventricular endocardial surface in 28 patients ranging from 16 to 63 years of age. In 14 of the patients the left bundle branch (LB) potentials were also obtained. Placement of a bipolar electrode catheter tip toward the interventricular septum, right at and also 1 to 2 cm below the aortic valve, resulted in stable recordings of both potentials in successive cardiac cycles even at performing atrial or HB pacing from the right heart. The following intervals were measured in milliseconds (msec): P-A, A-H, H, H-V, LB, and LB-V. The average values in 12 patients (average age 26 plus or minus 7 years and average heart rate 90 plus or minus 16 beats per minute) with normal A-V conduction were as follows: P-A 28 plus or minus 7, A-H 76 plus or minus 16, H 19 plus or minus 3 and H-V 45 plus or minus 6 msec. The average values for LB and LB-V in 10 of these 12 patients were 15 plus or minus 3 and 25 plus or minus 3 msec respectively. Validation of the His bundle electrogram (HBE) from the left ventricular endocardial surface was based on simultaneous recordings of the intracardiac electrograms from both left and right sides of the heart in 18 patients. The individual average values for the intervals obtained from both sides of the heart in these patients were statistically not different, except that the H potential was slightly longer in duration fr m the left heart (P equals 0.05). Among these, 16 showed simultaneous onset of the H potentials, and the LB-V and RB-V conduction times from comparable points were almost the same. Indications for the left sided electro-physiologic studies include the following situations: (a) inability to record H from the right of the heart; (b) giant right atrium; and (c) possibly during atrial fibrillation.

Short-term heart rate variability in dogs with sick sinus syndrome or chronic mitral valve disease as compared to healthy controls.

PubMed

Bogucki, Sz; Noszczyk-Nowak, A

2017-03-28

Heart rate variability is an established risk factor for mortality in both healthy dogs and animals with heart failure. The aim of this study was to compare short-term heart rate variability (ST-HRV) parameters from 60-min electrocardiograms in dogs with sick sinus syndrome (SSS, n=20) or chronic mitral valve disease (CMVD, n=20) and healthy controls (n=50), and to verify the clinical application of ST-HRV analysis. The study groups differed significantly in terms of both time - and frequency- domain ST-HRV parameters. In the case of dogs with SSS and healthy controls, particularly evident differences pertained to HRV parameters linked directly to the variability of R-R intervals. Lower values of standard deviation of all R-R intervals (SDNN), standard deviation of the averaged R-R intervals for all 5-min segments (SDANN), mean of the standard deviations of all R-R intervals for all 5-min segments (SDNNI) and percentage of successive R-R intervals >50 ms (pNN50) corresponded to a decrease in parasympathetic regulation of heart rate in dogs with CMVD. These findings imply that ST-HRV may be useful for the identification of dogs with SSS and for detection of dysautonomia in animals with CMVD.

Heart rate, rate-pressure product, and oxygen uptake during four sexual activities.

PubMed

Bohlen, J G; Held, J P; Sanderson, M O; Patterson, R P

1984-09-01

Heart rate, rate-pressure product, and VO2 were measured in ten healthy men during four specified sexual activities: coitus with husband on top, coitus with wife on top, noncoital stimulation of husband by wife, and self-stimulation by husband. Foreplay generated slight, but statistically significant, increases above resting baseline in cardiac and metabolic variables. From stimulation through orgasm, average effort was modest for relatively short spans. Maximum exercise values occurred during the brief spans of orgasm, then returned quickly to near baseline levels. The two noncoital activities required lower expenditures than the two coital positions, with man-on-top coitus rating the highest. Large variations among subjects and among activities discourage use of a general equivalent activity for comparison, such as "two flights of stairs," to represent "sexual activity."

Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers

PubMed Central

Burns, Katrina N.; Sun, Kan; Fobil, Julius N.; Neitzel, Richard L.

2016-01-01

Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage. PMID:26797626

Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.

PubMed

Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L

2016-01-19

Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people's livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen's Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman's ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia.

PubMed

Clark, Steven L; Hamilton, Emily F; Garite, Thomas J; Timmins, Audra; Warrick, Philip A; Smith, Samuel

2017-02-01

Despite intensive efforts directed at initial training in fetal heart rate interpretation, continuing medical education, board certification/recertification, team training, and the development of specific protocols for the management of abnormal fetal heart rate patterns, the goals of consistently preventing hypoxia-induced fetal metabolic acidemia and neurologic injury remain elusive. The purpose of this study was to validate a recently published algorithm for the management of category II fetal heart rate tracings, to examine reasons for the birth of infants with significant metabolic acidemia despite the use of electronic fetal heart rate monitoring, and to examine critically the limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic acidemia. The potential performance of electronic fetal heart rate monitoring under ideal circumstances was evaluated in an outcomes-blinded examination fetal heart rate tracing of infants with metabolic acidemia at birth (base deficit, >12) and matched control infants (base deficit, <8) under the following conditions: (1) expert primary interpretation, (2) use of a published algorithm that was developed and endorsed by a large group of national experts, (3) assumption of a 30-minute period of evaluation for noncritical category II fetal heart rate tracings, followed by delivery within 30 minutes, (4) evaluation without the need to provide patient care simultaneously, and (5) comparison of results under these circumstances with those achieved in actual clinical practice. During the study period, 120 infants were identified with an arterial cord blood base deficit of >12 mM/L. Matched control infants were not demographically different from subjects. In actual practice, operative intervention on the basis of an abnormal fetal heart rate tracings occurred in 36 of 120 fetuses (30.0%) with metabolic acidemia. Based on expert, algorithm-assisted reviews, 55 of 120 patients with acidemia (45.8%) were judged to need operative intervention for abnormal fetal heart rate tracings. This difference was significant (P=.016). In infants who were born with a base deficit of >12 mM/L in which blinded, algorithm-assisted expert review indicated the need for operative delivery, the decision for delivery would have been made an average of 131 minutes before the actual delivery. The rate of expert intervention for fetal heart rate concerns in the nonacidemic control group (22/120; 18.3%) was similar to the actual intervention rate (23/120; 19.2%; P=1.0) Expert review did not mandate earlier delivery in 65 of 120 patients with metabolic acidemia. The primary features of these 65 cases included the occurrence of sentinel events with prolonged deceleration just before delivery, the rapid deterioration of nonemergent category II fetal heart rate tracings before realistic time frames for recognition and intervention, and the failure of recognized fetal heart rate patterns such as variability to identify metabolic acidemia. Expert, algorithm-assisted fetal heart rate interpretation has the potential to improve standard clinical performance by facilitating significantly earlier recognition of some tracings that are associated with metabolic acidemia without increasing the rate of operative intervention. However, this improvement is modest. Of infants who are born with metabolic acidemia, only approximately one-half potentially could be identified and have delivery expedited even under ideal circumstances, which are probably not realistic in current US practice. This represents the limits of electronic fetal heart rate monitoring performance. Additional technologies will be necessary if the goal of the prevention of neonatal metabolic acidemia is to be realized. Copyright © 2016 Elsevier Inc. All rights reserved.

Feasibility of Using a Smartwatch to Intensively Monitor Patients With Chronic Obstructive Pulmonary Disease: Prospective Cohort Study.

PubMed

Wu, Robert; Liaqat, Daniyal; de Lara, Eyal; Son, Tatiana; Rudzicz, Frank; Alshaer, Hisham; Abed-Esfahani, Pegah; Gershon, Andrea S

2018-06-14

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are associated with accelerated decline in lung function, diminished quality of life, and higher mortality. Proactively monitoring patients for early signs of an exacerbation and treating them early could prevent these outcomes. The emergence of affordable wearable technology allows for nearly continuous monitoring of heart rate and physical activity as well as recording of audio which can detect features such as coughing. These signals may be able to be used with predictive analytics to detect early exacerbations. Prior to full development, however, it is important to determine the feasibility of using wearable devices such as smartwatches to intensively monitor patients with COPD. We conducted a feasibility study to determine if patients with COPD would wear and maintain a smartwatch consistently and whether they would reliably collect and transmit sensor data. Patients with COPD were recruited from 3 hospitals and were provided with a smartwatch that recorded audio, heart rate, and accelerations. They were asked to wear and charge it daily for 90 days. They were also asked to complete a daily symptom diary. At the end of the study period, participants were asked what would motivate them to regularly use a wearable for monitoring of their COPD. Of 28 patients enrolled, 16 participants completed the full 90 days. The average age of participants was 68.5 years, and 36% (10/28) were women. Survey, heart rate, and activity data were available for an average of 64.5, 65.1, and 60.2 days respectively. Technical issues caused heart rate and activity data to be unavailable for approximately 13 and 17 days, respectively. Feedback provided by participants indicated that they wanted to actively engage with the smartwatch and receive feedback about their activity, heart rate, and how to better manage their COPD. Some patients with COPD will wear and maintain smartwatches that passively monitor audio, heart rate, and physical activity, and wearables were able to reliably capture near-continuous patient data. Further work is necessary to increase acceptability and improve the patient experience. ©Robert Wu, Daniyal Liaqat, Eyal de Lara, Tatiana Son, Frank Rudzicz, Hisham Alshaer, Pegah Abed-Esfahani, Andrea S Gershon. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 14.06.2018.

Home blood pressure variability on one occasion is a novel factor associated with arterial stiffness in patients with type 2 diabetes.

PubMed

Fukui, Michiaki; Ushigome, Emi; Tanaka, Muhei; Hamaguchi, Masahide; Tanaka, Toru; Atsuta, Haruhiko; Ohnishi, Masayoshi; Oda, Yohei; Hasegawa, Goji; Nakamura, Naoto

2013-03-01

Recent studies have suggested that not only mean blood pressure but also variability in blood pressure might be related to cardiovascular disease. The aim of this study was to investigate the association between home blood pressure variability on one occasion and markers of arterial stiffness in patients with type 2 diabetes. We investigated the relationship between the s.d. of clinic- or home-measured systolic blood pressure on one occasion and pulse wave velocity (PWV) in 332 patients with type 2 diabetes, and we evaluated whether the SD of clinic- or home-measured systolic blood pressure on one occasion was an independent determinant of PWV by multivariate linear regression analysis, after adjustment for known risk factors for arterial stiffness, including sex, age, duration of diabetes, body mass index, hemoglobin A1c, serum total cholesterol, triglycerides, smoking status, drinking alcohol, presence of antihypertensive medication, average systolic blood pressure and heart rate. Age, average morning home-measured systolic blood pressure, heart rate and PWV (r=0.259, P<0.0001) were positively correlated with the s.d. of morning home blood pressure on one occasion. Multiple regression analysis demonstrated that age, average morning home-measured systolic blood pressure (P=0.0019), heart rate and the s.d. of morning home-measured systolic blood pressure on one occasion (P=0.0159) were independently associated with PWV. In conclusion, home blood pressure variability on one occasion was correlated with PWV, independent of other known risk factors, in Japanese patients with type 2 diabetes.

Blood pressure variability in man: its relation to high blood pressure, age and baroreflex sensitivity.

PubMed

Mancia, G; Ferrari, A; Gregorini, L; Parati, G; Pomidossi, G; Bertinieri, G; Grassi, G; Zanchetti, A

1980-12-01

1. Intra-arterial blood pressure and heart rate were recorded for 24 h in ambulant hospitalized patients of variable age who had normal blood pressure or essential hypertension. Mean 24 h values, standard deviations and variation coefficient were obtained as the averages of values separately analysed for 48 consecutive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation aations and variation coefficient were obtained as the averages of values separately analysed for 48 consecurive half-hour periods. 2. In older subjects standard deviation and variation coefficient for mean arterial pressure were greater than in younger subjects with similar pressure values, whereas standard deviation and variation coefficient for heart rate were smaller. 3. In hypertensive subjects standard deviation for mean arterial pressure was greater than in normotensive subjects of similar ages, but this was not the case for variation coefficient, which was slightly smaller in the former than in the latter group. Normotensive and hypertensive subjects showed no difference in standard deviation and variation coefficient for heart rate. 4. In both normotensive and hypertensive subjects standard deviation and even more so variation coefficient were slightly or not related to arterial baroreflex sensitivity as measured by various methods (phenylephrine, neck suction etc.). 5. It is concluded that blood pressure variability increases and heart rate variability decreases with age, but that changes in variability are not so obvious in hypertension. Also, differences in variability among subjects are only marginally explained by differences in baroreflex function.

[Metformin and changes in blood pressure and heart rate in lean patients with polycystic ovary syndrome (PCOS)--preliminary study].

PubMed

Tomczyk, Rita; Ociepka, Agnieszka; Kiałka, Marta; Milewicz, Tomasz; Migacz, Kamila; Kowalczuk, Aleksandra; Klocek, Marek

2015-01-01

The aim of our study was to assess the value of blood pressure and heart rate using the 24-hour blood pressure monitoring (ABPM) before and after treatment with metformin to patients with polycystic ovary syndrome (PCOS) and normal lean. 5 patients received metformin 1500 mg per day in three divided doses. ABPM was performed to each patient with PCOS twice: before and after 6 months of treatment with metformin. In patients with PCOS and normal lean after treatment with metformin we observed: statistically significant lower systolic blood pressure (120.2 ± 22.33 mmHg vs 113.22 ± 21.43 mm Hg, p = 0.0248); lower systolic blood pressure of daily measurements (127.1 ± 32.13 mmHg vs 116.1 ± 22.08 mmHg, p = 0.0062); reduction in average arterial pressure MAP in the measurement of the day (95.52 ± 22.76 mmHg vs 88.36 ± 16.41 mmHg, p = 0.048); oscillometric pressure reduction (96.27 ± 27.93 mmHg vs 87.82 ± 21.61, p = 0.0004 mmHg); oscillometric pressure reduction of daily measurements (102.1 ± 27.93 mmHg vs 91.85 ± 21.61 mmHg, p = 0.0032); oscillometric pressure reduction in the measure- ment of the night (88.81 ± 24.85 mmHg vs 82.22 ± 20.54 mmHg, p = 0.0089). In women after treatment with metformin has also been observed higher average heart rate (65.82 ± 13.48 / min vs. 70.71 ± 16.04 min; p < 0.01). The calculations included 500 measurements. Treatment with metformin in patients with PCOS and normal lean leads to lower blood pressure and increases the frequency of heart rate.

Hybrid ECG signal conditioner

NASA Technical Reports Server (NTRS)

Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

1979-01-01

Circuit with high common-mode rejection has ability to filter and amplify accepted analog electrocardiogram (ECG) signals of varying amplitude, shape, and polarity. In addition, low power circuit develops standardized pulses that can be counted and averaged by heart/breath rate processor.

Racial differences in dietary antioxidant intake and cardiac event-free survival in patients with heart failure.

PubMed

Wu, Jia-Rong; Song, Eun Kyeung; Moser, Debra K; Lennie, Terry A

2018-04-01

Heart failure is a chronic, burdensome condition with higher re-hospitalization rates in African Americans than Whites. Higher dietary antioxidant intake is associated with lower oxidative stress and improved endothelial function. Lower dietary antioxidant intake in African Americans may play a role in the re-hospitalization disparity between African American and White patients with heart failure. The objective of this study was to examine the associations among race, dietary antioxidant intake, and cardiac event-free survival in patients with heart failure. In a secondary analysis of 247 patients with heart failure who completed a four-day food diary, intake of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, zeaxanthin, lycopene, vitamins C and E, zinc, and selenium were assessed. Antioxidant deficiency was defined as intake below the estimated average requirement for antioxidants with an established estimated average requirement, or lower than the sample median for antioxidants without an established estimated average requirement. Patients were followed for a median of one year to determine time to first cardiac event (hospitalization or death). Survival analysis was used for data analysis. African American patients had more dietary antioxidant deficiencies and a shorter cardiac event-free survival compared with Whites ( p = .007 and p = .028, respectively). In Cox regression, race and antioxidant deficiency were associated with cardiac event-free survival before and after adjusting for covariates. African Americans with heart failure had more dietary antioxidant deficiencies and shorter cardiac event-free survival than Whites. This suggests that encouraging African American patients with heart failure to consume an antioxidant-rich diet may be beneficial in lengthening cardiac event-free survival.

Exposure of the Heart in Breast Cancer Radiation Therapy: A Systematic Review of Heart Doses Published During 2003 to 2013.

PubMed

Taylor, Carolyn W; Wang, Zhe; Macaulay, Elizabeth; Jagsi, Reshma; Duane, Frances; Darby, Sarah C

2015-11-15

Breast cancer radiation therapy cures many women, but where the heart is exposed, it can cause heart disease. We report a systematic review of heart doses from breast cancer radiation therapy that were published during 2003 to 2013. Eligible studies were those reporting whole-heart dose (ie, dose averaged over the whole heart). Analyses considered the arithmetic mean of the whole-heart doses for the CT plans for each regimen in each study. We termed this "mean heart dose." In left-sided breast cancer, mean heart dose averaged over all 398 regimens reported in 149 studies from 28 countries was 5.4 Gy (range, <0.1-28.6 Gy). In regimens that did not include the internal mammary chain (IMC), average mean heart dose was 4.2 Gy and varied with the target tissues irradiated. The lowest average mean heart doses were from tangential radiation therapy with either breathing control (1.3 Gy; range, 0.4-2.5 Gy) or treatment in the lateral decubitus position (1.2 Gy; range, 0.8-1.7 Gy), or from proton radiation therapy (0.5 Gy; range, 0.1-0.8 Gy). For intensity modulated radiation therapy mean heart dose was 5.6 Gy (range, <0.1-23.0 Gy). Where the IMC was irradiated, average mean heart dose was around 8 Gy and varied little according to which other targets were irradiated. Proton radiation therapy delivered the lowest average mean heart dose (2.6 Gy, range, 1.0-6.0 Gy), and tangential radiation therapy with a separate IMC field the highest (9.2 Gy, range, 1.9-21.0 Gy). In right-sided breast cancer, the average mean heart dose was 3.3 Gy based on 45 regimens in 23 studies. Recent estimates of typical heart doses from left breast cancer radiation therapy vary widely between studies, even for apparently similar regimens. Maneuvers to reduce heart dose in left tangential radiation therapy were successful. Proton radiation therapy delivered the lowest doses. Inclusion of the IMC doubled typical heart dose. Copyright © 2015 Elsevier Inc. All rights reserved.

The predictive value of the heart-rate-variability derived Analgesia Nociception Index in children anaesthetised with sevoflurane - an observational pilot-study.

PubMed

Weber, Frank; Geerts, Noortje J E; Roeleveld, Hilde G; Warmenhoven, Annejet T; Liebrand, Chantal A

2018-05-13

The heart rate variability (HRV) derived Analgesia Nociception Index (ANI ™ ) is a continuous non-invasive tool to assess the nociception/anti-nociception balance in unconscious patients. It has been shown to be superior to hemodynamic variables in detecting insufficient anti-nociception in children, while little is known about its predictive value. The primary objective of this prospective observational pilot study in paediatric surgical patients under sevoflurane anaesthesia, was to compare the predictive value of the ANI and heart rate to help decide to give additional opioids. The paediatric anaesthesiologist in charge was blinded to ANI values. In patients with an ANI value <50 (indicating insufficient anti-nociception) at the moment of decision, ANI values dropped from ±55 (indicating sufficient anti-nociception) to ±35, starting 60 sec. before decision. Within 120 sec. after administration of fentanyl (1 mcg/kg), ANI values returned to ±60. This phenomenon was only observed in the ANI values derived from HRV data averaged over 2 min. Heart rate remained unchanged. In patients with ANI values ≥50 at the time of decision, opioid administration had no effect on ANI or heart rate. The same accounts for morphine for postoperative analgesia and fentanyl in case of intraoperative movement. This study provides evidence of a better predictive value of the ANI in detecting insufficient anti-nociception in paediatric surgical patients than heart rate. The same accounts for depicting re-establishment of sufficient anti-nociception after opioid drug administration. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Risk of ischemic heart disease in women after radiotherapy for breast cancer.

PubMed

Darby, Sarah C; Ewertz, Marianne; McGale, Paul; Bennet, Anna M; Blom-Goldman, Ulla; Brønnum, Dorthe; Correa, Candace; Cutter, David; Gagliardi, Giovanna; Gigante, Bruna; Jensen, Maj-Britt; Nisbet, Andrew; Peto, Richard; Rahimi, Kazem; Taylor, Carolyn; Hall, Per

2013-03-14

Radiotherapy for breast cancer often involves some incidental exposure of the heart to ionizing radiation. The effect of this exposure on the subsequent risk of ischemic heart disease is uncertain. We conducted a population-based case-control study of major coronary events (i.e., myocardial infarction, coronary revascularization, or death from ischemic heart disease) in 2168 women who underwent radiotherapy for breast cancer between 1958 and 2001 in Sweden and Denmark; the study included 963 women with major coronary events and 1205 controls. Individual patient information was obtained from hospital records. For each woman, the mean radiation doses to the whole heart and to the left anterior descending coronary artery were estimated from her radiotherapy chart. The overall average of the mean doses to the whole heart was 4.9 Gy (range, 0.03 to 27.72). Rates of major coronary events increased linearly with the mean dose to the heart by 7.4% per gray (95% confidence interval, 2.9 to 14.5; P<0.001), with no apparent threshold. The increase started within the first 5 years after radiotherapy and continued into the third decade after radiotherapy. The proportional increase in the rate of major coronary events per gray was similar in women with and women without cardiac risk factors at the time of radiotherapy. Exposure of the heart to ionizing radiation during radiotherapy for breast cancer increases the subsequent rate of ischemic heart disease. The increase is proportional to the mean dose to the heart, begins within a few years after exposure, and continues for at least 20 years. Women with preexisting cardiac risk factors have greater absolute increases in risk from radiotherapy than other women. (Funded by Cancer Research UK and others.).

Contact-free heart rate measurement using multiple video data

NASA Astrophysics Data System (ADS)

Hung, Pang-Chan; Lee, Kual-Zheng; Tsai, Luo-Wei

2013-10-01

In this paper, we propose a contact-free heart rate measurement method by analyzing sequential images of multiple video data. In the proposed method, skin-like pixels are firstly detected from multiple video data for extracting the color features. These color features are synchronized and analyzed by independent component analysis. A representative component is finally selected among these independent component candidates to measure the HR, which achieves under 2% deviation on average compared with a pulse oximeter in the controllable environment. The advantages of the proposed method include: 1) it uses low cost and high accessibility camera device; 2) it eases users' discomfort by utilizing contact-free measurement; and 3) it achieves the low error rate and the high stability by integrating multiple video data.

Effects of subchronic exposures to concentrated ambient particles (CAPs) in mice. III. Acute and chronic effects of CAPs on heart rate, heart-rate fluctuation, and body temperature.

PubMed

Hwang, Jing-Shiang; Nadziejko, Christine; Chen, Lung Chi

2005-04-01

Normal mice (C57) and mice prone to develop atherosclerosis (ApoE-/-) were implanted with electrocardiograph (EKG), core body temperature, and motion transmitters were exposed daily for 6 h to Tuxedo, NY, concentrated ambient particles (CAPs) for 5 day/wk during the spring and summer of 2003. The series of 5-min EKG monitoring and body-temperature measurements were obtained for each animal in the CAPs and filtered air sham exposure groups. Our hypothesis was that chronic exposure could cause cumulative health effects. We used our recently developed nonparametric method to estimate the daily time periods that mean heart rates (HR), body temperature, and physical activity differed significantly between the CAPs and sham exposed group. CAPs exposure most affected heart rate between 1:30 a.m. and 4:30 a.m. With the response variables being the average heart rate, body temperature, and physical activity, we adopted a two-stage modeling approach to obtain the estimates of chronic and acute effects on the changes of these three response variables. In the first stage, a time-varying model estimated daily crude effects. In the second stage, the true means of the estimated crude effects were modeled with a polynominal function of time for chronic effects, a linear term of daily CAPs exposure concentrations for acute effects, and a random component for unknown noise. A Bayesian framework combined these two stages. There were significant decreasing patterns of HR, body temperature, and physical activity for the ApoE-/- mice over the 5 mo of CAPs exposure, with smaller and nonsignificant changes for the C57 mice. The chronic effect changes of the three response variables for ApoE-/- mice were maximal in the last few weeks. There was also a significant relationship between CAPs exposure concentration and short-term changes of heart rate in ApoE-/- mice during exposure. Response variables were also defined for examining fluctuations of 5-min heart rates within long (i.e., 3-6 h) and short time periods (i.e., approximately 15 min). The results for the ApoE-/- mice showed that heart-rate fluctuation within the longer periods increased to 1.35-fold by the end of exposure experiment, while the heart-rate fluctuation within 15 min decreased to 0.7-fold.

Electrical alternans during rest and exercise as predictors of vulnerability to ventricular arrhythmias

NASA Technical Reports Server (NTRS)

Estes, N. A. 3rd; Michaud, G.; Zipes, D. P.; El-Sherif, N.; Venditti, F. J.; Rosenbaum, D. S.; Albrecht, P.; Wang, P. J.; Cohen, R. J.

1997-01-01

This investigation was performed to evaluate the feasibility of detecting repolarization alternans with the heart rate elevated with a bicycle exercise protocol. Sensitive spectral signal-processing techniques are able to detect beat-to-beat alternation of the amplitude of the T wave, which is not visible on standard electrocardiogram. Previous animal and human investigations using atrial or ventricular pacing have demonstrated that T-wave alternans is a marker of vulnerability to ventricular arrhythmias. Using a spectral analysis technique incorporating noise reduction signal-processing software, we evaluated electrical alternans at rest and with the heart rate elevated during a bicycle exercise protocol. In this study we defined optimal criteria for electrical alternans to separate patients from those without inducible arrhythmias. Alternans and signal-averaged electrocardiographic results were compared with the results of vulnerability to ventricular arrhythmias as defined by induction of sustained ventricular tachycardia or fibrillation at electrophysiologic evaluation. In 27 patients alternans recorded at rest and with exercise had a sensitivity of 89%, specificity of 75%, and overall clinical accuracy of 80% (p <0.003). In this patient population the signal-averaged electrocardiogram was not a significant predictor of arrhythmia vulnerability. This is the first study to report that repolarization alternans can be detected with heart rate elevated with a bicycle exercise protocol. Alternans measured using this technique is an accurate predictor of arrhythmia inducibility.

Physiological and subjective measures of workload when shovelling with a conventional and two-handled ('levered') shovel.

PubMed

Bridger, R S; Cabion, N; Goedecke, J; Rickard, S; Schabort, E; Westgarth-Taylor, C; Lambert, M I

1997-11-01

Previous studies have suggested that the two-handled (levered) shovel is advantageous over the conventional spade from a biomechanical point of view. The aim of this experiment was to determine whether less energy was consumed while shovelling a load of sand with this shovel compared to a conventional tool. Accordingly, an experiment was designed in which subjects (n = 10) shovelled 1815 kg sand under laboratory conditions using either a conventional or a levered shovel. Heart rate and oxygen consumption were measured continuously during the trial and subjective data on perceived exertion, general fatigue and body discomfort were recorded after the trial. Although total energy expenditure was similar under both conditions (120 +/- 20 and 125 +/- 25 kcal; conventional versus two-handled spade), average heart rate was 4% higher when the two-handled shovel was used (p < 0.05). In addition, the mass of sand per scoop was 4% less with the two-handled shovel (p < 0.05). In conclusion, subjects used similar energy expenditure to shovel 1815 kg sand with the conventional shovel and the two-handled tool despite lower mass of sand per scoop with the latter. This can be explained by the fact that the increased mass of the additional handle compensated for the lower mass of sand per scoop. The higher average heart rate while shovelling with the two-handled shovel can be explained by the more erect posture.

Predicting Bradycardia in Preterm Infants Using Point Process Analysis of Heart Rate.

PubMed

Gee, Alan H; Barbieri, Riccardo; Paydarfar, David; Indic, Premananda

2017-09-01

Episodes of bradycardia are common and recur sporadically in preterm infants, posing a threat to the developing brain and other vital organs. We hypothesize that bradycardias are a result of transient temporal destabilization of the cardiac autonomic control system and that fluctuations in the heart rate signal might contain information that precedes bradycardia. We investigate infant heart rate fluctuations with a novel application of point process theory. In ten preterm infants, we estimate instantaneous linear measures of the heart rate signal, use these measures to extract statistical features of bradycardia, and propose a simplistic framework for prediction of bradycardia. We present the performance of a prediction algorithm using instantaneous linear measures (mean area under the curve = 0.79 ± 0.018) for over 440 bradycardia events. The algorithm achieves an average forecast time of 116 s prior to bradycardia onset (FPR = 0.15). Our analysis reveals that increased variance in the heart rate signal is a precursor of severe bradycardia. This increase in variance is associated with an increase in power from low content dynamics in the LF band (0.04-0.2 Hz) and lower multiscale entropy values prior to bradycardia. Point process analysis of the heartbeat time series reveals instantaneous measures that can be used to predict infant bradycardia prior to onset. Our findings are relevant to risk stratification, predictive monitoring, and implementation of preventative strategies for reducing morbidity and mortality associated with bradycardia in neonatal intensive care units.

The Effect of Music Therapy Entrainment on Physiologic Measures of Infants in the Cardiac Intensive Care Unit: Single Case Withdrawal Pilot Study.

PubMed

Yurkovich, Jennifer; Burns, Debra S; Harrison, Tondi

2018-03-09

Although evidence suggests music therapy lowers the heart rate of ill adults undergoing painful procedures and premature infants in the NICU, the effect of music therapy interventions on physiologic response in infants with congenital heart disease (CHD) being cared for in the cardiac intensive care unit (CICU) has not been explored. The purpose of this study was to explore the effect of the music therapy entrainment on physiologic responses of infants with CHD in the CICU. Five infants in the CICU received music therapy entrainment 3-5 times per week for up to 3 weeks. Sessions took place both prior to and after the infant's surgical cardiac repair. Heart rate, respiratory rate, blood pressure, and oxygen saturations were recorded every 15 seconds for 20 minutes prior to the intervention (baseline), during the 20-minute music therapy entrainment (intervention), and for 20 minutes after the intervention (return to baseline). Comparisons of baseline to intervention measures were based on means, standard deviations, and derivatives of the signal. Four of 5 infants experienced a decrease in average heart and respiratory rates as well as improvement in the derivative of the heart rate signal. Greater improvements were found when infants were located in the open bay and were receiving sedatives or narcotics. Our findings provide initial evidence that music therapy entrainment may be a valuable intervention to support improved physiologic stability in infants with CHD.

Improved detection of congestive heart failure via probabilistic symbolic pattern recognition and heart rate variability metrics.

PubMed

Mahajan, Ruhi; Viangteeravat, Teeradache; Akbilgic, Oguz

2017-12-01

A timely diagnosis of congestive heart failure (CHF) is crucial to evade a life-threatening event. This paper presents a novel probabilistic symbol pattern recognition (PSPR) approach to detect CHF in subjects from their cardiac interbeat (R-R) intervals. PSPR discretizes each continuous R-R interval time series by mapping them onto an eight-symbol alphabet and then models the pattern transition behavior in the symbolic representation of the series. The PSPR-based analysis of the discretized series from 107 subjects (69 normal and 38 CHF subjects) yielded discernible features to distinguish normal subjects and subjects with CHF. In addition to PSPR features, we also extracted features using the time-domain heart rate variability measures such as average and standard deviation of R-R intervals. An ensemble of bagged decision trees was used to classify two groups resulting in a five-fold cross-validation accuracy, specificity, and sensitivity of 98.1%, 100%, and 94.7%, respectively. However, a 20% holdout validation yielded an accuracy, specificity, and sensitivity of 99.5%, 100%, and 98.57%, respectively. Results from this study suggest that features obtained with the combination of PSPR and long-term heart rate variability measures can be used in developing automated CHF diagnosis tools. Copyright © 2017 Elsevier B.V. All rights reserved.

[CARDIOREABILITATION PECULIARITIES AND CORRECTION OF VIOLATIONS OF SISTOLIC, DIASOLIC FUNCTION AND HEART RATE VARIABILITY IN PATIENTS WITH ACUTE CORONARY SYNDROME AND CORONARY ARTERY REVASCULARIZATION].

PubMed

Shved, M; Tsuglevych, L; Kyrychok, I; Levytska, L; Boiko, T; Kitsak, Ya

2017-04-01

In patients with acute coronary syndrome (ACS) who underwent coronary arteries revascularization, violations of hemodynamics, metabolism and heart rate variability often develop in the postoperative period, therefore, the goal of the study was to establish the features of disturbances and the effectiveness of correction of left ventricular systolic and diastolic dysfunction and heart rate variability in stages of cardiorehabilitation in patients with acute coronary syndrome who underwent coronary arteries revascularization. The experimental group included 40 patients with ACS in the postoperative period who underwent balloon angioplasty and stenting of the coronary arteries (25 patients with ST-segment elevation ACS and 15 patients without ST-segment elevation ACS). The age of examined patients was 37 to 74 years, an average of 52.6±6.7 years. The control group consisted of 20 patients, comparable in age and clinico-laboratory manifestations of ACS, who underwent drug treatment with direct anticoagulants, double antiplatelet therapy, β-blockers, ACE inhibitors and statins. Clinical efficacy of cardiorespiratory process in patients of both groups was assessed by the dynamics of general clinical symptoms and parameters of natriuretic propeptide, systolic and diastolic function of the left ventricle and heart rate variability. In the initial state, clinical and laboratory-instrumental signs of myocardial ischemia disappear in patients with ACS undergoing surgical revascularization of the coronary arteries, but clinical and subclinical manifestations of heart failure were diagnosed. The use of the accelerated program of cardiac rehabilitation already during the first month of studies leads to a decreasement of the signs of systolic and diastolic dysfunction, the level of NT-proBNP and improve in the variability of the heart rhythm wich significantly improves the life quality of patients with ACS. To monitor the effectiveness and safety of cardiac rehabilitation in patients with ACS who underwent coronary arteries revascularization, in addition to the generally accepted methods (determination of heart rate, blood pressure, a 6-minute test), it is advisable to diagnose the subclinical stage of heart failure by determining the level of NT-proBNP, Doppler echocardiogram, parameters of the left ventricular systolic and diastolic function and heart rate variability.

Tolazoline decreases survival time during microwave-induced lethal heat stress in anesthetized rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jauchem, J.R.; Chang, K.S.; Frei, M.R.

1996-03-01

Effects of {alpha}-adrenergic antagonists have been studied during environmental heating but not during microwave-induced heating. Tolazoline may exert some of its effects via {alpha}-adrenergic blockade. In the present study, ketamine-anesthetized Sprague-Dawley rats were exposed to 2450-MHz microwaves at an average power density of 60 mW/cm{sup 2} (whole-body specific absorption rate of approximately 14 W/kg) until lethal temperatures were attained. The effects of tolazoline (10 mg/kg body weight) on physiological responses (including changes in body temperature, heart rate, blood pressure, and respiratory rate) were examined. Survival time was significantly shorter in the tolazoline group than in saline-treated animals. In general, heartmore » rate and blood pressure responses were similar to those that occur during environmental heat stress. Heart rate, however, was significantly elevated in animals that received tolazoline, both before and during terminal microwave exposure. It is possible that changes associated with the elevated heart rate (e.g., less cardiac filling) in tolazoline-treated animals resulted in greater susceptibility to microwave-induced heating and the lower survival time. 47 refs., 3 figs., 2 tabs.« less

Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure After Marital Separation.

PubMed

Bourassa, Kyle J; Allen, John J B; Mehl, Matthias R; Sbarra, David A

Divorce is a common stressor that is associated with increased risk for poor long-term physical and mental health. Using an experimental design, the current study examined the impact of expressive writing (EW) on average heart rate (HR), HR variability (HRV), and blood pressure (BP) 7.5 months later. Participants from a community sample of recently separated adults (N = 109) were assigned to one of three conditions: traditional EW, narrative EW, or a control writing condition, and were assessed three times for an average of 7.5 months. Each study visit included 27 minutes of physiological assessment; the primary outcomes at each assessment were mean-level HR, HRV, BP scores averaged across six different tasks. Participants in the traditional EW condition did not significantly differ from control participants in their later HR, HRV, or BP. However, relative to control participants, those in the narrative EW condition had significantly lower HR (B = -3.41, 95% confidence interval = -5.76 to -1.06, p = .004) and higher HRV 7.5 months later (B = 0.41, 95% confidence interval = 0.16 to 0.74, p = .001). When comparing narrative EW participants to those in the traditional EW and control writing as a single group, these effects remained and were moderately sized, Cohen d values of -0.61 and 0.60, respectively, and durable across all task conditions when analyzed in independent models. The writing condition groups did not differ in their later BP. Narrative EW decreased HR and increased HRV after marital separation but did not affect BP. We discuss the possible disconnect between psychology and physiology in response to EW, as well as possible future clinical applications after marital separation.

The reliability and accuracy of estimating heart-rates from RGB video recorded on a consumer grade camera

NASA Astrophysics Data System (ADS)

Eaton, Adam; Vincely, Vinoin; Lloyd, Paige; Hugenberg, Kurt; Vishwanath, Karthik

2017-03-01

Video Photoplethysmography (VPPG) is a numerical technique to process standard RGB video data of exposed human skin and extracting the heart-rate (HR) from the skin areas. Being a non-contact technique, VPPG has the potential to provide estimates of subject's heart-rate, respiratory rate, and even the heart rate variability of human subjects with potential applications ranging from infant monitors, remote healthcare and psychological experiments, particularly given the non-contact and sensor-free nature of the technique. Though several previous studies have reported successful correlations in HR obtained using VPPG algorithms to HR measured using the gold-standard electrocardiograph, others have reported that these correlations are dependent on controlling for duration of the video-data analyzed, subject motion, and ambient lighting. Here, we investigate the ability of two commonly used VPPG-algorithms in extraction of human heart-rates under three different laboratory conditions. We compare the VPPG HR values extracted across these three sets of experiments to the gold-standard values acquired by using an electrocardiogram or a commercially available pulseoximeter. The two VPPG-algorithms were applied with and without KLT-facial feature tracking and detection algorithms from the Computer Vision MATLAB® toolbox. Results indicate that VPPG based numerical approaches have the ability to provide robust estimates of subject HR values and are relatively insensitive to the devices used to record the video data. However, they are highly sensitive to conditions of video acquisition including subject motion, the location, size and averaging techniques applied to regions-of-interest as well as to the number of video frames used for data processing.

Cold-induced bradycardia in man during sleep in Arctic winter nights

NASA Astrophysics Data System (ADS)

Buguet, A. G. C.

1987-03-01

Two young male Caucasians volunteered for a study on the effects of cold exposure during night sleep in winter in the Arctic. The 14-day experiment was divided in three consecutive periods, baseline (2 nights), cold exposure (10 night) and recovery (2 nights). Both baseline and recovery data were obtained in neutral thermal conditions in a laboratory. The subjects slept in a sleeping bag under an unheated tent during the cold exposure. Apart from polysomnographic and body temperature recordings, electrocardiograms were taken through a telemetric system for safety purposes. Heart rates were noted at 5-min intervals and averaged hourly. In both environmental conditions, heart rate decreased within the first two hours of sleep. Comparison of the data obtained during cold exposure vs. thermal neutrality revealed lower values of heart rate in the cold, while body temperatures remained within normal range. This cold-induced bradycardia supervening during night sleep is discussed in terms of the occurrence of a vagal reflex preventing central blood pressure to rise.

Do thallium myocardial perfusion scan abnormalities predict survival in sarcoid patients without cardiac symptoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinney, E.L.; Caldwell, J.W.

1990-07-01

Whereas the total mortality rate for sarcoidosis is 0.2 per 100,000, the prognosis, when the heart is involved, is very much worse. The authors used the difference in mortality rate to infer whether thallium 201 myocardial perfusion scan abnormalities correspond to myocardial sarcoid by making the simplifying assumption that if they do, then patients with abnormal scans will be found to have a death rate similar to patients with sarcoid heart disease. The authors therefore analyzed complete survival data on 52 sarcoid patients without cardiac symptoms an average of eighty-nine months after they had been scanned as part of amore » protocol. By use of survival analysis (the Cox proportional hazards model), the only variable that was significantly associated with survival was age. The patients' scan pattern, treatment status, gender, and race were not significantly related to survival. The authors conclude that thallium myocardial perfusion scans cannot reliably be used to diagnose sarcoid heart disease in sarcoid patients without cardiac symptoms.« less

Use and physiological responses of portable dynamic office workstations in an occupational setting - A field study.

PubMed

Schellewald, Vera; Kleinert, Jens; Ellegast, Rolf

2018-09-01

The aim of this study was to investigate the use of two types of dynamic workstations (Deskbike, activeLife Trainer) and their effects on physiological activation in an occupational setting. 30 employees were given access to the devices for 28 days. Frequency and duration of borrowing and use was recorded by a Chipcard-system. Physiological activation (energy expenditure, heart rate) while working in a seated position and using the workstations was measured with the activity tracker Fitbit Charge HR. Participants used dynamic workstations on 40% of their working days for an average of 54.3 ± 23.9 min per day. Energy expenditure and heart rate increased significantly while using the workstations compared to working seated. The Deskbike was used more frequently and resulted in greater heart rate elevation. Both types of dynamic workstations were used by the employees and had positive effects on physiological activation. The implementation of either type can be recommended. Copyright © 2018 Elsevier Ltd. All rights reserved.

Exposure of the Heart in Breast Cancer Radiation Therapy: A Systematic Review of Heart Doses Published During 2003 to 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Carolyn W., E-mail: carolyn.taylor@ctsu.ox.ac.uk; Wang, Zhe; Macaulay, Elizabeth

Purpose: Breast cancer radiation therapy cures many women, but where the heart is exposed, it can cause heart disease. We report a systematic review of heart doses from breast cancer radiation therapy that were published during 2003 to 2013. Methods and Materials: Eligible studies were those reporting whole-heart dose (ie, dose averaged over the whole heart). Analyses considered the arithmetic mean of the whole-heart doses for the CT plans for each regimen in each study. We termed this “mean heart dose.” Results: In left-sided breast cancer, mean heart dose averaged over all 398 regimens reported in 149 studies from 28more » countries was 5.4 Gy (range, <0.1-28.6 Gy). In regimens that did not include the internal mammary chain (IMC), average mean heart dose was 4.2 Gy and varied with the target tissues irradiated. The lowest average mean heart doses were from tangential radiation therapy with either breathing control (1.3 Gy; range, 0.4-2.5 Gy) or treatment in the lateral decubitus position (1.2 Gy; range, 0.8-1.7 Gy), or from proton radiation therapy (0.5 Gy; range, 0.1-0.8 Gy). For intensity modulated radiation therapy mean heart dose was 5.6 Gy (range, <0.1-23.0 Gy). Where the IMC was irradiated, average mean heart dose was around 8 Gy and varied little according to which other targets were irradiated. Proton radiation therapy delivered the lowest average mean heart dose (2.6 Gy, range, 1.0-6.0 Gy), and tangential radiation therapy with a separate IMC field the highest (9.2 Gy, range, 1.9-21.0 Gy). In right-sided breast cancer, the average mean heart dose was 3.3 Gy based on 45 regimens in 23 studies. Conclusions: Recent estimates of typical heart doses from left breast cancer radiation therapy vary widely between studies, even for apparently similar regimens. Maneuvers to reduce heart dose in left tangential radiation therapy were successful. Proton radiation therapy delivered the lowest doses. Inclusion of the IMC doubled typical heart dose.« less

Serial optical coherence scanning reveals an association between cardiac function and the heart architecture in the aging rodent heart

PubMed Central

Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Avti, Pramod; Moeini, Mohammad; Lesage, Frédéric

2017-01-01

Normal aging is accompanied by structural changes in the heart architecture. To explore this remodeling, we used a serial optical coherence tomography scanner to image entire mouse hearts at micron scale resolution. Ex vivo hearts of 7 young (4 months) and 5 old (24 months) C57BL/6 mice were acquired with the imaging platform. OCT of the myocardium revealed myofiber orientation changing linearly from the endocardium to the epicardium. In old mice, this rate of change was lower when compared to young mice while the average volume of old mice hearts was significantly larger (p<0.05). Myocardial wall thickening was also accompanied by extracellular spacing in the endocardium, resulting in a lower OCT attenuation coefficient in old mice endocardium (p<0.05). Prior to serial sectioning, cardiac function of the same hearts was imaged in vivo using MRI and revealed a reduced ejection fraction with aging. The use of a serial optical coherence tomography scanner allows new insight into fine age-related changes of the heart associated with changes in heart function. PMID:29188099

Development of an anaerobic threshold (HRLT, HRVT) estimation equation using the heart rate threshold (HRT) during the treadmill incremental exercise test

PubMed Central

Ham, Joo-ho; Park, Hun-Young; Kim, Youn-ho; Bae, Sang-kon; Ko, Byung-hoon

2017-01-01

[Purpose] The purpose of this study was to develop a regression model to estimate the heart rate at the lactate threshold (HRLT) and the heart rate at the ventilatory threshold (HRVT) using the heart rate threshold (HRT), and to test the validity of the regression model. [Methods] We performed a graded exercise test with a treadmill in 220 normal individuals (men: 112, women: 108) aged 20–59 years. HRT, HRLT, and HRVT were measured in all subjects. A regression model was developed to estimate HRLT and HRVT using HRT with 70% of the data (men: 79, women: 76) through randomization (7:3), with the Bernoulli trial. The validity of the regression model developed with the remaining 30% of the data (men: 33, women: 32) was also examined. [Results] Based on the regression coefficient, we found that the independent variable HRT was a significant variable in all regression models. The adjusted R2 of the developed regression models averaged about 70%, and the standard error of estimation of the validity test results was 11 bpm, which is similar to that of the developed model. [Conclusion] These results suggest that HRT is a useful parameter for predicting HRLT and HRVT. PMID:29036765

Development of an anaerobic threshold (HRLT, HRVT) estimation equation using the heart rate threshold (HRT) during the treadmill incremental exercise test.

PubMed

Ham, Joo-Ho; Park, Hun-Young; Kim, Youn-Ho; Bae, Sang-Kon; Ko, Byung-Hoon; Nam, Sang-Seok

2017-09-30

The purpose of this study was to develop a regression model to estimate the heart rate at the lactate threshold (HRLT) and the heart rate at the ventilatory threshold (HRVT) using the heart rate threshold (HRT), and to test the validity of the regression model. We performed a graded exercise test with a treadmill in 220 normal individuals (men: 112, women: 108) aged 20-59 years. HRT, HRLT, and HRVT were measured in all subjects. A regression model was developed to estimate HRLT and HRVT using HRT with 70% of the data (men: 79, women: 76) through randomization (7:3), with the Bernoulli trial. The validity of the regression model developed with the remaining 30% of the data (men: 33, women: 32) was also examined. Based on the regression coefficient, we found that the independent variable HRT was a significant variable in all regression models. The adjusted R2 of the developed regression models averaged about 70%, and the standard error of estimation of the validity test results was 11 bpm, which is similar to that of the developed model. These results suggest that HRT is a useful parameter for predicting HRLT and HRVT. ©2017 The Korean Society for Exercise Nutrition

Thermoregulatory responses of rats exposed to 9. 3-GHz radio-frequency radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frei, M.R.; Jauchem, J.R.; Heinmets, F.

1987-10-15

Ketamine-anesthetized Sprague-Dawley rats were exposed in H orientation to far-field 9.3-GHz continuous-wave (CW) and pulsed (2 microseconds 500 pps) radiofrequency radiation (RFR) at average power densities of 30 and 60 mW/sq. cm (whole-body average specific absorption rates of 9.3 and 18.6 W/kg, respectively). Irradiation was conducted to cyclicly increase colonic temperature from 38.5 to 39.5 C. Colonic, tympanic, and subcutaneous temperatures, ECG, blood pressure, and respiratory rate were continuously recorded during experimentation. At both power densities, the subcutaneous and tympanic temperature increases significantly exceeded the colonic temperature increase. At both exposure levels, heart rate increased significantly during irradiation and returnedmore » to baseline when exposure was discontinued. Blood pressure and respiratory rate did not significantly change during irradiation. There were no significant differences between the effects of CW and pulsed RFR exposure. The levels of subcutaneous heating and heart rate change were greater, and the times required to achieve and to recover from a 1 C colonic temperature increase were longer than in previous studies conducted at 2.8 GHz. Results of these studies indicate that the carrier frequency used during irradiation markedly affects the pattern of heat distribution and the physiological responses of RF-irradiated animals.« less

Evaluation of heart rhythm variability and arrhythmia in children with systemic and localized scleroderma.

PubMed

Wozniak, Jacek; Dabrowski, Rafal; Luczak, Dariusz; Kwiatkowska, Malgorzata; Musiej-Nowakowska, Elzbieta; Kowalik, Ilona; Szwed, Hanna

2009-01-01

To evaluate possible disturbances in autonomic regulation and cardiac arrhythmias in children with localized and systemic scleroderma. There were 40 children included in the study: 20 with systemic and 20 with localized scleroderma. The control group comprised 20 healthy children. In 24-hour Holter recording, the average rate of sinus rhythm was significantly higher in the groups with systemic and localized scleroderma than in the control group, but there was no significant difference between them. The variability of heart rhythm in both groups was significantly decreased. In the group with systemic scleroderma, single supraventricular ectopic beats were observed in 20% and runs were seen in 40% of patients. In the group with localized scleroderma, supraventricular single ectopic beats occurred in 35% of patients and runs in 45% of those studied. Ventricular arrhythmia occurred in 2 children with systemic scleroderma, but in 1 child, it was complex. The most frequent cardiac arrhythmias in both types of scleroderma in children were of supraventricular origin, whereas ventricular arrhythmias did not occur very often. There were no significant differences in autonomic disturbances manifesting as a higher heart rate and decreased heart rate variability between localized and systemic scleroderma.

Body heating induced by sub-resonant (350 MHz) microwave irradiation: cardiovascular and respiratory responses in anesthetized rats.

PubMed

Jauchem, J R; Frei, M R

1997-01-01

These experiments were designed to investigate the effects of sub-resonant microwave (MW) exposure (350 MHz, E orientation, average power density 38 mW/cm2, average whole-body specific absorption rate 13.2 W/kg) on selected physiological parameters. The increase in peripheral body temperature during 350 MHz exposure was greater than that in earlier experiments performed at 700 MHz (resonance). Heart rate and mean arterial blood pressure were significantly elevated during a 1 degree C increase in colonic temperature due to 350 MHz exposure; respiratory rate showed no significant change. The results are consistent with other investigators' reports comparing sub-resonance exposures with those at resonance and above.

Design of wearable health monitoring device

NASA Astrophysics Data System (ADS)

Devara, Kresna; Ramadhanty, Savira; Abuzairi, Tomy

2018-02-01

Wearable smart health monitoring devices have attracted considerable attention in both research community and industry. Some of the causes are the increasing healthcare costs, along with the growing technology. To address this demand, in this paper, design and evaluation of wearable health monitoring device integrated with smartphone were presented. This device was designed for patients in need of constant health monitoring. The performance of the proposed design has been tested by conducting measurement once in 2 minutes for 10 minutes to obtain heart rate and body temperature data. The comparation between data measured by the proposed device and that measured by the reference device yields only an average error of 1.45% for heart rate and 1.04% for body temperature.

Improved Accuracy of Automated Estimation of Cardiac Output Using Circulation Time in Patients with Heart Failure.

PubMed

Dajani, Hilmi R; Hosokawa, Kazuya; Ando, Shin-Ichi

2016-11-01

Lung-to-finger circulation time of oxygenated blood during nocturnal periodic breathing in heart failure patients measured using polysomnography correlates negatively with cardiac function but possesses limited accuracy for cardiac output (CO) estimation. CO was recalculated from lung-to-finger circulation time using a multivariable linear model with information on age and average overnight heart rate in 25 patients who underwent evaluation of heart failure. The multivariable model decreased the percentage error to 22.3% relative to invasive CO measured during cardiac catheterization. This improved automated noninvasive CO estimation using multiple variables meets a recently proposed performance criterion for clinical acceptability of noninvasive CO estimation, and compares very favorably with other available methods. Copyright © 2016 Elsevier Inc. All rights reserved.

Crackle pitch and rate do not vary significantly during a single automated-auscultation session in patients with pneumonia, congestive heart failure, or interstitial pulmonary fibrosis.

PubMed

Vyshedskiy, Andrey; Ishikawa, Sadamu; Murphy, Raymond L H

2011-06-01

To determine the variability of crackle pitch and crackle rate during a single automated-auscultation session with a computerized 16-channel lung-sound analyzer. Forty-nine patients with pneumonia, 52 with congestive heart failure (CHF), and 18 with interstitial pulmonary fibrosis (IPF) performed breathing maneuvers in the following sequence: normal breathing, deep breathing, cough several times; deep breathing, vital-capacity maneuver, and deep breathing. From the auscultation recordings we measured the crackle pitch and crackle rate. Crackle pitch variability, expressed as a percentage of the average crackle pitch, was small in all patients and in all maneuvers: pneumonia 11%, CHF 11%, pulmonary fibrosis 7%. Crackle rate variability was also small: pneumonia 31%, CHF 32%, IPF 24%. Compared to the first deep-breathing maneuver (100%), the average crackle pitch did not significantly change following coughing (pneumonia 100%, CHF 103%, IPF 100%), the vital-capacity maneuver (pneumonia 100%, CHF 92%, IPF 104%), or during quiet breathing (pneumonia 97%, CHF 100%, IPF 104%). Similarly, the average crackle rate did not change significantly following coughing (pneumonia 105%, CHF 110%, IPF 90%) or the vital-capacity maneuver (pneumonia 102%, CHF 101%, IPF 99%). However, during normal breathing the crackle rate was significantly lower in the patients with pneumonia (74%, P < .001) and significantly higher in the patients with IPF (147%, P < .05) than it was during deep breathing. In patients with CHF the average crackle rate during normal breathing was not significantly different from that during the first deep-breathing maneuver (108%). Crackle pitch and rate were surprisingly stable in all 3 conditions. Neither crackle pitch nor crackle rate changed significantly from breath to breath or from one deep-breathing maneuver to another, even when the maneuvers were separated by cough or the vital-capacity maneuver. The observation that crackle rate is a reproducible measurement during one automated-auscultation session suggests that crackle rate can be used to follow the course of cardiopulmonary illnesses such as pneumonia, IPF, and CHF.

Examining and comparing the health and performance indices of university undergraduate students according to year of study and gender

PubMed Central

Moses, Monday Omoniyi; Osei, Francis; Appiah, Eric Juniour; Obour, Agnes; Akwa, Lady Gwendoline; Baffour-Awuah, Biggie; Asamoah, Benjamin; Sarpong, Peter Akwasi; Adams, Caleb; D’Onofrio, Rosario

2017-01-01

This study examined and compared, based on year of study and gender, the health and performance indices of university undergraduate students. Eighty-nine students (mean±standard deviation age, 22.47±2.22 years) were randomly selected for assessment prior to second semester examination of 2015/2016 academic year. body mass index, resting metabolic rate, visceral fat, skeletal muscle mass, body fat, systolic & diastolic blood pressure, resting heart rate, upper & lower body endurance, handgrip strength, and lower back and hamstring flexibility were assessed. The students had sedentary heart rate, low skeletal muscle mass, average upper and lower body endurance, and weak handgrip strength. Significant difference existed in the visceral fat (P=0.008) between third and fourth year students. There were significant gender differences in resting metabolic rate (P=0.000), skeletal muscle mass (P=0.000), body fat (P=0.000), systolic blood pressure (P=0.001), heart rate (P=0.005) and handgrip strength (P=0.000). There are gender differences in association between health and performance indices. Dependable health education and pragmatic involvement of undergraduate university students in structured exercise programmes are recommended. PMID:29114505

Left ventricular function quantified by myocardial strain imaging in small-breed dogs with chronic mitral regurgitation.

PubMed

Smith, Danielle N; Bonagura, John D; Culwell, Nicole M; Schober, Karsten E

2012-03-01

The presence of left ventricular (LV) systolic dysfunction may influence prognosis or therapy in dogs with chronic mitral regurgitation (MR). Assessment of LV function in MR by conventional echocardiography is confounded by altered ventricular loading. Myocardial deformation (strain) imaging might offer more sensitive estimates of LV function in this disease. Prospectively measure myocardial strain in dogs with asymptomatic MR compared to a control group. Forty healthy dogs (3.5-11.5 kg): 20 Controls; 20 dogs with MR and LV remodeling (Stage B2), were evaluated in this study. LV size and function were assessed in a short-axis plane. Segmental radial strain and strain rate and global circumferential strain were measured using a 2D echocardiographic speckle-tracking algorithm (GE EchoPAC). Groups were compared using Bonferroni t-tests. Influences of heart rate and body weight were explored with linear regression. The MR group had significantly greater mean values for heart rate, LV size, and LV systolic function. Specifically, LV diastolic diameter, diastole area, shortening fraction, averaged peak systolic and early diastolic radial strain, global circumferential strain, and averaged radial strain rate were significantly greater in the MR group (p < 0.015 to p < 0.001). Strain was unrelated to weight, but weakly correlated with heart rate. Similar to conventional indices, Stage B2 dogs with MR demonstrate hyperdynamic deformation in the short-axis plane. Short-axis strain variables measured by 2D speckle tracking are greater than for controls of similar age and weight. These results imply either preserved LV systolic function or that LV dysfunction is masked by altered ventricular loading. Copyright © 2012 Elsevier B.V. All rights reserved.

Is Borg's perceived exertion scale a useful indicator of muscular and cardiovascular load in blue-collar workers with lifting tasks? A cross-sectional workplace study.

PubMed

Jakobsen, Markus Due; Sundstrup, Emil; Persson, Roger; Andersen, Christoffer H; Andersen, Lars L

2014-02-01

To investigate associations between perceived exertion and objectively assessed muscular and cardiovascular load during a full working day among workers with manual lifting tasks. A total of 159 men and 41 women from 14 workplaces with manual lifting tasks participated. Participants reported perceived exertion (BORG-CR10) at midday and after work. Surface electromyography of the thigh, lower back and neck muscles were normalized to isometric voluntary contractions (MVC) to express relative muscle load during the day. Cardiovascular load was measured with electrocardiography and calculated as the average percentage of the heart rate reserve capacity (((heart rate during work - resting heart rate) / (maximum heart rate - resting heart rate)) * 100) during the day. Using linear regression, significant but weak associations (β < 0.23) were observed between perceived exertion and (1) high muscle activity (>60% of MVC) of the neck muscles and (2) inactivity (<1% of MVC) of the thigh muscles and (3) cardiovascular load, respectively. Using logistic regression, perceived exertion ≥4 (high exertion), referencing <4 (low-to-moderate exertion), was related to high activity of the trapezius muscle [OR 18 (95% CI 2-143)], i.e., the odds for experiencing high exertion during work increased 18-fold for each percentage increase in time above 60% MVC. During a full working day among blue-collar workers with lifting tasks, high neck muscle activity increases the odds for experiencing high perceived physical exertion. Perceived exertion of at least 4 on the BORG CR10 scale appears to be a good indicator that high muscular loading occurs.

Comparison of Ventilatory Measures and 20 km Time Trial Performance.

PubMed

Peveler, Willard W; Shew, Brandy; Johnson, Samantha; Sanders, Gabe; Kollock, Roger

2017-01-01

Performance threshold measures are used to predict cycling performance. Previous research has focused on long time trials (≥ 40 km) using power at ventilatory threshold and respiratory threshold to estimate time trial performance. As intensity greatly differs during shorter time trails applying findings from longer time trials may not be appropriate. The use of heart rate measures to determine 20 km time trial performance has yet to be examined. The purpose of this study was to determine the effectiveness of heart rate measures at ventilatory threshold (VE/VO 2 Plotted and VT determined by software) and respiratory threshold (RER of 0.95, 1.00, and 1.05) to predict 20 km time trial performance. Eighteen cyclists completed a VO 2max protocol and two 20 km time trials. Average heart rates from 20 km time trials were compared with heart rates from performance threshold measures (VT plotted, VT software, and an RER at 0.95, 1.00, and 1.05) using repeated measures ANOVA. Significance was set a priori at P ≤ 0.05. The only measure not found to be significantly different in relation to time trial performance was HR at an RER of 1.00 (166.61±12.70 bpm vs. 165.89 ± 9.56 bpm, p = .671). VT plotting and VT determined by software were found to underestimate time trial performance by 3% and 8% respectively. From these findings it is recommended to use heart rate at a RER of 1.00 in order to determine 20 km time trial intensity.

Determination of Anaerobic Threshold by Heart Rate or Heart Rate Variability using Discontinuous Cycle Ergometry.

PubMed

Park, Sung Wook; Brenneman, Michael; Cooke, William H; Cordova, Alberto; Fogt, Donovan

The purpose was to determine if heart rate (HR) and heart rate variability (HRV) responses would reflect anaerobic threshold (AT) using a discontinuous, incremental, cycle test. AT was determined by ventilatory threshold (VT). Cyclists (30.6±5.9y; 7 males, 8 females) completed a discontinuous cycle test consisting of 7 stages (6 min each with 3 min of rest between). Three stages were performed at power outputs (W) below those corresponding to a previously established AT, one at W corresponding to AT, and 3 at W above those corresponding to AT. The W at the intersection of the trend lines was considered each metric's "threshold". The averaged stage data for Ve, HR, and time- and frequency-domain HRV metrics were plotted versus W. The W at the "threshold" for the metrics of interest were compared using correlation analysis and paired-sample t -test. In all, several heart rate-related parameters accurately reflected AT with significant correlations (p≤0.05) were observed between AT W and HR, mean RR interval (MRR), low and high frequency spectral energy (LF and HR, respectively), high frequency peak (fHF), and HFxfHF metrics' threshold W (i.e., MRRTW, etc.). Differences in HR or HRV metric threshold W and AT for all subjects were less than 14 W. The steady state data from discontinuous protocols may allow for a true indication of steady-state physiologic stress responses and corresponding W at AT, compared to continuous protocols using 1-2 min exercise stages.

Automated assessment of blood flow in developing embryonic hearts by extending dynamic range of Doppler OCT using a MHz FDML swept laser source (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elahi, Sahar; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

Altered hemodynamics in developing embryonic hearts lead to congenital heart diseases, motivating close monitoring of blood flow over several stages of development. Doppler OCT can assess blood flow in tubular hearts, but the maximum velocity increases drastically during the period of cardiac cushion (valve precursors) formation. Therefore, the limited dynamic range of Doppler OCT velocity measurement makes it difficult to conduct longitudinal studies without phase wrapping at high velocities or loss of sensitivity to slow velocities. We have built a high-speed OCT system using an FDML laser (Optores GmbH, Germany) at a sweep rate of 1.68 MHz (axial resolution - 12 μm, sensitivity - 105 dB, phase stability - 17 mrad). The speed of this OCT system allows us to acquire high-density B-scans to obtain an extended velocity dynamic range without sacrificing the frame rate. The extended dynamic range within a frame is achieved by varying the A-scan interval at which the phase difference is found, enabling detection of velocities ranging from tens of microns per second to hundreds of mm per second. The extra lines in a frame can also be utilized to improve the structural and Doppler images via complex averaging. In structural images where presence of blood causes additional scattering, complex averaging helps retrieve features located deeper in the tissue. Moreover, high-density frames can be registered to 4D volumes to determine the orthogonal direction of flow and calculate shear stress. In conclusion, our high-speed OCT system will enable automated Doppler imaging of embryonic hearts in cohort studies.

Predictors of intraoperative hypotension and bradycardia.

PubMed

Cheung, Christopher C; Martyn, Alan; Campbell, Norman; Frost, Shaun; Gilbert, Kenneth; Michota, Franklin; Seal, Douglas; Ghali, William; Khan, Nadia A

2015-05-01

Perioperative hypotension and bradycardia in the surgical patient are associated with adverse outcomes, including stroke. We developed and evaluated a new preoperative risk model in predicting intraoperative hypotension or bradycardia in patients undergoing elective noncardiac surgery. Prospective data were collected in 193 patients undergoing elective, noncardiac surgery. Intraoperative hypotension was defined as systolic blood pressure <90 mm Hg for >5 minutes or a 35% decrease in the mean arterial blood pressure. Intraoperative bradycardia was defined as a heart rate of <60 beats/min for >5 minutes. A logistic regression model was developed for predicting intraoperative hypotension or bradycardia with bootstrap validation. Model performance was assessed using area under the receiver operating curves and Hosmer-Lemeshow tests. A total of 127 patients developed hypotension or bradycardia. The average age of participants was 67.6 ± 11.3 years, and 59.1% underwent major surgery. A final 5-item score was developed, including preoperative Heart rate (<60 beats/min), preoperative hypotension (<110/60 mm Hg), Elderly age (>65 years), preoperative renin-Angiotensin blockade (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or beta-blockers), Revised cardiac risk index (≥3 points), and Type of surgery (major surgery), entitled the "HEART" score. The HEART score was moderately predictive of intraoperative bradycardia or hypotension (odds ratio, 2.51; 95% confidence interval, 1.79-3.53; C-statistic, 0.75). Maximum points on the HEART score were associated with an increased likelihood ratio for intraoperative bradycardia or hypotension (likelihood ratio, +3.64). The 5-point HEART score was predictive of intraoperative hypotension or bradycardia. These findings suggest a role for using the HEART score to better risk-stratify patients preoperatively and may help guide decisions on perioperative management of blood pressure and heart rate-lowering medications and anesthetic agents. Copyright © 2015 Elsevier Inc. All rights reserved.

Routine physiotherapy does not induce a cardiorespiratory training effect post-stroke, regardless of walking ability.

PubMed

Kuys, Suzanne; Brauer, Sandra; Ada, Louise

2006-12-01

Cardiorespiratory fitness is increasingly being recognized as an impairment requiring physiotherapy intervention after stroke. The present study seeks to investigate if routine physiotherapy treatment is capable of inducing a cardiorespiratory training effect and if stroke patients attending physiotherapy who are unable to walk experience less cardiorespiratory stress during physiotherapy when compared to those who are able to walk. A descriptive, observational study, with heart rate monitoring and video-recording of physiotherapy rehabilitation, was conducted. Thirty consecutive stroke patients from a geriatric and rehabilitation unit of a tertiary metropolitan hospital, admitted for rehabilitation, and requiring physiotherapy were included in the study. The main measures of the study were duration (time) and intensity (percentage of heart rate reserve) of standing and walking activities during physiotherapy rehabilitation for non-walking and walking stroke patients. Stroke patients spent an average of 21 minutes participating in standing and walking activities that were capable of inducing a cardiorespiratory training effect. Stroke patients who were able to walk spent longer in these activities during physiotherapy rehabilitation than non-walking stroke patients (p < 0.05). An average intensity of 24% heart rate reserve (HRR) during standing and walking activities was insufficient to result in a cardiorespiratory training effect, with a maximum of 35% achieved for the stroke patients able to walk and 30% for those unable to walk. Routine physiotherapy rehabilitation had insufficient duration and intensity to result in a cardiorespiratory training effect in our group of stroke patients.

Analysis of the characteristics of competitive badminton

PubMed Central

Cabello, M; Gonzalez-Badillo, J

2003-01-01

Objective: To describe the characteristics of badminton in order to determine the energy requirements, temporal structure, and movements in the game that indicate performance level. To use the findings to plan training with greater precision. Methods: Eleven badminton players (mean (SD) age 21.8 (3.26) years) with international experience from four different countries (France, Italy, Spain, and Portugal) were studied. Two of the Spanish players were monitored in several matches, giving a total of 14 samples, all during the 1999 Spanish International Tournament. Blood lactate concentration was measured with a reflective photometer. Maximum and average heart rates were recorded with a heart rate monitor. Temporal structure and actions during the matches were determined from video recordings. All variables were measured during and after the game and later analysed using a descriptive study. Results: The results confirmed the high demands of the sport, with a maximum heart rate of 190.5 beats/min and an average of 173.5 beats/min during matches over 28 minutes long and performance intervals of 6.4 seconds and rest time of 12.9 seconds between exchanges. Conclusions: The results suggest that badminton is characterised by repetitive efforts of alactic nature and great intensity which are continuously performed throughout the match. An awareness of these characteristics, together with data on the correlations between certain actions such as unforced errors and winning shots and the final result of the match, will aid in more appropriate planning and monitoring of specific training. PMID:12547746

Nicotine delivery and pharmacologic response from Verve, an oral nicotine delivery product☆

PubMed Central

Koszowski, Bartosz; Viray, Lauren C.; Stanfill, Stephen B.; Lisko, Joseph G.; Rosenberry, Zach R.; Potts, Jennifer L.; Pickworth, Wallace B.

2016-01-01

Verve, an oral nicotine delivery product (ONDP), was introduced by Nu Mark (Altria Client Group, Richmond VA) for smokers to use in places where smoking is prohibited. This study assessed the effect of this ONDP on plasma nicotine levels, heart rate, product satisfaction, and ability to suppress smoking urge and cigarette cravings. Thirteen daily cigarette smokers [8 men and 5 women; average age 33.4 years] attended two laboratory sessions, one occurred after overnight tobacco abstinence. Plasma samples were collected before and after ONDP use and measured for nicotine. In non-abstinent smokers, mean plasma nicotine levels increased from 18.3 to 21.0 ng/mL. In abstinent smokers, average nicotine levels increased from 3.1 to 4.5 ng/mL. After overnight tobacco abstinence, ONDP use significantly (p < 0.01) increased heart rate from 69 beats per minute (bpm) to 75 bpm; while urge to smoke decreased significantly (p < 0.01) from a score of 8.6 to 4.9. Participants indicated moderate product satisfaction that was not changed by tobacco abstinence. Analysis of unused ONDP revealed total nicotine levels of 1.68 ± 0.09 mg/disc. Spent ONDP discs were also analyzed to determine % nicotine liberated during chewing; results were 80% in the non-abstinent and 82% in the abstinent conditions (ns). Our study results indicate that ONDP use can increase plasma nicotine levels and heart rate and reduce cigarette cravings in abstinent smokers. PMID:26096037

Nicotine delivery and pharmacologic response from Verve, an oral nicotine delivery product.

PubMed

Koszowski, Bartosz; Viray, Lauren C; Stanfill, Stephen B; Lisko, Joseph G; Rosenberry, Zach R; Potts, Jennifer L; Pickworth, Wallace B

2015-09-01

Verve, an oral nicotine delivery product (ONDP), was introduced by Nu Mark (Altria Client Group, Richmond VA) for smokers to use in places where smoking is prohibited. This study assessed the effect of this ONDP on plasma nicotine levels, heart rate, product satisfaction, and ability to suppress smoking urge and cigarette cravings. Thirteen daily cigarette smokers [8 men and 5 women; average age 33.4years] attended two laboratory sessions, one occurred after overnight tobacco abstinence. Plasma samples were collected before and after ONDP use and measured for nicotine. In non-abstinent smokers, mean plasma nicotine levels increased from 18.3 to 21.0ng/mL. In abstinent smokers, average nicotine levels increased from 3.1 to 4.5ng/mL. After overnight tobacco abstinence, ONDP use significantly (p<0.01) increased heart rate from 69beats per minute (bpm) to 75bpm; while urge to smoke decreased significantly (p<0.01) from a score of 8.6 to 4.9. Participants indicated moderate product satisfaction that was not changed by tobacco abstinence. Analysis of unused ONDP revealed total nicotine levels of 1.68±0.09mg/disc. Spent ONDP discs were also analyzed to determine % nicotine liberated during chewing; results were 80% in the non-abstinent and 82% in the abstinent conditions (ns). Our study results indicate that ONDP use can increase plasma nicotine levels and heart rate and reduce cigarette cravings in abstinent smokers. Copyright © 2015 Elsevier Inc. All rights reserved.

MEASUREMENT OF ENERGY EXPENDITURE WHILE PLAYING EXERGAMES AT A SELF-SELECTED INTENSITY

PubMed Central

Haddock, Bryan, L.; Jarvis, Sarah; Klug, Nicholas, R; Gonzalez, Tarah; Barsaga, Bryan; Siegel, Shannon, R.; Wilkin, Linda, D.

2018-01-01

Exergames have been suggested as a possible alternative to traditional exercise in the general population. The purpose of this study was to examine the heart rate (HR) and energy expenditure (EE) of young adults playing several different exergames, while self-selecting the component of the game to play and the intensity. A total of 117 participants, 18–35 years of age, were evaluated on one of four active video games. Participants were free to choose any component of the given game to play and they played at a self-selected intensity. The average HR and EE during the individual games were compared to resting conditions and to the American College of Sports Medicine (ACSM) guidelines. The HR and EE increased above resting conditions during each game (p<0.05). When the results of all games were combined, the HR was 125.4 ± 20.0 bpm and the average EE was 6.7 ± 2.1 kcal/min. This HR represents an average percent of heart rate reserve of 44.6 ± 14.1, high enough to be considered moderate intensity exercise. If performed for 30 minutes a day, five days per week, the average EE would be 1,005 kcals, enough to meet the ACSM recommendations for weekly EE. Therefore, at least some exergames could be a component of an exercise program. PMID:29354191

A preliminary study of a running speed based heart rate prediction during an incremental treadmill exercise.

PubMed

Dae-Geun Jang; Byung-Hoon Ko; Sub Sunoo; Sang-Seok Nam; Hun-Young Park; Sang-Kon Bae

2016-08-01

This preliminary study investigates feasibility of a running speed based heart rate (HR) prediction. It is basically motivated from the assumption that there is a significant relationship between HR and the running speed. In order to verify the assumption, HR and running speed data from 217 subjects of varying aerobic capabilities were simultaneously collected during an incremental treadmill exercise. A running speed was defined as a treadmill speed and its corresponding heart rate was calculated by averaging the last one minute HR values of each session. The feasibility was investigated by assessing a correlation between the heart rate and the running speed using inter-subject (between-subject) and intra-subject (within-subject) datasets with regression orders of 1, 2, 3, and 4, respectively. Furthermore, HR differences between actual and predicted HRs were also employed to investigate the feasibility of the running speed in predicting heart rate. In the inter-subject analysis, a strong positive correlation and a reasonable HR difference (r = 0.866, 16.55±11.24 bpm @ 1st order; r = 0.871, 15.93±11.49 bpm @ 2nd order; r = 0.897, 13.98±10.80 bpm @ 3rd order; and r = 0.899, 13.93±10.64 bpm @ 4th order) were obtained, and a very high positive correlation and a very low HR difference (r = 0.978, 6.46±3.89 bpm @ 1st order; r = 0.987, 5.14±2.87 bpm @ 2nd order; r = 0.996, 2.61±2.03 bpm @ 3rd order; and r = 0.997, 2.04±1.73 bpm @ 4th order) were obtained in the intra-subject analysis. It can therefore be concluded that 1) heart rate is highly correlated with a running speed; 2) heart rate can be approximately estimated by a running speed with a proper statistical model (e.g., 3rd-order regression); and 3) an individual HR-speed calibration process may improve the prediction accuracy.

General anesthesia suppresses normal heart rate variability in humans

NASA Astrophysics Data System (ADS)

Matchett, Gerald; Wood, Philip

2014-06-01

The human heart normally exhibits robust beat-to-beat heart rate variability (HRV). The loss of this variability is associated with pathology, including disease states such as congestive heart failure (CHF). The effect of general anesthesia on intrinsic HRV is unknown. In this prospective, observational study we enrolled 100 human subjects having elective major surgical procedures under general anesthesia. We recorded continuous heart rate data via continuous electrocardiogram before, during, and after anesthesia, and we assessed HRV of the R-R intervals. We assessed HRV using several common metrics including Detrended Fluctuation Analysis (DFA), Multifractal Analysis, and Multiscale Entropy Analysis. Each of these analyses was done in each of the four clinical phases for each study subject over the course of 24 h: Before anesthesia, during anesthesia, early recovery, and late recovery. On average, we observed a loss of variability on the aforementioned metrics that appeared to correspond to the state of general anesthesia. Following the conclusion of anesthesia, most study subjects appeared to regain their normal HRV, although this did not occur immediately. The resumption of normal HRV was especially delayed on DFA. Qualitatively, the reduction in HRV under anesthesia appears similar to the reduction in HRV observed in CHF. These observations will need to be validated in future studies, and the broader clinical implications of these observations, if any, are unknown.

Hemodynamic responses to dexmedetomidine in critically injured intubated pediatric burned patients: a preliminary study.

PubMed

Shank, Erik S; Sheridan, Robert L; Ryan, Colleen M; Keaney, Timothy J; Martyn, J A Jeevendra

2013-01-01

Because of ineffectiveness and tolerance to benzodiazepines and opioids developing with time, drugs acting via other receptor systems (eg, α-2 agonists) have been advocated in burn patients to improve sedation and analgesia. This study in severely burned pediatric subjects examined the hemodynamic consequences of dexmedetomidine (Dex) administration. Eight intubated patients with ≥20 to 79% TBSA burns were studied between 7 and 35 days after injury. After baseline measurements of mean arterial blood pressure and heart rhythm were taken, each patient received a 1.0 µg/kg bolus of Dex followed by an ascending dose infusion protocol (0.7-2.5 µg/kg/hr), with each dose administered for 15 minutes. There was significant hypotension (27±7.5%, average drop in mean arterial pressure [MAP] ± SD), and a decrease in heart rate (HR; 19% ± 7, average drop in HR ± SD). The average HR decreased from 146 beats per minute to 120. No bradycardia (HR < 60) or heart blocks were observed. In three patients, the MAP decreased to <50mm Hg with the bolus dose of Dex. Of the remaining five patients, three patients completed the study receiving the highest infusion dose of Dex (2.5 µg/kg/hr), whereas in 2 patients the infusion part of the study was begun, but the study was stopped due to persistent hypotension (MAP < 50mm Hg). These observations indicate that a bolus dose of Dex (1.0 µg/kg for 10 minutes) and high infusion rates may require fluid resuscitation or vasopressor support to maintain normotension in critically injured pediatric burn patients.

Compassion satisfaction, burnout, and secondary traumatic stress in heart and vascular nurses.

PubMed

Young, Jennifer L; Derr, Denise M; Cicchillo, Vikki J; Bressler, Sonya

2011-01-01

Objectives for this project were to determine the prevalence of compassion satisfaction (CS), burnout, and secondary traumatic stress (STS) in heart and vascular nurses to confirm whether differences exist between intensive care and intermediate care nurses. The Professional Quality of Life Scale Compassion Satisfaction and Compassion Fatigue: Version 5 developed by Stamm (2009) was used. Results showed that nurses who work in the heart and vascular intermediate care unit had average to high scores of CS, low to average levels of burnout, and low to average levels of STS. Nurses who work in the heart and vascular intensive care unit had average to high levels of CS, low to average levels of burnout, and low to average levels of STS. These findings suggest that leadership should be aware of the prevalence of STS and burnout in heart and vascular nurses. Raising awareness of STS and burnout in intensive care and intermediate care nurses can help in targeting more specific strategies that may prevent the onset of developing these symptoms.

Microwave influence on the isolated heart function. 1: Effect of modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakhomov, A.G.; Dubovick, B.V.; Degtyariov, I.G.

1995-09-01

Dependence of the microwave effect on modulation parameters (pulse width, duty ratio, and peak intensity) was studied in an isolated frog auricle preparation. The rate and amplitude of spontaneous auricle twitches were measured during and after a 2 min exposure to 915 or 885 MHz microwaves and were compared to preexposure values. The studied ranges of modulation parameters were: pulse width, 10{sup {minus}6}--10{sup {minus}2} s; duty ratio, 7:100000, and peak specific absorption rate, 100--3,000 W/kg. Combinations of the parameters were chosen by chance, and about 400 various exposure regimes were tested. The experiments established that no regime was effective unlessmore » the average microwave power was high enough to induce preparation heating (0.1--0.4 C). The twitch rate instantly increased, and the amplitude decreased, as the temperature rose; similar changes could be induced by equivalent conventional heating. the data provide evidence that the effect of short-term microwave exposure on the isolated heart pacemaker and contractile functions depends on pulse modulation just as much as modulation determines the average absorbed power. These functions demonstrated no specific dependence on exposure parameters such as frequency or power windows.« less

A study on reducing the absorption of lidocaine from the airway in cats.

PubMed

Chen, Yunfeng; Zeng, Yiming; Zhang, Yin

2017-08-01

To determine if the combination of lidocaine with epinephrine or gamma globulin would decrease the rate or reduce the amount of local absorption of lidocaine through the airway. Twenty adult male cats were randomly and evenly distributed into four groups: 1) Group LG: lidocaine administered with gamma globulin; 2) Group LS: lidocaine administered with physiological saline); 3) Group LE: lidocaine administered with epinephrine; 4) Group C: control group. Invasive blood pressure, heart rate, and concentration of lidocaine were recorded before and after administration. The peak of plasma concentrations appeared difference (Group LG: 1.39 ± 0.23 mg/L; Group LS: 1.47 ± 0.29 mg/L and Group LE: 0.99 ± 0.08 mg/L). Compared to Group C, there were significant differences in the average heart rate of Groups LG, LS, and LE (P < 0.05). The average systolic blood pressures were significantly different when each group was compared to Group C (P < 0.05). The biological half-life, AUC0-120, peak time, and half-life of absorption among the three groups have not presented statistically significant differences (P > 0.05). Administering lidocaine in combination with gamma globulin through airway causes significant decrease the rate and reduce the amount of local absorption of lidocaine in cats.

Robust detection of heart beats in multimodal records using slope- and peak-sensitive band-pass filters.

PubMed

Pangerc, Urška; Jager, Franc

2015-08-01

In this work, we present the development, architecture and evaluation of a new and robust heart beat detector in multimodal records. The detector uses electrocardiogram (ECG) signals, and/or pulsatile (P) signals, such as: blood pressure, artery blood pressure and pulmonary artery pressure, if present. The base approach behind the architecture of the detector is collecting signal energy (differentiating and low-pass filtering, squaring, integrating). To calculate the detection and noise functions, simple and fast slope- and peak-sensitive band-pass digital filters were designed. By using morphological smoothing, the detection functions were further improved and noise intervals were estimated. The detector looks for possible pacemaker heart rate patterns and repairs the ECG signals and detection functions. Heart beats are detected in each of the ECG and P signals in two steps: a repetitive learning phase and a follow-up detecting phase. The detected heart beat positions from the ECG signals are merged into a single stream of detected ECG heart beat positions. The merged ECG heart beat positions and detected heart beat positions from the P signals are verified for their regularity regarding the expected heart rate. The detected heart beat positions of a P signal with the best match to the merged ECG heart beat positions are selected for mapping into the noise and no-signal intervals of the record. The overall evaluation scores in terms of average sensitivity and positive predictive values obtained on databases that are freely available on the Physionet website were as follows: the MIT-BIH Arrhythmia database (99.91%), the MGH/MF Waveform database (95.14%), the augmented training set of the follow-up phase of the PhysioNet/Computing in Cardiology Challenge 2014 (97.67%), and the Challenge test set (93.64%).

Patients’ Heart Monitoring System Based on Wireless Sensor Network

NASA Astrophysics Data System (ADS)

Sollu, T. S.; Alamsyah; Bachtiar, M.; Sooai, A. G.

2018-04-01

Wireless sensor network (WSN) has been utilized to support the health field such as monitoring the patient’s heartbeat. Heart health monitoring is essential in maintaining health, especially in the elderly. Such an arrangement is needed to understand the patient’s heart characteristics. The increasing number of patients certainly will enhance the burdens of doctors or nurses in dealing with the condition of the patients. Therefore, required a solution that could help doctors or nurses in monitoring the progress of patients’ health at a real time. This research proposes a design and application of a patient heart monitoring system based on WSN. This system with using electrocardiograph (ECG) mounted on the patients’ body and sent to the server through the ZigBee. The results indicated that the retrieval of data for 15 seconds in male patients, with the age of 25 years was 17 times rate or equal to 68 bpm. For 884 data packets sent for 15 minutes using ZigBee produce a data as much as 4488 bytes, throughput of 2.39 Kbps, and 0.24486 seconds of average delay. The measurement of the communication coverage based on the open space conditions within 15 seconds through ZigBee resulting throughput value of 4.19 Kbps, packet loss of 0 %, and 6.667 seconds of average delay. While, the measurement of communication range based on closed space condition through ZigBee resulting throughput of 4.27 Kbps, packet loss of 0 %, and 6.55 seconds of average delay.

Individually Coded Telemetry: a Tool for Studying Heart Rate and Behaviour in Reindeer Calves

PubMed Central

Eloranta, E; Norberg, H; Nilsson, A; Pudas, T; Säkkinen, H

2002-01-01

The aim of the study was to test the performance of a silver wire modified version of the coded telemetric heart rate monitor Polar Vantage NV™ (PVNV) and to measure heart rate (HR) in a group of captive reindeer calves during different behaviour. The technical performance of PVNV HR monitors was tested in cold conditions (-30°C) using a pulse generator and the correlation between generated pulse and PVNV values was high (r = 0.9957). The accuracy was tested by comparing the HR obtained with the PVNV monitor with the standard ECG, and the correlation was significant (r = 0.9965). Both circadian HR and HR related to behavioural pattern were recorded. A circadian rhythm was observed in the HR in reindeer with a minimum during night and early morning hours and maximum at noon and during the afternoon, the average HR of the reindeer calves studied being 42.5 beats/min in February. The behaviour was recorded by focal individual observations and the data was synchronized with the output of the HR monitors. Running differed from all other behavioural categories in HR. Inter-individual differences were seen expressing individual responses to external and internal stimuli. The silver wire modified Polar Vantage NV™ provides a suitable and reliable tool for measuring heart rate in reindeer, also in natural conditions. PMID:12564543

Effects of moderate and heavy endurance exercise on nocturnal HRV.

PubMed

Hynynen, E; Vesterinen, V; Rusko, H; Nummela, A

2010-06-01

This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effects on autonomic modulation after exercises, which may give useful information on the extent of exercise-induced nocturnal autonomic modulation and disturbance to the homeostasis.

Adaptive motion artifact reducing algorithm for wrist photoplethysmography application

NASA Astrophysics Data System (ADS)

Zhao, Jingwei; Wang, Guijin; Shi, Chenbo

2016-04-01

Photoplethysmography (PPG) technology is widely used in wearable heart pulse rate monitoring. It might reveal the potential risks of heart condition and cardiopulmonary function by detecting the cardiac rhythms in physical exercise. However the quality of wrist photoelectric signal is very sensitive to motion artifact since the thicker tissues and the fewer amount of capillaries. Therefore, motion artifact is the major factor that impede the heart rate measurement in the high intensity exercising. One accelerometer and three channels of light with different wavelengths are used in this research to analyze the coupled form of motion artifact. A novel approach is proposed to separate the pulse signal from motion artifact by exploiting their mixing ratio in different optical paths. There are four major steps of our method: preprocessing, motion artifact estimation, adaptive filtering and heart rate calculation. Five healthy young men are participated in the experiment. The speeder in the treadmill is configured as 12km/h, and all subjects would run for 3-10 minutes by swinging the arms naturally. The final result is compared with chest strap. The average of mean square error (MSE) is less than 3 beats per minute (BPM/min). Proposed method performed well in intense physical exercise and shows the great robustness to individuals with different running style and posture.

Heart-rate monitoring by air pressure and causal analysis

NASA Astrophysics Data System (ADS)

Tsuchiya, Naoki; Nakajima, Hiroshi; Hata, Yutaka

2011-06-01

Among lots of vital signals, heart-rate (HR) is an important index for diagnose human's health condition. For instance, HR provides an early stage of cardiac disease, autonomic nerve behavior, and so forth. However, currently, HR is measured only in medical checkups and clinical diagnosis during the rested state by using electrocardiograph (ECG). Thus, some serious cardiac events in daily life could be lost. Therefore, a continuous HR monitoring during 24 hours is desired. Considering the use in daily life, the monitoring should be noninvasive and low intrusive. Thus, in this paper, an HR monitoring in sleep by using air pressure sensors is proposed. The HR monitoring is realized by employing the causal analysis among air pressure and HR. The causality is described by employing fuzzy logic. According to the experiment on 7 males at age 22-25 (23 on average), the correlation coefficient against ECG is 0.73-0.97 (0.85 on average). In addition, the cause-effect structure for HR monitoring is arranged by employing causal decomposition, and the arranged causality is applied to HR monitoring in a setting posture. According to the additional experiment on 6 males, the correlation coefficient is 0.66-0.86 (0.76 on average). Therefore, the proposed method is suggested to have enough accuracy and robustness for some daily use cases.

Measuring high pressure baroreceptor sensitivity in the rat.

PubMed

Shiry, L J; Hamlin, R L

2011-01-01

The high pressure baroreceptor reflex rapidly buffers changes in systemic arterial pressure in response to postural changes, altered gravitational conditions, diseases, and pharmacological agents. Drug-induced exaggeration of changes in heart rate and in systemic arterial pressure is a leading cause of adverse events and of patients terminating use of drugs, particularly in the aging population. This paper presents a facile method for monitoring the high pressure baroreceptor reflex in rats, and presents an alternative to quantifying the magnitude of this reflex using 2 dependent variables, heart rate and systemic arterial pressure, rather than merely change in heart rate. Twenty-four rats were allocated to 3 groups: group I anesthetized with 100mg/kg thiopental, group II anesthetized with 2% isoflurane given by inhalation, group III anesthetized with thiopental but pretreated for 2weeks with 2μg/kg aldosterone given SQ bid. After induction to anesthesia, hair was clipped from the ventral aspect of the neck, and petrolatum was applied to the skin to permit an air-tight seal with a glass funnel attached to a source of variable and controllable negative pressure. Systemic arterial pressure, ECG, heart rate, and a force of suction applied to the neck were all recorded continuously. After baseline recordings, a force of -20mmHg was applied for 20s over the carotid artery. In rats receiving thiopental, the average changes in heart rate and systemic arterial pressure following the application of -20mmHg neck suction were 30±11bpm and 45±14mmHg, respectively. The ratios of change in heart and change in systemic arterial pressure to application of negative force over the carotid sinus are 1.5±0.6bpm/mmHg and 0.7±04mmHg/mmHg, respectively. Mean values for heart rate and for mean systemic arterial pressure during baseline and after application of neck suction for 20s showed little to no decrease (i.e., blunting) in rats anesthetized with isoflurane or pretreated with aldosterone. Thus this methodology was able to detect, in rats, blunting of baroreceptor function for at least 2 perturbations of this important homeostatic control system. Copyright © 2011. Published by Elsevier Inc.

Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study.

PubMed

Resnick, Portia B

2016-03-01

Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject's heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session.

Monitoring training status with HR measures: do all roads lead to Rome?

PubMed Central

Buchheit, Martin

2014-01-01

Measures of resting, exercise, and recovery heart rate are receiving increasing interest for monitoring fatigue, fitness and endurance performance responses, which has direct implications for adjusting training load (1) daily during specific training blocks and (2) throughout the competitive season. However, these measures are still not widely implemented to monitor athletes' responses to training load, probably because of apparent contradictory findings in the literature. In this review I contend that most of the contradictory findings are related to methodological inconsistencies and/or misinterpretation of the data rather than to limitations of heart rate measures to accurately inform on training status. I also provide evidence that measures derived from 5-min (almost daily) recordings of resting (indices capturing beat-to-beat changes in heart rate, reflecting cardiac parasympathetic activity) and submaximal exercise (30- to 60-s average) heart rate are likely the most useful monitoring tools. For appropriate interpretation at the individual level, changes in a given measure should be interpreted by taking into account the error of measurement and the smallest important change of the measure, as well as the training context (training phase, load, and intensity distribution). The decision to use a given measure should be based upon the level of information that is required by the athlete, the marker's sensitivity to changes in training status and the practical constrains required for the measurements. However, measures of heart rate cannot inform on all aspects of wellness, fatigue, and performance, so their use in combination with daily training logs, psychometric questionnaires and non-invasive, cost-effective performance tests such as a countermovement jump may offer a complete solution to monitor training status in athletes participating in aerobic-oriented sports. PMID:24578692

The Effect of Adenotonsillectomy for Childhood Sleep Apnea on Cardiometabolic Measures.

PubMed

Quante, Mirja; Wang, Rui; Weng, Jia; Rosen, Carol L; Amin, Raouf; Garetz, Susan L; Katz, Eliot; Paruthi, Shalini; Arens, Raanan; Muzumdar, Hiren; Marcus, Carole L; Ellenberg, Susan; Redline, Susan

2015-09-01

Obstructive sleep apnea syndrome (OSAS) has been associated with cardiometabolic disease in adults. In children, this association is unclear. We evaluated the effect of early adenotonsillectomy (eAT) for treatment of OSAS on blood pressure, heart rate, lipids, glucose, insulin, and C-reactive protein. We also analyzed whether these parameters at baseline and changes at follow-up correlated with polysomnographic indices. Data collected at baseline and 7-mo follow-up were analyzed from a randomized controlled trial, the Childhood Adenotonsillectomy Trial (CHAT). Clinical referral setting from multiple centers. There were 464 children, ages 5 to 9.9 y with OSAS without severe hypoxemia. Randomization to eAT or Watchful Waiting with Supportive Care (WWSC). There was no significant change of cardiometabolic parameters over the 7-mo interval in the eAT group compared to WWSC group. However, overnight heart rate was incrementally higher in association with baseline OSAS severity (average heart rate increase of 3 beats per minute [bpm] for apnea-hypopnea index [AHI] of 2 versus 10; [standard error = 0.60]). Each 5-unit improvement in AHI and 5 mmHg improvement in peak end-tidal CO2 were estimated to reduce heart rate by 1 and 1.5 bpm, respectively. An increase in N3 sleep also was associated with small reductions in systolic blood pressure percentile. There is little variation in standard cardiometabolic parameters in children with obstructive sleep apnea syndrome (OSAS) but without severe hypoxemia at baseline or after intervention. Of all measures, overnight heart rate emerged as the most sensitive parameter of pediatric OSAS severity. Clinicaltrials.gov (#NCT00560859). © 2015 Associated Professional Sleep Societies, LLC.

A comparison of 2 circuit exercise training techniques for eliciting matched metabolic responses in persons with paraplegia.

PubMed

Nash, Mark S; Jacobs, Patrick L; Woods, Jeffrey M; Clark, James E; Pray, Tanya A; Pumarejo, Alex E

2002-02-01

To test whether acute metabolic (VO(2)), chronotropic (heart rate), and perceptual (rating of perceived exertion; RPE) responses to exercise by persons with paraplegia differ when the exercise is on a multistation isoinertial exercise system (MultiGym) or on a customized system of Thera-Band resistance bands (ElasticGym). Within-subjects comparison of 2 treatments. Academic medical center. Sixteen men and 1 woman with complete paraplegia (T4-L1), as defined by the American Spinal Injury Association. A circuit resistance training (CRT) program for persons with paraplegia was adapted to both a MultiGym and a customized ElasticGym. Exercises used for training and testing used 6 resistance maneuvers at 50% of the 1-repetition maximum (1-RM), with interposed rapid arm spinning. Subjects were habituated to both conditions for 2 weeks before testing on randomized nonconsecutive days. VO(2) (L/min) was measured by portable spirometry, heart rate (beats/min) by a chest strap monitor, and RPE by the Borg Scale of Perceived Exertion (6-20). No significant effects of test condition on average VO(2) or heart rate were observed, with differences between conditions reflecting only .08L/min and 6.4 beats/min, respectively. Average RPE was significantly higher in testing under the ElasticGym condition (P < .05). CRT on a customized ElasticGym system elicited acute metabolic and chronotropic responses that did not differ from responses to exercise on a MultiGym, though RPE was greater with the ElasticGym. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Quantifying Training Loads in Contemporary Dance.

PubMed

Jeffries, Annie C; Wallace, Lee; Coutts, Aaron J

2017-07-01

To describe the training demands of contemporary dance and determine the validity of using the session rating of perceived exertion (sRPE) to monitor exercise intensity and training load in this activity. In addition, the authors examined the contribution of training (ie, accelerometry and heart rate) and non-training-related factors (ie, sleep and wellness) to perceived exertion during dance training. Training load and ActiGraphy for 16 elite amateur contemporary dancers were collected during a 49-d period, using heart-rate monitors, accelerometry, and sRPE. Within-individual correlation analysis was used to determine relationships between sRPE and several other measures of training intensity and load. Stepwise multiple regressions were used to determine a predictive equation to estimate sRPE during dance training. Average weekly training load was 4283 ± 2442 arbitrary units (AU), monotony 2.13 ± 0.92 AU, strain 10677 ± 9438 AU, and average weekly vector magnitude load 1809,707 ± 1015,402 AU. There were large to very large within-individual correlations between training-load sRPE and various other internal and external measures of intensity and load. The stepwise multiple-regression analysis also revealed that 49.7% of the adjusted variance in training-load sRPE was explained by peak heart rate, metabolic equivalents, soreness, motivation, and sleep quality (y = -4.637 + 13.817%HR peak + 0.316 METS + 0.100 soreness + 0.116 motivation - 0.204 sleep quality). The current findings demonstrate the validity of the sRPE method for quantifying training load in dance, that dancers undertake very high training loads, and a combination of training and nontraining factors contribute to perceived exertion in dance training.

Determination of the Metabolic Rate and Work Arduousness Class for Workers in Coal Mines - The Results of in Situ Research

NASA Astrophysics Data System (ADS)

Drenda, Jan; Kułagowska, Ewa; Różański, Zenon; Pach, Grzegorz; Wrona, Paweł; Karolak, Izabela

2017-06-01

Considering different duties and activities among miners working in underground coal mines, their work is connected with variable metabolic rate. Determination of this rate for different workplace was the aim of the research and was the base for set up the work arduousness classes for the workplace (according to the standard PN-EN 27243). The research covered 6 coal mines, 268 workers and 1164 series of measurements. Metabolic rate was established on the base of heart rate obtained from individual pulsometers (according to the standard PN-EN ISO 8996). Measurements were supplemented by poll surveys about worker and thermal environment parameters. The results showed significant variability of average heart rate (from 87 bmp to 100 bpm) with variance coefficient 14%. Mean values of metabolic rate were from 150 W/m2 to 207 W/m2. According to the results, the most common class of work arduousness was at moderate metabolic rate (class 2 - moderate work), however, more intense work was found in headings, especially at " blind end" workplace.

Heart failure and the holidays.

PubMed

Shah, Mahek; Bhalla, Vikas; Patnaik, Soumya; Maludum, Obiora; Lu, Marvin; Figueredo, Vincent M

2016-10-01

Studies suggest increased cardiac morbidity and heart failure exacerbations during winter months with a peak around the holiday season. Major sporting events and intense encounters in sports have been shown to affect cardiovascular outcomes amongst its fans. All patients admitted to Einstein Medical Center between January 1, 2003 and December 31, 2013 with a diagnosis of congestive heart failure were included in the study. They were included on the basis of the presence of an ICD-9CM code representing congestive heart failure as the primary diagnosis. Comparisons were made between the rates of heart failure admissions on the holiday, 4 days following the holiday and the rest of the month for 5 specific days: Christmas day, New Year's day, Independence day, Thanksgiving day and Super Bowl Sunday. Our study included 22,727 heart failure admissions at an average of 5.65 admissions per day. The mean patient age was 68 ± 15 years. There was a significant increase in daily heart failure admissions following Independence day (5.65 vs. 5; p = 0.027) and Christmas day (6.5 vs. 5.5; p = 0.046) when compared to the rest of the month. A history of alcohol abuse or dependence did not correlate with the reported+ rise in heart failure admissions immediately following the holidays. The mean number of daily admissions on the holidays were significantly lower for all holidays compared to the following 4 days. All holidays apart from Super Bowl Sunday demonstrated lower admission rates on the holiday compared to the rest of the month. Christmas and Independence day were associated with increased heart failure admissions immediately following the holidays. The holidays themselves saw lower admission rates. Overeating on holidays, associated emotional stressors, lesser exercise and postponing medical around holidays may be among the factors responsible for the findings.

Towards 24/7 continuous heart rate monitoring.

PubMed

Tarniceriu, Adrian; Parak, Jakub; Renevey, Philippe; Nurmi, Marko; Bertschi, Mattia; Delgado-Gonzalo, Ricard; Korhonen, Ilkka

2016-08-01

Heart rate (HR) and HR variability (HRV) carry rich information about physical activity, mental and physical load, physiological status, and health of an individual. When combined with activity monitoring and personalized physiological modelling, HR/HRV monitoring may be used for monitoring of complex behaviors and impact of behaviors and external factors on the current physiological status of an individual. Optical HR monitoring (OHR) from wrist provides a comfortable and unobtrusive method for HR/HRV monitoring and is better adhered by users than traditional ECG electrodes or chest straps. However, OHR power consumption is significantly higher than that for ECG based methods due to the measurement principle based on optical illumination of the tissue. We developed an algorithmic approach to reduce power consumption of the OHR in 24/7 HR trending. We use continuous activity monitoring and a fast converging frequency domain algorithm to derive a reliable HR estimate in 7.1s (during outdoor sports, in average) to 10.0s (during daily life). The method allows >80% reduction in power consumption in 24/7 OHR monitoring when average HR monitoring is targeted, without significant reduction in tracking accuracy.

Diving bradycardia of elderly Korean women divers, haenyeo, in cold seawater: a field report

PubMed Central

LEE, Joo-Young; LEE, Hyo-Hyun; KIM, Siyeon; JANG, Young-Joon; BAEK, Yoon-Jeong; KANG, Kwon-Yong

2015-01-01

The purpose of the present field study was to explore diving patterns and heart rate of elderly Korean women divers (haenyeo) while breath-hold diving in cold seawater. We hypothesized that the decreasing rate in heart rate of elderly haenyeos during breath-hold diving was greater and total diving time was shorter than those of young haenyeos from previous studies. Nine haenyeos participated in a field study [68 ± 10 yr in age, ranged from 56 to 83 yr] at a seawater temperature of 10 to 13 °C. Average total diving time including surface swimming time between dives was 253 ± 73 min (155–341 min). Total frequency of dives was 97 ± 28 times and they dived 23 ± 8 times per hour. All haenyeos showed diving bradycardia with a decreased rate of 20 ± 8% at the bottom time (101 ± 20 bpm) when compared to surface swimming time (125 ± 16 bpm) in the sea. Older haenyeos among the nine elderly haenyeos had shorter diving time, less diving frequencies, and lower heart rate at work (p<0.05). These reductions imply that haenyeos voluntarily adjust their workload along with advancing age and diminished cardiovascular functions. PMID:26632118

Diving bradycardia of elderly Korean women divers, haenyeo, in cold seawater: a field report.

PubMed

Lee, Joo-Young; Lee, Hyo-Hyun; Kim, Siyeon; Jang, Young-Joon; Baek, Yoon-Jeong; Kang, Kwon-Yong

2016-01-01

The purpose of the present field study was to explore diving patterns and heart rate of elderly Korean women divers (haenyeo) while breath-hold diving in cold seawater. We hypothesized that the decreasing rate in heart rate of elderly haenyeos during breath-hold diving was greater and total diving time was shorter than those of young haenyeos from previous studies. Nine haenyeos participated in a field study [68 ± 10 yr in age, ranged from 56 to 83 yr] at a seawater temperature of 10 to 13 °C. Average total diving time including surface swimming time between dives was 253 ± 73 min (155-341 min). Total frequency of dives was 97 ± 28 times and they dived 23 ± 8 times per hour. All haenyeos showed diving bradycardia with a decreased rate of 20 ± 8% at the bottom time (101 ± 20 bpm) when compared to surface swimming time (125 ± 16 bpm) in the sea. Older haenyeos among the nine elderly haenyeos had shorter diving time, less diving frequencies, and lower heart rate at work (p<0.05). These reductions imply that haenyeos voluntarily adjust their workload along with advancing age and diminished cardiovascular functions.

[Heart rate control in chronic heart failure patients received cardiovascular implantable electronic device therapy: effects of optimized medication].

PubMed

Gao, Y; Liang, Y C; Yu, H B; Yan, X L; Xu, B G; Liu, R; Wang, N; Xu, G Q; Wang, Z L

2018-03-24

Objective: To investigate the heart rate control situation of chronic heart failure (CHF) patients who received cardiovascular implantable electronic device (CIED) therapy, and to assess the heart rate control efficacy by optimized medication adjustment. Methods: We performed a perspective study in heart failure with reduced left ventricular ejection fraction (HFrEF) patients who received CIED according to guideline recommendations, patients were enrolled from January 2012 to January 2017. Resting heart rate (RHR) recorded by electrocardiogram after 10 minutes' rest and medication usage within 1 month were recorded at baseline. RHR less than 70 beats per minute (bpm) was regarded as well controlled. β-receptor blockers and (or) ivabradine would be added in patients whose RHR were over 70 bpm. RHR after optimized medication adjustment was recorded during follow-up period. Results: One hundred and fifty patients were included in this study with average RHR (80.6±11.9) bpm. RHR was<70 bpm in 27.3% (41/150) patients at baseline and β-receptor blockers was underused in 80.7% patients (88/109) whose RHR was>70 bpm. The overall RHR decreased to (73.1±10.4) bpm and percent of patients with RHR<70 bpm increased to 70.0% (105/150) after up-titration of β-receptor blockers compared to baseline (χ 2 =52.958, P< 0.001). Ivabradine was added in the rest 45 patients and RHR was<70 bpm in 43 out of 45 patients after ivabradine use. The overall RHR decreased to (67.1±2.7) bpm and percent of RHR<70 bpm significantly increased to 98.7% (148/150) (χ 2 =44.504, P< 0.001 vs. up-titration of β-receptor blockers only). Conclusion: RHR in CHF patients who received CIED therapy is not ideally controlled in this patient cohort, individual up-titration ofβ-receptor blockers and ivabradine use may help to optimize RHR in these patients.

Physiological responses to exergaming after spinal cord injury.

PubMed

Burns, Patricia; Kressler, Jochen; Nash, Mark S

2012-01-01

To investigate whether exergaming satisfies guideline-based intensity standards for exercise conditioning (40%/50% oxygen uptake reserve [VO2R] or heart rate reserve (HRR), or 64%/70% of peak heart rate [HRpeak]) in persons with paraplegia. Nine men and women (18-65 years old) with chronic paraplegia (T1-L1, AIS A-C) underwent intensity-graded arm cycle exercise (AE) to evaluate VO2peak and HRpeak. On 2 randomized nonconsecutive days, participants underwent graded exercise using a custom arm cycle ergometer that controls the video display of a Nintendo Gamecube (GameCycle; Three Rivers Holdings LLC, Mesa, AZ) or 15 minutes of incrementally wrist-weighted tennis gameplay against a televised opponent (XaviX Tennis System; SSD Co Ltd, Kusatsu, Japan). GameCycle exergaming (GCE) resistance settings ≥0.88 Nm evoked on average ≥50% VO2R. During XaviX Tennis System exergaming (XTSE) with wrist weights ≥2 lbs, average VO2 reached a plateau of ~40% VO2R. Measurements of HR were highly variable and reached average values ≥50% HRR during GCE at resistance settings ≥0.88 Nm. During XTSE, average HR did not reach threshold levels based on HRR for any wrist weight (20%-35% HRR). On average, intensity responses to GCE at resistance setting ≥0.88 Nm were sufficient to elicit exercise intensities needed to promote cardiorespiratory fitness in individuals with SCI. The ability of XTSE to elicit cardiorespiratory fitness benefits is most likely limited to individuals with very low fitness levels and may become subminimal with time if used as a conditioning stimulus.

Oxygen saturation in healthy children aged 5 to 16 years residing in Huayllay, Peru at 4340 m.

PubMed

Schult, Sandra; Canelo-Aybar, Carlos

2011-01-01

Hypoxemia is a major life-threatening complication of childhood pneumonia. The threshold points for hypoxemia vary with altitude. However, few published data describe that normal range of variation. The purpose of this study was to establish reference values of normal mean Sao(2) levels and an approximate cutoff point to define hypoxemia for clinical purposes above 4300 meters above sea level (masl). Children aged 5 to 16 yr were examined during primary care visits at the Huayllay Health Center. Huayllay is a rural community located at 4340 m in the province of Pasco in the Peruvian Andes. We collected basic sociodemographic data and evaluated three outcomes: arterial oxygen saturation (Sao(2)) with a pulse oximeter, heart rate, and respiratory rate. Comparisons of main outcomes among age groups (5-6, 7-8, 9-10, 11-12, 13-14, and 15-16 yr) and sex were performed using linear regression models. The correlation of Sao(2) with heart rate and respiration rate was established by Pearson's correlation test. We evaluated 583 children, of whom 386 were included in the study. The average age was 10.3 yr; 55.7% were female. The average Sao(2), heart rate, and respiratory rate were 85.7% (95% CI: 85.2-86.2), 80.4/min (95% CI: 79.0-81.9), and 19.9/min (95% CI: 19.6-20.2), respectively. Sao(2) increased with age (p < 0.001). No differences by sex were observed. The mean minus two standard deviations of Sao(2) (threshold point for hypoxemia) ranged from 73.8% to 81.8% by age group. At 4300 m, the reference values for hypoxemia may be 14.2% lower than at sea level. This difference must be considered when diagnosing hypoxemia or deciding oxygen supplementation at high altitude. Other studies are needed to determine whether this reference value is appropriate for clinical use.

Trends in ischemic heart disease mortality in Korea, 1985-2009: an age-period-cohort analysis.

PubMed

Lee, Hye Ah; Park, Hyesook

2012-09-01

Economic growth and development of medical technology help to improve the average life expectancy, but the western diet and rapid conversions to poor lifestyles lead an increasing risk of major chronic diseases. Coronary heart disease mortality in Korea has been on the increase, while showing a steady decline in the other industrialized countries. An age-period-cohort analysis can help understand the trends in mortality and predict the near future. We analyzed the time trends of ischemic heart disease mortality, which is on the increase, from 1985 to 2009 using an age-period-cohort model to characterize the effects of ischemic heart disease on changes in the mortality rate over time. All three effects on total ischemic heart disease mortality were statistically significant. Regarding the period effect, the mortality rate was decreased slightly in 2000 to 2004, after it had continuously increased since the late 1980s that trend was similar in both sexes. The expected age effect was noticeable, starting from the mid-60's. In addition, the age effect in women was more remarkable than that in men. Women born from the early 1900s to 1925 observed an increase in ischemic heart mortality. That cohort effect showed significance only in women. The future cohort effect might have a lasting impact on the risk of ischemic heart disease in women with the increasing elderly population, and a national prevention policy is need to establish management of high risk by considering the age-period-cohort effect.

Clinical evaluation of new automatic coronary-specific best cardiac phase selection algorithm for single-beat coronary CT angiography.

PubMed

Wang, Hui; Xu, Lei; Fan, Zhanming; Liang, Junfu; Yan, Zixu; Sun, Zhonghua

2017-01-01

The aim of this study was to evaluate the workflow efficiency of a new automatic coronary-specific reconstruction technique (Smart Phase, GE Healthcare-SP) for selection of the best cardiac phase with least coronary motion when compared with expert manual selection (MS) of best phase in patients with high heart rate. A total of 46 patients with heart rates above 75 bpm who underwent single beat coronary computed tomography angiography (CCTA) were enrolled in this study. CCTA of all subjects were performed on a 256-detector row CT scanner (Revolution CT, GE Healthcare, Waukesha, Wisconsin, US). With the SP technique, the acquired phase range was automatically searched in 2% phase intervals during the reconstruction process to determine the optimal phase for coronary assessment, while for routine expert MS, reconstructions were performed at 5% intervals and a best phase was manually determined. The reconstruction and review times were recorded to measure the workflow efficiency for each method. Two reviewers subjectively assessed image quality for each coronary artery in the MS and SP reconstruction volumes using a 4-point grading scale. The average HR of the enrolled patients was 91.1±19.0bpm. A total of 204 vessels were assessed. The subjective image quality using SP was comparable to that of the MS, 1.45±0.85 vs 1.43±0.81 respectively (p = 0.88). The average time was 246 seconds for the manual best phase selection, and 98 seconds for the SP selection, resulting in average time saving of 148 seconds (60%) with use of the SP algorithm. The coronary specific automatic cardiac best phase selection technique (Smart Phase) improves clinical workflow in high heart rate patients and provides image quality comparable with manual cardiac best phase selection. Reconstruction of single-beat CCTA exams with SP can benefit the users with less experienced in CCTA image interpretation.

Exercise Increases the Cardiovascular Stimulus Provided by Artificial Gravity

NASA Technical Reports Server (NTRS)

Howarth, M. S.; Moore, F. B.; Hinghofer-Szalkay, H.; Jezova, D.; Diedrich, A.; Ferris, M. B.; Schlegel, T. T.; Pathwardhan, A. R.; Knapp, C. F.; Evans, J. M.

2008-01-01

We investigated fluid shifts and regulatory responses to variations of posture, exercise, Gz level and radius of rotation in subjects riding NASA Ames 20G centrifuge. Results are from 4 protocols that address radius and exercise effects only. Protocol A: After 10 min supine control, 12 healthy men (35 plus or minus 9 yr, 82.8 plus or minus 7.9 kg) were exposed to rotational 1 Gz (2.5 m radius) for 2 min followed by 20 min alternating between 1 and 1.25 Gz. Blood samples were taken pre and post spin. Protocol B: Same as A, but lower limb exercise (70% V02max) preceded ramps to 1.25 Gz. Protocol C: Same as A but radius of rotation 8.3 m. Protocol D: Same as B but at 8.3 m. The 8 subjects who completed all protocols, increased heart rate (HR) from control, on average, by: A: 5, B: 39, C: 11, D: 44 bpm. For thoracic fluid volume, (bioimpedance), the 8 subjects changed from control, on average: A: -394, B: -548, C: -537, D: -708 mL. For thigh fluid volume, changes from control, on average, were: A: -137, B: 129, C: -75, D: 159 mL. Hematocrit changes from control were: A: 2.3, B: 3.5, C: 2.3, D: 4.3 %. Radius effects were mild and included greater loss of fluid from the thorax, less fluid loss from the thigh and increased heart rate at the longer radius. Pre-acceleration exercise effects were more dramatic and included additional loss of fluid from the chest, increased fluid volume of the thigh, increased hematocrit and greater heart rate increases. We propose that short bouts of intense exercise can be used to magnify the cardiovascular stress delivered by artificial gravity (AG) training and the combination of AG with exercise training can be fine-tuned to preserve orthostatic tolerance of astronauts during spaceflight.

Cardiovascular disease risk following a 758 km pilgrimage.

PubMed

Harris, M B; Wolf, M R

2013-08-01

Millions of people participate in pilgrimages around the world such as the Camino de Santiago. However, few studies have examined the effects of this type of activity on cardiovascular disease risk factors. The aim of this study is to evaluate changes in cardiovascular disease risk factors: c-reactive protein, cholesterol, triglycerides, blood pressure, and cardiorespiratory fitness levels following a 758 km, 30-day pilgrimage. 11 healthy male and female subjects between the ages of 18-56 participated in pre and post pilgrimage blood pressure and blood tests, as well as pre, during, and post pilgrimage weight, skin-fold, and aerobic fitness testing. Heart rate monitors and pedometers provided maximum, average, and minimum heart rates as well as distances covered during the exercise. The mean daily walking distance was 25 km at an average intensity of 55.96% (±1.93%) of maximum heart rate. Statistically significant changes were seen in body weight (79.3 kg±3.4 pre vs. 76.4±2.98 post, p<0.05), body fat percentage (24.48%±2.31% pre vs. 23.01%±2.12 post, p<0.05), systolic and diastolic blood pressure (119±3.82/75±2.73 pre vs. 110±5.07/69±3.10 post, p<0.05), as well as cardiorespiratory fitness. These data suggest that some cardiovascular disease risk factors can be improved in healthy subjects participating in a low intensity, long duration, high frequency activity such as a walking pilgrimage. © Georg Thieme Verlag KG Stuttgart · New York.

Independent, Community-Based Aerobic Exercise Training for People With Moderate-to-Severe Traumatic Brain Injury.

PubMed

Devine, Jennifer M; Wong, Bonnie; Gervino, Ernest; Pascual-Leone, Alvaro; Alexander, Michael P

2016-08-01

To determine whether people with moderate-to-severe traumatic brain injury (TBI) can adhere to a minimally supervised, community-based, vigorous aerobic exercise program. Prospective trial. Young Men's Christian Association (YMCA) facilities. Community-dwelling volunteers (N=10; 8 men, 2 women; age range, 22-49y) 6 to 15 months after moderate-to-severe TBI. Participants received memberships to local YMCAs and brief orientations to exercise. They were then asked to independently complete ≥12 weeks of ≥3 training sessions per week, performed at 65% to 85% of maximum heart rate for ≥30 minutes per session. Participants could self-select exercise modality, provided they met intensity and duration targets. Programmable heart rate monitors captured session intensity and duration. Independence with equipment and facility use and compliance with training goals (session frequency, duration, intensity, total weeks of training). All participants achieved independence with equipment and facility use. All met at least 2 of 4 training goals; half met all 4 goals. Participants averaged (±SD) 3.3±0.7 sessions per week for 13 weeks (range, 6-24). Average ± SD session duration was 62±23 minutes, of which 51±22 minutes occurred at or above individuals' heart rate training targets. People in recovery from moderate-to-severe TBI can, with minimal guidance, perform vigorous, community-based exercise. This suggests that decentralized exercise may be logistically and economically sustainable after TBI, expanding its potential therapeutic utility and rendering longer-duration exercise studies more feasible. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Regional myocardial oxygen tension: 19F MRI of sequestered perfluorocarbon.

PubMed

Shukla, H P; Mason, R P; Bansal, N; Antich, P P

1996-06-01

A novel noninvasive method of measuring local myocardial oxygen tension (pO2) in the perfused rat heart using 19F MRI is demonstrated. Tissue pO2 was determined on the basis of the 19F spin-lattice relaxation rate (R1) of perflubron (perfluorooctyl bromide) sequestered in the heart after IV infusion of an emulsion. Spectroscopic measurement of R1 was previously used to measure a global weighted average of oxygen status. 19F MRI now provides 3D spatial resolution indicating local cardiac pO2 under normally perfused, globally ischemic, and regionally ischemic conditions.

Cardiovascular changes in unanesthetized and ketamine-anesthetized Sprague-Dawley rats exposed to 2. 8-GHz radiofrequency radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jauchem, J.R.; Frei, M.R.

1991-01-01

Sprague-Dawley rats were exposed to 2.8-GHz radiofrequency radiation, first while unanesthetized and then while anesthetized with ketamine (150 mg/kg.I.M.). Irradiation at a power density of 60 mW/cm2 (whole-body average specific absorption rate of approximately 14 W/kg) was conducted for sufficient duration to increase colonic temperature from 38.5 to 39.5 degrees C. The time required for the temperature increase was significantly longer in the anesthetized state. During irradiation, heart rate increased significantly both with and without anesthesia, while mean arterial blood pressure increased only when the rats were unanesthetized. The heart rate increase in the anesthetized state contrasts with a lackmore » of change in a previous study of Fischer rats. This difference between anesthetized Sprague-Dawley and Fischer rats should be considered when comparing cardiovascular data obtained from these two strains of rats.« less

The effect of exercise training on biventricular myocardial strain in heart failure with preserved ejection fraction.

PubMed

Angadi, Siddhartha S; Jarrett, Catherine L; Sherif, Moustafa; Gaesser, Glenn A; Mookadam, Farouk

2017-08-01

High-intensity interval training (HIIT) improves peak oxygen uptake and left ventricular diastology in patients with heart failure with preserved ejection fraction (HFpEF). However, its effects on myocardial strain in HFpEF remain unknown. We explored the effects of HIIT and moderate-intensity aerobic continuous training (MI-ACT) on left and right ventricular strain parameters in patients with HFpEF. Furthermore, we explored their relationship with peak oxygen uptake (VO 2peak ). Fifteen patients with HFpEF (age = 70 ± 8.3 years) were randomized to either: (i) HIIT (4 × 4 min, 85-90% peak heart rate, interspersed with 3 min of active recovery; n = 9) or (ii) MI-ACT (30 min at 70% peak heart rate; n = 6). Patients were trained 3 days/week for 4 weeks and underwent VO 2peak testing and 2D echocardiography at baseline and after completion of the 12 sessions of supervised exercise training. Left ventricular (LV) and right ventricular (RV) average global peak systolic longitudinal strain (GLS) and peak systolic longitudinal strain rate (GSR) were quantified. Paired t-tests were used to examine within-group differences and unpaired t-tests used for between-group differences (α = 0.05). Right ventricular average global peak systolic longitudinal strain improved significantly in the HIIT group after training (pre = -18.4 ± 3.2%, post = -21.4 ± 1.7%; P = 0.02) while RV-GSR, LV-GLS, and LV-GSR did not (P > 0.2). No significant improvements were observed following MI-ACT. No significant between-group differences were observed for any strain measure. ΔLV-GLS and ΔRV-GLS were modestly correlated with ΔVO 2peak (r = -0.48 and r = -0.45; P = 0.1, respectively). In patients with HFpEF, 4 weeks of HIIT significantly improved RV-GLS. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Physical Activity During Recess Outdoors and Indoors Among Urban Public School Students, St. Louis, Missouri, 2010–2011

PubMed Central

Tran, Irene; Clark, B. Ruth

2013-01-01

We measured the quantity and intensity of physical activity in 106 urban public school students during recess outdoors, recess indoors in the gym, and recess indoors in the classroom. Students in grades 2 through 5 wore accelerometer pedometers for an average of 6.2 (standard deviation [SD], 1.4) recess periods over 8 weeks; a subsample of 26 also wore heart rate monitors. We determined, on the basis of 655 recess observations, that outdoor recess enabled more total steps per recess period (P < .0001), more steps in moderate-to-vigorous physical activity (P < .0001), and higher heart rates than recess in the gym or classroom. To maximize physical activity quantity and intensity, school policies should promote outdoor recess. PMID:24262028

Correlated and uncorrelated heart rate fluctuations during relaxing visualization

NASA Astrophysics Data System (ADS)

Papasimakis, N.; Pallikari, F.

2010-05-01

The heart rate variability (HRV) of healthy subjects practicing relaxing visualization is studied by use of three multiscale analysis techniques: the detrended fluctuation analysis (DFA), the entropy in natural time (ENT) and the average wavelet (AWC) coefficient. The scaling exponent of normal interbeat interval increments exhibits characteristics of the presence of long-range correlations. During relaxing visualization the HRV dynamics change in the sense that two new features emerge independent of each other: a respiration-induced periodicity that often dominates the HRV at short scales (<40 interbeat intervals) and the decrease of the scaling exponent at longer scales (40-512 interbeat intervals). In certain cases, the scaling exponent during relaxing visualization indicates the breakdown of long-range correlations. These characteristics have been previously seen in the HRV dynamics during non-REM sleep.

An adaptive Kalman filter approach for cardiorespiratory signal extraction and fusion of non-contacting sensors

PubMed Central

2014-01-01

Background Extracting cardiorespiratory signals from non-invasive and non-contacting sensor arrangements, i.e. magnetic induction sensors, is a challenging task. The respiratory and cardiac signals are mixed on top of a large and time-varying offset and are likely to be disturbed by measurement noise. Basic filtering techniques fail to extract relevant information for monitoring purposes. Methods We present a real-time filtering system based on an adaptive Kalman filter approach that separates signal offsets, respiratory and heart signals from three different sensor channels. It continuously estimates respiration and heart rates, which are fed back into the system model to enhance performance. Sensor and system noise covariance matrices are automatically adapted to the aimed application, thus improving the signal separation capabilities. We apply the filtering to two different subjects with different heart rates and sensor properties and compare the results to the non-adaptive version of the same Kalman filter. Also, the performance, depending on the initialization of the filters, is analyzed using three different configurations ranging from best to worst case. Results Extracted data are compared with reference heart rates derived from a standard pulse-photoplethysmographic sensor and respiration rates from a flowmeter. In the worst case for one of the subjects the adaptive filter obtains mean errors (standard deviations) of -0.2 min −1 (0.3 min −1) and -0.7 bpm (1.7 bpm) (compared to -0.2 min −1 (0.4 min −1) and 42.0 bpm (6.1 bpm) for the non-adaptive filter) for respiration and heart rate, respectively. In bad conditions the heart rate is only correctly measurable when the Kalman matrices are adapted to the target sensor signals. Also, the reduced mean error between the extracted offset and the raw sensor signal shows that adapting the Kalman filter continuously improves the ability to separate the desired signals from the raw sensor data. The average total computational time needed for the Kalman filters is under 25% of the total signal length rendering it possible to perform the filtering in real-time. Conclusions It is possible to measure in real-time heart and breathing rates using an adaptive Kalman filter approach. Adapting the Kalman filter matrices improves the estimation results and makes the filter universally deployable when measuring cardiorespiratory signals. PMID:24886253

An adaptive Kalman filter approach for cardiorespiratory signal extraction and fusion of non-contacting sensors.

PubMed

Foussier, Jerome; Teichmann, Daniel; Jia, Jing; Misgeld, Berno; Leonhardt, Steffen

2014-05-09

Extracting cardiorespiratory signals from non-invasive and non-contacting sensor arrangements, i.e. magnetic induction sensors, is a challenging task. The respiratory and cardiac signals are mixed on top of a large and time-varying offset and are likely to be disturbed by measurement noise. Basic filtering techniques fail to extract relevant information for monitoring purposes. We present a real-time filtering system based on an adaptive Kalman filter approach that separates signal offsets, respiratory and heart signals from three different sensor channels. It continuously estimates respiration and heart rates, which are fed back into the system model to enhance performance. Sensor and system noise covariance matrices are automatically adapted to the aimed application, thus improving the signal separation capabilities. We apply the filtering to two different subjects with different heart rates and sensor properties and compare the results to the non-adaptive version of the same Kalman filter. Also, the performance, depending on the initialization of the filters, is analyzed using three different configurations ranging from best to worst case. Extracted data are compared with reference heart rates derived from a standard pulse-photoplethysmographic sensor and respiration rates from a flowmeter. In the worst case for one of the subjects the adaptive filter obtains mean errors (standard deviations) of -0.2 min(-1) (0.3 min(-1)) and -0.7 bpm (1.7 bpm) (compared to -0.2 min(-1) (0.4 min(-1)) and 42.0 bpm (6.1 bpm) for the non-adaptive filter) for respiration and heart rate, respectively. In bad conditions the heart rate is only correctly measurable when the Kalman matrices are adapted to the target sensor signals. Also, the reduced mean error between the extracted offset and the raw sensor signal shows that adapting the Kalman filter continuously improves the ability to separate the desired signals from the raw sensor data. The average total computational time needed for the Kalman filters is under 25% of the total signal length rendering it possible to perform the filtering in real-time. It is possible to measure in real-time heart and breathing rates using an adaptive Kalman filter approach. Adapting the Kalman filter matrices improves the estimation results and makes the filter universally deployable when measuring cardiorespiratory signals.

Pilot study of an Internet patient-physician communication tool for heart failure disease management.

PubMed

Wu, Robert C; Delgado, Diego; Costigan, Jeannine; Ross, Heather; MacIver, Jane

2006-01-01

Internet disease management has the promise of improving care in patients with heart failure but evidence supporting its use is limited. We have designed a Heart Failure Internet Communication Tool (HFICT), allowing patients to enter messages for clinicians, as well as their daily symptoms, weight, blood pressure and heart rate. Clinicians review the information on the same day and provide feedback. This pilot study evaluated the feasibility and patients' acceptability of using the Internet to communicate with patients with symptomatic heart failure. Patients with symptomatic heart failure were instructed how to use the Internet communication tool. The primary outcome measure was the proportion of patients who used the system regularly by entering information on average at least once per week for at least 3 months. Secondary outcomes measures included safety and maintainability of the tool. We also conducted a content analysis of a subset of the patient and clinician messages entered into the comments field. Between 3 May 1999 and 1 November 2002, 62 patients (mean age 48.7 years) were enrolled. At 3 months 58 patients were alive and without a heart transplant. Of those, 26 patients (45%; 95% Confidence Interval, 0.33-0.58) continued using the system at 3 months. In 97% of all entries by participants weight was included; 68% of entries included blood pressure; and 71% of entries included heart rate. In 3,386 entries out of all 5,098 patient entries (66%), comments were entered. Functions that were not used included the tracking of diuretics, medications and treatment goals. The tool appeared to be safe and maintainable. Workload estimates for clinicians for entering a response to each patient's entry ranged from less than a minute to 5 minutes or longer for a detailed response. Patients sent 3,386 comments to the Heart Function Clinic. Based on the content analysis of 100 patient entries, the following major categories of communication were identified: patient information; patient symptoms; patient questions regarding their condition; patient coordinating own care; social responses. The number of comments decreased over time for both patients and clinicians. While the majority of patients discontinued use, 45% of the patients used the system and continued to use it on average for 1.5 years. An Internet tool is a feasible method of communication in a substantial proportion of patients with heart failure. Further study is required to determine whether clinical outcomes, such as quality of life or frequency of hospitalization, are improved.

The Association between Noise, Cortisol and Heart Rate in a Small-Scale Gold Mining Community—A Pilot Study

PubMed Central

Green, Allyson; Jones, Andrew D.; Sun, Kan; Neitzel, Richard L.

2015-01-01

We performed a cross-sectional pilot study on salivary cortisol, heart rate, and personal noise exposures in a small-scale gold mining village in northeastern Ghana in 2013. Cortisol level changes between morning and evening among participants showed a relatively low decline in cortisol through the day (−1.44 ± 4.27 nmol/L, n = 18), a pattern consistent with chronic stress. A multiple linear regression, adjusting for age, sex, smoking status, and time between samples indicated a significant increase of 0.25 nmol/L cortisol from afternoon to evening per 1 dBA increase in equivalent continuous noise exposure (Leq) over that period (95% CI: 0.08–0.42, Adj R2 = 0.502, n = 17). A mixed effect linear regression model adjusting for age and sex indicated a significant increase of 0.29 heart beats per minute (BPM) for every 1 dB increase in Leq. Using standard deviations (SDs) as measures of variation, and adjusting for age and sex over the sampling period, we found that a 1 dBA increase in noise variation over time (Leq SD) was associated with a 0.5 BPM increase in heart rate SD (95% CI: 0.04–−0.9, Adj. R2 = 0.229, n = 16). Noise levels were consistently high, with 24-hour average Leq exposures ranging from 56.9 to 92.0 dBA, with a mean daily Leq of 82.2 ± 7.3 dBA (mean monitoring duration 22.1 ± 1.9 hours, n = 22). Ninety-five percent of participants had 24-hour average Leq noise levels over the 70 dBA World health Organization (WHO) guideline level for prevention of hearing loss. These findings suggest that small-scale mining communities may face multiple, potentially additive health risks that are not yet well documented, including hearing loss and cardiovascular effects of stress and noise. PMID:26308019

The Association between Noise, Cortisol and Heart Rate in a Small-Scale Gold Mining Community-A Pilot Study.

PubMed

Green, Allyson; Jones, Andrew D; Sun, Kan; Neitzel, Richard L

2015-08-21

We performed a cross-sectional pilot study on salivary cortisol, heart rate, and personal noise exposures in a small-scale gold mining village in northeastern Ghana in 2013. Cortisol level changes between morning and evening among participants showed a relatively low decline in cortisol through the day (-1.44 ± 4.27 nmol/L, n = 18), a pattern consistent with chronic stress. A multiple linear regression, adjusting for age, sex, smoking status, and time between samples indicated a significant increase of 0.25 nmol/L cortisol from afternoon to evening per 1 dBA increase in equivalent continuous noise exposure (Leq) over that period (95% CI: 0.08-0.42, Adj R(2) = 0.502, n = 17). A mixed effect linear regression model adjusting for age and sex indicated a significant increase of 0.29 heart beats per minute (BPM) for every 1 dB increase in Leq. Using standard deviations (SDs) as measures of variation, and adjusting for age and sex over the sampling period, we found that a 1 dBA increase in noise variation over time (Leq SD) was associated with a 0.5 BPM increase in heart rate SD (95% CI: 0.04--0.9, Adj. R(2) = 0.229, n = 16). Noise levels were consistently high, with 24-hour average Leq exposures ranging from 56.9 to 92.0 dBA, with a mean daily Leq of 82.2 ± 7.3 dBA (mean monitoring duration 22.1 ± 1.9 hours, n = 22). Ninety-five percent of participants had 24-hour average Leq noise levels over the 70 dBA World health Organization (WHO) guideline level for prevention of hearing loss. These findings suggest that small-scale mining communities may face multiple, potentially additive health risks that are not yet well documented, including hearing loss and cardiovascular effects of stress and noise.

A novel handheld device for use in remote patient monitoring of heart failure patients--design and preliminary validation on healthy subjects.

PubMed

Pollonini, Luca; Rajan, Nithin O; Xu, Shuai; Madala, Sridhar; Dacso, Clifford C

2012-04-01

Remote patient monitoring (RPM) holds great promise for reducing the burden of congestive heart failure (CHF). Improved sensor technology and effective predictive algorithms can anticipate sudden decompensation events. Enhanced telemonitoring systems would promote patient independence and facilitate communication between patients and their physicians. We report the development of a novel hand-held device, called Blue Box, capable of collecting and wirelessly transmitting key cardiac parameters derived from three integrated biosensors: 2 lead electrocardiogram (ECG), photoplethysmography and bioelectrical impedance (bioimpedance). Blue Box measurements include time intervals between consecutive ECG R-waves (RR interval), time duration of the ECG complex formed by the Q, R and S waves (QRS duration), bioimpedance, heart rate and systolic time intervals. In this study, we recruited 24 healthy subjects to collect several parameters measured by Blue Box and assess their value in correlating with cardiac output measured with Echo-Doppler. Linear correlation between the heart rate measured with Blue Box and cardiac output from Echo-Doppler had a group average correlation coefficient of 0.80. We found that systolic time intervals did not improve the model significantly. However, STIs did inversely correlate with increasing workloads.

The daily rhythm of body temperature, heart and respiratory rate in newborn dogs.

PubMed

Piccione, Giuseppe; Giudice, Elisabetta; Fazio, Francesco; Mortola, Jacopo P

2010-08-01

We asked whether, during the postnatal period, the daily patterns of body temperature (Tb), heart rate (HR) and breathing frequency (f) begin and develop in synchrony. To this end, measurements of HR, f and Tb were performed weekly, on two consecutive days, for the first two postnatal months on puppies of three breeds of dogs (Rottweiler, Cocker Spaniel and Carlino dogs) with very different birth weights and postnatal growth patterns. Ambient conditions and feeding habits were constant for all puppies. The results indicated that (1) the 24-h average Tb increased and average HR and f decreased with growth, (2) the daily rhythms in Tb were apparent by 4 weeks, irrespective of the puppy's growth pattern, (3) the daily rhythm of Tb in the puppy was not necessarily following that of the mother; in fact, it could anticipate it. (4) The daily rhythms in HR and f were not apparent for the whole study period. We conclude that in neonatal dogs the onset of the daily rhythms of Tb has no obvious relationship with body size or rate of growth and is not cued by the maternal Tb rhythm. The daily rhythms of HR and f do not appear before 2 months of age. Hence, they are not in synchrony with those of Tb.

Automated Detection of Atrial Fibrillation Based on Time-Frequency Analysis of Seismocardiograms.

PubMed

Hurnanen, Tero; Lehtonen, Eero; Tadi, Mojtaba Jafari; Kuusela, Tom; Kiviniemi, Tuomas; Saraste, Antti; Vasankari, Tuija; Airaksinen, Juhani; Koivisto, Tero; Pankaala, Mikko

2017-09-01

In this paper, a novel method to detect atrial fibrillation (AFib) from a seismocardiogram (SCG) is presented. The proposed method is based on linear classification of the spectral entropy and a heart rate variability index computed from the SCG. The performance of the developed algorithm is demonstrated on data gathered from 13 patients in clinical setting. After motion artifact removal, in total 119 min of AFib data and 126 min of sinus rhythm data were considered for automated AFib detection. No other arrhythmias were considered in this study. The proposed algorithm requires no direct heartbeat peak detection from the SCG data, which makes it tolerant against interpersonal variations in the SCG morphology, and noise. Furthermore, the proposed method relies solely on the SCG and needs no complementary electrocardiography to be functional. For the considered data, the detection method performs well even on relatively low quality SCG signals. Using a majority voting scheme that takes five randomly selected segments from a signal and classifies these segments using the proposed algorithm, we obtained an average true positive rate of [Formula: see text] and an average true negative rate of [Formula: see text] for detecting AFib in leave-one-out cross-validation. This paper facilitates adoption of microelectromechanical sensor based heart monitoring devices for arrhythmia detection.

Influence of music on maximal self-paced running performance and passive post-exercise recovery rate.

PubMed

Lee, Sam; Kimmerly, Derek S

2016-01-01

The purpose of this study was to examine the influence of fast tempo music (FM) on self-paced running performance (heart rate, running speed, ratings of perceived exertion), and slow tempo music (SM) on post-exercise heart rate and blood lactate recovery rates. Twelve participants (5 women) completed three randomly assigned conditions: static noise (control), FM and SM. Each condition consisted of self-paced treadmill running, and supine postexercise recovery periods (20 min each). Average running speed, heart rate (HR) and ratings of perceived exertion (RPE) were measured during the treadmill running period, while HR and blood lactate were measured during the recovery period. Listening to FM during exercise resulted in a faster self-selected running speed (10.8±1.7 vs. 9.9±1.4 km•hour-1, P<0.001) and higher peak HR (184±12 vs. 177±17 beats•min-1, P<0.01) without a corresponding difference in peak RPE (FM, 16.8±1.8 vs. SM 15.7±1.9, P=0.10). Listening to SM during the post-exercise period resulted in faster HR recovery throughout (main effect P<0.001) and blood lactate at the end of recovery (2.8±0.4 vs. 4.7±0.8 mmol•L-1, P<0.05). Listening to FM during exercise can increase self-paced intensity without altering perceived exertion levels while listening to SM after exercise can accelerate the recovery rate back to resting levels.

Influence of music on maximal self-paced running performance and passive post-exercise recovery rate.

PubMed

Lee, S; Kimmerly, D

2014-10-30

The purpose of this study was to examine the influence of fast tempo music (FM) on self--paced running performance (heart rate, running speed, ratings of perceived exertion), and slow tempo music (SM) on post--exercise heart rate and blood lactate recovery rates. Twelve participants (5 Women) completed three randomly assigned conditions: static noise (control), FM and SM. Each condition consisted of self--paced treadmill running, and supine post--exercise recovery periods (20 min each). Average running speed, heart rate (HR) and ratings of perceived exertion (RPE) were measured during the treadmill running period, while HR and blood lactate were measured during the recovery period. Listening to FM during exercise resulted in a faster self--selected running speed (10.8 ± 1.7 vs. 9.9 ± 1.4 km•hour--1, p<0.001) and higher peak HR (184 ± 12 vs. 177 ± 17 beats•min--1, p< 0.01) without a corresponding difference in peak RPE (FM, 16.8 ± 1.8 vs. SM 15.7 ± 1.9, p= 0.10). Listening to SM during the post--exercise period reduced HR throughout (main effect p<0.001) and blood lactate at the end of recovery (2.8 ± 0.4 vs. 4.7 ± 0.8 mmol•L--1, p<0.05). Listening to FM during exercise can increase self--paced intensity without altering perceived exertion levels while listening to SM after exercise can accelerate the recovery rate back to resting levels.

Electroacupuncture most effectively elicits depressor and bradycardic responses at 1 Hz in humans.

PubMed

Nakahara, Hidehiro; Kawada, Toru; Ueda, Shin-ya; Kawai, Eriko; Yamamoto, Hiromi; Sugimachi, Masaru; Miyamoto, Tadayoshi

2016-02-01

Acupuncture stimulation is known to act on the autonomic nervous system and elicits depressor and bradycardic effects. However, previous studies on humans did not conduct quantitative analyses on optimal acupuncture conditions such as the stimulation frequency and duration to achieve maximum depressor and bradycardic effects. The aim of the present study was to investigate the effects of varying stimulation frequencies of electroacupuncture on time-dependent changes in blood pressure and heart rate in humans. Twelve healthy volunteers participated in the study. An acupuncture needle was inserted at the Ximen acupoint (PC4 according to WHO nomenclature), located at the anterior aspect of the forearm. An electrical stimulation was delivered through the acupuncture needle at an intensity of 1 V, pulse width of 5 ms, and stimulation frequencies of 0.5, 1, 5, and 10 Hz in a random order. The duration of electroacupuncture was 6 min, during which blood pressure and heart rate responses were monitored. Group-averaged data indicated that 1-Hz electroacupuncture decreased blood pressure and heart rate. Blood pressure was significantly decreased from the prestimulation baseline value of 86.6 ± 2.9 to 81.4 ± 2.3 mmHg during 4-6 min of 1-Hz electroacupuncture (mean ± SE, P < 0.01). Heart rate was also significantly decreased (from 66.2 ± 2.0 to 62.7 ± 1.7 beats/min, P < 0.01). These results provide fundamental evidence that bradycardiac and depressor responses are effectively produced by electrical acupuncture in humans.

Changes in the heart rate recovery to endurance effort after high intensity interval, strength, and concurrent exercise training in patients with insulin resistance.

PubMed

Álvarez, Cristian; Ramírez-Campillo, Rodrigo; Martínez, Cristian; Castro-Sepúlveda, Mauricio; Cano-Montoya, Johnathan; Mancilla, Rodrigo; Flores-Opazo, Marcelo

2017-11-01

The aim of this study was to assess the effects of three exercise training programs in the adaptation of the heart rate recovery of patients with insulin resistance. We studied 43 women with insulin resistance, which were assigned to three training groups: 1) high intensity interval training (HIT, age 39.0±10 years); 2) strength training (ST, age 33.9±9.4 years); 3) HIT+ST (MIXT, age 43.3±8.1 years); and 4) control group (CG, age 40.1±11 years). Heart rate was measured at rest (HRrest), during the 2-km-walking-test (UKKT) for mean (HRDE), and maximum (HRMDE) values, and during the recovery at one, two, and three minutes after the UKKT. Additionally, anthropometric measurements (body mass and body mass index) were assessed. HIT significantly decreased HRrest and HRDE (-4.5% and -2% respectively, P<0.05). MIXT training also decreased HRDE in -3% whilst both average and maximal HR during UKK were significantly increased in the control group HRDE (+2% and +3% respectively). Moreover, there were significant reductions in HR recovery at 1, 2 and 3 minutes after both HIT and MIXT training, whereas these values were increased in control group. Our findings suggest that HIT induces meaningful cardiovascular adaptations in patient with insulin resistance, reducing heart rate at rest, as well as during and after exercise, and that complementary strength training increases these adaptations.

Cardiovascular and respiratory physiopathological aspects of hypokinesia

NASA Technical Reports Server (NTRS)

Dagianti, A.

1980-01-01

The many effects of hypokinesia on the human organism are described. The differences in normally mobile subjects and hypokinetic subjects as relates to heart rate, average humeral pressure, cardiac capacity, cardia index, systolic range, and large cycle resistances are discussed. It is concluded that further studies must be carried out in seven specific areas of cariocirculatory damage due to hypokinesia.

The relation between tilt table and acceleration-tolerance and their dependence on stature and physical fitness

NASA Technical Reports Server (NTRS)

Klein, K. E.; Backhausen, F.; Bruner, H.; Eichhorn, J.; Jovy, D.; Schotte, J.; Vogt, L.; Wegman, H. M.

1980-01-01

A group of 12 highly trained athletes and a group of 12untrained students were subjected to passive changes of position on a tilt table and positive accelerations in a centrifuge. During a 20 min tilt, including two additional respiratory maneuvers, the number of faints and average cardiovascular responses did not differ significantly between the groups. During linear increase of acceleration, the average blackout level was almost identical in both groups. Statistically significant coefficients of product-moment correlation for various relations were obtained. The coefficient of multiple determination computed for the dependence of acceleration tolerance on heart-eye distance and systolic blood pressure at rest allows the explanation of almost 50% of the variation of acceleration tolerance. The maximum oxygen uptake showed the expected significant correlation to the heart rate at rest, but not the acceleration tolerance, or to the cardiovascular responses to tilting.

The effects of caffeine in women during aerobic-dance bench stepping.

PubMed

Ahrens, Jennifer N; Lloyd, Lisa K; Crixell, Sylvia H; Walker, John L

2007-02-01

People of all ages and fitness levels participate regularly in aerobic-dance bench stepping (ADBS) to increase fitness and control body weight. Any reasonable method for enhancing the experience or effectiveness of ADBS would be beneficial. This study examined the acute effects of a single dose of caffeine on physiological responses during ADBS in women. When compared with a placebo, neither a 3- nor a 6-mg/kg dose of caffeine altered physiological responses or rating of perceived exertion (RPE) in 20 women (age 19-28 y) of average fitness level, not habituated to caffeine, while they performed an ADBS routine. Since neither dose of caffeine had any effect on VO2, VCO2, minute ventilation, respiratory-exchange ratio, rate of energy expenditure, heart rate, or RPE during ADBS exercise, it would not be prudent for a group exercise leader to recommend caffeine to increase energy cost or decrease perception of effort in an ADBS session. Furthermore, caffeine ingestion should not interfere with monitoring intensity using heart rate or RPE during ADBS.

Serum high density lipoprotein cholesterol, alcohol, and coronary mortality in male smokers.

PubMed Central

Paunio, M.; Virtamo, J.; Gref, C. G.; Heinonen, O. P.

1996-01-01

OBJECTIVE--To determine whether the increase in mortality from coronary heart disease with high concentration (> 1.75 mmol/l) of high density lipoprotein cholesterol could be due to alcohol intake. DESIGN--Cohort study. SETTING--Placebo group of the alpha tocopherol, beta carotene cancer prevention (ATBC) study of south western population in Finland. PARTICIPANTS--7052 male smokers aged 50-69 years enrolled to the ATBC study in the 1980s. MAIN OUTCOME MEASURES--The relative and absolute rates adjusted for risk factors for clinically or pathologically verified deaths from coronary heart disease for different concentrations of high density lipoprotein cholesterol with and without stratification for alcohol intake. Similar rates were also calculated for different alcohol consumption groups. RESULTS--During the average follow up period of 6.7 years 258 men died from verified coronary heart disease. Coronary death rate steadily decreased with increasing concentration of high density lipoprotein cholesterol until a high concentration. An increase in the rate was observed above 1.75 mmol/l. This increase occurred among those who reported alcohol intake. Mortality was associated with alcohol intake in a J shaped dose response, and those who reported consuming more than five drinks a day (heavy drinkers) had the highest death rate. Mortality was higher in heavy drinkers than in non-drinkers or light or moderate drinkers in all high density lipoprotein categories from 0.91 mmol/l upward. CONCLUSIONS--Mortality from coronary heart disease increases at concentrations of high density lipoprotein cholesterol over 1.75 mmol/l. The mortality was highest among heavy drinkers, but an increase was found among light drinkers also. PMID:8634563

Heart rate profile during exercise in patients with early repolarization.

PubMed

Cay, Serkan; Cagirci, Goksel; Atak, Ramazan; Balbay, Yucel; Demir, Ahmet Duran; Aydogdu, Sinan

2010-09-01

Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise. A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed. Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrement of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group (all P < 0.05). The lower heart rate increment (< 106 beats/min) and heart rate decrement (< 95 beats/min) were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 (95%CI 1.21-7.34) (P = 0.018) and 7.73 (95%CI 2.84-21.03) (P < 0.001) for the lower heart rate increment and heart rate decrement compared to higher levels, respectively. Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.

High-intensity interval running is perceived to be more enjoyable than moderate-intensity continuous exercise: implications for exercise adherence.

PubMed

Bartlett, Jonathan D; Close, Graeme L; MacLaren, Don P M; Gregson, Warren; Drust, Barry; Morton, James P

2011-03-01

The aim of this study was to objectively quantify ratings of perceived enjoyment using the Physical Activity Enjoyment Scale following high-intensity interval running versus moderate-intensity continuous running. Eight recreationally active men performed two running protocols consisting of high-intensity interval running (6 × 3 min at 90% VO(2max) interspersed with 6 × 3 min active recovery at 50% VO(2max) with a 7-min warm-up and cool down at 70% VO(2max)) or 50 min moderate-intensity continuous running at 70% VO(2max). Ratings of perceived enjoyment after exercise were higher (P < 0.05) following interval running compared with continuous running (88 ± 6 vs. 61 ± 12) despite higher (P < 0.05) ratings of perceived exertion (14 ± 1 vs. 13 ± 1). There was no difference (P < 0.05) in average heart rate (88 ± 3 vs. 87 ± 3% maximum heart rate), average VO(2) (71 ± 6 vs. 73 ± 4%VO(2max)), total VO(2) (162 ± 16 vs. 166 ± 27 L) or energy expenditure (811 ± 83 vs. 832 ± 136 kcal) between protocols. The greater enjoyment associated with high-intensity interval running may be relevant for improving exercise adherence, since running is a low-cost exercise intervention requiring no exercise equipment and similar relative exercise intensities have previously induced health benefits in patient populations.

Association of the consumption of common food groups and beverages with mortality from cancer, ischaemic heart disease and diabetes mellitus in Serbia, 1991–2010: an ecological study

PubMed Central

Ilic, Milena; Ilic, Irena; Stojanovic, Goran; Zivanovic-Macuzic, Ivana

2016-01-01

Objectives This paper reports association between mortality rates from cancer, ischaemic heart disease and diabetes mellitus and the consumption of common food groups and beverages in Serbia. Design In this ecological study, data on both mortality and the average annual consumption of common food groups and beverages per household's member were obtained from official data-collection sources. The multivariate linear regression analysis was used to determine the strength of the associations between consumption of common food groups and beverages and mortality rates. Results Markedly increasing trends of cancer, ischaemic heart disease and diabetes mellitus mortality rates were observed in Serbia in the period 1991–2010. Mortality rates from cancer were negatively associated with consumption of vegetable oil (p=0.005) and grains (p=0.001), and same was found for ischaemic heart disease (p=0.002 and 0.021, respectively), while consumption of other dairy products showed a significant positive association (p<0.001 and p=0.032, respectively). In men and women, mortality rates from diabetes mellitus showed a significant positive association with consumption of poultry (p=0.014 and 0.004, respectively). Consumption of beef and grains showed a significant negative association with cancer mortality rates in both genders (p=0.002 and p<0.001 in men, and p<0.001 and p=0.014 in women, respectively), while consumption of cheese was negatively associated only in men (p<0.001). Mortality from diabetes mellitus showed a significant positive association with consumption of animal fat and other dairy products only in women (p=0.003 and 0.046, respectively). Conclusions Association between unfavourable mortality trends from cancer, ischaemic heart disease and diabetes mellitus, and common food groups and beverages consumption was observed and should be assessed in future analytical epidemiological studies. Promotion of healthy diet is sorely needed in Serbia. PMID:26733565

Influence of Dai-kenchu-to (DKT) on human portal blood flow.

PubMed

Ogasawara, Takashi; Morine, Yuji; Ikemoto, Tetsuya; Imura, Satoru; Fujii, Masahiko; Soejima, Yuji; Shimada, Mitsuo

2008-01-01

Dai-kenchu-to (DKT) is known as an herbal medicine used for postoperative ileus. However, no report exists about the effect of DKT on portal blood flow. The aim of this study is to clarify the influence of DKT on portal blood flow. To healthy volunteers (Healthy; n = 6), cirrhotic patients (Cirrhosis; n = 7) and liver-transplant patients (LTx; n = 3), DKT (2.5g) with 100mL of warm water was orally administrated in the DKT group, and only warm water was administrated in the control group. The portal blood flow rate (M-VEL: cm/sec.) and portal blood flow (Flow volume: mL/min.) was measured each time after administration using an ultrasonic Doppler method. Furthermore, the arterial blood pressure and heart rate was measured at the same time points. In the DKT group, a significant increase of M-VEL (120%) and flow volume (150%) 30 minutes after administration was observed in both Healthy and Cirrhosis in comparison with the control group. In LTx, there was also a significant increase of flow volume (128%) 30 minutes after administration. However, there was no change in average blood pressure and heart rate in all groups. DKT increases portal blood flow in early phase after oral administration without any significant changes in the blood pressure and heart rate.

Association of heart rate profile during exercise with the severity of coronary artery disease.

PubMed

Cay, Serkan; Ozturk, Sezgin; Biyikoglu, Funda; Yildiz, Abdulkadir; Cimen, Tolga; Uygur, Belma; Tuna, Funda

2009-05-01

Coronary artery disease is the leading cause of morbidity and mortality around the world. Autonomic nervous system abnormalities are associated with coronary artery disease and its complications. Exercise stress tests are routinely used for the detection of the presence of coronary artery disease. In this study, we observed the association between heart rate profile during exercise and the severity of coronary artery disease. One hundred and sixty patients with abnormal exercise treadmill test (> or =1 mm horizontal or downsloping ST-segment depression; 119 men, 41 women; mean age = 57 +/- 9 years) were included in the study. Use of any drug affecting heart rate was not permitted. Resting heart rate before exercise, maximum heart rate during exercise, and resting heart rate after exercise (5 min later) were measured and two parameters were calculated: heart rate increment (maximum heart rate - resting heart rate before exercise) and heart rate decrement (maximum heart rate - resting heart rate after exercise). All patients underwent selective coronary angiography and subclassified into two groups according to stenotic lesion severity. Group 1 had at least 50% of stenotic lesion and group 2 had less than 50%. Patients in the first group had increased resting heart rate, decreased maximum heart rate, decreased heart rate increment, and decreased heart rate decrement compared with second group. All patients were classified into tertiles of resting heart rate, heart rate increment, and heart rate decrement level to evaluate whether these parameters were associated with severity of coronary artery stenosis in the study. The multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 21.888 (95% confidence interval 6.983-68.606) for the highest tertile of resting heart rate level compared with the lowest tertile. In addition, the multiple-adjusted odds ratio of the risk of severe coronary atherosclerosis was 20.987 (95% confidence interval 6.635-66.387) for the lowest tertile of heart rate increment level compared with the highest tertile and 2.360 (95% confidence interval 1.004-5.544) for the lowest tertile of heart rate decrement level compared with the highest tertile. Altered autonomic nervous system regulation affects heart rate profile, increased resting heart rate, decreased heart rate increment, and decreased heart rate decrement, during exercise and this effect is strongly and independently associated with the severity of coronary artery disease.

The effect of live music on decreasing anxiety in patients undergoing chemotherapy treatment.

PubMed

Ferrer, Alejandra J

2007-01-01

The purpose of this study was to investigate the effects of familiar live music on the anxiety levels of patients undergoing chemotherapy treatment. Randomly selected patients were assigned to experimental (n = 25) and control (n = 25) conditions. Pre and posttests consisted of questionnaires and the recording of the patient's heart rate and blood pressures. Subjects in the experimental group received 20 minutes of familiar live music during their chemotherapy treatment. Subjects in the control group received standard chemotherapy. It was assumed that those patients receiving music intervention would: (a) lower their anxiety levels; (b) experience a decrease in heart rate and blood pressure; (c) improve their levels of negative reactions including fatigue, worry, and fear; and (d) improve their levels of positive reactions including comfort and relaxation. Results of the study showed statistically significant improvement for the experimental group on the measures of anxiety, fear, fatigue, relaxation, and diastolic blood pressure. No significant differences between groups were found for heart rate and systolic blood pressure. Descriptive values indicated that, on average, the experimental group was influenced positively by the music intervention, and participants improved their quality of life while undergoing chemotherapy treatment.

Pre-performance Physiological State: Heart Rate Variability as a Predictor of Shooting Performance.

PubMed

Ortega, E; Wang, C J K

2018-03-01

Heart rate variability (HRV) is commonly used in sport science for monitoring the physiology of athletes but not as an indicator of physiological state from a psychological perspective. Since HRV is established to be an indicator of emotional responding, it could be an objective means of quantifying an athlete's subjective physiological state before competition. A total of 61 sport shooters participated in this study, of which 21 were novice shooters, 19 were intermediate shooters, and 21 were advanced level shooters. HRV, self-efficacy, and use of mental skills were assessed before they completed a standard shooting performance task of 40 shots, as in a competition qualifying round. The results showed that HRV was significantly positively correlated with self-efficacy and performance and was a significant predictor of shooting performance. In addition, advanced shooters were found to have significantly lower average heart rate before shooting and used more self-talk, relaxation, imagery, and automaticity compared to novice and intermediate shooters. HRV was found to be useful in identifying the physiological state of an athlete before competing, and as such, coaches and athletes can adopt practical strategies to improve the pre-performance physiological state as a means to optimize performance.

Heart Rate Variability Moderates the Association Between Separation-Related Psychological Distress and Blood Pressure Reactivity Over Time.

PubMed

Bourassa, Kyle J; Hasselmo, Karen; Sbarra, David A

2016-08-01

Divorce is a stressor associated with long-term health risk, though the mechanisms of this effect are poorly understood. Cardiovascular reactivity is one biological pathway implicated as a predictor of poor long-term health after divorce. A sample of recently separated and divorced adults (N = 138) was assessed over an average of 7.5 months to explore whether individual differences in heart rate variability-assessed by respiratory sinus arrhythmia-operate in combination with subjective reports of separation-related distress to predict prospective changes in cardiovascular reactivity, as indexed by blood pressure reactivity. Participants with low resting respiratory sinus arrhythmia at baseline showed no association between divorce-related distress and later blood pressure reactivity, whereas participants with high respiratory sinus arrhythmia showed a positive association. In addition, within-person variation in respiratory sinus arrhythmia and between-persons variation in separation-related distress interacted to predict blood pressure reactivity at each laboratory visit. Individual differences in heart rate variability and subjective distress operate together to predict cardiovascular reactivity and may explain some of the long-term health risk associated with divorce. © The Author(s) 2016.

The relationship between areca nut usage and heart rate in lactating Bangladeshis.

PubMed

Vinoy, S; Mascie-Taylor, C G N; Rosetta, L

2002-01-01

The betel-nut quid, a piece of areca nut chewed alone or mixed with tobacco and slaked lime wrapped in betel vine leaf, is widely used in Asian populations as a stimulant (due to the cholinergic agent, arecoline) or as a relaxant (due to arecaidine and guvacine). This study, which formed part of a larger project assessing the effect of energy expenditure on the duration of post-partum amenorrhoea, provided the opportunity to assess the role of chronic areca nut usage on heart rate and oxygen consumption during resting periods and during graded stepping tests. The mothers (n = 47), all of whom were lactating, were aged between 19 and 39, of low nutritional status and anaemic and they all chewed betel quid daily. Moderate users of betel quid (defined as more than 3 times a day) were found, on average, to have a significantly lower heart rate at rest and during exercise than low betel quid users (less than 3 times a day) but there was no modification in oxygen consumption. Chronic betel quid use does not seem to affect the assessment of 24h energy expenditure provided that subjects are denied access to betel nut usage before and during calibration.

High-resolution motion-compensated imaging photoplethysmography for remote heart rate monitoring

NASA Astrophysics Data System (ADS)

Chung, Audrey; Wang, Xiao Yu; Amelard, Robert; Scharfenberger, Christian; Leong, Joanne; Kulinski, Jan; Wong, Alexander; Clausi, David A.

2015-03-01

We present a novel non-contact photoplethysmographic (PPG) imaging system based on high-resolution video recordings of ambient reflectance of human bodies that compensates for body motion and takes advantage of skin erythema fluctuations to improve measurement reliability for the purpose of remote heart rate monitoring. A single measurement location for recording the ambient reflectance is automatically identified on an individual, and the motion for the location is determined over time via measurement location tracking. Based on the determined motion information motion-compensated reflectance measurements at different wavelengths for the measurement location can be acquired, thus providing more reliable measurements for the same location on the human over time. The reflectance measurement is used to determine skin erythema fluctuations over time, resulting in the capture of a PPG signal with a high signal-to-noise ratio. To test the efficacy of the proposed system, a set of experiments involving human motion in a front-facing position were performed under natural ambient light. The experimental results demonstrated that skin erythema fluctuations can achieve noticeably improved average accuracy in heart rate measurement when compared to previously proposed non-contact PPG imaging systems.

Elevated biomarkers of sympatho-adrenomedullary activity linked to e-waste air pollutant exposure in preschool children.

PubMed

Cong, Xiaowei; Xu, Xijin; Xu, Long; Li, Minghui; Xu, Cheng; Qin, Qilin; Huo, Xia

2018-06-01

Air pollution is a risk factor for cardiovascular disease (CVD), and cardiovascular regulatory changes in childhood contribute to the development and progression of cardiovascular events at older ages. The aim of the study was to investigate the effect of air pollutant exposure on the child sympatho-adrenomedullary (SAM) system, which plays a vital role in regulating and controlling the cardiovascular system. Two plasma biomarkers (plasma epinephrine and norepinephrine) of SAM activity and heart rate were measured in preschool children (n = 228) living in Guiyu, and native (n = 104) and non-native children (n = 91) living in a reference area (Haojiang) for >1 year. Air pollution data, over the 4-months before the health examination, was also collected. Environmental PM 2.5 , PM 10 , SO 2 , NO 2 and CO, plasma norepinephrine and heart rate of the e-waste recycling area were significantly higher than for the non-e-waste recycling area. However, there was no difference in plasma norepinephrine and heart rate between native children living in the non-e-waste recycling area and non-native children living in the non-e-waste recycling area. PM 2.5 , PM 10 , SO 2 and NO 2 data, over the 30-day and the 4-month average of pollution before the health examination, showed a positive association with plasma norepinephrine level. PM 2.5 , PM 10 , SO 2 , NO 2 and CO concentrations, over the 24 h of the day of the health examination, the 3 previous 24-hour periods before the health examination, and the 24 h after the health examination, were related to increase in heart rate. At the same time, plasma norepinephrine and heart rate on children in the high air pollution level group (≤50-m radius of family-run workshops) were higher than those in the low air pollution level group. Our results suggest that air pollution exposure in e-waste recycling areas could result in an increase in heart rate and plasma norepinephrine, implying e-waste air pollutant exposure impairs the SAM system in children. Copyright © 2018 Elsevier Ltd. All rights reserved.

Systolic Strain Abnormalities to Predict Hospital Readmission in Patients With Heart Failure and Normal Ejection Fraction

PubMed Central

Borer, Steven M.; Kokkirala, Aravind; O'Sullivan, David M.; Silverman, David I.

2011-01-01

Background Despite intensive investigation, the pathogenesis of heart failure with normal ejection fraction (HFNEF) remains unclear. We hypothesized that subtle abnormalities of systolic function might play a role, and that abnormal systolic strain and strain rate would provide a marker for adverse outcomes. Methods Patients of new CHF and left ventricular ejection fraction > 50% were included. Exclusion criteria were recent myocardial infarction, severe valvular heart disease, severe left ventricular hypertrophy (septum >1.8 cm), or a technically insufficient echocardiogram. Average peak systolic strain and strain rate were measured using an off-line grey scale imaging technique. Systolic strain and strain rate for readmitted patients were compared with those who remained readmission-free. Results One hundred consecutive patients with a 1st admission for HFNEF from January 1, 2004 through December 31, 2007, inclusive, were analyzed. Fifty two patients were readmitted with a primary diagnosis of heart failure. Systolic strain and strain rates were reduced in both study groups compared to controls. However, systolic strain did not differ significantly between the two groups (-11.7% for those readmitted compared with -12.9% for those free from readmission, P = 0.198) and systolic strain rates also were similar (-1.05 s-1 versus -1.09 s-1, P = 0.545). E/e’ was significantly higher in readmitted patients compared with those who remained free from readmission (14.5 versus 11.0, P = 0.013). E/e’ (OR 1.189, 95% CI 1.026-1.378; P = 0.021) was found to be an independent predictor for HFNEF readmission. Conclusions Among patients with new onset HFNEF, SS and SR rates are reduced compared with patients free of HFNEF, but do not predict hospital readmission. Elevated E/e’ is a predictor of readmission in these patients. PMID:28352395

Energy expenditure, heart rate response, and metabolic equivalents (METs) of adults taking part in children's games.

PubMed

Fischer, S L; Watts, P B; Jensen, R L; Nelson, J

2004-12-01

The needs of physical activity can be seen through the lack of numbers participating in regular physical activity as well as the increase in prevalence of certain diseases such as Type II diabetes (especially in children), cardiovascular diseases, and some cancers. With the increase in preventable diseases that are caused in part by a sedentary lifestyle, a closer look needs to be taken into the role of family interaction as a means of increasing physical activity for both adults and children. Because of the many benefits of physical activity in relation to health, a family approach to achieving recommended levels of physical activity may be quite applicable. Forty volunteers were recruited from the community (20 subjects and 20 children). The volunteers played 2 games: soccer and nerfball. Data was collected over 10 minutes (5 min per game). Expired air analysis was used to calculate energy expenditure and metabolic equivalents (METs). Descriptive statistics were calculated along with a regression analysis to determine differences between the 2 games, and an ACOVA to determine any significant effects of age, child age, gender, and physical activity level on the results. For both games, average heart rate measured approximately 88%max; average METs measured approximately 6, average energy expenditure measured approximately 40 kcal. S: This study showed that adults can achieve recommended physical activity levels through these specific activities if sustained for approximately 20 min.

Accurate measurement of imaging photoplethysmographic signals based camera using weighted average

NASA Astrophysics Data System (ADS)

Pang, Zongguang; Kong, Lingqin; Zhao, Yuejin; Sun, Huijuan; Dong, Liquan; Hui, Mei; Liu, Ming; Liu, Xiaohua; Liu, Lingling; Li, Xiaohui; Li, Rongji

2018-01-01

Imaging Photoplethysmography (IPPG) is an emerging technique for the extraction of vital signs of human being using video recordings. IPPG technology with its advantages like non-contact measurement, low cost and easy operation has become one research hot spot in the field of biomedicine. However, the noise disturbance caused by non-microarterial area cannot be removed because of the uneven distribution of micro-arterial, different signal strength of each region, which results in a low signal noise ratio of IPPG signals and low accuracy of heart rate. In this paper, we propose a method of improving the signal noise ratio of camera-based IPPG signals of each sub-region of the face using a weighted average. Firstly, we obtain the region of interest (ROI) of a subject's face based camera. Secondly, each region of interest is tracked and feature-based matched in each frame of the video. Each tracked region of face is divided into 60x60 pixel block. Thirdly, the weights of PPG signal of each sub-region are calculated, based on the signal-to-noise ratio of each sub-region. Finally, we combine the IPPG signal from all the tracked ROI using weighted average. Compared with the existing approaches, the result shows that the proposed method takes modest but significant effects on improvement of signal noise ratio of camera-based PPG estimated and accuracy of heart rate measurement.

Microwave influence on the isolated heart function. 2: Combined effect of radiation and some drugs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakhomov, A.G.; Dubovick, B.V.; Degtyariov, I.G.

1995-09-01

The combined effects of microwave radiation and some drugs were studied in an isolated frog auricle preparation. The experiments established that exposure to pulse-modulated 915 Mhz microwaves for up to 40 min had no effect on either the rate or the amplitude of spontaneous auricle twitches, unless the average absorbed power was high enough to produce preparation heating. Treatment of the preparation with saline containing (0.6--3.0) 10{sup {minus}5} M of propranolol or (0.5--1.5) 10{sup {minus}7} M of atropine altered neither its pacemaker nor its contractile functions; these drugs also had no effect when they were combined with nonthermal microwave irradiation.more » Caffeine (1 mM) strongly increased the average heart power, which was calculated as the product of twitch rate ad amplitude. The caffeine effect appeared to be significantly augmented (by about 15%, P<0.02) under exposure to burst-type pulsed microwaves (pulse width, 1.5 msec; pause, 2.5 msec; 8 pulses/burst, 16 bursts/s; average SAR, 8--10 W/kg). By itself, this modulation was not effective; the heating of the preparation and saline during exposure was approximately 0.1 C, which could not account for the detected changes. The experimental results demonstrate that caffeine treatment increases the microwave sensitivity of the frog auricle preparation and reveals primarily subthreshold, nonthermal microwave effect.« less

Elevated resting heart rate in heart transplant recipients: innocent bystander or adverse prognostic indicator?

PubMed

Wachter, S Blake; McCandless, Sean P; Gilbert, Edward M; Stoddard, Gregory J; Kfoury, Abdallah G; Reid, Bruce B; McKellar, Stephen H; Nativi-Nicolau, Jose; Saidi, Abdulfattah; Barney, Jacob; McCreath, Lauren; Koliopoulou, Antigone; Wright, Spencer E; Fang, James C; Stehlik, Josef; Selzman, Craig H; Drakos, Stavros G

2015-09-01

The elevated baseline heart rate (HR) of a heart transplant recipient has previously been considered inconsequential. However, we hypothesized that a resting HR above 100 beats per minute (bpm) may be associated with morbidity and mortality. The U.T.A.H. Cardiac Transplant Program studied patients who received a heart transplant between 2000 and 2011. Outpatient HR values for each patient were averaged during the first year post-transplant. The study cohort was divided into two groups: the tachycardic (TC) (HR > 100 bpm) and the non-TC group (HR ≤ 100 bpm) in which mortality, incidence of rejection, and cardiac allograft vasculopathy were compared. Three hundred and ten patients were included as follows: 73 in the TC and 237 in the non-TC group. The TC group had a higher risk of a 10-yr all-cause mortality (p = 0.004) and cardiovascular mortality (p = 0.044). After adjustment for donor and recipient characteristics in multivariable logistic regression analysis, the hazard ratio was 3.9, (p = 0.03, CI: 1.2-13.2) and 2.6 (p = 0.02, CI: 1.2-5.5) for cardiovascular mortality and all-cause mortality, respectively. Heart transplant recipients with elevated resting HR appear to have higher mortality than those with lower resting HR. Whether pharmacologically lowering the HR would result in better outcomes warrants further investigation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The effects of heart rate control in chronic heart failure with reduced ejection fraction.

PubMed

Grande, Dario; Iacoviello, Massimo; Aspromonte, Nadia

2018-07-01

Elevated heart rate has been associated with worse prognosis both in the general population and in patients with heart failure. Heart rate is finely modulated by neurohormonal signals and it reflects the balance between the sympathetic and the parasympathetic limbs of the autonomic nervous system. For this reason, elevated heart rate in heart failure has been considered an epiphenomenon of the sympathetic hyperactivation during heart failure. However, experimental and clinical evidence suggests that high heart rate could have a direct pathogenetic role. Consequently, heart rate might act as a pathophysiological mediator of heart failure as well as a marker of adverse outcome. This hypothesis has been supported by the observation that the positive effect of beta-blockade could be linked to the degree of heart rate reduction. In addition, the selective heart rate control with ivabradine has recently been demonstrated to be beneficial in patients with heart failure and left ventricular systolic dysfunction. The objective of this review is to examine the pathophysiological implications of elevated heart rate in chronic heart failure and explore the mechanisms underlying the effects of pharmacological heart rate control.

Self-reported quality of life and health among Björk-Shiley convexo-concave prosthetic heart valve patients.

PubMed

Signorello, L B; Kennedy, J A; Richmond, R A; Sieu, K L; Blot, W J; Harrison, D C

2001-03-01

The risk of fracture of Björk-Shiley convexo-concave (BSCC) prosthetic heart valves has resulted in consideration of prophylactic explantation and replacement for patients with high-risk valves. Little information exists on perceived quality of life, health status, and serious morbidity among BSCC patients, including those who have undergone explantation. Self-administered questionnaires were completed by a cohort of 585 BSCC patients who participated in an X-ray imaging study to detect precursors to valve fracture up to seven years (average 3.9 years) previously. Responses from 31 explant patients were contrasted with those from 554 BSCC patients in whom explant surgery was not attempted. Perceived quality of life and health status and risk of hospitalization after participating in the imaging study varied considerably among patients, but on average tended not to differ significantly between those with and without explants. A slightly greater proportion of explantees tended to report both improved health status and high rates of heart attack and pacemaker implantation. The health status of these patients was, in general, considerably worse than previously reported among valve implant patients. Over half the cohort were hospitalized during follow up, and half were unable to walk up more than one flight of stairs without shortness of breath. The less than optimal health status of most BSCC patients and relatively high rates of morbidity should be taken into account when considering potential explantation of the valves.

Seismocardiography-Based Cardiac Computed Tomography Gating Using Patient-Specific Template Identification and Detection.

PubMed

Yao, Jingting; Tridandapani, Srini; Wick, Carson A; Bhatti, Pamela T

2017-01-01

To more accurately trigger cardiac computed tomography angiography (CTA) than electrocardiography (ECG) alone, a sub-system is proposed as an intermediate step toward fusing ECG with seismocardiography (SCG). Accurate prediction of quiescent phases is crucial to prospectively gating CTA, which is susceptible to cardiac motion and, thus, can affect the diagnostic quality of images. The key innovation of this sub-system is that it identifies the SCG waveform corresponding to heart sounds and determines their phases within the cardiac cycles. Furthermore, this relationship is modeled as a linear function with respect to heart rate. For this paper, B-mode echocardiography is used as the gold standard for identifying the quiescent phases. We analyzed synchronous ECG, SCG, and echocardiography data acquired from seven healthy subjects (mean age: 31; age range: 22-48; males: 4) and 11 cardiac patients (mean age: 56; age range: 31-78; males: 6). On average, the proposed algorithm was able to successfully identify 79% of the SCG waveforms in systole and 68% in diastole. The simulated results show that SCG-based prediction produced less average phase error than that of ECG. It was found that the accuracy of ECG-based gating is more susceptible to increases in heart rate variability, while SCG-based gating is susceptible to high cycle to cycle variability in morphology. This pilot work of prediction using SCG waveforms enriches the framework of a comprehensive system with multiple modalities that could potentially, in real time, improve the image quality of CTA.

High energy deficit in an ultraendurance athlete in a 24-hour ultracycling race

PubMed Central

Rodríguez, Ferran A.; Iglesias, Xavier; Benítez, Adolfo; Marina, Míchel; Padullés, Josep M.; Torrado, Priscila; Vázquez, Jairo; Knechtle, Beat

2012-01-01

This case study examined the nutritional behavior and energy balance in an official finisher of a 24-hour ultracycling race. The food and beverages consumed by the cyclist were continuously weighed and recorded to estimate intake of energy, macronutrients, sodium, and caffeine. In addition, during the race, heart rate was continuously monitored. Energy expenditure was assessed using a heart rate–oxygen uptake regression equation obtained previously from a laboratory test. The athlete (39 years, 175.6 cm, 84.2 kg, maximum oxygen uptake, 64 mL/kg/min) cycled during 22 h 22 min, in which he completed 557.3 km with 8760 m of altitude at an average speed of 25.1 km/h. The average heart rate was 131 beats/min. Carbohydrates were the main macronutrient intake (1102 g, 13.1 g/kg); however, intake was below current recommendations. The consumption of protein and fat was 86 g and 91 g, respectively. He ingested 20.7 L (862 mL/h) of fluids, with sport drinks the main fluid used for hydration. Sodium concentration in relation to total fluid intake was 34.0 mmol/L. Caffeine consumption over the race was 231 mg (2.7 mg/kg). During the race, he expended 15,533 kcal. Total energy intake was 5571 kcal, with 4058 (73%) and 1513 (27%) kcal derived from solids and fluids, respectively. The energy balance resulted in an energy deficit of 9915 kcal. PMID:22481841

Predicting hospitalization due to worsening heart failure using daily weight measurement: analysis of the Trans-European Network-Home-Care Management System (TEN-HMS) study.

PubMed

Zhang, Jufen; Goode, Kevin M; Cuddihy, Paul E; Cleland, John G F

2009-04-01

We sought to test the utility of weight gain algorithms to predict episodes of worsening heart failure (WHF) using home-telemonitoring data collected as part of the TEN-HMS study. Simple rule-of-thumb (RoT) algorithms (i.e. 3 lbs in 1 day and 5 lbs in 3 days) and a moving average convergence divergence (MACD) algorithm were compared. WHF was defined as hospitalization for WHF or worsening of breathlessness or leg oedema. Of 168 patients, 45 were hospitalized with WHF and 76 were hospitalized for other reasons. On average, weight gain occurred in the 14 days prior to WHF hospitalizations but not in the 14 days prior to non-WHF hospitalizations [1.9 +/- 4.7 lbs (0.9 +/- 2.1 kg) vs. -0.4 +/- 2.5 lbs (-0.2 +/- 1.1 kg), P < 0.0001]. The true alerts rate was higher for the RoT algorithms compared with the MACD (58 and 65% vs. 20%). However, the RoT algorithms had much higher false alert rates (54 and 58% vs. 9%) rendering them of little practical use for predicting WHF events. A MACD algorithm is more specific but less sensitive than RoT when trying to predict episodes of WHF based on daily weight measurements. However, many episodes of WHF do not appear to be associated with weight gain and therefore telemonitoring of weight alone may not have great value for heart failure management.

Acute effects of Surya Namaskar on the cardiovascular & metabolic system.

PubMed

Mody, Bhavesh Surendra

2011-07-01

With the recent rise in obesity awareness and the increased understanding of the importance of physical activity in promoting overall health, greater emphasis has been placed on improving physical fitness to enhance quality of life. Surya Namaskar, a component of Hatha Yoga, has been practiced by Asian Indians for hundreds of years and is often used in place of a typical fitness program. It consists of a series of postures (asanas) that are repeated 12 times per round. Only one published study has looked specifically at Surya Namaskar, measuring the energy cost of individual asanas (Sinha et al., 2004). However, practitioners typically perform several rounds of the asanas during a session. To assess the cardiorespiratory and metabolic responses of four rounds of Surya Namaskar, a typical amount performed by practitioners, to determine its potential as a training and weight loss tool. Six healthy Asian Indian men and women (18-22 years) who had trained in Surya Namaskar for over two years participated in the study. Testing was completed in a single session lasting about 30 min. To measure heart rate and oxygen consumption while performing the four rounds, participants were connected to a heart rate monitor and the Oxycon Mobile Metabolic System. Participants exercised at 80% of age-predicted maximal heart rate (HRmax) during Round 2, 84% during Round 3, and 90% during Round 4. Average intensity during the four rounds was 80% HRmax, sufficient to elicit a cardiorespiratory training effect. Oxygen consumption averaged 26 ml/kg/min during each round, resulting in an energy expenditure of 230 kcals during a 30 min session for a 60 kg individual. Regular practice of Surya Namaskar may maintain or improve cardiorespiratory fitness, as well as promote weight management. Copyright © 2010 Elsevier Ltd. All rights reserved.

Use of technology to facilitate physical activity in children with autism spectrum disorders: A pilot study.

PubMed

Bittner, Melissa D; Rigby, B Rhett; Silliman-French, Lisa; Nichols, David L; Dillon, Suzanna R

2017-08-01

Deficits in social behavior and communication skills are correlated with reduced gross motor skills in children with autism spectrum disorders (ASD). The ExerciseBuddy application (EB app) was designed to communicate these motor skills to those with ASD and integrates evidence-based practices such as visual support and video modeling supported by The National Professional Development Center on Autism Spectrum Disorders. The purpose of this study was to determine the effectiveness of the EB app in facilitating increased physiologic responses to physical activity via a continuous measurement of energy expenditure and heart rate versus practice-style teaching methods in children with ASD. Six children, ages 5 to 10years, diagnosed with ASD were recruited. Each participant performed a variety of locomotor or object control skills as defined by the Test of Gross Motor Development-2 once per week for 4weeks. Motor skills were communicated and demonstrated using either practice-style teaching methods or the instructional section of the EB app. Energy expenditure and heart rate were measured continuously during each 12-minute session. A Wilcoxon signed-rank test was performed to assess any differences between the use of the app and practice-style teaching methods. The use of the EB app elicited greater values for peak energy expenditure (p=0.043) and peak heart rate response (p=0.028) while performing locomotor skills but no differences were observed while performing object control skills. Similarities were observed with average physiologic responses between the use of the EB app and practice-style teaching methods. The use of the EB app may allow for a greater peak physiologic response during more dynamic movements and a similar average cardiovascular and metabolic response when compared to practice-style teaching methods in children with ASD. Published by Elsevier Inc.

Electromyographic and kinematic analysis of graded treadmill walking and the implications for knee rehabilitation.

PubMed

Lange, G W; Hintermeister, R A; Schlegel, T; Dillman, C J; Steadman, J R

1996-05-01

Muscle activity, joints, angles, and heart rate during uphill walking were compared for application in knee rehabilitation. The objectives of this study were to quantify muscle activation levels at different treadmill grades and to determine the grade(s) at which knee range of motion would not further compromise the joint. Average and peak electromyographic activity of the quadriceps (vastus medialis oblique and vastus lateralis) and hamstrings (biceps femoris and medial hamstrings (semimembranosus/semitendinosus)] was recorded during walking at 0, 12, and 24% grade. Six subjects (age = 28.5 +/- 3.7 years, stature = 1.79 +/- .05 m, and mass = 74.7 +/- 7.9 kg) walked at self-selected speeds at each grade while ankle, knee and hip angles, heart rate, and electromyographic activity (surface electrodes) were recorded. Maximum voluntary contractions provided a relative reference for the electromyographic activity during walking. Average and peak electromyographic activity increased significantly across grades for the vastus medialis oblique (125 and 154%), vastus lateralis (109 and 139%), and biceps femoris (53 and 46%), but remained similar for the medial hamstrings. Maximum knee flexion at heel strike increased significantly with grade. Despite decreased self-selected speeds with increasing grade, there were significant increases in heart rate across grades. The results of this study provide a basic understanding of the quadriceps and hamstrings activity levels, lower extremity joint range of motion, and cardiovascular requirements of graded treadmill walking in normal subjects. The results also suggest that a grade just greater than 12% may be most beneficial for knee rehabilitation to minimize patellofemoral discomfort or potential strain on the anterior cruciate ligament. The benefits achieved through this functional activity encourage its implementation in rehabilitation and provide a basis for comparison with injured patients.

Passive fetal heart rate monitoring apparatus and method with enhanced fetal heart beat discrimination

NASA Technical Reports Server (NTRS)

Zahorian, Stephen A. (Inventor); Livingston, David L. (Inventor); Pretlow, III, Robert A. (Inventor)

1996-01-01

An apparatus for acquiring signals emitted by a fetus, identifying fetal heart beats and determining a fetal heart rate. Multiple sensor signals are outputted by a passive fetal heart rate monitoring sensor. Multiple parallel nonlinear filters filter these multiple sensor signals to identify fetal heart beats in the signal data. A processor determines a fetal heart rate based on these identified fetal heart beats. The processor includes the use of a figure of merit weighting of heart rate estimates based on the identified heart beats from each filter for each signal. The fetal heart rate thus determined is outputted to a display, storage, or communications channel. A method for enhanced fetal heart beat discrimination includes acquiring signals from a fetus, identifying fetal heart beats from the signals by multiple parallel nonlinear filtering, and determining a fetal heart rate based on the identified fetal heart beats. A figure of merit operation in this method provides for weighting a plurality of fetal heart rate estimates based on the identified fetal heart beats and selecting the highest ranking fetal heart rate estimate.

Passive fetal heart rate monitoring apparatus and method with enhanced fetal heart beat discrimination

NASA Technical Reports Server (NTRS)

Zahorian, Stephen A. (Inventor); Livingston, David L. (Inventor); Pretlow, Robert A., III (Inventor)

1994-01-01

An apparatus for acquiring signals emitted by a fetus, identifying fetal heart beats and determining a fetal heart rate is presented. Multiple sensor signals are outputted by a passive fetal heart rate monitoring sensor. Multiple parallel nonlinear filters filter these multiple sensor signals to identify fetal heart beats in the signal data. A processor determines a fetal heart rate based on these identified fetal heart beats. The processor includes the use of a figure of merit weighting of heart rate estimates based on the identified heart beats from each filter for each signal. The fetal heart rate thus determined is outputted to a display, storage, or communications channel. A method for enhanced fetal heart beat discrimination includes acquiring signals from a fetus, identifying fetal heart beats from the signals by multiple parallel nonlinear filtering, and determining a fetal heart rate based on the identified fetal heart beats. A figure of merit operation in this method provides for weighting a plurality of fetal heart rate estimates based on the identified fetal heart beats and selecting the highest ranking fetal heart rate estimate.

In vivo human cardiac shortening and lengthening velocity is region dependent and not coupled with heart rate: 'longitudinal' strain rate markedly underestimates apical contribution.

PubMed

Stöhr, Eric J; Stembridge, Mike; Esformes, Joseph I

2015-04-20

What is the central question of this study? Regulation of cardiac function is typically achieved by changes in heart rate (HR) and cardiac shortening velocity (strain rate; SR), but their interdependence in vivo remains poorly understood. What is the main finding and its importance? Using resistance exercise to increase heart rate and arterial resistance physiologically in humans and measuring regional cardiac SR (at the base and apex), we found that HR and SR were not strictly coupled because SR at the base and apex responded differently, despite the same HR. Importantly, our data show that the region-averaged 'longitudinal' SR, which is currently popular in the clinical setting, markedly underestimates the contribution of the apex. The fundamental importance of cardiac shortening and lengthening velocity (i.e. strain rate; SR) has been demonstrated in vitro. Currently, the interdependence between in vivo SR and HR is poorly understood because studies have typically assessed region-averaged 'longitudinal' strain rate, which is likely to underestimate the apical contribution, and have used non-physiological interventions that may also have been influenced by multicollinearity caused by concomitant reductions in arterial resistance. Resistance exercise acutely raises HR, blood pressure and arterial resistance and transiently disassociates these cardiovascular factors following exercise. Therefore, we measured SR, HR, blood pressure and arterial resistance in nine healthy men (aged 20 ± 1 years) immediately before, during and after double-leg-press exercise at 30 and 60% of maximal strength. Resistance exercise caused a disproportionate SR response at the left ventricular base and apex (interaction effect, P < 0.05). Consequently, associations between HR and regional peak SR were inconsistent and mostly very weak (r(2)  = 0.0004-0.24). Likewise, the areas under the curve for systolic and diastolic SR and their relationship with systolic and diastolic duration were variable and weak. Importantly, region-averaged 'longitudinal' SR was identical to basal SR, thus, markedly underestimating the apical contribution. In conclusion, in vivo HR and SR are not strictly coupled in healthy humans, which is explained by the region-specific responses of SR that are not captured by 'longitudinal SR'. This novel observation emphasizes the independent role of in vivo SR in overall cardiac function during stress and may cause a 'revival' of SR as a marker of regional left ventricular (dys)function. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

Southeast PAVE PAWS Radar System. Environmental Assessment.

DTIC Science & Technology

1983-03-01

reported, including fatigue, irritability, sleepiness, partial loss of memory, lower heart- beat rates, hypertension, hypotension, cardiac pain, and...Because such audiograms do not test hearing above 8 klz, binaural hearing thresholds were also determined for seven of the subjects for frequencies...perception and hearing ability above 8 kl:z as determined from the binaural thresholds. The average threshold pulse power density for 15-microsecond

beta-Blockade used in precision sports: effect on pistol shooting performance.

PubMed

Kruse, P; Ladefoged, J; Nielsen, U; Paulev, P E; Sørensen, J P

1986-08-01

In a double-blind cross-over study of 33 marksmen (standard pistol, 25 m) the adrenergic beta 1-receptor blocker, metoprolol, was compared to placebo. Metoprolol obviously improved the pistol shooting performance compared with placebo. Shooting improved by 13.4% of possible improvement (i.e., 600 points minus actual points obtained) as an average (SE = 4%, 2P less than 0.002). The most skilled athletes demonstrated the clearest metoprolol improvement. We found no correlation between the shooting improvement and changes in the cardiovascular variables (i.e., changes of heart rate and systolic blood pressure) and no correlation to the estimated maximum O2 uptake. The shooting improvement is an effect of metoprolol on hand tremor. Emotional increase of heart rate and systolic blood pressure seem to be a beta 1-receptor phenomenon.

Personal coronary risk profiles modify autonomic nervous system responses to air pollution.

PubMed

Chen, Jiu-Chiuan; Stone, Peter H; Verrier, Richard L; Nearing, Bruce D; MacCallum, Gail; Kim, Jee-Young; Herrick, Robert F; You, Jinhong; Zhou, Haibo; Christiani, David C

2006-11-01

We investigated whether PM2.5-mediated autonomic modulation depends on individual coronary risk profiles. Five-minute average heart rate (HR) and heart rate variability (HRV, including standard deviation of normal-to-normal intervals [SDNN], square root of the mean squared differences of successive NN intervals [rMSSD], high frequency [HF]) were measured from 24-hour ambulatory electrocardiograms, and personal PM(2.5) exposures were monitored in a prospective study of 10 male boilermakers (aged 34.3 +/- 8.1 years). We used the Framingham score to classify individuals into low (score = 1-3) and high (score = 5-6) risk categories. Mixed-effect models were used for statistical analyses. Each 1-mg/m(3) increase in the preceding 4-hour moving average PM(2.5) was associated with HR increase (5.3 beats/min) and HRV reduction (11.7%, confidence interval [CI] = 6.2-17.1% for SDNN; 11.1%, CI = 3.1-19.1% for rMSSD; 16.6%, CI = 1.5-31.7% for HF). Greater responses (2- to 4-fold differences) were observed in high-risk subjects than in low-risk subjects. Our study suggests that adverse autonomic responses to metal particulate are aggravated in workers with higher coronary risk profiles.

Spatial probabilistic pulsatility model for enhancing photoplethysmographic imaging systems

NASA Astrophysics Data System (ADS)

Amelard, Robert; Clausi, David A.; Wong, Alexander

2016-11-01

Photoplethysmographic imaging (PPGI) is a widefield noncontact biophotonic technology able to remotely monitor cardiovascular function over anatomical areas. Although spatial context can provide insight into physiologically relevant sampling locations, existing PPGI systems rely on coarse spatial averaging with no anatomical priors for assessing arterial pulsatility. Here, we developed a continuous probabilistic pulsatility model for importance-weighted blood pulse waveform extraction. Using a data-driven approach, the model was constructed using a 23 participant sample with a large demographic variability (11/12 female/male, age 11 to 60 years, BMI 16.4 to 35.1 kg·m-2). Using time-synchronized ground-truth blood pulse waveforms, spatial correlation priors were computed and projected into a coaligned importance-weighted Cartesian space. A modified Parzen-Rosenblatt kernel density estimation method was used to compute the continuous resolution-agnostic probabilistic pulsatility model. The model identified locations that consistently exhibited pulsatility across the sample. Blood pulse waveform signals extracted with the model exhibited significantly stronger temporal correlation (W=35,p<0.01) and spectral SNR (W=31,p<0.01) compared to uniform spatial averaging. Heart rate estimation was in strong agreement with true heart rate [r2=0.9619, error (μ,σ)=(0.52,1.69) bpm].

Physical workload, trapezius muscle activity, and neck pain in nurses' night and day shifts: a physiological evaluation.

PubMed

Nicoletti, Corinne; Spengler, Christina M; Läubli, Thomas

2014-05-01

The purpose of this study was to compare physical workload, electromyography (EMG) of the trapezius muscle, neck pain and mental well-being at work between night and day shifts in twenty Swiss nurses. Work pulse (average increase of heart rate over resting heart rate) was lower during night (27 bpm) compared to day shifts (34 bpm; p < 0.01). Relative arm acceleration also indicated less physical activity during night (82% of average) compared to day shifts (110%; p < 0.01). Rest periods were significantly longer during night shifts. Trapezius muscle rest time was longer during night (13% of shift duration) than day shifts (7%; p < 0.01) and the 50th percentile of EMG activity was smaller (p = 0.02), indicating more opportunities for muscle relaxation during night shifts. Neck pain and mental well-being at work were similar between shifts. Subjective perception of burden was similar between shifts despite less physical burden at night, suggesting there are other contributing factors. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Impact of Music on Pediatric Oncology Outpatients

PubMed Central

KEMPER, KATHI J.; HAMILTON, CRAIG A.; MCLEAN, THOMAS W.; LOVATO, JAMES

2013-01-01

Music is widely used to enhance well-being. We wished to assess music’s effect on pediatric oncology outpatients. Patients who had leukemia and were in maintenance or consolidation outpatient treatment served as their own control at two visits. At visit 1, children rested for 20 min; at visit 2, for 20 min they listened to music designed to increase vitality and improve heart rate variability (HRV). At both visits, parents completed before and after treatment visual analog scales (VAS) of their child’s relaxation, well-being, vitality, anxiety, stress, and depression; patients’ heart rates were monitored during treatments to calculate HRV. The 47 patients with complete VAS data and 34 patients with usable HRV data were similar. At baseline, VAS scores for negative states were low (average <2.5 of 10) and positive states were high (average 7> of 10). Relaxation improved more with music than rest (p < 0.01). The HRV parasympathetic parameter was significantly lower with music than rest. No other differences were significant. Further studies are needed to better delineate the relationship between subjective and objective measures of well-being among patients who are not in severe distress. PMID:18391850

BIOPHYSICAL CHARACTERISATION OF THE UNDER-APPRECIATED AND IMPORTANT RELATIONSHIP BETWEEN HEART RATE VARIABILITY AND HEART RATE

PubMed Central

Monfredi, Oliver; Lyashkov, Alexey E; Johnsen, Anne-Berit; Inada, Shin; Schneider, Heiko; Wang, Ruoxi; Nirmalan, Mahesh; Wisloff, Ulrik; Maltsev, Victor A; Lakatta, Edward G; Zhang, Henggui; Boyett, Mark R

2014-01-01

Heart rate variability (beat-to-beat changes in the RR interval) has attracted considerable attention over the last 30+ years (PubMed currently lists >17,000 publications). Clinically, a decrease in heart rate variability is correlated to higher morbidity and mortality in diverse conditions, from heart disease to foetal distress. It is usually attributed to fluctuation in cardiac autonomic nerve activity. We calculated heart rate variability parameters from a variety of cardiac preparations (including humans, living animals, Langendorff-perfused heart and single sinoatrial nodal cell) in diverse species, combining this with data from previously published papers. We show that regardless of conditions, there is a universal exponential decay-like relationship between heart rate variability and heart rate. Using two biophysical models, we develop a theory for this, and confirm that heart rate variability is primarily dependent on heart rate and cannot be used in any simple way to assess autonomic nerve activity to the heart. We suggest that the correlation between a change in heart rate variability and altered morbidity and mortality is substantially attributable to the concurrent change in heart rate. This calls for re-evaluation of the findings from many papers that have not adjusted properly or at all for heart rate differences when comparing heart rate variability in multiple circumstances. PMID:25225208

The physiological demands of horseback mustering when wearing an equestrian helmet.

PubMed

Taylor, Nigel A S; Caldwell, Joanne N; Dyer, Rodd

2008-09-01

The hottest months on northern Australian cattle stations are from September to November, and it is during these months that horseback cattle mustering occurs. Stockmen wear clothing that restricts heat loss, and protective helmets have recently been introduced. Anecdotal evidence points to the possibility that helmets may increase the probability of developing heat illness, or reducing workplace performance. In this project, we quantified the working (thermal) environment on such cattle stations, and measured the metabolic demands on, and concurrent physiological strain in stockmen during mustering, whilst wearing an equestrian helmet. During horseback work, the average heart rate was 102.0 beats min(-1) (SD 14.0), with almost 90% of the time (238 min) spent working at intensities <50% of the heart rate reserve. The projected metabolic heat production during mustering ranged between 178 and 333 W (women), and between 212 and 542 W (men). The average core temperature was 37.6 degrees C, while the mean skin temperature averaged 34.1 degrees C. It was concluded that the working environment is, on average, thermally uncompensable during the mustering season. However, horseback mustering per se is a relatively low-intensity activity, interspersed with short periods of high-intensity work. This activity level was reflected within core temperatures, which rarely climbed above values associated with light-moderate exercise. Thus, whilst the climatic state was uncompensable, stockmen used behavioural strategies to minimise the risk of heat illness. Finally, it was observed that the helmet, though unpleasant to wear, did not appear to increase thermal strain in a manner that would disadvantage stockmen.

Associations between Changes in City and Address Specific Temperature and QT Interval - The VA Normative Aging Study

PubMed Central

Mehta, Amar J.; Kloog, Itai; Zanobetti, Antonella; Coull, Brent A.; Sparrow, David; Vokonas, Pantel; Schwartz, Joel

2014-01-01

Background The underlying mechanisms of the association between ambient temperature and cardiovascular morbidity and mortality are not well understood, particularly for daily temperature variability. We evaluated if daily mean temperature and standard deviation of temperature was associated with heart rate-corrected QT interval (QTc) duration, a marker of ventricular repolarization in a prospective cohort of older men. Methods This longitudinal analysis included 487 older men participating in the VA Normative Aging Study with up to three visits between 2000–2008 (n = 743). We analyzed associations between QTc and moving averages (1–7, 14, 21, and 28 days) of the 24-hour mean and standard deviation of temperature as measured from a local weather monitor, and the 24-hour mean temperature estimated from a spatiotemporal prediction model, in time-varying linear mixed-effect regression. Effect modification by season, diabetes, coronary heart disease, obesity, and age was also evaluated. Results Higher mean temperature as measured from the local monitor, and estimated from the prediction model, was associated with longer QTc at moving averages of 21 and 28 days. Increased 24-hr standard deviation of temperature was associated with longer QTc at moving averages from 4 and up to 28 days; a 1.9°C interquartile range increase in 4-day moving average standard deviation of temperature was associated with a 2.8 msec (95%CI: 0.4, 5.2) longer QTc. Associations between 24-hr standard deviation of temperature and QTc were stronger in colder months, and in participants with diabetes and coronary heart disease. Conclusion/Significance In this sample of older men, elevated mean temperature was associated with longer QTc, and increased variability of temperature was associated with longer QTc, particularly during colder months and among individuals with diabetes and coronary heart disease. These findings may offer insight of an important underlying mechanism of temperature-related cardiovascular morbidity and mortality in an older population. PMID:25238150

Assessing Heart Rate in Physical Education. Assessment Series: K-12 Physical Education.

ERIC Educational Resources Information Center

Buck, Marilyn M.

This guide discusses the assessment of heart rate and, in particular, the assessment of heart rate using a heart monitor. Part 1, "Foundation for the Use of Heart Rate," reviews literature about heart rate assessment and heart rate monitors, offering an overview of national guidelines for physical activity. It focuses on the importance…

Medical Monitoring During Firefighter Incident Scene Rehabilitation.

PubMed

Barr, David A; Haigh, Craig A; Haller, Jeannie M; Smith, Denise L

2016-01-01

The objective of this study was to retrospectively investigate aspects of medical monitoring, including medical complaints, vital signs at entry, and vital sign recovery, in firefighters during rehabilitation following operational firefighting duties. Incident scene rehabilitation logs obtained over a 5-year span that included 53 incidents, approximately 40 fire departments, and more than 530 firefighters were reviewed. Only 13 of 694 cases involved a firefighter reporting a medical complaint. In most cases, vital signs were similar between firefighters who registered a complaint and those who did not. On average, heart rate was 104 ± 23 beats·min(-1), systolic blood pressure was 132 ± 17 mmHg, diastolic blood pressure was 81 ± 12 mmHg, and respiratory rate was 19 ± 3 breaths·min(-1) upon entry into rehabilitation. At least two measurements of heart rate, systolic blood pressure, diastolic blood pressure, and respiratory rate were obtained for 365, 383, 376, and 160 cases, respectively. Heart rate, systolic and diastolic blood pressures, and respiratory rate decreased significantly (p < 0.001) during rehabilitation. Initial vital signs and changes in vital signs during recovery were highly variable. Data from this study indicated that most firefighters recovered from the physiological stress of firefighting without any medical complaint or symptoms. Furthermore, vital signs were within fire service suggested guidelines for release within 10 or 20 minutes of rehabilitation. The data suggested that vital signs of firefighters with medical symptoms were not significantly different from vital signs of firefighters who had an unremarkable recovery.

A three-lead, programmable, and microcontroller-based electrocardiogram generator with frequency domain characteristics of heart rate variability.

PubMed

Wei, Ying-Chieh; Wei, Ying-Yu; Chang, Kai-Hsiung; Young, Ming-Shing

2012-04-01

The objective of this study is to design and develop a programmable electrocardiogram (ECG) generator with frequency domain characteristics of heart rate variability (HRV) which can be used to test the efficiency of ECG algorithms and to calibrate and maintain ECG equipment. We simplified and modified the three coupled ordinary differential equations in McSharry's model to a single differential equation to obtain the ECG signal. This system not only allows the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters to be adjusted, but can also be used to adjust the very low frequency, low frequency, and high frequency components of HRV frequency domain characteristics. The system can be tuned to function with HRV or not. When the HRV function is on, the average heart rate can be set to a value ranging from 20 to 122 beats per minute (BPM) with an adjustable variation of 1 BPM. When the HRV function is off, the heart rate can be set to a value ranging from 20 to 139 BPM with an adjustable variation of 1 BPM. The amplitude of the ECG signal can be set from 0.0 to 330 mV at a resolution of 0.005 mV. These parameters can be adjusted either via input through a keyboard or through a graphical user interface (GUI) control panel that was developed using LABVIEW. The GUI control panel depicts a preview of the ECG signal such that the user can adjust the parameters to establish a desired ECG morphology. A complete set of parameters can be stored in the flash memory of the system via a USB 2.0 interface. Our system can generate three different types of synthetic ECG signals for testing the efficiency of an ECG algorithm or calibrating and maintaining ECG equipment. © 2012 American Institute of Physics

The Effect of Adenotonsillectomy for Childhood Sleep Apnea on Cardiometabolic Measures

PubMed Central

Quante, Mirja; Wang, Rui; Weng, Jia; Rosen, Carol L.; Amin, Raouf; Garetz, Susan L.; Katz, Eliot; Paruthi, Shalini; Arens, Raanan; Muzumdar, Hiren; Marcus, Carole L.; Ellenberg, Susan; Redline, Susan

2015-01-01

Study Objectives: Obstructive sleep apnea syndrome (OSAS) has been associated with cardiometabolic disease in adults. In children, this association is unclear. We evaluated the effect of early adenotonsillectomy (eAT) for treatment of OSAS on blood pressure, heart rate, lipids, glucose, insulin, and C-reactive protein. We also analyzed whether these parameters at baseline and changes at follow-up correlated with polysomnographic indices. Design: Data collected at baseline and 7-mo follow-up were analyzed from a randomized controlled trial, the Childhood Adenotonsillectomy Trial (CHAT). Setting: Clinical referral setting from multiple centers. Participants: There were 464 children, ages 5 to 9.9 y with OSAS without severe hypoxemia. Interventions: Randomization to eAT or Watchful Waiting with Supportive Care (WWSC). Measurements and Results: There was no significant change of cardiometabolic parameters over the 7-mo interval in the eAT group compared to WWSC group. However, overnight heart rate was incrementally higher in association with baseline OSAS severity (average heart rate increase of 3 beats per minute [bpm] for apnea-hypopnea index [AHI] of 2 versus 10; [standard error = 0.60]). Each 5-unit improvement in AHI and 5 mmHg improvement in peak end-tidal CO2 were estimated to reduce heart rate by 1 and 1.5 bpm, respectively. An increase in N3 sleep also was associated with small reductions in systolic blood pressure percentile. Conclusions: There is little variation in standard cardiometabolic parameters in children with obstructive sleep apnea syndrome (OSAS) but without severe hypoxemia at baseline or after intervention. Of all measures, overnight heart rate emerged as the most sensitive parameter of pediatric OSAS severity. Clinical Trial Registration: Clinicaltrials.gov (#NCT00560859) Citation: Quante M, Wang R, Weng J, Rosen CL, Amin R, Garetz SL, Katz E, Paruthi S, Arens R, Muzumdar H, Marcus CL, Ellenberg S, Redline S. The effect of adenotonsillectomy for childhood sleep apnea on cardiometabolic measures. SLEEP 2015;38(9):1395–1403. PMID:25669177

A three-lead, programmable, and microcontroller-based electrocardiogram generator with frequency domain characteristics of heart rate variability

NASA Astrophysics Data System (ADS)

Wei, Ying-Chieh; Wei, Ying-Yu; Chang, Kai-Hsiung; Young, Ming-Shing

2012-04-01

The objective of this study is to design and develop a programmable electrocardiogram (ECG) generator with frequency domain characteristics of heart rate variability (HRV) which can be used to test the efficiency of ECG algorithms and to calibrate and maintain ECG equipment. We simplified and modified the three coupled ordinary differential equations in McSharry's model to a single differential equation to obtain the ECG signal. This system not only allows the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters to be adjusted, but can also be used to adjust the very low frequency, low frequency, and high frequency components of HRV frequency domain characteristics. The system can be tuned to function with HRV or not. When the HRV function is on, the average heart rate can be set to a value ranging from 20 to 122 beats per minute (BPM) with an adjustable variation of 1 BPM. When the HRV function is off, the heart rate can be set to a value ranging from 20 to 139 BPM with an adjustable variation of 1 BPM. The amplitude of the ECG signal can be set from 0.0 to 330 mV at a resolution of 0.005 mV. These parameters can be adjusted either via input through a keyboard or through a graphical user interface (GUI) control panel that was developed using LABVIEW. The GUI control panel depicts a preview of the ECG signal such that the user can adjust the parameters to establish a desired ECG morphology. A complete set of parameters can be stored in the flash memory of the system via a USB 2.0 interface. Our system can generate three different types of synthetic ECG signals for testing the efficiency of an ECG algorithm or calibrating and maintaining ECG equipment.

Comparing the Effects of Rest and Massage on Return to Homeostasis Following Submaximal Aerobic Exercise: a Case Study

PubMed Central

Resnick, Portia B.

2016-01-01

Introduction Postexercise massage can be used to help promote recovery from exercise on the cellular level, as well as systemically by increasing parasympathetic activity. No studies to date have been done to assess the effects of massage on postexercise metabolic changes, including excess postexercise oxygen consumption (EPOC). The purpose of this study was to compare the effects of massage recovery and resting recovery on a subject’s heart rate variability and selected metabolic effects following a submaximal treadmill exercise session. Methods One healthy 24-year-old female subject performed 30 minutes of submaximal treadmill exercise prior to resting or massage recovery sessions. Metabolic data were collected throughout the exercise sessions and at three 10 minute intervals postexercise. Heart rate variability was evaluated for 10 minutes after each of two 30-minute recovery sessions, either resting or massage. Results Heart rate returned to below resting levels (73 bpm) with 30 and 60 minutes of massage recovery (72 bpm and 63 bpm, respectively) compared to 30 and 60 minutes of resting recovery (77 bpm and 74 bpm, respectively). Heart rate variability data showed a more immediate shift to the parasympathetic state following 30 minutes of massage (1.152 LF/HF ratio) versus the 30-minute resting recovery (6.91 LF/HF ratio). It took 60 minutes of resting recovery to reach similar heart rate variability levels (1.216 LF/HF) found after 30 minutes of massage. Ventilations after 30 minutes of massage recovery averaged 7.1 bpm compared to 17.9 bpm after 30 minutes of resting recovery. Conclusions No differences in EPOC were observed through either the resting or massage recovery based on the metabolic data collected. Massage was used to help the subject shift into parasympathetic activity more quickly than rest alone following a submaximal exercise session. PMID:26977215

Profile of Heart Donors from the Human Valve Bank of the Santa Casa de Misericórdia de Curitiba.

PubMed

Ferreira, Renata Maria; da Costa, Marise Teresinha Brenner Affonso; Canciglieri Junior, Osiris; Sant'Anna, Ângelo Márcio Oliveira

2016-04-01

Human heart valves are used as replacement valves and have satisfactory functional results compared with conventional prostheses. Characterize the profile of effective heart donors from the human valve bank of the santa casa de misericórdia de curitiba and analyze the association between the profile variables. It consists of a retrospective and quantitative study of electronic medical records from heart donors for heart valves. every heart donation made to the bank between january 2004 and december 2014 was studied. 2,149 donations were analyzed, from donors aged 0 to 71 years old, with an average of 34.9 ± 15.03 years old. most donors were male 65.7% (n=1,411) and 34.3% (n=738) were female. among the most frequent causes of the donors' death are trauma at 53% (n=1,139) and cerebral vascular accident at 34.2% (n=735). there was significant statistical association between the analyzed variables. There has been an improvement in brazil's donation rate, being essential that the tissue banks work together with the state and federal district centers for notification, procurement and distribution of organs in order to increase the number of donors.

A 4-Week Intervention Involving Mobile-Based Daily 6-Minute Micro-Sessions of Functional High-Intensity Circuit Training Improves Strength and Quality of Life, but Not Cardio-Respiratory Fitness of Young Untrained Adults.

PubMed

Sperlich, Billy; Hahn, Lea-Sofie; Edel, Antonia; Behr, Tino; Helmprobst, Julian; Leppich, Robert; Wallmann-Sperlich, Birgit; Holmberg, Hans-Christer

2018-01-01

The present study was designed to assess the psycho-physiological responses of physically untrained individuals to mobile-based multi-stimulating, circuit-like, multiple-joint conditioning (Circuit HIIT ) performed either once (1xCircuit HIIT ) or twice (2xCircuit HIIT ) daily for 4 weeks. In this single-center, two-arm randomized, controlled study, 24 men and women (age: 25 ± 5 years) first received no training instructions for 4 weeks and then performed 4 weeks of either 1xCircuit HIIT or 2xCircuit HIIT (5 men and 7 women in each group) daily. The 1xCircuit HIIT and 2xCircuit HIIT participants carried out 90.7 and 85.7% of all planned training sessions, respectively, with average heart rates during the 6-min sessions of 74.3 and 70.8% of maximal heart rate. Body, fat and fat-free mass, and metabolic rate at rest did not differ between the groups or between time-points of measurement. Heart rate while running at 6 km⋅h -1 declined after the intervention in both groups. Submaximal and peak oxygen uptake, the respiratory exchange ratio and heart rate recovery were not altered by either intervention. The maximal numbers of push-ups, leg-levers, burpees, 45°-one-legged squats and 30-s skipping, as well as perception of general health improved in both groups. Our 1xCircuit HIIT or 2xCircuit HIIT interventions improved certain parameters of functional strength and certain dimensions of quality of life in young untrained individuals. However, they were not sufficient to enhance cardio-respiratory fitness, in particular peak oxygen uptake.

Hospital Use of Observation Stays: Cross-sectional Study of the Impact on Readmission Rates.

PubMed

Venkatesh, Arjun K; Wang, Changqin; Ross, Joseph S; Altaf, Faseeha K; Suter, Lisa G; Vellanky, Smitha; Grady, Jacqueline N; Bernheim, Susannah M

2016-12-01

The Centers for Medicare and Medicaid Services publicly reports hospital risk-standardized readmission rates (RSRRs) as a measure of quality and performance; mischaracterizations may occur because observation stays are not captured by current measures. To describe variation in hospital use of observation stays, the relationship between hospitals observation stay use and RSRRs. Cross-sectional analysis of Medicare fee-for-service beneficiaries discharged after acute myocardial infarction (AMI), heart failure, or pneumonia between July 2011 and June 2012. We calculated 3 hospital-specific 30-day outcomes: (1) observation rate, the proportion of all discharges followed by an observation stay without a readmission; (2) observation proportion, the proportion of observation stays among all patients with an observation stay or readmission; and (3) RSRR. For all 3 conditions, hospitals' observation rates were <2.5% and observation proportions were <12%, although there was variation across hospitals, including 28% of hospital with no observation stay use for AMI, 31% for heart failure, and 43% for pneumonia. There were statistically significant, but minimal, correlations between hospital observation rates and RSRRs: AMI (r=-0.02), heart failure (r=-0.11), and pneumonia (r=-0.02) (P<0.001). There were modest inverse correlations between hospital observation proportion and RSRR: AMI (r=-0.34), heart failure (r=-0.26), and pneumonia (r=-0.21) (P<0.001). If observation stays were included in readmission measures, <4% of top performing hospitals would be recategorized as having average performance. Hospitals' observation stay use in the postdischarge period is low, but varies widely. Despite modest correlation between the observation proportion and RSRR, counting observation stays in readmission measures would minimally impact public reporting of performance.

[Mortality rates of circulatory system diseases and malignant neoplasms in Zagreb population younger than sixty-five--call for alarm].

PubMed

Vizintin, Marina Polić; Mrcela, Nada Tomasović; Kovacić, Luka

2012-12-01

The aim of this work was to analyze the public health indicators for circulatory heart diseases and malignant neoplasms in the population younger than 65 in the City of Zagreb, Croatia, and compare them with the European Union (EU) countries. The purpose was to evaluate the situation and propose the public health preventive measures. The study population were Zagreb citizens aged 0-64 according to the 2001 census. Total Zagreb population was 779145, making 17.6% of total Croatian population. Data from the Croatian Bureau of Statistics and Dr Andrija Stampar Institute of Public Health were used. The standardized 0-64 mortality rates of the selected diseases 2006-2010 were used in the analysis. In 2010, the standardized mortality rates of all analyzed diseases were significantly higher in Zagreb population aged 0-64 than the EU averages except for cervical cancer. In 2010, the mortality rates in Zagreb population aged 0-64 were as follows: circulatory system diseases 61.22, ischemic heart disease 28.99, cerebrovascular diseases 12.51, malignant neoplasms 94.69, tracheal and lung cancer 24.92, breast cancer 21.08 and cervical cancer 2.05. Standardized mortality rates in Zagreb population aged 0-64 for circulatory system were lower than for Croatia (61.22 vs. 63.25), but higher for malignant neoplasms (94.69 vs. 91.2), except for cervical cancer (2.05 vs. 3.14). High standardized mortality rates for the selected diseases in the City of Zagreb, Croatia, were observed. The rates were higher in Zagreb population compared to EU averages except for cervical cancer. This situation urges revision of the public health strategy and implementation of more intensive preventive and screening measures to reduce the risk factors.

Performance Under Stress Conditions During Multidisciplinary Team Immersive Pediatric Simulations.

PubMed

Ghazali, Daniel Aiham; Darmian-Rafei, Ivan; Ragot, Stéphanie; Oriot, Denis

2018-06-01

The primary objective was to determine whether technical and nontechnical performances were in some way correlated during immersive simulation. Performance was measured among French Emergency Medical Service workers at an individual and a team level. Secondary objectives were to assess stress response through collection of physiologic markers (salivary cortisol, heart rate, the proportion derived by dividing the number of interval differences of successive normal-to-normal intervals > 50 ms by the total number of normal-to-normal intervals [pNN50], low- and high-frequency ratio) and affective data (self-reported stress, confidence, and dissatisfaction), and to correlate them to performance scores. Prospective observational study performed as part of a larger randomized controlled trial. Medical simulation laboratory. Forty-eight participants distributed among 12 Emergency Medical System teams. Individual and team performance measures and individual stress response were assessed during a high-fidelity simulation. Technical performance was assessed by the intraosseous access performance scale and the Team Average Performance Assessment Scale; nontechnical performance by the Behavioral Assessment Tool for leaders, and the Clinical Teamwork Scale. Stress markers (salivary cortisol, heart rate, pNN50, low- and high-frequency ratio) were measured both before (T1) and after the session (T2). Participants self-reported stress before and during the simulation, self-confidence, and perception of dissatisfaction with team performance, rated on a scale from 0 to 10. Scores (out of 100 total points, mean ± SD) were intraosseous equals to 65.6 ± 14.4, Team Average Performance Assessment Scale equals to 44.6 ± 18.1, Behavioral Assessment Tool equals to 49.5 ± 22.0, Clinical Teamwork Scale equals to 50.3 ± 18.5. There was a strong correlation between Behavioral Assessment Tool and Clinical Teamwork Scale (Rho = 0.97; p = 0.001), and Behavioral Assessment Tool and Team Average Performance Assessment Scale (Rho = 0.73; p = 0.02). From T1 to T2, all stress markers (salivary cortisol, heart rate, pNN50, and low- and high-frequency ratio) displayed an increase in stress level (p < 0.001 for all). Self-confidence was positively correlated with performance (Clinical Teamwork Scale: Rho = 0.47; p = 0.001, Team Average Performance Assessment Scale: Rho = 0.46; p = 0.001). Dissatisfaction was negatively correlated with performance (Rho = -0.49; p = 0.0008 with Behavioral Assessment Tool, Rho = -0.47; p = 0.001 with Clinical Teamwork Scale, Rho = -0.51; p = 0.0004 with Team Average Performance Assessment Scale). No correlation between stress response and performance was found. There was a positive correlation between leader (Behavioral Assessment Tool) and team (Clinical Teamwork Scale and Team Average Performance Assessment Scale) performances. These performance scores were positively correlated with self-confidence and negatively correlated with dissatisfaction.

Cardiopulmonary Response to Videogaming: Slaying Monsters Using Motion Sensor Versus Joystick Devices.

PubMed

Sherman, Jeffrey D; Sherman, Michael S; Heiman-Patterson, Terry

2014-10-01

Replacing physical activity with videogaming has been implicated in causing obesity. Studies have shown that using motion-sensing controllers with activity-promoting videogames expends energy comparable to aerobic exercise; however, effects of motion-sensing controllers have not been examined with traditional (non-exercise-promoting) videogames. We measured indirect calorimetry and heart rate in 14 subjects during rest and traditional videogaming using motion sensor and joystick controllers. Energy expenditure was higher while subjects were playing with the motion sensor (1.30±0.32 kcal/kg/hour) than with the joystick (1.07±0.26 kcal/kg/hour; P<0.01) or resting (0.91±0.24 kcal/kg/hour; P<0.01). Oxygen consumption during videogaming averaged 15.7 percent of predicted maximum for the motion sensor and 11.8 percent of maximum for the joystick. Minute ventilation was higher playing with the motion sensor (10.7±3.5 L/minute) than with the joystick (8.6±1.8 L/minute; P<0.02) or resting (6.7±1.4 L/minute; P<0.001), predominantly because of higher respiratory rates (15.2±4.3 versus 20.3±2.8 versus 20.4±4.2 beats/minute for resting, the joystick, and the motion sensor, respectively; P<0.001); tidal volume did not change significantly. Peak heart rate during gaming was 16.4 percent higher than resting (78.0±12.0) for joystick (90.1±15.0; P=0.002) and 17.4 percent higher for the motion sensor (91.6±14.1; P=0.002); mean heart rate did not differ significantly. Playing with a motion sensor burned significantly more calories than with a joystick, but the energy expended was modest. With both consoles, the increased respiratory rate without increasing tidal volume and the increased peak heart rate without increasing mean heart rate are consistent with psychological stimulation from videogaming, rather than a result of exercise. We conclude that using a motion sensor with traditional videogames does not provide adequate energy expenditure to provide cardiovascular conditioning.

Comparıson of the Heart Rate and Blood Lactate Responses of Different Small Sided Games in Young Soccer Players.

PubMed

Köklü, Yusuf; Alemdaroğlu, Utku

2016-09-29

The purpose of this study was to compare the percentage of maximum heart rate (%HRmax), blood lactate (La - ), and rating of perceived exertion (RPE, CR-10) responses across different formats of small-sided games (SSG) in elite young soccer players. Fourteen players (average age 16.7 ± 0.6 years; height 177.6 ± 4.1 cm; body mass 66.3 ± 4.7 kg; average training age 6.7 ± 1.6 years; percentage of body fat 8.4 ± 2.6%) volunteered to perform the YoYo intermittent recovery test (level 1) and eight bouts of soccer drills including 2-a-side, 3-a-side, and 4-a-side games without goalkeepers in random order at two-day intervals. Heart rates were monitored throughout the SSGs, whereas the RPE and venous blood lactate were determined at the end of the last bout of each SSG. The differences in La - , %HRmax, and RPE either across the different SSGs or between the bouts were identified using 3 × 8 (games × exercise bouts) two-way analysis of variance with repeated measures. Significant differences were found in terms of La - , RPE, and %HRmax among the different types of SSG ( p ≤ 0.05). 3-a-side and 4-a-side games elicited significantly higher responses than 2-a-side games in terms of %HRmax ( p ≤ 0.05), whereas 4-a-side games resulted in significantly lower La - and RPE responses compared to 2-a-side and 3-a-side games. The results of this study show that physiological responses differ according to the numbers of players involved in small-sided games. Therefore, it can be concluded that 3-a-side and 4-a-side games could be more effective in improving high intensity aerobic performance than 2-a-side games, which in turn are more appropriate for developing anaerobic performance.

Fluid-electrolyte shifts and thermoregulation - Rest and work in heat with head cooling

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Van Beaumont, W.; Brock, P. J.; Montgomery, L. D.; Morse, J. T.; Shvartz, E.; Kravik, S.

1980-01-01

The effects of head cooling on thermoregulation and associated plasma fluid and electrolyte shifts during rest and submaximal exercise in the heat are investigated. Thermoregulatory responses and plasma volume were measured in four male subjects fitted with liquid-cooled neoprene headgear during 60 min of rest, 60 min of ergometer exercise at 45% maximal oxygen uptake and 30 min of recovery in the supine position at 40.1 C and 40% relative humidity. It is found that, compared to control responses, head cooling decreased thigh sweating and increased mean skin temperature at rest and attenuated increases in thigh sweating, heart rate, rectal temperature and ventilation during exercise. During recovery, cooling is observed to facilitate decreases in sweat rate, heart rate, rectal temperature and forearm blood flow and enhance the increase in average temperature. Cooling had no effect on plasma protein, osmotic or electrolyte shifts, and decreased plasma volume losses. The findings indicate the effectiveness of moderate head cooling for the improvement of human performance during exercise in heat.

Effect of uterine contractions on fetal heart rate in pregnancy: a prospective observational study.

PubMed

Sletten, Julie; Kiserud, Torvid; Kessler, Jörg

2016-10-01

The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40 weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8 h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7 beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6 beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibited a diurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

Comparison of fetal and maternal heart rate measures using electrocardiographic and cardiotocographic methods.

PubMed

Kisilevsky, Barbara S; Brown, C Ann

2016-02-01

To determine the reliability at term of: (1) two methods of measuring fetal heart rate (HR), electrocardiographic (ECG, the 'gold standard') and cardiotocographic (CTG) and (2) two ECG methods of measuring maternal HR variability over relatively brief periods of time (s-min). During 20 min of rest (N=39) and during 2 min of auditory stimulation (mother's recorded voice, n=19), fetal HR data were collected using an ECG (Monica AN24) and a Hewlett-Packard Model 1351A CTG. Simultaneously, maternal HR data (n=37) were collected using the same ECG device (Monica AN24) and a second stand-alone cardiac monitor (Spacelab 514T cardiac monitor with a QRS detector). During 20 min of maternal rest, correlations of individual fetal CTG with ECG measures of HR at each second were moderate to high (r=.57-.97) for 77% of fetuses. Correlations of HR averaged over fetuses and over each of the 20 min were high (r=.93-.97); fetal HR averaged over 20 min varied between devices from 0.0 to 0.8 bpm. During 2 min of maternal voice presentation, correlations of fetal HR over each second were moderate to high (r=.54-.99) for 95% of fetuses and high (all rs=.99) when averaged across fetuses in 30s or 2 min epochs. Average fetal HR between devices over the 2 min voice varied from 0.0 to 0.6 bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10 min showed 81% of pairs with a difference of ≤ 1 bpm; correlations for HR variability measures varied from r=.89 to .97. Good reliability was demonstrated between individual spontaneous and auditory induced fetal CTG and ECG with high correlations when HR data were averaged over fetuses or in 30-120 s epochs. High reliability of maternal HR measures was obtained using two ECG devices. Copyright © 2016 Elsevier Inc. All rights reserved.

Spectral Detection of Acute Mental Stress with VIS-SWIR Hyperspectral Imagery

DTIC Science & Technology

2013-03-01

collected with a contact probe. The variance of “stress” (red solid lines) is lower on average than “non-stress” (blue dashed lines) because the HRV ...6 ROC Receiver Operating Characteristic . . . . . . . . . . . . . . . . . . . . . 6 HRV Heart Rate Variability...systems. A stressor involving the cognitive system manifests 7 in the form of anxiety , for example, the reaction to a quiz or speech, whereas a

Maturation of Fetal Responses to Music

ERIC Educational Resources Information Center

Kisilevsky, B. S.; Hains, S. M. J.; Jacquet, A.-Y.; Granier-Deferre, C.; Lecanuet, J. P.

2004-01-01

Maturation of fetal response to music was characterized over the last trimester of pregnancy using a 5-minute piano recording of Brahms' Lullaby, played at an average of 95, 100, 105 or 110 dB (A). Within 30 seconds of the onset of the music, the youngest fetuses (28-32 weeks GA) showed a heart rate increase limited to the two highest dB levels;…

Heart rate and physical activity patterns in persons with profound intellectual and multiple disabilities.

PubMed

Waninge, Aly; van der Putten, Annette A J; Stewart, Roy E; Steenbergen, Bert; van Wijck, Ruud; van der Schans, Cees P

2013-11-01

Because physical fitness and health are related to physical activity, it is important to gain an insight into the physical activity levels of persons with profound intellectual and multiple disabilities (PIMD). The purpose of this study was to examine heart rate patterns to measure the activity levels of persons with PIMD and to analyze these heart rate patterns according to participant characteristics, observed level of activity, days, and time of day. The heart rate patterns of 24 participants with PIMD were measured continuously using a heart rate monitor for 8 h · d for a period of 6 days. Physical activity levels were measured with questionnaires. Data were analyzed using multilevel analysis. The results indicate that the participants use only 32% of their heart rate reserve over 6 days. The intensity of heart rate reserve ranged from 1 to 62%. On a given day, wide ranges in heart rates between participants and within persons were observed. Between days, only small ranges in the heart rate were found. The participants could be grouped into 4 classes according to their heart rate. In addition, factors such as time of day, physical activity, and age are significantly related to heart rate patterns. In conclusion, this study is an important first step in exploring activity patterns based on heart rate patterns in persons with PIMD. The participants used relatively small fractions of their heart rate reserves. Time of day and age appear to have a considerable influence on heart rate patterns. The observed classes in heart rate patterns suggest that other probably more personal and psychosocial factors have significant influences on heart rate patterns, as well.

Blade size and weight effects in shovel design.

PubMed

Freivalds, A; Kim, Y J

1990-03-01

The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using five shovels with varying blade sizes and weights to move sand. Energy expenditure, normalised to subject weight and load handled, varied quadratically with the blade-size/shovel-weight (B/W) ratio. Minimum energy cost was at B/W = 0.0676 m2/kg, which for an average subject and average load would require an acceptable 5.16 kcal/min of energy expenditure. Subjects, through the ratings of perceived exertion, also strongly preferred the lighter shovels without regard to blade size. Too large a blade or too heavy a shovel increased energy expenditure beyond acceptable levels, while too small a blade reduced efficiency of the shovelling.

Professional and social activity of patients after heart transplant.

PubMed

Marcinkowska, Urszula; Kukowka, Karol; Gałeczka, Michał; Pudlo, Robert; Zakliczyński, Michał; Zembala, Marian

2015-01-01

The aim of the study is to describe both professional and social activities of patients after heart transplant. Ninety-five heart transplant patients treated at the Silesian Center for Heart Diseases in Zabrze were surveyed, comprising 29 women (30.5%) and 66 men (69.5%). The average age of respondents was 54.3 years old (standard deviation (SD) = 15 years); the average period that had elapsed since the heart transplant was 7.1 years (SD = 4 years). We designed a questionnaire as a tool for collecting information from patients. Twenty-five percent of patients worked at the time of completion of the questionnaire. Eighty percent of those patients were working before and after the transplant, 20%--only after transplantation (p < 0.05). A different job position at a new workplace had 47.8% of patients, 34.8% of them had the same job position at the same work place as they had had before, 63.4% of the heart transplant respondents were pensioners. Eighty-two percent of patients had a certificate with a designated degree of disability--among them: 69% had a certificate for a significant degree of disability, 22%--for a moderate degree of disability. Among those surveyed, 52.5% said that their financial situation had not changed whereas 34.5% of those surveyed reported a change for the worse. Thirty-seven percent of respondents reported changes in family relationships. Seventy-seven percent reported that they received help from family members, as compared with 19% who did not. Only 25.3% of the patients treated at the Silesian Centre for Heart Diseases after heart transplant are employed and it is one of the lowest employment rates in this category of patients in Europe. One third of working patients have the same work place as they had before their operation. Heart transplant is a cause of changes in family relationships. Most often family bonds are strengthened but sometimes family members become nervous, impatient and unwilling to talk about the transplant. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

[Physical workload and maximum acceptable work time among supermarket workers in Cali, Colombia].

PubMed

Ariza, Luz Elena; Idrovo, Alvaro Javier

2005-01-01

In order to guarantee safety and health conditions in labor the maximum physical workload that can be supported by a worker during a labor day, without causing fatigue, must be determined. The objective of this study was to determine the relationship between the physical load, expressed as relative heart rate (RHR), and the maximum acceptable work time (MAWT) in a Colombian working population (n = 30) from a tropical environment. An observational study was carried out during a typical labor day in the warehouses of a supermarket. Physiological, demographic, health and labor conditions data were collected. The resting heart rate level and the average heart rate during work were measured, and the RHR was estimated according to with the model described by Wu & Wang. Significant correlations between MAWT and RHR and other physiological variables were observed. 43% of workers didn't fulfill the MAWT. The only single variable that was associated with fulfillment was a body mass index under 18.5 Kg/m2; the other associated variables were some specific conditions of the occupational environment. Results showed a negative correlation between physiological variables and MAWT. The RHR showed its potential usefulness in the enterprise's occupational health practice. It is important for companies to diminish extended schedules and implement physical conditioning programs.

A new algorithm for segmentation of cardiac quiescent phases and cardiac time intervals using seismocardiography

NASA Astrophysics Data System (ADS)

Jafari Tadi, Mojtaba; Koivisto, Tero; Pänkäälä, Mikko; Paasio, Ari; Knuutila, Timo; Teräs, Mika; Hänninen, Pekka

2015-03-01

Systolic time intervals (STI) have significant diagnostic values for a clinical assessment of the left ventricle in adults. This study was conducted to explore the feasibility of using seismocardiography (SCG) to measure the systolic timings of the cardiac cycle accurately. An algorithm was developed for the automatic localization of the cardiac events (e.g. the opening and closing moments of the aortic and mitral valves). Synchronously acquired SCG and electrocardiography (ECG) enabled an accurate beat to beat estimation of the electromechanical systole (QS2), pre-ejection period (PEP) index and left ventricular ejection time (LVET) index. The performance of the algorithm was evaluated on a healthy test group with no evidence of cardiovascular disease (CVD). STI values were corrected based on Weissler's regression method in order to assess the correlation between the heart rate and STIs. One can see from the results that STIs correlate poorly with the heart rate (HR) on this test group. An algorithm was developed to visualize the quiescent phases of the cardiac cycle. A color map displaying the magnitude of SCG accelerations for multiple heartbeats visualizes the average cardiac motions and thereby helps to identify quiescent phases. High correlation between the heart rate and the duration of the cardiac quiescent phases was observed.

[AUTONOMIC CONTROL OF HEART RATE, BLOOD LACTATE AND ACCELERATION DURING COMBAT SIMULATION IN TAEKWONDO ELITE ATHLETES].

PubMed

Cerda-Kohler, Hugo; Aguayo Fuentealba, Juan Carlos; Francino Barrera, Giovanni; Guajardo-Sandoval, Adrián; Jorquera Aguilera, Carlos; Báez-San Martín, Eduardo

2015-09-01

the aim of the study was to measure the heart rate recovery, blood lactate and movement acceleration during simulated taekwondo competition. twelve male subjects who belong to the national team, with at least five years of experience participated in this research. They performed a simulated combat to evaluate the following variables: (i) Blood lactate after one minute recovery between each round, (ii) Heart rate recovery (HRR) at thirty and sixty seconds in each minute rest between rounds, (iii) Peak acceleration (ACCp) in each round performed. The significance level was set at p < 005. the results showed no significant differences between winners and losers in the HRR at both, thirty and sixty seconds (p > 0.05), blood lactate (p > 0.05), peak acceleration (p > 0.05) and the average acceleration of combat (p = 0.18). There was no correlation between delta lactate and ACCp (r = 0.01; p = 0.93), delta lactate and HRR (r = -0.23; p = 0.18), and ACCp and HRR (r = 0.003; p = 0.98). these data suggest that studied variables would not be decisive in the simulated combat outcomes. Other factors such as technical-tactical or psychological variables could have a significant impact on athletic performance. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Negligible heat strain in armored vehicle officers wearing personal body armor

PubMed Central

2011-01-01

Objectives This study evaluated the heat strain experienced by armored vehicle officers (AVOs) wearing personal body armor (PBA) in a sub-tropical climate. Methods Twelve male AVOs, aged 35-58 years, undertook an eight hour shift while wearing PBA. Heart rate and core temperature were monitored continuously. Urine specific gravity (USG) was measured before and after, and with any urination during the shift. Results Heart rate indicated an intermittent and low-intensity nature of the work. USG revealed six AVOs were dehydrated from pre through post shift, and two others became dehydrated. Core temperature averaged 37.4 ± 0.3°C, with maximum's of 37.7 ± 0.2°C. Conclusions Despite increased age, body mass, and poor hydration practices, and Wet-Bulb Globe Temperatures in excess of 30°C; the intermittent nature and low intensity of the work prevented excessive heat strain from developing. PMID:21801453

Evaluation of decontamination process of heart valve and artery tissues in European Homograft Bank (EHB): a retrospective study of 1,055 cases.

PubMed

Fan, Ye-Dong; Van Hoeck, Beatrice; Holovska, Vanda; Jashari, Ramadan

2012-06-01

To evaluate the efficiency of decontamination practice in European Homograft Bank (EHB), the data of the cardiovascular tissues received during recent 2 years were retrospectively analysed in this study. After initial assessment, the tissues were incubated in a 3-antibiotics' cocktail at 4°C for 20-48 h. The states of contamination were evaluated before and after incubation with the focus on the differences in donor type, tissue type, germ type and incubation time. Amongst 1,055 eligible tissues, 77.2% were hearts and 22.8% were arteries. 82.2% of the tissues were retrieved from the multi-organ donors (MOD), 15.4% from the recipients of heart transplantation (RHT) and 2.4% from the non-heart beating donors (NHBD). The initial contamination rate was 27.4% with a significantly higher incidence in arteries. The RHT tissues had the lowest contamination rate comparing to that of MOD and NHBD. Staphylococcus species was the major source of contamination. After antibiotic incubation, 76.8% of the contaminated tissues were disinfected, which was significantly higher for the hearts than the arteries. The RHT tissues had the highest decontamination rate than that of MOD and NHBD tissues. Propionibacterium acnes was detected in 48.1% of the remaining contaminated cases. The average incubation time of the Propionibacterium-positive tissues was significantly shorter than that of decontaminated tissues. In conclusion, the current decontamination protocol of EHB is sufficient for most of the initially contaminated bacteria, whereas it is inadequate for Propionibacterium acnes. This may be related to the slow-growing nature of this bacterium and thereby the relative shorter antibiotic incubation time.

Heart Rhythm Monitoring in the Constellation Lunar and Launch/Landing EVA Suit: Recommendations from an Expert Panel

NASA Technical Reports Server (NTRS)

Scheuring, Richard A.; Hamilton, D.; Jones, J. A.; Alexander, D.

2008-01-01

Currently there are several physiological monitoring requirements for Extravehicular Activity (EVA) in the Human-Systems Interface Requirements (HSIR) document, including continuous heart rhythm monitoring. However, it is not known whether heart rhythm monitoring in the lunar surface space suit is a necessary capability for lunar surface operations or in launch/landing suit the event of a cabin depressurization enroute to or from the moon. Methods: Current US astronaut corps demographic information was provided to an expert panel of cardiovascular medicine experts, including specialists in electrophysiology, exercise physiology, interventional cardiology and arrhythmia. This information included averages for male/female age, body mass index (BMI), blood pressure, cholesterol, inflammatory markers, echocardiogram, ranges for coronary artery calcium (CAC) scores for long duration astronauts, and ranges for heart rate (HR) and metabolic (MET) rates obtained during microgravity and lunar EVA. Results: The panel determined that no uncontrolled hazard was likely to occur in the suit during lunar surface or contingency microgravity ops that would require ECG monitoring in the highly screened US astronaut population. However having the capability for rhythm monitoring inside the vehicle (IVA) was considered critical to manage an astronaut in distress. Discussion: Heart rate (HR) monitoring alone allows effective monitoring of astronaut health and function. Consequently, electrocardiographic (ECG) monitoring capability as a clinical tool is not essential in the lunar or launch/landing space suit. However, the panel considered that rhythm monitoring could be useful in certain clinical situations, it was not considered required for safe operations. Also, lunar vehicles should be required to have ECG monitoring capability with a minimum of 5-lead ECG (derived 12- lead) for IVA medical assessments.

Usefulness of peak exercise oxygen consumption and the heart failure survival score to predict survival in patients >65 years of age with heart failure.

PubMed

Parikh, Mona N; Lund, Lars H; Goda, Ayumi; Mancini, Donna

2009-04-01

Peak exercise oxygen consumption (Vo(2)) and the Heart Failure (HF) Survival Score (HFSS) were developed in middle-aged patient cohorts referred for heart transplantation with HF. The prognostic value of Vo(2) in patients >65 years has not been well studied. Accordingly, the prognostic value of peak Vo(2) was evaluated in these patients with HF. A retrospective analysis of 396 patients with HF >65 years with cardiopulmonary exercise testing was performed. Peak Vo(2) and components of the HFSS (presence of coronary artery disease, left ventricular ejection fraction, heart rate, mean arterial blood pressure, presence of intraventricular conduction defects, and serum sodium) were collected. Follow-up averaged 1,038 +/- 983 days. Outcome events were defined as death, implantation of a left ventricular assist device, or urgent transplantation. Patients were divided into risk strata for peak Vo(2) and HFSS based on previous cut-off points. Survival curves were derived using Kaplan-Meier analysis and compared using log-rank analysis. Survival differed markedly by Vo(2) stratum (p <0.0001), with significantly better survival rates for the low- (>14 ml/kg/min) versus medium- (10 to 14 ml/kg/min), low- versus high- (<10 ml/kg/min), and medium- versus high-risk strata (all p <0.05). Survival also differed markedly by HFSS stratum (p <0.0001), with significantly better survival rates for the low- (> or =8.10) versus medium- (7.20 to 8.09), low- versus high- (< or =7.19), and medium- versus high-risk strata (all p <0.0001). In conclusion, peak Vo(2) and the HFSS were both excellent parameters to predict survival in patients >65 years with HF.

Regional Variations in the Prevalence of Major Congenital Malformations in Quebec: The Importance of Fetal Growth Environment.

PubMed

Zhao, Jin-Ping; Sheehy, Odile; Bérard, Anick

2015-01-01

Congenital anomalies are the consequence of a complex interaction between genetic predisposition and fetal environment. Based on the Congenital Anomalies Surveillance in Canada Report, between 1998 and 2007 the rate of congenital heart defects in Quebec was significantly higher than the Canadian average; no data on the overall prevalence of congenital anomalies for Quebec or data on regional variations in any province are available. To estimate the prevalence of major congenital malformations (MCMs) in all of the 17 administrative regions of Quebec. Using data from the Quebec Pregnancy Cohort, we included infants if they were born between January 1, 1998 and December 31, 2008. MCMs were identified within the infant's first year of life using validated ICD-9 and ICD-10 codes. The rate of MCMs was calculated and stratified on Quebec's administrative regions. Among 152,353 eligible infants, the prevalence of MCMs was 36.6 (all rates were reported as per 1,000 live births). The regions with the highest rate of MCMs were Lanaudière (48.1), Laval (45.8), and Mauricie (45.1). Regions with the lowest rate were Outaouais (13.4), Côte-Nord (19.1), Abitibi-Témiscamingue (27.5), Gaspésie-îles-de-la-Madeleine (27.9), and Saguenay-Lac-Saint-Jean (28.9). Congenital heart defects (10.3) and musculoskeletal anomalies (12.6) were the most common. Laval had the highest rate of heart defects (16.1), and Lanaudière had the highest rate of musculoskeletal anomalies (22.0). The central regions of Quebec had high rate of MCMs, whereas the relatively genetically homogenous peripheral regions of Quebec had lower rate of MCM, suggesting the importance of fetal growth environment in the etiology of MCMs in Quebec.

Relation of Total and Cardiovascular Death Rates to Climate System, Temperature, Barometric Pressure, and Respiratory Infection.

PubMed

Schwartz, Bryan G; Qualls, Clifford; Kloner, Robert A; Laskey, Warren K

2015-10-15

A distinct seasonal pattern in total and cardiovascular death rates has been reported. The factors contributing to this pattern have not been fully explored. Seven locations (average total population 71,354,000) were selected where data were available including relatively warm, cold, and moderate temperatures. Over the period 2004 to 2009, there were 2,526,123 all-cause deaths, 838,264 circulatory deaths, 255,273 coronary heart disease deaths, and 135,801 ST-elevation myocardial infarction (STEMI) deaths. We used time series and multivariate regression modeling to explore the association between death rates and climatic factors (temperature, dew point, precipitation, barometric pressure), influenza levels, air pollution levels, hours of daylight, and day of week. Average seasonal patterns for all-cause and cardiovascular deaths were very similar across the 7 locations despite differences in climate. After adjusting for multiple covariates and potential confounders, there was a 0.49% increase in all-cause death rate for every 1°C decrease. In general, all-cause, circulatory, coronary heart disease and STEMI death rates increased linearly with decreasing temperatures. The temperature effect varied by location, including temperature's linear slope, cubic fit, positional shift on the temperature axis, and the presence of circulatory death increases in locally hot temperatures. The variable effect of temperature by location suggests that people acclimatize to local temperature cycles. All-cause and circulatory death rates also demonstrated sizable associations with influenza levels, dew point temperature, and barometric pressure. A greater understanding of how climate, temperature, and barometric pressure influence cardiovascular responses would enhance our understanding of circulatory and STEMI deaths. Copyright © 2015 Elsevier Inc. All rights reserved.

Performance of turbo high-pitch dual-source CT for coronary CT angiography: first ex vivo and patient experience.

PubMed

Morsbach, Fabian; Gordic, Sonja; Desbiolles, Lotus; Husarik, Daniela; Frauenfelder, Thomas; Schmidt, Bernhard; Allmendinger, Thomas; Wildermuth, Simon; Alkadhi, Hatem; Leschka, Sebastian

2014-08-01

To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA). First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms). Subjective image quality regarding the presence of motion artefacts was interpreted by two readers on a four-point scale (1, excellent; 4, non-diagnostic). Objective image quality was assessed by calculating distortion vectors. Thereafter, 20 consecutive patients (median, 50 years) undergoing clinically indicated CCTA were included. In the phantom study, image quality was rated diagnostic up to the HR75 bpm, with object distortion being 1 mm or less. Distortion increased above 1 mm at HR of 80-90 bpm. Patients had a mean HR of 66 bpm (47-78 bpm). Coronary segments were of diagnostic image quality for all patients with HR up to 73 bpm. Average effective radiation dose in patients was 0.6 ± 0.3 mSv. Our combined phantom and patient study indicates that CCTA with turbo high-pitch third-generation dual-source 192-slice CT can be performed at HR up to 75 bpm while maintaining diagnostic image quality, being associated with an average radiation dose of 0.6 mSv. • CCTA is feasible with the turbo high-pitch mode. • Turbo high-pitch CCTA provides diagnostic image quality up to 73 bpm. • The radiation dose of high-pitch CCTA is 0.6 mSv on average.

Clinical comparative study on Nitrous Oxide inhalation versus intravenous propofol and Midazolam sedation in Transnasal Gastroscopy.

PubMed

Xiaoqian, Zhou; Tao, Zhang; Bingsong, Luo; Jing, Li; Yu, Deng; Weilan, Zhong

2017-01-01

To investigate the Clinical practice value of nitrous oxide inhalation and intravenous propofol and midazolam sedation in transnasal gastroscopy. From December 2012 to April 2014, two hundred patients receiving painless transnasal gastroscopy on a voluntary basis were selected in Endoscopy center, The First People's Hospital of GuiYang. Patients were divided into two groups: Group-1 consisted of one hundred patients sedated by nitrous oxide inhalation and Group-2 consisted of one hundred patients sedated by intravenous propofol and midazolam. Patients were then examined by transnasal gastroscopy. Patient blood pressure, heart rate, pulse rate and oxygen saturation before, during and after gastroscopy were recorded for both groups. The duration of the gastroscopy and the time of awakening were also recorded. After examination, the patients were asked to assess the level of discomfort experiences during the gastroscopy procedure. All patients successfully underwent the transnasal gastroscopy. There were 57 males and 43 females in the nitrous oxide inhalation group with an average age of 43.11±8.27 years. The average duration of examination and time of awaking in the nitrous oxide inhalation group was of 152.7±9.80 secs and 50±7.89 secs respectively. For the intravenous propofol and midazolam sedation group, there were 53 males and 47 females with an average age of 41.26±7.98 years. The average duration of examination and time of awaking in the intravenous propofol and midazolam sedation group was of 149.07±10.25 seconds and 390±20.89 # seconds respectively. The two groups showed no significant difference in the duration of examination. There was no difference in the age or sex. The former had a less significant impact on heart rate, oxygen saturation and blood pressure, while the intravenous propofol and midazolam sedation decreased blood pressure dramatically and this effect persisted after examination. Nitrous oxide inhalation has higher safety and tolerance with a brighter application prospect for transnasal gastroscopy.

The effect of decibel level of music stimuli and gender on head circumference and physiological responses of premature infants in the NICU.

PubMed

Cassidy, Jane W

2009-01-01

The purpose of this study was to examine different protocols with regard to the presentation of music stimuli and compare gender differential reactions to those stimuli. Subjects for this study (N = 63) were premature infants in the Neonatal Intensive Care Unit (NICU) between the gestational ages of 28 and 33 weeks. Half of the experimental infants listened to 20 mins of lullaby music (female voice with orchestral background) on 2 days followed by 20 mins of classical music (Mozart string music) on 2 days. The other half listened to the same music in the reverse order. One quarter of the males and one quarter of the females listened to music presented at an average of 65 dB, one quarter at an average of 70 dB, one quarter at an average of 75 dB, and one quarter did not listen to any music and served as control subjects. Head circumference data were collected four times by the researcher: (a) upon receipt of parental consent, (b) on the first day of music presentation (1 week after consent), (c) on the last day of music presentation, and (d) 1 week after music presentation. Physiological data (heart rate, respiratory rate, oxygen saturation) were recorded by the researcher at 2-minute intervals starting 4 minutes prior to and ending 4 minutes after music presentation. There was a significant difference (p < .0001) in average daily head growth across time, but this seems unrelated to the music condition as the same curvilinear trend (larger gain during days of treatment, smaller gain during baseline before and after treatment) was noted for control infants who did not listen to music. Results indicate a significant (p = .002), but biologically unimportant, decrease in heart rate over the course of data collection. No differences due to gender were noted.

Influence of ECG sampling rate in fetal heart rate variability analysis.

PubMed

De Jonckheere, J; Garabedian, C; Charlier, P; Champion, C; Servan-Schreiber, E; Storme, L; Debarge, V; Jeanne, M; Logier, R

2017-07-01

Fetal hypoxia results in a fetal blood acidosis (pH<;7.10). In such a situation, the fetus develops several adaptation mechanisms regulated by the autonomic nervous system. Many studies demonstrated significant changes in heart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).

Seismocardiography-Based Cardiac Computed Tomography Gating Using Patient-Specific Template Identification and Detection

PubMed Central

Yao, Jingting; Tridandapani, Srini; Wick, Carson A.

2017-01-01

To more accurately trigger cardiac computed tomography angiography (CTA) than electrocardiography (ECG) alone, a sub-system is proposed as an intermediate step toward fusing ECG with seismocardiography (SCG). Accurate prediction of quiescent phases is crucial to prospectively gating CTA, which is susceptible to cardiac motion and, thus, can affect the diagnostic quality of images. The key innovation of this sub-system is that it identifies the SCG waveform corresponding to heart sounds and determines their phases within the cardiac cycles. Furthermore, this relationship is modeled as a linear function with respect to heart rate. For this paper, B-mode echocardiography is used as the gold standard for identifying the quiescent phases. We analyzed synchronous ECG, SCG, and echocardiography data acquired from seven healthy subjects (mean age: 31; age range: 22–48; males: 4) and 11 cardiac patients (mean age: 56; age range: 31–78; males: 6). On average, the proposed algorithm was able to successfully identify 79% of the SCG waveforms in systole and 68% in diastole. The simulated results show that SCG-based prediction produced less average phase error than that of ECG. It was found that the accuracy of ECG-based gating is more susceptible to increases in heart rate variability, while SCG-based gating is susceptible to high cycle to cycle variability in morphology. This pilot work of prediction using SCG waveforms enriches the framework of a comprehensive system with multiple modalities that could potentially, in real time, improve the image quality of CTA. PMID:28845370

Oxygen limitation and tissue metabolic potential of the African fish Barbus neumayeri: roles of native habitat and acclimatization

PubMed Central

2011-01-01

Background Oxygen availability in aquatic habitats is a major environmental factor influencing the ecology, behaviour, and physiology of fishes. This study evaluates the contribution of source population and hypoxic acclimatization of the African fish, Barbus neumayeri, in determining growth and tissue metabolic enzyme activities. Individuals were collected from two sites differing dramatically in concentration of dissolved oxygen (DO), Rwembaita Swamp (annual average DO 1.35 mgO2 L-1) and Inlet Stream West (annual average DO 5.58 mgO2 L-1) in Kibale National Park, Uganda, and reciprocally transplanted using a cage experiment in the field, allowing us to maintain individuals under natural conditions of oxygen, food availability, and flow. Fish were maintained under these conditions for four weeks and sampled for growth rate and the activities of phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS), and cytochrome c oxidase (CCO) in four tissues, liver, heart, brain, and skeletal muscle. Results Acclimatization to the low DO site resulted in lower growth rates, lower activities of the aerobic enzyme CCO in heart, and higher activities of the glycolytic enzyme PFK in heart and skeletal muscle. The activity of LDH in liver tissue was correlated with site of origin, being higher in fish collected from a hypoxic habitat, regardless of acclimatization treatment. Conclusions Our results suggest that the influence of site of origin and hypoxic acclimatization in determining enzyme activity differs among enzymes and tissues, but both factors contribute to higher glycolytic capacity and lower aerobic capacity in B. neumayeri under naturally-occurring conditions of oxygen limitation. PMID:21251277

Oxygen limitation and tissue metabolic potential of the African fish Barbus neumayeri: roles of native habitat and acclimatization.

PubMed

Martínez, Mery L; Raynard, Erin L; Rees, Bernard B; Chapman, Lauren J

2011-01-20

Oxygen availability in aquatic habitats is a major environmental factor influencing the ecology, behaviour, and physiology of fishes. This study evaluates the contribution of source population and hypoxic acclimatization of the African fish, Barbus neumayeri, in determining growth and tissue metabolic enzyme activities. Individuals were collected from two sites differing dramatically in concentration of dissolved oxygen (DO), Rwembaita Swamp (annual average DO 1.35 mgO2 L(-1)) and Inlet Stream West (annual average DO 5.58 mgO2 L(-1)) in Kibale National Park, Uganda, and reciprocally transplanted using a cage experiment in the field, allowing us to maintain individuals under natural conditions of oxygen, food availability, and flow. Fish were maintained under these conditions for four weeks and sampled for growth rate and the activities of phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS), and cytochrome c oxidase (CCO) in four tissues, liver, heart, brain, and skeletal muscle. Acclimatization to the low DO site resulted in lower growth rates, lower activities of the aerobic enzyme CCO in heart, and higher activities of the glycolytic enzyme PFK in heart and skeletal muscle. The activity of LDH in liver tissue was correlated with site of origin, being higher in fish collected from a hypoxic habitat, regardless of acclimatization treatment. Our results suggest that the influence of site of origin and hypoxic acclimatization in determining enzyme activity differs among enzymes and tissues, but both factors contribute to higher glycolytic capacity and lower aerobic capacity in B. neumayeri under naturally-occurring conditions of oxygen limitation.

Effect of metoprolol administration on renal sodium handling in experimental congestive heart failure.

PubMed

DiBona, G F; Sawin, L L

1999-07-06

Long-term metoprolol therapy improves cardiac performance and decreases mortality in patients with chronic congestive heart failure (CHF). This study examined the effect of long-term metoprolol therapy on renal sodium handling in an experimental rat model of CHF. Rats with left coronary ligation and myocardial infarction-induced CHF were treated with metoprolol (1.5 mg. kg-1. h-1) or vehicle for 3 weeks by osmotic minipump. They were then evaluated for their ability to excrete a short-term sodium load (5% body weight isotonic saline infusion over 30 minutes) and a long-term sodium load (change from low- to high-sodium diet over 8 days). All CHF rats had left ventricular end-diastolic pressure >10 mm Hg, and heart weight/body weight ratios averaged 0.68+/-0.02% (versus control of approximately 0.40%). Compared with vehicle CHF rats (n=19), metoprolol CHF rats (n=18) had lower basal values of mean arterial pressure (122+/-3 versus 112+/-3 mm Hg) and heart rate (373+/-14 versus 315+/-9 bpm) and decreased heart rate responses to intravenous doses of isoproterenol. During short-term isotonic saline volume loading, metoprolol CHF rats excreted 54+/-4% more of the sodium load than vehicle CHF rats. During long-term dietary sodium loading, metoprolol CHF rats retained 28+/-3% less sodium than vehicle CHF rats. Metoprolol treatment of rats with CHF results in an improved ability to excrete both short- and long-term sodium loads.

Optimizing Estimates of Instantaneous Heart Rate from Pulse Wave Signals with the Synchrosqueezing Transform.

PubMed

Wu, Hau-Tieng; Lewis, Gregory F; Davila, Maria I; Daubechies, Ingrid; Porges, Stephen W

2016-10-17

With recent advances in sensor and computer technologies, the ability to monitor peripheral pulse activity is no longer limited to the laboratory and clinic. Now inexpensive sensors, which interface with smartphones or other computer-based devices, are expanding into the consumer market. When appropriate algorithms are applied, these new technologies enable ambulatory monitoring of dynamic physiological responses outside the clinic in a variety of applications including monitoring fatigue, health, workload, fitness, and rehabilitation. Several of these applications rely upon measures derived from peripheral pulse waves measured via contact or non-contact photoplethysmography (PPG). As technologies move from contact to non-contact PPG, there are new challenges. The technology necessary to estimate average heart rate over a few seconds from a noncontact PPG is available. However, a technology to precisely measure instantaneous heat rate (IHR) from non-contact sensors, on a beat-to-beat basis, is more challenging. The objective of this paper is to develop an algorithm with the ability to accurately monitor IHR from peripheral pulse waves, which provides an opportunity to measure the neural regulation of the heart from the beat-to-beat heart rate pattern (i.e., heart rate variability). The adaptive harmonic model is applied to model the contact or non-contact PPG signals, and a new methodology, the Synchrosqueezing Transform (SST), is applied to extract IHR. The body sway rhythm inherited in the non-contact PPG signal is modeled and handled by the notion of wave-shape function. The SST optimizes the extraction of IHR from the PPG signals and the technique functions well even during periods of poor signal to noise. We contrast the contact and non-contact indices of PPG derived heart rate with a criterion electrocardiogram (ECG). ECG and PPG signals were monitored in 21 healthy subjects performing tasks with different physical demands. The root mean square error of IHR estimated by SST is significantly better than commonly applied methods such as autoregressive (AR) method. In the walking situation, while AR method fails, SST still provides a reasonably good result. The SST processed PPG data provided an accurate estimate of the ECG derived IHR and consistently performed better than commonly applied methods such as autoregressive method.

Lessons from the Heart: Individualizing Physical Education with Heart Rate Monitors.

ERIC Educational Resources Information Center

Kirkpatrick, Beth; Birnbaum, Burton H.

Learning about the relationship between heart rate and physical activity is an important aspect of fitness education. Use of a heart rate monitor (HRM) helps a student to understand how stretching and large muscle movements gradually increase the heart rate and blood flow, and enables students to measure their exercise heart rates and set goals…

Association of the consumption of common food groups and beverages with mortality from cancer, ischaemic heart disease and diabetes mellitus in Serbia, 1991-2010: an ecological study.

PubMed

Ilic, Milena; Ilic, Irena; Stojanovic, Goran; Zivanovic-Macuzic, Ivana

2016-01-05

This paper reports association between mortality rates from cancer, ischaemic heart disease and diabetes mellitus and the consumption of common food groups and beverages in Serbia. In this ecological study, data on both mortality and the average annual consumption of common food groups and beverages per household's member were obtained from official data-collection sources. The multivariate linear regression analysis was used to determine the strength of the associations between consumption of common food groups and beverages and mortality rates. Markedly increasing trends of cancer, ischaemic heart disease and diabetes mellitus mortality rates were observed in Serbia in the period 1991-2010. Mortality rates from cancer were negatively associated with consumption of vegetable oil (p=0.005) and grains (p=0.001), and same was found for ischaemic heart disease (p=0.002 and 0.021, respectively), while consumption of other dairy products showed a significant positive association (p<0.001 and p=0.032, respectively). In men and women, mortality rates from diabetes mellitus showed a significant positive association with consumption of poultry (p=0.014 and 0.004, respectively). Consumption of beef and grains showed a significant negative association with cancer mortality rates in both genders (p=0.002 and p<0.001 in men, and p<0.001 and p=0.014 in women, respectively), while consumption of cheese was negatively associated only in men (p<0.001). Mortality from diabetes mellitus showed a significant positive association with consumption of animal fat and other dairy products only in women (p=0.003 and 0.046, respectively). Association between unfavourable mortality trends from cancer, ischaemic heart disease and diabetes mellitus, and common food groups and beverages consumption was observed and should be assessed in future analytical epidemiological studies. Promotion of healthy diet is sorely needed in Serbia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Heart rate monitoring mobile applications.

PubMed

Chaudhry, Beenish M

2016-01-01

Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone's camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, 'Unique Heart Rate Monitor', you can also maintain your heart rate history for personal reflection and sharing with a provider.

Nicotine delivery, retention, and pharmacokinetics from various electronic cigarettes

PubMed Central

St. Helen, Gideon; Havel, Christopher; Dempsey, Delia; Jacob, Peyton; Benowitz, Neal L.

2015-01-01

Aims To measure the systemic retention of nicotine, propylene glycol (PG), and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. Design E-cigarette users recruited over the Internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several time after use. Setting San Francisco, California, USA. Participants Thirteen healthy, experienced adult e-cigarette users (6 females and 7 males). Measurements Plasma nicotine was analyzed by GC-MS/MS, and nicotine, VG, and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. Findings E-cigarettes delivered an average of 1.3 (0.9–1.8) mg (mean and 95% CI) of nicotine and 94% of the inhaled dose, 1.2 (0.8–1.7), was systemically retained. Average maximum plasma nicotine concentration (Cmax) was 8.4 (5.4–11.5) ng/mL and time of maximal concentration (Tmax) was 2 to 5 minutes; one participant had Tmax of 30 minutes. 89% and 92% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 bpm after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. Conclusions E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarettes users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. PMID:26430813

Oxygen uptake during mini trampoline exercise in normal-weight, endurance-trained adults and in overweight-obese, inactive adults: A proof-of-concept study.

PubMed

Höchsmann, Christoph; Rossmeissl, Anja; Baumann, Sandra; Infanger, Denis; Schmidt-Trucksäss, Arno

2018-03-15

To examine cardiorespiratory exertion during mini trampoline exercises of different intensities in both endurance-trained athletes and overweight-obese adults. Physically healthy participants (Group A: normal-weight, endurance-trained athletes; Group B: inactive, overweight-obese adults) participated in two measurement appointments and three training sessions in between appointments, in which participants familiarized themselves with the use of the mini trampoline and the execution of the exercises. The primary outcome was the ⩒O 2peak for each of the six mini trampoline exercises relative to the ⩒O 2peak as established during an all-out exercise test on a bike ergometer during the first measurement appointment. Secondary outcomes were average ⩒O 2 as well as maximum and average heart rate. The six mini trampoline exercises generated ⩒O 2peak values between 42% and 81% in the endurance-trained athletes and between 58% and 87% in the overweight-obese participants, both in relation to the bike ergometer ⩒O 2peak . Average ⩒O 2 values ranged from 35% to 69% (endurance-trained athletes) and from 48% to 71% (overweight-obese participants), depending on exercise. Average heart rate likewise lay in a range that can be categorized as moderate-to-vigorous aerobic exercise for both groups. A moderate-to-strong correlation (0.658 to 0.875, depending on exercise) between bike ergometer ⩒O 2peak and mini trampoline ⩒O 2peak was found for all six exercises. Mini trampoline exercise has the potential to produce training intensities that concur with established exercise guidelines. The exercise intensity is self-adjusting and allows for an effective and safe workout for different users with a wide range of fitness levels.

Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations.

PubMed

Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios

2015-01-01

It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. © 2015 S. Karger AG, Basel.

Taking Care of Your Heart

MedlinePlus

... risk for a heart attack. A is for A1C The A1C test tells you your average blood glucose over ... blood glucose may be reported in 2 ways: ■ A1C (as a percentage) ■ estimated Average Glucose (eAG) in ...

Review and Analysis of Existing Mobile Phone Apps to Support Heart Failure Symptom Monitoring and Self-Care Management Using the Mobile Application Rating Scale (MARS).

PubMed

Masterson Creber, Ruth M; Maurer, Mathew S; Reading, Meghan; Hiraldo, Grenny; Hickey, Kathleen T; Iribarren, Sarah

2016-06-14

Heart failure is the most common cause of hospital readmissions among Medicare beneficiaries and these hospitalizations are often driven by exacerbations in common heart failure symptoms. Patient collaboration with health care providers and decision making is a core component of increasing symptom monitoring and decreasing hospital use. Mobile phone apps offer a potentially cost-effective solution for symptom monitoring and self-care management at the point of need. The purpose of this review of commercially available apps was to identify and assess the functionalities of patient-facing mobile health apps targeted toward supporting heart failure symptom monitoring and self-care management. We searched 3 Web-based mobile app stores using multiple terms and combinations (eg, "heart failure," "cardiology," "heart failure and self-management"). Apps meeting inclusion criteria were evaluated using the Mobile Application Rating Scale (MARS), IMS Institute for Healthcare Informatics functionality scores, and Heart Failure Society of America (HFSA) guidelines for nonpharmacologic management. Apps were downloaded and assessed independently by 2-4 reviewers, interclass correlations between reviewers were calculated, and consensus was met by discussion. Of 3636 potentially relevant apps searched, 34 met inclusion criteria. Most apps were excluded because they were unrelated to heart failure, not in English or Spanish, or were games. Interrater reliability between reviewers was high. AskMD app had the highest average MARS total (4.9/5). More than half of the apps (23/34, 68%) had acceptable MARS scores (>3.0). Heart Failure Health Storylines (4.6) and AskMD (4.5) had the highest scores for behavior change. Factoring MARS, functionality, and HFSA guideline scores, the highest performing apps included Heart Failure Health Storylines, Symple, ContinuousCare Health App, WebMD, and AskMD. Peer-reviewed publications were identified for only 3 of the 34 apps. This review suggests that few apps meet prespecified criteria for quality, content, or functionality, highlighting the need for further refinement and mapping to evidence-based guidelines and room for overall quality improvement in heart failure symptom monitoring and self-care related apps.

Ambulatory heart rate of professional taxi drivers while driving without their typical psychosocial work stressors: a pilot study.

PubMed

Choi, BongKyoo; Choi, SangJun; Jeong, JeeYeon; Lee, JiWon; Shu, Shi; Yu, Nu; Ko, SangBaek; Zhu, Yifang

2016-01-01

Few studies have examined ambulatory cardiovascular physiological parameters of taxi drivers while driving in relation to their occupational hazards. This study aims to investigate and quantify the impact of worksite physical hazards as a whole on ambulatory heart rate of professional taxi drivers while driving without their typical worksite psychosocial stressors. Ambulatory heart rate (HR driving ) of 13 non-smoking male taxi drivers (24 to 67 years old) while driving was continuously assessed on their 6-hour experimental on-road driving in Los Angeles. Percent maximum HR range (PMHR driving ) of the drivers while driving was estimated based on the individual HR driving values and US adult population resting HR (HR rest ) reference data. For analyses, the HR driving and PMHR driving data were split and averaged into 5-min segments. Five physical hazards inside taxi cabs were also monitored while driving. Work stress and work hours on typical work days were self-reported. The means of the ambulatory 5-min HR driving and PMHR driving values of the 13 drivers were 80.5 bpm (11.2 bpm higher than their mean HR rest ) and 10.7 % (range, 5.7 to 19.9 %), respectively. The means were lower than the upper limits of ambulatory HR and PMHR for a sustainable 8-hour work (35 bpm above HR rest and 30 % PMHR), although 15-27 % of the 5-min HR driving and PMHR driving values of one driver were higher than the limits. The levels of the five physical hazards among the drivers were modest: temperature (26.4 ± 3.0 °C), relative humidity (40.7 ± 10.4 %), PM 2.5 (21.5 ± 7.9  μg /m 3 ), CO 2 (1,267.1 ± 580.0 ppm) and noise (69.7 ± 3.0 dBA). The drivers worked, on average, 72 h per week and more than half of them reported that their job were often stressful. The impact of physical worksite hazards alone on ambulatory HR of professional taxi drivers in Los Angeles generally appeared to be minor. Future ambulatory heart rate studies including both physical and psychosocial hazards of professional taxi drivers are warranted.

A prospective comparative study of interaction between lithium and modified electroconvulsive therapy.

PubMed

Thirthalli, Jagadisha; Harish, Thippeswamy; Gangadhar, Bangalore N

2011-03-01

To compare patients on lithium and those not on lithium with regard to adverse effects while receiving ECT. Inpatients with schizophrenia, non-organic psychosis, mania and depression, who were prescribed ECTs either on (n=27) or not (n=28) on lithium were studied. Clinicians blind to lithium-status recorded seizure parameters, interaction with succinyl choline, cardiovascular response, recovery from ECT and immediate post-ECT complications. The lithium group showed no significant difference in terms of seizure variables, apnea time, and recovery from anaesthesia when compared to the non-lithium group. Average maximum heart rate, average maximum systolic blood pressure and average maximum rate pressure product were significantly lower in patients who had combined lithium and ECT. In lithium patients the average time to post-ECT recovery was directly correlated with serum lithium level. Though concurrent lithium is by and large safe during ECT, it benefits to maintain serum lithium level at lower end of therapeutic range. However, the findings can be applied to relatively young patients with no risk factors for ECT-complications.

Resting Heart Rate and Outcomes in Patients with Cardiovascular Disease: Where Do We Currently Stand?

PubMed Central

Menown, Ian BA; Davies, Simon; Gupta, Sandeep; Kalra, Paul R; Lang, Chim C; Morley, Chris; Padmanabhan, Sandosh

2013-01-01

Background Data from large epidemiological studies suggest that elevated heart rate is independently associated with cardiovascular and all-cause mortality in patients with hypertension and in those with established cardiovascular disease. Clinical trial findings also suggest that the favorable effects of beta-blockers and other heart rate–lowering agents in patients with acute myocardial infarction and congestive heart failure may be, at least in part, due to their heart rate–lowering effects. Contemporary clinical outcome prediction models such as the Global Registry of Acute Coronary Events (GRACE) score include admission heart rate as an independent risk factor. Aims This article critically reviews the key epidemiology concerning heart rate and cardiovascular risk, potential mechanisms through which an elevated resting heart rate may be disadvantageous and evaluates clinical trial outcomes associated with pharmacological reduction in resting heart rate. Conclusions Prospective randomised data from patients with significant coronary heart disease or heart failure suggest that intervention to reduce heart rate in those with a resting heart rate >70 bpm may reduce cardiovascular risk. Given the established observational data and randomised trial evidence, it now appears appropriate to include reduction of elevated resting heart rate by lifestyle +/− pharmacological therapy as part of a secondary prevention strategy in patients with cardiovascular disease. PMID:22954325

Simultaneous monitoring of maternal and fetal heart rate variability during labor in relation with fetal gender.

PubMed

Gonçalves, Hernâni; Fernandes, Diana; Pinto, Paula; Ayres-de-Campos, Diogo; Bernardes, João

2017-11-01

Male gender is considered a risk factor for several adverse perinatal outcomes. Fetal gender effect on fetal heart rate (FHR) has been subject of several studies with contradictory results. The importance of maternal heart rate (MHR) monitoring during labor has also been investigated, but less is known about the effect of fetal gender on MHR. The aim of this study is to simultaneously assess maternal and FHR variability during labor in relation with fetal gender. Simultaneous MHR and FHR recordings were obtained from 44 singleton term pregnancies during the last 2 hr of labor (H 1, H 2 ). Heart rate tracings were analyzed using linear (time- and frequency-domain) and nonlinear indices. Both linear and nonlinear components were considered in assessing FHR and MHR interaction, including cross-sample entropy (cross-SampEn). Mothers carrying male fetuses (n = 22) had significantly higher values for linear indices related with MHR average and variability and sympatho-vagal balance, while the opposite occurred in the high-frequency component and most nonlinear indices. Significant differences in FHR were only observed in H 1 with higher entropy values in female fetuses. Assessing the differences between FHR and MHR, statistically significant differences were obtained in most nonlinear indices between genders. A significantly higher cross-SampEn was observed in mothers carrying female fetuses (n = 22), denoting lower synchrony or similarity between MHR and FHR. The variability of MHR and the synchrony/similarity between MHR and FHR vary with respect to fetal gender during labor. These findings suggest that fetal gender needs to be taken into account when simultaneously monitoring MHR and FHR. © 2017 Wiley Periodicals, Inc.

Effect of beta-blocker therapy on heart rate response in patients with hypertension and newly diagnosed untreated obstructive sleep apnea syndrome.

PubMed

Wolf, Jacek; Drozdowski, Jacek; Czechowicz, Krzysztof; Winklewski, Paweł J; Jassem, Ewa; Kara, Tomas; Somers, Virend K; Narkiewicz, Krzysztof

2016-01-01

Beta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA. We studied 88 hypertensive patients (56 on BBs and 32 BB naive) with newly-diagnosed moderate-to-severe OSA who were free of major pulmonary comorbidities and did not require antiarrhythmic therapy. ECGs recorded during sleep were investigated for heart rate (HR) responses to apneas allowing to compare extreme HR accelerations and decelerations between the groups. Average sleep-time HR was comparable in BB-naive (BB-) and BB-treated (BB+) patients. Direct comparisons showed that HR decelerations were also similar in the two subgroups (53.8±9.6 vs. 54.4±7.8 bpm; P=0.78, for BB- and BB+, respectively) however, BBs blunted the OSA-induced HR accelerations (82.3±12.2 vs. 74.3±10.0; P=0.003). After adjusting for baseline HR and magnitude of desaturations, HR decelerations were more evident in BB-naive group whereas tachycardic responses remained blunted in the BB+ group. The incidence of ectopies and conduction abnormalities were comparable across two groups. Beta-blockers do not potentiate apnea-induced HR decelerations, attenuate apnea-induced increases in heart rate and do not influence incidence of ectopies and conduction abnormalities in patients with hypertension and moderate-to-severe, untreated OSA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Association Between Leisure Time Physical Activity, Cardiopulmonary Fitness, Cardiovascular Risk Factors, and Cardiovascular Workload at Work in Firefighters.

PubMed

Yu, Clare C W; Au, Chun T; Lee, Frank Y F; So, Raymond C H; Wong, John P S; Mak, Gary Y K; Chien, Eric P; McManus, Alison M

2015-09-01

Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios. Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

Comparison of energy expenditure and heart rate responses between three commercial group fitness classes.

PubMed

Wickham, James B; Mullen, Nicholas J; Whyte, Douglas G; Cannon, Jack

2017-07-01

The objectives of this study were to compare the energy expenditure and heart rate responses between three commercial group fitness classes (group resistance exercise [PUMP]; indoor stationary cycling [RIDE]; and step aerobics [STEP]). One-Way Repeated Measures incorporating a Latin Square Design for class randomisation. Ten participants (5 males and 5 females) completed each group fitness class in random order with energy expenditure and heart rate determined using an Actiheart monitor. STEP and RIDE produced significantly (p<0.05) higher average heart rates (HR avg ) (85.8±5.1% and 86.4±4.3% of HR max , respectively) compared to PUMP (73.7±7% of HR max ). HR peak was also significantly (p<0.05) higher in STEP and RIDE (97.1±4.7% and 95.6±4.5% of HR max, respectively) when compared with the PUMP class (90±5.9% of HR max ). Total energy expenditure (TEE), both absolute and relative, were significantly (p<0.05) higher for STEP (2101.7±560.2kJ and 0.59±0.07kJkg -1 min -1 ) and RIDE (1880.4±420kJ and 0.58±0.03kJkg -1 min -1 ) when compared with the PUMP class (1385.1±504kJ and 0.36±0.07kJkg -1 min -1 ). These data suggest that overall exercise intensity and energy expenditure was highly comparable between RIDE and STEP, which suggests these group fitness classes are more effective for developing cardiovascular fitness and assisting with weight management compared with group resistance exercise classes when performed on a regular basis. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effects of yoga in patients with paroxysmal atrial fibrillation - a randomized controlled study.

PubMed

Wahlstrom, Maria; Rydell Karlsson, Monica; Medin, Jörgen; Frykman, Viveka

2017-01-01

Patients with atrial fibrillation often have an impaired quality of life (QoL). Practising yoga may decrease stress and have positive effects on mental and physical health. The aim of this study was to investigate whether yoga can improve QoL and decrease blood pressure and heart rate in patients with paroxysmal atrial fibrillation (PAF). In this pilot study, 80 patients diagnosed with PAF were randomized to standard treatment (control group, n=40) or standard treatment in combination with yoga (yoga group, n=40) during a 12-week period. QoL, blood pressure and heart rate were evaluated at baseline and at the end of the study (12 (+2) weeks). EuroQoL-5D (EQ-5D) Visual Analogue Scale (VAS) and the two dimensions in Short-Form Health Survey (SF-36) were used to evaluate QoL. At baseline there was a significant difference in QoL between the groups in EQ-5D VAS- scale ( p=0.02) and SF-36 mental health score ( p<0.001) in which the control group had higher scores. At the end of the study, the yoga group averaged higher SF-36 mental health scores. There was a significant difference between the two groups ( p=0.016), but no differences in EQ-5D VAS- scale and physiological health score was seen between the two groups. At the end of the study, the yoga group had significantly lower heart rate ( p=0.024) and systolic ( p=0.033) and diastolic blood pressure ( p<0.001) compared to the control group. Yoga with light movements and deep breathing may lead to improved QoL, lower blood pressure and lower heart rate in patients with PAF compared to a control group. Yoga could be a complementary treatment method to standard therapy.

[Improving physiological and psychological status in a hemodialysis patient: a nursing experience using an exercise training program].

PubMed

Liu, Yueh-Min; Yeh, Mei-Ling; Chung, Yu-Chu

2013-10-01

Exercise training during hemodialysis has been found to improve functional capacity, nutritional status, cardiovascular risk factors, depression, and well being in hemodialysis patients. This report describes a nursing experience that applied exercise training to improve activity intolerance, powerlessness, and ineffective health maintenance in a hemodialysis patient. The care period was from May 11 to July 27, 2012. The author collected information using observation, interview, physical examination, and medical record review and identified patient care problems including activity intolerance, powerlessness, and ineffective health maintenance. In addition to providing individual nursing interventions, the author designed a stationary bicycle installed at the end of the bed. The patient was asked use the bicycle to exercise 30 mins per time, three times per week for a period of 12 weeks during the patient's hemodialysis period. Before and after a 12-week of exercise training, collected the 6-minute walk test (6MWT), self-perceived improvement, and self-reported depression scales were performed prior to and after completion of the intervention. Hematological triglyceride, albumin, and hemoglobin data were collected each week. Heart rate, blood pressure, and oxygen saturation were examined prior to and after the intervention to ensure patient safety. After the 12-week intervention, the average heart rate achieved 40-60% of the maximum heart rate and the heart rate peaked between 85 and 121 bpm. Moreover, the 6MWT distance increased from 210 m to 255 m, triglyceride decreased from 622 mg/dL to 173 mg/dL, and self-perceived fatigue and depression markedly improved. This nursing experience is shared with nurses caring for patients with similar conditions.

[Patients' characteristics and clinical management of atrial fibrillation in primary healthcare in Spain: FIATE Study].

PubMed

Lobos-Bejarano, José María; del Castillo-Rodríguez, José Carlos; Mena-González, Amparo; Alemán-Sánchez, José J; Cabrera de León, Antonio; Barón-Esquivias, Gonzalo; Pastor-Fuentes, Agustín

2013-10-05

The main therapeutic objective in atrial fibrillation (AF) patients is stroke prevention. This study is aimed to determine whether the anticoagulant therapy may be appropriate regarding to the Guidelines and patients' profile in primary healthcare in Spain. A national, multicenter, cross-sectional study of AF patients attended in primary healthcare in Spain has been conducted. The study involved 185 family physicians whose patients were randomized. A total of 3,759 AF patients were randomized from the clinical records, and 2,070 were included in the study, at an average age of 74 (11) years old (50.7% female). Most of them (78%) had permanent AF and high comorbidity rates (hypertension 75%, obesity 30%, diabetes 27%, heart failure 20%, coronary heart disease 17%, and social risk 15%). Patients diagnosed in primary healthcare were more frequently asymptomatic than in hospital setting (36%; P<.001). The therapeutic strategy was based on the heart rate control in 4 out of 5 patients. Anticoagulation therapy was widely used (84%), more frequently in patients with permanent vs. non-permanent AF (91 vs. 60%, P<.001). Follow-up and monitoring was mainly performed in primary care (72%). The anticoagulation control was suboptimal, with a 66% of the international normalized ratio (INR) in therapeutic range, dropping to 33% when the last 3 available INR were included (P<.001). A high rate of patients with anticoagulant therapy in primary healthcare has been found in this research. INR control, however, remains suboptimal. Heart rate control is the most commonly used strategy. The decision about the anticoagulation should be based on the thromboembolic risk rather than in the arrhytmia type. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Reversible immobilization of free-ranging snow leopards (panthera uncia) with a combination of medetomidine and tiletamine-zolazepam.

PubMed

Johansson, Örjan; Malmsten, Jonas; Mishra, Charudutt; Lkhagvajav, Purevjav; McCarthy, Tom

2013-04-01

Conservation and research of the elusive snow leopard (Panthera uncia) have been hampered by inadequate knowledge about its basic life history. Global positioning system (GPS) collars can provide useful information, but there has been limited information available on safe capture methods, drug doses, and efficacy for effective immobilization of free-ranging snow leopards. We describe a drug protocol using a combination of medetomidine and tiletamine-zolazepam for the chemical immobilization of free-ranging snow leopards. We also describe physiologic responses to immobilization drugs, including rectal temperature, heart rate, respiratory rate, and relative hemoglobin oxygen saturation (SpO2) recorded every 10 min. Our study was carried out in the Tost Mountains adjacent to the Great Gobi Desert, in southern Mongolia, between August 2008 and April 2012. Eighteen snow leopards were captured or recaptured with foot-snares on 42 occasions and anesthetized for marking with GPS collars. The snow leopards received on average (±SD) 0.020±0.04 mg/kg body mass medetomidine and 2.17±0.45 mg/kg tiletamine-zolazepam. The duration of ensuing anesthesia was 69±13 min, including an induction period of 10 (±4) min. Anesthesia was reversed with 4 mg (0.10±0.04 mg/kg) atipamezole administered intramuscularly. The mean value for SpO2 for the 37 captures where we could record physiologic values was 91±4. The SpO2 increased significantly during anesthesia (+0.06±0.02%/min), whereas rectal temperature (average 38.1±0.7 C/min, change -0.04±0.003 C/min), heart rate (average 97±9 beats/min, change -0.20±0.03 beats/min), and respiratory rate (average 26±6 breaths/min, change -0.11±0.03 breaths/min) decreased significantly. A dose of 80 mg tiletamine-zolazepam (2 mg/kg body weight) and 0.72 mg medetomidine (0.02 mg/kg body weight) safely immobilized all adult and subadult snow leopards (weight 25-45 kg) in our study. All measured physiologic values remained within clinically acceptable limits.

Sustained Progress: New Findings about the Effectiveness and Operation of Small Public High Schools of Choice in New York City

ERIC Educational Resources Information Center

Bloom, Howard S.; Unterman, Rebecca

2013-01-01

In 2002, New York City embarked on an ambitious and wide-ranging series of education reforms. At the heart of its high school reforms were three interrelated changes: the institution of a district wide high school choice process for all rising ninth-graders, the closure of 31 large, failing high schools with an average graduation rate of 40…

The mitochondrial uniporter controls fight or flight heart rate increases.

PubMed

Wu, Yuejin; Rasmussen, Tyler P; Koval, Olha M; Joiner, Mei-Ling A; Hall, Duane D; Chen, Biyi; Luczak, Elizabeth D; Wang, Qiongling; Rokita, Adam G; Wehrens, Xander H T; Song, Long-Sheng; Anderson, Mark E

2015-01-20

Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate.

Heart rate never lies: interventional cardiologist and Braude's quote revised

PubMed Central

Cook, Stéphane; Stauffer, Jean-Christophe; Goy, Jean-Jacques; Graf, Denis; Puricel, Serban; Frobert, Aurélien; Muller, Olivier; Togni, Mario; Arroyo, Diego

2016-01-01

Background Interventional cardiologists may be immune to stress, allowing them to perform complex percutaneous interventions under pressure. Objectives To assess heart rate (HR) variations as a surrogate marker of stress of interventional cardiologists during percutaneous cardiac procedures and in every-day life. Design This is a single-centre observational study including a total of six male interventional cardiologists performing coronary interventions and pacemaker implantations. Participants were asked to record their HR with the Apple Watch Device during procedures, every-day life and control activities such as outpatient consultations, sport, marital conflicts and sexual intercourse. Results Average daily HR was 88±17 bpm. During work days, HR increased significantly during procedures (90±17 bpm) compared with days outside the cathlab (87±17 bpm, p=0.02). The average HR was higher during a regular week working (88±16 bpm) compared with weekends off (84±18 bpm, p=0.002). Complex cardiac procedures were associated with higher HR up to 122 bpm. Peak HR were higher during physical exertion. Of note, participants complained of hypersexuality and mania after night shifts. Conclusions Work and especially percutaneous cardiac procedures increase HR independently of physical exertion suggesting that interventional cardiologists experience mental stress and emotions. PMID:26835145

Heart rate never lies: interventional cardiologist and Braude's quote revised.

PubMed

Cook, Stéphane; Stauffer, Jean-Christophe; Goy, Jean-Jacques; Graf, Denis; Puricel, Serban; Frobert, Aurélien; Muller, Olivier; Togni, Mario; Arroyo, Diego

2016-01-01

Interventional cardiologists may be immune to stress, allowing them to perform complex percutaneous interventions under pressure. To assess heart rate (HR) variations as a surrogate marker of stress of interventional cardiologists during percutaneous cardiac procedures and in every-day life. This is a single-centre observational study including a total of six male interventional cardiologists performing coronary interventions and pacemaker implantations. Participants were asked to record their HR with the Apple Watch Device during procedures, every-day life and control activities such as outpatient consultations, sport, marital conflicts and sexual intercourse. Average daily HR was 88±17 bpm. During work days, HR increased significantly during procedures (90±17 bpm) compared with days outside the cathlab (87±17 bpm, p=0.02). The average HR was higher during a regular week working (88±16 bpm) compared with weekends off (84±18 bpm, p=0.002). Complex cardiac procedures were associated with higher HR up to 122 bpm. Peak HR were higher during physical exertion. Of note, participants complained of hypersexuality and mania after night shifts. Work and especially percutaneous cardiac procedures increase HR independently of physical exertion suggesting that interventional cardiologists experience mental stress and emotions.

When an Increase in Central Systolic Pressure Overrides the Benefits of Heart Rate Lowering.

PubMed

Messerli, Franz H; Rimoldi, Stefano F; Bangalore, Sripal; Bavishi, Chirag; Laurent, Stephane

2016-08-16

An elevated resting heart rate has been unequivocally linked to adverse cardiovascular events. Conversely, a physiologically low heart rate may confer longevity benefits. Moreover, pharmacological heart rate lowering reduces cardiovascular outcomes in patients with heart failure, with the magnitude of the reduction associated with survival benefit. In contrast, pharmacological heart rate lowering paradoxically increases cardiovascular events in hypertension, possibly because it elicits a ventricular-vascular mismatch, leading to increased central systolic blood pressure (BP). By the same hemodynamic mechanism, pharmacological heart rate lowering also engenders an increase in central (aortic) BP in coronary heart disease and, as a consequence, fails to decrease myocardial oxygen consumption. Whether in heart failure, hypertension, or coronary heart disease, or even athletes, heart rate lowering consistently increases central systolic pressure. The increase in central systolic BP is prone to abolish the potential benefits of heart rate lowering interventions, possibly accounting for failure to reduce outcomes in patients with hypertension and coronary artery disease. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Heart rate monitoring mobile applications

PubMed Central

2016-01-01

Total number of times a heart beats in a minute is known as the heart rate. Traditionally, heart rate was measured using clunky gadgets but these days it can be measured with a smartphone’s camera. This can help you measure your heart rate anywhere and at anytime, especially during workouts so you can adjust your workout intensity to achieve maximum health benefits. With simple and easy to use mobile app, ‘Unique Heart Rate Monitor’, you can also maintain your heart rate history for personal reflection and sharing with a provider. PMID:28293594

Pharmacological heart rate lowering in patients with a preserved ejection fraction-review of a failing concept.

PubMed

Meyer, Markus; Rambod, Mehdi; LeWinter, Martin

2018-07-01

Epidemiological studies have demonstrated that high resting heart rates are associated with increased mortality. Clinical studies in patients with heart failure and reduced ejection fraction have shown that heart rate lowering with beta-blockers and ivabradine improves survival. It is therefore often assumed that heart rate lowering is beneficial in other patients as well. Here, we critically appraise the effects of pharmacological heart rate lowering in patients with both normal and reduced ejection fraction with an emphasis on the effects of pharmacological heart rate lowering in hypertension and heart failure. Emerging evidence from recent clinical trials and meta-analyses suggest that pharmacological heart rate lowering is not beneficial in patients with a normal or preserved ejection fraction. This has just begun to be reflected in some but not all guideline recommendations. The detrimental effects of pharmacological heart rate lowering are due to an increase in central blood pressures, higher left ventricular systolic and diastolic pressures, and increased ventricular wall stress. Therefore, we propose that heart rate lowering per se reproduces the hemodynamic effects of diastolic dysfunction and imposes an increased arterial load on the left ventricle, which combine to increase the risk of heart failure and atrial fibrillation. Pharmacologic heart rate lowering is clearly beneficial in patients with a dilated cardiomyopathy but not in patients with normal chamber dimensions and normal systolic function. These conflicting effects can be explained based on a model that considers the hemodynamic and ventricular structural effects of heart rate changes.

Comorbidity, hospitalization, and medication use and their influence on mental and motor development of young infants with Down syndrome.

PubMed

van Trotsenburg, A S Paul; Heymans, Hugo S A; Tijssen, Jan G P; de Vijlder, Jan J M; Vulsma, Thomas

2006-10-01

Young infants with Down syndrome have an increased occurrence of several well-known medical conditions such as congenital heart and gastrointestinal disease. The aim of this study was to establish consequences like hospitalization and medication use rates and to determine their possible influence on early neurodevelopment. This study compared 2 years of thyroxine treatment with placebo in 196 neonates with Down syndrome who were included in a previously reported randomized clinical trial. Parents were interviewed about comorbidity, hospitalization, and medication use at random assignment and regularly thereafter. Data were cross-checked with discharge letters when available. The influence of comorbidity on neurodevelopment at 2 years old (Bayley Scales of Infant Development II) was determined by stepwise multiple linear-regression analysis. Before trial entry, 163 infants with Down syndrome had been admitted to hospital for an average of 14.01 days, whereas during the trial, 95 of 181 infants who completed the trial were hospitalized for an average 19.75 days. Main hospitalization reasons during the trial were lung/airway and congenital heart and gastrointestinal disease. The 48 infants operated on for heart or gastrointestinal disease accounted for 1401 of the total number of 1876 hospital admission days during the trial and for 33 of 62 admissions for lung/airway infection. During their second year of life, approximately 60% of the infants were prescribed drugs, mostly antibiotics and pulmonary. Regression analysis showed infantile spasms, "other" central nervous system disease, and gastrointestinal disease necessitating surgery to be associated with greater developmental age delays at 24 months old (mental: 6.87, 3.52, and 1.69 months; and motor: 3.59, 2.54, and 1.68 months, respectively). Hospital admission and medication use rates in young infants with Down syndrome are still very high, mainly because of congenital heart and gastrointestinal disease and acquired respiratory disease. Central nervous system disease and gastrointestinal disease necessitating surgery were independently associated with a worse developmental outcome.

Sarcocystis arieticanis (Apicomplexa: Sarcocystidae) infecting the heart muscles of the domestic sheep, Ovis aries (Artiodactyla: Bovidae), from K. S. A. on the basis of light and electron microscopic data.

PubMed

Al Quraishy, Saleh; Morsy, Kareem; Bashtar, Abdel-Rahman; Ghaffar, Fathy Abdel; Mehlhorn, Heinz

2014-10-01

In the present study, the heteroxenous life cycle of Sarcocystis species from three strains of the slaughtered sheep at Al-Azizia and Al-Saada abattoirs in Riyadh city, K.S.A., was studied. Muscle samples of the oesophagus, diaphragm, tongue, skeletal and heart muscles were examined. Varied natural infection rates in the muscles of the examined sheep strains were recorded as 83% in Niemy, 81.5% in Najdy and 90% in Sawakny sheep. Muscles of the diaphragm showed the highest infection level above all organs except Najdy sheep in which oesophagus has the highest rate. Also, the heart was the lowest infected organ (40% Niemy, 44% Najdy and 53% Sawakny). Microscopic sarcocysts of Sarcocystis arieticanis are easily identified in sections through the heart muscles of the domestic sheep Ovis aries (Artiodactyla: Bovidae). Cysts measured 38.5-64.4 μm (averaged 42.66 μm) in width and 62.4-173.6 μm (averaged 82.14 μm) in length. The validity of this species was confirmed by means of ultrastructural characteristics of the primary cyst wall (0.1-0.27 μm thick) which revealed the presence of irregularly shaped crowded and hairy-like projections underlined by a thin layer of ground substance. This layer consisted mainly of fine, dense homogenous granules enclosing the developing metrocytes and merozoites that usually contain nearly all the structures of the apical complex and fill the interior cavity of the cyst. Several septa derived from the ground substance divided the cyst into compartments. The merozoites were banana-shaped and measured 12-16 μm in length with centrally or posteriorly located nuclei. Experimental infection of carnivores by feeding heavily infected sheep muscles revealed that the dog, Canis familiaris, is the only final host of the present Sarcocystis species. Gamogony, sporogonic stages and characteristics of sporulated oocysts were also investigated.

Profile of Heart Donors from the Human Valve Bank of the Santa Casa de Misericórdia de Curitiba

PubMed Central

Ferreira, Renata Maria; da Costa, Marise Teresinha Brenner Affonso; Canciglieri Junior, Osiris; Sant'Anna, Ângelo Márcio Oliveira

2016-01-01

Introduction Human heart valves are used as replacement valves and have satisfactory functional results compared with conventional prostheses. Objective Characterize the profile of effective heart donors from the human valve bank of the santa casa de misericórdia de curitiba and analyze the association between the profile variables. Methods It consists of a retrospective and quantitative study of electronic medical records from heart donors for heart valves. every heart donation made to the bank between january 2004 and december 2014 was studied. Results 2,149 donations were analyzed, from donors aged 0 to 71 years old, with an average of 34.9 ± 15.03 years old. most donors were male 65.7% (n=1,411) and 34.3% (n=738) were female. among the most frequent causes of the donors' death are trauma at 53% (n=1,139) and cerebral vascular accident at 34.2% (n=735). there was significant statistical association between the analyzed variables. Conclusion There has been an improvement in brazil's donation rate, being essential that the tissue banks work together with the state and federal district centers for notification, procurement and distribution of organs in order to increase the number of donors. PMID:27556322

Changes in Heart Rate Associated with Exenatide Once Weekly: Pooled Analysis of Clinical Data in Patients with Type 2 Diabetes.

PubMed

Marso, Steven P; Hardy, Elise; Han, Jenny; Wang, Hui; Chilton, Robert J

2018-04-01

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycemia in patients with type 2 diabetes, but heart rate increases have been observed. A pooled post hoc analysis of 11 randomized clinical trials (N = 4595) of 10-30 weeks' duration from the exenatide once-weekly (QW) development program evaluated heart rate with exenatide QW (intervention group) and exenatide twice daily (BID), liraglutide, and non-GLP-1RAs (insulin, metformin, pioglitazone, and sitagliptin) (comparison groups). The time course and size of heart rate changes from baseline and the relationship of heart rate change with baseline heart rate were studied. A multivariate analysis (9 studies; N = 3903) examined associations between patient characteristics or treatments and heart rate increases. Mean baseline heart rate ± standard deviation was 75.0 ± 8.5 beats per minute (bpm) with exenatide QW (n = 2096), 75.8 ± 8.7 bpm with exenatide BID (n = 606), 75.2 ± 8.9 bpm with liraglutide (n = 450), and 74.5 ± 8.6 bpm with non-GLP-1RAs (n = 1443). Least-squares mean ± standard error changes from baseline to final heart rate were + 2.7 ± 0.2, + 1.0 ± 0.3, and + 3.0 ± 0.4 bpm with exenatide QW, exenatide BID, and liraglutide, respectively, and - 0.8 ± 0.2 bpm with non-GLP-1RAs. The size and direction of heart rate changes in individual patients varied within each treatment group at all time points. At posttreatment follow-up, heart rate reverted to the baseline level after GLP-1RA discontinuation. Heart rate changes correlated negatively with baseline heart rate for all therapies (r = - 0.3 to - 0.4). Baseline heart rate was the strongest predictor of increased heart rate. Small increases in heart rate were associated with exenatide QW, exenatide BID, and liraglutide treatments but reverted to baseline after discontinuation. Increases were more likely in patients with a low baseline heart rate. The clinical relevance of these heart rate increases is unknown but will be clarified by several ongoing and recently completed cardiovascular outcome studies.

Heart activity monitoring using 3D hologram based on smartphone.

PubMed

Thap, Tharoeun; Heewon Chung; Jinseok Lee

2016-08-01

In this paper, we used smartphone to obtained pulsatile signal from a fingertip by illuminating the skin tissue using flashlight and with an on-board camera to record the change of the light intensity reflected from the tissue. The pulsatile signal is produced by analyzing average green component values of the frames taken by the camera and the heart rate is estimated in real time by detecting the pulse peaks. Based on each instant obtained heartbeat, we design a heart animation that beats according to each interval of the heartbeat. At the same time, we made a simple pyramid shaped hologram from a transparent OHP film to show the heart animation acting above the smartphone screen in three-dimensional view. With this application, users can actually monitor their heart activity in 3D rather than just to see the pulsatile signal graphically. The performances were done in two different conditions: under bright and dark environments. The holograms were made based on three different materials: grey transparent film, clear transparent film, and hard black acrylic board; the grey transparent film provided better performance and we achieved satisfactory results regardless of all environments.

A mobile system for assessment of physiological response to posture transitions.

PubMed

Jovanov, Emil; Milosevic, Mladen; Milenković, Aleksandar

2013-01-01

Posture changes initiate a dynamic physiological response that can be used as an indicator of the overall health status. We introduce an inconspicuous mobile wellness monitoring system (imWell) that continuously assesses the dynamic physiological response to posture transitions during activities of daily living. imWell utilizes a Zephyr BioHarness 3 physiological monitor that continually reports heart activity and physical activity via Bluetooth to a personal device (e.g. smartphone). The personal device processes the reported activity data in real-time to recognize posture transitions from the accelerometer data and to characterize dynamic heart response to posture changes. It annotates, logs, and uploads the heart activity data to our mHealth server. In this paper we present algorithms for detection of posture transitions and heart activity characterization during a sit-to-stand transition. The proposed system was tested on seven healthy subjects performing a predefined protocol. The total average and standard deviation for sit-to-stand transition time is 2.7 ± 0.69 s, resulting in the change of heart rate of 27.36 ± 9.30 bpm (from 63.3 ± 9.02 bpm to 90.66 ± 10.09 bpm).

Reduced intrinsic heart rate is associated with reduced arrhythmic susceptibility in guinea-pig heart.

PubMed

Osadchii, Oleg E

2014-12-01

In the clinical setting, patients with slower resting heart rate are less prone to cardiovascular death compared with those with elevated heart rate. However, electrophysiological adaptations associated with reduced cardiac rhythm have not been thoroughly explored. In this study, relationships between intrinsic heart rate and arrhythmic susceptibility were examined by assessments of action potential duration (APD) rate adaptation and inducibility of repolarization alternans in sinoatrial node (SAN)-driven and atrioventricular (AV)-blocked guinea-pig hearts perfused with Langendorff apparatus. Electrocardiograms, epicardial monophasic action potentials, and effective refractory periods (ERP) were assessed in normokalemic and hypokalemic conditions. Slower basal heart rate in AV-blocked hearts was associated with prolonged ventricular repolarization during spontaneous beating, and with attenuated APD shortening at increased cardiac activation rates during dynamic pacing, when compared with SAN-driven hearts. During hypokalemic perfusion, the inducibility of repolarization alternans and tachyarrhythmia by rapid pacing was found to be lower in AV-blocked hearts. This difference was ascribed to prolonged ERP in the setting of reduced basal heart rate, which prevented ventricular capture at critically short pacing intervals required to induce arrhythmia. Reduced basal heart rate is associated with electrophysiological changes that prevent electrical instability upon an abrupt cardiac acceleration.

Effects of acute hypoxia on the determination of anaerobic threshold using the heart rate-work rate relationships during incremental exercise tests.

PubMed

Ozcelik, O; Kelestimur, H

2004-01-01

Anaerobic threshold which describes the onset of systematic increase in blood lactate concentration is a widely used concept in clinical and sports medicine. A deflection point between heart rate-work rate has been introduced to determine the anaerobic threshold non-invasively. However, some researchers have consistently reported a heart rate deflection at higher work rates, while others have not. The present study was designed to investigate whether the heart rate deflection point accurately predicts the anaerobic threshold under the condition of acute hypoxia. Eight untrained males performed two incremental exercise tests using an electromagnetically braked cycle ergometer: one breathing room air and one breathing 12 % O2. The anaerobic threshold was estimated using the V-slope method and determined from the increase in blood lactate and the decrease in standard bicarbonate concentration. This threshold was also estimated by in the heart rate-work rate relationship. Not all subjects exhibited a heart rate deflection. Only two subjects in the control and four subjects in the hypoxia groups showed a heart rate deflection. Additionally, the heart rate deflection point overestimated the anaerobic threshold. In conclusion, the heart rate deflection point was not an accurate predictor of anaerobic threshold and acute hypoxia did not systematically affect the heart rate-work rate relationships.

When heart goes “BOOM” to fast. Heart rate greater than 80 as mortality predictor in acute myocardial infarction

PubMed Central

Davidovic, Goran; Iric-Cupic, Violeta; Milanov, Srdjan; Dimitijevic, Aleksandra; Petrovic-Janicijevic, Mirjana

2013-01-01

Many prospective studies established association between high heart rate and increased cardiovascular morbidity and mortality, independently of other risk factors. Heart rate over 80 beats per minute more often leads to atherosclerotic plaque disruption, the main step in developing acute coronary syndrome. Purpose was to investigate the incidence of higher heart rate levels in patients with anterior wall acute myocardial infarction with ST-segment elevation and the influence of heart rate on mortality. Research included 140 patients with anterior wall acute myocardial infarction with ST-segment elevation treated in Coronary Unit, Clinical Center Kragujevac in the period from January 2001-June 2006. Heart rate was calculated as the mean value of baseline and heart rate in the first 30 minutes after admission. Other risk factors were also followed to determine their connection with elevated heart rate. Results showed that the majority of patients survived (over 70%). In a total number of patients, more than 75% had a heart rate levels greater than 80 beats per minute. There was a significant difference in heart rate on addmision between survivors and patients who died, with a greater levels in patients with fatal outcome. Both, univariate and multivariate regression analysis singled out heart rate greater than 80 beats per minute as independent mortality predictor in these patients. Heart rate greater than 80 beats per minute is a major, independent risk factor for morbidity and important predictor of mortality in patients with acute myocardial infarction. PMID:23991346

The Effect of Compression Stockings on Physiological and Psychological Responses after 5-km Performance in Recreationally Active Females.

PubMed

Treseler, Christine; Bixby, Walter R; Nepocatych, Svetlana

2016-07-01

Treseler, C, Bixby, WR, and Nepocatych, S. The effect of compression stockings on physiological and psychological responses after 5-Km performance in recreationally active females. J Strength Cond Res 30(7): 1985-1991, 2016-The purpose of the study was to examine the physiological and perceptual responses to wearing below-the-knee compression stockings (CS) after a 5-km running performance in recreationally active women. Nineteen women were recruited to participate in the study (20 ± 1 year, 61.4 ± 5.3 kg, 22.6 ± 3.9% body fat). Each participant completed two 5-km performance time trials with CS or regular socks in a counterbalanced order separated by 1 week. For each session, 5-km time, heart rate (HR), rate of perceived exertion (RPE), pain pressure threshold, muscle soreness (MS), and rate of perceived recovery were measured. There was no significant difference in average 5-km times between CS and regular socks (p = 0.74) and HR response (p = 0.42). However, significantly higher RPE and lower gain scores (%) for lower extremity MS but not for calf were observed with CS when compared with regular socks (p = 0.05, p = 0.01, and p = 0.3, respectively). Based on the results of this study, there were no significant improvements in average 5-km running time, heart rate, or perceived calf MS. However, participants perceived less MS in lower extremities and working harder with CS compared with regular socks. Compression stockings may not cause significant physiological improvements; however, there might be psychological benefits positively affecting postexercise recovery.

Systematic off-pump coronary artery revascularization in multivessel disease: experience of three hundred cases.

PubMed

Cartier, R; Brann, S; Dagenais, F; Martineau, R; Couturier, A

2000-02-01

We sought to report our recent experience with off-pump coronary artery revascularization in multivessel disease. Between October 1996 and December 1998, 300 off-pump beating heart operations were performed at the Montreal Heart Institute by a single surgeon, representing 94% of all procedures undertaken during this same time frame (97% for 1998). This cohort of patients was compared with 1870 patients operated on with cardiopulmonary bypass from 1995 to 1996. Mean age, sex distribution, and preoperative risk factors were comparable for the two groups. On average, 2.92 +/- 0.8 and 2.84 +/- 0.6 grafts per patient were completed in the beating heart and cardiopulmonary bypass groups, respectively. A majority of patients (70%) had either a triple or quadruple bypass. Coronary anastomoses were achieved with myocardial mechanical stabilization and heart "verticalization." Ischemic time was shorter in the beating heart group (29.8 +/- 0.9 vs 45 +/- 0.4 minutes, P <.05). Similarly, the need for transfusion was significantly less in the beating heart group (beating heart operations, 34%; cardiopulmonary bypass, 66%; P <.005). Reduced use of postoperative intra-aortic counterpulsation, as well as a lower rise in creatine kinase MB isoenzyme, was observed in the beating heart group. Operative mortality rates (beating heart operations, 1. 3%; cardiopulmonary bypass, 2%) and perioperative myocardial infarction (beating heart operations, 3.6%; cardiopulmonary bypass, 4.2%) were comparable for the two groups. In a majority of patients, off-pump complete coronary artery revascularization is an acceptable alternative to conventional operations, yielding good results given progressive experience, rigorous technique, and adequate coronary artery stabilization.

The Impact of Early Life Stress on Growth and Cardiovascular Risk: A Possible Example for Autonomic Imprinting?

PubMed

Buchhorn, Reiner; Meint, Sebastian; Willaschek, Christian

2016-01-01

Early life stress is imprinting regulatory properties with life-long consequences. We investigated heart rate variability in a group of small children with height below the third percentile, who experienced an episode of early life stress due to heart failure or intra uterine growth retardation. These children appear to develop autonomic dysfunction in later life. Compared to the healthy control group heart rate variability (HRV) is reduced on average in a group of 101 children with short stature. Low HRV correlates to groups of children born small for gestational age (SGA), children with cardiac growth failure and children with congenital syndromes, but not to those with constitutional growth delay (CGD), who had normal HRV. Reduced HRV indicated by lower RMSSD and High Frequency (HF)-Power is indicating reduced vagal activity as a sign of autonomic imbalance. It is not short stature itself, but rather the underlying diseases that are the cause for reduced HRV in children with height below the third percentile. These high risk children-allocated in the groups with an adverse autonomic imprinting in utero or infancy (SGA, congenital heart disease and congenital syndromes)-have the highest risk for 'stress diseases' such as cardiovascular disease in later life. The incidence of attention deficit disorder is remarkably high in our group of short children.

The Impact of Early Life Stress on Growth and Cardiovascular Risk: A Possible Example for Autonomic Imprinting?

PubMed Central

Buchhorn, Reiner; Meint, Sebastian

2016-01-01

Introduction Early life stress is imprinting regulatory properties with life-long consequences. We investigated heart rate variability in a group of small children with height below the third percentile, who experienced an episode of early life stress due to heart failure or intra uterine growth retardation. These children appear to develop autonomic dysfunction in later life. Results Compared to the healthy control group heart rate variability (HRV) is reduced on average in a group of 101 children with short stature. Low HRV correlates to groups of children born small for gestational age (SGA), children with cardiac growth failure and children with congenital syndromes, but not to those with constitutional growth delay (CGD), who had normal HRV. Reduced HRV indicated by lower RMSSD and High Frequency (HF)-Power is indicating reduced vagal activity as a sign of autonomic imbalance. Conclusion It is not short stature itself, but rather the underlying diseases that are the cause for reduced HRV in children with height below the third percentile. These high risk children—allocated in the groups with an adverse autonomic imprinting in utero or infancy (SGA, congenital heart disease and congenital syndromes)—have the highest risk for ‘stress diseases’ such as cardiovascular disease in later life. The incidence of attention deficit disorder is remarkably high in our group of short children. PMID:27861527

Fiber optic sensor based on reflectivity configurations to detect heart rate

NASA Astrophysics Data System (ADS)

Yunianto, M.; Marzuki, A.; Riyatun, R.; Lestari, D.

2016-11-01

Research of optical fiber-based heart rate detection sensor has been conducted using the reflection configurationon the thorax motion modified. Optical fiber used in this research was Plastic Optical Fiber (POF) with a diameter of 0.5. Optical fiber system is made with two pieces of fiber, the first fiber is to serve as a transmitter transmitting light from the source to the reflector membrane, the second fiber serves as a receiver. One of the endsfrom the two fibersis pressed and positioned perpendicular of reflector membrane which is placed on the surface of the chest. The sensor works on the principle of intensity changes captured by the receiver fiber when the reflector membrane gets the vibe from the heart. The light source used is in the form of Light Emitting Diode (LED) and Light Dependent Resistor (LDR) as a light sensor. Variations are performed on the reflector membrane diameter. The light intensity received by the detector increases along with the increasing width of the reflector membrane diameter. The results show that this sensor can detect the harmonic peak at a frequency of 1.5 Hz; 7.5 Hz; 10.5 Hz; and 22.5 Hz in a healthy human heart with an average value of Beat Per Minute (BPM) by 78 times, a prototype sensor that is made can work and function properly.

Deep-Diving California Sea Lions: Are They Pushing Their Physiological Limit

DTIC Science & Technology

2015-09-30

resting heart rate (70 bpm ) (Ponganis et al. 1997) is reached, and e) duration of and heart rate during the ascent tachycardia. If possible, heart rate...Resting heart rates were 54 + 6 beats min-1 ( bpm ), and in dives of 1-3 min, 3-5 min, and > 5 min, dive heart rates (number of beats/dive duration...were 55 + 8, 51 + 6, and 40 + bpm . As illustrated in Figs. 1 and 2, the heart rate profile was characterized by rapid development of a bradycardia

Activation of N-methyl-d-aspartate receptors reduces heart rate variability and facilitates atrial fibrillation in rats.

PubMed

Shi, Shaobo; Liu, Tao; Wang, Dandan; Zhang, Yan; Liang, Jinjun; Yang, Bo; Hu, Dan

2017-07-01

The goal of this study was to assess the effects of N-methyl-d-aspartate (NMDA) receptors activation on heart rate variability (HRV) and susceptibility to atrial fibrillation (AF). Rats were randomized for treatment with saline, NMDA (agonist of NMDA receptors), or NMDA plus MK-801 (antagonist of NMDA receptors) for 2 weeks. Heart rate variability was evaluated by using implantable electrocardiogram telemeters. Atrial fibrillation susceptibility was assessed with programmed stimulation in isolated hearts. Compared with the controls, the NMDA-treated rats displayed a decrease in the standard deviation of normal RR intervals, the standard deviation of the average RR intervals, the mean of the 5-min standard deviations of RR intervals, the root mean square of successive differences, and high frequency (HF); and an increase in low frequency (LF) and LF/HF (all P< 0.01). Additionally, the NMDA-treated rats showed prolonged activation latency and reduced effective refractory period (all P< 0.01). Importantly, AF was induced in all NMDA-treated rats. While atrial fibrosis developed, connexin40 downgraded and metalloproteinase 9 upgraded in the NMDA-treated rats (all P< 0.01). Most of the above alterations were mitigated by co-administering with MK-801. These results indicate that NMDA receptors activation reduces HRV and enhances AF inducibility, with cardiac autonomic imbalance, atrial fibrosis, and degradation of gap junction protein identified as potential mechanistic contributors. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Cardiac and Vascular Function in Bedrested Volunteers: Effects of Artificial Gravity Training

NASA Technical Reports Server (NTRS)

Meng, M.; Platts, S.; Stenger, M.; Diedrich, A.; Schlegel, T.; Natapoff, A.; Knapp, C.; Evans, J.

2007-01-01

Cardiovascular effects of an artificial gravity (AG) countermeasure on deconditioned male volunteers were studied. In two groups of men we measured cardiovascular parameters at rest and in response to 30 minutes of 80 deg. head up tilt (HUT) before, at the end of, and four days following 21 days of 6 deg. head down bed rest (HDBR). One group (N=7) underwent no countermeasure while the other (N=8) received a daily, one hour, dose (2.5 gz at the foot, decreasing to 1.0 gz at the heart) of AG training on the Johnson Space Center short radius centrifuge. Cardiovascular parameters measured included heart rate, blood pressure, stroke volume, cardiac output, peripheral vascular resistance, plasma volume shifts, and vasoactive hormones. Untrained subjects exhibited shorter tilt survival (on average 8 minutes shorter) compared to trained subjects. By the end of bed rest, mean heart rate (MHR) was elevated in both groups (both supine and during tilt). In addition, treated subjects demonstrated lower, tilt-induced, increases in MHR four days following HDBR, indicating a more rapid return to pre bed rest conditions. Results from an index of autonomic balance (percentage of MHR spectral power in the respiratory frequency range) in control of heart rate are consistent with the interpretation that parasympathetic nervous system withdrawal was responsible for both tilt- and bed rest-induced increases in MHR. Our data support our pre-study hypothesis that AG treatment would lessen cardiovascular effects of deconditioning in bed rested men and suggest that AG should be further pursued as a space flight countermeasure.

A study of the 200-metre fast walk test as a possible new assessment tool to predict maximal heart rate and define target heart rate for exercise training of coronary heart disease patients.

PubMed

Casillas, Jean-Marie; Joussain, Charles; Gremeaux, Vincent; Hannequin, Armelle; Rapin, Amandine; Laurent, Yves; Benaïm, Charles

2015-02-01

To develop a new predictive model of maximal heart rate based on two walking tests at different speeds (comfortable and brisk walking) as an alternative to a cardiopulmonary exercise test during cardiac rehabilitation. Evaluation of a clinical assessment tool. A Cardiac Rehabilitation Department in France. A total of 148 patients (133 men), mean age of 59 ±9 years, at the end of an outpatient cardiac rehabilitation programme. Patients successively performed a 6-minute walk test, a 200 m fast-walk test (200mFWT), and a cardiopulmonary exercise test, with measure of heart rate at the end of each test. An all-possible regression procedure was used to determine the best predictive regression models of maximal heart rate. The best model was compared with the Fox equation in term of predictive error of maximal heart rate using the paired t-test. Results of the two walking tests correlated significantly with maximal heart rate determined during the cardiopulmonary exercise test, whereas anthropometric parameters and resting heart rate did not. The simplified predictive model with the most acceptable mean error was: maximal heart rate = 130 - 0.6 × age + 0.3 × HR200mFWT (R(2) = 0.24). This model was superior to the Fox formula (R(2) = 0.138). The relationship between training target heart rate calculated from measured reserve heart rate and that established using this predictive model was statistically significant (r = 0.528, p < 10(-6)). A formula combining heart rate measured during a safe simple fast walk test and age is more efficient than an equation only including age to predict maximal heart rate and training target heart rate. © The Author(s) 2014.

Long‐term Cardiovascular Risks Associated With an Elevated Heart Rate: The Framingham Heart Study

PubMed Central

Ho, Jennifer E.; Larson, Martin G.; Ghorbani, Anahita; Cheng, Susan; Coglianese, Erin E.; Vasan, Ramachandran S.; Wang, Thomas J.

2014-01-01

Background Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow‐up. Methods and Results Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, P<0.0001). Higher heart rate was also associated with higher all‐cause (HR 1.17, 95% CI 1.11 to 1.24, P<0.0001) and cardiovascular mortality (HR 1.18, 95% CI 1.04 to 1.33, P=0.01). Spline analyses did not suggest a lower threshold beyond which the benefit of a lower heart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001). Conclusions Individuals with a higher heart rate are at elevated long‐term risk for cardiovascular events, in particular, heart failure, and all‐cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation. PMID:24811610

Physiological thermoregulation in a crustacean? Heart rate hysteresis in the freshwater crayfish Cherax destructor.

PubMed

Goudkamp, Jacqueline E; Seebacher, Frank; Ahern, Mark; Franklin, Craig E

2004-07-01

Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degrees C) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans.

G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish

PubMed Central

Romano, Shannon N.; Edwards, Hailey E.; Ryan, Kevin J.

2017-01-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels. PMID:29065151

G protein-coupled estrogen receptor regulates embryonic heart rate in zebrafish.

PubMed

Romano, Shannon N; Edwards, Hailey E; Souder, Jaclyn Paige; Ryan, Kevin J; Cui, Xiangqin; Gorelick, Daniel A

2017-10-01

Estrogens act by binding to estrogen receptors alpha and beta (ERα, ERβ), ligand-dependent transcription factors that play crucial roles in sex differentiation, tumor growth and cardiovascular physiology. Estrogens also activate the G protein-coupled estrogen receptor (GPER), however the function of GPER in vivo is less well understood. Here we find that GPER is required for normal heart rate in zebrafish embryos. Acute exposure to estrogens increased heart rate in wildtype and in ERα and ERβ mutant embryos but not in GPER mutants. GPER mutant embryos exhibited reduced basal heart rate, while heart rate was normal in ERα and ERβ mutants. We detected gper transcript in discrete regions of the brain and pituitary but not in the heart, suggesting that GPER acts centrally to regulate heart rate. In the pituitary, we observed gper expression in cells that regulate levels of thyroid hormone triiodothyronine (T3), a hormone known to increase heart rate. Compared to wild type, GPER mutants had reduced levels of T3 and estrogens, suggesting pituitary abnormalities. Exposure to exogenous T3, but not estradiol, rescued the reduced heart rate phenotype in gper mutant embryos, demonstrating that T3 acts downstream of GPER to regulate heart rate. Using genetic and mass spectrometry approaches, we find that GPER regulates maternal estrogen levels, which are required for normal embryonic heart rate. Our results demonstrate that estradiol plays a previously unappreciated role in the acute modulation of heart rate during zebrafish embryonic development and suggest that GPER regulates embryonic heart rate by altering maternal estrogen levels and embryonic T3 levels.

Accuracy of smartphone apps for heart rate measurement.

PubMed

Coppetti, Thomas; Brauchlin, Andreas; Müggler, Simon; Attinger-Toller, Adrian; Templin, Christian; Schönrath, Felix; Hellermann, Jens; Lüscher, Thomas F; Biaggi, Patric; Wyss, Christophe A

2017-08-01

Background Smartphone manufacturers offer mobile health monitoring technology to their customers, including apps using the built-in camera for heart rate assessment. This study aimed to test the diagnostic accuracy of such heart rate measuring apps in clinical practice. Methods The feasibility and accuracy of measuring heart rate was tested on four commercially available apps using both iPhone 4 and iPhone 5. 'Instant Heart Rate' (IHR) and 'Heart Fitness' (HF) work with contact photoplethysmography (contact of fingertip to built-in camera), while 'Whats My Heart Rate' (WMH) and 'Cardiio Version' (CAR) work with non-contact photoplethysmography. The measurements were compared to electrocardiogram and pulse oximetry-derived heart rate. Results Heart rate measurement using app-based photoplethysmography was performed on 108 randomly selected patients. The electrocardiogram-derived heart rate correlated well with pulse oximetry ( r = 0.92), IHR ( r = 0.83) and HF ( r = 0.96), but somewhat less with WMH ( r = 0.62) and CAR ( r = 0.60). The accuracy of app-measured heart rate as compared to electrocardiogram, reported as mean absolute error (in bpm ± standard error) was 2 ± 0.35 (pulse oximetry), 4.5 ± 1.1 (IHR), 2 ± 0.5 (HF), 7.1 ± 1.4 (WMH) and 8.1 ± 1.4 (CAR). Conclusions We found substantial performance differences between the four studied heart rate measuring apps. The two contact photoplethysmography-based apps had higher feasibility and better accuracy for heart rate measurement than the two non-contact photoplethysmography-based apps.

Rightward dominance in temporal high-frequency electrical asymmetry corresponds to higher resting heart rate and lower baroreflex sensitivity in a heterogeneous population.

PubMed

Tegeler, Charles H; Shaltout, Hossam A; Tegeler, Catherine L; Gerdes, Lee; Lee, Sung W

2015-06-01

Explore potential use of a temporal lobe electrical asymmetry score to discriminate between sympathetic and parasympathetic tendencies in autonomic cardiovascular regulation. 131 individuals (82 women, mean age 43.1, range 13-83) with diverse clinical conditions completed inventories for depressive (CES-D or BDI-II) and insomnia-related (ISI) symptomatology, and underwent five-minute recordings of heart rate and blood pressure, allowing calculation of heart rate variability and baroreflex sensitivity (BRS), followed by one-minute, two-channel, eyes-closed scalp recordings of brain electrical activity. A temporal lobe high-frequency (23-36 Hz) electrical asymmetry score was calculated for each subject by subtracting the average amplitude in the left temporal region from amplitude in the right temporal region, and dividing by the lesser of the two. Depressive and insomnia-related symptomatology exceeding clinical threshold levels were reported by 48% and 50% of subjects, respectively. Using a cutoff value of 5% or greater to define temporal high-frequency asymmetry, subjects with leftward compared to rightward asymmetry were more likely to report use of a sedative-hypnotic medication (42% vs. 22%, P = 0.02). Among subjects with asymmetry of 5% or greater to 30% or greater, those with rightward compared to leftward temporal high-frequency asymmetry had higher resting heart rate (≥5% asymmetry, 72.3 vs. 63.8, P = 0.004; ≥10%, 71.5 vs. 63.0, P = 0.01; ≥20%, 72.2 vs. 64.2, P = 0.05; ≥30%, 71.4 vs. 64.6, P = 0.05). Subjects with larger degrees of rightward compared to leftward temporal high-frequency asymmetry had lower baroreflex sensitivity (≥40% asymmetry, 10.6 vs. 16.4, P = 0.03; ≥50% asymmetry, 10.4 vs. 16.7, P = 0.05). In a heterogeneous population, individuals with rightward compared to leftward temporal high-frequency electrical asymmetry had higher resting heart rate and lower BRS. Two-channel recording of brain electrical activity from bilateral temporal regions appears to hold promise for further investigation as a means to assess cortical activity associated with autonomic cardiovascular regulation.

A protocol to study ex vivo mouse working heart at human-like heart rate.

PubMed

Feng, Han-Zhong; Jin, Jian-Ping

2018-01-01

Genetically modified mice are widely used as experimental models to study human heart function and diseases. However, the fast rate of normal mouse heart at 400-600bpm limits its capacity of assessing kinetic parameters that are important for the physiology and pathophysiology of human heart that beats at a much slower rate (75-180bpm). To extend the value of mouse models, we established a protocol to study ex vivo mouse working hearts at a human-like heart rate. In the presence of 300μM lidocaine to lower pacemaker and conductive activities and prevent arrhythmia, a stable rate of 120-130bpm at 37°C is achieved for ex vivo mouse working hearts. The negative effects of decreased heart rate on force-frequency dependence and lidocaine as a myocardial depressant on intracellular calcium can be compensated by using a higher but still physiological level of calcium (2.75mM) in the perfusion media. Multiple parameters were studied to compare the function at the human-like heart rate with that of ex vivo mouse working hearts at the standard rate of 480bpm. The results showed that the conditions for slower heart rate in the presence of 300μM lidocaine did not have depressing effect on left ventricular pressure development, systolic and diastolic velocities and stroke volume with maintained positive inotropic and lusitropic responses to β-adrenergic stimulation. Compared with that at 480bpm, the human-like heart rate increased ventricular filling and end diastolic volume with enhanced Frank-Starling responses. Coronary perfusion was increased from longer relaxation time and interval between beats whereas cardiac efficiency was significantly improved. Although the intrinsic differences between mouse and human heart remain, this methodology for ex vivo mouse hearts to work at human-like heart rate extends the value of using genetically modified mouse models to study cardiac function and human heart diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frame rate required for speckle tracking echocardiography: A quantitative clinical study with open-source, vendor-independent software.

PubMed

Negoita, Madalina; Zolgharni, Massoud; Dadkho, Elham; Pernigo, Matteo; Mielewczik, Michael; Cole, Graham D; Dhutia, Niti M; Francis, Darrel P

2016-09-01

To determine the optimal frame rate at which reliable heart walls velocities can be assessed by speckle tracking. Assessing left ventricular function with speckle tracking is useful in patient diagnosis but requires a temporal resolution that can follow myocardial motion. In this study we investigated the effect of different frame rates on the accuracy of speckle tracking results, highlighting the temporal resolution where reliable results can be obtained. 27 patients were scanned at two different frame rates at their resting heart rate. From all acquired loops, lower temporal resolution image sequences were generated by dropping frames, decreasing the frame rate by up to 10-fold. Tissue velocities were estimated by automated speckle tracking. Above 40 frames/s the peak velocity was reliably measured. When frame rate was lower, the inter-frame interval containing the instant of highest velocity also contained lower velocities, and therefore the average velocity in that interval was an underestimate of the clinically desired instantaneous maximum velocity. The higher the frame rate, the more accurately maximum velocities are identified by speckle tracking, until the frame rate drops below 40 frames/s, beyond which there is little increase in peak velocity. We provide in an online supplement the vendor-independent software we used for automatic speckle-tracked velocity assessment to help others working in this field. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.

PubMed

Wilson, Christopher M; Roa, Jinae N; Cox, Georgina K; Tresguerres, Martin; Farrell, Anthony P

2016-10-15

Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control. © 2016. Published by The Company of Biologists Ltd.

Cardiovascular responses associated with daily walking in subacute stroke.

PubMed

Prajapati, Sanjay K; Mansfield, Avril; Gage, William H; Brooks, Dina; McIlroy, William E

2013-01-01

Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1) walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%-60% heart rate reserve) or (2) heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve). Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve) and duration (>10 minutes continuously) necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.

Heart rate reduction and longevity in mice.

PubMed

Gent, Sabine; Kleinbongard, Petra; Dammann, Philip; Neuhäuser, Markus; Heusch, Gerd

2015-03-01

Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.

Abnormal heart rate recovery and deficient chronotropic response after submaximal exercise in young Marfan syndrome patients.

PubMed

Peres, Paulo; Carvalho, Antônio C; Perez, Ana Beatriz A; Medeiros, Wladimir M

2016-10-01

Marfan syndrome patients present important cardiac structural changes, ventricular dysfunction, and electrocardiographic changes. An abnormal heart rate response during or after exercise is an independent predictor of mortality and autonomic dysfunction. The aim of the present study was to compare heart rate recovery and chronotropic response obtained by cardiac reserve in patients with Marfan syndrome subjected to submaximal exercise. A total of 12 patients on β-blocker therapy and 13 off β-blocker therapy were compared with 12 healthy controls. They were subjected to submaximal exercise with lactate measurements. The heart rate recovery was obtained in the first minute of recovery and corrected for cardiac reserve and peak lactate concentration. Peak heart rate (141±16 versus 155±17 versus 174±8 bpm; p=0.001), heart rate reserve (58.7±9.4 versus 67.6±14.3 versus 82.6±4.8 bpm; p=0.001), heart rate recovery (22±6 versus 22±8 versus 34±9 bpm; p=0.001), and heart rate recovery/lactate (3±1 versus 3±1 versus 5±1 bpm/mmol/L; p=0.003) were different between Marfan groups and controls, respectively. All the patients with Marfan syndrome had heart rate recovery values below the mean observed in the control group. The absolute values of heart rate recovery were strongly correlated with the heart rate reserve (r=0.76; p=0.001). Marfan syndrome patients have reduced heart rate recovery and chronotropic deficit after submaximal exercise, and the chronotropic deficit is a strong determinant of heart rate recovery. These changes are suggestive of autonomic dysfunction.

A randomised, simulated study assessing auscultation of heart rate at birth.

PubMed

Voogdt, Kevin G J A; Morrison, Allison C; Wood, Fiona E; van Elburg, Ruurd M; Wyllie, Jonathan P

2010-08-01

Heart rate is a primary clinical indicator directing newborn resuscitation. The time taken to assess the heart rate by auscultation in relation to accuracy during newborn resuscitation is not known. To assess both the accuracy and time taken to assess heart rate by stethoscope in simulated resuscitation scenarios. The VitalSim((c)) manikin (Laerdal Medical, Stavanger, Norway) was used in this randomised, single blind study. Four heart rate settings (0, 40, 80, 120 beats per minute (bpm)) were randomly assigned. Participants assessed them by auscultation in three different scenarios. The first scenario was to assess the actual heart rate at birth. In the second scenario, heart rate was assessed during ventilation and assigned to standard ranges (<60, 60-100, >100bpm). In the third scenario, heart rate was assessed after three cycles of compressions and ventilation and assigned to standard ranges. In total 61 midwives, nurses and doctors performed 183 assessments. Mean time to estimate heart rate for scenarios 1, 2 and 3 was: 17.0, 9.8 and 7.8s respectively. Heart rate assessments were inaccurate in 31% (scenario 1), 28% (scenarios 2) and 26% (scenario 3). There was a trend for assessors who were accurate to be quicker and this achieved significance in scenario 2 (p<0.02). Inaccurate assessment would have made a difference to management in 28% of all cases. Mean time to estimate heart rate for the scenarios varied between 7.8 and 17.0s. Twenty-eight percent of all heart rate assessments would have prompted incorrect management during resuscitation or stabilization. Of incorrect assessments, 73% were overestimations. Further research is required to develop a rapid and accurate method for determining heart rate during newborn resuscitation. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Physiological responses to low atmospheric pressure stunning and the implications for welfare.

PubMed

McKeegan, D E F; Sandercock, D A; Gerritzen, M A

2013-04-01

In low atmospheric pressure stunning (LAPS), poultry are rendered unconscious before slaughter by gradually reducing oxygen tension in the atmosphere to achieve a progressive anoxia. The effects of LAPS are not instantaneous, so there are legitimate welfare concerns around the experience of birds before loss of consciousness. Using self-contained telemetry logging units, high-quality continuous electroencephalogram (EEG) and electrocardiogram (EKG) recordings were obtained from 28 broiler chickens during exposure to LAPS in a commercial poultry processing plant. Application of LAPS was associated with changes in the EEG pattern in the form of increases in total power, decreases in mean frequency, and in particular, increases in slow-wave (delta) activity, indicating a gradual loss of consciousness. Increased delta wave activity was seen within 10 s of LAPS onset and consistently thereafter, peaking at 30 s into LAPS at which point the EEG signal shared characteristics with that of birds in a surgical plane of anesthesia. During LAPS, heart rate consistently decreased, with more pronounced bradycardia and arrhythmia observed after 30 s. No heart rate increases were observed in the period when the birds were potentially conscious. After an initial quiescent period, brief body movements (presumed to be ataxia/loss of posture) were seen on average at 39 s into the LAPS process. Later (after 120 s on average), artifacts related to clonic (wing flapping) and tonic (muscle spasms) convulsions were observed in the EKG recordings. Based on EEG analysis and body movement responses, a conservative estimate of time to loss of consciousness is approximately 40 s. The lack of behavioral responses indicating aversion or escape and absence of heart rate elevation in the conscious period strongly suggest that birds do not find LAPS induction distressing. Collectively, the results suggest that LAPS is a humane approach that has the potential to improve the welfare of poultry at slaughter by gradually inducing unconsciousness without distress, eliminating live shackling and ensuring every bird is adequately stunned before exansguination.

Performance parameters and post exercise heart rate recovery in Warmblood sports horses of different performance levels.

PubMed

Bitschnau, C; Wiestner, T; Trachsel, D S; Auer, J A; Weishaupt, M A

2010-11-01

Standardised exercise tests are used for fitness evaluation of sports horses. Standards are described for Thoroughbreds and Standardbreds; however, limited information is available for Warmbloods. To establish normative standards of performance parameters and heart rate recovery (HRR) in Warmblood riding horses of different levels of fitness using a submaximal incremental exercise test (SIET) performed on a treadmill. A SIET was carried out with 29 healthy and treadmill-accustomed Warmbloods: eleven 3-day event horses (TDE) and 18 horses from the National Equestrian Centre (NEC) competing in amateur jumping and/or dressage events. After a warm-up phase, horses performed 2 stages at trot and 3-5 stages at gallop at 6% incline. The first stage lasted 120 s, all others 90 s. Velocity (V) and heart rate (HR) were measured continuously and blood lactate concentration (LAC) at the end of each exercise stage. V at HR 150 and 200 beats/min (V(150), V(200)), V and HR at 2 and 4 mmol/l LAC (V(2), V(4) and HR(2), HR(4), respectively) were calculated and compared between discipline groups. For reference values, horses were divided on the basis of the V(4) -results in good (GP) and average performers (AP) (performance groups). Five minute passive HRR was compared between performance groups. Fifteen NEC horses were retested within 1-3 months. Groups were compared with t tests and P < 0.05 considered significant. Three-day event horses had higher V(150), V(2) and V(4) values than NEC. GP had higher values in all performance parameters compared to AP. No differences were found between test and retest. GP mean recovery HR was different from that of AP from 120 s of recovery onwards. Treadmill SIETs are suitable to objectify aerobic capacity in Warmblood riding horses. Normative standards were assessed for well and averagely-trained horses. The results can be referred to when diagnosing patients with exercise intolerance. © 2010 EVJ Ltd.

Apnea of prematurity

MedlinePlus

... The baby may also have a: Drop in heart rate. This heart rate drop is called bradycardia or, sometimes, a "brady." ... hospital. The monitors keep track of their breathing, heart rate, and oxygen levels. Apnea, drop in heart rate, ...

Meta-Analysis of Medical Regimen Adherence Outcomes in Pediatric Solid Organ Transplantation*

PubMed Central

Dew, Mary Amanda; DeVito Dabbs, Annette; Myaskovsky, Larissa; Shyu, Susan; Shellmer, Diana A.; DiMartini, Andrea F.; Steel, Jennifer; Unruh, Mark; Switzer, Galen E.; Shapiro, Ron; Greenhouse, Joel B.

2009-01-01

Background Adherence to the medical regimen after pediatric organ transplantation is important for maximizing good clinical outcomes. However, the literature provides inconsistent evidence regarding prevalence and risk factors for nonadherence posttransplant. Methods A total of 61 studies (30 kidney, 18 liver, 8 heart, 2 lung/heart-lung, and 3 with mixed recipient samples) were included in a meta-analysis. Average rates of nonadherence to 6 areas of the regimen, and correlations of potential risk factors with nonadherence, were calculated. Results Across all types of transplantation, nonadherence to clinic appointments and tests was most prevalent, at 12.9 cases per 100 patients per year (PPY). The immunosuppression nonadherence rate was 6 cases per 100 PPY. Nonadherence to substance use restrictions, diet, exercise and other healthcare requirements ranged from 0.6 to 8 cases per 100 PPY. Only the rate of nonadherence to clinic appointments and tests varied by transplant type: heart recipients had the lowest rate (4.6 cases per 100 PPY vs. 12.7–18.8 cases per 100 PPY in other recipients). Older age of the child, family functioning (greater parental distress, lower family cohesion), and the child’s psychological status (poorer behavioral functioning, greater distress) were among the psychosocial characteristics significantly correlated with poorer adherence. These correlations were small to modest in size (r =.12–.18). Conclusions These nonadherence rates provide benchmarks for clinicians to use to estimate patient risk. The identified psychosocial correlates of nonadherence are potential targets for intervention. Future studies should focus on improving the prediction of nonadherence risk and on testing interventions to reduce risk. PMID:19741474

Control of heart rate during thermoregulation in the heliothermic lizard Pogona barbata: importance of cholinergic and adrenergic mechanisms.

PubMed

Seebacher, F; Franklin, C E

2001-12-01

During thermoregulation in the bearded dragon Pogona barbata, heart rate when heating is significantly faster than when cooling at any given body temperature (heart rate hysteresis), resulting in faster rates of heating than cooling. However, the mechanisms that control heart rate during heating and cooling are unknown. The aim of this study was to test the hypothesis that changes in cholinergic and adrenergic tone on the heart are responsible for the heart rate hysteresis during heating and cooling in P. barbata. Heating and cooling trials were conducted before and after the administration of atropine, a muscarinic antagonist, and sotalol, a beta-adrenergic antagonist. Cholinergic and beta-adrenergic blockade did not abolish the heart rate hysteresis, as the heart rate during heating was significantly faster than during cooling in all cases. Adrenergic tone was extremely high (92.3 %) at the commencement of heating, and decreased to 30.7 % at the end of the cooling period. Moreover, in four lizards there was an instantaneous drop in heart rate (up to 15 beats min(-1)) as the heat source was switched off, and this drop in heart rate coincided with either a drop in beta-adrenergic tone or an increase in cholinergic tone. Rates of heating were significantly faster during the cholinergic blockade, and least with a combined cholinergic and beta-adrenergic blockade. The results showed that cholinergic and beta-adrenergic systems are not the only control mechanisms acting on the heart during heating and cooling, but they do have a significant effect on heart rate and on rates of heating and cooling.

Adjustment of sleep and the circadian temperature rhythm after flights across nine time zones

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Myhre, Grete; Graeber, R. Curtis; Lauber, John K.; Andersen, Harald T.

1989-01-01

The adjustment of sleep-wake patterns and the circadian temperature rhythm was monitored in nine Royal Norwegian Airforce volunteers operating P-3 aircraft during a westward training deployment across nine time zones. Subjects recorded all sleep and nap times, rated nightly sleep quality, and completed personality inventories. Rectal temperature, heart rate, and wrist activity were continuously monitored. Adjustment was slower after the return eastward flight than after the outbound westward flight. The eastward flight produced slower readjustment of sleep timing to local time and greater interindividual variability in the patterns of adjustment of sleep and temperature. One subject apparently exhibited resynchronization by partition, with the temperature rhythm undergoing the reciprocal 15-h delay. In contrast, average heart rates during sleep were significantly elevated only after westward flight. Interindividual differences in adjustment of the temperature rhythm were correlated with some of the personality measures. Larger phase delays in the overall temperature waveform (as measured on the 5th day after westward flight) were exhibited by extraverts, and less consistently by evening types.

Development of a valid simulation assessment for a military dismounted assault task.

PubMed

Silk, Aaron J; Billing, Daniel C

2013-03-01

The Australian Defence Force is currently developing physical standards commensurate with job demands. Vital to this development process has been the accurate profiling of common military tasks. One such task required of all dismounted combat soldiers, an offensive assault on an enemy force, was the subject of in-depth profiling. In addition to overall assault performance, potential differences among patrol roles (scout, gunner, and flank) were investigated. Three different mock assaults of 100 to 150 m were performed by three patrols comprising qualified experienced infantry soldiers. Each soldier was fitted with a heart rate monitor and wore a global positioning device. Average assault duration was 6.5 minutes and required nineteen 7-m bounds performed on a 22-seconds duty cycle at 75% heart rate reserve and a work to rest ratio 1:4. Assaults conducted in more densely vegetated terrain resulted in significantly reduced (p < 0.05) bound distance, bound duration, and movement velocity. Results indicated significant performance differences (p < 0.05) among patrol roles for external load carried, heart rate response, bound duration, and distance covered while movement velocity was not different (p > 0.05). As a result of profiling the assault task, a valid simulation capable of assessing soldiers' physical capacity to perform this task was developed. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Measuring hospital performance in congenital heart surgery: Administrative vs. clinical registry data

PubMed Central

Pasquali, Sara K.; He, Xia; Jacobs, Jeffrey P.; Jacobs, Marshall L.; Gaies, Michael G.; Shah, Samir S.; Hall, Matthew; Gaynor, J. William; Peterson, Eric D.; Mayer, John E.; Hirsch-Romano, Jennifer C.

2015-01-01

Background In congenital heart surgery, hospital performance has historically been assessed using widely available administrative datasets. Recent studies have demonstrated inaccuracies in case ascertainment (coding and inclusion of eligible cases) in administrative vs. clinical registry data, however it is unclear whether this impacts assessment of performance on a hospital-level. Methods Merged data from the Society of Thoracic Surgeons (STS) Database (clinical registry), and Pediatric Health Information Systems Database (administrative dataset) on 46,056 children undergoing heart surgery (2006–2010) were utilized to evaluate in-hospital mortality for 33 hospitals based on their administrative vs. registry data. Standard methods to identify/classify cases were used: Risk Adjustment in Congenital Heart Surgery (RACHS-1) in the administrative data, and STS–European Association for Cardiothoracic Surgery (STAT) methodology in the registry. Results Median hospital surgical volume based on the registry data was 269 cases/yr; mortality was 2.9%. Hospital volumes and mortality rates based on the administrative data were on average 10.7% and 4.7% lower, respectively, although this varied widely across hospitals. Hospital rankings for mortality based on the administrative vs. registry data differed by ≥ 5 rank-positions for 24% of hospitals, with a change in mortality tertile classification (high, middle, or low mortality) for 18%, and change in statistical outlier classification for 12%. Higher volume/complexity hospitals were most impacted. Agency for Healthcare Quality and Research methods in the administrative data yielded similar results. Conclusions Inaccuracies in case ascertainment in administrative vs. clinical registry data can lead to important differences in assessment of hospital mortality rates for congenital heart surgery. PMID:25624057

Gender- and age-related differences in heart rate dynamics: are women more complex than men?

NASA Technical Reports Server (NTRS)

Ryan, S. M.; Goldberger, A. L.; Pincus, S. M.; Mietus, J.; Lipsitz, L. A.

1994-01-01

OBJECTIVES. This study aimed to quantify the complex dynamics of beat-to-beat sinus rhythm heart rate fluctuations and to determine their differences as a function of gender and age. BACKGROUND. Recently, measures of heart rate variability and the nonlinear "complexity" of heart rate dynamics have been used as indicators of cardiovascular health. Because women have lower cardiovascular risk and greater longevity than men, we postulated that there are important gender-related differences in beat-to-beat heart rate dynamics. METHODS. We analyzed heart rate dynamics during 8-min segments of continuous electrocardiographic recording in healthy young (20 to 39 years old), middle-aged (40 to 64 years old) and elderly (65 to 90 years old) men (n = 40) and women (n = 27) while they performed spontaneous and metronomic (15 breaths/min) breathing. Relatively high (0.15 to 0.40 Hz) and low (0.01 to 0.15 Hz) frequency components of heart rate variability were computed using spectral analysis. The overall "complexity" of each heart rate time series was quantified by its approximate entropy, a measure of regularity derived from nonlinear dynamics ("chaos" theory). RESULTS. Mean heart rate did not differ between the age groups or genders. High frequency heart rate power and the high/low frequency power ratio decreased with age in both men and women (p < 0.05). The high/low frequency power ratio during spontaneous and metronomic breathing was greater in women than men (p < 0.05). Heart rate approximate entropy decreased with age and was higher in women than men (p < 0.05). CONCLUSIONS. High frequency heart rate spectral power (associated with parasympathetic activity) and the overall complexity of heart rate dynamics are higher in women than men. These complementary findings indicate the need to account for gender-as well as age-related differences in heart rate dynamics. Whether these gender differences are related to lower cardiovascular disease risk and greater longevity in women requires further study.

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders.

PubMed

den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; St Pourcain, Beate; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-Liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F

2013-06-01

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

Metabolic and cardiovascular adjustment to work in air and water at 18, 25, and 33 degrees C.

PubMed

McArdle, W D; Magel, J R; Lesmes, G R; Pechar, G S

1976-01-01

By use of successive increments of discontinuous work with an arm-leg cycle ergometer the VO2, Q, SV, and HR were studied in six male subjects at rest and during exercise in air and in water at 18, 25, and 33 degrees C. The Q values obtained by CO2 rebreathing were reproducible. VO2 was linearly related to work with the plots for air and 33 degrees C water being similar. However, during work in 25 and 18 degrees C water, the VO2 averaged 9.0% (150 ml) and 25.3% (400 ml) higher, respectively, than values observed in 33 degrees C water, with the largest differences observed in leaner subjects. The plot of HR-VO2 was linear and almost identical during work in air and 33 degrees C water, but shifted significantly to the right in cooler water. VO2 averaged 250-700 ml higher in cold water compared to air and 33 degrees C water at a given mean heart rate. The Q vs. VO2 line was similar during work in air and in water with no effect of water or temperature. At similar levels of VO2, SV was significantly larger (P less than 0.05) in 25 and 18 degrees C water than in air or 33 degrees C water. Consequently, the reduction in heart rate during work in cold water was entirely compensated for by a proportionate increase in the SV of the heart. Q was therefore maintained at similar levels of energy expenditure in air and in 18, 25, and 30 degrees C water.

Autonomic mechanisms of muscle metaboreflex control of heart rate.

PubMed

O'Leary, D S

1993-04-01

Ischemia in active skeletal muscle induces reflex increases in systemic arterial pressure (SAP) and heart rate (HR), termed the muscle metaboreflex. When metaboreflex activation is maintained during postexercise muscle ischemia, SAP remains elevated; however, HR decreases. Why the HR responses differ with metaboreflex activation during exercise vs. during postexercise ischemia while the SAP responses are similar in each setting remains unclear. Two hypotheses were tested: 1) the increase in HR with muscle ischemia occurs predominantly via an increase in sympathetic activity, and 2) sympathetic activity to the heart remains elevated during post-exercise ischemia; however, HR decreases because of an increase in parasympathetic outflow. The muscle metaboreflex was activated in conscious dogs during treadmill exercise (3.2 kph, 0% grade) by progressively decreasing perfusion to the hindlimbs. Experiments were performed before and after muscarinic (atropine) or beta- (atenolol or propranolol) receptor blockade. In control experiments, once beyond the threshold for the reflex, the HR sensitivity of the muscle metaboreflex averaged -2.4 +/- 0.3 beats.min-1.mmHg-1 and the reflex open-loop gain averaged -3.2 +/- 0.3 (calculated as the ratio of the increase in HR or SAP to the decrease in hindlimb perfusion pressure beyond threshold). Atropine had no effect on either HR sensitivity (-2.7 +/- 0.4 beats.min-1.mmHg-1) or open-loop gain (-3.3 +/- 0.5, both P > 0.05 vs. control). However, pretreatment with beta-receptor antagonist significantly decreased both HR sensitivity (-0.7 +/- 0.1 beats.min-1.mmHg-1, P < 0.001) and open-loop gain (-1.9 +/- 0.3, P < 0.01). During postexercise ischemia, HR decreased while SAP remained elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended dynamic range of Doppler OCT by application of a new method to high density B-scans using a MHz FDML swept laser source (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elahi, Sahar; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

2017-02-01

The limited dynamic range of optical coherence tomography (OCT) Doppler velocity measurements makes it difficult to conduct experiments on samples requiring a large dynamic range without phase wrapping at high velocities or loss of sensitivity at slow velocities. Hemodynamics and wall motion undergo significant increases in velocity as the embryonic heart develops. Experimental studies indicate that altered hemodynamics in early-stage embryonic hearts can lead to congenital heart diseases (CHDs), motivating close monitoring of blood flow over several stages of development. We have built a high-speed OCT system using an FDML laser (Optores GmbH, Germany) at a sweep rate of 1.68 MHz (axial resolution - 12 μm, sensitivity - 105 dB, phase stability - 17 mrad). The speed of this OCT system allows us to acquire high-density B-scans to obtain an extended velocity dynamic range without sacrificing the frame rate (100 Hz). The extended dynamic range within a frame is achieved by varying the A-scan interval at which the phase difference is found, enabling detection of velocities ranging from tens of microns per second to hundreds of millimeters per second. The extra lines in a frame can also be utilized to improve the structural and Doppler images via complex averaging. In structural images where the presence of blood causes additional scattering, complex averaging helps retrieve features located deeper in the tissue. Moreover, high-density frames can be registered to 4D volumes to determine the orthogonal direction of flow for calculating shear stress as well as estimating the cardiac output. In conclusion, high density B-scans acquired by our high-speed OCT system enable image enhancement and direct measurement of biological parameters in cohort studies.

Automatic estimation of heart boundaries and cardiothoracic ratio from chest x-ray images

NASA Astrophysics Data System (ADS)

Dallal, Ahmed H.; Agarwal, Chirag; Arbabshirani, Mohammad R.; Patel, Aalpen; Moore, Gregory

2017-03-01

Cardiothoracic ratio (CTR) is a widely used radiographic index to assess heart size on chest X-rays (CXRs). Recent studies have suggested that also two-dimensional CTR might contain clinical information about the heart function. However, manual measurement of such indices is both subjective and time consuming. This study proposes a fast algorithm to automatically estimate CTR indices based on CXRs. The algorithm has three main steps: 1) model based lung segmentation, 2) estimation of heart boundaries from lung contours, and 3) computation of cardiothoracic indices from the estimated boundaries. We extended a previously employed lung detection algorithm to automatically estimate heart boundaries without using ground truth heart markings. We used two datasets: a publicly available dataset with 247 images as well as clinical dataset with 167 studies from Geisinger Health System. The models of lung fields are learned from both datasets. The lung regions in a given test image are estimated by registering the learned models to patient CXRs. Then, heart region is estimated by applying Harris operator on segmented lung fields to detect the corner points corresponding to the heart boundaries. The algorithm calculates three indices, CTR1D, CTR2D, and cardiothoracic area ratio (CTAR). The method was tested on 103 clinical CXRs and average error rates of 7.9%, 25.5%, and 26.4% (for CTR1D, CTR2D, and CTAR respectively) were achieved. The proposed method outperforms previous CTR estimation methods without using any heart templates. This method can have important clinical implications as it can provide fast and accurate estimate of cardiothoracic indices.

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

PubMed

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses (e.g., heart rate, core temperature).

Differences in energy expenditure and substrate oxidation between habitual high fat and low fat consumers (phenotypes).

PubMed

Cooling, J; Blundell, J

1998-07-01

To investigate physiological differences between habitual high-fat (HF) and low-fat (LF) consumers, which could influence the balance between energy expenditure and energy intake, and the potential for weight gain. 16 young, lean males (eight HF and eight LF consumers; % energy from fat 44.3 and 32.0, respectively). Habitual dietary variables (from FFQ), body mass index (BMI), body fat % (measured by impedance), resting metabolic rate (RMR) (indirect calorimetry), substrate oxidation and basal heart rate, postprandial thermogenesis and heart rate in response to a high-fat (low carbohydrate (CHO)) and high-CHO (low fat) challenge. HF and LF (selected for their intake of fat) did not differ significantly in BMI or % body fat. HF had a significantly higher RMR (1624 vs 1455 kcal/d) and basal heart rate (66 vs 57 bpm) than LF. Differences in oxygen utilisation and heart rate were maintained over a 180 min period, following the high-fat and high-CHO challenge meals. HF had a significantly lower resting respiratory quotient (RQ) than LF and the differences in average RQ were significant over the 180 min examination period. HF had a significantly lower RQ response to the high fat (low CHO) than to the high CHO (low fat) challenge; this effect was not observed in LF. HF had higher total energy intake than LF and a higher absolute (but not %) intake of protein. Significant differences in basal energy expenditure and fat oxidation between habitual HF and LF consumers have been observed. The contributions of energy intake and protein intake (g not %) remain to be determined. In this particular group of subjects (young adult males) a high energy intake characterised by a large fat component is associated with metabolic adaptations which could offset the weight inducing properties of a high-fat diet. These physiological differences may be important when considering the relationship between dietary-fat and obesity.

Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

PubMed Central

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses (e.g., heart rate, core temperature). PMID:26379284

Effect of pedal rate and power output on rating of perceived exertion during cycle ergometry exercise.

PubMed

Hamer, Mark; Boutcher, Yati N; Boutcher, Stephen H

2005-12-01

This study examined differentiated rating of perceived exertion (RPE), heart rate, and heart-rate variability during light cycle ergometry exercise at two different pedal rates. 30 healthy men (22.6 +/- 0.9 yr.) were recruited from a student population and completed a continuous 20-min. cycle ergometry exercise protocol, consisting of a 4-min. warm-up (60 rev./min., 30 Watts), followed by four bouts of 4 min. at different combinations of pedal rate (40 or 80 rev./min.) and power output (40 or 80 Watts). The order of the four combinations was counterbalanced across participants. Heart rate was measured using a polar heart-rate monitor, and parasympathetic balance was assessed through time series analysis of heart-rate variability. Measures were compared using a 2 (pedal rate) x 2 (power output) repeated-measures analysis of variance. RPE was significantly greater (p<.05) at 80 versus 40 rev./min. at 40 W. For both power outputs heart rate was significantly increased, and the high frequency component of heart-rate variability was significantly reduced at 80 compared with 40 rev./min. These findings indicate the RPE was greater at higher than at lower pedalling rates for a light absolute power output which contrasts with previous findings based on use of higher power output. Also, pedal rate had a significant effect on heart rate and heart-rate variability at constant power output.

Heart rate variability in patients with systemic lupus erythematosus: a systematic review and methodological considerations.

PubMed

Matusik, P S; Matusik, P T; Stein, P K

2018-07-01

Aim The aim of this review was to summarize current knowledge about the scientific findings and potential clinical utility of heart rate variability measures in patients with systemic lupus erythematosus. Methods PubMed, Embase and Scopus databases were searched for the terms associated with systemic lupus erythematosus and heart rate variability, including controlled vocabulary, when appropriate. Articles published in English and available in full text were considered. Finally, 11 publications were selected, according to the systematic review protocol and were analyzed. Results In general, heart rate variability, measured in the time and frequency domains, was reported to be decreased in patients with systemic lupus erythematosus compared with controls. In some systemic lupus erythematosus studies, heart rate variability was found to correlate with inflammatory markers and albumin levels. A novel heart rate variability measure, heart rate turbulence onset, was shown to be increased, while heart rate turbulence slope was decreased in systemic lupus erythematosus patients. Reports of associations of changes in heart rate variability parameters with increasing systemic lupus erythematosus activity were inconsistent, showing decreasing heart rate variability or no relationship. However, the low/high frequency ratio was, in some studies, reported to increase with increasing disease activity or to be inversely correlated with albumin levels. Conclusions Patients with systemic lupus erythematosus have abnormal heart rate variability, which reflects cardiac autonomic dysfunction and may be related to inflammatory cytokines but not necessarily to disease activity. Thus measurement of heart rate variability could be a useful clinical tool for monitoring autonomic dysfunction in systemic lupus erythematosus, and may potentially provide prognostic information.

Congenital heart disease infant death rates decrease as gestational age advances from 34 to 40 weeks.

PubMed

Cnota, James F; Gupta, Resmi; Michelfelder, Erik C; Ittenbach, Richard F

2011-11-01

To describe congenital heart disease death rates in infants born between 34 and 40 weeks, estimate the relationship between gestational age and congenital heart disease infant death rates, and compare congenital heart disease death rates across 1- and 2-week intervals in gestational age. The 2000 to 2003 national linked birth/infant death cohort datasets were obtained. Congenital heart disease deaths were identified by using International Statistical Classification of Diseases, 10th Revision codes. Proportional death rates were calculated by using congenital heart disease deaths and all live births. The relationship between congenital heart disease death rates and gestational age was determined. Death rates were compared across intervals. A total of 14.9 million records were analyzed. Congenital heart disease deaths occurred in 4736 infants (0.04%) born between 34 and 40 weeks. There was a significant, negative linear relationship between congenital heart disease death rate and gestational age (R(2) = 0.97). Comparisons across 1-week intervals varied (P = .02-.23). All 2-week intervals were statistically significant (P < .01). Congenital heart disease death rates decrease as gestational age approaches 40 weeks. These results should be considered before elective delivery for the sole indication of prenatally diagnosed congenital heart disease. Copyright © 2011 Mosby, Inc. All rights reserved.

ACCF/AHA/HFSA 2011 survey results: current staffing profile of heart failure programs, including programs that perform heart transplant and mechanical circulatory support device implantation.

PubMed

Jessup, Mariell; Albert, Nancy M; Lanfear, David E; Lindenfeld, JoAnn; Massie, Barry M; Walsh, Mary Norine; Zucker, Mark J

2011-05-01

There have been no published recommendations about staffing needs for a heart failure (HF) clinic or an office setting focused on heart transplant. The goal of this survey was to understand the current staffing environment of HF, transplant, and mechanical circulatory support device (MCSD) programs in the United States and abroad. This report identifies current staffing patterns but does not endorse a particular staffing model. An online survey, jointly sponsored by the American College of Cardiology Foundation (ACCF), American Heart Association (AHA), and the Heart Failure Society of America (HFSA), was sent to the members of all 3 organizations who had identified themselves as interested in HF, heart transplant, or both, between March 12, 2009, and May 12, 2009. The overall response rate to the 1,823 e-mail surveys was 23%. There were 257 unique practices in the United States (81% of total sites) and 58 international sites (19%); approximately 30% of centers were in a cardiovascular group practice and 30% in a medical school hospital setting. The large majority of practices delivered HF care in both an inpatient and outpatient environment, and slightly more centers were implanting MCSDs (47%) than performing cardiac transplantation (39%). Most practices (43%) were small, with <4 staff members, or small- to medium-sized (34%), with 4 to 10 staff members, with only 23% being medium (11-20 staff) or large programs (>20 staff). On average, a U.S. HF practice cared for 1,641 outpatients annually. An average HF program with transplant performed 10 transplants. Although larger programs were able to perform more transplants and see more outpatient HF visits, their clinician staffing volume tended to double for approximately every 500 to 700 additional HF visits annually. The average staffing utilization was 2.65 physician full-time equivalents (FTEs), 2.21 nonphysician practitioner (nurse practitioner or physician assistant) FTEs, and 2.61 nurse coordinator FTEs annually. The HF patient population is growing in number in the United States and internationally, and the clinicians who provide the highly skilled and time-consuming care to this population are under intense scrutiny as a result of focused quality improvement initiatives and reduced financial resources. Staffing guidelines should be developed to ensure that an adequate number of qualified professionals are hired for a given practice volume. These survey results are an initial step in developing such standards. Copyright © 2011. Published by Elsevier Inc.

The predictive value of resting heart rate following osmotherapy in brain injury: back to basics.

PubMed

Hasanpour Mir, Mahsa; Yousefshahi, Fardin; Abdollahi, Mohammad; Ahmadi, Arezoo; Nadjafi, Atabak; Mojtahedzadeh, Mojtaba

2012-12-30

The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS) and the mortality due to MODS is highly correlated with inadequate sinus tachycardia.To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II), Sequential Organ Failure Assessment (SOFA) and Glasgow Coma Score (GCS). By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline), heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07). Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury.

Parenting Behaviors, Parent Heart Rate Variability, and Their Associations with Adolescent Heart Rate Variability.

PubMed

Graham, Rebecca A; Scott, Brandon G; Weems, Carl F

2017-05-01

Adolescence is a potentially important time in the development of emotion regulation and parenting behaviors may play a role. We examined associations among parenting behaviors, parent resting heart rate variability, adolescent resting heart rate variability and parenting behaviors as moderators of the association between parent and adolescent resting heart rate variability. Ninety-seven youth (11-17 years; 49.5 % female; 34 % African American, 37.1 % Euro-American, 22.6 % other/mixed ethnic background, and 7.2 % Hispanic) and their parents (n = 81) completed a physiological assessment and questionnaires assessing parenting behaviors. Inconsistent discipline and corporal punishment were negatively associated with adolescent resting heart rate variability, while positive parenting and parental involvement were positively associated. Inconsistent discipline and parental involvement moderated the relationship between parent and adolescent resting heart rate variability. The findings provide evidence for a role of parenting behaviors in shaping the development of adolescent resting heart rate variability with inconsistent discipline and parental involvement potentially influencing the entrainment of resting heart rate variability in parents and their children.

Prostaglandins are important in thermoregulation of a reptile (Pogona vitticeps).

PubMed Central

Seebacher, Frank; Franklin, Craig E

2003-01-01

The effectiveness of behavioural thermoregulation in reptiles is amplified by cardiovascular responses, particularly by differential rates of heart beat in response to heating and cooling (heart-rate hysteresis). Heart-rate hysteresis is ecologically important in most lineages of ectothermic reptile, and we demonstrate that heart-rate hysteresis in the lizard Pogona vitticeps is mediated by prostaglandins. In a control treatment (administration of saline), heart rates during heating were significantly faster than during cooling at any given body temperature. When cyclooxygenase 1 and 2 enzymes were inhibited, heart rates during heating were not significantly different from those during cooling. Administration of agonists showed that thromboxane B(2) did not have a significant effect on heart rate, but prostacyclin and prostaglandin F(2alpha) caused a significant increase (3.5 and 13.6 beats min(-1), respectively) in heart rate compared with control treatments. We speculate that heart-rate hysteresis evolved as a thermoregulatory mechanism that may ultimately be controlled by neurally induced stimulation of nitric oxide production, or maybe via photolytically induced production of vitamin D. PMID:12952634

Prostaglandins are important in thermoregulation of a reptile (Pogona vitticeps).

PubMed

Seebacher, Frank; Franklin, Craig E

2003-08-07

The effectiveness of behavioural thermoregulation in reptiles is amplified by cardiovascular responses, particularly by differential rates of heart beat in response to heating and cooling (heart-rate hysteresis). Heart-rate hysteresis is ecologically important in most lineages of ectothermic reptile, and we demonstrate that heart-rate hysteresis in the lizard Pogona vitticeps is mediated by prostaglandins. In a control treatment (administration of saline), heart rates during heating were significantly faster than during cooling at any given body temperature. When cyclooxygenase 1 and 2 enzymes were inhibited, heart rates during heating were not significantly different from those during cooling. Administration of agonists showed that thromboxane B(2) did not have a significant effect on heart rate, but prostacyclin and prostaglandin F(2alpha) caused a significant increase (3.5 and 13.6 beats min(-1), respectively) in heart rate compared with control treatments. We speculate that heart-rate hysteresis evolved as a thermoregulatory mechanism that may ultimately be controlled by neurally induced stimulation of nitric oxide production, or maybe via photolytically induced production of vitamin D.

Oxygen Saturation in Healthy Children Aged 5 to 16 Years Residing in Huayllay, Peru at 4340 m

PubMed Central

Schult, Sandra

2011-01-01

Abstract Schult, Sandra, and Carlos Canelo-Aybar. Oxygen saturation in healthy chidren aged 5 to 6 years residing in Huayllay, Peru, at 4340 m. High Alt. Med. Biol. 12:89–92, 2011.—Hypoxemia is a major life-threatening complication of childhood pneumonia. The threshold points for hypoxemia vary with altitude. However, few published data describe that normal range of variation. The purpose of this study was to establish reference values of normal mean Sao2 levels and an approximate cutoff point to define hypoxemia for clinical purposes above 4300 meters above sea level (masl). Children aged 5 to 16 yr were examined during primary care visits at the Huayllay Health Center. Huayllay is a rural community located at 4340 m in the province of Pasco in the Peruvian Andes. We collected basic sociodemographic data and evaluated three outcomes: arterial oxygen saturation (Sao2) with a pulse oximeter, heart rate, and respiratory rate. Comparisons of main outcomes among age groups (5–6, 7–8, 9–10, 11–12, 13–14, and 15–16 yr) and sex were performed using linear regression models. The correlation of Sao2 with heart rate and respiration rate was established by Pearson's correlation test. We evaluated 583 children, of whom 386 were included in the study. The average age was 10.3 yr; 55.7% were female. The average Sao2, heart rate, and respiratory rate were 85.7% (95% CI: 85.2–86.2), 80.4/min (95% CI: 79.0–81.9), and 19.9/min (95% CI: 19.6–20.2), respectively. Sao2 increased with age (p < 0.001). No differences by sex were observed. The mean minus two standard deviations of Sao2 (threshold point for hypoxemia) ranged from 73.8% to 81.8% by age group. At 4300 m, the reference values for hypoxemia may be 14.2% lower than at sea level. This difference must be considered when diagnosing hypoxemia or deciding oxygen supplementation at high altitude. Other studies are needed to determine whether this reference value is appropriate for clinical use. PMID:21452970

Relationship between heart rate and quiescent interval of the cardiac cycle in children using MRI.

PubMed

Zhang, Wei; Bogale, Saivivek; Golriz, Farahnaz; Krishnamurthy, Rajesh

2017-11-01

Imaging the heart in children comes with the challenge of constant cardiac motion. A prospective electrocardiography-triggered CT scan allows for scanning during a predetermined phase of the cardiac cycle with least motion. This technique requires knowing the optimal quiescent intervals of cardiac cycles in a pediatric population. To evaluate high-temporal-resolution cine MRI of the heart in children to determine the relationship of heart rate to the optimal quiescent interval within the cardiac cycle. We included a total of 225 consecutive patients ages 0-18 years who had high-temporal-resolution cine steady-state free-precession sequence performed as part of a magnetic resonance imaging (MRI) or magnetic resonance angiography study of the heart. We determined the location and duration of the quiescent interval in systole and diastole for heart rates ranging 40-178 beats per minute (bpm). We performed the Wilcoxon signed rank test to compare the duration of quiescent interval in systole and diastole for each heart rate group. The duration of the quiescent interval at heart rates <80 bpm and >90 bpm was significantly longer in diastole and systole, respectively (P<.0001 for all ranges, except for 90-99 bpm [P=.02]). For heart rates 80-89 bpm, diastolic interval was longer than systolic interval, but the difference was not statistically significant (P=.06). We created a chart depicting optimal quiescent intervals across a range of heart rates that could be applied for prospective electrocardiography-triggered CT imaging of the heart. The optimal quiescent interval at heart rates <80 bpm is in diastole and at heart rates ≥90 bpm is in systole. The period of quiescence at heart rates 80-89 bpm is uniformly short in systole and diastole.

The Accuracy and Validity of iOS-Based Heart Rate Apps During Moderate to High Intensity Exercise.

PubMed

Bouts, Alexa M; Brackman, Lauren; Martin, Elizabeth; Subasic, Adam M; Potkanowicz, Edward S

2018-01-01

People use their smartphones for everything from web browsing to tracking fitness metrics. However, it is unclear whether smartphone-based apps that use photoplethysmography to measure heart rate are an accurate or valid measure of exercise intensity. Purpose was to determine the accuracy and validity of two iOS-based heart rate monitors, Runtastic Heart Rate Monitor and Pulse Tracker PRO by Runtastic (Runtastic) and Instant Heart Rate+: Heart Rate and Pulse Monitor by Azumio (Instant Heart Rate), when compared to the electrocardiogram (ECG) and Polar® T31 uncoded heart rate monitor from moderate to vigorous intensity exercise. Participants were 15 male and female regularly active college students. Pre-exercise heart rate and blood pressure were recorded and then participants exercised on a stationary bike at a pedal rate of between 50-60 rpms. After completing a warm-up stage at 40% of age estimated maximum heart rate (AEMHR), exercise intensity progressed from 50% of AEMHR through to 85% of AEMHR in eight, 5-minute stages. At the end of each stage, and having achieved steady-state, heart rates were recorded from each apparatus. After completing the final stage, participants completed a cooldown at 40% of their AEMHR. Post-exercise heart rate and blood pressure were also recorded to ensure full recovery to baseline. There was a strong positive correlation between the Polar® monitor and the ECG during all stages. However, there were not strong correlations for either of the smartphone-based apps at any time point. Although there were weak correlations between the smartphone-based apps and ECG and Polar®, further studies need to be conducted to determine if inaccuracy is due to user error (finger placement, finger temperature, etc.) or the technology behind the apps.

The Accuracy and Validity of iOS-Based Heart Rate Apps During Moderate to High Intensity Exercise

PubMed Central

BOUTS, ALEXA M.; BRACKMAN, LAUREN; MARTIN, ELIZABETH; SUBASIC, ADAM M.; POTKANOWICZ, EDWARD S.

2018-01-01

People use their smartphones for everything from web browsing to tracking fitness metrics. However, it is unclear whether smartphone-based apps that use photoplethysmography to measure heart rate are an accurate or valid measure of exercise intensity. Purpose was to determine the accuracy and validity of two iOS-based heart rate monitors, Runtastic Heart Rate Monitor and Pulse Tracker PRO by Runtastic (Runtastic) and Instant Heart Rate+: Heart Rate and Pulse Monitor by Azumio (Instant Heart Rate), when compared to the electrocardiogram (ECG) and Polar® T31 uncoded heart rate monitor from moderate to vigorous intensity exercise. Participants were 15 male and female regularly active college students. Pre-exercise heart rate and blood pressure were recorded and then participants exercised on a stationary bike at a pedal rate of between 50–60 rpms. After completing a warm-up stage at 40% of age estimated maximum heart rate (AEMHR), exercise intensity progressed from 50% of AEMHR through to 85% of AEMHR in eight, 5-minute stages. At the end of each stage, and having achieved steady-state, heart rates were recorded from each apparatus. After completing the final stage, participants completed a cooldown at 40% of their AEMHR. Post-exercise heart rate and blood pressure were also recorded to ensure full recovery to baseline. There was a strong positive correlation between the Polar® monitor and the ECG during all stages. However, there were not strong correlations for either of the smartphone-based apps at any time point. Although there were weak correlations between the smartphone-based apps and ECG and Polar®, further studies need to be conducted to determine if inaccuracy is due to user error (finger placement, finger temperature, etc.) or the technology behind the apps. PMID:29541341

Arrhythmias (For Parents)

MedlinePlus

... or a heart function test. What's a Normal Heart Rate? Heart rate is measured by counting the number of beats per minute. Someone's normal heart rate depends on things like the person's age and ...

Estimating 'lost heart beats' rather than reductions in heart rate during the intubation of critically-ill children.

PubMed

Jones, Peter; Ovenden, Nick; Dauger, Stéphane; Peters, Mark J

2014-01-01

Reductions in heart rate occur frequently in children during critical care intubation and are currently considered the gold standard for haemodynamic instability. Our objective was to estimate loss of heart beats during intubation and compare this to reduction in heart rate alone whilst testing the impact of atropine pre-medication. Data were extracted from a prospective 2-year cohort study of intubation ECGs from critically ill children in PICU/Paediatric Transport. A three step algorithm was established to exclude variation in pre-intubation heart rate (using a 95%CI limit derived from pre-intubation heart rate variation of the children included), measure the heart rate over time and finally the estimate the numbers of lost beats. 333 intubations in children were eligible for inclusion of which 245 were available for analysis (74%). Intubations where the fall in heart rate was less than 50 bpm were accompanied almost exclusively by less than 25 lost beats (n = 175, median 0 [0-1]). When there was a reduction of >50 bpm there was a poor correlation with numbers of lost beats (n = 70, median 42 [15-83]). During intubation the median number of lost beats was 8 [1]-[32] when atropine was not used compared to 0 [0-0] when atropine was used (p<0.001). A reduction in heart rate during intubation of <50 bpm reliably predicted a minimal loss of beats. When the reduction in heart rate was >50 bpm the heart rate was poorly predictive of lost beats. A study looking at the relationship between lost beats and cardiac output needs to be performed. Atropine reduces both fall in heart rate and loss of beats. Similar area-under-the-curve methodology may be useful for estimating risk when biological parameters deviate outside normal range.

Predominance of Intrinsic Mechanism of Resting Heart Rate Control and Preserved Baroreflex Sensitivity in Professional Cyclists after Competitive Training.

PubMed

Azevedo, Luciene Ferreira; Perlingeiro, Patricia; Hachul, Denise Tessariol; Gomes-Santos, Igor Lucas; Tsutsui, Jeane Mike; Negrao, Carlos Eduardo; De Matos, Luciana D N J

2016-01-01

Different season trainings may influence autonomic and non-autonomic cardiac control of heart rate and provokes specific adaptations on heart's structure in athletes. We investigated the influence of transition training (TT) and competitive training (CT) on resting heart rate, its mechanisms of control, spontaneous baroreflex sensitivity (BRS) and relationships between heart rate mechanisms and cardiac structure in professional cyclists (N = 10). Heart rate (ECG) and arterial blood pressure (Pulse Tonometry) were recorded continuously. Autonomic blockade was performed (atropine-0.04 mg.kg-1; esmolol-500 μg.kg-1 = 0.5 mg). Vagal effect, intrinsic heart rate, parasympathetic (n) and sympathetic (m) modulations, autonomic influence, autonomic balance and BRS were calculated. Plasma norepinephrine (high-pressure liquid chromatography) and cardiac structure (echocardiography) were evaluated. Resting heart rate was similar in TT and CT. However, vagal effect, intrinsic heart rate, autonomic influence and parasympathetic modulation (higher n value) decreased in CT (P≤0.05). Sympathetic modulation was similar in both trainings. The autonomic balance increased in CT but still showed parasympathetic predominance. Cardiac diameter, septum and posterior wall thickness and left ventricular mass also increased in CT (P<0.05) as well as diastolic function. We observed an inverse correlation between left ventricular diastolic diameter, septum and posterior wall thickness and left ventricular mass with intrinsic heart rate. Blood pressure and BRS were similar in both trainings. Intrinsic heart rate mechanism is predominant over vagal effect during CT, despite similar resting heart rate. Preserved blood pressure levels and BRS during CT are probably due to similar sympathetic modulation in both trainings.

Six-minute walk test and heart rate variability: lack of association in advanced stages of heart failure.

PubMed

Woo, M A; Moser, D K; Stevenson, L W; Stevenson, W G

1997-09-01

The 6-minute walk and heart rate variability have been used to assess mortality risk in patients with heart failure, but their relationship to each other and their usefulness for predicting mortality at 1 year are unknown. To assess the relationships between the 6-minute walk test, heart rate variability, and 1-year mortality. A sample of 113 patients in advanced stages of heart failure (New York Heart Association Functional Class III-IV, left ventricular ejection < 0.25) were studied. All 6-minute walks took place in an enclosed, level, measured corridor and were supervised by the same nurse. Heart rate variability was measured by using (1) a standard-deviation method and (2) Poincaré plots. Data on RR intervals obtained by using 24-hour Holter monitoring were analyzed. Survival was determined at 1 year after the Holter recording. The results showed no significant associations between the results of the 6-minute walk and the two measures of heart rate variability. The results of the walk were related to 1-year mortality but not to the risk of sudden death. Both measures of heart rate variability had significant associations with 1-year mortality and with sudden death. However, only heart rate variability measured by using Poincaré plots was a predictor of total mortality and risk of sudden death, independent of left ventricular ejection fraction, serum levels of sodium, results of the 6-minute walk test, and the standard-deviation measure of heart rate variability. Results of the 6-minute walk have poor association with mortality and the two measures of heart rate variability in patients with advanced-stage heart failure and a low ejection fraction. Further studies are needed to determine the optimal clinical usefulness of the 6-minute walk and heart rate variability in patients with advanced-stage heart failure.

Variability in heart rate recovery measurements over 1 year in healthy, middle-aged adults.

PubMed

Mellis, M G; Ingle, L; Carroll, S

2014-02-01

This study assessed the longer-term (12-month) variability in post-exercise heart rate recovery following a submaximal exercise test. Longitudinal data was analysed for 97 healthy middle-aged adults (74 male, 23 female) from 2 occasions, 12 months apart. Participants were retrospectively selected if they had stable physical activity habits, submaximal treadmill fitness and anthropometric measurements between the 2 assessment visits. A submaximal Bruce treadmill test was performed to at least 85% age-predicted maximum heart rate. Absolute heart rate and Δ heart rate recovery (change from peak exercise heart rate) were recorded for 1 and 2 min post-exercise in an immediate supine position. Heart rate recovery at both time-points was shown to be reliable with intra-class correlation coefficient values ≥ 0.714. Absolute heart rate 1-min post-exercise showed the strongest agreement between repeat tests (r = 0.867, P < 0.001). Lower coefficient of variation (≤ 10.2%) and narrower limits of agreement were found for actual heart rate values rather than Δ heart rate recovery, and for 1-min rather than 2-min post-exercise recovery time points. Log-transformed values generated better variability with acceptable coefficient of variation for all measures (2.2-10%). Overall, 1 min post-exercise heart rate recovery data had least variability over the 12-month period in apparently healthy middle-aged adults. © Georg Thieme Verlag KG Stuttgart · New York.

Elevated resting heart rate is associated with dyslipidemia in middle-aged and elderly Chinese.

PubMed

Sun, Ji Chao; Huang, Xiao Lin; Deng, Xin Ru; Lv, Xiao Fei; Lu, Jie Li; Chen, Yu Hong; Bi, Yu Fang; Wang, Wei Qing; Xu, Min; Ning, Guang

2014-08-01

To study the relationship between resting heart rate and blood lipid level. A total of 9 415 subjects aged ⋝ 40 years were included in the present study. Their resting heart rate was monitored and their serum levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were measured to define dyslipidemia according to the 2007 Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. The subjects were divided into group A with their resting heart rate <70 beats/min, group B with their resting heart rate =70-79 beats/min, group C with their resting heart rate =80-89 beats/min, and group D with their resting heart rate ⋝ 90 beats/min. High TG, TC, and LDL-C were presented across the resting heart rate (Ptrend <0.01). Multiple logistic regression analysis revealed that the risk of high TG and TC was higher in subjects with their resting heart rate ⋝ 90 beats/min than in those with their resting heart rate <70 beats/min (OR=1.42; 95% CI: 1.16-1.74 and OR=1.33; 95% CI: 1.09-1.64, respectively). Elevated resting heart rate is associated with high TG and TC in middle-aged and elderly Chinese subjects. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor

PubMed Central

Salehizadeh, Seyed M. A.; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H.

2015-01-01

Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be accurately captured using the algorithm where the mean Pearson’s correlation coefficient between the power spectral densities of the reference and the reconstructed heart rate time series was found to be 0.98. These results show that the SpaMA method has a potential for PPG-based HR monitoring in wearable devices for fitness tracking and health monitoring during intense physical activities. PMID:26703618

A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor.

PubMed

Salehizadeh, Seyed M A; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H

2015-12-23

Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be accurately captured using the algorithm where the mean Pearson's correlation coefficient between the power spectral densities of the reference and the reconstructed heart rate time series was found to be 0.98. These results show that the SpaMA method has a potential for PPG-based HR monitoring in wearable devices for fitness tracking and health monitoring during intense physical activities.

A portable personal cooling system for mine rescue operations

NASA Technical Reports Server (NTRS)

Webbon, B.; Williams, B.; Kirk, P.; Elkins, W.; Stein, R.

1977-01-01

Design of a portable personal cooling system to reduce physiological stress in high-temperature, high-humidity conditions is discussed. The system, based on technology used in the thermal controls of space suits, employs a combination of head and thoracic insulation and cooling through a heat sink unit. Average metabolic rates, heart rates, rectal temperature increase and sweat loss were monitored for test subjects wearing various configurations of the cooling system, as well as for a control group. The various arrangements of the cooling garment were found to provide significant physiological benefits; however, increases in heat transfer rate of the cooling unit and more effective insulation are suggested to improve the system's function.

Do infants find snakes aversive? Infants' physiological responses to "fear-relevant" stimuli.

PubMed

Thrasher, Cat; LoBue, Vanessa

2016-02-01

In the current research, we sought to measure infants' physiological responses to snakes-one of the world's most widely feared stimuli-to examine whether they find snakes aversive or merely attention grabbing. Using a similar method to DeLoache and LoBue (Developmental Science, 2009, Vol. 12, pp. 201-207), 6- to 9-month-olds watched a series of multimodal (both auditory and visual) stimuli: a video of a snake (fear-relevant) or an elephant (non-fear-relevant) paired with either a fearful or happy auditory track. We measured physiological responses to the pairs of stimuli, including startle magnitude, latency to startle, and heart rate. Results suggest that snakes capture infants' attention; infants showed the fastest startle responses and lowest average heart rate to the snakes, especially when paired with a fearful voice. Unexpectedly, they also showed significantly reduced startle magnitude during this same snake video plus fearful voice combination. The results are discussed with respect to theoretical perspectives on fear acquisition. Copyright © 2015 Elsevier Inc. All rights reserved.

Reproducibility of skeletal muscle vasodilatation responses to Stroop mental challenge over repeated sessions.

PubMed

Hamer, Mark; Boutcher, Yati N; Park, Young; Boutcher, Stephen H

2006-08-01

Skeletal muscle blood flow responses to stress have implications for psychobiological disease pathways. An important assumption underlying psychophysiological studies relating stress reactivity with disease risk is that individuals are characterized by stable response profiles that can be reliably assessed using acute psychophysiological stress testing. We examined the reproducibility of forearm vasodilatation, blood pressure, and cardiac responses to a 2 min Stroop mental challenge over two repeated stress sessions that were on average 3.6 months apart. Participants were 21 healthy men and women (aged 21.8+/-3.7 years). Vasodilatation, blood pressure and heart rate responses displayed no habituation between sessions, although there was significantly greater cardiac parasympathetic involvement during the second testing session. Significant test-retest correlations between the sessions were observed for both forearm blood flow and heart rate reactivity. These findings demonstrate skeletal muscle vasodilatation responses to repeated stress are robust, so may be a useful psychophysiological indicator in studies of stress reactivity and disease risk.

Cardiac reserve during weightlessness simulation and shuttle flight

NASA Technical Reports Server (NTRS)

Goldberger, A. L.

1985-01-01

Bedrest deconditioning is suspected to reduce cardiac function. However, quantitation of subtle decreases in cardiac reserve may be difficult. Normal subjects show considerable variability in heart rate response, reflected by a relatively broadband interbeat interval power spectrum. We hypothesized that the deconditioning effects of bedrest would induce narrowing of this spectrum, reflecting a reduction in the autonomically-modulated variability in heart rate. Ten aerobically conditioned men (average 35-50 years) underwent orthostatic tolerance testing with lower body negative pressure pre-bedrest and after 10 days of bedrest, while on placebo and after intravenous atropine. Spectra were derived by Fourier analysis of 128 interbeat interval data sets from subjects with sufficient numbers of beats during matched periods of the protocol. Data suggest that atropine unmasks the deconditioning effect of bedrest in athletic men, evidenced by a reduction in interbeat interval spectral power compared with placebo. Spectral analysis offers a new means of quantitating the effects of bedrest deconditioning and autonomic perturbations on cardiac dynamics.

A prepared speech in front of a pre-recorded audience: subjective, physiological, and neuroendocrine responses to the Leiden Public Speaking Task.

PubMed

Westenberg, P Michiel; Bokhorst, Caroline L; Miers, Anne C; Sumter, Sindy R; Kallen, Victor L; van Pelt, Johannes; Blöte, Anke W

2009-10-01

This study describes a new public speaking protocol for youth. The main question asked whether a speech prepared at home and given in front of a pre-recorded audience creates a condition of social-evaluative threat. Findings showed that, on average, this task elicits a moderate stress response in a community sample of 83 12- to 15-year-old adolescents. During the speech, participants reported feeling more nervous and having higher heart rate and sweatiness of the hands than at baseline or recovery. Likewise, physiological (heart rate and skin conductance) and neuroendocrine (cortisol) activity were higher during the speech than at baseline or recovery. Additionally, an anticipation effect was observed: baseline levels were higher than recovery levels for most variables. Taking the anticipation and speech response together, a substantial cortisol response was observed for 55% of participants. The findings indicate that the Leiden Public Speaking Task might be particularly suited to investigate individual differences in sensitivity to social-evaluative situations.

Recurrence quantification analysis of heart rate variability and respiratory flow series in patients on weaning trials.

PubMed

Arcentales, Andrés; Giraldo, Beatriz F; Caminal, Pere; Benito, Salvador; Voss, Andreas

2011-01-01

Autonomic nervous system regulates the behavior of cardiac and respiratory systems. Its assessment during the ventilator weaning can provide information about physio-pathological imbalances. This work proposes a non linear analysis of the complexity of the heart rate variability (HRV) and breathing duration (T(Tot)) applying recurrence plot (RP) and their interaction joint recurrence plot (JRP). A total of 131 patients on weaning trials from mechanical ventilation were analyzed: 92 patients with successful weaning (group S) and 39 patients that failed to maintain spontaneous breathing (group F). The results show that parameters as determinism (DET), average diagonal line length (L), and entropy (ENTR), are statistically significant with RP for T(Tot) series, but not with HRV. When comparing the groups with JRP, all parameters have been relevant. In all cases, mean values of recurrence quantification analysis are higher in the group S than in the group F. The main differences between groups were found on the diagonal and vertical structures of the joint recurrence plot.

Effects of Three Months Fingolimod Therapy on Heart Rate.

PubMed

Simula, Sakari; Laitinen, Tomi; Laitinen, Tiina M; Tarkiainen, Tuula; Hartikainen, Juha E K; Hartikainen, Päivi

2015-12-01

Fingolimod is a novel disease-modifying drug for relapsing-remitting multiple sclerosis (RRMS). Fingolimod initiation associates with a decrease in heart rate (HR). However, the long-term effects of fingolimod on HR are not known. The aim of this study was prospectively investigate the effect of 3-month fingolimod therapy on HR. Twenty-seven RRMS patients underwent 24-h ambulatory electrocardiogram recording 20 ± 16 days before (baseline) and at the day of fingolimod initiation (1 day). Twenty-four patients completed 3 months follow-up (3 months). The average HR over 24-h and the average HR for daytime and nighttime were assessed at baseline, 1 day and 3 months. Fingolimod initiation resulted in slowing of HR from 82 ± 11 1/min at baseline to 63 ± 9.5 1/min at 5 h after the initiation of the therapy. The average HR during 24-h was lower at 1d (66 ± 7.8 1/min;p < 0.001) and also at 3 months (69 ± 8.3 1/min;p < 0.001) as compared to baseline (74 ± 10 1/min). The average daytime HR at 1 day (68 ± 8.4 1/min) was lower as compared to baseline (78 ± 11 1/min, p < 0.001), whereas no difference was found between the average daytime HR at baseline and at 3 months (79 ± 10 1/min). The average nighttime HR at 1 day (59 ± 8.8 1/min;p < 0.001) and at 3 months (60 ± 9.2 1/min;p < 0.05) both were lower than at baseline (64 ± 9.9 1/min). In conclusion, fingolimod resulted in HR decrease reaching the nadir at 5 h after the first dose. HR remained lower after 3 months fingolimod treatment as compared to baseline. Particularly, HR at daytime recovered whereas the nighttime HR showed not recovery as compared to the day of fingolimod initiation.

Heart Rate Response in Spectators of the Montreal Canadiens Hockey Team.

PubMed

Khairy, Leia T; Barin, Roxana; Demonière, Fabrice; Villemaire, Christine; Billo, Marie-Josée; Tardif, Jean-Claude; Macle, Laurent; Khairy, Paul

2017-12-01

To our knowledge, heart rate responses have not previously been assessed in hockey fans. We quantified heart rate increases in spectators of the Montreal Canadiens, compared televised with live games, explored features associated with peak heart rates, and assessed whether increases correlate with a fan passion score. Healthy adults were enrolled, with half attending live games and half viewing televised games. All subjects completed questionnaires and had continuous Holter monitoring. Intensity of the physical stress response was defined according to previously published heart rate index thresholds as mild (< 1.33), moderate (1.33-1.83), or vigorous (> 1.83). In 20 participants, 35% women, age 46 ± 10 years, the heart rate increased by a median of 92% during the hockey game, from 60 (interquartile range, 54-65) beats per minute at rest to 114 (interquartile range, 103-129) beats per minute (P < 0.001). The heart rate increased by 110% vs 75% during live vs televised games (P < 0.001). Heart rate index (2.16 ± 0.27 vs 1.73 ± 0.15; P < 0.001) and percent maximum predicted heart rate attained (75% ± 8% vs 58% ± 7%; P < 0.001) were significantly higher during live vs televised games. Number of premature beats was nonsignificantly higher during live games (5 vs 1; P = 0.181). The fan passion score was not predictive of the heart rate response (P = 0.753). Peak heart rates most commonly occurred during overtime (40%) and scoring opportunities for (25%) and against (15%). It is exciting to watch the Montreal Canadiens! Viewing a live hockey game is associated with a heart rate response equivalent to vigorous physical stress and a televised game to moderate physical stress. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Conventional heart rate variability analysis of ambulatory electrocardiographic recordings fails to predict imminent ventricular fibrillation

NASA Technical Reports Server (NTRS)

Vybiral, T.; Glaeser, D. H.; Goldberger, A. L.; Rigney, D. R.; Hess, K. R.; Mietus, J.; Skinner, J. E.; Francis, M.; Pratt, C. M.

1993-01-01

OBJECTIVES. The purpose of this report was to study heart rate variability in Holter recordings of patients who experienced ventricular fibrillation during the recording. BACKGROUND. Decreased heart rate variability is recognized as a long-term predictor of overall and arrhythmic death after myocardial infarction. It was therefore postulated that heart rate variability would be lowest when measured immediately before ventricular fibrillation. METHODS. Conventional indexes of heart rate variability were calculated from Holter recordings of 24 patients with structural heart disease who had ventricular fibrillation during monitoring. The control group consisted of 19 patients with coronary artery disease, of comparable age and left ventricular ejection fraction, who had nonsustained ventricular tachycardia but no ventricular fibrillation. RESULTS. Heart rate variability did not differ between the two groups, and no consistent trends in heart rate variability were observed before ventricular fibrillation occurred. CONCLUSIONS. Although conventional heart rate variability is an independent long-term predictor of adverse outcome after myocardial infarction, its clinical utility as a short-term predictor of life-threatening arrhythmias remains to be elucidated.

Association between heart rate variability and manual pulse rate.

PubMed

Hart, John

2013-09-01

One model for neurological assessment in chiropractic pertains to autonomic variability, tested commonly with heart rate variability (HRV). Since HRV may not be convenient to use on all patient visits, more user-friendly methods may help fill-in the gaps. Accordingly, this study tests the association between manual pulse rate and heart rate variability. The manual rates were also compared to the heart rate derived from HRV. Forty-eight chiropractic students were examined with heart rate variability (SDNN and mean heart rate) and two manual radial pulse rate measurements. Inclusion criteria consisted of participants being chiropractic students. Exclusion criteria for 46 of the participants consisted of a body mass index being greater than 30, age greater than 35, and history of: a) dizziness upon standing, b) treatment of psychiatric disorders, and c) diabetes. No exclusion criteria were applied to the remaining two participants who were also convenience sample volunteers. Linear associations between the manual pulse rate methods and the two heart rate variability measures (SDNN and mean heart) were tested with Pearson's correlation and simple linear regression. Moderate strength inverse (expected) correlations were observed between both manual pulse rate methods and SDNN (r = -0.640, 95% CI -0.781, -0.435; r = -0.632, 95% CI -0.776, -0.425). Strong direct (expected) relationships were observed between the manual pulse rate methods and heart rate derived from HRV technology (r = 0.934, 95% CI 0.885, 0.962; r = 0.941, 95% CI 0.897, 0.966). Manual pulse rates may be a useful option for assessing autonomic variability. Furthermore, this study showed a strong relationship between manual pulse rates and heart rate derived from HRV technology.

Blood Pressure vs. Heart Rate

MedlinePlus

... Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 Understanding the difference ... your blood moving through your blood vessels, your heart rate is the number of times your heart beats ...

The predictive value of resting heart rate following osmotherapy in brain injury: back to basics

PubMed Central

2012-01-01

Background The importance of resting heart rate as a prognostic factor was described in several studies. An elevated heart rate is an independent risk factor for adverse cardiovascular events and total mortality in patients with coronary artery disease, chronic heart failure, and the general population. Also heart rate is elevated in the Multi Organ Dysfunction Syndrome (MODS) and the mortality due to MODS is highly correlated with inadequate sinus tachycardia. To evaluate the value of resting heart rate in predicting mortality in patients with traumatic brain injury along scoring systems like Acute Physiology and Chronic Health Evaluation(APACHE II), Sequential Organ Failure Assessment (SOFA) and Glasgow Coma Score (GCS). Method By analyzing data which was collected from an open labeled randomized clinical trial that compared the different means of osmotherapy (mannitol vs bolus or infusion hypertonic saline), heart rate, GCS, APACHE II and SOFA score were measured at baseline and daily for 7 days up to 60 days and the relationship between elevated heart rate and mortality during the first 7 days and 60th day were assessed. Results After adjustments for confounding factors, although there was no difference in mean heart rate between either groups of alive and expired patients, however, we have found a relative correlation between 60th day mortality rate and resting heart rate (P=0.07). Conclusion Heart rate can be a prognostic factor for estimating mortality rate in brain injury patients along with APACHE II and SOFA scores in patients with brain injury. PMID:23351393

Heart rates increase after hatching in two species of natricine snakes

PubMed Central

Aubret, Fabien

2013-01-01

Experimental studies have shown heart rates to decrease from embryo to hatchling stage in turtles, remain steady in skinks, and increase in birds. However, no snake species has been studied in this regard. I recorded heart rate evolution trajectories from embryo to juvenile stage in 78 eggs from two species of European Natricine snakes. Unexpectedly, snakes behaved more like birds than turtles or lizards: heart rates increased after hatching in both N. maura and N. natrix, respectively by 43.92 ± 22.84% and 35.92 ± 24.52%. Heart rate shift was not related to an abrupt elevation of metabolism per se (snakes that increased their heart rates the most sharply grew the least after birth), but rather due to a number of smaller eggs that experienced lower than normal heart rates throughout the incubation and recovered a normal heart rate post-birth. This finding is discussed in the light of hatching synchrony benefits. PMID:24287712

What You Don't Know: Improving Family Health History Knowledge among Multigenerational Families of Mexican Origin.

PubMed

Goergen, Andrea F; Ashida, Sato; Skapinsky, Kaley; de Heer, Hendrik D; Wilkinson, Anna V; Koehly, Laura M

2016-01-01

This study investigated diabetes and heart disease family health history (FHH) knowledge and changes after providing personalized disease risk feedback. A total of 497 adults from 162 families of Mexican origin were randomized by household to conditions based on feedback recipient and content. Each provided personal and relatives' diabetes and heart disease diagnoses and received feedback materials following baseline assessment. Multivariate models were fitted to identify factors associated with the rate of 'don't know' FHH responses. At baseline, US nativity was associated with a higher 'don't know' response rate (p = 0.002). Though confounded by country of birth, younger age showed a trend toward higher 'don't know' response rates. Overall, average 'don't know' response rates dropped from 20 to 15% following receipt of feedback (p < 0.001). An intervention effect was noted, as 'don't know' response rates decreased more in households where one family member (vs. all) received supplementary risk assessments (without behavioral recommendations; p = 0.011). Limited FHH knowledge was noted among those born in the US and younger participants, representing a key population to reach with intervention efforts. The intervention effect suggests that 'less is more', indicating the potential for too much information to limit health education program effectiveness. © 2016 S. Karger AG, Basel.

Discovery of novel heart rate-associated loci using the Exome Chip

PubMed Central

van den Berg, Marten E.; Warren, Helen R.; Cabrera, Claudia P.; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A.; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J.; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A.; Müller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V.; Lyytikäinen, Leo-Pekka; Hall, Leanne M.; van Setten, Jessica; Trompet, Stella; Prins, Bram P.; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A.; Silva, Claudia T.; Alonso, Alvaro; Bis, Joshua C.; de Boer, Rudolf; de Haan, Hugoline G.; de Mutsert, Renée; Dedoussis, George; Dominiczak, Anna F.; Doney, Alex S. F.; Ellinor, Patrick T.; Eppinga, Ruben N.; Felix, Stephan B.; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B.; Heckbert, Susan R.; Huang, Paul L.; Hwang, Shih-Jen; Kähönen, Mika; Kanters, Jørgen K.; Kolcic, Ivana; Launer, Lenore J.; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; Macfarlane, Peter W.; Mangino, Massimo; Morris, Andrew D.; Mulas, Antonella; Murray, Alison D.; Nelson, Christopher P.; Orrú, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J.; Poulter, Neil; Psaty, Bruce M.; Qi, Lihong; Raitakari, Olli T.; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F.; Soliman, Elsayed Z.; Spector, Timothy D.; Stanton, Alice V.; Stirrups, Kathleen E.; Taylor, Kent D.; Tobin, Martin D.; Uitterlinden, André; Vaartjes, Ilonca; Hoes, Arno W.; van der Meer, Peter; Völker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; van Duijn, Cornelia M.; Zeggini, Eleftheria; Jukema, J. Wouter; Asselbergs, Folkert W.; Samani, Nilesh J.; Lehtimäki, Terho; Gudnason, Vilmundur; Wilson, James; Lubitz, Steven A.; Kääb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J.; Palmer, Colin N. A.; Sanna, Serena; Mook-Kanamori, Dennis O.; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I.; Dörr, Marcus; O'Donnell, Chris J.; Hayward, Caroline; Arking, Dan E.; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H.; Munroe, Patricia B.

2017-01-01

Abstract Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to discover new genetic loci associated with heart rate from Exome Chip meta-analyses. Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods. We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) and fetal muscle samples by including our novel variants. Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies. PMID:28379579

Discovery of novel heart rate-associated loci using the Exome Chip.

PubMed

van den Berg, Marten E; Warren, Helen R; Cabrera, Claudia P; Verweij, Niek; Mifsud, Borbala; Haessler, Jeffrey; Bihlmeyer, Nathan A; Fu, Yi-Ping; Weiss, Stefan; Lin, Henry J; Grarup, Niels; Li-Gao, Ruifang; Pistis, Giorgio; Shah, Nabi; Brody, Jennifer A; Müller-Nurasyid, Martina; Lin, Honghuang; Mei, Hao; Smith, Albert V; Lyytikäinen, Leo-Pekka; Hall, Leanne M; van Setten, Jessica; Trompet, Stella; Prins, Bram P; Isaacs, Aaron; Radmanesh, Farid; Marten, Jonathan; Entwistle, Aiman; Kors, Jan A; Silva, Claudia T; Alonso, Alvaro; Bis, Joshua C; de Boer, Rudolf; de Haan, Hugoline G; de Mutsert, Renée; Dedoussis, George; Dominiczak, Anna F; Doney, Alex S F; Ellinor, Patrick T; Eppinga, Ruben N; Felix, Stephan B; Guo, Xiuqing; Hagemeijer, Yanick; Hansen, Torben; Harris, Tamara B; Heckbert, Susan R; Huang, Paul L; Hwang, Shih-Jen; Kähönen, Mika; Kanters, Jørgen K; Kolcic, Ivana; Launer, Lenore J; Li, Man; Yao, Jie; Linneberg, Allan; Liu, Simin; Macfarlane, Peter W; Mangino, Massimo; Morris, Andrew D; Mulas, Antonella; Murray, Alison D; Nelson, Christopher P; Orrú, Marco; Padmanabhan, Sandosh; Peters, Annette; Porteous, David J; Poulter, Neil; Psaty, Bruce M; Qi, Lihong; Raitakari, Olli T; Rivadeneira, Fernando; Roselli, Carolina; Rudan, Igor; Sattar, Naveed; Sever, Peter; Sinner, Moritz F; Soliman, Elsayed Z; Spector, Timothy D; Stanton, Alice V; Stirrups, Kathleen E; Taylor, Kent D; Tobin, Martin D; Uitterlinden, André; Vaartjes, Ilonca; Hoes, Arno W; van der Meer, Peter; Völker, Uwe; Waldenberger, Melanie; Xie, Zhijun; Zoledziewska, Magdalena; Tinker, Andrew; Polasek, Ozren; Rosand, Jonathan; Jamshidi, Yalda; van Duijn, Cornelia M; Zeggini, Eleftheria; Jukema, J Wouter; Asselbergs, Folkert W; Samani, Nilesh J; Lehtimäki, Terho; Gudnason, Vilmundur; Wilson, James; Lubitz, Steven A; Kääb, Stefan; Sotoodehnia, Nona; Caulfield, Mark J; Palmer, Colin N A; Sanna, Serena; Mook-Kanamori, Dennis O; Deloukas, Panos; Pedersen, Oluf; Rotter, Jerome I; Dörr, Marcus; O'Donnell, Chris J; Hayward, Caroline; Arking, Dan E; Kooperberg, Charles; van der Harst, Pim; Eijgelsheim, Mark; Stricker, Bruno H; Munroe, Patricia B

2017-06-15

Resting heart rate is a heritable trait, and an increase in heart rate is associated with increased mortality risk. Genome-wide association study analyses have found loci associated with resting heart rate, at the time of our study these loci explained 0.9% of the variation. This study aims to discover new genetic loci associated with heart rate from Exome Chip meta-analyses.Heart rate was measured from either elecrtrocardiograms or pulse recordings. We meta-analysed heart rate association results from 104 452 European-ancestry individuals from 30 cohorts, genotyped using the Exome Chip. Twenty-four variants were selected for follow-up in an independent dataset (UK Biobank, N = 134 251). Conditional and gene-based testing was undertaken, and variants were investigated with bioinformatics methods.We discovered five novel heart rate loci, and one new independent low-frequency non-synonymous variant in an established heart rate locus (KIAA1755). Lead variants in four of the novel loci are non-synonymous variants in the genes C10orf71, DALDR3, TESK2 and SEC31B. The variant at SEC31B is significantly associated with SEC31B expression in heart and tibial nerve tissue. Further candidate genes were detected from long-range regulatory chromatin interactions in heart tissue (SCD, SLF2 and MAPK8). We observed significant enrichment in DNase I hypersensitive sites in fetal heart and lung. Moreover, enrichment was seen for the first time in human neuronal progenitor cells (derived from embryonic stem cells) and fetal muscle samples by including our novel variants.Our findings advance the knowledge of the genetic architecture of heart rate, and indicate new candidate genes for follow-up functional studies. © The Author 2017. Published by Oxford University Press.

A real time ECG signal processing application for arrhythmia detection on portable devices

NASA Astrophysics Data System (ADS)

Georganis, A.; Doulgeraki, N.; Asvestas, P.

2017-11-01

Arrhythmia describes the disorders of normal heart rate, which, depending on the case, can even be fatal for a patient with severe history of heart disease. The purpose of this work is to develop an application for heart signal visualization, processing and analysis in Android portable devices e.g. Mobile phones, tablets, etc. The application is able to retrieve the signal initially from a file and at a later stage this signal is processed and analysed within the device so that it can be classified according to the features of the arrhythmia. In the processing and analysing stage, different algorithms are included among them the Moving Average and Pan Tompkins algorithm as well as the use of wavelets, in order to extract features and characteristics. At the final stage, testing is performed by simulating our application in real-time records, using the TCP network protocol for communicating the mobile with a simulated signal source. The classification of ECG beat to be processed is performed by neural networks.

Improvement on the auxiliary total artificial heart (ATAH) left chamber design.

PubMed

Andrade, Aron; Fonseca, Jeison; Legendre, Daniel; Nicolosi, Denys; Biscegli, Jose; Pinotti, Marcos; Ohashi, Yukio; Nosé, Yukihiko

2003-05-01

The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow. The ATAH left and right stroke volumes are 38 ml and 34 ml, respectively, giving approximately 5 L/min of cardiac output at 160 bpm. Flow visualization studies were performed in critical areas on the ATAH left chamber. A closed circuit loop was used with water and glycerin (37%) at 25 degrees C. Amberlite particles (80 mesh) were illuminated by a 1 mm planar helium-neon laser light. With left mean preload fixed at 10 mm Hg and the afterload at 100 mm Hg, the heart rate varied from 60 to 200 bpm. Two porcine valves were used on the inlet and outlet ports. The flow pattern images were obtained using a color micro-camera and a video recorder. Subsequently, these images were digitized using a PC computer. A persistent stagnant flow was detected in the left chamber inlet port. After improvement on the left chamber design, this stagnant flow disappeared.

Self-adaptive signals separation for non-contact heart rate estimation from facial video in realistic environments.

PubMed

Liu, Xuenan; Yang, Xuezhi; Jin, Jing; Li, Jiangshan

2018-06-05

Recent researches indicate that facial epidermis color varies with the rhythm of heat beats. It can be captured by consumer-level cameras and, astonishingly, be adopted to estimate heart rate (HR). The HR estimated remains not as precise as required in practical environment where illumination interference, facial expressions, or motion artifacts are involved, though numerous methods have been proposed in the last few years. A novel algorithm is proposed to make non-contact HR estimation technique more robust. First, the face of subject is detected and tracked to follow the head movement. The facial region then falls into several blocks, and the chrominance feature of each block is extracted to establish raw HR sub-signal. Self-adaptive signals separation (SASS) is performed to separate the noiseless HR sub-signals from raw sub-signals. On that basis, the noiseless sub-signals full of HR information are selected using weight-based scheme to establish the holistic HR signal, from which average HR is computed adopting wavelet transform and data filter. Forty subjects take part in our experiments, whose facial videos are recorded by a normal webcam with the frame rate of 30 fps under ambient lighting conditions. The average HR estimated by our method correlates strongly with ground truth measurements, as indicated in experimental results measured in static scenario with the Pearson's correlation r=0.980 and dynamic scenario with the Pearson's correlation r=0.897. Our method, compared to the newest method, decreases the error rate by 38.63% and increases the Pearson's correlation by 15.59%, indicating that our method evidently outperforms state-of-the-art non-contact HR estimation methods in realistic environments. © 2018 Institute of Physics and Engineering in Medicine.

Rocker shoe, minimalist shoe, and standard running shoe: a comparison of running economy.

PubMed

Sobhani, Sobhan; Bredeweg, Steef; Dekker, Rienk; Kluitenberg, Bas; van den Heuvel, Edwin; Hijmans, Juha; Postema, Klaas

2014-05-01

Running with rocker shoes is believed to prevent lower limb injuries. However, it is not clear how running in these shoes affects the energy expenditure. The purpose of this study was, therefore, to assess the effects of rocker shoes on running economy in comparison with standard and minimalist running shoes. Cross-over design. Eighteen endurance female runners (age=23.6 ± 3 years), who were inexperienced in running with rocker shoes and with minimalist/barefoot running, participated in this study. Oxygen consumption, carbon dioxide production, heart rate and rate of perceived exertion were measured while participants completed a 6-min sub-maximal treadmill running test for each footwear condition. The data of the last 2 min of each shoe condition were averaged for analysis. A linear mixed model was used to compare differences among three footwear conditions. Oxygen consumption during running with rocker shoes was on average 4.5% higher than with the standard shoes (p<0.001) and 5.6% higher than with the minimalist shoe (p<0.001). No significant differences were found in heart rate and rate of perceived exertion across three shoe conditions. Female runners, who are not experienced in running with the rocker shoes and minimalist shoes, show more energy expenditure during running with the rocker shoes compared with the standard and minimalist shoes. As the studied shoes were of different masses, part of the effect of increased energy expenditure with the rocker shoe is likely to be due to its larger mass as compared with standard running shoes and minimalist shoes. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Heart rate at baseline influences the effect of ivabradine on cardiovascular outcomes in chronic heart failure: analysis from the SHIFT study.

PubMed

Böhm, Michael; Borer, Jeffrey; Ford, Ian; Gonzalez-Juanatey, Jose R; Komajda, Michel; Lopez-Sendon, Jose; Reil, Jan-Christian; Swedberg, Karl; Tavazzi, Luigi

2013-01-01

We analysed the effect of ivabradine on outcomes in heart failure (HF) patients on recommended background therapies with heart rates ≥75 bpm and <75 bpm in the SHIFT trial. A cut-off value of ≥75 bpm was chosen by the EMEA for approval for the use of ivabradine in chronic heart failure. The SHIFT population was divided by baseline heart rate ≥75 or <75 bpm. The effect of ivabradine was analysed for primary composite endpoint (cardiovascular death or HF hospitalization) and other endpoints. In the ≥75 bpm group, ivabradine reduced primary endpoint (HR 0.76, 95 % CI 0.68-0.85, P < 0.0001), all-cause mortality (HR 0.83, 95 % CI, 0.72-0.96, P = 0.0109), cardiovascular mortality (HR 0.83, 95 % CI, (0.71-0.97, P = 0.0166), HF death (HR 0.61, 95 % CI, 0.46-0.81, P < 0.0006), and HF hospitalization (HR 0.70, 95 % CI, 0.61-0.80, P < 0.0001). Risk reduction depended on heart rate after 28 days, with the best protection for heart rates <60 bpm or reductions >10 bpm. None of the endpoints was significantly reduced in the <75 bpm group, though there were trends for risk reductions in HF death and hospitalization for heart rate <60 bpm and reductions >10 bpm. Ivabradine was tolerated similarly in both groups. The effect of ivabradine on outcomes is greater in patients with heart rate ≥75 bpm with heart rates achieved <60 bpm or heart rate reductions >10 bpm predicting best risk reduction. Our findings emphasize the importance of identification of high-risk HF patients by high heart rates and their treatment with heart rate-lowering drugs such as ivabradine.

Heart Rate Assessment Immediately after Birth.

PubMed

Phillipos, Emily; Solevåg, Anne Lee; Pichler, Gerhard; Aziz, Khalid; van Os, Sylvia; O'Reilly, Megan; Cheung, Po-Yin; Schmölzer, Georg M

2016-01-01

Heart rate assessment immediately after birth in newborn infants is critical to the correct guidance of resuscitation efforts. There are disagreements as to the best method to measure heart rate. The aim of this study was to assess different methods of heart rate assessment in newborn infants at birth to determine the fastest and most accurate method. PubMed, EMBASE and Google Scholar were systematically searched using the following terms: 'infant', 'heart rate', 'monitoring', 'delivery room', 'resuscitation', 'stethoscope', 'auscultation', 'palpation', 'pulse oximetry', 'electrocardiogram', 'Doppler ultrasound', 'photoplethysmography' and 'wearable sensors'. Eighteen studies were identified that described various methods of heart rate assessment in newborn infants immediately after birth. Studies examining auscultation, palpation, pulse oximetry, electrocardiography and Doppler ultrasound as ways to measure heart rate were included. Heart rate measurements by pulse oximetry are superior to auscultation and palpation, but there is contradictory evidence about its accuracy depending on whether the sensor is connected to the infant or the oximeter first. Several studies indicate that electrocardiogram provides a reliable heart rate faster than pulse oximetry. Doppler ultrasound shows potential for clinical use, however future evidence is needed to support this conclusion. Heart rate assessment is important and there are many measurement methods. The accuracy of routinely applied methods varies, with palpation and auscultation being the least accurate and electrocardiogram being the most accurate. More research is needed on Doppler ultrasound before its clinical use. © 2015 S. Karger AG, Basel.

Duration of daily TV/screen watching with cardiovascular, respiratory, mental and psychiatric health: Scottish Health Survey, 2012-2013.

PubMed

Shiue, Ivy

2015-01-01

The link of duration of TV and/or screen watching and chronic health conditions by subtypes is unclear. Therefore, the relationship between TV and/or screen watching hours and cardiovascular, respiratory, mental and psychiatric health and well-being (happiness) was assessed in an independent population-based survey to identify correlations of various hours with health conditions. Data was retrieved from the Scottish Health Survey, 2012-2013. Information on demographics, lifestyle factors, self-reported health conditions and TV and/or screen watching duration in both Scottish adults and children was collected by annual household interviews. Chi-square test and survey weighted logistic and multi-nominal modelling were performed. 5527 (57.0%) Scottish adults aged 16-99 watched TV and/or screen daily for 3 + h on average. There was a trend toward more hypertension, angina, stroke, diabetes, chronic obstructive pulmonary disease and poor self-rated health and mental health. Reporting watching TV and/or screen for 4 + h, for 5 + h and for 8 + h was associated with higher rates of heart attack, heart murmur or other heart troubles and abnormal heart rhythms, respectively. 414 (20.7%) Scottish children aged 4-12 watched TV and/or screen for 3h or more. They tended to have poor self-rated health and life difficulties perceived as emotional and behavioural problems. There were associations between various hours of TV and/or screen watching (3+h) and poor health observed both in Scottish adults and children. Future educational and public health programmes minimising TV and/or screen watching in order to protect cardiovascular, respiratory, mental and psychiatric health might be considered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparison of dexmedetomidine and chloral hydrate sedation for transthoracic echocardiography in infants and toddlers: a randomized clinical trial.

PubMed

Miller, Jeff; Xue, Bin; Hossain, Md; Zhang, Ma-Zhong; Loepke, Andreas; Kurth, Dean

2016-03-01

Procedural sedation using chloral hydrate is used in many institutions to improve the quality of transthoracic echocardiograms (TTE) in infants and young children. Chloral hydrate has limited availability in some countries, creating the need for alternative effective sedatives. The aim of our study was to compare the effectiveness of two doses of intranasal dexmedetomidine vs oral chloral hydrate sedation for transthoracic echocardiography. This is a randomized, prospective study of 150 children under the age of 3 years with known or suspected congenital heart disease scheduled for transthoracic echocardiography with sedation. Group CH received oral chloral hydrate 70 mg · kg(-1), group DEX2 received 2 μg · kg(-1) intranasal dexmedetomidine, and group DEX3 received 3 μg · kg(-1) intranasal dexmedetomidine. Acceptance of drug administration, sedation onset and duration, heart rate, and oxygen saturation, sonographer and parent satisfaction were recorded. All patients were successfully sedated for TTE. A second sedative dose (rescue) for failed single-dose sedation was required for 4% of patients after CH, none of the patients after DEX2, and 4% of patients after DEX3. Patients in group CH had an average heart rate decline of 22% during sedation, while group DEX2 decreased 27%, and group DEX3 23% (P = 0.2180). Mean time from administration of the sedative to final patient discharge was 96 min after CH, 83 min after DEX2, and 94 min after DEX3 (P = 0.1826). Intranasal dexmedetomidine 2 and 3 μg · kg(-1) were found to be as effective for TTE sedation as oral chloral hydrate with similar sedation onset and recovery time and heart rate changes in this study population. © 2015 John Wiley & Sons Ltd.

A tool for assessment of heart failure prescribing quality: A systematic review and meta-analysis.

PubMed

El Hadidi, Seif; Darweesh, Ebtissam; Byrne, Stephen; Bermingham, Margaret

2018-04-16

Heart failure (HF) guidelines aim to standardise patient care. Internationally, prescribing practice in HF may deviate from guidelines and so a standardised tool is required to assess prescribing quality. A systematic review and meta-analysis were performed to identify a quantitative tool for measuring adherence to HF guidelines and its clinical implications. Eleven electronic databases were searched to include studies reporting a comprehensive tool for measuring adherence to prescribing guidelines in HF patients aged ≥18 years. Qualitative studies or studies measuring prescription rates alone were excluded. Study quality was assessed using the Good ReseArch for Comparative Effectiveness Checklist. In total, 2455 studies were identified. Sixteen eligible full-text articles were included (n = 14 354 patients, mean age 69 ± 8 y). The Guideline Adherence Index (GAI), and its modified versions, was the most frequently cited tool (n = 13). Other tools identified were the Individualised Reconciled Evidence Recommendations, the Composite Heart Failure Performance, and the Heart Failure Scale. The meta-analysis included the GAI studies of good to high quality. The average GAI-3 was 62%. Compared to low GAI, high GAI patients had lower mortality rate (7.6% vs 33.9%) and lower rehospitalisation rates (23.5% vs 24.5%); both P ≤ .05. High GAI was associated with reduced risk of mortality (hazard ratio = 0.29, 95% confidence interval, 0.06-0.51) and rehospitalisation (hazard ratio = 0.64, 95% confidence interval, 0.41-1.00). No tool was used to improve prescribing quality. The GAI is the most frequently used tool to assess guideline adherence in HF. High GAI is associated with improved HF outcomes. Copyright © 2018 John Wiley & Sons, Ltd.

Heart rate changes during electroconvulsive therapy

PubMed Central

2013-01-01

Background This observational study documented heart rate over the entire course of electrically induced seizures and aimed to evaluate the effects of stimulus electrode placement, patients' age, stimulus dose, and additional predictors. Method In 119 consecutive patients with 64 right unilateral (RUL) and 55 bifrontal (BF) electroconvulsive treatments, heart rate graphs based on beat-to-beat measurements were plotted up to durations of 130 s. Results In RUL stimulation, the initial drop in heart rate lasted for 12.5 ± 2.6 s (mean ± standard deviation). This depended on stimulus train duration, age, and baseline heart rate. In seizures induced with BF electrode placement, a sympathetic response was observed within the first few seconds of the stimulation phase (median 3.5 s). This was also the case with subconvulsive stimulations. The mean peak heart rate in all 119 treatments amounted to 135 ± 20 bpm and depended on baseline heart rate and seizure duration; electrode placement, charge dose, and age were insignificant in regression analysis. A marked decline in heart rate in connection with seizure cessation occurred in 71% of treatments. Conclusions A significant independent effect of stimulus electrode positioning on cardiac action was evident only in the initial phase of the seizures. Electrical stimulation rather than the seizure causes the initial heart rate increase in BF treatments. The data reveal no rationale for setting the stimulus doses as a function of intraictal peak heart rates (‘benchmark method’). The marked decline in heart rate at the end of most seizures is probably mediated by a baroreceptor reflex. PMID:23764036

Field test of a paradigm: hysteresis of heart rate in thermoregulation by a free-ranging lizard (Pogona barbata).

PubMed Central

Grigg, G C; Seebacher, F

1999-01-01

The discovery that changes in heart rate and blood flow allow some reptiles to heat faster than they cool has become a central paradigm in our understanding of reptilian thermoregulation. However, this hysteresis in heart rate has been demonstrated only in simplistic laboratory heating and cooling trials, leaving its functional significance in free-ranging animals unproven. To test the validity of this paradigm, we measured heart rate and body temperature (Tb) in undisturbed, free-ranging bearded dragons (Pogona barbata), the species in which this phenomenon was first described. Our field data confirmed the paradigm and we found that heart rate during heating usually exceeded heart rate during cooling at any Tb. Importantly, however, we discovered that heart rate was proportionally faster in cool lizards whose Tb was still well below the 'preferred Tb range' compared to lizards whose Tb was already close to it. Similarly, heart rate during cooling was proportionally slower the warmer the lizard and the greater its cooling potential compared to lizards whose Tb was already near minimum operative temperature. Further, we predicted that, if heart rate hysteresis has functional significance, a 'reverse hysteresis' pattern should be observable when lizards risked overheating. This was indeed the case and, during heating on those occasions when Tb reached very high levels (> 40 degrees C), heart rate was significantly lower than heart rate during the immediately following cooling phase. These results demonstrate that physiological control of thermoregulation in reptiles is more complex than has been previously recognized. PMID:10418165

Dose to heart substructures is associated with non-cancer death after SBRT in stage I-II NSCLC patients.

PubMed

Stam, Barbara; Peulen, Heike; Guckenberger, Matthias; Mantel, Frederick; Hope, Andrew; Werner-Wasik, Maria; Belderbos, Jose; Grills, Inga; O'Connell, Nicolette; Sonke, Jan-Jakob

2017-06-01

To investigate potential associations between dose to heart (sub)structures and non-cancer death, in early stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiation therapy (SBRT). 803 patients with early stage NSCLC received SBRT with predominant schedules of 3×18Gy (59%) or 4×12Gy (19%). All patients were registered to an average anatomy, their planned dose deformed accordingly, and dosimetric parameters for heart substructures were obtained. Multivariate Cox regression and a sensitivity analysis were used to identify doses to heart substructures or heart region with a significant association with non-cancer death respectively. Median follow-up was 34.8months. Two year Kaplan-Meier overall survival rate was 67%. Of the deceased patients, 26.8% died of cancer. Multivariate analysis showed that the maximum dose on the left atrium (median 6.5Gy EQD2, range=0.009-197, HR=1.005, p-value=0.035), and the dose to 90% of the superior vena cava (median 0.59Gy EQD2, range=0.003-70, HR=1.025, p-value=0.008) were significantly associated with non-cancer death. Sensitivity analysis identified the upper region of the heart (atria+vessels) to be significantly associated with non-cancer death. Doses to mainly the upper region of the heart were significantly associated with non-cancer death. Consequently, dose sparing in particular of the upper region of the heart could potentially improve outcome, and should be further studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancing Heart-Beat-Based Security for mHealth Applications.

PubMed

Seepers, Robert M; Strydis, Christos; Sourdis, Ioannis; De Zeeuw, Chris I

2017-01-01

In heart-beat-based security, a security key is derived from the time difference between consecutive heart beats (the inter-pulse interval, IPI), which may, subsequently, be used to enable secure communication. While heart-beat-based security holds promise in mobile health (mHealth) applications, there currently exists no work that provides a detailed characterization of the delivered security in a real system. In this paper, we evaluate the strength of IPI-based security keys in the context of entity authentication. We investigate several aspects that should be considered in practice, including subjects with reduced heart-rate variability (HRV), different sensor-sampling frequencies, intersensor variability (i.e., how accurate each entity may measure heart beats) as well as average and worst-case-authentication time. Contrary to the current state of the art, our evaluation demonstrates that authentication using multiple, less-entropic keys may actually increase the key strength by reducing the effects of intersensor variability. Moreover, we find that the maximal key strength of a 60-bit key varies between 29.2 bits and only 5.7 bits, depending on the subject's HRV. To improve security, we introduce the inter-multi-pulse interval (ImPI), a novel method of extracting entropy from the heart by considering the time difference between nonconsecutive heart beats. Given the same authentication time, using the ImPI for key generation increases key strength by up to 3.4 × (+19.2 bits) for subjects with limited HRV, at the cost of an extended key-generation time of 4.8 × (+45 s).

Heart Rate and Oxygen Saturation Change Patterns During 6-min Walk Test in Subjects With Chronic Thromboembolic Pulmonary Hypertension.

PubMed

Inagaki, Takeshi; Terada, Jiro; Yahaba, Misuzu; Kawata, Naoko; Jujo, Takayuki; Nagashima, Kengo; Sakao, Seiichiro; Tanabe, Nobuhiro; Tatsumi, Koichiro

2018-05-01

The 6-min walk test (6MWT) is commonly performed to assess functional status in patients with chronic thromboembolic pulmonary hypertension. However, changes in heart rate and oxygen saturation (S pO 2 ) patterns during 6MWT in patients with chronic thromboembolic pulmonary hypertension remain unclear. Thirty-one subjects with chronic thromboembolic pulmonary hypertension were retrospectively evaluated to examine the relationships between the change in heart rate (Δheart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery during the first minute after 6MWT (HRR1), change in S pO 2 (ΔS pO 2 ), S pO 2 reduction time, and S pO 2 recovery time during 6MWT, and the severity of pulmonary hemodynamics assessed by right heart catheterization and echocardiography. Subjects with severe chronic thromboembolic pulmonary hypertension had significantly longer heart rate acceleration time (144.9 ± 63.9 s vs 96.0 ± 42.5 s, P = .033), lower Δheart rate (47.4 ± 16.9 vs 61.8 ± 13.6 beats, P = .02), and lower HRR1 (13.3 ± 9.0 beats vs 27.1 ± 9.2 beats, P < .001) compared to subjects with mild chronic thromboembolic pulmonary hypertension. Subjects with severe chronic thromboembolic pulmonary hypertension also had significantly longer S pO 2 reduction time (178.3 ± 70.3 s vs 134.3 ± 58.4 s, P = .03) and S pO 2 recovery time (107.6 ± 35.3 s vs 69.8 ± 32.7 s, P = .004) than did subjects with mild chronic thromboembolic pulmonary hypertension. Multivariate linear regression analysis showed only mean pulmonary arterial pressure independently was associated with heart rate acceleration time and slope of heart rate acceleration. Heart rate and S pO 2 change patterns during 6MWT are predominantly associated with pulmonary hemodynamics in subjects with chronic thromboembolic pulmonary hypertension. Evaluating heart rate and S pO 2 change patterns during 6MWT may serve as a safe and convenient way to follow the change in pulmonary hemodynamics. Copyright © 2018 by Daedalus Enterprises.

Role of ivabradine and heart rate lowering in chronic heart failure: guideline update.

PubMed

Chow, Sheryl L; Page, Robert Lee; Depre, Christophe

2018-06-14

This review summarizes the current management of heart failure (HF) in patients with reduced ejection fraction and the potential role of heart rate lowering agents in select populations, as recommended in the updated guidelines. Areas covered: PubMed was searched for studies that evaluated the role of heart rate lowering or ivabradine in HF management. Expert commentary: Targeting heart rate may offer benefit when added to renin-angiotensin aldosterone antagonists, and beta-blockers. Ivabradine is a heart rate lowering agent that acts on the funny current (I f ) in the sinoatrial node, thereby reducing heart rate without directly affecting cardiac contraction and relaxation. Clinical data from a phase 3 trial demonstrated that ivabradine reduced the composite endpoint of cardiovascular death or hospital admission for worsening systolic HF, while maintaining an acceptable safety profile in patients receiving standard of care therapy. These data, in addition to more recently published guidelines, suggest ivabradine as a promising new treatment option for lowering heart rate after optimizing standard therapy in select patients with chronic HF.

Heart rate-induced modifications of concentric left ventricular hypertrophy: exploration of a novel therapeutic concept.

PubMed

Klein, Franziska J; Bell, Stephen; Runte, K Elisabeth; Lobel, Robert; Ashikaga, Takamuru; Lerman, Lilach O; LeWinter, Martin M; Meyer, Markus

2016-10-01

Lowering the heart rate is considered to be beneficial in heart failure (HF) with reduced ejection fraction (HFrEF). In a dilated left ventricle (LV), pharmacological heart rate lowering is associated with a reduction in LV chamber size. In patients with HFrEF, this structural change is associated with better survival. HF with preserved ejection fraction (HFpEF) is increasingly prevalent but, so far, without any evidence-based treatment. HFpEF is typically associated with LV concentric remodeling and hypertrophy. The effects of heart rate on this structural phenotype are not known. Analogous with the benefits of a low heart rate on a dilated heart, we hypothesized that increased heart rates could lead to potentially beneficial remodeling of a concentrically hypertrophied LV. This was explored in an established porcine model of concentric LV hypertrophy and fibrosis. Our results suggest that a moderate increase in heart rate can be used to reduce wall thickness, normalize LV chamber volumes, decrease myocardial fibrosis, and improve LV compliance. Our results also indicate that the effects of heart rate can be titrated, are reversible, and do not induce HF. These findings may provide the rationale for a novel therapeutic approach for HFpEF and its antecedent disease substrate. Copyright © 2016 the American Physiological Society.

[The influence of individually fitted controlled breathing frequency on the heart rate variability indexes].

PubMed

Chuian, O M; Biriukova, O O; Ravaieva, M Iu

2010-01-01

We studied the changes in indexes of variability of heart rate and fractal neurodynamics under conditions of controlled breathing on fluctuation frequency of a spectrum of heart rate. It is shown that the controlled breathing, which frequency corresponds to a frequency of localization of the maximum peak of capacity ofa heart rate in low-frequency is a powerful mechanism of management of heart rate and change of a functional condition of an organism as a whole.

Resting Heart Rate as Predictor for Left Ventricular Dysfunction and Heart Failure: The Multi-Ethnic Study of Atherosclerosis

PubMed Central

Opdahl, Anders; Venkatesh, Bharath Ambale; Fernandes, Veronica R. S.; Wu, Colin O.; Nasir, Khurram; Choi, Eui-Young; Almeida, Andre L. C.; Rosen, Boaz; Carvalho, Benilton; Edvardsen, Thor; Bluemke, David A.; Lima, Joao A. C.

2014-01-01

OBJECTIVE To investigate the relationship between baseline resting heart rate and incidence of heart failure (HF) and global and regional left ventricular (LV) dysfunction. BACKGROUND The association of resting heart rate to HF and LV function is not well described in an asymptomatic multi-ethnic population. METHODS Participants in the Multi-Ethnic Study of Atherosclerosis had resting heart rate measured at inclusion. Incident HF was registered (n=176) during follow-up (median 7 years) in those who underwent cardiac MRI (n=5000). Changes in ejection fraction (ΔEF) and peak circumferential strain (Δεcc) were measured as markers of developing global and regional LV dysfunction in 1056 participants imaged at baseline and 5 years later. Time to HF (Cox model) and Δεcc and ΔEF (multiple linear regression models) were adjusted for demographics, traditional cardiovascular risk factors, calcium score, LV end-diastolic volume and mass in addition to resting heart rate. RESULTS Cox analysis demonstrated that for 1 bpm increase in resting heart rate there was a 4% greater adjusted relative risk for incident HF (Hazard Ratio: 1.04 (1.02, 1.06 (95% CI); P<0.001). Adjusted multiple regression models demonstrated that resting heart rate was positively associated with deteriorating εcc and decrease in EF, even in analyses when all coronary heart disease events were excluded from the model. CONCLUSION Elevated resting heart rate is associated with increased risk for incident HF in asymptomatic participants in MESA. Higher heart rate is related to development of regional and global LV dysfunction independent of subclinical atherosclerosis and coronary heart disease. PMID:24412444

Respiration and heart rate at the surface between dives in northern elephant seals.

PubMed

Le Boeuf, B J; Crocker, D E; Grayson, J; Gedamke, J; Webb, P M; Blackwell, S B; Costa, D P

2000-11-01

All underwater activities of diving mammals are constrained by the need for surface gas exchange. Our aim was to measure respiratory rate (fb) and heart rate (fh) at the surface between dives in free-ranging northern elephant seals Mirounga angustirostris. We recorded fb and fh acoustically in six translocated juveniles, 1.8-2. 4 years old, and three migrating adult males from the rookery at Año Nuevo, California, USA. To each seal, we attached a diving instrument to record the diving pattern, a satellite tag to track movements and location, a digital audio tape recorder or acoustic datalogger with an external hydrophone to record the sounds of respiration and fh at the surface, and a VHF transmitter to facilitate recovery. During surface intervals averaging 2.2+/-0.4 min, adult males breathed a mean of 32.7+/-5.4 times at a rate of 15. 3+/-1.8 breaths min(-)(1) (means +/- s.d., N=57). Mean fh at the surface was 84+/-3 beats min(-)(1). The fb of juveniles was 26 % faster than that of adult males, averaging 19.2+/-2.2 breaths min(-)(1) for a mean total of 41.2+/-5.0 breaths during surface intervals lasting 2.6+/-0.31 min. Mean fh at the surface was 106+/-3 beats min(-)(1). fb and fh did not change significantly over the course of surface intervals. Surface fb and fh were not clearly associated with levels of exertion, such as rapid horizontal transit or apparent foraging, or with measures of immediately previous or subsequent diving performance, such as diving duration, diving depth or swimming speed. Together, surface respiration rate and the duration of the preceding dive were significant predictors of surface interval duration. This implies that elephant seals minimize surface time spent loading oxygen depending on rates of oxygen uptake and previous depletion of stores.

Stroke/Death Rates Following Carotid Artery Stenting and Carotid Endarterectomy in Contemporary Administrative Dataset Registries: A Systematic Review.

PubMed

Paraskevas, K I; Kalmykov, E L; Naylor, A R

2016-01-01

Randomised trials have reported higher stroke/death rates after carotid artery stenting (CAS) versus carotid endarterectomy (CEA). Despite this, the 2011 American Heart Association (AHA) guidelines expanded CAS indications, partly because of the Carotid Revascularization Endarterectomy versus Stenting Trial, but also because of improving outcomes in industry sponsored CAS Registries. The aim of this systematic review was: (i) to compare stroke/death rates after CAS/CEA in contemporary dataset registries, (ii) to examine whether published stroke/death rates after CAS fall within AHA thresholds, and, (iii) to see if there had been a decline (over time) in procedural risk after CAS/CEA. PubMed/Medline, Embase, and Cochrane databases were systematically searched according to the recommendations of the PRISMA statement from January 1, 2008 until February 23, 2015 for administrative dataset registries reporting outcomes after both CEA and CAS. Twenty-one registries reported outcomes involving more than 1,500,000 procedures. Stroke/death after CAS was significantly higher than after CEA in 11/21 registries (52%) involving "average risk for CEA" asymptomatic patients and in 11/18 registries (61%) involving "average risk for CEA" symptomatic patients. In another five registries, CAS was associated with higher stroke/death rates than CEA for both symptomatic and asymptomatic patients, but formal statistical comparison was not reported. CAS was associated with stroke/death rates that exceeded risk thresholds recommended by the AHA in 9/21 registries (43%) involving "average risk for CEA" asymptomatic patients and in 13/18 registries (72%) involving "average risk for CEA" symptomatic patients. In 5/18 registries (28%), the procedural risk after CAS in "average risk" symptomatic patients exceeded 10%. Data from contemporary administrative dataset registries suggest that stroke/death rates following CAS remain significantly higher than after CEA and often exceed accepted AHA thresholds. There was no evidence of a sustained decline in procedural risk after CAS. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

PubMed

Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

2016-03-01

To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. © IMechE 2016.

Heart rate as an independent risk factor in patients with multiple organ dysfunction: a prospective, observational study.

PubMed

Hoke, Robert S; Müller-Werdan, Ursula; Lautenschläger, Christine; Werdan, Karl; Ebelt, Henning

2012-02-01

To study the association between baseline heart rate and outcome in patients with multiple organ dysfunction (MODS) as well as the course of heart rate over the first 4 days during MODS. Prospective observational study in 89 patients with MODS, defined as an APACHE-II score ≥20. Baseline heart rate (HR(0)) was determined over a 60-minute period at the time of MODS diagnosis. 28-day all-cause mortality was the primary endpoint of the study, a fall of the APACHE-II score by 4 points or more from day 0 to day 4 constituted the secondary endpoint. Hazard ratios for heart rate of 90 beats per minute (bpm) or greater relative to less than 90 bpm were calculated using Cox proportional hazards model and adjusted for confounding variables. Median baseline heart rate was 83 bpm in survivors and 92 bpm in non-survivors (p = 0.048). 28-day mortality was 32 and 61% in patients with HR(0) < 90 bpm and HR(0) ≥ 90 bpm, respectively. The adjusted hazard ratio for 28-day mortality was 2.30 (95% confidence interval 1.21-4.36, p = 0.001) for HR(0) ≥ 90 bpm relative to HR(0) < 90 bpm. No correlation was found between baseline heart rate and the secondary endpoint. From day 0 to day 4, heart rate remained elevated in all patients, as well as in survivors and non-survivors. A heart rate ≥90 bpm at the time of MODS diagnosis is an independent risk factor for increased 28-day mortality. As in patients with cardiovascular conditions such as coronary heart disease or chronic heart failure, heart rate might constitute a target for heart rate-lowering therapy in the narrow initial treatment window of MODS.

Association of heart rate at hospital discharge with mortality and hospitalizations in patients with heart failure.

PubMed

Habal, Marlena V; Liu, Peter P; Austin, Peter C; Ross, Heather J; Newton, Gary E; Wang, Xuesong; Tu, Jack V; Lee, Douglas S

2014-01-01

Heart failure (HF) is associated with a high burden of morbidity and mortality. Hospital discharge is an opportunity for identification of modifiable prognostic factors in the transition to chronic HF. We examined the association of discharge heart rate with 30-day and 1-year mortality and hospitalization outcomes in a cohort of 9097 patients with HF discharged from hospital. Discharge heart rate was categorized into predefined groups: 40 to 60 (n=1333), 61 to 70 (n=2170), 71 to 80 (n=2631), 81 to 90 (n=1700), and >90 bpm (n=1263). There was a significant increase in all-cause 30-day mortality with adjusted odds ratios of 1.59 (95% confidence interval [CI], 1.18-2.14; P=0.003) for discharge heart rates 81 to 90 bpm and 1.56 (95% CI, 1.13-2.16; P=0.007) for heart rates>90 bpm when compared with the reference group (heart rates, 61-70 bpm). Cardiovascular death risk at 30 days was also higher with adjusted odds ratio 1.59 (discharge heart rates, 81-90 bpm; 95% CI, 1.09-2.33; P=0.017) and 1.65 (discharge heart rates, >90 bpm; 95% CI, 1.09-2.48; P=0.017). One-year all-cause mortality (adjusted odds ratio, 1.41; 95% CI, 1.16-1.72; P<0.001) and cardiovascular death (adjusted odds ratio, 1.47; 95% CI, 1.12-1.92; P=0.005) were higher with discharge heart rates>90 bpm when compared with the reference group (heart rates, 40-60 bpm). Readmissions for HF (adjusted hazard ratio, 1.26; 95% CI, 1.04-1.54; P=0.021) and cardiovascular disease (adjusted hazard ratio, 1.29; 95% CI, 1.08-1.54; P=0.004) within 30 days were also higher with discharge heart rates>90 bpm. Higher discharge heart rates were associated with greater risk of all-cause and cardiovascular mortality≤1-year follow-up and an elevated risk of 30-day readmission for HF and cardiovascular disease.

Atypical Reactivity of Heart Rate Variability to Stress and Depression: Systematic Review of the Literature and Directions for Future Research

PubMed Central

Hamilton, Jessica L.; Alloy, Lauren B.

2017-01-01

Heart rate variability has received growing attention in the depression literature, with several recent meta-analyses indicating that lower resting heart rate variability is associated with depression. However, the role of fluctuations in heart rate variability (or reactivity) in response to stress in depression remains less clear. The present review provides a systematic examination of the literature on heart rate variability reactivity to a laboratory-induced stressor task and depression, including 26 studies of reactivity in heart rate variability and clinical depression, remitted (or history of) depression, and subthreshold depression (or symptom-level depression) among adults, adolescents, and children. In addition to reviewing the findings of these studies, methodological considerations and conceptual gaps in the literature are addressed. We conclude by highlighting the importance of investigating the potential transactional relationship between heart rate variability reactivity and depression and possible mechanisms underlying this relationship. PMID:27697746

Heart rate differentiates urgency and emergency in hypertensive crisis.

PubMed

Al Bannay, Rashed; Böhm, Michael; Husain, Aysha

2013-08-01

To study the clinical significance of presenting blood pressure parameters and heart rate in patients with hypertensive crisis. In patients admitted with hypertensive crisis between January 2011 and May 2011, demography, mode of presentation, co-morbidities, blood pressure readings, and heart rate at presentation were documented. Further clustering of hypertensive crisis into emergency or urgency was based on the presence or absence of target organ involvement. The relationship between blood pressure parameters, heart rate, and other variables was analyzed. 189 patients in sinus rhythm were enrolled in this pilot study. The rate of hypertensive urgency was 56 %, whereas the rate of hypertensive emergency was 44 %, respectively. Subjects with hypertensive emergency had a higher mean heart rate (93 ± 22.7 bpm) than those with urgency (81 ± 11.5 bpm) (P = 0.015). Women had higher heart rates (92 ± 18.5 bpm) than men (86 ± 17.6 bpm) (P = 0.014). Heart rates below 100 bpm had a specificity of 94 %, classifying patients as hypertensive urgency. Tachycardia had a powerful statistical association with hypertensive left ventricular failure (P < 0.0001). Other hemodynamic parameters, including systolic blood pressure, diastolic blood pressure, pulse pressure, and mean blood pressure relates neither to urgency nor to emergency. Diabetic patients with HBA1c levels of more than 53 mmol/mol had a heart rate of more than 100 bpm (P = 0.015) during hypertensive crisis. Normal heart rate is characteristic of hypertensive urgency. Tachycardia in this setting is an ominous sign and denotes hypertensive complications in particular left ventricular failure. Among diabetics, elevated heart rate is associated with poor glycemic control.

Heat transfer in a microvascular network: the effect of heart rate on heating and cooling in reptiles (Pogona barbata and Varanus varius).

PubMed

Seebacher, F

2000-03-21

Thermally-induced changes in heart rate and blood flow in reptiles are believed to be of selective advantage by allowing animal to exert some control over rates of heating and cooling. This notion has become one of the principal paradigms in reptilian thermal physiology. However, the functional significance of changes in heart rate is unclear, because the effect of heart rate and blood flow on total animal heat transfer is not known. I used heat transfer theory to determine the importance of heat transfer by blood flow relative to conduction. I validated theoretical predictions by comparing them with field data from two species of lizard, bearded dragons (Pogona barbata) and lace monitors (Varanus varius). Heart rates measured in free-ranging lizards in the field were significantly higher during heating than during cooling, and heart rates decreased with body mass. Convective heat transfer by blood flow increased with heart rate. Rates of heat transfer by both blood flow and conduction decreased with mass, but the mass scaling exponents were different. Hence, rate of conductive heat transfer decreased more rapidly with increasing mass than did heat transfer by blood flow, so that the relative importance of blood flow in total animal heat transfer increased with mass. The functional significance of changes in heart rate and, hence, rates of heat transfer, in response to heating and cooling in lizards was quantified. For example, by increasing heart rate when entering a heating environment in the morning, and decreasing heart rate when the environment cools in the evening a Pogona can spend up to 44 min longer per day with body temperature within its preferred range. It was concluded that changes in heart rate in response to heating and cooling confer a selective advantage at least on reptiles of mass similar to that of the study animals (0. 21-5.6 kg). Copyright 2000 Academic Press.

The effect of respiratory oscillations in heart rate on detrended fluctuation analysis

NASA Astrophysics Data System (ADS)

Govindan, Rathinaswamy B.; Kota, Srinivas; Al-Shargabi, Tareq; Swisher, Christopher B.; du Plessis, Adre

2017-10-01

Characterization of heart rate using detrended fluctuation analysis (DFA) is impeded by respiratory oscillations. In particular, the short-term exponent measured from 15 to 30 beats is compromised in the DFA. We reconstruct respiratory signal from electrocardiograms and attenuate the respiratory oscillation in the heart rate using a frequency-dependent subtraction approach. We validate this method by applying it to an electrocardiogram signal simulated using a coupled differential equation with the respiratory oscillation modelled using a sine function. The exponent estimated using the proposed approach agreed with the exponent incorporated in the model within a narrow range. In contrast, the exponent obtained from the raw data deviated from the expected value. Furthermore, the exponents obtained for the raw heart rate are smaller than the exponents obtained for the respiration oscillation attenuated heart rate. We apply this approach to heart rate measured from 12 preterm infants that were being treated for prematurity related complications. As observed in the simulated data, we show that compared to the raw heart rate, the respiratory oscillation attenuated heart rate shows higher short-term exponent (p < 0.001).

A prospective study on the impact of heart rate control achieved with metoprolol on cardiac performance, motor function and quality of life in Chinese chronic heart failure patients.

PubMed

Meng, Yong; Liu, Xuelu; Liu, Juan; Cheng, Xianliang

2017-01-15

To prospectively evaluate the impact of metoprolol achieved heart rate (HR) on cardiac-motor function and quality of life (QoL) in chronic heart failure (CHF) patients. Between February 2013 to April 2016, association of HR reduction with haemodynamic indices, motor function and QoL in CHF patients with HR>80bpm receiving metoprolol 23.75mg or 47.5mgq.d was studied. Overall, 154 patients (median age, 66.39years; males, n=101; females, n=53) were enrolled, whose average resting HR decreased significantly from baseline value of 82.72±6.73 to 69.38±3.57, 67.72±2.61, 66.50±3.14 and 64.86±3.21bpm in the 1st, 3rd, 6th and 12th months post metoprolol intervention, respectively (P<0.0001). Similarly, the ejection fraction (r=-0.6461, P<0.0001), cardiac output (r=-0.5238, P<0.0001), cardiac index (r=-0.5378, P<0.0001) and veterans specific activity questionnaire scores (r=-0.4088, P<0.0001) were significantly associated with the reduction in HR after 12months. The improvement in 6-min walk test was independent of HR reduction (P=0.005). Similarly, QoL as measured by short form-8 questionnaire (SF-8) but not Minnesota Living with Heart Failure was significantly improved at the 12th-month. However, this was not associated with the reductions in HR. Metoprolol achieved HR control was associated with improvement in cardiac performance and motor function but not QoL in patients with CHF. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Ongoing right ventricular hemodynamics in heart failure: clinical value of measurements derived from an implantable monitoring system.

PubMed

Adamson, Philip B; Magalski, Anthony; Braunschweig, Frieder; Böhm, Michael; Reynolds, Dwight; Steinhaus, David; Luby, Allyson; Linde, Cecilia; Ryden, Lars; Cremers, Bodo; Takle, Teri; Bennett, Tom

2003-02-19

This study examined the characteristics of continuously measured right ventricular (RV) hemodynamic information derived from an implantable hemodynamic monitor (IHM) in heart failure patients. Hemodynamic monitoring might improve the day-to-day management of patients with chronic heart failure (CHF). Little is known about the characteristics of long-term hemodynamic information in patients with CHF or how such information relates to meaningful clinical events. Thirty-two patients with CHF received a permanent RV IHM system similar to a single-lead pacemaker. Right ventricular systolic and diastolic pressures, heart rate, and pressure derivatives were continuously measured for nine months without using the data for clinical decision-making or management of patients. Data were then made available to clinical providers, and the patients were followed up for 17 months. Pressure characteristics during optimal volume, clinically determined volume-overload exacerbations, and volume depletion events were examined. The effect of IHM on hospitalizations was examined using the patients' historical controls. Long-term RV pressure measurements had either marked variability or minimal time-related changes. During 36 volume-overload events, RV systolic pressures increased by 25 +/- 4% (p < 0.05) and heart rate increased by 11 +/- 2% (p < 0.05). Pressure increases occurred in 9 of 12 events 4 +/- 2 days before the exacerbations requiring hospitalization. Hospitalizations before using IHM data for clinical management averaged 1.08 per patient year and decreased to 0.47 per patient-year (57% reduction, p < 0.01) after hemodynamic data were used. Long-term ambulatory pressure measurements from an IHM may be helpful in guiding day-to-day clinical management, with a potentially favorable impact on CHF hospitalizations.

Heart-Rate and Breath-Rate Monitor

NASA Technical Reports Server (NTRS)

Cooper, T. G.

1983-01-01

Circuit requiring only four integrated circuits (IC's) measures both heart rate and breath rate. Phase-locked loops lock on heart-rate and respiration-rate input signals. Each loop IC contains two phase comparators. Positive-edge-triggered circuit used in making monitors insensitive to dutycycle variations.

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

PubMed Central

Penzel, Thomas; Kantelhardt, Jan W.; Bartsch, Ronny P.; Riedl, Maik; Kraemer, Jan F.; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

2016-01-01

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave). PMID:27826247

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography.

PubMed

Penzel, Thomas; Kantelhardt, Jan W; Bartsch, Ronny P; Riedl, Maik; Kraemer, Jan F; Wessel, Niels; Garcia, Carmen; Glos, Martin; Fietze, Ingo; Schöbel, Christoph

2016-01-01

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However, their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG, and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability (HRV) analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave).

Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs.

PubMed

Suzuki, T; Okamura, K; Kimura, Y; Watanabe, T; Yaegashi, N; Murotsuki, J; Uehara, S; Yajima, A

2000-05-01

The appearance of the sinusoidal heart rate pattern found on fetal cardiotocograms has not been fully explained, either physiologically or clinically. In this study we performed power spectral analysis on the sinusoidal heart rate pattern obtained by administration of arginine vasopressin and atropine sulfate to investigate its frequency components in fetal lambs with long-term instrument implantation. Eleven tests were performed in 4 fetal lambs at 120 to 130 days' gestation. An artificial sinusoidal heart rate pattern was obtained by administration of atropine sulfate and arginine vasopressin in 9 tests. An autoregression model was used to compare the spectral patterns before and during the sinusoidal heart rate pattern. Marked decreases in low-frequency (0.025-0.125 cycles/beat) and high-frequency (0.2-0.5 cycles/beat) areas were observed in the presence of the sinusoidal heart rate pattern. However, there were no significant changes in the very-low-frequency area (0.01-0.025 cycles/beat), which corresponds to the frequency of the sinusoidal heart rate pattern. The sinusoidal heart rate pattern may represent a very low-frequency component inherent in fetal heart rate variability that appears when low- and high-frequency components are reduced as a result of strongly suppressed autonomic nervous activity.

[Analysis of Foetal Heart Rate Data using Complex Software: Comparison of Recurrence Plot of Foetal Heart Rate with the Course of Pregnancy -].

PubMed

Jörn, H; Morgenstern, B; Wassenberg, B; Rath, W

2004-08-01

Is it useful to further analyse foetal heart rate to improve the prediction of pregnancy complications? The analysis of the foetal heart rate is usually based on the variability of the heart rate, i. e. the more variable the heart rate presents - except a decrease - the better the condition of the foetus is. The same concept is applied in our own analysis which differs only in the presentation of the data. We analysed 25 non-stress-tests from unselected third trimester pregnancies using sophisticated software. The recurrence plot (RP) is able to rearrange data from foetal heart rate monitoring in order to make the heart rate variability visible. We developed criteria for a normal and an abnormal test result describing the structure of the diagram to predict an uneventful and a high-risk pregnancy, respectively. 11 out of 11 patients with uneventful course and outcome of pregnancy showed a coarse and blurred RP pattern. 12 out of 14 (86 %) patients developing either intrauterine growth retardation or preeclampsia and requiring caesarean section because of foetal heart rate abnormalities showed a fine and clear RP pattern. Our preliminary results show that it makes sense to further evaluate foetal heart rate variability in order to predict pregnancy complications. Computer programs including the algorithms needed (calculation of the recurrence plot) are not expensive and easy to handle. A widespread use of these programs represents the basis requirement for large controlled clinical trials.

Maternal exercise, season and sex modify the daily fetal heart rate rhythm.

PubMed

Sletten, J; Cornelissen, G; Assmus, J; Kiserud, T; Albrechtsen, S; Kessler, J

2018-05-13

The knowledge on biological rhythms is rapidly expanding. We aimed to define the longitudinal development of the daily (24-hour) fetal heart rate rhythm in an unrestricted, out-of-hospital setting and to examine the effects of maternal physical activity, season and fetal sex. We recruited 48 women with low-risk singleton pregnancies. Using a portable monitor for continuous fetal electrocardiography, fetal heart rate recordings were obtained around gestational weeks 24, 28, 32 and 36. Daily rhythms in fetal heart rate and fetal heart rate variation were detected by cosinor analysis; developmental trends were calculated by population-mean cosinor and multilevel analysis. For the fetal heart rate and fetal heart rate variation, a significant daily rhythm was present in 122/123 (99.2%) and 116/121 (95.9%) of the individual recordings respectively. The rhythms were best described by combining cosine waves with periods of 24 and 8 hours. With increasing gestational age, the magnitude of the fetal heart rate rhythm increased, and the peak of the fetal heart rate variation rhythm shifted from a mean of 14:25 (24 weeks) to 20:52 (36 weeks). With advancing gestation, the rhythm-adjusted mean value of the fetal heart rate decreased linearly in females (P < .001) and nonlinearly in males (quadratic function, P = .001). At 32 and 36 weeks, interindividual rhythm diversity was found in male fetuses during higher maternal physical activity and during the summer season. The dynamic development of the daily fetal heart rate rhythm during the second half of pregnancy is modified by fetal sex, maternal physical activity and season. © 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

[Trend analysis on the death rate of ischemic heart disease and cerebrovascular disease among Xuzhou residents from 2011 to 2015].

PubMed

Chen, P P; Lou, P A; Zhang, P; Qiao, C; Li, T; Dong, Z M

2017-07-24

Objective: To analyze the epidemiological characteristics and trend of ischemic heart disease and cerebrovascular disease mortality among Xuzhou residents from 2011 to 2015. Methods: The mortality data of the ischemic heart disease and cerebrovascular disease were obtained from the registration disease surveillance system covering the residents of the city from 2011 to 2015. Ischemic heart disease and cerebrovascular disease were identified according to the international classification of diseases (ICD-10), Ischemic heart diseases include I20 to I25 (angina pectoris, acute myocardial infarction, certain current complications following acute myocardial infarction, other acute ischemic heart diseases chronic ischemic heart disease); cerebrovascular diseases include I60 to I69 (subarachnoid hemorrhage, intracerebral hemorrhage, other non-traumatic hemorrhage, cerebral infarction, stroke not specified as hemorrhage or infarction, other cerebrovascular diseases, sequelae of cerebrovascular disease). Results: (1)From 2011 to 2015, the chronic ischemia Cardio-Cerebrovascular disease mortality of residents in Xuzhou was 261.2 per one hundred thousand (129 950/49 748 321), 269.9 per one hundred thousand(69 562/25 775 930)for male residents, 252.0 per one hundred thousand(60 388/23 972 391)for female residents, the mortality rate in men was significantly higher than that in women ( P <0.05). The chronic ischemic Cardio-Cerebrovascular disease mortality rate of urban residents was 243.8 per one hundred thousand(17 049/6 993 787), which was lower than the rate of rural residents (264.0 per one hundred thousand(112 901/42 754 534), P <0.05). (2)From 2011 to 2015, the mortality rate of ischemic heart disease in Xuzhou city remained unchanged: 117.1 per one hundred thousand(11 416/9 747 768), 126.8 per one hundred thousand(12 177/9 600 745), 112.0 per one hundred thousand(11 184/9 986 877), 115.2 per one hundred thousand(11 697/10 151 842), 117.1 per one hundred thousand(12 019/10 261 089, P >0.05). The mortality rate of cerebrovascular disease were 154.0 per one hundred thousand(15 014/9 747 768), 155.9 per one hundred thousand(14 964/9 600 745), 143.5 per one hundred thousand(14 330/9 986 877), 135.5 per one hundred thousand(13 752/10 151 842), 130.6 per one hundred thousand(13 397/10 261 089)respectively, presented with a downward trend( P <0.05). The mortality rate of ischemic cerebrovascular disease were 62.7 per one hundred thousand(6 108/9 747 768), 74.7 per one hundred thousand(7 176/9 600 745), 72.3 per one hundred thousand(7 221/9 986 877), 70.9 per one hundred thousand(7 200/10 151 842)and 72.4 per one hundred thousand(7 431/10 261 089)respectively( P >0.05). The mortality rate of hemorrhagic cerebrovascular disease were 77.6 per one hundred thousand(7 562/9 747 768), 71.6 per one hundred thousand(6 873/9 600 745), 61.2 per one hundred thousand(6 115/9 986 877), 55.3 per one hundred thousand(5 613/10 151 842)and 46.4 per one hundred thousand(4 763/10 261 089)respectively, presented with a downward trend( P <0.05). (3)The average death age due to ischemic heart diseases of all residents was (77.0±13.1)years old, (76.4±13.2) years old among urban residents, (77.1±7.1 )years old among rural residents, (74.3±13.5)years old for male residents, (80.0±12.0) years old for female residents. The average death age due to ischemic cerebrovascular diseases of all residents was (76.4±11.9)years old, (76.5±12.3) years old among urban residents, (76.4±11.9 )years old among rural residents, (74.3±12.2)years old among male residents, (79.0±11.1) years old among female residents. From 2011 to 2015, the death age due to ischemic heart diseases were (76.3±13.5), (77.2±13.0), (76.6±13.3), (77.1±12.9)and(77.8±12.9)years old respectively; the death age due to cerebrovascular disease were (75.8±12.1), (76.3±11.8), (76.6±11.8), (76.6±12.0)and(77.1±11.9)years old respectively. The Spearman rank correlation analysis showed that the death age due to ischemic heart disease and cerebrovascular disease increased year by year in the past 5 years. ( r value was 0.033 and 0.038, respectively, all P <0.01). Conclusion: From 2011 to 2015, the mortality of hemorrhagic cerebrovascular disease decreased, while the mortality of ischemic cardiovascular and cerebrovascular diseases remained unchanged among Xuzhou residents.

Diagnostic accuracy of heart-rate recovery after exercise in the assessment of diabetic cardiac autonomic neuropathy.

PubMed

Sacre, J W; Jellis, C L; Coombes, J S; Marwick, T H

2012-09-01

Poor prognosis associated with blunted post-exercise heart-rate recovery may reflect autonomic dysfunction. This study sought the accuracy of post-exercise heart-rate recovery in the diagnosis of cardiac autonomic neuropathy, which represents a serious, but often unrecognized complication of Type 2 diabetes. Clinical assessment of cardiac autonomic neuropathy and maximal treadmill exercise testing for heart-rate recovery were performed in 135 patients with Type 2 diabetes and negative exercise echocardiograms. Cardiac autonomic neuropathy was defined by abnormalities in ≥ 2 of 7 autonomic function markers, including four cardiac reflex tests and three indices of short-term (5-min) heart-rate variability. Heart-rate recovery was defined at 1-, 2- and 3-min post-exercise. Patients with cardiac autonomic neuropathy (n = 27; 20%) had lower heart-rate recovery at 1-, 2- and 3-min post-exercise (P < 0.01). Heart-rate recovery demonstrated univariate associations with autonomic function markers (r-values 0.20-0.46, P < 0.05). Area under the receiver-operating characteristic curve revealed good diagnostic performance of all heart-rate recovery parameters (range 0.80-0.83, P < 0.001). Optimal cut-offs for heart-rate recovery at 1-, 2- and 3-min post-exercise were ≤ 28 beats/min (sensitivity 93%, specificity 69%), ≤ 50 beats/min (sensitivity 96%, specificity 63%) and ≤ 52 beats/min (sensitivity 70%, specificity 84%), respectively. These criteria predicted cardiac autonomic neuropathy independently of relevant clinical and exercise test information (adjusted odds ratios 7-28, P < 0.05). Post-exercise heart-rate recovery provides an accurate diagnostic test for cardiac autonomic neuropathy in Type 2 diabetes. The high sensitivity and modest specificity suggests heart-rate recovery may be useful to screen for patients requiring clinical autonomic evaluation. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

Physiological characteristics of badminton match play.

PubMed

Faude, Oliver; Meyer, Tim; Rosenberger, Friederike; Fries, Markus; Huber, Günther; Kindermann, Wilfried

2007-07-01

The present study aimed at examining the physiological characteristics and metabolic demands of badminton single match play. Twelve internationally ranked badminton players (eight women and four men) performed an incremental treadmill test [VO(2peak = )50.3 +/- 4.1 ml min(-1) kg(-1) (women) and 61.8 +/- 5.9 ml min(-1) kg(-1) (men), respectively]. On a separate day, they played a simulated badminton match of two 15 min with simultaneous gas exchange (breath-by-breath) and heart rate measurements. Additionally, blood lactate concentrations were determined before, after 15 min and at the end of the match. Furthermore, the duration of rallies and rests in between, the score as well as the number of shots per rally were recorded. A total of 630 rallies was analysed. Mean rally and rest duration were 5.5 +/- 4.4 s and 11.4 +/- 6.0 s, respectively, with an average 5.1 +/- 3.9 shots played per rally. Mean oxygen uptake (VO(2)), heart rate (HR), and blood lactate concentrations during badminton matches were 39.6 +/- 5.7 ml min(-1) kg(-1) (73.3% VO(2peak)), 169 +/- 9 min(-1) (89.0% HR(peak)) and 1.9 +/- 0.7 mmol l(-1), respectively. For a single subject 95% confidence intervals for VO(2) and HR during match play were on average 45.7-100.9% VO(2peak) and 78.3-99.8% HR(peak). High average intensity of badminton match play and considerable variability of several physiological variables demonstrate the importance of anaerobic alactacid and aerobic energy production in competitive badminton. A well-developed aerobic endurance capacity seems necessary for fast recovery between rallies or intensive training workouts.

Reduction in Heart Rate Variability with Traffic and Air Pollution in Patients with Coronary Artery Disease

PubMed Central

Zanobetti, Antonella; Gold, Diane R.; Stone, Peter H.; Suh, Helen H.; Schwartz, Joel; Coull, Brent A.; Speizer, Frank E.

2010-01-01

Introduction Ambient particulate pollution and traffic have been linked to myocardial infarction and cardiac death risk. Possible mechanisms include autonomic cardiac dysfunction. Methods In a repeated-measures study of 46 patients 43–75 years of age, we investigated associations of central-site ambient particulate pollution, including black carbon (BC) (a marker for regional and local traffic), and report of traffic exposure with changes in half-hourly averaged heart rate variability (HRV), a marker of autonomic function measured by 24-hr Holter electrocardiogram monitoring. Each patient was observed up to four times within 1 year after a percutaneous intervention for myocardial infarction, acute coronary syndrome without infarction, or stable coronary artery disease (4,955 half-hour observations). For each half-hour period, diary data defined whether the patient was home or not home, or in traffic. Results A decrease in high frequency (HF; an HRV marker of vagal tone) of −16.4% [95% confidence interval (CI), −20.7 to −11.8%] was associated with an interquartile range of 0.3-μg/m3 increase in prior 5-day averaged ambient BC. Decreases in HF were independently associated both with the previous 2-hr averaged BC (−10.4%; 95% CI, −15.4 to −5.2%) and with being in traffic in the previous 2 hr (−38.5%; 95% CI, −57.4 to −11.1%). We also observed independent responses for particulate air matter with aerodynamic diameter ≤ 2.5 μm and for gases (ozone or nitrogen dioxide). Conclusion After hospitalization for coronary artery disease, both particulate pollution and being in traffic, a marker of stress and pollution, were associated with decreased HRV. PMID:20064780

Contemporary Primary Prevention Aspirin Use by Cardiovascular Disease Risk: Impact of US Preventive Services Task Force Recommendations, 2007-2015: A Serial, Cross-sectional Study.

PubMed

Van't Hof, Jeremy R; Duval, Sue; Walts, Adrienne; Kopecky, Stephen L; Luepker, Russell V; Hirsch, Alan T

2017-10-03

No previous study has evaluated the impact of past US Preventive Services Task Force statements on primary prevention (PP) aspirin use in a primary care setting. The aim of this study was to evaluate temporal changes in PP aspirin use in a primary care population, stratifying patients by their 10-year global cardiovascular disease risk, in response to the 2009 statement. This study estimated biannual aspirin use prevalence using electronic health record data from primary care clinics within the Fairview Health System (Minnesota) from 2007 to 2015. A total of 94 270 patient encounters had complete data to estimate a 10-year cardiovascular disease risk score using the 2013 American College of Cardiology/American Heart Association global risk estimator. Patients were stratified into low- (<10%), intermediate- (10-20%), and high- (≥20%) risk groups. Over the 9-year period, PP aspirin use averaged 43%. When stratified by low, intermediate and high risk, average PP aspirin use was 41%, 63%, and 73%, respectively. Average PP aspirin use decreased after the publication of the 2009 US Preventive Services Task Force recommendation statement: from 45% to 40% in the low-risk group; from 66% to 62% in the intermediate-risk group; and from 76% to 73% in the high-risk group, before and after the guideline. Publication of the 2009 US Preventive Services Task Force recommendation was not associated with an increase in aspirin use. High risk PP patients utilized aspirin at high rates. Patients at intermediate risk were less intensively treated, and patients at low risk used aspirin at relatively high rates. These data may inform future aspirin guideline dissemination. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

The effect of heat transfer mode on heart rate responses and hysteresis during heating and cooling in the estuarine crocodile Crocodylus porosus.

PubMed

Franklin, Craig E; Seebacher, Frank

2003-04-01

The effect of heating and cooling on heart rate in the estuarine crocodile Crocodylus porosus was studied in response to different heat transfer mechanisms and heat loads. Three heating treatments were investigated. C. porosus were: (1) exposed to a radiant heat source under dry conditions; (2) heated via radiant energy while half-submerged in flowing water at 23 degrees C and (3) heated via convective transfer by increasing water temperature from 23 degrees C to 35 degrees C. Cooling was achieved in all treatments by removing the heat source and with C. porosus half-submerged in flowing water at 23 degrees C. In all treatments, the heart rate of C. porosus increased markedly in response to heating and decreased rapidly with the removal of the heat source. Heart rate during heating was significantly faster than during cooling at any given body temperature, i.e. there was a significant heart rate hysteresis. There were two identifiable responses to heating and cooling. During the initial stages of applying or removing the heat source, there was a dramatic increase or decrease in heart rate ('rapid response'), respectively, indicating a possible cardiac reflex. This rapid change in heart rate with only a small change or no change in body temperature (<0.5 degrees C) resulted in Q(10) values greater than 4000, calling into question the usefulness of this measure on heart rate during the initial stages of heating and cooling. In the later phases of heating and cooling, heart rate changed with body temperature, with Q(10) values of 2-3. The magnitude of the heart rate response differed between treatments, with radiant heating during submergence eliciting the smallest response. The heart rate of C. porosus outside of the 'rapid response' periods was found to be a function of the heat load experienced at the animal surface, as well as on the mode of heat transfer. Heart rate increased or decreased rapidly when C. porosus experienced large positive (above 25 W) or negative (below -15 W) heat loads, respectively, in all treatments. For heat loads between -15 W and 20 W, the increase in heart rate was smaller for the 'unnatural' heating by convection in water compared with either treatment using radiant heating. Our data indicate that changes in heart rate constitute a thermoregulatory mechanism that is modulated in response to the thermal environment occupied by the animal, but that heart rate during heating and cooling is, in part, controlled independently of body temperature.

Modest weight loss in moderately overweight postmenopausal women improves heart rate variability.

PubMed

Mouridsen, Mette Rauhe; Bendsen, Nathalie Tommerup; Astrup, Arne; Haugaard, Steen Bendix; Binici, Zeynep; Sajadieh, Ahmad

2013-08-01

To evaluate the effects of weight loss on heart rate (HR) and heart rate variability (HRV) parameters in overweight postmenopausal women. Forty-nine overweight postmenopausal women with an average body mass index of 28.8 ± 1.9 kg/m(2) underwent a 12-week dietary weight-loss programme. Accepted variables for characterization of HRV were analysed before and after the weight loss by 24-h ambulatory ECG monitoring; mean and standard deviation for the time between normal-to-normal complexes (MeanNN and SDNN, respectively), and the mean of standard deviations of normal-to-normal intervals for each 5-min period (SDNNindex). Baseline body fat mass (FM%) and changes in body composition was determined by dual X-ray absorptiometry. Before and after the weight-loss period, total abdominal fat, intra-abdominal fat (IAAT), and subcutaneous abdominal fat (SCAT) were measured by single-slice MRI at L3. The weight loss of 3.9 ± 2.0 kg was accompanied by an improvement of HRV. SDNN increased by 9.2% (p = 0.003) and SDNNindex increased by 11.4% (p = 0.0003). MeanNN increased by 2.4%, reflecting a decrease in mean heart rate from 74.1 to 72.3 beats/min (p = 0.033). Systolic blood pressure (SBP) decreased by 2.7%, total cholesterol by 5.1% and high-sensitivity C-reactive protein (hsCRP) by 15.8% (p = 0.002). Improvements in SDNN and cholesterol were correlated with weight loss (r = -0.329, p = 0.024 and r = 0.327, p = 0.020, respectively) but changes in HR, SBP, and hsCRP were not. IAAT and the IAAT/SCAT-ratio were found to be negatively associated with HRV parameters but changes in body composition were not associated with changes in HRV. The observed improvement of HRV seems to be facilitated by weight loss. IAAT and the IAAT/SCAT ratio were found to be associated with low HRV.

Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.

PubMed

St Helen, Gideon; Havel, Christopher; Dempsey, Delia A; Jacob, Peyton; Benowitz, Neal L

2016-03-01

To measure the systemic retention of nicotine, propylene glycol (PG) and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. E-cigarette users recruited over the internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use. San Francisco, California, USA. Thirteen healthy, experienced adult e-cigarette users (six females and seven males). Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. E-cigarettes delivered an average of 1.33 (0.87-1.79) mg [mean and 95% confidence interval (CI)] of nicotine, and 93.8% of the inhaled dose, 1.22 (0.80-1.66) was systemically retained. Average maximum plasma nicotine concentration (Cmax ) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax ) was 2-5 minutes. One participant had Tmax of 30 minutes. 84.4% and 91.7% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 beats per minute after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarette users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. © 2015 Society for the Study of Addiction.

Detection of a Heart Defect in the Fetus

MedlinePlus

... problems : There is a wide range of acceptable fetal heart rates (normal is between 120 and 160 but many ... usually go away shortly after birth. More important fetal heart problems include tachycardia (hear rate too fast) and bradycardia (heart rate too slow). ...

Mindfulness Dampens Cardiac Responses to Motion Scenes of Violence.

PubMed

Brzozowski, Artur; Gillespie, Steven M; Dixon, Louise; Mitchell, Ian J

2018-01-01

Mindfulness is linked with improved regulatory processes of attention and emotion. The potential benefits of mindfulness are vast, including more positive emotional states and diminished arousal in response to emotional stimuli. This study aims to expand of the current knowledge of the mechanisms of mindfulness by relating the latter to cardiovascular processes. The paper describes two studies which investigated the relationship of trait mindfulness to self-report measures of emotions elicited during a violent video clip and cardiovascular responses to the clip. Both studies recruited male and female participants, mainly university undergraduate students. The clip was 5-min-long and evoked mainly feelings of tension and disgust. In study 1, we found that higher scores for trait mindfulness were associated with increased scores for valence ( r  = .370, p  = .009), indicating a more positive interpretation of the clip. In study 2, the average heart rate during the clip was lower than during the preceding ( p  < .05) and following ( p  < .01) non-exposure conditions. Higher trait mindfulness was related to diminished heart rate reactivity ( r  = -.364, p  = .044) and recovery ( r  = -.415, p  = .020). This latter effect was obtained only when trait anxiety was used as a statistical covariate. Additionally, increased trait mindfulness was accompanied by higher resting heart rate ( r  = .390, p  = .027). These outcomes suggest that mindfulness is linked with reductions in negative feelings evoked by violent motion stimuli.

Lifestyle intervention improves heart rate recovery from exercise in adults with type 2 diabetes: results from the Look AHEAD study.

PubMed

Ribisl, Paul M; Gaussoin, Sarah A; Lang, Wei; Bahnson, Judy; Connelly, Stephanie A; Horton, Edward S; Jakicic, John M; Killean, Tina; Kitzman, Dalane W; Knowler, William C; Stewart, Kerry J

2012-01-01

The primary aims of this paper were (1) to evaluate the influence of intensive lifestyle weight loss and exercise intervention (ILI) compared with diabetes support and education (DSE) upon Heart Rate Recovery (HRR) from graded exercise testing (GXT) and (2) to determine the independent and combined effects of weight loss and fitness changes upon HRR. In 4503 participants (45-76 years) who completed 1 year of intervention, HRR was measured after a submaximal GXT to compare the influence of (ILI) with (DSE) upon HRR. Participants assigned to ILI lost an average 8.6% of their initial weight versus 0.7% in DSE group (P < 0.001) while mean fitness increased in ILI by 20.9% versus 5.8% in DSE (P < 0.001). At Year 1, all exercise and HRR variables in ILI improved (P < 0.0001) versus DSE: heart rate (HR) at rest was lower (72.8 ± 11.4 versus 77.7 ± 11.7 b/min), HR range was greater (57.7 ± 12.1 versus 53.1 ± 12.4 b/min), HR at 2 minutes was lower (89.3 ± 21.8 versus 93.0 ± 12.1 b/min), and HRR was greater (41.25 ± 22.0 versus 37.8 ± 12.5 b/min). Weight loss and fitness gain produced significant separate and independent improvements in HRR.

Heart Rate Monitors

NASA Technical Reports Server (NTRS)

1990-01-01

Under a NASA grant, Dr. Robert M. Davis and Dr. William M. Portnoy came up with a new type of electrocardiographic electrode that would enable long term use on astronauts. Their invention was an insulated capacitive electrode constructed of a thin dielectric film. NASA subsequently licensed the electrode technology to Richard Charnitski, inventor of the VersaClimber, who founded Heart Rate, Inc., to further develop and manufacture personal heart monitors and to produce exercise machines using the technology for the physical fitness, medical and home markets. Same technology is on both the Home and Institutional Model VersaClimbers. On the Home Model an infrared heart beat transmitter is worn under exercise clothing. Transmitted heart rate is used to control the work intensity on the VersaClimber using the heart rate as the speedometer of the exercise. This offers advantages to a full range of users from the cardiac rehab patient to the high level physical conditioning of elite athletes. The company manufactures and markets five models of the 1*2*3 HEART RATE monitors that are used wherever people exercise to accurately monitor their heart rate. Company is developing a talking heart rate monitor that works with portable headset radios. A version of the heart beat transmitter will be available to the manufacturers of other aerobic exercise machines.

Exercise Heart Rate as a Predictor of Oxygen Consumption During Decompression from Saturation Diving

DTIC Science & Technology

2002-11-01

Swimming," nt. J. Sports Med., Vol. 18, (1997), pp. 347-353 3. L. B. Rowell, Human Circulation: Regulation during Physical Stress (New York: Oxford...University Press, 1986). 4. American College of Sports Medicine; B. A. Franklin, W. H. Whaley, and E. T. Howley, eds., ACSM’s Guidelines for Exercise...function of oxygen consumption (VO 2)(L/min). Averages of regression parameters for individual subjects. IMMERSED HRvs . V0 2 Depth Slope Min Max Incpt, Min

Long-term survival of heart transplant recipients with lung cancer: the role of chest computed tomography screening.

PubMed

Mohammadi, S; Bonnet, N; Leprince, P; Charbonneau, E; Berberian, G; Aslani, M; Silvaggio, G; Dorent, R; Pavie, A; Gandjbakhch, I

2007-10-01

We sought to evaluate the screening modality and outcome of lung cancer occurring in heart transplant recipients (HTR) during a 21-year period. We conducted a retrospective review to investigate the incidence, risk factors, screening modality, treatment, and outcomes in HTR with lung cancer. We compared them with a case-matched HTR control group. Out of 829 recipients of heart transplants, 19 cases of bronchogenic carcinoma were found either by routine chest X-ray (n = 10), chest computed tomographic (CT) scanning (n = 4), or by assessment of clinical symptoms (n = 5). The mean time from transplantation to bronchogenic carcinoma diagnosis was 68.8 +/- 42.4 months. A history of smoking was the only risk factor in HTR with bronchogenic carcinoma compared to their case-matched HTR control group ( P < 0.05). Of 18 patients with non-small cell lung cancer (NSCLC), 13 underwent surgery and 5 with advanced cancer underwent chemotherapy and/or radiotherapy. NSCLC was diagnosed by chest X-ray (n = 10), and 6 of these patients died after an average of 43.7 +/- 62.2 months following cancer detection. NSCLC was also diagnosed on the basis of clinical symptoms (n = 4), and 2 of these patients died after a mean follow-up of 9 +/- 4.2 months after cancer diagnosis. All 4 patients in whom cancer was detected by CT scan were alive at an average of 53.5 +/- 36.7 months following cancer detection. The survival rates did not differ between the study and control groups ( P = 0.5). Optimal outcomes of treatment for primary lung cancer after heart transplantation seem to be related to early detection. A high proportion of deaths from NSCLC may be prevented by chest CT scan screening.

Health risk behaviors in adolescents and emerging adults with congenital heart disease: psychometric properties of the Health Behavior Scale-Congenital Heart Disease.

PubMed

Goossens, Eva; Luyckx, Koen; Mommen, Nele; Gewillig, Marc; Budts, Werner; Zupancic, Nele; Moons, Philip

2013-12-01

To optimize long-term outcomes, patients with congenital heart disease (CHD) should adopt health-promoting behaviors. Studies on health behavior in afflicted patients are scarce and comparability of study results is limited. To enlarge the body of evidence, we have developed the Health Behavior Scale-Congenital Heart Disease (HBS-CHD). We examined the psychometric properties of the HBS-CHD by providing evidence for (a) the content validity; (b) validity based on the relationships with other variables; (c) reliability in terms of stability; and (d) responsiveness. Ten experts rated the relevance of the HBS-CHD items. The item content validity index (I-CVI) and the averaged scale content validity index (S-CVI/Ave); the modified multi-rater Kappa and proportion of missing values for each question were calculated. Relationships with other variables were evaluated using six hypotheses that were tested in 429 adolescents with CHD. Stability of the instrument was assessed using Heise's method; and responsiveness was tested by calculating the Guyatt's Responsiveness Index (GRI). Overall, 86.3% of the items had a good to excellent content validity; the S-CVI/Ave (0.81) and multi-rater Kappa (0.78) were adequate. The average proportion of missing values was low (1.2%). Because five out of six hypotheses were confirmed, evidence for the validity of the HBS-CHD based on relationships with other variables was provided. The stability of the instrument could not be confirmed based on our data. The GRI showed good to excellent capacity of the HBS-CHD to detect clinical changes in the health behavior over time. We found that the HBS-CHD is a valid and responsive questionnaire to assess health behaviors in patients with CHD.

Cardiovascular Disease and Patterns of Change in Functional Status Over 15 Years: Findings From the Atherosclerosis Risk in Communities (ARIC) Study.

PubMed

Kucharska-Newton, Anna; Griswold, Michael; Yao, Zhihao Howard; Foraker, Randi; Rose, Kathryn; Rosamond, Wayne; Wagenknecht, Lynne; Koton, Silvia; Pompeii, Lisa; Windham, B Gwen

2017-03-01

Cardiovascular disease (CVD) is the leading cause of premature disability, yet few prospective studies have examined functional status (FS) among persons with CVD. Our aim was to examine patterns of change in FS prior to and after hospitalization for nonfatal myocardial infarction, stroke, and heart failure among members of the Atherosclerosis Risk in Communities (ARIC) study cohort. FS was assessed using a modified Rosow-Breslau questionnaire administered during routine annual telephone interviews conducted from 1993 through 2007 among 15 277 ARIC study participants. An FS score was constructed as a summary measure of responses to questions about participants' ability to perform selected tasks of daily living (eg, walking half a mile, climbing stairs). Incidence of CVD was assessed through ARIC surveillance of hospitalized events. Rate of change in FS over time prior to and following a CVD event was examined using generalized estimating equations. A decline in FS was observed on average 2 years prior to a myocardial infarction hospitalization and on average 3 years prior to a stroke or heart failure hospitalization. FS post-myocardial infarction declined relative to pre-event levels but improved to close to pre-myocardial infarction levels within 3 years. Decline in FS following incident heart failure and stroke remained over time. Observed patterns of change in FS did not differ appreciably by race or sex. This study documents that a decline in FS precedes incidence of CVD-related hospitalization by at least 2 years, providing a strong argument for routine preventative assessment of FS among older adults. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Effects of far infrared rays irradiated from ceramic material (BIOCERAMIC) on psychological stress-conditioned elevated heart rate, blood pressure, and oxidative stress-suppressed cardiac contractility.

PubMed

Leung, Ting-Kai; Chen, Chien-Ho; Tsai, Shih-Ying; Hsiao, George; Lee, Chi-Ming

2012-10-31

The present study examined the effects of BIOCERAMIC on psychological stress-conditioned elevated heart rate, blood pressure and oxidative stress-suppressed cardiac contractility using in vivo and in vitro animal models. We investigated the effects of BIOCERAMIC on the in vivo cardiovascular hemodynamic parameters of rats by monitoring their heart rates, systolic blood pressure, mean blood pressure and diastolic blood pressure. Thereafter, we assayed its effects on the heart rate in an isolated frog heart with and without adrenaline stimulation, and on cardiac contractility under oxidative stress. BIOCERAMIC caused significant decreases in heart rates and systolic and mean blood pressure in the stress-conditioned heart rate rat models (P < 0.05), as well as in the experimental models of an isolated frog heart with and without adrenaline stimulation (P < 0.05), and normalized cardiac contractility under oxidative stress (P < 0.05). BIOCERAMIC may, therefore, normalize the effects of psychological stress and oxidative stress conditions.

Heart rate variability alterations in late life depression: A meta-analysis.

PubMed

Brown, Lydia; Karmakar, Chandan; Gray, Richard; Jindal, Ripu; Lim, Terrence; Bryant, Christina

2018-08-01

There is strong evidence for a bi-directional relationship between heart-health and depression in later life, but the physiological mechanisms underlying this relationship remain unclear. Heart rate variability is one promising factor that might help explain this relationship. We present results of a meta-analysis that considers heart rate variability alterations in older adults with depression. Literature search of Embase, PsychInfo and Medline revealed five clinical studies and six observational studies that examined the relationship between heart rate variability and depression in adults with a mean age over 60. These studies were included in this meta-analysis. Heart rate variability was reduced among older adults with clinical depression (N = 550), relative to healthy controls (Hedges' g = -0.334, 95%CI [-0.579, -0.090], p = .007). When high-frequency and low-frequency heart rate variability were investigated separately, only low-frequency heart rate variability was significantly reduced in depressed patients (Hedges' g = -0.626, 95%CI [-1.083, -0.169], p = .007). A similar but weaker pattern of results was found in the observational studies. Most findings remained significant among unmedicated depressed older adults. Evidence of effect-size heterogeneity was found in the clinical studies, indicating the need for more well-designed research in the area. Heart rate variability is reduced among older adults with depression, and this effect is not fully attributable to antidepressant medication use. Specifically, low-frequency heart rate variability may be reduced in depressed older adults. Heart rate variability warrants further attention, as it could help inform research into the prevention and treatment of depression in later life. Copyright © 2018 Elsevier B.V. All rights reserved.

Beating-heart registration for organ-mounted robots.

PubMed

Wood, Nathan A; Schwartzman, David; Passineau, Michael J; Moraca, Robert J; Zenati, Marco A; Riviere, Cameron N

2018-03-06

Organ-mounted robots address the problem of beating-heart surgery by adhering to the heart, passively providing a platform that approaches zero relative motion. Because of the quasi-periodic deformation of the heart due to heartbeat and respiration, registration must address not only spatial registration but also temporal registration. Motion data were collected in the porcine model in vivo (N = 6). Fourier series models of heart motion were developed. By comparing registrations generated using an iterative closest-point approach at different phases of respiration, the phase corresponding to minimum registration distance is identified. The spatiotemporal registration technique presented here reduces registration error by an average of 4.2 mm over the 6 trials, in comparison with a more simplistic static registration that merely averages out the physiological motion. An empirical metric for spatiotemporal registration of organ-mounted robots is defined and demonstrated using data from animal models in vivo. Copyright © 2018 John Wiley & Sons, Ltd.

Fractal Based Analysis of the Influence of Odorants on Heart Activity

NASA Astrophysics Data System (ADS)

Namazi, Hamidreza; Kulish, Vladimir V.

2016-12-01

An important challenge in heart research is to make the relation between the features of external stimuli and heart activity. Olfactory stimulation is an important type of stimulation that affects the heart activity, which is mapped on Electrocardiogram (ECG) signal. Yet, no one has discovered any relation between the structures of olfactory stimuli and the ECG signal. This study investigates the relation between the structures of heart rate and the olfactory stimulus (odorant). We show that the complexity of the heart rate is coupled with the molecular complexity of the odorant, where more structurally complex odorant causes less fractal heart rate. Also, odorant having higher entropy causes the heart rate having lower approximate entropy. The method discussed here can be applied and investigated in case of patients with heart diseases as the rehabilitation purpose.

FPGA Implementation of Heart Rate Monitoring System.

PubMed

Panigrahy, D; Rakshit, M; Sahu, P K

2016-03-01

This paper describes a field programmable gate array (FPGA) implementation of a system that calculates the heart rate from Electrocardiogram (ECG) signal. After heart rate calculation, tachycardia, bradycardia or normal heart rate can easily be detected. ECG is a diagnosis tool routinely used to access the electrical activities and muscular function of the heart. Heart rate is calculated by detecting the R peaks from the ECG signal. To provide a portable and the continuous heart rate monitoring system for patients using ECG, needs a dedicated hardware. FPGA provides easy testability, allows faster implementation and verification option for implementing a new design. We have proposed a five-stage based methodology by using basic VHDL blocks like addition, multiplication and data conversion (real to the fixed point and vice-versa). Our proposed heart rate calculation (R-peak detection) method has been validated, using 48 first channel ECG records of the MIT-BIH arrhythmia database. It shows an accuracy of 99.84%, the sensitivity of 99.94% and the positive predictive value of 99.89%. Our proposed method outperforms other well-known methods in case of pathological ECG signals and successfully implemented in FPGA.

Changes in heart rate variability are associated with expression of short-term and long-term contextual and cued fear memories.

PubMed

Liu, Jun; Wei, Wei; Kuang, Hui; Zhao, Fang; Tsien, Joe Z

2013-01-01

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I) and a more variable phase (stage-II). We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice.

Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

PubMed

Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

2015-01-01

Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Identification of heart rate–associated loci and their effects on cardiac conduction and rhythm disorders

PubMed Central

den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; Van Der Harst, Pim; Hayward, Caroline; Heijer, Martin Den; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian’an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O’Reilly, Paul F; Padmanabhan, Sandosh; Pourcain, Beate St.; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Åsa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Leach, Irene Mateo; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O’Connell, Jeffrey R; O’Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; Van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F

2013-01-01

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate–increasing and heart rate–decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets. PMID:23583979

An open-source LabVIEW application toolkit for phasic heart rate analysis in psychophysiological research.

PubMed

Duley, Aaron R; Janelle, Christopher M; Coombes, Stephen A

2004-11-01

The cardiovascular system has been extensively measured in a variety of research and clinical domains. Despite technological and methodological advances in cardiovascular science, the analysis and evaluation of phasic changes in heart rate persists as a way to assess numerous psychological concomitants. Some researchers, however, have pointed to constraints on data analysis when evaluating cardiac activity indexed by heart rate or heart period. Thus, an off-line application toolkit for heart rate analysis is presented. The program, written with National Instruments' LabVIEW, incorporates a variety of tools for off-line extraction and analysis of heart rate data. Current methods and issues concerning heart rate analysis are highlighted, and how the toolkit provides a flexible environment to ameliorate common problems that typically lead to trial rejection is discussed. Source code for this program may be downloaded from the Psychonomic Society Web archive at www.psychonomic.org/archive/.

Effect of antiarrhythmic therapy with intravenous loading dose of amiodarone: evidence for an altered response in diabetic patients.

PubMed

Iervasi, G; Clerico, A; Bonini, R; Nannipieri, M; Manfredi, C; Sabatino, L; Biagini, A; Donato, L

1998-01-01

Amiodarone, a potent class III antiarrhythmic agent with adrenergic antagonism properties, is administered increasingly to diabetic patients with cardiac arrhythmias refractory to all other available forms of therapy. Because a large percentage of diabetic patients show a perturbed autonomic regulation of the cardiovascular system, including a pertubed regulation of heart rate, we studied the antiarrhythmic response as well as the early effects (within 5 days) on heart rate of an intravenous amiodarone loading dose in diabetic patients. Seven type II (noninsulin-dependent) diabetic patients (age 64.7 +/- 9.7 years), affected by uncontrolled atrial fibrilation or atrial flutter, were enrolled for the study and a group of 12 well-matched (for age, sex and arrhythmia) nondiabetic patients served as a control group. It was found that before amiodarone administration, nondiabetic patients showed significantly wider variations in the circadian rhythm of heart rate values than diabetic patients (p = 0.0062, unpaired t-test). In all patients but one (who was nondiabetic), amiodarone treatment resulted in a cardioversion to sinus rhythm. After amiodarone administration, nondiabetic patients showed a significantly greater decrease (p = 0.0011) in heart rate values in comparison with the diabetic group (-35% vs. -20% on average, at the end of the study). Furthermore, in nondiabetic patients there was also an earlier significant fall (within the first 4 h after the start of treatment with amiodarone, p < 0.001) in the heart rate values in comparison with diabetic patients, in whom a significant decrease (p < 0.001) was found only at the 4th day. A significant (p = 0.0004), more rapid onset of the antiarrhythmic response to the drug was found in nondiabetic patients (6.8 +/- 6.0 h) in comparison with diabetic patients (98.0 +/- 14.8 h). Our findings suggest that the antiarrhythmic effects of amiodarone in diabetic patients with uncontrolled atrial fibrilation or atrial flutter may be delayed in comparison with nondiabetic patients. This altered response may be (at least in part) due to the diabetic autonomic neuropathy. Our study indicates that the presence of diabetes mellitus always must be taken into account when patients are enrolled for large, prospective, randomized trials, planned to evaluate the antiarrhythmic effects of amiodarone given intravenously.

Association between temperature and death in residential populations in Shanghai

NASA Astrophysics Data System (ADS)

Hsia, L. B.; Lu, J. K.

1988-03-01

The study is focused on patterns of daily deaths in Shanghai for the period from 1 May 1979 to 30 April 1980. From May to September the deaths in all age groups are lower, but increase gradually from October and reach to a peak in February. This confirms results found in other countries, namely the death rate is increased in winter. The peak for the population aged over 70 is the highest of the three different age groups. Correlation analyses were carried out on three temperature parameters (daily minimum, maximum and mean temperatures) and six categories of death (heart disease, coronary heart disease, cerebrovascular disease, cancer, respiratory disease and total deaths). The results reveal that the average daily temperature is very significant for the six categories of death. There are three correlations: straight line relationship, parabolic relationship and exponential relationship. These different types arise from the different morbidity rates. Death from the different disease is also increased during days when the daily maximum temperature is over 35° C or the daily minimum temperature is below 0°C. This shows, in general, that days of extreme temperature lead to an increase in the death rate.

Physiologic responses to forward and retrograde simulated stair stepping.

PubMed

Ryan, P T; Plowman, S A; Ball, T E; Looney, M A

1994-07-01

This study compared the physiologic responses to forward and retrograde simulated stair stepping on the StairMaster 4000 PT. Twenty male subjects (mean age 23.65 +/- 1.63 years) volunteered for this study. Subjects completed a practice trial of 6 minutes of both forward and retrograde stepping at Level 5. Each experimental trial was divided into four 3-minute stages: Level 3, Level 5, Level 7, and Level 9. Heart rate, blood pressure, and rating of perceived exertion (RPE) were recorded during the second minute of each stage. Expired gases were analyzed and averaged over the last 2 minutes of each stage. Caloric expenditure and delta efficiency were later calculated. Data were analyzed using a 2 x 4 ANOVA (direction by level) and 2 x 3 ANOVA (for delta efficiency). Compared to forward responses, retrograde heart rates were significantly higher at Levels 7 and 9 (p < 0.01). Retrograde responses for RPE, metabolic equivalents (METS), and caloric expenditure were significantly higher at (p < 0.01) Levels 5, 7, and 9 when compared to forward responses. However, the results of this study show that these differences between forward and retrograde stepping are not practically meaningful.

Validation of heart rate extraction through an iPhone accelerometer.

PubMed

Kwon, Sungjun; Lee, Jeongsu; Chung, Gih Sung; Park, Kwang Suk

2011-01-01

Ubiquitous medical technology may provide advanced utility for evaluating the status of the patient beyond the clinical environment. The iPhone provides the capacity to measure the heart rate, as the iPhone consists of a 3-axis accelerometer that is sufficiently sensitive to perceive tiny body movements caused by heart pumping. In this preliminary study, an iPhone was tested and evaluated as the reliable heart rate extractor to use for medical purpose by comparing with reference electrocardiogram. By comparing the extracted heart rate from acquired acceleration data with the extracted one from ECG reference signal, iPhone functioning as the reliable heart rate extractor has demonstrated sufficient accuracy and consistency.

Assessment of differences between repeated pulse wave velocity measurements in terms of 'bias' in the extrapolated cardiovascular risk and the classification of aortic stiffness: is a single PWV measurement enough?

PubMed

Papaioannou, T G; Protogerou, A D; Nasothimiou, E G; Tzamouranis, D; Skliros, N; Achimastos, A; Papadogiannis, D; Stefanadis, C I

2012-10-01

Currently, there is no recommendation regarding the minimum number of pulse wave velocity (PWV) measurements to optimize individual's cardiovascular risk (CVR) stratification. The aim of this study was to examine differences between three single consecutive and averaged PWV measurements in terms of the extrapolated CVR and the classification of aortic stiffness as normal. In 60 subjects who referred for CVR assessment, three repeated measurements of blood pressure (BP), heart rate and PWV were performed. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and mean±s.d. of differences. The absolute differences between single and averaged PWV measurements were classified as: ≤0.25, 0.26-0.49, 0.50-0.99 and ≥1 m s(-1). A difference ≥0.5 m s(-1) (corresponding to 7.5% change in CVR, meta-analysis data from >12 000 subjects) was considered as clinically meaningful; PWV values (single or averaged) were classified as normal according to respective age-corrected normal values (European Network data). Kappa statistic was used to evaluate the agreement between classifications. PWV for the first, second and third measurement was 7.0±1.9, 6.9±1.9, 6.9±2.0 m s(-1), respectively (P=0.319); BP and heart rate did not vary significantly. A good reproducibility between single measurements was observed (ICC>0.94, s.d. ranged between 0.43 and 0.64 m s(-1)). A high percent with difference ≥0.5 m s(-1) was observed between: any pair of the three single PWV measurements (26.6-38.3%); the first or second single measurement and the average of the first and second (18.3%); any single measurement and the average of three measurements (10-20%). In only up to 5% a difference ≥0.5 m s(-1) was observed between the average of three and the average of any two PWV measurements. There was no significant agreement regarding PWV classification as normal between: the first or second measurement and the averaged PWV values. There was significant agreement in classification made by the average of the first two and the average of three PWV measurements (κ=0.85, P<0.001). Even when high reproducibility in PWV measurement is succeeded single measurements provide quite variable results in terms of the extrapolated CVR and the classification of aortic stiffness as normal. The average of two PWV measurements provides similar results with the average of three.

Effects of linear ablation at the isthmus between the tricuspid annulus and inferior vena cava for atrial flutter on autonomic nervous activity: analysis of heart rate variability.

PubMed

Li, Aiyan; Kuga, Keisuke; Suzuki, Akihiro; Endo, Masae; Niho, Bumpei; Enomoto, Mami; Kanemoto, Miyako; Yamaguchi, Iwao

2002-01-01

Heart rate is largely affected by the autonomic nervous system. However, little is known about the anatomic pathway of autonomic nerve fibers innervating the sinus node. The present study: (1) evaluates the effects of cavotricuspid isthmus ablation for common atrial flutter (AFL) on autonomic nervous function by using heart rate variability analysis, and (2) investigates the distribution of autonomic nerve pathways innervating the sinus node. Twelve patients with paroxysmal common atrial flutter who maintained sinus rhythm both before and after radiofrequency ablation were selected for the study. Holter ambulatory recordings were performed before and after (2.3 +/- 1.0 days) radiofrequency ablation of cavotricuspid isthmus. Heart rate and time domain (SDANN, rMSSD, pNN50) and frequency domain (low frequency (LF), high frequency (HF), LF/HF) analysis of heart rate variability were compared before and after ablation. Mean heart rate did not change significantly after ablation (59 +/- 6 vs 61 +/- 9 beats/min); parasympathetic indices of heart rate variability (SDANN, rMSSD, pNN50, HF) did not change significantly (110 +/- 37 vs 117 +/- 20 ms; 32 +/- 21 vs 28 +/- 9 ms; 4.8 +/- 0.9 vs 4.7 +/- 0.71n(ms2)); and sympathetic indices of heart rate variability (LF/HF) did not change significantly (1.1 +/- 0.2 vs 1.2 +/- 0.1). Cavotricuspid isthmus ablation for atrial flutter did not significantly change heart rate and heart rate variability because parasympathetic and sympathetic fibers innervating the sinus node are scarce in this region.

Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm.

PubMed

Pansini, Vittorio; Remy-Jardin, Martine; Tacelli, Nunzia; Faivre, Jean-Baptiste; Flohr, Thomas; Deken, Valérie; Duhamel, Alain; Remy, Jacques

2008-10-01

To evaluate the assessibility of coronary arteries in respiratory patients with high heart rates. This study was based on the comparative analysis of two paired populations of 54 patients with a heart rate >70 bpm evaluated with dual-source (group 1) and single-source (group 2) CT. The mean heart rate was 89.1 bpm in group 1 and 86.7 bpm in group 2 (P=0.26). The mean number of assessable segments per patient was significantly higher in group 1 compared to group 2 (P

Human Fetal Heart Rate Dishabituation between Thirty and Thirty-Two Weeks Gestation.

ERIC Educational Resources Information Center

Sandman, Curt A.; Wadhwa, Pathik; Hetrick, William; Porto, Manuel; Peeke, Harmon V. S.

1997-01-01

Examined the ability of 32-week human fetuses to learn and recall information. Found a significant heart rate habituation pattern for a series of vibroacoustic stimuli. After a single novel stimulus, the heart rate to stimulus 1 reemerged. Uterine contractions were not related to presentation of the novel stimulus or change in heart rate after the…

Rhesus monkey heart rate during exercise

NASA Technical Reports Server (NTRS)

Delorge, J.; Thach, J. S., Jr.

1972-01-01

Various schedules of reinforcement and their relation to heart rates of rhesus monkeys during exercise are described. All the reinforcement schedules produced 100 per cent or higher increments in the heart rates of the monkeys during exercise. Resting heart rates were generally much lower than those previously reported, which was attributed to the lack of physical restraint of the monkeys during recording.

Dynamic analysis of heart rate may predict subsequent ventricular tachycardia after myocardial infarction

NASA Technical Reports Server (NTRS)

Makikallio, T. H.; Seppanen, T.; Airaksinen, K. E.; Koistinen, J.; Tulppo, M. P.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1997-01-01

Dynamics analysis of RR interval behavior and traditional measures of heart rate variability were compared between postinfarction patients with and without vulnerability to ventricular tachyarrhythmias in a case-control study. Short-term fractal correlation of heart rate dynamics was better than traditional measures of heart rate variability in differentiating patients with and without life-threatening arrhythmias.

Design of heart rate monitor based on piezoelectric sensor using an Arduino

NASA Astrophysics Data System (ADS)

Setyowati, Veni; Muninggar, Jodelin; Shanti. N. A, Made R. S.

2017-01-01

Reading of result heart rate using an acoustic stethoscope needs a particular skill, quiet environment, and hearing sensitivity. This project had the purpose design of a user-friendly automatic heart rate monitor and especially in a noisy area which to eliminate problems and incorrect reading of result. The liquid crystal display shows a heart rate as a result of measurements. The design of the heart rate monitor has two main parts; the signal recorder that a piezoelectric sensor, a filter, and an amplifier as recorder. The second parts was Arduino microcontroller with reinforced. Besides, three supporting buttons provided as the manual switches, the ‘on’, the ‘start’, and ‘reset’ buttons. The values acquired from the heart rate monitor indicate that those were on the Vernier BPS-BTA value range. The measurement error factor of the heart rate monitor then compared to the Vernier BPS-BTA test device was 3.15%. Besides, the value of statistical independent-test indicates that there is no significant difference (P = 0.971) between the heart rate monitor device and the Vernier BPS-BTA. In conclusion, this device was ready to be used because it has almost the same accuracy with the standart device.

Opportunity for information search and the effect of false heart rate feedback.

PubMed

Barefoot, John C; Straub, Ronald B

2005-01-01

The role of information search in the attribution of physiological states was investigated by manipulating the subject's opportunity for information search following the presentation of false information about his heart-rate reactions to photographs of female nudes. Consistent with the self-persuasion hypothesis proposed by Valins, the rated attractiveness of the slides was not affected by the false heart-rate feedback for those subjects who were prevented from visually searching the slides. Those subjects who had ample opportunity to view the slides rated those slides accompanied by false information of a heart-rate change as more attractive than those slides which were not paired with a change in heart rate.

Identification of genomic loci associated with resting heart rate and shared genetic predictors with all-cause mortality.

PubMed

Eppinga, Ruben N; Hagemeijer, Yanick; Burgess, Stephen; Hinds, David A; Stefansson, Kari; Gudbjartsson, Daniel F; van Veldhuisen, Dirk J; Munroe, Patricia B; Verweij, Niek; van der Harst, Pim

2016-12-01

Resting heart rate is a heritable trait correlated with life span. Little is known about the genetic contribution to resting heart rate and its relationship with mortality. We performed a genome-wide association discovery and replication analysis starting with 19.9 million genetic variants and studying up to 265,046 individuals to identify 64 loci associated with resting heart rate (P < 5 × 10 -8 ); 46 of these were novel. We then used the genetic variants identified to study the association between resting heart rate and all-cause mortality. We observed that a genetically predicted resting heart rate increase of 5 beats per minute was associated with a 20% increase in mortality risk (hazard ratio 1.20, 95% confidence interval 1.11-1.28, P = 8.20 × 10 -7 ) translating to a reduction in life expectancy of 2.9 years for males and 2.6 years for females. Our findings provide evidence for shared genetic predictors of resting heart rate and all-cause mortality.

Genome-wide association studies and resting heart rate.

PubMed

Kilpeläinen, Tuomas O

Genome-wide association studies (GWASs) have revolutionized the search for genetic variants regulating resting heart rate. In the last 10years, GWASs have led to the identification of at least 21 novel heart rate loci. These discoveries have provided valuable insights into the mechanisms and pathways that regulate heart rate and link heart rate to cardiovascular morbidity and mortality. GWASs capture majority of genetic variation in a population sample by utilizing high-throughput genotyping chips measuring genotypes for up to several millions of SNPs across the genome in thousands of individuals. This allows the identification of the strongest heart rate associated signals at genome-wide level. While GWASs provide robust statistical evidence of the association of a given genetic locus with heart rate, they are only the starting point for detailed follow-up studies to locate the causal variants and genes and gain further insights into the biological mechanisms underlying the observed associations. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of competition on heart rate during kart driving: A field study.

PubMed

Matsumura, Kenta; Yamakoshi, Takehiro; Yamakoshi, Yasuhiro; Rolfe, Peter

2011-09-09

Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength.

The effect of competition on heart rate during kart driving: A field study

PubMed Central

2011-01-01

Background Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations. Findings The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min). Conclusions The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength. PMID:21906298

Management of heart transplant recipients: reference for primary care physicians.

PubMed

Kansara, Pranav; Kobashigawa, Jon A

2012-07-01

Heart transplantation is the treatment of choice for a select group of patients with end-stage heart failure. Survival rates have increased and complication rates have decreased due to better immunosuppressive agents, improvement in organ procurement and surgical technique, and overall increase in experience for performing heart transplantation. Involvement from primary care physicians is very important to optimize postoperative management of heart transplant recipients. In this article, we discuss the indications for heart transplantation, physiology of the denervated heart, the standard postoperative care of adult heart transplant recipients, and long-term complications. Primary care physicians must play an increasing role in the management of heart transplant recipients in the age of managed care and increasing survival rates.

Poster - Thur Eve - 26: Interfraction reproducibility of heart position during breast irradiation using Active Breathing Control.

PubMed

Comsa, D; Zhang, B; Mosely, D; Yeung, I

2012-07-01

The moderate deep-inspiration breath hold (mDIBH) technique using the Active Breathing Coordinator (ABC) from Elekta is used in our clinic to lower the heart dose during left breast irradiations. The purpose of this work was to investigate the interfraction reproducibility of the heart to chest distance during these treatments and to evaluate the dosimetric effect of any changes in the heart position. Daily CBCT images were available for 5 patients who had been treated with ABC tangents and a cavity boost. On these images, one-dimensional measurements of the distance between the heart and the chest wall were taken at two anatomical locations corresponding roughly with the location where the radiation field most likely intercepts the heart. The average change in this distance was interpreted as a shift of the heart position. To assess the effect of this shift on the delivered heart dose, the heart contours in the clinical plans of the corresponding patients were shifted towards the treatment field using standard Pinnacle tools. Although the ABC device allows good reproducibility of the volume of air held, this does not warrant reproducibility of heart position for all patients during treatment. The largest average heart shift extracted from CBCT images in this study was 6.2mm. The heart dose reconstructed using this shift for the corresponding patient also showed the largest effect. However, even in the presence of a systematic heart shift of this magnitude, the ABC plan still showed superior heart dose reduction compared to the free-breathing plan. © 2012 American Association of Physicists in Medicine.

Prototype early warning system for heart disease detection using Android Application.

PubMed

Zennifa, Fadilla; Fitrilina; Kamil, Husnil; Iramina, Keiji

2014-01-01

Heart Disease affects approximately 70 million people worldwide where most people do not even know the symptoms. This research examines the prototype of early warning system for heart disease by android application. It aims to facilitate users to early detect heart disease which can be used independently. To build the application in android phone, variable centered intelligence rule system (VCIRS) as decision makers and pulse sensor - Arduino as heart rate detector were applied in this study. Moreover, in Arduino, the heart rate will become an input for symptoms in Android Application. The output of this system is the conclusion statement of users diagnosed with either coronary heart disease, hypertension heart disease, rheumatic heart disease or do not get any kind of heart disease. The result of diagnosis followed by analysis of the value of usage variable rate (VUR) rule usage rate (RUR) and node usage rate (NUR) that shows the value of the rule that will increase when the symptoms frequently appear. This application was compared with the medical analysis from 35 cases of heart disease and it showed concordance between diagnosis from android application and expert diagnosis of the doctors.

How heart rate variability affects emotion regulation brain networks.

PubMed

Mather, Mara; Thayer, Julian

2018-02-01

Individuals with high heart rate variability tend to have better emotional well-being than those with low heart rate variability, but the mechanisms of this association are not yet clear. In this paper, we propose the novel hypothesis that by inducing oscillatory activity in the brain, high amplitude oscillations in heart rate enhance functional connectivity in brain networks associated with emotion regulation. Recent studies using daily biofeedback sessions to increase the amplitude of heart rate oscillations suggest that high amplitude physiological oscillations have a causal impact on emotional well-being. Because blood flow timing helps determine brain network structure and function, slow oscillations in heart rate have the potential to strengthen brain network dynamics, especially in medial prefrontal regulatory regions that are particularly sensitive to physiological oscillations.

Children's Heart Rate Reactivity Responses to Three School Tasks.

ERIC Educational Resources Information Center

Sharpley, Christopher F.; And Others

1989-01-01

Investigated effects of 3 routine classroom arithmetic and reading tasks upon the heart rate reactivity of 30 fifth grade children. Results indicated that some children showed large increases in heart rates during the three tasks, and that these children should be considered at risk for coronary heart disease. (Author/TE)

Problem Behavior and Heart Rate Reactivity in Adopted Adolescents: Longitudinal and Concurrent Relations

ERIC Educational Resources Information Center

Bimmel, Nicole; van IJzendoorn, Marinus H.; Bakermans-Kranenburg, Marian J.; Juffer, Femmie; De Geus, Eco J. C.

2008-01-01

The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate…

Tachycardia

MedlinePlus

... normal while at rest. It's normal for your heart rate to rise during exercise or as a physiological ... the heart or both while at rest. Your heart rate is controlled by electrical signals sent across heart ...

The Relationship Between Heart Rate Reserve and Oxygen Uptake Reserve in Heart Failure Patients on Optimized and Non-Optimized Beta-Blocker Therapy

PubMed Central

Carvalho, Vitor Oliveira; Guimarães, Guilherme Veiga; Bocchi, Edimar Alcides

2008-01-01

BACKGROUND The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients either on non-optimized or off beta-blocker therapy is known to be unreliable. The aim of this study was to evaluate the relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients receiving optimized and non-optimized beta-blocker treatment during a treadmill cardiopulmonary exercise test. METHODS A total of 27 sedentary heart failure patients (86% male, 50±12 years) on optimized beta-blocker therapy with a left ventricle ejection fraction of 33±8% and 35 sedentary non-optimized heart failure patients (75% male, 47±10 years) with a left ventricle ejection fraction of 30±10% underwent the treadmill cardiopulmonary exercise test (Naughton protocol). Resting and peak effort values of both the percentage of oxygen consumption reserve and percentage of heart rate reserve were, by definition, 0 and 100, respectively. RESULTS The heart rate slope for the non-optimized group was derived from the points 0.949±0.088 (0 intercept) and 1.055±0.128 (1 intercept), p<0.0001. The heart rate slope for the optimized group was derived from the points 1.026±0.108 (0 intercept) and 1.012±0.108 (1 intercept), p=0.47. Regression linear plots for the heart rate slope for each patient in the non-optimized and optimized groups revealed a slope of 0.986 (almost perfect) for the optimized group, but the regression analysis for the non-optimized group was 0.030 (far from perfect, which occurs at 1). CONCLUSION The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in patients on optimized beta-blocker therapy was reliable, but this relationship was unreliable in non-optimized heart failure patients. PMID:19060991

Revision of orthovoltage chest wall treatment using Monte Carlo simulations.

PubMed

Zeinali-Rafsanjani, B; Faghihi, R; Mosleh-Shirazi, M A; Mosalaei, A; Hadad, K

2017-01-01

Given the high local control rates observed in breast cancer patients undergoing chest wall irradiation by kilovoltage x-rays, we aimed to revisit this treatment modality by accurate calculation of dose distributions using Monte Carlo simulation. The machine components were simulated using the MCNPX code. This model was used to assess the dose distribution of chest wall kilovoltage treatment in different chest wall thicknesses and larger contour or fat patients in standard and mid sternum treatment plans. Assessments were performed at 50 and 100 cm focus surface distance (FSD) and different irradiation angles. In order to evaluate different plans, indices like homogeneity index, conformity index, the average dose of heart, lung, left anterior descending artery (LAD) and percentage target coverage (PTC) were used. Finally, the results were compared with the indices provided by electron therapy which is a more routine treatment of chest wall. These indices in a medium chest wall thickness in standard treatment plan at 50 cm FSD and 15 degrees tube angle was as follows: homogeneity index 2.57, conformity index 7.31, average target dose 27.43 Gy, average dose of heart, lung and LAD, 1.03, 2.08 and 1.60 Gy respectively and PTC 11.19%. Assessments revealed that dose homogeneity in planning target volume (PTV) and conformity between the high dose region and PTV was poor. To improve the treatment indices, the reference point was transferred from the chest wall skin surface to the center of PTV. The indices changed as follows: conformity index 7.31, average target dose 60.19 Gy, the average dose of heart, lung and LAD, 3.57, 6.38 and 5.05 Gy respectively and PTC 55.24%. Coverage index of electron therapy was 89% while it was 22.74% in the old orthovoltage method and also the average dose of the target was about 50 Gy but in the given method it was almost 30 Gy. The results of the treatment study show that the optimized standard and mid sternum treatment for different chest wall thicknesses is with 50 cm FSD and zero (vertical) tube angle, while in large contour patients, it is with 100 cm FSD and zero tube angle. Finally, chest wall kilovoltage and electron therapies were compared, which revealed that electron therapy produces a better dose distribution than kilovoltage therapy.

Ambient temperature and biomarkers of heart failure: a repeated measures analysis.

PubMed

Wilker, Elissa H; Yeh, Gloria; Wellenius, Gregory A; Davis, Roger B; Phillips, Russell S; Mittleman, Murray A

2012-08-01

Extreme temperatures have been associated with hospitalization and death among individuals with heart failure, but few studies have explored the underlying mechanisms. We hypothesized that outdoor temperature in the Boston, Massachusetts, area (1- to 4-day moving averages) would be associated with higher levels of biomarkers of inflammation and myocyte injury in a repeated-measures study of individuals with stable heart failure. We analyzed data from a completed clinical trial that randomized 100 patients to 12 weeks of tai chi classes or to time-matched education control. B-type natriuretic peptide (BNP), C-reactive protein (CRP), and tumor necrosis factor (TNF) were measured at baseline, 6 weeks, and 12 weeks. Endothelin-1 was measured at baseline and 12 weeks. We used fixed effects models to evaluate associations with measures of temperature that were adjusted for time-varying covariates. Higher apparent temperature was associated with higher levels of BNP beginning with 2-day moving averages and reached statistical significance for 3- and 4-day moving averages. CRP results followed a similar pattern but were delayed by 1 day. A 5°C change in 3- and 4-day moving averages of apparent temperature was associated with 11.3% [95% confidence interval (CI): 1.1, 22.5; p = 0.03) and 11.4% (95% CI: 1.2, 22.5; p = 0.03) higher BNP. A 5°C change in the 4-day moving average of apparent temperature was associated with 21.6% (95% CI: 2.5, 44.2; p = 0.03) higher CRP. No clear associations with TNF or endothelin-1 were observed. Among patients undergoing treatment for heart failure, we observed positive associations between temperature and both BNP and CRP-predictors of heart failure prognosis and severity.

Heart rate and outcome in heart failure with reduced ejection fraction: Differences between atrial fibrillation and sinus rhythm-A CIBIS II analysis.

PubMed

Mulder, Bart A; Damman, Kevin; Van Veldhuisen, Dirk J; Van Gelder, Isabelle C; Rienstra, Michiel

2017-09-01

Heart rate has been associated with prognosis in patients with heart failure with reduced ejection fraction (HFREF) and sinus rhythm; whether this also holds true in patients with atrial fibrillation (AF) is unknown. To evaluate cardiac rhythm and baseline heart rate and the influence of outcome in patients with HFREF enrolled in the Cardiac Insufficiency Bisoprolol Study II. In total, 2539 patients were stratified according to their baseline heart rhythm (AF or sinus rhythm) and into quartiles of heart rate (≤70 bpm, 71-78 bpm, 79-90 bpm, and >90 bpm). The primary outcome was all-cause mortality. Mean follow-up was 1.3 years. Mean age was 61 years, mean left ventricular ejection fraction was 28%, and 80% were male. A total of 521 (21%) patients had AF at baseline. The risk associated with all-cause mortality for each 5 bpm increase in heart rate in patients with sinus rhythm (hazard ratio [HR]: 1.06, 95% confidence interval [CI]: 1.01-1.11, P = 0.012) was significantly different from those with AF (HR: 1.00, 95% CI: 0.94-1.07, P = 0.90, P for interaction = 0.041). The risk associated with higher heart rate in sinus rhythm was primarily attributable to excess risk in the highest quartile (HR: 1.64, 95% CI: 1.18-2.30, P = 0.003). Allocation to bisoprolol did not modify the interaction between heart rate, rhythm and outcome. In HFREF patients with AF, a higher heart rate is not associated with increased event rates in contrast to HFREF patients with sinus rhythm. © 2017 Wiley Periodicals, Inc.

Heart rate at first postdischarge visit and outcomes in patients with heart failure.

PubMed

Kim, Tae-Hun; Kim, Hyungseop; Kim, In-Cheol; Yoon, Hyuck-Jun; Park, Hyoung-Seob; Cho, Yun-Kyeong; Nam, Chang-Wook; Han, Seongwook; Hur, Seung-Ho; Kim, Yoon-Nyun

2018-07-01

Heart rate control is important to prevent adverse outcomes in patients with heart failure (HF). However, postdischarge activity may worsen heart rate control, resulting in readmission. This study aimed to explore the implications of the heart rate differences between discharge and the first outpatient visit (D-O diff). We retrospectively identified 458 patients (male: 46%; mean age: 72 years) discharged after HF. The heart rates at admission, discharge and first outpatient visit were analysed. The primary outcome was a composite of cardiovascular (CV) death and readmission of non-fatal myocardial infarction (MI), non-fatal stroke or non-fatal HF over a mean follow-up of 16 months. During follow-up, the clinical outcomes were noted in 223 patients (49%): HF, 199; stroke, 9; MI, 6; CV death, 9. The heart rate at the first outpatient visit (r=-0.311, P<0.001) and D-O diff (r=0.416, P<0.001) showed a better correlation with the time-to-clinical event than the heart rate at admission or discharge. The events group displayed a pronounced heart rate increase (13 beats/min) from discharge to the first outpatient visit compared with the event-free group (a decrease of 2 beats/min). A decrease less than -15 in the D-O diff showed a 4.5-fold risk of clinical outcomes during follow-up (P<0.001). A decreased D-O diff was related to the adverse outcomes of HF. The failure of heart rate control within more than 15 beats/min at the first outpatient visit was an independent factor for CV events. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Heart rate at admission is a predictor of in-hospital mortality in patients with acute coronary syndromes: Results from 58 European hospitals: The European Hospital Benchmarking by Outcomes in acute coronary syndrome Processes study.

PubMed

Jensen, Magnus T; Pereira, Marta; Araujo, Carla; Malmivaara, Anti; Ferrieres, Jean; Degano, Irene R; Kirchberger, Inge; Farmakis, Dimitrios; Garel, Pascal; Torre, Marina; Marrugat, Jaume; Azevedo, Ana

2018-03-01

The purpose of this study was to investigate the relationship between heart rate at admission and in-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Consecutive ACS patients admitted in 2008-2010 across 58 hospitals in six participant countries of the European Hospital Benchmarking by Outcomes in ACS Processes (EURHOBOP) project (Finland, France, Germany, Greece, Portugal and Spain). Cardiogenic shock patients were excluded. Associations between heart rate at admission in categories of 10 beats per min (bpm) and in-hospital mortality were estimated by logistic regression in crude models and adjusting for age, sex, obesity, smoking, hypertension, diabetes, known heart failure, renal failure, previous stroke and ischaemic heart disease. In total 10,374 patients were included. In both STEMI and NSTE-ACS patients, a U-shaped relationship between admission heart rate and in-hospital mortality was found. The lowest risk was observed for heart rates between 70-79 bpm in STEMI and 60-69 bpm in NSTE-ACS; risk of mortality progressively increased with lower or higher heart rates. In multivariable models, the relationship persisted but was significant only for heart rates >80 bpm. A similar relationship was present in both patients with or without diabetes, above or below age 75 years, and irrespective of the presence of atrial fibrillation or use of beta-blockers. Heart rate at admission is significantly associated with in-hospital mortality in patients with both STEMI and NSTE-ACS. ACS patients with admission heart rate above 80 bpm are at highest risk of in-hospital mortality.

Heart position variability during voluntary moderate deep inspiration breath-hold radiotherapy for breast cancer determined by repeat CBCT scans.

PubMed

van Haaren, Paul; Claassen-Janssen, Fiere; van de Sande, Ingrid; Boersma, Liesbeth; van der Sangen, Maurice; Hurkmans, Coen

2017-08-01

Voluntary moderate deep inspiration breath hold (vmDIBH) in left-sided breast cancer radiotherapy reduces cardiac dose. The aim of this study was to investigate heart position variability in vmDIBH using CBCT and to compare this variability with differences in heart position between vmDIBH and free breathing (FB). For 50 patients initial heart position with respect to the field edge (HP-FE) was measured on a vmDIBH planning CT scan. Breath-hold was monitored using an in-house developed vertical plastic stick. On pre-treatment CBCT scans, heart position variability with respect to the field edge (Δ HP-FE ) was measured, reflecting heart position variability when using an offline correction protocol. After registering the CBCT scan to the planning CT, heart position variability with respect to the chest wall (Δ HP-CW ) was measured, reflecting heart position variability when using an online correction protocol. As a control group, vmDIBH and FB computed tomography (CT) scans were acquired for 30 patients and registering both scans on the chest wall. For 34 out of 50 patients, the average HP-FE and HP-CW increased over the treatment course in comparison to the planning CT. Averaged over all patients and all treatment fractions, the Δ HP-FE and the Δ HP-CW was 0.8±4.2mm (range -9.4-+10.6mm) and 1.0±4.4mm (range -8.3-+10.4mm) respectively. The average gain in heart to chest wall distance was 11.8±4.6mm when using vmDIBH instead of FB. In conclusion, substantial variability in heart position using vmDIBH was observed during the treatment course. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Bi-ventricular finite element model of right ventricle overload in the healthy rat heart.

PubMed

Masithulela, Fulufhelo

2016-11-25

The recognition of RV overpressure is critical to human life, as this may signify morbidity and mortality. Right ventricle (RV) dysfunction is understood to have an impact on the performance of the left ventricle (LV), but the mechanisms remain poorly understood. It is understood that ventricular compliance has the ability to affect cardiac performance. In this study, a bi-ventricular model of the rat heart was used in preference to other, single-ventricle models. Finite element analysis (FEA) of the bi-ventricular model provides important information on the function of the healthy heart. The passive myocardium was modelled as a nearly incompressible, hyperelastic, transversely isotropic material using finite element (FE) methods. Bi-ventricular geometries of healthy rat hearts reconstructed from magnetic resonance images were imported in Abaqus©. In simulating the normal passive filling of the rat heart, pressures of 4.8 kPa and 0.0098 kPa were applied to the inner walls of the LV and RV respectively. In addition, to simulate the overpressure of the RV, pressures of 2.4 kPa and 4.8 kPa were applied to the endocardial walls of the LV and RV respectively. As boundary conditions, the circumferential and longitudinal displacements at the base were set to zero. The radial displacements at the base were left free. The results show that the average circumferential stress at the mid-wall in the overloaded model increased from 2.8 kPa to 18.2 kPa. The average longitudinal stress increased from 1.5 kPa to 9.7 kPa. Additionally, in the radial direction, the average stress increased from 0.1 kPa to 0.6 kPa in the mid-wall. The average circumferential strain was found to be 0.138 and 0.100 on the endocardium of the over pressured and healthy model respectively. The average circumferential stress at the epicardium, mid-wall and endocardium in the case of a normal heart is 10 times lower than in the overloaded heart model. The finite analysis method is able to provide insights into the behaviour of the over pressured model (myocardium). In the overloaded model the high stresses and strains were observed on the septal wall. The bi-ventricular model was shown to provide useful information relating to the over pressured ventricle. The possible heart dysfunction may be attributable to high stress and strain in the over pressured heart.

Heart Rate Recovery, Physical Activity Level, and Functional Status in Subjects With COPD.

PubMed

Morita, Andrea A; Silva, Laís K O; Bisca, Gianna W; Oliveira, Joice M; Hernandes, Nidia A; Pitta, Fabio; Furlanetto, Karina C

2018-05-15

A normal heart rate reflects the balance between the sympathetic and parasympathetic autonomic nervous system. When the difference between heart rate at the end of an exercise test and after 1 min of recovery, known as the 1-min heart rate recovery, is ≤ 12 beats/min, this may indicate an abnormal delay. We sought to compare physical activity patterns and subjects' functional status with COPD with or without delayed 1-min heart rate recovery after the 6-min walk test (6MWT). 145 subjects with COPD (78 men, median [interquartile range (IQR)] age 65 [60-73] y, body mass index 25 [21-30] kg/m 2 , FEV 1 45 ± 15% predicted) were underwent the following assessments: spirometry, 6MWT, functional status, and physical activity in daily life (PADL). A delayed heart rate recovery of 1 min was defined as ≤ 12 beats/min. Subjects with delayed 1-min heart rate recovery walked a shorter distance in the 6MWT compared to subjects without delayed heart rate recovery (median [IQR] 435 [390-507] m vs 477 [425-515] m, P = .01; 81 [71-87] vs 87 [79-98]% predicted, P = .002). Regarding PADL, subjects with delayed heart rate recovery spent less time in the standing position (mean ± SD 185 ± 89 min vs 250 ± 107 min, P = .002) and more time in sedentary positions (472 ± 110 min vs 394 ± 129 min, P = .002). Scores based on the self-care domain of the London Chest Activity of Daily Living questionnaire and the activity domain of the Pulmonary Functional Status and Dyspnea questionnaire were also worse in the group with delayed heart rate recovery (6 ± 2 points vs 5 ± 2 points; P = .039 and 29 ± 24 points vs 19 ± 17 points; P = .037, respectively). Individuals with COPD who exhibit delayed 1-min heart rate recovery after the 6MWT exhibited worse exercise capacity as well as a more pronounced sedentary lifestyle and worse functional status than those without delayed heart rate recovery. Despite its assessment simplicity, heart rate recovery after the 6MWT can be further explored as a promising outcome in COPD. Copyright © 2018 by Daedalus Enterprises.

Making the Most of the "Daphnia" Heart Rate Lab: Optimizing the Use of Ethanol, Nicotine & Caffeine

ERIC Educational Resources Information Center

Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey

2010-01-01

Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…

Leptin decreases heart rate associated with increased ventricular repolarization via its receptor.

PubMed

Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H; Hull, Robert; Davis, Mary; Yu, Han-Gang

2015-11-15

Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1-30 μg/kg) decreased resting heart rate; at high doses (150-300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03-0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. Copyright © 2015 the American Physiological Society.

Leptin decreases heart rate associated with increased ventricular repolarization via its receptor

PubMed Central

Lin, Yen-Chang; Huang, Jianying; Hileman, Stan; Martin, Karen H.; Hull, Robert; Davis, Mary

2015-01-01

Leptin has been proposed to modulate cardiac electrical properties via β-adrenergic receptor activation. The presence of leptin receptors and adipocytes in myocardium raised a question as to whether leptin can directly modulate cardiac electrical properties such as heart rate and QT interval via its receptor. In this work, the role of local direct actions of leptin on heart rate and ventricular repolarization was investigated. We identified the protein expression of leptin receptors at cell surface of sinus node, atrial, and ventricular myocytes isolated from rat heart. Leptin at low doses (0.1–30 μg/kg) decreased resting heart rate; at high doses (150–300 μg/kg), leptin induced a biphasic effect (decrease and then increase) on heart rate. In the presence of high-dose propranolol (30 mg/kg), high-dose leptin only reduced heart rate and sometimes caused sinus pauses and ventricular tachycardia. The leptin-induced inhibition of resting heart rate was fully reversed by leptin antagonist. Leptin also increased heart rate-corrected QT interval (QTc), and leptin antagonist did not. In isolated ventricular myocytes, leptin (0.03–0.3 μg/ml) reversibly increased the action potential duration. These results supported our hypothesis that in addition to indirect pathway via sympathetic tone, leptin can directly decrease heart rate and increase QT interval via its receptor independent of β-adrenergic receptor stimulation. During inhibition of β-adrenergic receptor activity, high concentration of leptin in myocardium can cause deep bradycardia, prolonged QT interval, and ventricular arrhythmias. PMID:26408544

Low Blood Pressure

MedlinePlus

... to low blood pressure are an abnormally low heart rate ( bradycardia ), problems with heart valves , heart attack and ... occurred. Is low blood pressure related to low heart rate? Find out . This content was last reviewed October ...