21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use in...

21 CFR 892.1410 - Nuclear electrocardiograph synchronizer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear electrocardiograph synchronizer. 892.1410... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1410 Nuclear electrocardiograph synchronizer. (a) Identification. A nuclear electrocardiograph synchronizer is a device intended for use in...

Utility of 12-lead electrocardiogram for differentiating paroxysmal supraventricular tachycardias in dogs.

PubMed

Santilli, R A; Perego, M; Crosara, S; Gardini, F; Bellino, C; Moretti, P; Spadacini, G

2008-01-01

The 12-lead surface ECG is validated for differentiating supraventricular tachycardias (SVT) in humans. Despite the description of SVT in veterinary medicine, no studies have analyzed the electrocardiographic features of this type of arrhythmias in dogs. To describe the specific electrocardiographic criteria used to differentiate the most common SVT in dogs. Twenty-three dogs examined at Clinica Veterinaria Malpensa for SVT with the mechanism documented by electrophysiologic studies (EPS). Twelve-lead electrocardiographic variables obtained from 14 dogs with orthodromic atrioventricular reciprocating tachycardia (OAVRT) and 9 dogs with focal atrial tachycardia (FAT) were compared. Dogs with FAT had faster heart rates (278 +/- 62 versus 229 +/- 42 bpm; P= .049) and less QRS alternans (33 versus 86%; P= .022). P waves appeared during tachycardia in 22 dogs, with a superior axis in 100% of OAVRT and 22% of FAT (P < .001). OAVRT was characterized by a shorter RP interval (85.0 +/- 16.8 versus 157.1 +/- 37.3 ms; P < .001) and smaller RP/PR ratio (0.60 +/- 0.18 versus 1.45 +/- 0.52; P < .001). Repolarization anomalies were present in 64% of OAVRT and no FAT (P < .001). Multivariate analysis identified QRS alternans and a positive P wave in aVR during tachycardia as independent predictors of arrhythmia type. Electrocardiographic criteria used in people for differentiating SVT can also be applied in dogs.

Electrical and Structural Substrate of Arrhythmogenic Right Ventricular Cardiomyopathy Determined Using Noninvasive Electrocardiographic Imaging and Late Gadolinium Magnetic Resonance Imaging.

PubMed

Andrews, Christopher M; Srinivasan, Neil T; Rosmini, Stefania; Bulluck, Heerajnarain; Orini, Michele; Jenkins, Sharon; Pantazis, Antonis; McKenna, William J; Moon, James C; Lambiase, Pier D; Rudy, Yoram

2017-07-01

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a significant cause of sudden cardiac death in the young. Improved noninvasive assessment of ARVC and better understanding of the disease substrate are important for improving patient outcomes. We studied 20 genotyped ARVC patients with a broad spectrum of disease using electrocardiographic imaging (a method for noninvasive cardiac electrophysiology mapping) and advanced late gadolinium enhancement cardiac magnetic resonance scar imaging. Compared with 20 healthy controls, ARVC patients had longer ventricular activation duration (median, 52 versus 42 ms; P =0.007) and prolonged mean epicardial activation-recovery intervals (a surrogate for local action potential duration; median, 275 versus 241 ms; P =0.014). In these patients, we observed abnormal and varied epicardial activation breakthrough locations and regions of nonuniform conduction and fractionated electrograms. Nonuniform conduction and fractionated electrograms were present in the early concealed phase of ARVC. Electrophysiological abnormalities colocalized with late gadolinium enhancement scar, indicating a relationship with structural disease. Premature ventricular contractions were common in ARVC patients with variable initiation sites in both ventricles. Premature ventricular contraction rate increased with exercise, and within anatomic segments, it correlated with prolonged repolarization, electric markers of scar, and late gadolinium enhancement (all P <0.001). Electrocardiographic imaging reveals electrophysiological substrate properties that differ in ARVC patients compared with healthy controls. A novel mechanistic finding is the presence of repolarization abnormalities in regions where ventricular ectopy originates. The results suggest a potential role for electrocardiographic imaging and late gadolinium enhancement in early diagnosis and noninvasive follow-up of ARVC patients. © 2017 American Heart Association, Inc.

Influence of Mobile Phones on the Quality of ECG Signal Acquired by Medical Devices

NASA Astrophysics Data System (ADS)

Buczkowski, T.; Janusek, D.; Zavala-Fernandez, H.; Skrok, M.; Kania, M.; Liebert, A.

2013-10-01

Health aspects of the use of radiating devices, like mobile phones, are still a public concern. Stand-alone electrocardiographic systems and those built-in, more sophisticated, medical devices have become a standard tool used in everyday medical practice. GSM mobile phones might be a potential source of electromagnetic interference (EMI) which may affect reliability of medical appliances. Risk of such event is particularly high in places remote from GSM base stations in which the signal received by GSM mobile phone is weak. In such locations an increase in power of transmitted radio signal is necessary to enhance quality of the communication. In consequence, the risk of interference of electronic devices increases because of the high level of EMI. In the present paper the spatial, temporal, and spectral characteristics of the interference have been examined. The influence of GSM mobile phone on multilead ECG recordings was studied. It was observed that the electrocardiographic system was vulnerable to the interference generated by the GSM mobile phone working with maximum transmit power and in DTX mode when the device was placed in a distance shorter than 7.5 cm from the ECG electrode located on the surface of the chest. Negligible EMI was encountered at any longer distance.

21 CFR 870.2340 - Electrocardiograph.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrocardiograph. 870.2340 Section 870.2340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2340 Electrocardiograph. (a...

21 CFR 870.2340 - Electrocardiograph.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrocardiograph. 870.2340 Section 870.2340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2340 Electrocardiograph. (a...

21 CFR 870.2360 - Electrocardiograph electrode.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrocardiograph electrode. 870.2360 Section 870.2360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2360 Electrocardiograph...

21 CFR 870.2360 - Electrocardiograph electrode.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrocardiograph electrode. 870.2360 Section 870.2360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2360 Electrocardiograph...

Vectorcardiogram

NASA Technical Reports Server (NTRS)

Costello, M.

1973-01-01

System measures electrocardiographic potentials to produce precise quantitative measurement of changes that occur in individual's cardiac function. System is rugged, built to sustain extremes of temperature, pressure, humidity, shock, and vibration. It can also be used in pure oxygen environment without danger of combustion.

[Diagnostic performance of surface electrocardiogram in early detection of chagasic cardiomyopathy].

PubMed

Bochard-Villanueva, Bruno; Estornell-Erill, Jordi; Fabregat-Andrés, Óscar; García-González, Pilar; Morell-Cabedo, Salvador; Ridocci-Soriano, Francisco

2015-03-15

Contrast-enhanced cardiac magnetic resonance imaging (CMR) allows early detection of myocardial involvement by Trypanosoma cruzi infection. The aim of our study was to assess the diagnostic performance of the surface electrocardiogram (ECG) in the early detection of Chagas' cardiomyopathy (CCM) compared with CMR. We included 43 asymptomatic patients (30 women, 42 ± 9.8 years), diagnosed of Chagas disease. The sample was divided into 2 groups according to the presence (n=17) or absence (n=26) of electrocardiographic abnormalities. All patients underwent CMR and late gadolinium enhancement (LGE) was used as a marker of early myocardial involvement. Six (14%) patients had a LGE significantly higher in the group who had electrocardiographic abnormalities (29 vs. 4%, P<.05). With CMR as the method of reference, the ECG had a sensitivity of 83% and a negative predictive value of 96% to detect CCM. ECG is a useful, inexpensive and globally available tool for the screening of CCM in asymptomatic patients but with proven myocardial involvement in CMR. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

ECG-ViEW II, a freely accessible electrocardiogram database

PubMed Central

Park, Man Young; Lee, Sukhoon; Jeon, Min Seok; Yoon, Dukyong; Park, Rae Woong

2017-01-01

The Electrocardiogram Vigilance with Electronic data Warehouse II (ECG-ViEW II) is a large, single-center database comprising numeric parameter data of the surface electrocardiograms of all patients who underwent testing from 1 June 1994 to 31 July 2013. The electrocardiographic data include the test date, clinical department, RR interval, PR interval, QRS duration, QT interval, QTc interval, P axis, QRS axis, and T axis. These data are connected with patient age, sex, ethnicity, comorbidities, age-adjusted Charlson comorbidity index, prescribed drugs, and electrolyte levels. This longitudinal observational database contains 979,273 electrocardiograms from 461,178 patients over a 19-year study period. This database can provide an opportunity to study electrocardiographic changes caused by medications, disease, or other demographic variables. ECG-ViEW II is freely available at http://www.ecgview.org. PMID:28437484

The Role of Transmural Repolarization Gradient in the Inversion of Cardiac Electric Field: Model Study of ECG in Hypothermia.

PubMed

Arteyeva, Natalia V; Azarov, Jan E

2017-01-01

The changes in ventricular repolarization gradients lead to significant alterations of the electrocardiographic body surface T waves up to the T wave inversion. However, the contribution of a specific gradient remains to be elucidated. The objective of the present investigation was to study the role of the transmural repolarization gradient in the inversion of the body surface T wave with a mathematical model of the hypothermia-induced changes of ventricular repolarization. By means of mathematical simulation, we set the hypothermic action potential duration (APD) distribution on the rabbit ventricular epicardium as it was previously experimentally documented. Then the parameters of the body surface potential distribution were tested with the introduction of different scenarios of the endocardial and epicardial APD behavior in hypothermia resulting in the unchanged, reversed or enlarged transmural repolarization gradient. The reversal of epicardial repolarization gradients (apicobasal, anterior-posterior and interventricular) caused the inversion of the T waves regardless of the direction of the transmural repolarization gradient. However, the most realistic body surface potentials were obtained when the endocardial APDs were not changed under hypothermia while the epicardial APDs prolonged. This produced the reversed and increased transmural repolarization gradient in absolute magnitude. The body surface potentials simulated under the unchanged transmural gradient were reduced in comparison to those simulated under the reversed transmural gradient. The simulations demonstrated that the transmural repolarization gradient did not play a crucial role in the cardiac electric field inversion under hypothermia, but its magnitude and direction contribute to the T wave amplitude. © 2016 Wiley Periodicals, Inc.

ECG by mobile technologies.

PubMed

Guzik, Przemyslaw; Malik, Marek

Mobile electrocardiographs consist of three components: a mobile device (e.g. a smartphone), an electrocardiographic device or accessory, and a mobile application. Mobile platforms are small computers with sufficient computational power, good quality display, suitable data storage, and several possibilities of data transmission. Electrocardiographic electrodes and sensors for mobile use utilize unconventional materials, e.g. rubber, e-textile, and inkjet-printed nanoparticle electrodes. Mobile devices can be handheld, worn as vests or T-shirts, or attached to patient's skin as biopatches. Mobile electrocardiographic devices and accessories may additionally record other signals including respiratory rate, activity level, and geolocation. Large-scale clinical studies that utilize electrocardiography are easier to conduct using mobile technologies and the collected data are suitable for "big data" processing. This is expected to reveal phenomena so far inaccessible by standard electrocardiographic techniques. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrocardiographic Findings in Brazilian Adults without Heart Disease: ELSA-Brasil.

PubMed

Pinto, Marcelo Martins; Brant, Luisa C C; Padilha-da-Silva, José Luiz; Foppa, Murilo; Lotufo, Paulo A; Mill, José Geraldo; Vasconcelo-Silva, Paulo R; Almeida, Maria da Conceição C; Barreto, Sandhi Maria; Ribeiro, Antônio Luiz Pinho

2017-11-01

The electrocardiogram (ECG) is widely used in population-based studies. However, there are few studies on electrocardiographic findings in Latin America and in Brazil. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) comprised 15,105 participants (35-74 years) from six Brazilian capitals. To describe electrocardiographic findings in Brazilian adults without heart disease, stratified by sex, age and race/skin color. Cross-sectional study with baseline data of 11,094 adults (44.5% men) without heart disease from ELSA-Brasil. The ECGs were recorded with the Burdick Atria 6100 machine and stored at the Pyramis System. ECG analysis was automatically performed using the Glasgow University software. A descriptive analysis of heart rate (HR), P, QRS and T waves' duration, PR and QT intervals, and P, R and T axes was performed. After stratification by sex, race/color and age, the groups were compared by the Wilcoxon and Kruskal-Wallis test at a significance level of 5%. Linear regression models were used to evaluate the behavior of electrocardiographic parameters over age. Major electrocardiographic abnormalities defined by the Minnesota code were manually revised. Medians values of the electrocardiographic parameters were different between men and women: HR 63 vs. 66 bpm, PR 164 vs.158 ms, QT corrected 410 vs. 421 ms, QRS duration 92 vs. 86 ms, P-wave duration 112 vs. 108 ms, P-wave axis 54 vs. 57 degrees, R-wave axis 35 vs. 39 degrees, T-wave axis 39 vs. 45 degrees (p < 0.001 for all). The 2nd and the 98th percentiles of each variable were also obtained, and graphs were constructed to illustrate the behavior of the electrocardiographic findings over age of participants stratified by sex and race/skin color. The values for the electrocardiographic measurements herein described can be used as reference for Brazilian adults free of heart disease, stratified by sex. Our results suggest that self-reported race/skin color have no significant influence on electrocardiographic parameters.

Electrocardiographic Findings in Brazilian Adults without Heart Disease: ELSA-Brasil

PubMed Central

Pinto Filho, Marcelo Martins; Brant, Luisa C. C.; Padilha-da-Silva, José Luiz; Foppa, Murilo; Lotufo, Paulo A.; Mill, José Geraldo; Vasconcelo-Silva, Paulo R.; Almeida, Maria da Conceição C.; Barreto, Sandhi Maria; Ribeiro, Antônio Luiz Pinho

2017-01-01

Background The electrocardiogram (ECG) is widely used in population-based studies. However, there are few studies on electrocardiographic findings in Latin America and in Brazil. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) comprised 15,105 participants (35-74 years) from six Brazilian capitals. Objectives To describe electrocardiographic findings in Brazilian adults without heart disease, stratified by sex, age and race/skin color. Methods Cross-sectional study with baseline data of 11,094 adults (44.5% men) without heart disease from ELSA-Brasil. The ECGs were recorded with the Burdick Atria 6100 machine and stored at the Pyramis System. ECG analysis was automatically performed using the Glasgow University software. A descriptive analysis of heart rate (HR), P, QRS and T waves’ duration, PR and QT intervals, and P, R and T axes was performed. After stratification by sex, race/color and age, the groups were compared by the Wilcoxon and Kruskal-Wallis test at a significance level of 5%. Linear regression models were used to evaluate the behavior of electrocardiographic parameters over age. Major electrocardiographic abnormalities defined by the Minnesota code were manually revised. Results Medians values of the electrocardiographic parameters were different between men and women: HR 63 vs. 66 bpm, PR 164 vs.158 ms, QT corrected 410 vs. 421 ms, QRS duration 92 vs. 86 ms, P-wave duration 112 vs. 108 ms, P-wave axis 54 vs. 57 degrees, R-wave axis 35 vs. 39 degrees, T-wave axis 39 vs. 45 degrees (p < 0.001 for all). The 2nd and the 98th percentiles of each variable were also obtained, and graphs were constructed to illustrate the behavior of the electrocardiographic findings over age of participants stratified by sex and race/skin color. Conclusions The values for the electrocardiographic measurements herein described can be used as reference for Brazilian adults free of heart disease, stratified by sex. Our results suggest that self-reported race/skin color have no significant influence on electrocardiographic parameters. PMID:28977056

Lithium Batteries

Science.gov Websites

medical devices including electrocardiographs. In addition, new "textured" cathodes have been the potential medical uses of the batteries, including transdermal applications for heart regulation .' -Edited excerpt from Medical Applications of Non-medical Research Resources with Additional Information

RTOS kernel in portable electrocardiograph

NASA Astrophysics Data System (ADS)

Centeno, C. A.; Voos, J. A.; Riva, G. G.; Zerbini, C.; Gonzalez, E. A.

2011-12-01

This paper presents the use of a Real Time Operating System (RTOS) on a portable electrocardiograph based on a microcontroller platform. All medical device digital functions are performed by the microcontroller. The electrocardiograph CPU is based on the 18F4550 microcontroller, in which an uCOS-II RTOS can be embedded. The decision associated with the kernel use is based on its benefits, the license for educational use and its intrinsic time control and peripherals management. The feasibility of its use on the electrocardiograph is evaluated based on the minimum memory requirements due to the kernel structure. The kernel's own tools were used for time estimation and evaluation of resources used by each process. After this feasibility analysis, the migration from cyclic code to a structure based on separate processes or tasks able to synchronize events is used; resulting in an electrocardiograph running on one Central Processing Unit (CPU) based on RTOS.

21 CFR 884.2600 - Fetal cardiac monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... ascertain fetal heart activity during pregnancy and labor. The device is designed to separate fetal heart signals from maternal heart signals by analyzing electrocardiographic signals (electrical potentials generated during contraction and relaxation of heart muscle) obtained from the maternal abdomen with...

21 CFR 884.2600 - Fetal cardiac monitor.

Code of Federal Regulations, 2013 CFR

2013-04-01

... ascertain fetal heart activity during pregnancy and labor. The device is designed to separate fetal heart signals from maternal heart signals by analyzing electrocardiographic signals (electrical potentials generated during contraction and relaxation of heart muscle) obtained from the maternal abdomen with...

21 CFR 884.2600 - Fetal cardiac monitor.

Code of Federal Regulations, 2012 CFR

2012-04-01

... ascertain fetal heart activity during pregnancy and labor. The device is designed to separate fetal heart signals from maternal heart signals by analyzing electrocardiographic signals (electrical potentials generated during contraction and relaxation of heart muscle) obtained from the maternal abdomen with...

21 CFR 884.2600 - Fetal cardiac monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... ascertain fetal heart activity during pregnancy and labor. The device is designed to separate fetal heart signals from maternal heart signals by analyzing electrocardiographic signals (electrical potentials generated during contraction and relaxation of heart muscle) obtained from the maternal abdomen with...

21 CFR 884.2600 - Fetal cardiac monitor.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ascertain fetal heart activity during pregnancy and labor. The device is designed to separate fetal heart signals from maternal heart signals by analyzing electrocardiographic signals (electrical potentials generated during contraction and relaxation of heart muscle) obtained from the maternal abdomen with...

Electrocardiographic left ventricular hypertrophy criteria and ambulatory blood pressure monitoring parameters in adults.

PubMed

Gómez-Marcos, Manuel A; Recio-Rodríguez, Jose I; Patino-Alonso, María C; Agudo-Conde, Cristina; Fernandez-Alonso, Carmen; Martinez Vizcaino, Vicente; Cantera, Carlos Martin; Guenaga-Saenz, Nahia; González-Viejo, Natividad; García-Ortiz, Luis

2014-03-01

To examine the relationship between ambulatory blood pressure monitoring parameters (ABPM) and electrocardiographic criteria for left-ventricular hypertrophy (LVH) in adults. This study analyzed 1,544 subjects from the EVIDENT study (mean age = 55 ± 14 years; 61% women). A standard electrocardiograph (ECG) and 10 criteria were used to detect LVH. Office and ABPM were performed, and we analyzed 24-hour systolic blood pressure (SBP) and diastolic blood pressure (DBP), percentage of time awake with SBP ≥135 mm Hg, percentage of time asleep with SBP ≥120 mm Hg, and central aortic blood pressure. LVH according to some electrocardiographic criteria was found in 11.30% of the patients (16.60% of men and 7.70% of women). The patients with LVH were older; had higher values for office, 24-hour and, central aortic blood pressure; were more likely to be men; and had a higher prevalence of obesity, diabetes, and antihypertensive or lipid-lowering drug use. In the logistic regression analysis, the association between the parameters of ABPM and LVH, after adjusting for age, sex, body mass index, and heart rate, remained statistically significant. Twenty-four hour blood pressure, the percentage of time with elevated awake and asleep SBPs, and the central systolic blood pressure are related to the presence of LVH as determined by ECG in adults. These results indicate the potential importance of the monitoring and control of different 24-hour parameters of blood pressure in addition to the standard clinic blood pressure with respect to the development of LVH. ClinicalTrials.gov identifier NCT01325064.

ELECTROCARDIOGRAPHIC ABNORMALITIES AMONG MEXICAN AMERICANS: CORRELATIONS WITH DIABETES, OBESITY, AND THE METABOLIC SYNDROME.

PubMed

Queen, Saulette R; Smulevitz, Beverly; Rentfro, Anne R; Vatcheva, Kristina P; Kim, Hyunggun; McPherson, David D; Hanis, Craig L; Fisher-Hoch, Susan P; McCormick, Joseph B; Laing, Susan T

2012-04-01

Resting ischemic electrocardiographic abnormalities have been associated with cardiovascular mortality. Simple markers of abnormal autonomic tone have also been associated with diabetes, obesity, and the metabolic syndrome in some populations. Data on these electrocardiographic abnormalities and correlations with coronary risk factors are lacking among Mexican Americans wherein these conditions are prevalent. This study aimed to evaluate the prevalent resting electrocardiographic abnormalities among community-dwelling Mexican Americans, and correlate these findings with coronary risk factors, particularly diabetes, obesity, and the metabolic syndrome. Study subjects (n=1280) were drawn from the Cameron County Hispanic Cohort comprised of community-dwelling Mexican Americans living in Brownsville, Texas at the United States-Mexico border. Ischemic electrocardiographic abnormalities were defined as presence of ST/T wave abnormalities suggestive of ischemia, abnormal Q waves, and left bundle branch block. Parameters that reflect autonomic tone, such as heart rate-corrected QT interval and resting heart rate, were also measured. Ischemic electrocardiographic abnormalities were more prevalent among older persons and those with hypertension, diabetes, obesity, and the metabolic syndrome. Subjects in the highest quartiles of QTc interval and resting heart rate were also more likely to be diabetic, hypertensive, obese, or have the metabolic syndrome. Among Mexican Americans, persons with diabetes, obesity, and the metabolic syndrome were more likely to have ischemic electrocardiographic abnormalities, longer QTc intervals, and higher resting heart rates. A resting electrocardiogram can play a complementary role in the comprehensive evaluation of cardiovascular risk in this minority population.

Modeling of Electrocardiograph Telediagnosing System Based on Petri Net

NASA Astrophysics Data System (ADS)

Hu, Wensong; Li, Ming; Li, Lan

This paper analyzed the characteristics of the electrocardiograph telediagnosing system. Firstly, we introduce the system and Petri nets. Secondly, we built a topological diagram of this system. Then we use Petri nets to show the physical process of this system. Finally, we verified the model of the electrocardiograph telediagnosing system. With the help of model based on Petri nets, we analyzed the system performance and feasibility.

Effectiveness of electrocardiographic guidance in CVAD tip placement.

PubMed

Walker, Graham; Chan, Raymond J; Alexandrou, Evan; Webster, Joan; Rickard, Claire

International standard practice for the correct confirmation of the central venous access device is the chest X-ray. The intracavitary electrocardiogram-based insertion method is radiation-free, and allows real-time placement verification, providing immediate treatment and reduced requirement for post-procedural repositioning. Relevant databases were searched for prospective randomised controlled trials (RCTs) or quasi RCTs that compared the effectiveness of electrocardiogram-guided catheter tip positioning with placement using surface-anatomy-guided insertion plus chest X-ray confirmation. The primary outcome was accurate catheter tip placement. Secondary outcomes included complications, patient satisfaction and costs. Five studies involving 729 participants were included. Electrocardiogram-guided insertion was more accurate than surface anatomy guided insertion (odds ratio: 8.3; 95% confidence interval (CI) 1.38; 50.07; p=0.02). There was a lack of reporting on complications, patient satisfaction and costs. The evidence suggests that intracavitary electrocardiogram-based positioning is superior to surface-anatomy-guided positioning of central venous access devices, leading to significantly more successful placements. This technique could potentially remove the requirement for post-procedural chest X-ray, especially during peripherally inserted central catheter (PICC) line insertion.

Right ventricular involvement in patients with inferior myocardial infarction, correlation of electrocardiographic findings with echocardiography data.

PubMed

Javed, Sumbul; Rajani, Ali Raza; Govindaswamy, Pushparani; Radaideh, Ghazi Ahmed; Abubaraka, Harb Ahmed; Qureshi, Tariq Ilyas; Arshad, Hassaan Bin

2017-03-01

To determine the right ventricular involvement in patients with inferior myocardial infarction by echocardiography in relation to electrocardiographic findings. This observational, prospective study was conducted at Rashid Hospital, Dubai, the United Arab Emirates, from January to September 2013, and comprised patients with inferior myocardial infarction. All patients aged above 18 years were included. Right ventricular myocardial infarction was defined by the electrocardiographic criteria of > 1mV ST elevation in V4R-V5R leads. RV infarction was assessed on echocardiography by fractional area change, tricuspid annular plane systolic excursion and tricuspid annular systolic velocity by tissue Doppler imaging. SPSS 21 was used for data analysis. Of the 73 patients, there were 68(93%) men and 5(7%) women. The three modalities used to assess the right ventricular infarction showed right ventricular involvement in 36(49.3%) cases by fractional area change, 28(38.4%) cases by tricuspid annular plane systolic excursion and 31(42.5%) cases by tissue Doppler imaging in patients with inferior myocardial infarction. Tissue Doppler imaging and right ventricular function showed low degree of negative correlation (p=0.16) while the correlation between tricuspid annular plane systolic excursion and right ventricular function showed significant positive correlation (p<0.0001). Assessment of right ventricular infarction by echocardiography helped to diagnose right ventricular infarction in greater number of cases compared to surface electrocardiogram.

Hyperkalemia.

PubMed

Hollander-Rodriguez, Joyce C; Calvert, James F

2006-01-15

Hyperkalemia is a potentially life-threatening metabolic problem caused by inability of the kidneys to excrete potassium, impairment of the mechanisms that move potassium from the circulation into the cells, or a combination of these factors. Acute episodes of hyperkalemia commonly are triggered by the introduction of a medication affecting potassium homeostasis; illness or dehydration also can be triggers. In patients with diabetic nephropathy, hyperkalemia may be caused by the syndrome of hyporeninemic hypoaldosteronism. The presence of typical electrocardiographic changes or a rapid rise in serum potassium indicates that hyperkalemia is potentially life threatening. Urine potassium, creatinine, and osmolarity should be obtained as a first step in determining the cause of hyperkalemia, which directs long-term treatment. Intravenous calcium is effective in reversing electrocardiographic changes and reducing the risk of arrhythmias but does not lower serum potassium. Serum potassium levels can be lowered acutely by using intravenous insulin and glucose, nebulized beta2 agonists, or both. Sodium polystyrene therapy, sometimes with intravenous furosemide and saline, is then initiated to lower total body potassium levels.

[Influence of coke oven emissions on workers' blood pressure and electrocardiographic findings].

PubMed

Liang, J J; Yi, G L; Mao, G S; Wang, D M; Dai, X Y

2016-09-20

Objective: To investigate the influence of coke oven emissions on workers' blood pressure and electrocardiographic findings, and to provide a basis for the prevention and treatment of cardiovascular diseases. Methods: The concentration of coke oven emissions at the bottom, side, and top of coke ovens was determined in a coking plant. A total of 406 coke oven workers were enrolled as exposure group and 201 office staff members were enrolled as control group. Blood pressure and electrocardiographic findings were compared between the two groups, and the multivariate logistic regression analysis was performed to analyze the influencing factors for hypertension and abnormal electrocardiographic findings. Results: The concentration of coke oven emissions was the highest at the top of coke ovens, followed by the side and bottom of coke ovens, and there was a significant difference between the exposure group and the control group ( P <0.01). The exposure group had significantly higher detection rates of hypertension, abnormal electrocardiographic findings, and abnormal chest X-ray findings than the control group ( P <0.05). The logistic regression analysis showed that high concentration of coke oven emission and age were risk factors for hypertension and abnormal electrocardiographic findings ( P <0.05). The workers exposed to high-concentration coke oven emissions were more likely to experience hypertension and abnormal electrocardiographic findings than those exposed to low-concentration coke oven emissions ( OR =1.7 and 1.9). Conclusion: Besides lung injury, coke oven emissions also have adverse effects on the cardiovascular system. Therefore, more effective measures are needed to protect the health of coke oven workers.

Usefulness of Electrocardiographic QT Interval to Predict Left Ventricular Diastolic Dysfunction

PubMed Central

Wilcox, Jane E.; Rosenberg, Jonathan; Vallakati, Ajay; Gheorghiade, Mihai; Shah, Sanjiv J.

2013-01-01

Whether a normal electrocardiogram excludes left ventricular (LV) diastolic dysfunction (DD) and whether electrocardiographic parameters are associated with DD is unknown. We therefore sought to investigate the relation between electrocardiographic parameters and DD. We first evaluated 75 consecutive patients referred for echocardiography for clinical suspicion of heart failure (phase 1). Electrocardiography and comprehensive echocardiography were performed on all patients and were analyzed separately in a blinded fashion. Receiver operating characteristic curves and multivariate regression analyses were used to determine which electrocardiographic parameters were most closely associated with DD. Next, we prospectively validated our results in 100 consecutive, unselected patients undergoing echocardiography (phase 2). In phase 1 of our study, the mean age was 59 ± 14 years, 41% were women, 31% had coronary disease, 53% had hypertension, and 25% had diabetes. The mean ejection fraction was 54 ± 15%, and 64% had DD. Of all the electrocardiographic parameters, the QTc interval was most closely associated with DD. QTc was inversely associated with E′ velocity (r = −0.54, p <0.0001), and the area under the receiver operating characteristic curve for QTc as a predictor of DD was 0.82. QTc prolongation was independently associated with reduced E′ velocity (p = 0.021 after adjustment for age, gender, medications, QRS duration, and ejection fraction). In phase 2 of our study QTc was the electrocardiographic parameter most associated with reduced E′ velocity (435 ± 31 vs 419 ± 24 ms; p = 0.004), confirming our phase 1 study findings. In conclusion, QTc prolongation was the electrocardiographic marker most predictive of DD and was independently associated with DD. PMID:21907948

[Experience in the use of equipment for ECG system analysis in municipal polyclinics].

PubMed

Bondarenko, A A

2006-01-01

Two electrocardiographs, an analog-digital electrocardiograph with preliminary analog filtering of signal and a smart cardiograph implemented as a PC-compatible device without preliminary analog filtering, are considered. Advantages and disadvantages of ECG systems based on artificial intelligence are discussed. ECG interpretation modes provided by the two electrocardiographs are considered. The reliability of automatic ECG interpretation is assessed. Problems of rational use of automated ECG processing systems are discussed.

Computer aided exercise electrocardiographic testing and coronary arteriography in patients with angina pectoris and with myocardial infarction.

PubMed Central

Angelhed, J E; Bjurö, T I; Ejdebäck, J; Selin, K; Schlossman, D; Griffith, L S; Bergstrand, R; Vedin, A; Wilhelmsson, C

1984-01-01

A set of electrocardiographic criteria for the diagnosis of coronary artery disease was evaluated in two different groups of patients examined by computer aided 12 lead exercise electrocardiographic stress testing and coronary arteriography. One group consisted of patients with severe angina pectoris and the other of patients who had suffered a myocardial infarction three years before the study. Angiographically determined categories of patients could be identified with satisfactory precision by the electrocardiographic criteria under test in the patients with angina pectoris but not in those with infarction. A new method of classifying patients on the basis of data from coronary arteriography improved the correlation with ST segment analysis compared with conventional classification. PMID:6743432

Comparative Electrocardiographic, Autonomic, and Systemic Inflammatory Responses to Soy Biodiesel and Petroleum Diesel Emissions in Rats

EPA Science Inventory

CONTEXT: 8iodiesel fuel represents an alternative to high particulate matter (PM)-emitting petroleum-based diesel fuels, yet uncertainty remains regarding potential biodiesel combustion emission health impacts.OBJECTIVE: The purpose of this study was to compare cardiovascular res...

[Left ventricular hypertrophy in black African subjects with artery hypertension: Results of a cross-sectional survey conducted in semi-rural area in Senegal].

PubMed

Mbaye, A; Dodo, B; Ngaïde, A A; Sy, N F; Babaka, K; Mingou, J S; Faye, M; Niang, K; Sarr, S A; Dioum, M; Bodian, M; Ndiaye, M B; Kane, A D; Ndour-Mbaye, M; Diao, M; Diack, B; Kane, M; Diagne-Sow, D; Thiaw, I; Kane, A

2017-09-01

To assess the prevalence of left ventricular hypertrophy according to electrocardiographic and echocardiographic criteria among hypertensive patients living in semi-rural Senegalese area. According to the World Health Organization STEPSwise approach, we conducted, in November 2012, a cross-sectional and exhaustive study in the population aged at least 35 years old and living for at least six months in the semi-rural area of Guéoul. We researched electrocardiographic and echocardiographic left ventricular hypertrophy in hypertensive subjects. Data were analyzed with SPSS 18.0 software version. The significance level was agreed for a value of P<0.05. We examined 1411 subjects aged on average of 48.5±12.7 years. In total, 654 subjects were hypertensive and screening of left ventricular hypertrophy (LVH) was effective in 515 of them. According to Sokolow-Lyon index, 86 subjects (16.7%) presented electrocardiographic LVH, more frequently in men (P=0.002). According to Cornell index and Cornell product, LVH was founded respectively in 66 (12.8%) and 52 subjects (10.1%), more frequently in female (P=0.0001; P=0.004). It was more common in grade 3 of hypertension however criteria. In echocardiography, prevalence of LVH was 2.2% (13 cases) according to the left ventricular mass, 9.3% (48 cases) according to the left ventricular mass indexed to body surface area and 8.2% (42 cases) according to the left ventricular mass indexed to height 2.7 . LVH was significantly correlated with the electrocardiographic LVH according to Sokolow-Lyon index (P<0.0001) and the grade 3 of hypertension (P=0.003). Although rare in hypertensive Senegalese living in semi-rural area, left ventricular hypertrophy is correlated with severity of grade of hypertension. Screening by electrocardiogram will allow better follow-up of these hypertensive subjects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Two markers in predicting the cardiovascular events in patients with polycystic ovary syndrome: increased P-wave and QT dispersion.

PubMed

Akdag, S; Cim, N; Yildizhan, R; Akyol, A; Ozturk, F; Babat, N

2015-09-01

Polycystic ovary syndrome (PCOS) is a prevalent disease with many potential long-term cardiovascular risks. P-wave dispersion (Pdis) and QT dispersion (QTdis) have been shown to be noninvasive electrocardiographic predictors for development of cardiac arrhythmias. In this study we aimed to search Pdis and QTdis parameters in patients with PCOS. The study included 82 patients with PCOS and 74 age- and sex-matched healthy controls. Baseline 12-lead electrocardiographic and transthoracic echocardiographic measurements were evaluated. P-wave maximum duration (Pmax), P-wave minimum duration (Pmin), Pdis, QT interval, heart rate-corrected QT dispersion and QTdis were calculated by two cardiologists. Patients wirh PCOS had significantly higher QT dispersion (49.5 ± 14.1 vs. 37.9 ± 12.6 ms, p < 0.001), and P wave dispersion (54.2 ± 11.4 vs. 45.9 ± 10.1 ms, p < 0.001) than the controls. Serum testosterone and estradiol levels was correlated with the Pdis (r = 0.677, p < 0.001 and r = 0.415, p < 0.001 respectively) and QTdis (r = 0.326, p < 0.001 and r = 0.321, p < 0.001 respectively). Pdis and QTdis are simple and useful electrocardiographic markers which may be used in the prediction of the risk of adverse cardiovascular events in PCOS patients.

Heart Rate Monitor

NASA Technical Reports Server (NTRS)

1984-01-01

In the mid 70's, NASA saw a need for a long term electrocardiographic electrode suitable for use on astronauts. Heart Rate Inc.'s insulated capacitive electrode is constructed of thin dielectric film applied to stainless steel surface, originally developed under a grant by Texas Technical University. HRI, Inc. was awarded NASA license and continued development of heart rate monitor for use on exercise machines for physical fitness and medical markets.

Fitzsimons General Hospital, Physiotherapy & Electrocardiograph Department Building, North of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Fitzsimons General Hospital, Physiotherapy & Electrocardiograph Department Building, North of Building No. 516, East of corridor connecting Building No. 511 to Building No. 515, Aurora, Adams County, CO

The value of electrocardiography for differential diagnosis in wide QRS complex tachycardia.

PubMed

Sousa, Pedro A; Pereira, Salomé; Candeias, Rui; de Jesus, Ilídio

2014-03-01

Correct diagnosis in wide QRS complex tachycardia remains a challenge. Differential diagnosis between ventricular and supraventricular tachycardia has important therapeutic and prognostic implications, and although data from clinical history and physical examination may suggest a particular origin, it is the 12-lead surface electrocardiogram that usually enables this differentiation. Since 1978, various electrocardiographic criteria have been proposed for the differential diagnosis of wide complex tachycardias, particularly the presence of atrioventricular dissociation, and the axis, duration and morphology of QRS complexes. Despite the wide variety of criteria, diagnosis is still often difficult, and errors can have serious consequences. To reduce such errors, several differential diagnosis algorithms have been proposed since 1991. However, in a small percentage of wide QRS tachycardias the diagnosis remains uncertain and in these the wisest decision is to treat them as ventricular tachycardias. The authors' objective was to review the main electrocardiographic criteria and differential diagnosis algorithms of wide QRS tachycardia. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Continuous ECG Monitoring in Patients With Acute Coronary Syndrome or Heart Failure: EASI Versus Gold Standard.

PubMed

Lancia, Loreto; Toccaceli, Andrea; Petrucci, Cristina; Romano, Silvio; Penco, Maria

2018-05-01

The purpose of the study was to compare the EASI system with the standard 12-lead surface electrocardiogram (ECG) for the accuracy in detecting the main electrocardiographic parameters (J point, PR, QT, and QRS) commonly monitored in patients with acute coronary syndromes or heart failure. In this observational comparative study, 253 patients who were consecutively admitted to the coronary care unit with acute coronary syndrome or heart failure were evaluated. In all patients, two complete 12-lead ECGs were acquired simultaneously. A total of 6,072 electrocardiographic leads were compared (3,036 standard and 3,036 EASI). No significant differences were found between the investigate parameters of the two measurement methods, either in patients with acute coronary syndrome or in those with heart failure. This study confirmed the accuracy of the EASI system in monitoring the main ECG parameters in patients admitted to the coronary care unit with acute coronary syndrome or heart failure.

Inverse electrocardiographic transformations: dependence on the number of epicardial regions and body surface data points.

PubMed

Johnston, P R; Walker, S J; Hyttinen, J A; Kilpatrick, D

1994-04-01

The inverse problem of electrocardiography, the computation of epicardial potentials from body surface potentials, is influenced by the desired resolution on the epicardium, the number of recording points on the body surface, and the method of limiting the inversion process. To examine the role of these variables in the computation of the inverse transform, Tikhonov's zero-order regularization and singular value decomposition (SVD) have been used to invert the forward transfer matrix. The inverses have been compared in a data-independent manner using the resolution and the noise amplification as endpoints. Sets of 32, 50, 192, and 384 leads were chosen as sets of body surface data, and 26, 50, 74, and 98 regions were chosen to represent the epicardium. The resolution and noise were both improved by using a greater number of electrodes on the body surface. When 60% of the singular values are retained, the results show a trade-off between noise and resolution, with typical maximal epicardial noise levels of less than 0.5% of maximum epicardial potentials for 26 epicardial regions, 2.5% for 50 epicardial regions, 7.5% for 74 epicardial regions, and 50% for 98 epicardial regions. As the number of epicardial regions is increased, the regularization technique effectively fixes the noise amplification but markedly decreases the resolution, whereas SVD results in an increase in noise and a moderate decrease in resolution. Overall the regularization technique performs slightly better than SVD in the noise-resolution relationship. There is a region at the posterior of the heart that was poorly resolved regardless of the number of regions chosen. The variance of the resolution was such as to suggest the use of variable-size epicardial regions based on the resolution.

Electocardiographic findings in adult Nigerians with sickle cell anaemia.

PubMed

Oguanobi, N I; Onwubere, B J C; Ike, S O; Anisiuba, B C; Ejim, E C; Ibegbulam, O G

2010-09-01

Cardiovascular system abnormalities are common causes of morbidity and mortality in sickle cell anaemia. The study aims at determining the pattern of electrocardiographic changes in adult Nigerian sickle cell anaemia patients. A descriptive cross sectional study was done on sixty sickle cell anaemia patients seen at the adult sickle cell clinic of University of Nigeria Teaching Hospital (UNTH) Enugu, and sixty age and sex matched normal controls. All the subjects had clinical evaluation as well as electrocardiographic examination. The mean heart rate, P-wave duration, P-wave dispersion, PR interval, QRS duration, QRS dispersion, QTc interval and QTc dispersion were significantly higher in the patients than in the control group. Electrocardiographic abnormalities identified by this study were: left ventricular hypertrophy (75%; 1.7%), left atrial enlargement (40%; 0%), biventricular hypertrophy (11%; 0), ST-segment elevation (10%; 0%) and increased P-wave and QTc dispersions. ST segment elevation was found more in patients with moderate and severe anaemia (P= 0.02, Spearman correlation r= 0.342; P= 0.007), Sickle cell anaemia is associated with significant electrocardiographic abnormalities. Further prospective studies are recommended to evaluate the prognostic significance of the electrocardiographic intervals dispersion on the long term disease outcome in sickle cell anaemia.

A Novel Lead Configuration for Optimal Spatio-Temporal Detection of Intracardiac Repolarization Alternans

PubMed Central

Weiss, Eric H.; Merchant, Faisal M.; d’Avila, Andre; Foley, Lori; Reddy, Vivek Y.; Singh, Jagmeet P.; Mela, Theofanie; Ruskin, Jeremy N.; Armoundas, Antonis A.

2011-01-01

Background Electrical alternans is a pattern of variation in the shape of electrocardiographic waveform that occurs every other beat. In humans, alternation in ventricular repolarization, known as repolarization alternans (RA), has been associated with increased vulnerability to ventricular tachycardia/fibrillation and sudden cardiac death. Methods and Results This study investigates the spatio-temporal variability of intracardiac RA and its relationship to body surface RA in an acute myocardial ischemia model in swine. We developed a real-time multi-channel repolarization signal acquisition, display and analysis system to record electrocardiographic signals from catheters in the right ventricle, coronary sinus, left ventricle, and epicardial surface prior to and following circumflex coronary artery balloon occlusion. We found that RA is detectable within 4 minutes following the onset ischemia, and is most prominently seen during the first half of the repolarization interval. Ischemia-induced RA was detectable on unipolar and bipolar leads (both in near- and far-field configurations) and on body surface leads. Far-field bipolar intracardiac leads were more sensitive for RA detection than body surface leads, with the probability of body surface RA detection increasing as the number of intracardiac leads detecting RA increased, approaching 100% when at least three intracardiac leads detected RA. We developed a novel, clinically-applicable intracardiac lead system based on a triangular arrangement of leads spanning the right ventricular (RV) and coronary sinus (CS) catheters which provided the highest sensitivity for intracardiac RA detection when compared to any other far-field bipolar sensing configurations (p < 0.0001). Conclusions In conclusion, intracardiac alternans, a complex spatio-temporal phenomenon associated with arrhythmia susceptibility and sudden cardiac death, can be reliably detected through a novel triangular RV-CS lead configuration. PMID:21430127

Hypokalemia-induced pseudoischemic electrocardiographic changes and quadriplegia.

PubMed

Mirijello, Antonio; Rinninella, Emanuele; De Leva, Francesca; Tosoni, Alberto; Vassallo, Gabriele; Antonelli, Mariangela; Addolorato, Giovanni; Landolfi, Raffaele

2014-03-01

Hypokalemia is a common biochemical abnormality. Severe hypokalemia can produce cardiac rhythm alterations and neurologic manifestations. Early detection and treatment allow clinician to prevent morbidity and mortality from cardiac arrhythmias and respiratory failure. Here, we describe a case of severe hypokalemia inducing pseudoischemic electrocardiographic (ECG) alterations and quadriplegia, in a patient affected by chronic diarrhea. Electrocardiographic alterations and neurologic manifestations completely disappeared after potassium replacement; however, prolonged potassium supplementation was required to achieve the normalization of plasmatic potassium levels. Consecutive figures show ECG improvement until normalization of ECG findings.

Atrial fibrillation detected by continuous electrocardiographic monitoring using implantable loop recorder to prevent stroke in individuals at risk (the LOOP study): Rationale and design of a large randomized controlled trial.

PubMed

Diederichsen, Søren Zöga; Haugan, Ketil Jørgen; Køber, Lars; Højberg, Søren; Brandes, Axel; Kronborg, Christian; Graff, Claus; Holst, Anders Gaarsdal; Nielsen, Jonas Bille; Krieger, Derk; Svendsen, Jesper Hastrup

2017-05-01

Atrial fibrillation (AF) increases the rate of stroke 5-fold, and AF-related strokes have a poorer prognosis compared with non-AF-related strokes. Atrial fibrillation and stroke constitute an intensifying challenge, and health care organizations are calling for awareness on the topic. Previous studies have demonstrated that AF is often asymptomatic and consequently undiagnosed. The implantable loop recorder (ILR) allows for continuous, long-term electrocardiographic monitoring with daily transmission of arrhythmia information, potentially leading to improvement in AF detection and stroke prevention. The LOOP study is an investigator-initiated, randomized controlled trial with 6,000 participants randomized 3:1 to a control group or to receive an ILR with continuous electrocardiographic monitoring. Participants are identified from Danish registries and are eligible for inclusion if 70years or older and previously diagnosed as having at least one of the following conditions: hypertension, diabetes mellitus, heart failure, or previous stroke. Exclusion criteria include history of AF and current oral anticoagulation treatment. When an AF episode lasting ≥6minutes is detected, oral anticoagulation will be initiated according to guidelines. Expected follow-up is 4years. The primary end point is time to stroke or systemic embolism, whereas secondary end points include time to AF diagnosis and death. The LOOP study will evaluate health benefits and cost-effectiveness of ILR as a screening tool for AF to prevent stroke in patients at risk. Secondary objectives include identification of risk factors for the development of AF and characterization of arrhythmias in the population. The trial holds the potential to influence the future of stroke prevention. Copyright © 2017 Elsevier Inc. All rights reserved.

Exertional headache and coronary ischemia despite normal electrocardiographic stress testing.

PubMed

Cutrer, F Michael; Huerter, Karina

2006-01-01

Exertional headaches may under certain conditions reflect coronary ischemia. We report the case of a patient seen in a neurology referral practice whose exertional headaches, even in the face of two normal electrocardiographic stress tests and in the absence of underlying chest pain were the sole symptoms of coronary ischemia as detected by Tc-99m Sestamibi testing SPECT stress testing. Stent placement resulted in complete resolution of headaches. Exertional headache in the absence of chest pain may reflect underlying symptomatic coronary artery disease (CAD) even when conventional electrocardiographic stress testing does not indicate ischemia.

Comparison of automated measurements of electrocardiographic intervals and durations by computer-based algorithms of digital electrocardiographs.

PubMed

Kligfield, Paul; Badilini, Fabio; Rowlandson, Ian; Xue, Joel; Clark, Elaine; Devine, Brian; Macfarlane, Peter; de Bie, Johan; Mortara, David; Babaeizadeh, Saeed; Gregg, Richard; Helfenbein, Eric D; Green, Cynthia L

2014-02-01

Automated measurements of electrocardiographic (ECG) intervals are widely used by clinicians for individual patient diagnosis and by investigators in population studies. We examined whether clinically significant systematic differences exist in ECG intervals measured by current generation digital electrocardiographs from different manufacturers and whether differences, if present, are dependent on the degree of abnormality of the selected ECGs. Measurements of RR interval, PR interval, QRS duration, and QT interval were made blindly by 4 major manufacturers of digital electrocardiographs used in the United States from 600 XML files of ECG tracings stored in the US FDA ECG warehouse and released for the purpose of this study by the Cardiac Safety Research Consortium. Included were 3 groups based on expected QT interval and degree of repolarization abnormality, comprising 200 ECGs each from (1) placebo or baseline study period in normal subjects during thorough QT studies, (2) peak moxifloxacin effect in otherwise normal subjects during thorough QT studies, and (3) patients with genotyped variants of congenital long QT syndrome (LQTS). Differences of means between manufacturers were generally small in the normal and moxifloxacin subjects, but in the LQTS patients, differences of means ranged from 2.0 to 14.0 ms for QRS duration and from 0.8 to 18.1 ms for the QT interval. Mean absolute differences between algorithms were similar for QRS duration and QT intervals in the normal and in the moxifloxacin subjects (mean ≤6 ms) but were significantly larger in patients with LQTS. Small but statistically significant group differences in mean interval and duration measurements and means of individual absolute differences exist among automated algorithms of widely used, current generation digital electrocardiographs. Measurement differences, including QRS duration and the QT interval, are greatest for the most abnormal ECGs. © 2014.

Utility of electrocardiogram in the assessment and monitoring of pulmonary hypertension (idiopathic or secondary to pulmonary developmental abnormalities) in patients≤18 years of age.

PubMed

Lau, Kelvin C; Frank, David B; Hanna, Brian D; Patel, Akash R

2014-07-15

Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arterial hypertension (PAH). We examined the electrocardiographic findings that are common in pediatric PAH and assessed for correlation with disease severity and progression. We retrospectively identified patients aged≤18 years followed at a single institution from January 2001 to June 2012 with catheterization-confirmed diagnosis of idiopathic PAH and PAH secondary to pulmonary developmental abnormalities. Patients with an electrocardiography performed within 60 days of catheterization were included. Primary and secondary outcomes are the prevalence of abnormal electrocardiographic findings at the time of catheterization and the association between electrocardiographic and hemodynamic findings and electrocardiographic changes with disease progression on follow-up catheterization, respectively. Of the 100 electrocardiography-catheterization pairs derived from the 46 patients identified, 93% had an electrocardiographic abnormality: 78% had right ventricular hypertrophy (RVH) and 52% had right axis deviation (RAD) for age. In patients with idiopathic PAH, the presence of RVH and RAD correlated with pulmonary vascular resistance and transpulmonary gradient. RAD and RVH on baseline electrocardiogram was associated with an increased risk of disease progression on subsequent catheterization (odds ratio 11.0, 95% confidence interval 1.3 to 96.2, p=0.03) after adjusting for PAH subgroup. The sensitivity, specificity, and positive and negative predictive values of RAD and RVH on baseline electrocardiogram for disease progression were 92%, 48%, 33%, and 95%, respectively. In conclusion, electrocardiographic abnormalities are common in pediatric PAH. RAD and RVH on electrocardiogram were associated with worse hemodynamics, whereas their absence is suggestive of a lack of disease progression. Copyright © 2014 Elsevier Inc. All rights reserved.

21 CFR 870.2350 - Electrocardiograph lead switching adaptor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrocardiograph lead switching adaptor. 870.2350 Section 870.2350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2350...

21 CFR 870.2920 - Telephone electrocardiograph transmitter and receiver.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Telephone electrocardiograph transmitter and receiver. 870.2920 Section 870.2920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices...

21 CFR 870.2350 - Electrocardiograph lead switching adaptor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrocardiograph lead switching adaptor. 870.2350 Section 870.2350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2350...

21 CFR 870.2920 - Telephone electrocardiograph transmitter and receiver.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Telephone electrocardiograph transmitter and receiver. 870.2920 Section 870.2920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices...

Major Electrocardiographic Abnormalities According to the Minnesota Coding System Among Brazilian Adults (from the ELSA-Brasil Cohort Study).

PubMed

Pinto-Filho, Marcelo M; Brant, Luisa C C; Foppa, Murilo; Garcia-Silva, Kaiser B; Mendes de Oliveira, Rackel Aguiar; de Jesus Mendes da Fonseca, Maria; Alvim, Sheila; Lotufo, Paulo A; Mill, José G; Barreto, Sandhi M; Macfarlane, Peter W; Ribeiro, Antonio L P

2017-06-15

The electrocardiogram is a simple and useful clinical tool; nevertheless, few studies have evaluated the prevalence of electrocardiographic abnormalities in the Latin American population. This study aims to evaluate the major electrocardiographic abnormalities according to the Minnesota coding system in Brazilian adults, stratified by gender, age, race, and cardiovascular risk factors. Data from 14,424 adults (45.8% men, age 35 to 74 years) were obtained at baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), according to standardized protocol. The electrocardiogram were obtained with the Burdick Atria 6100 machine, stored on Pyramis System, automatically coded according to the Minnesota coding system by the Glasgow University software and then manually revised. Major abnormalities were more prevalent in men than women (11.3% and 7.9%, p <0.001). These differences were consistent through the different age groups, race, and number of cardiovascular risk factors. Electrocardiographic major abnormalities were more prevalent in black participants for both men (black: 15.1%, mixed: 10.4%, white: 11.1%, p = 0.001) and women (black: 10%, mixed: 7.6%, white: 7.2%, p = 0.004). In conclusion, in this large sample of Brazilian adults, the prevalence of major electrocardiographic abnormalities was higher among men, the elderly, black, and among people with more cardiovascular risk factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Fetal electrocardiograph

NASA Astrophysics Data System (ADS)

Rios, Heriberto; Andrade, Armando; Puente, Ernestina; Lizana, Pablo R.; Mendoza, Diego

2002-11-01

The high intra-uterine death rate is due to failure in appropriately diagnosing some problems in the cardiobreathing system of the fetus during pregnancy. The electrocardiograph is one apparatus which might detect problems at an early stage. With electrodes located near the womb and uterus, in a way similar to the normal technique, the detection of so-called biopotential differences, caused by concentrations of ions, can be achieved. The fetal electrocardiograph is based on an ultrasound technique aimed at detecting intrauterine problems in pregnant women, because it is a noninvasive technique due to the very low level of ultrasound power used. With this system, the following tests can be done: Heart movements from the ninth week onwards; Rapid and safe diagnosis of intrauterine fetal death; Location and size of the placenta. The construction of the fetal electrocardiograph requires instrument level components directly mounted on the printed circuit board, in order to avoid stray capacitance in the cabling which prevents the detection of the E.C.G. activity. The low cost of the system makes it affordable to low budget institutions; in contrast, available commercial systems are priced in U.S. Dollars. (To be presented in Spanish.)

Effects of anti-malarial drugs on the electrocardiographic QT interval modelled in the isolated perfused guinea pig heart system

PubMed Central

2010-01-01

Background Concern over the potential cardiotoxicity of anti-malarial drugs inducing a prolonged electrocardiographic QT interval has resulted in the almost complete withdrawal from the market of one anti-malarial drug - halofantrine. The effects on the QT interval of four anti-malarial drugs were examined, using the guinea pig heart. Methods The guinea pig heart was isolated, mounted on a Langendorff apparatus, and was then perfused with pyruvate-added Klebs-Henseleit solutions containing graded concentrations of the four agents such as quinidine (0.15 - 1.2 μM), quinine (0.3 - 2.4 μM), halofantrine (0.1 - 2.0 μM) and mefloquine (0.1 - 2.0 μM). The heart rate-corrected QaTc intervals were measured to evaluate drug-induced QT prolongation effects. Results Quinidine, quinine, and halofantrine prolonged the QaTc interval in a dose-dependent manner, whereas no such effect was found with mefloquine. The EC50 values for the QaTc prolongation effects, the concentration that gives a half-maximum effect, were quinidine < quinine ≈ halofantrine. Conclusions In this study, an isolated, perfused guinea pig heart system was constructed to assess the cardiotoxic potential of anti-malarial drugs. This isolated perfused guinea pig heart system could be used to test newly developed anti-malarial drugs for their inherent QT lengthening potential. More information is required on the potential variation in unbound drug concentrations in humans, and their role in cardiotoxicity. PMID:21067575

Sex Differences in Timeliness of Reperfusion in Young Patients With ST-Segment-Elevation Myocardial Infarction by Initial Electrocardiographic Characteristics.

PubMed

Gupta, Aakriti; Barrabes, Jose A; Strait, Kelly; Bueno, Hector; Porta-Sánchez, Andreu; Acosta-Vélez, J Gabriel; Lidón, Rosa-Maria; Spatz, Erica; Geda, Mary; Dreyer, Rachel P; Lorenze, Nancy; Lichtman, Judith; D'Onofrio, Gail; Krumholz, Harlan M

2018-03-07

Young women with ST-segment-elevation myocardial infarction experience reperfusion delays more frequently than men. Our aim was to determine the electrocardiographic correlates of delay in reperfusion in young patients with ST-segment-elevation myocardial infarction. We examined sex differences in initial electrocardiographic characteristics among 1359 patients with ST-segment-elevation myocardial infarction in a prospective, observational, cohort study (2008-2012) of 3501 patients with acute myocardial infarction, 18 to 55 years of age, as part of the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study at 103 US and 24 Spanish hospitals enrolling in a 2:1 ratio for women/men. We created a multivariable logistic regression model to assess the relationship between reperfusion delay (door-to-balloon time >90 or >120 minutes for transfer or door-to-needle time >30 minutes) and electrocardiographic characteristics, adjusting for sex, sociodemographic characteristics, and clinical characteristics at presentation. In our study (834 women and 525 men), women were more likely to exceed reperfusion time guidelines than men (42.4% versus 31.5%; P <0.01). In multivariable analyses, female sex persisted as an important factor in exceeding reperfusion guidelines after adjusting for electrocardiographic characteristics (odds ratio, 1.57; 95% CI, 1.15-2.15). Positive voltage criteria for left ventricular hypertrophy and absence of a prehospital ECG were positive predictors of reperfusion delay; and ST elevation in lateral leads was an inverse predictor of reperfusion delay. Sex disparities in timeliness to reperfusion in young patients with ST-segment-elevation myocardial infarction persisted, despite adjusting for initial electrocardiographic characteristics. Left ventricular hypertrophy by voltage criteria and absence of prehospital ECG are strongly positively correlated and ST elevation in lateral leads is negatively correlated with reperfusion delay. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Analysis of Electrocardiographic Data Following Use of Paroxetine in Pediatric Depression and Obsessive-Compulsive Disorder

ERIC Educational Resources Information Center

Krulewicz, Stan; Carpenter, David J.; Fong, Regan; Horrigan, Joseph P.; Lipschitz, Alan; Perera, Philip; Wagner, Karen Dineen

2006-01-01

Objective: This retrospective analysis of electrocardiographic (ECG) data investigated the cardiovascular effects of paroxetine 10-50 mg/day in pediatric patients (7-18 years of age). Data were collected from three 8- to 10-week, randomized, placebo-controlled, double-blind trials of paroxetine in pediatric patients with major depressive disorder…

Electrocardiographic ST-Segment Depression and Exposure to Traffic‐Related Aerosols in Elderly Subjects with Coronary Artery Disease

PubMed Central

Delfino, Ralph J.; Gillen, Daniel L.; Tjoa, Thomas; Staimer, Norbert; Polidori, Andrea; Arhami, Mohammad; Sioutas, Constantinos; Longhurst, John

2011-01-01

Background Air pollutants have not been associated with ambulatory electrocardiographic evidence of ST-segment depression ≥ 1 mm (probable cardiac ischemia). We previously found that markers of primary (combustion-related) organic aerosols and gases were positively associated with circulating biomarkers of inflammation and ambulatory blood pressure in the present cohort panel study of elderly subjects with coronary artery disease. Objectives We specifically aimed to evaluate whether exposure markers of primary organic aerosols and ultrafine particles were more strongly associated with ST-segment depression of ≥ 1 mm than were secondary organic aerosols or PM2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm) mass. Methods We evaluated relations of air pollutants to ambulatory electrocardiographic evidence of cardiac ischemia over 10 days in 38 subjects without ST depression on baseline electrocardiographs. Exposures were measured outdoors in retirement communities in the Los Angeles basin, including daily size-fractionated particle mass and hourly markers of primary and secondary organic aerosols and gases. Generalized estimating equations were used to estimate odds of hourly ST-segment depression (≥ 1 mm) from hourly air pollution exposures and to estimate relative rates of daily counts of ST-segment depression from daily average exposures, controlling for potential confounders. Results We found significant positive associations of hourly ST-segment depression with markers of combustion-related aerosols and gases averaged 1-hr through 3–4 days, but not secondary (photochemically aged) organic aerosols or ozone. The odds ratio per interquartile increase in 2-day average primary organic carbon (5.2 μg/m3) was 15.4 (95% confidence interval, 3.5–68.2). Daily counts of ST-segment depression were consistently associated with primary combustion markers and 2-day average quasi-ultrafine particles < 0.25 μm. Conclusions Results suggest that exposure to quasi-ultrafine particles and combustion-related pollutants (predominantly from traffic) increase the risk of myocardial ischemia, coherent with our previous findings for systemic inflammation and blood pressure. PMID:20965803

Differentiating ST elevation myocardial infarction and nonischemic causes of ST elevation by analyzing the presenting electrocardiogram.

PubMed

Jayroe, Jason B; Spodick, David H; Nikus, Kjell; Madias, John; Fiol, Miguel; De Luna, Antoni Bayés; Goldwasser, Diego; Clemmensen, Peter; Fu, Yuling; Gorgels, Anton P; Sclarovsky, Samuel; Kligfield, Paul D; Wagner, Galen S; Maynard, Charles; Birnbaum, Yochai

2009-02-01

Guidelines recommend that patients with suggestive symptoms of myocardial ischemia and ST-segment elevation (STE) in > or =2 adjacent electrocardiographic leads should receive immediate reperfusion therapy. Novel strategies aimed to reduce door-to-balloon time, such as prehospital wireless electrocardiographic transmission, may be dependent on the interpretation accuracy of the electrocardiogram (ECG) readers. We assessed the ability of experienced electrocardiographers to differentiate among STE, acute STE myocardial infarction (STEMI), and nonischemic STE (NISTE). A total of 116 consecutive ECGs showing STE were studied. Fifteen experienced cardiologists were asked to decide, based on the ECG and assuming that the patient had compatible symptoms, whether they would send each patient for primary percutaneous coronary intervention (PPCI). If NISTE was chosen, the reader selected 1 or more 12 possible options to explain the choice. Of 116 patients, only 8 had STEMI. The percentage of ECGs for which PPCI was recommended for the patient by the individual readers varied widely (7.8% to 33%). There was no significant difference between the North American and Other Countries readers (p = 0.13). The sensitivity and specificity of the individual readers ranged from 50% to 100% (average 75%) and 73% to 97% (average 85%), respectively. There were broad inconsistencies among the readers in the chosen reasons used to classify NISTE. In conclusion, we found wide variations among experienced electrocardiographers in reading ECGs with STE and differentiating STEMI with need for PPCI from NISTE. There is a need to revise our current electrocardiographic criteria for differentiating STEMI from NISTE.

Optimizing Performance Through Sleep-Wake Homeostasis: Integrating Physiological and Neurobehavioral Data via Ambulatory Acquisition in Laboratory and Field Environments

DTIC Science & Technology

2009-04-18

intake and sophisticated signal processing of electroencephalographic (EEG), electrooculographic ( EOG ), electrocardiographic (ECG), and...electroencephalographic (EEG), electrooculographic ( EOG ), electrocardiographic (ECG), and electromyographic (EMG) physiological signals . It also has markedly...ambulatory physiological acquisition and quantitative signal processing; (2) Brain Amp MR Plus 32 and BrainVision Recorder Professional Software Package for

EFFECTS OF INSTILLED EMISSION PARTICULATE MATTER ON ELECTROCARDIOGRAPHIC INDICES AND HEART RATE VARIABILITY (HRV) IN SPONTANEOUSLY HYPERTENSIVE RATS

EPA Science Inventory

EFFECTS OF INSTILLED EMISSION PARTICULATE MATTER (EPM) ON ELECTROCARDIOGRAPHIC INDICES AND HEART RATE VARIABILITY (HRV) IN SPONTANEOUSLY HYPERTENSIVE (SH) RATS. L.B. Wichers1, J.P. Nolan2, W.H. Rowan2, M.J. Campen3, T.P. Jenkins4, D.L. Costa2, and W.P. Watkinson2. 1UNC SPH, Chap...

Relationship between blood calcium level and ST peak interval of electrocardiographic variables in peripartum Holstein cows

PubMed Central

ITOH, Megumi; SAKURAI, Yoshie; NAKAJIMA, Yasuhiro; KAWAMOTO, Satoshi

2015-01-01

The association between blood calcium levels and electrocardiographic variables was compared in 137 normal parturient and 36 peripartum recumbent Holstein cows to determine whether hypocalcemia in peripartum dairy cows can be rapidly diagnosed using electrocardiograph. Inverse of STc (ST peak interval/SS interval0.5) and blood ionized calcium or serum calcium concentrations were strongly correlated, and both correlation coefficients were 0.81 (P<0.001). The 95% prediction interval indicated that cows with STc >0.385 ± 0.001 sec are very likely to be hypocalcemic (blood ionized or serum calcium concentrations of <0.9 mmol/l or <7.5 mg/dl, respectively). These findings indicate that hypocalcemia in parturient cows can be non-invasively estimated using the STc. PMID:26118411

Electrocardiographic Changes in Children and Adolescents Treated with Ziprasidone: A Prospective Study.

ERIC Educational Resources Information Center

McElfresh, Adeline; Scahill, Lawrence; State, Matthew; Martin, Andres

2005-01-01

Objective: To assess the electrocardiographic safety profile of low-dose ziprasidone ([less than or equal to]40 mg/day) among pediatric outpatients treated for up to 6 months. Method: This was a prospective, open-label trial involving 20 subjects with a mean age of 13.2 [+ or -] 3.0 years. Subjects received a mean ziprasidone dose of 30 [+ or -]…

Induced coronary spasm without electrocardiographic signs or symptoms of myocardial ischemia

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

Cipriano, P.R.

1983-03-01

Angiographic studies have shown that coronary artery spasm can be induced with ergonovine maleate. Coronary artery spasm induced by ergonovine maleate in these studies was nearly always accompanied by chest pain and electrocardiographic changes of myocardial ischemia. This report demonstrates that coronary artery spasm induced by ergonovine maleate may be diagnosed by angiography in the absence of these signs or symptoms.

Screening for asymptomatic atrial fibrillation while monitoring the blood pressure at home: trial of regular versus irregular pulse for prevention of stroke (TRIPPS 2.0).

PubMed

Wiesel, Joseph; Abraham, Saji; Messineo, Frank C

2013-06-01

Asymptomatic atrial fibrillation (AF) is a common cause of strokes. Physician screening for AF has been recommended. Home screening for AF may increase the likelihood of detecting asymptomatic AF in patients at risk for stroke because of AF. The aim of this study was to assess the feasibility and accuracy of screening for AF when taking home blood pressure (BP) measurements using an automatic AF-detecting BP monitor. Subjects aged >64 years or those with hypertension, diabetes, congestive heart failure, or previous stroke were enrolled by their primary physicians and given the AF-BP monitor and an electrocardiographic event monitor to use at home for 30 days. The AF-BP monitor reading was compared with the electrocardiographic reading to calculate the sensitivity and specificity of the device for detecting AF. A total of 160 subjects were enrolled, with 10 withdrawing, 1 excluded, and 10 with no AF-BP monitor logs or electrocardiographic recordings. Of the 139 subjects included, 14 had known AF. There was a total of 3,316 days with AF-BP monitor readings and electrocardiographic readings. On the basis of the initial daily AF-BP monitor readings, the AF-BP monitor demonstrated sensitivity of 99.2% and specificity of 92.9% for detecting AF. Two subjects with no histories of AF had AF-BP monitor readings of AF that were confirmed by the electrocardiographic monitor. One of these subjects was started on warfarin. In conclusion, home screening for asymptomatic AF while taking BP measurements can be performed accurately. This can be used to detect new AF, allowing treatment with anticoagulation to reduce the future risk for stroke. Copyright © 2013 Elsevier Inc. All rights reserved.

Alternative diagnostic strategies for coronary artery disease in women: demonstration of the usefulness and efficiency of probability analysis

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

Melin, J.A.; Wijns, W.; Vanbutsele, R.J.

Alternative strategies using conditional probability analysis for the diagnosis of coronary artery disease (CAD) were examined in 93 infarct-free women presenting with chest pain. Another group of 42 consecutive female patients was prospectively analyzed. For this latter group, the physician had access to the pretest and posttest probability of CAD before coronary angiography. These 135 women all underwent stress electrocardiographic, thallium scintigraphic, and coronary angiographic examination. The pretest and posttest probabilities of coronary disease were derived from a computerized Bayesian algorithm. Probability estimates were calculated by the four following hypothetical strategies: SO, in which history, including risk factors, was considered;more » S1, in which history and stress electrocardiographic results were considered; S2, in which history and stress electrocardiographic and stress thallium scintigraphic results were considered; and S3, in which history and stress electrocardiographic results were used, but in which stress scintigraphic results were considered only if the poststress probability of CAD was between 10% and 90%, i.e., if a sufficient level of diagnostic certainty could not be obtained with the electrocardiographic results alone. The strategies were compared with respect to accuracy with the coronary angiogram as the standard. For both groups of women, S2 and S3 were found to be the most accurate in predicting the presence or absence of coronary disease (p less than .05). However, it was found with use of S3 that more than one-third of the thallium scintigrams could have been avoided without loss of accuracy. It was also found that diagnostic catheterization performed to exclude CAD as a diagnosis could have been avoided in half of the patients without loss of accuracy.(ABSTRACT TRUNCATED AT 250 WORDS)« less

Exercise testing after beta-blockade: improved specificity and predictive value in detecting coronary heart disease.

PubMed Central

Marcomichelakis, J; Donaldson, R; Green, J; Joseph, S; Kelly, H B; Taggart, P; Somerville, W

1980-01-01

The value of exercise testing in detecting myocardial ischaemia resulting from coronary atheroma remains controversial. In order to increase the reliability of exercise testing, all its components (asymptomatic, haemodynamic, and electrocardiographic) have been scrutinised. In this study, concerned only with the electrocardiographic response to exercise, the incorporation of beta-blockade into the standard exercise procedure has improved specificity and predictive value without affecting sensitivity. Fifty patients with anginal pain and 50 asymptomatic subjects with an abnormal electrocardiogram were investigated by exercise testing before and after beta-blockade (oxprenolol). All subjects had coronary arteriograms and left ventriculograms, and the results of exercise testing were related to the presence or absence of obstructive coronary artery disease. Possible causes of false positive exercise tests were eliminated by echocardiography. Though beta-blockade was unreliable in distinguishing ischaemic from non-ischaemic resting electrocardiograms, it eliminated all the false positive electrocardiographic responses to exercise in both groups and did not abolish any of the true positive electrocardiographic responses. Thus, specificity and predictive value were improved without reduction in sensitivity. This technique may not necessarily be applicable to other groups of patients or to a random population, but the results of this study suggest it will be a useful additional routine procedure in the investigation of coronary heart disease. PMID:7437172

Use of electrocardiographic-thallium exercise testing in clinical practice

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

Gitler, B.; Fishbach, M.; Steingart, R.M.

Although there is a great deal of data on the accuracy of combined electrocardiographic-thallium exercise testing, little is known about the use of these tests in clinical practice. A quantitative likelihood system was employed to characterize referral patterns for such testing, and the impact of test results on the likelihood of coronary artery disease was examined. Two hundred thirteen subjects consecutively referred for the purpose of establishing or excluding the presence of coronary artery disease were studied. No subject had a history of a prior myocardial infarction. By historical evaluation, 96 had a low likelihood of coronary disease (less thanmore » or equal to 0.20), 88 an intermediate likelihood (0.21 to 0.80) and 29 a high likelihood (greater than 0.80). As anticipated from theoretical analyses, testing produced the greatest shifts in disease likelihood in subjects with an intermediate pretest disease likelihood, and confirmed the historical evaluation in patients at the extremes of pretest disease likelihood. Therefore, although electrocardiographic-thallium stress testing is best suited for subjects with intermediate pretest disease likelihood, the majority of referrals had either a high or low likelihood. Clinicians appear to value confirmatory results in patients at the extremes of pretest disease likelihood. Electrocardiographic exercise testing would serve a similar purpose.« less

Epsilon Waves Detected by Various Electrocardiographic Recording Methods in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy

PubMed Central

Wang, Jing; Yang, Bing; Chen, Hongwu; Ju, Weizhu; Chen, Kai; Zhang, Fengxiang; Cao, Kejiang; Chen, Minglong

2010-01-01

We analyzed the shape and distribution of epsilon waves by 3 various methods of electrocardiographic recording in patients with arrhythmogenic right ventricular cardiomyopathy. Thirty-two patients who met recognized diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy were included in this study (24 men and 8 women; mean age, 42.3 ± 12.9 yr). Epsilon waves were detected by standard 12-lead electrocardiography (S-ECG), right-sided precordial lead electrocardiography (R-ECG), and Fontaine bipolar precordial lead electrocardiography (F-ECG). We found 3 types of epsilon waves: wiggle waves, small spike waves, and smooth potential waves that formed an atypical prolonged R' wave. The most common configuration was small spiked waves. In some circumstances, epsilon waves were evident in some leads (especially in leads V1 through V3), but notches were recorded in the other leads during the corresponding phase. These waves could be detected only by S-ECG in 1 patient, R-ECG in 3 patients, and F-ECG in 5 patients; the rates of epsilon-wave detection by these 3 methods were 38% (12/32), 38% (12/32), and 50% (16/32), respectively. However, the detection rate using combined methods was significantly higher than that by S-ECG alone (SF-ECG 56% vs S-ECG 38%, P = 0.0312; and SRF-ECG 66% vs S-ECG 38%, P = 0.0039). In addition, the rate of widespread T-wave inversion (exceeding V3) was significantly higher in patients with epsilon waves than in those without (48% vs 9%, P = 0.029), as was ventricular tachycardia (95% vs 64%, P = 0.019). These 3 electrocardiographic recording methods should be used in combination to improve the detection rate of epsilon waves. PMID:20844612

FastICA peel-off for ECG interference removal from surface EMG.

PubMed

Chen, Maoqi; Zhang, Xu; Chen, Xiang; Zhu, Mingxing; Li, Guanglin; Zhou, Ping

2016-06-13

Multi-channel recording of surface electromyographyic (EMG) signals is very likely to be contaminated by electrocardiographic (ECG) interference, specifically when the surface electrode is placed on muscles close to the heart. A novel fast independent component analysis (FastICA) based peel-off method is presented to remove ECG interference contaminating multi-channel surface EMG signals. Although demonstrating spatial variability in waveform shape, the ECG interference in different channels shares the same firing instants. Utilizing the firing information estimated from FastICA, ECG interference can be separated from surface EMG by a "peel off" processing. The performance of the method was quantified with synthetic signals by combining a series of experimentally recorded "clean" surface EMG and "pure" ECG interference. It was demonstrated that the new method can remove ECG interference efficiently with little distortion to surface EMG amplitude and frequency. The proposed method was also validated using experimental surface EMG signals contaminated by ECG interference. The proposed FastICA peel-off method can be used as a new and practical solution to eliminating ECG interference from multichannel EMG recordings.

Intracardiac electrocardiography via a "saline-filled central venous catheter electrocardiographic lead": a historical perspective.

PubMed

Madias, John E

2004-04-01

The author describes his experience with a "saline-filled central venous catheter electrocardiographic lead" for the recording of intracardiac electrocardiograms provides a brief description of the methodology, refers to this modality's clinical usefulness, furnishes 2 examples illustrating the contribution of the method to clinical diagnosis, and outlines his literature search to find the discoverer/originator of the employment of a saline-filled intracardiac catheter as an electrocardiogram recording lead.

Pediatric Electrocardiographic Imaging (ECGI) Applications

PubMed Central

Silva, Jennifer N. A.

2014-01-01

Summary Noninvasive electrocardiographic imaging (ECGI) has been used in pediatric and congenital heart patients to better understand their electrophysiologic substrates. In this article we focus on the 4 subjects related to pediatric ECGI: 1) ECGI in patients with congenital heart disease and Wolff-Parkinson-White syndrome, 2) ECGI in patients with hypertrophic cardiomyopathy and pre-excitation, 3) ECGI in pediatric patients with Wolff-Parkinson-White syndrome, and 4) ECGI for pediatric cardiac resynchronization therapy. PMID:25722754

Local Wavelet-Based Filtering of Electromyographic Signals to Eliminate the Electrocardiographic-Induced Artifacts in Patients with Spinal Cord Injury

PubMed Central

Nitzken, Matthew; Bajaj, Nihit; Aslan, Sevda; Gimel’farb, Georgy; Ovechkin, Alexander

2013-01-01

Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG recorded from trunk muscles involved in the activity of breathing can be used as a direct measure of respiratory motor function in patients with spinal cord injury (SCI) or other disorders associated with motor control deficits. However, EMG potentials recorded from these muscles are often contaminated with heart-induced electrocardiographic (ECG) signals. Elimination of these artifacts plays a critical role in the precise measure of the respiratory muscle electrical activity. This study was undertaken to find an optimal approach to eliminate the ECG artifacts from EMG recordings. Conventional global filtering can be used to decrease the ECG-induced artifact. However, this method can alter the EMG signal and changes physiologically relevant information. We hypothesize that, unlike global filtering, localized removal of ECG artifacts will not change the original EMG signals. We develop an approach to remove the ECG artifacts without altering the amplitude and frequency components of the EMG signal by using an externally recorded ECG signal as a mask to locate areas of the ECG spikes within EMG data. These segments containing ECG spikes were decomposed into 128 sub-wavelets by a custom-scaled Morlet Wavelet Transform. The ECG-related sub-wavelets at the ECG spike location were removed and a de-noised EMG signal was reconstructed. Validity of the proposed method was proven using mathematical simulated synthetic signals and EMG obtained from SCI patients. We compare the Root-mean Square Error and the Relative Change in Variance between this method, global, notch and adaptive filters. The results show that the localized wavelet-based filtering has the benefit of not introducing error in the native EMG signal and accurately removing ECG artifacts from EMG signals. PMID:24307920

Local Wavelet-Based Filtering of Electromyographic Signals to Eliminate the Electrocardiographic-Induced Artifacts in Patients with Spinal Cord Injury.

PubMed

Nitzken, Matthew; Bajaj, Nihit; Aslan, Sevda; Gimel'farb, Georgy; El-Baz, Ayman; Ovechkin, Alexander

2013-07-18

Surface Electromyography (EMG) is a standard method used in clinical practice and research to assess motor function in order to help with the diagnosis of neuromuscular pathology in human and animal models. EMG recorded from trunk muscles involved in the activity of breathing can be used as a direct measure of respiratory motor function in patients with spinal cord injury (SCI) or other disorders associated with motor control deficits. However, EMG potentials recorded from these muscles are often contaminated with heart-induced electrocardiographic (ECG) signals. Elimination of these artifacts plays a critical role in the precise measure of the respiratory muscle electrical activity. This study was undertaken to find an optimal approach to eliminate the ECG artifacts from EMG recordings. Conventional global filtering can be used to decrease the ECG-induced artifact. However, this method can alter the EMG signal and changes physiologically relevant information. We hypothesize that, unlike global filtering, localized removal of ECG artifacts will not change the original EMG signals. We develop an approach to remove the ECG artifacts without altering the amplitude and frequency components of the EMG signal by using an externally recorded ECG signal as a mask to locate areas of the ECG spikes within EMG data. These segments containing ECG spikes were decomposed into 128 sub-wavelets by a custom-scaled Morlet Wavelet Transform. The ECG-related sub-wavelets at the ECG spike location were removed and a de-noised EMG signal was reconstructed. Validity of the proposed method was proven using mathematical simulated synthetic signals and EMG obtained from SCI patients. We compare the Root-mean Square Error and the Relative Change in Variance between this method, global, notch and adaptive filters. The results show that the localized wavelet-based filtering has the benefit of not introducing error in the native EMG signal and accurately removing ECG artifacts from EMG signals.

An Innovative Approach to Automatically Detect and Interpret Salient Spatiotemporal Features of a Numeric Field: A Case Study in Electrocardiographic Imaging

NASA Astrophysics Data System (ADS)

Ironi, Liliana; Tentoni, Stefania

2009-08-01

The last decade has witnessed major advancements in the direct application of functional imaging techniques to several clinical contexts. Unfortunately, this is not the case of Electrocardiology. As a matter of fact, epicardial maps, which can hit electrical conduction pathologies that routine surface ECG's analysis may miss, can be obtained non invasively from body surface data through mathematical model-based reconstruction methods. But, their interpretation still requires highly specialized skills that belong to few experts. The automated detection of salient patterns in the map, grounded on the existing interpretation rationale, would therefore represent a major contribution towards the clinical use of such valuable tools, whose diagnostic potential is still largely unexploited. We focus on epicardial activation isochronal maps, which convey information about the heart electric function in terms of the depolarization wavefront kinematics. An approach grounded on the integration of a Spatial Aggregation (SA) method with concepts borrowed from Computational Geometry provides a computational framework to extract, from the given activation data, a few basic features that characterize the wavefront propagation, as well as a more specific set of features that identify an important class of heart rhythm pathologies, namely reentry arrhythmias due to block of conduction.

Electrocardiographic signal-averaging during atrial pacing and effect of cycle length on the terminal QRS in patients with and without inducible ventricular tachycardia.

PubMed

Kremers, M S; Black, W H; Lange, R; Wells, P J; Solo, M

1990-11-01

Electrocardiographic signal-averaging during sinus rhythm (61 to 99 beats/min) and atrial pacing (100 to 171 beats/min) were performed to determine the effect of heart rate on late potentials in 15 patients without (group 1) and 7 patients with (group 2) inducible sustained ventricular tachycardia (VT). In sinus rhythm (79 +/- 12 vs 77 +/- 12 beats/min, difference not significant), the duration of the low-amplitude signal less than 40 microV was longer in group 2 than group 1 (43 +/- 21 vs 26 +/- 8 ms, p = 0.034) and more patients had late potentials (57 vs 7%, p = 0.021), but QRS duration (121 +/- 32 vs 98 +/- 19 ms) and terminal voltage (33 +/- 33 vs 50 +/- 26 ms) were not significantly different. With atrial pacing in group 1 (128 +/- 16 beats/min), 3 patients developed a simultaneous decrease in terminal voltage and an increase in terminal QRS duration consistent with a late potential, but mean total and terminal durations were unchanged. Terminal voltage increased (50 +/- 26 to 59 +/- 40) but not significantly. With atrial pacing in group 2 (119 +/- 12 beats/min) all patients either had a late potential or developed a simultaneous decrease in terminal voltage and an increase in terminal QRS duration (p = 0.001 vs group 1). Root mean square (p = 0.001 vs group 1). Root mean square voltage decreased (33 +/- 23 to 22 +/- 23) and became significantly different from group 1 (p = 0.017). Mean QRS duration, root mean square terminal voltage and low-amplitude terminal QRS duration, however, were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

A left lateral accessory pathway unmasked by rivastigmine.

PubMed

Guenancia, Charles; Fichot, Marie; Garnier, Fabien; Montoy, Mathieu; Laurent, Gabriel

A 75-year-old woman was referred for advice regarding surface electrocardiographic modifications after the initiation of rivastigmine. In our patient, the baseline ECGs appeared perfectly normal. However, the initiation of a cholinesterase inhibitor unmasked a left lateral accessory pathway that had never been diagnosed before. Although cholinesterase inhibitors are known to increase vagal tone, the PR interval was shortened after rivastigmine administration, thus excluding this hypothesis to explain the appearance of the accessory pathway. Therefore, we hypothesized that cholinesterase inhibitors may have increased conduction velocity in the accessory pathway or in the atria. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation of Electrocardiographic Changes with Cardiac Magnetic Resonance Findings in Patients with Hypertrophic Cardiomyopathy

PubMed Central

Paixão, Gabriela Miana de Mattos; Veronesi, Horácio Eduardo; da Silva, Halsted Alarcão Gomes Pereira; de Alencar Neto, José Nunes; Maldi, Carolina de Paulo; Aguiar Filho, Luciano de Figueiredo; Pinto, Ibrahim Masciarelli Francisco; de França, Francisco Faustino de Albuquerque Carneiro; Correia, Edileide de Barros

2018-01-01

Background Electrocardiogram is the initial test in the investigation of heart disease. Electrocardiographic changes in hypertrophic cardiomyopathy have no set pattern, and correlates poorly with echocardiographic findings. Cardiac magnetic resonance imaging has been gaining momentum for better assessment of hypertrophy, as well as the detection of myocardial fibrosis. Objectives To correlate the electrocardiographic changes with the location of hypertrophy in hypertrophic cardiomyopathy by cardiac magnetic resonance. Methods This descriptive cross-sectional study evaluated 68 patients with confirmed diagnosis of hypertrophic cardiomyopathy by cardiac magnetic resonance. The patients’ electrocardiogram was compared with the location of the greatest myocardial hypertrophy by cardiac magnetic resonance. Statistical significance level of 5% and 95% confidence interval were adopted. Results Of 68 patients, 69% had septal hypertrophy, 21% concentric and 10% apical hypertrophies. Concentric hypertrophy showed the greatest myocardial fibrosis mass (p < 0.001) and the greatest R wave size in D1 (p = 0.0280). The amplitudes of R waves in V5 and V6 (p = 0.0391, p = 0.0148) were higher in apical hypertrophy, with statistical significance. Apical hypertrophy was also associated with higher T wave negativity in D1, V5 and V6 (p < 0.001). Strain pattern was found in 100% of the patients with apical hypertrophy (p < 0.001). Conclusion The location of myocardial hypertrophy by cardiac magnetic resonance can be correlated with electrocardiographic changes, especially for apical hypertrophy. PMID:29538524

Parasystole due to re-entry as the possible mechanism of ventricular parasystole with second-degree entrance block.

PubMed

Kinoshita, Shinji; Katoh, Takakazu; Yoshida, Hiroshi

2010-05-01

In 1974, Kinoshita reported a case of 'irregular parasystole' due to type I second-degree entrance block. Since then, many cases of such 'irregular' parasystole have been reported by us. To explain the mechanism of 'irregular' parasystole, two theories have been suggested, namely, 'electrotonic modulation' by Jalife and Moe, and 'type I second-degree entrance block' by us. On the contrary, in 1960, Kinoshita et al. reported a case of concealed bigeminy for the first time. The electrocardiographic findings in concealed bigeminy have suggested that there are dual re-entrant pathways with markedly long effective refractory periods in the re-entrant pathway. We have suggested that parasystole may be caused by re-entry in such re-entrant pathways. In this article, attempts are made to explain the mechanism of all the electrocardiographic findings in our cases of parasystole by 'parasystole due to re-entry'. Using 24 studies on parasystole and 21 studies on concealed extrasystoles that we have reported over 50 years, as well as three exemplary cases in this article, attempts are made to explain all electrocardiographic findings in parasystole by 'parasystole due to re-entry'. The electrocardiographic findings in our previous clinical cases of parasystole and concealed extrasystoles, as well as exemplary cases and diagrams in the present article, strongly suggest 'parasystole due to re-entry' as the mechanism of ventricular parasystole with second-degree entrance block.

[Electrocardiographic differences between apical hypertrophic cardiomyopathy and apical non-ST segment myocardial infarction].

PubMed

Chillik, Iván; Gil Ramírez, Andreina; Ordóñez, Santiago; Tomás, Leandro; Parodi, Josefina; Costabel, Juan Pablo

2018-01-01

Apocal hypertrophic cardiomyopathy (AHCM) is a phenotypic variant within hypertrophic cardiomyopathies, in which ventricular repolarization alterations are present. These electrocardiographic disturbances can mimic an anterior infarction which triggers a series of studies and treatments that may be unnecessary. The aim of this study was to describe and compare electrocardiographic differences in a series of patients with AHCM and apical non-ST segment elevation myocardial infarction in patients (NSTEMI) with T-wave changes. We conducted an observational and retrospective study, including patients with diagnosed AHCM (N = 19) and apical NSTEMI (N = 19) with negative T waves in V1 and V6 lead of the EKG. Those with AHCM presented higher T-wave voltage (7 mV vs. 5 mV, p = 0.001) and peak voltage (29 mV vs. 17 mV, p = 0.003), higher R-waves (25 mV vs. 10 mV, p = 0.0001), and a maximum voltage of R and T sum (R + T) significantly higher (33 vs. 14, p = 0.00001). They also showed a greater T-wave asymmetry, with a TiTp / TpTf ratio > 1. At a cut-off value of 26.5 mV for the R + T variable, 68% sensitivity and 100% specificity were obtained to diagnose AHCM. This study shows the existence of major differences in electrocardiographic presentation of AHCM and apical NSTEMI.

Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy

PubMed Central

Lanjewar, Swapnil S; Chhabra, Lovely; Chaubey, Vinod K; Joshi, Saurabh; Kulkarni, Ganesh; Kothagundla, Chandrasekhar; Kaul, Sudesh; Spodick, David H

2013-01-01

Background The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration. Methods We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups. Results There was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy. Conclusion The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration. PMID:24293995

Diagnostic electrocardiographic dyad criteria of emphysema in left ventricular hypertrophy.

PubMed

Lanjewar, Swapnil S; Chhabra, Lovely; Chaubey, Vinod K; Joshi, Saurabh; Kulkarni, Ganesh; Kothagundla, Chandrasekhar; Kaul, Sudesh; Spodick, David H

2013-01-01

The electrocardiographic diagnostic dyad of emphysema, namely a combination of the frontal vertical P-vector and a narrow QRS duration, can serve as a quasidiagnostic marker for emphysema, with specificity close to 100%. We postulated that the presence of left ventricular hypertrophy in emphysema may affect the sensitivity of this electrocardiographic criterion given that left ventricular hypertrophy generates prominent left ventricular forces and may increase the QRS duration. We reviewed the electrocardiograms and echocardiograms for 73 patients with emphysema. The patients were divided into two groups based on the presence or absence of echocardiographic evidence of left ventricular hypertrophy. The P-vector, QRS duration, and forced expiratory volume in one second (FEV1) were computed and compared between the two subgroups. There was no statistically significant difference in qualitative lung function (FEV1) between the subgroups. There was no statistically significant difference in mean P-vector between the subgroups. The mean QRS duration was significantly longer in patients with left ventricular hypertrophy as compared with those without left ventricular hypertrophy. The presence of left ventricular hypertrophy may not affect the sensitivity of the P-vector verticalization when used as a lone criterion for diagnosing emphysema. However, the presence of left ventricular hypertrophy may significantly reduce the sensitivity of the electrocardiographic diagnostic dyad in emphysema, as it causes a widening of the QRS duration.

In vivo hemodynamic and electrocardiographic changes following Crataegus aronia syn. Azarolus L administration to normotensive Wistar rats.

PubMed

Shatoor, Abdullah S

2013-02-01

To evaluate the effects of the whole plant aqueous extract of Crataegus aronia (C. aronia) syn. Azarolus (L) on the hemodynamic and electrocardiographic intervals in albino rats. This study was carried out in 2 stages at the Research Laboratory, Physiology Department, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia between February and June 2012. First, the effects of C. aronia syn. Azarolus (L) on the hemodynamics and electrocardiograph in 54 Wistar male rats were assessed, then the mechanisms underlying the hemodynamic and electrocardiographic changes observed in the first stage were evaluated in 48 rats of the same species. The C. aronia administered at escalating doses (0.05-20 microgram/kg) produced a dose-time-dependent decrease in heart rate (HR) and mean arterial pressure (MAP). Higher doses (15 and 20 microgram/kg) produced the most significant reduction in both HR and MAP, and induced sinus node suppression and progressive atrio-ventricular blockade. The underlying mechanism of the induced bradyarrhythmia appeared to be due to the direct stimulation of the muscarinic receptor M2 and possible blockade of beta-receptors, while the hypotension was caused by enhanced nitric oxide release. No significant alterations in the electrocardiogram (ECG) components were observed. The administration of the C. aronia syn. Azarolus extract induced bradyarrhythmia and hypotension, without alteration in the ECG components.

Screening of young competitive athletes for the prevention of sudden cardiac death with a wireless electrocardiographic transmission device: a pilot study.

PubMed

Cho, Jae Hyung; Selen, Mats A; Kocheril, Abraham G

2015-08-11

The 12-lead electrocardiographic screening for the prevention of sudden cardiac death in young competitive athletes is not cost-effective and thus not routinely recommended. We investigate whether a less expensive wireless electrocardiographic transmission device can be used to screen for the prevention of sudden cardiac death in this population. During pre-participation screening, twenty college football players underwent two electrocardiograms: a conventional 12-lead electrocardiogram and a wireless 9-lead electrocardiogram. We compared several electrocardiographic parameters (QRS duration, left ventricular hypertrophy using the Cornell voltage criteria and the Sokolow-Lyon criteria, ST deviation and corrected QT interval) to determine the correlation. The QRS duration, left ventricular hypertrophy using the Cornell voltage criteria and the Sokolow-Lyon criteria and corrected QT interval exhibited significant correlation between the two types of electrocardiograms (correlation coefficient 0.878, 0.630, 0.770 and 0.847, respectively with P values of 0.01, 0.003, 0.01 and 0.01, respectively). ST deviation in V1 was weakly correlated between the two types of electrocardiograms without statistical significance (correlation coefficient 0.360 with a P value of 0.119). Our newly developed wireless 9-lead electrocardiogram demonstrated significant correlations with a conventional 12-lead electrocardiogram in terms of QRS duration, left ventricular hypertrophy and corrected QT interval.

Tomato lycopene attenuates myocardial infarction induced by isoproterenol: electrocardiographic, biochemical and anti-apoptotic study.

PubMed

Aman, Upaganlawar; Vaibhav, Patel; Balaraman, R

2012-05-01

To assess the protective effects of lycopene on electrocardiographic, hemodynamic, biochemical and apoptotic changes in isoproterenol induced myocardial infarction. Myocardial infarction was induced in rats by subcutaneous injection of isoproterenol (200 mg/kg) for two consecutive days at an interval of 24 h. Rats were treated with lycopene (10 mg/kg/day, p.o.) for a period of 30 days and isoproterenol (ISO) was injected on the 29th and 30th day. At the end of experiment i.e. on the 31st day electrocardiographic, hemodynamic, biochemical and apoptotic changes were monitored from control and experimental groups. ISO injected rats showed a significant alteration in electrocardiograph pattern and hemodynamic changes (i.e. systolic, diastolic and mean arterial pressure). It also showed significant increase in C-reactive protein, myeloperoxidase, nitrite levels and Caspase-3 protease activity. In addition, it also exhibited alteration in the levels of electrolytes (Na(+), K(+) and Ca(2+)), vitamin E, uric acid and serum protein. Gel electrophoresis of ISO injected rats showed increase in DNA fragmentation. Triphenyl tetrazolium chloride staining of the heart section shows increase area of infarction in ISO injected rats. Pre-co-treatment with lycopene significantly prevented the ISO induced alteration in ECG, haemodynamic, biochemical and apoptotic changes. The present result shows that treatment of lycopene in ISO injected rats significantly attenuates induced myocardial infarction.

Electrocardiographic findings in patients with polycythemia vera.

PubMed

Kayrak, Mehmet; Acar, Kadir; Gul, Enes Elvin; Abdulhalikov, Turyan; Bağlıcaklıoğlu, Murat; Sonmez, Osman; Kaya, Zeynettin; Arı, Hatem

2012-01-01

The 12-lead surface electrocardiogram (ECG) is a useful tool to predict both atrial and ventricular arrhythmias via P-wave and QT measurements and its derivatives. Polycythemia vera (PV) is a chronic myeloproliferative disorder associated with cardiovascular events. The aim of this study was to assess ECG findings of patients with PV. Sixty patients with PV (34 male, mean age 58±11 years) and 60 age and gender-matched healthy volunteers were enrolled into the study. From the 12-lead surface ECG, P-wave and both conventional QT measurements and transmyocardial repolarization parameters (T(peak)-T(end) interval (T(p)-T(e)) and derivatives) were evaluated digitally by two experienced cardiologists. In addition, a novel parameter, Pi was calculated digitally as the standard deviation of the P-wave duration across the 12 ECG leads. QT duration and corrected QT interval were significantly longer in the PV group compared to healthy controls (p<0.01 and p<0.01, respectively). The T(p)-T(e) was longer and the T(p)-T(e)/QT ratio was significantly higher in the PV group compared to the controls. P-wave analyses showed that all P-wave parameters including Pmax, Pmin, P dispersion, and Pi were significantly prolonged in PV patients compared to the controls. The increase of both T(p)-T(e )and P max in the PV group was independent of age, BMI, diabetes and hypertension, gender, systolic blood pressure, hemoglobin, hematocrit, left atrial dimension, left ventricular end-diastolic diameter and early deceleration time in a univariate analysis of co-variance model (F=11.097, p=0.001 and F=31.537, p=0.0001, respectively). The present study demonstrated that PV may be associated with electrocardiographic abnormalities of both atrium and ventricle.

High gain signal averaged electrocardiogram combined with 24 hour monitoring in patients early after myocardial infarction for bedside prediction of arrhythmic events.

PubMed Central

Cripps, T; Bennett, E D; Camm, A J; Ward, D E

1988-01-01

The value of the high gain, signal averaged electrocardiogram combined with 24 hour electrocardiographic monitoring in the prediction of arrhythmic events was assessed in 159 patients in the first week after myocardial infarction. Eleven patients (7%) suffered arrhythmic events during a mean (SD) of 12 (6) months of follow up (range 2-22, median 13 months). The combination of high gain, signal averaged electrocardiography and 24 hour electrocardiographic monitoring was more accurate than either technique alone or than clinical information collected during admission in predicting these events. The combination identified a high risk group of 13 (8%) patients, with an arrhythmic event rate of 62% and a low risk group with an event rate of 2%. The combination of high gain, signal averaged electrocardiography and 24 hour electrocardiographic monitoring in the first week after myocardial infarction provides a rapid, cheap, and non-invasive bedside method for the prediction of arrhythmias. PMID:3179133

[Clinical, electrocardiographic and echocardiographic aspects in elderly hypertensive patients in Senegal].

PubMed

Sarr, Simon Antoine; Babaka, Kana; Mboup, Mouhamadou Cherif; Fall, Pape Diadie; Dia, Khadidiatou; Bodian, Malick; Ndiaye, Mouhamadou Bamba; Kane, Adama; Diao, Maboury; Ba, Serigne Abdou

2016-01-01

Arterial hypertension (HTA) in the elderly is an independent risk factor for cardiovascular disease. Our study aims to describe the clinical, electrocardiographic and echocardiographic aspects of Arterial hypertension in elderly patients. We conducted a descriptive, cross-sectional study from January to September 2013. Hypertensive patients =60 years treated in Outpatient Cardiology Department at the Principal Hospital in Dakar were included in the study. Statistical data were analyzed using Epi Info 7 software and a p-value < 0.05 was taken as significant. A total of 208 patients were enrolled in the study. The average age was 69.9 years with a female predominance (sex ratio 0.85). Average blood pressure was 162/90 mm Hg. HTA was under control in 13% of cases. The ECG showed evidence of rhythm disturbance (17.78%), left atrial enlargement (45.19%), left ventricular hypertrophy (28.85%) and complete atrioventricular block in 2 cases. Holter ECG revealed non-sustained ventricular tachycardia (Lown class IVb) in 4 cases, paroxysmal atrial fibrillation in 6 cases and paroxysmal atrial flutter in 1 case. Echocardiography performed in 140 patients showed mainly concentric left ventricular hypertrophy in 25 patients, occuring more frequently in males (p=0,04) and dilated left atrium in 56,42% of cases, occuring more frequently in elderly patients (p= 0,01). Electrocardiographic and echocardiographic aspects in elderly hypertensive population are characterized by concentric left ventricular hypertrophy and by the frequency of arrhythmias sometimes revealed by long-term continuous external electrocardiographic recording.

Transient left septal and anterior fascicular block associated with type 1 electrocardiographic Brugada pattern.

PubMed

Pérez-Riera, Andrés Ricardo; Barbosa-Barros, Raimundo; Penachini da Costa de Rezende Barbosa, Marianne; Daminello-Raimundo, Rodrigo; de Abreu, Luiz Carlos

The left septal fascicular block (LSFB) or blockage of the middle fibers of the left bundle branch is probably caused mainly by - in the developed world - the proximal obstruction of the left anterior descending artery (LAD) before its first anterior septal perforator branch (S 1 ). The association of transient LSFB and left anterior fascicular block (LAFB) - left bifascicular block - and the electrocardiographic type 1 Brugada pattern (BrP) has not been described in the literature yet. Copyright © 2017 Elsevier Inc. All rights reserved.

Real-Time, High-Frequency QRS Electrocardiograph

NASA Technical Reports Server (NTRS)

Schlegel, Todd T.; DePalma, Jude L.; Moradi, Saeed

2003-01-01

An electronic system that performs real-time analysis of the low-amplitude, high-frequency, ordinarily invisible components of the QRS portion of an electrocardiographic signal in real time has been developed. Whereas the signals readily visible on a conventional electrocardiogram (ECG) have amplitudes of the order of a millivolt and are characterized by frequencies <100 Hz, the ordinarily invisible components have amplitudes in the microvolt range and are characterized by frequencies from about 150 to about 250 Hz. Deviations of these high-frequency components from a normal pattern can be indicative of myocardial ischemia or myocardial infarction

Sparse Matrix for ECG Identification with Two-Lead Features.

PubMed

Tseng, Kuo-Kun; Luo, Jiao; Hegarty, Robert; Wang, Wenmin; Haiting, Dong

2015-01-01

Electrocardiograph (ECG) human identification has the potential to improve biometric security. However, improvements in ECG identification and feature extraction are required. Previous work has focused on single lead ECG signals. Our work proposes a new algorithm for human identification by mapping two-lead ECG signals onto a two-dimensional matrix then employing a sparse matrix method to process the matrix. And that is the first application of sparse matrix techniques for ECG identification. Moreover, the results of our experiments demonstrate the benefits of our approach over existing methods.

LEOPARD syndrome: what are café noir spots?

PubMed

Rodríguez-Bujaldón, Alfonso; Vazquez-Bayo, Carmen; Jimenez-Puya, Rafael; Galan-Gutierrez, Manuel; Moreno-Gimenez, José; Rodriguez-Garcia, Alfonso; Tercedor, Jesus; Velez-Garcia, Antonio

2008-01-01

Lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retarded growth, and deafness syndrome (multiple lentigines syndrome) is most often characterized by multiple lentigines and cardiac conduction defects. Café noir spot is a term proposed, by analogy to café au lait spots, for the larger and darkly pigmented patches that are frequently observed in patients with this syndrome. Although presumed by some authors to represent lentigines, the histologic features of café noir spots have not been well documented in the literature. Only two previous cases have been reported in which a biopsy of the café noir spots than melanocytic nevi. We describe the histologic characteristics of seven café noir spots in six patients with lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retarded growth, and deafness syndrome. Three lesions represented melanocytic nevi (one with dysplastic features), and four were compatible with lentigo simplex. These findings help our understanding of the histologic spectrum of pigmented lesions in lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormalities of genitalia, retarded growth, and deafness syndrome.

Regional Pericarditis Status Post Cardiac Ablation: A Case Report

PubMed Central

Orme, Joseph; Eddin, Moneer; Loli, Akil

2014-01-01

Context: Regional pericarditis is elusive and difficult to diagnosis. Healthcare providers should be familiar with post-cardiac ablation complications as this procedure is now widespread and frequently performed. The management of regional pericarditis differs greatly from that of acute myocardial infarction. Case report: A 52 year-old male underwent atrial fibrillation ablation and developed severe mid-sternal chest pain the following day with electrocardiographic findings suggestive of acute myocardial infarction, and underwent coronary angiography, a left ventriculogram, and 2D transthoracic echocardiogram, all of which were unremarkable without evidence of obstructive coronary disease, wall motion abnormalities, or pericardial effusions. Ultimately, the patient was diagnosed with regional pericarditis. After diagnosis, the patient's presenting symptoms resolved with treatment including nonsteroidal anti-inflammatory agents and colchicine. Conclusion: This is the first reported case study of regional pericarditis status post cardiac ablation. Electrocardiographic findings were classic for an acute myocardial infarction; however, coronary angiography and left ventriculogram demonstrated no acute coronary occlusion or ventricular wall motion abnormalities. Healthcare professionals must remember that the electrocardiographic findings in pericarditis are not always classic and that pericarditis can occur status post cardiac ablation. PMID:25317395

Regional pericarditis status post cardiac ablation: a case report.

PubMed

Orme, Joseph; Eddin, Moneer; Loli, Akil

2014-09-01

Regional pericarditis is elusive and difficult to diagnosis. Healthcare providers should be familiar with post-cardiac ablation complications as this procedure is now widespread and frequently performed. The management of regional pericarditis differs greatly from that of acute myocardial infarction. A 52 year-old male underwent atrial fibrillation ablation and developed severe mid-sternal chest pain the following day with electrocardiographic findings suggestive of acute myocardial infarction, and underwent coronary angiography, a left ventriculogram, and 2D transthoracic echocardiogram, all of which were unremarkable without evidence of obstructive coronary disease, wall motion abnormalities, or pericardial effusions. Ultimately, the patient was diagnosed with regional pericarditis. After diagnosis, the patient's presenting symptoms resolved with treatment including nonsteroidal anti-inflammatory agents and colchicine. This is the first reported case study of regional pericarditis status post cardiac ablation. Electrocardiographic findings were classic for an acute myocardial infarction; however, coronary angiography and left ventriculogram demonstrated no acute coronary occlusion or ventricular wall motion abnormalities. Healthcare professionals must remember that the electrocardiographic findings in pericarditis are not always classic and that pericarditis can occur status post cardiac ablation.

[Carbamazepine cardiotoxicity in acute poisoning].

PubMed

Todorović, V; Randelović, S; Joksović, D; Jović-Stosić, J; Vucinić, S; Glisović, L

1993-01-01

Manifestations of cardiotoxicity in 9 patients with acute carabamazepine poisoning treated at the Clinic of Toxicology and Clinical Pharmacology of the M.M.A. in 1989 are reported. In all patients together with symptoms and signs characteristic for acute carbamezapine poisoning, there have been also present disorders of the cardiovascular system. The most common clinical signs of cardiotoxicity have been tachycardia and hypotension, and electrocardiographic, ventricular extrasystoles and repolarization disorders. Cardiotoxic manifestations in two cases have been the vital threat for the patients. After application of nonspecific and symptomatic therapy, clinical and electrocardiographic signs of cardiotoxicity were withdrawn, that is, heart sequeles were not recorded.

Torso geometry reconstruction and body surface electrode localization using three-dimensional photography.

PubMed

Perez-Alday, Erick A; Thomas, Jason A; Kabir, Muammar; Sedaghat, Golriz; Rogovoy, Nichole; van Dam, Eelco; van Dam, Peter; Woodward, William; Fuss, Cristina; Ferencik, Maros; Tereshchenko, Larisa G

We conducted a prospective clinical study (n=14; 29% female) to assess the accuracy of a three-dimensional (3D) photography-based method of torso geometry reconstruction and body surface electrodes localization. The position of 74 body surface electrocardiographic (ECG) electrodes (diameter 5mm) was defined by two methods: 3D photography, and CT (marker diameter 2mm) or MRI (marker size 10×20mm) imaging. Bland-Altman analysis showed good agreement in X (bias -2.5 [95% limits of agreement (LoA) -19.5 to 14.3] mm), Y (bias -0.1 [95% LoA -14.1 to 13.9] mm), and Z coordinates (bias -0.8 [95% LoA -15.6 to 14.2] mm), as defined by the CT/MRI imaging, and 3D photography. The average Hausdorff distance between the two torso geometry reconstructions was 11.17±3.05mm. Thus, accurate torso geometry reconstruction using 3D photography is feasible. Body surface ECG electrodes coordinates as defined by the CT/MRI imaging, and 3D photography, are in good agreement. Copyright © 2017 Elsevier Inc. All rights reserved.

Segmentation of ECG from Surface EMG Using DWT and EMD: A Comparison Study

NASA Astrophysics Data System (ADS)

Shahbakhti, Mohammad; Heydari, Elnaz; Luu, Gia Thien

2014-10-01

The electrocardiographic (ECG) signal is a major artifact during recording the surface electromyography (SEMG). Removal of this artifact is one of the important tasks before SEMG analysis for biomedical goals. In this paper, the application of discrete wavelet transform (DWT) and empirical mode decomposition (EMD) for elimination of ECG artifact from SEMG is investigated. The focus of this research is to reach the optimized number of decomposed levels using mean power frequency (MPF) by both techniques. In order to implement the proposed methods, ten simulated and three real ECG contaminated SEMG signals have been tested. Signal-to-noise ratio (SNR) and mean square error (MSE) between the filtered and the pure signals are applied as the performance indexes of this research. The obtained results suggest both techniques could remove ECG artifact from SEMG signals fair enough, however, DWT performs much better and faster in real data.

Inverse Electrocardiographic Source Localization of Ischemia: An Optimization Framework and Finite Element Solution

PubMed Central

Wang, Dafang; Kirby, Robert M.; MacLeod, Rob S.; Johnson, Chris R.

2013-01-01

With the goal of non-invasively localizing cardiac ischemic disease using body-surface potential recordings, we attempted to reconstruct the transmembrane potential (TMP) throughout the myocardium with the bidomain heart model. The task is an inverse source problem governed by partial differential equations (PDE). Our main contribution is solving the inverse problem within a PDE-constrained optimization framework that enables various physically-based constraints in both equality and inequality forms. We formulated the optimality conditions rigorously in the continuum before deriving finite element discretization, thereby making the optimization independent of discretization choice. Such a formulation was derived for the L2-norm Tikhonov regularization and the total variation minimization. The subsequent numerical optimization was fulfilled by a primal-dual interior-point method tailored to our problem’s specific structure. Our simulations used realistic, fiber-included heart models consisting of up to 18,000 nodes, much finer than any inverse models previously reported. With synthetic ischemia data we localized ischemic regions with roughly a 10% false-negative rate or a 20% false-positive rate under conditions up to 5% input noise. With ischemia data measured from animal experiments, we reconstructed TMPs with roughly 0.9 correlation with the ground truth. While precisely estimating the TMP in general cases remains an open problem, our study shows the feasibility of reconstructing TMP during the ST interval as a means of ischemia localization. PMID:23913980

Prevalence of Electrocardiographic Patterns Associated With Sudden Cardiac Death in the Spanish Population Aged 40 Years or Older. Results of the OFRECE Study.

PubMed

Awamleh García, Paula; Alonso Martín, Joaquín Jesús; Graupner Abad, Catherine; Jiménez Hernández, Rosa María; Curcio Ruigómez, Alejandro; Talavera Calle, Pedro; Cristóbal Varela, Carmen; Serrano Antolín, José; Muñiz, Javier; Gómez Doblas, Juan José; Roig, Eulalia

2017-10-01

Some electrocardiographic patterns are associated with an increased risk of sudden cardiac death due to ventricular arrhythmias. There is no information on the prevalence of these patterns in the general population in Spain. The objective of this study was to analyze the prevalence of these patterns and associated clinical and epidemiological factors. This subanalysis of the OFRECE study selected a representative sample of the Spanish population aged ≥ 40 years. We studied the presence or absence of electrocardiographic patterns of Brugada syndrome and QT interval abnormalities. Clinical data and electrocardiograms were available in all participants. Electrocardiograms were evaluated by 2 cardiologists and a third cardiologist was consulted if there was disagreement in the diagnosis. We calculated the weighted prevalence and clinical factors associated with the presence of Brugada-type patterns or QT segment abnormalities. Overall, 8343 individuals were evaluated (59.2 years, 52.4% female). There were 12 Brugada cases (type 1, 2 cases; type 2, 10 cases; weighted prevalence, 0.13%). For corrected QT (QTc) analysis, we excluded participants with left bundle branch block or without sinus rhythm. Weighted prevalences were as follows: short QTc (< 340ms) 0.18%, borderline QTc (441-469ms) 8.33%, long QTc (≥ 470ms criterion) 1.01% and long QTc (≥ 480 criterion) 0.42%. A total of 0.6% to 1.1% of the Spanish population aged ≥ 40 years has an electrocardiographic pattern associated with a higher risk of sudden death (Brugada syndrome, long QT, or short QT). Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

J Wave Syndromes: History and Current Controversies

PubMed Central

Liu, Tong; Zheng, Jifeng

2016-01-01

The concept of J wave syndromes was first proposed in 2004 by Yan et al for a spectrum of electrocardiographic (ECG) manifestations of prominent J waves that are associated with a potential to predispose affected individuals to ventricular fibrillation (VF). Although the concept of J wave syndromes is widely used and accepted, there has been tremendous debate over the definition of J wave, its ionic and cellular basis and arrhythmogenic mechanism. In this review article, we attempted to discuss the history from which the concept of J wave syndromes (JWS) is evolved and current controversies in JWS. PMID:27721848

Electrocardiographic signals and swarm-based support vector machine for hypoglycemia detection.

PubMed

Nuryani, Nuryani; Ling, Steve S H; Nguyen, H T

2012-04-01

Cardiac arrhythmia relating to hypoglycemia is suggested as a cause of death in diabetic patients. This article introduces electrocardiographic (ECG) parameters for artificially induced hypoglycemia detection. In addition, a hybrid technique of swarm-based support vector machine (SVM) is introduced for hypoglycemia detection using the ECG parameters as inputs. In this technique, a particle swarm optimization (PSO) is proposed to optimize the SVM to detect hypoglycemia. In an experiment using medical data of patients with Type 1 diabetes, the introduced ECG parameters show significant contributions to the performance of the hypoglycemia detection and the proposed detection technique performs well in terms of sensitivity and specificity.

The normal electrocardiogram of four species of conscious raptors.

PubMed

Talavera, J; Guzmán, M J; del Palacio, M J Fernández; Albert, A P; Bayón, A

2008-02-01

The aim of this study was to describe normal ECG patterns and values in four species of conscious raptors (Eurasian kestrel, Griffon vulture, Little owl, and Eurasian Eagle owl). Electrocardiograms were carried out in 75 conscious birds belonging to four species of raptors. Lead II waveforms were analysed to determine amplitudes and durations of waves and intervals. Morphologic patterns of P-QRS-T deflections were analysed in the six limb leads. Rhythm, heart rate, mean electrical axis, presence of Ta wave, ST slurring, and P-on-T phenomenon were also studied. The influence of species, body weight and heart rate in electrocardiographic variables were statistically analysed (P < 0.05). Sinus rhythm was present in all tracings, showing sinus arrhythmia in four cases. Ta wave was present in six tracings and P-on-T phenomenon in four. ST segment could be identified in all tracings, being mainly high above baseline. Significant differences between species were found for all the electrocardiographic parameters. The heart rate and body weight were also found to be a significant influence in most parameters. This study provides electrocardiographic data for four species of raptors that can be used to establish comparisons for clinical purposes.

Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method.

PubMed

Lázzari, J O; Pereira, M; Antunes, C M; Guimarães, A; Moncayo, A; Chávez Domínguez, R; Hernández Pieretti, O; Macedo, V; Rassi, A; Maguire, J; Romero, A

1998-11-01

An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (kappa) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (kappa = 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

Therapeutic implications of transesophageal echocardiography after transthoracic echocardiography on acute stroke patients

PubMed Central

de Abreu, Tiago Tribolet; Mateus, Sonia; Carreteiro, Cecilia; Correia, Jose

2008-01-01

Background The role of transesophageal echocardiography (TEE) in the evaluation of acute stroke patients is still ill-defined. We conducted a prospective observational study to find the prevalence of TEE findings that indicate anticoagulation as beneficial, in acute ischemic stroke patients without indication for anticoagulation based on clinical, electrocardiographic and transthoracic echocardiography (TTE) findings. Methods We prospectively studied all patients referred to our laboratory for TTE and TEE. Patients were excluded if the diagnosis was not acute ischemic stroke or if they had an indication for anticoagulation based on clinical, electrocardiographic, or TTE data. Patients with TEE findings that might indicate anticoagulation as beneficial were identified. Results A total of 84 patients with acute ischemic stroke and without indication for anticoagulation based on clinical and electrocardiographic or TTE data were included in the study. Findings indicating anticoagulation as beneficial were found in 32.1%: spontaneous echo contrast (1.2%), complex aortic atheroma (27.4%), thrombus (8.3%), and simultaneous patent foramen ovale and atrial septal aneurysm (2.4%). Conclusions The results of our study show that TEE can have therapy implications in 32.1% of ischemic stroke patients in sinus rhythm and with TTE with no indication for anticoagulation. PMID:18629351

Electrocardiographic effects of hawthorn (Crataegus oxyacantha) in healthy volunteers: A randomized controlled trial.

PubMed

Trexler, Stephanie E; Nguyen, Elaine; Gromek, Samantha M; Balunas, Marcy J; Baker, William L

2018-04-19

The objective of this study was to evaluate the electrocardiographic effects of hawthorn in healthy adult volunteers. It was double-blind cross-over trial randomized 20 healthy adult volunteers to receive either a single oral 160-mg dose of hawthorn or matching placebo. Triplicate 12-lead electrocardiograms were taken before treatment and at 1-, 2-, 4-, and 6-hr post-dose. Following at least a 7-day washout period, participants were crossed over to the opposing treatment arm and had the measurements repeated. The primary endpoint was the change in corrected (Fridericia) QT intervals (QT c I) at 4 and 6 hr. Maximum post-dose QT c I and changes in PR and QRS intervals were measured. No significant differences in 4- or 6-hr QT c I were seen between hawthorn and placebo. Maximum post-dose QT c I in the hawthorn and placebo groups were similar (346 ± 35 vs 346 ± 40 ms; p = .979). No significant adverse events were seen. In conclusion, a single dose of oral hawthorn had no effect on electrocardiographic parameters in healthy volunteers. Copyright © 2018 John Wiley & Sons, Ltd.

Electrocardiographic left ventricular strain pattern: everything old is new again.

PubMed

Schocken, Douglas D

2014-01-01

Electrocardiographic left ventricular hypertrophy (LVH) has many faces with countless features. Beyond the classic measures of LVH, including QRS voltage and duration, the left ventricular (LV) strain pattern is an element whereby characteristic R-ST depression is followed by a concave ST segment that ends in an asymmetrically inverted T wave. The LV strain pattern generally appears in states of increased systemic blood pressure and must be differentiated from similar but not identical ST-T waves indicating ischemia. The LV strain pattern has been found in population studies to be associated with poor prognosis and increased risk of adverse cardiovascular outcomes. Regression of LV strain pattern parallels decline in systemic BP during clinical trials of anti-hypertensive therapies but does not indicate or serve as a surrogate for decrease in LV mass. Newer techniques in data collection and processing may allow the process of strain to be studied in more detail to determine the ways in which electrical remodeling of the left ventricle as characterized by LVH with 'repolarization abnormalities' indicates how CV risk might be managed by using LV strain pattern as an electrocardiographic biomarker. Copyright © 2014 Elsevier Inc. All rights reserved.

Hypertensive crisis-induced electrocardiographic changes: a case series

PubMed Central

2009-01-01

Introduction Myocardial injury is one of the most notorious complications of a hypertensive crisis. Key electrocardiograph signs used to detect cardiac injury such as ST segment changes and cardiac arrhythmias usually indicate acute ongoing end-organ damage. Lack of early signs to predict end-organ damage might lead to a delay in the initiation of therapy and selection of the incorrect therapeutic strategy. Case presentation We describe five cases of tall, hyper acute symmetrical T-waves alone or accompanied by other electrocardiograph abnormalities in five healthy participants: three women aged 52, 60 and 62-years and two men aged 49 and 66-years, during a tyramine-monoamine oxidase-inhibitor interaction, phase I clinical trial. T-wave changes appeared early during the course of the hypertensive crisis and were attributed to subendocardial ischemia. The changes were transient and reverted to baseline in parallel with a fall in blood pressure. Conclusion Recognition of tall symmetrical T-waves in early phases of hypertensive crisis heralds commencement of myocardial damage. This calls for prompt medical intervention to avoid an impending irreversible myocardial injury. It is our belief that these findings will add new insight into the management of hypertensive crisis and will open avenues of further investigation. PMID:19918270

Hypertensive crisis-induced electrocardiographic changes: a case series.

PubMed

Farha, Khalid Abou; van Vliet, André; van Marle, Sjoerd; Vrijlandt, Patrick; Westenbrink, Daan

2009-08-20

Myocardial injury is one of the most notorious complications of a hypertensive crisis. Key electrocardiograph signs used to detect cardiac injury such as ST segment changes and cardiac arrhythmias usually indicate acute ongoing end-organ damage. Lack of early signs to predict end-organ damage might lead to a delay in the initiation of therapy and selection of the incorrect therapeutic strategy. We describe five cases of tall, hyper acute symmetrical T-waves alone or accompanied by other electrocardiograph abnormalities in five healthy participants: three women aged 52, 60 and 62-years and two men aged 49 and 66-years, during a tyramine-monoamine oxidase-inhibitor interaction, phase I clinical trial. T-wave changes appeared early during the course of the hypertensive crisis and were attributed to subendocardial ischemia. The changes were transient and reverted to baseline in parallel with a fall in blood pressure. Recognition of tall symmetrical T-waves in early phases of hypertensive crisis heralds commencement of myocardial damage. This calls for prompt medical intervention to avoid an impending irreversible myocardial injury. It is our belief that these findings will add new insight into the management of hypertensive crisis and will open avenues of further investigation.

Clinical and Electrocardiographic Characteristics of Electrical Storms Due to Monomorphic Ventricular Tachycardia Refractory to Intravenous Amiodarone.

PubMed

Murata, Hiroshige; Miyauchi, Yasushi; Hayashi, Meiso; Iwasaki, Yu-Ki; Yodogawa, Kenji; Ueno, Akira; Hayashi, Hiroshi; Tsuboi, Ippei; Uetake, Shunsuke; Takahashi, Kenta; Yamamoto, Teppei; Maruyama, Mitsunori; Akutsu, Koichi; Yamamoto, Takeshi; Kobayashi, Yoshinori; Tanaka, Keiji; Atarashi, Hirotsugu; Katoh, Takao; Shimizu, Wataru

2015-01-01

Few reports are available on the characteristics of electrical storms of ventricular tachycardia (VT storm) refractory to intravenous (IV) amiodarone. IV-amiodarone was administered to 60 patients with ventricular tachyarrhythmia between 2007 and 2012. VT storms, defined as 3 or more episodes of VT within 24 h, occurred in 30 patients (68±12 years, 7 female), with 12 having ischemic and 18 non-ischemic heart disease. We compared the clinical and electrocardiographic characteristics of the patients with VT storms suppressed by IV-amiodarone (Effective group) to those of patients not affected by the treatment (Refractory group). IV-amiodarone could not control recurrence of VT in 9 patients (30%). The Refractory group comprised 5 patients with acute myocardial infarctions. Although there was no difference in the VT cycle length, the QRS duration of both the VT and premature ventricular contractions (PVCs) followed by VT was narrower in the Refractory group than in the Effective group (140±30 vs. 178±25 ms, P<0.01; 121±14 vs. 179±22 ms, P<0.01). In the Refractory group, additional administration of IV-mexiletine and/or Purkinje potential-guided catheter ablation was effective. IV-amiodarone-refractory VT exhibited a relatively narrow QRS tachycardia. The narrow triggering PVCs, suggesting a Purkinje fiber origin, may be treated by additional IV-mexiletine and endocardial catheter ablation.

Electromuscular incapacitating devices discharge and risk of severe bradycardia.

PubMed

Havranek, Stepan; Neuzil, Petr; Linhart, Ales

2015-06-01

Electromuscular incapacitating devices (EMDs) are high-voltage, low-current stimulators causing involuntary muscle contractions and sensory response. Existing evidence about cardiac effects of EMD remains inconclusive. The aim of our study was to analyze electrocardiographic, echocardiographic, and microvolt T-wave alternans (MTWA) changes induced by EMD discharge.We examined 26 volunteers (22 men; median age 30 years) who underwent single standard 5-second duration exposure to TASER X26 under continuous echocardiographic and electrocardiographic monitoring. Microvolt T-wave alternans testing was performed at baseline (MTWA-1), as well as immediately and 60 minutes after EMD exposure (MTWA-2 and MTWA-3, respectively).Mean heart rate (HR) increased significantly from 88 ± 17 beats per minute before to 129 ± 17 beats per minute after exposure (P < 0.001). However, in 2 individuals, an abrupt decrease in HR was observed. In one of them, interval between two consecutive beats increased up to 1.7 seconds during the discharge. New onset of supraventricular premature beats was observed after discharge in 1 patient. Results of MTWA-1, MTWA-2, and MTWA-3 tests were positive in one of the subjects, each time in a different case.Standard EMD exposure can be associated with a nonuniform reaction of HR and followed by heart rhythm disturbances. New MTWA positivity can reflect either the effect of EMD exposure or a potential false positivity of MTWA assessments.

Study of the Properties of Plessey's Electrocardiographic Capacitive Electrodes for Portable Systems

NASA Astrophysics Data System (ADS)

Uvarov, A. A.; Lezhnina, I. A.; Overchuk, K. V.; Starchak, A. S.; Akhmedov, Sh D.; Larioshina, I. A.

2016-01-01

Cardiac diseases are still most widely spread in all regions of the world. And more and more devices are invented to satisfy increasing requirements of the patients. One of the perspective technologies in cardiac diagnostics is capacitive sensing ECG electrodes. This article describes a study of the properties of electrocardiographic capacitive electrodes PS25255 from Plessey Semiconductors for portable systems as well as some undocumented parameters of these sensors. We developed special cardiograph using Plessey's electrodes and applied to the number of patients with ischemic heart disease. We paid our attention mostly to the correct transition of the ST segment as it has critical impact on the diagnostics of ischemic heart disease.

[Correlation of the quantitative ECG and echocardiogram indices in left ventricular hypertrophy according to correlational analysis data].

PubMed

Alekperov, I I; Dorofeeva, Z Z; Iurenev, A P

1981-11-01

In 47 patients with arterial hypertension and clinicoroentgenological signs of hypertrophy of the left ventricle the echo- and electrocardiographic study (the McFee-Parungao system) was carried out. Highly significant (p less than 0.001) direct correlation was revealed between the index of the corrected ECG, such as sigma R x,y,z + + sigma S x,y,z and Rx + Sz with echocardiographic indices of mass r = +0.851 and +0.848, respectively, and the thickness of the left ventricle of the myocardium (r = +0.806 and +0.794, respectively). The above electrocardiographic indices do not correlate to the main echocardiographic indices of the contractile function of the left ventricle.

Design and implementation of an electrocardiographical signal acquisition and digital processing system orientated to the detection of paroxysmal arrhythmias

NASA Astrophysics Data System (ADS)

Iriart Braceli, Agustín; Exequiel Morani, Jorge

2011-12-01

This article describes the design, technical aspects and implementation of a device capable of acquiring electrocardiograph signals; visualize them in real time over a graphic liquid crystal display (GLCD), and the storage of these ECG registers on a SD memory card. It also details a noise suppression algorithm using the Wavelet Transform. This system was specially developed to cover some bankruptcy that presents actual Holters or ECG regarding the detection of paroxysmal arrhythmias. The contribution of this work is settled on its portability and low production cost. The filtering method used provides an ECG signal without any significant noise and appropriate to the diagnosis of cardiac pathologies.

STUDIES WITH THE ELECTROCARDIOGRAPH ON THE ACTION OF THE VAGUS NERVE ON THE HUMAN HEART

PubMed Central

Robinson, G. Canby; Draper, George

1911-01-01

In hearts showing auricular fibrillation mechanical stimulation of the right vagus nerve causes, as a rule, marked slowing or stoppage of ventricular rhythm, without producing any appreciable effect in the electrocardiographic record of the auricular fibrillation. The ventricular pauses are apparently due to the blocking of stimuli from the auricles. The force of ventricular systole is distinctly weakened for several beats after vagus stimulation, and ectopic ventricular systoles have been seen in several instances, apparently the result of the vagus action. There may, in some cases, be lowered excitability of the ventricles, while no constant change is seen in the size of the electrical complexes representing ventricular systole. PMID:19867466

[Effect of pazufloxacin mesilate, a new quinolone antibacterial agent, for intravenous use on QT interval].

PubMed

Fukuda, Hitoshi; Morita, Yukie; Shiotani, Norio; Mizuo, Midori; Komae, Norihisa

2004-08-01

The potential for QT interval prolongation of pazufloxacin mesilate (PZFX mesilate), a new quinolone antibacterial agent for intravenous use, was investigated by in vitro and in vivo electrophysiology studies. Following results were obtained. In vitro electrophysiology study using guinea pig papillary muscles: PZFX mesilate (30-300 microM) had no effects on resting membrane potential (RMP), action potential amplitude (APA) and action potential duration (APD). Reference quinolones, sparfloxacin (3-30 microM) and moxifloxacin (10-100 microM), had no effects on RMP and APA, but significantly prolonged APD at more than 3 and 10 microM, respectively, while ciprofloxacin (10-100 microM) had no effect on each parameter. In vivo electrophysiology study using anesthetized dogs: PZFX mesilate had no effects on electrocardiograph parameter (PR interval, QRS interval, QT interval and QTc) after intravenous administration of 3-30 mg/kg. These results suggest that PZFX mesilate has low potential for QT interval prolongation.

Echocardiographic evaluation during weaning from mechanical ventilation.

PubMed

Schifelbain, Luciele Medianeira; Vieira, Silvia Regina Rios; Brauner, Janete Salles; Pacheco, Deise Mota; Naujorks, Alexandre Antonio

2011-01-01

Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation. To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T-tube; and comparing patient subgroups: success vs. failure in weaning. Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T-tube. Pressure support ventilation vs. T-tube and weaning success vs. failure were compared using ANOVA and Student's t-test. The level of significance was p<0.05. Twenty-four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T-tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation. No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T-tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients.

A Carbamazepine-induced Brugada-type Electrocardiographic Pattern in a Patient with Schizophrenia

PubMed Central

Ota, Hisanobu; Kawamura, Yuichiro; Sato, Nobuyuki; Hasebe, Naoyuki

2017-01-01

We report the case of a 61-year-old man with schizophrenia who was treated with carbamazepine, in whom electrocardiography showed transient Brugada-type ST elevation. He had been hospitalized our hospital's Department of Psychiatry and had been diagnosed with pneumonia. On the following day, electrocardiography showed coved-type ST elevation in the right precordial leads and a blood examination revealed that the patient's carbamazepine concentration was at the upper limit of the standard range, as well as hypothyroidism. The patient's electrocardiogram normalized after the withdrawal of carbamazepine. We demonstrated that the patient's carbamazepine concentration-and not hypothyroidism-was associated with the serial electrocardiographic changes by monitoring the patient's blood concentration of carbamazepine and his thyroid function. PMID:29142189

The pattern of activation of the sympathetic nervous system during tilt-induced syncope.

PubMed

Zyśko, Dorota; Gajek, Jacek; Sciborski, Ryszard; Smereka, Jacek; Checiński, Igor; Mazurek, Walentyna

2007-04-01

A 49-year-old patient with a history of situational syncope and minimal electrocardiographic signs of accessory pathway is described. The evidence for pre-excitation was present only during the sympathetic activation caused by exercise testing and isoprenaline infusion. This phenomenon served as an indicator of significant adrenergic drive to the heart after the tilt-induced syncope. The meaning of the observed electrocardiographic changes in the course of neurocardiogenic reaction and its contribution to the understanding of the sympatho-vagal balance during vasovagal syncope is discussed. The lack of preexcitation signs during syncope and its appearance several seconds after the syncope-related sinus pause indicates sympathetic withdrawal before and shortly after the asystole. The possible pathophysiological mechanisms are discussed.

Insulated electrocardiographic electrodes. [without paste electrolyte

NASA Technical Reports Server (NTRS)

David, R. M.; Portnoy, W. A. (Inventor)

1975-01-01

An integrated system is disclosed including an insulated electrode and an impedance transformer which can be assembled in a small plastic housing and used for the acquisition of electrocardiographic data. The electrode may be employed without a paste electrolyte and may be attached to the body for extended usage without producing skin reaction. The electrode comprises a thin layer of suitable nontoxic dielectric material preferably deposited by radio frequency sputtering onto a conductive substrate. The impedance transformer preferably comprises an operational amplifier having an FET input stage connected in the unity gain configuration which provides a very low lower cut-off frequency, a high input impedance with a very small input bias current, a low output impedance, and a high signal-to-noise ratio.

Real-Time Analysis of Electrocardiographic Data for Heart Rate Turbulence

NASA Technical Reports Server (NTRS)

Greco, E. Carl, Jr.

2005-01-01

Episodes of ventricular ectopy (premature ventricular contractions, PVCs) have been reported in several astronauts and cosmonauts during space flight. Indeed, the "Occurrence of Serious Cardiac Dysrhythmias" is now NASA's #1 priority critical path risk factor in the cardiovascular area that could jeopardize a mission as well as the health and welfare of the astronaut. Epidemiological, experimental and clinical observations suggest that severe autonomic dysfunction and/or transient cardiac ischemia can initiate potentially lethal ventricular arrhythmias. On earth, Heart Rate Turbulence (HRT) in response to PVCs has been shown to provide not only an index of baroreflex sensitivity (BRS), but also more importantly, an index of the propensity for lethal ventricular arrhythmia. An HRT procedure integrated into the existing advanced electrocardiographic system under development in JSC's Human Adaptation and Countermeasures Office was developed to provide a system for assessment of PVCs in a real-time monitoring or offline (play-back) scenario. The offline heart rate turbulence software program that was designed in the summer of 2003 was refined and modified for "close to" real-time results. In addition, assistance was provided with the continued development of the real-time heart rate variability software program. These programs should prove useful in evaluating the risk for arrhythmias in astronauts who do and who do not have premature ventricular contractions, respectively. The software developed for these projects has not been included in this report. Please contact Dr. Todd Schlegel for information on acquiring a specific program.

Distinct gene-specific mechanisms of arrhythmia revealed by cardiac gene transfer of two long QT disease genes, HERG and KCNE1.

PubMed

Hoppe, U C; Marbán, E; Johns, D C

2001-04-24

The long QT syndrome (LQTS) is a heritable disorder that predisposes to sudden cardiac death. LQTS is caused by mutations in ion channel genes including HERG and KCNE1, but the precise mechanisms remain unclear. To clarify this situation we injected adenoviral vectors expressing wild-type or LQT mutants of HERG and KCNE1 into guinea pig myocardium. End points at 48-72 h included electrophysiology in isolated myocytes and electrocardiography in vivo. HERG increased the rapid component, I(Kr), of the delayed rectifier current, thereby accelerating repolarization, increasing refractoriness, and diminishing beat-to-beat action potential variability. Conversely, HERG-G628S suppressed I(Kr) without significantly delaying repolarization. Nevertheless, HERG-G628S abbreviated refractoriness and increased beat-to-beat variability, leading to early afterdepolarizations (EADs). KCNE1 increased the slow component of the delayed rectifier, I(Ks), without clear phenotypic sequelae. In contrast, KCNE1-D76N suppressed I(Ks) and markedly slowed repolarization, leading to frequent EADs and electrocardiographic QT prolongation. Thus, the two genes predispose to sudden death by distinct mechanisms: the KCNE1 mutant flagrantly undermines cardiac repolarization, and HERG-G628S subtly facilitates the genesis and propagation of premature beats. Our ability to produce electrocardiographic long QT in vivo with a clinical KCNE1 mutation demonstrates the utility of somatic gene transfer in creating genotype-specific disease models.

High efficiency processing for reduced amplitude zones detection in the HRECG signal

NASA Astrophysics Data System (ADS)

Dugarte, N.; Álvarez, A.; Balacco, J.; Mercado, G.; Gonzalez, A.; Dugarte, E.; Olivares, A.

2016-04-01

Summary - This article presents part of a more detailed research proposed in the medium to long term, with the intention of establishing a new philosophy of electrocardiogram surface analysis. This research aims to find indicators of cardiovascular disease in its early stage that may go unnoticed with conventional electrocardiography. This paper reports the development of a software processing which collect some existing techniques and incorporates novel methods for detection of reduced amplitude zones (RAZ) in high resolution electrocardiographic signal (HRECG).The algorithm consists of three stages, an efficient processing for QRS detection, averaging filter using correlation techniques and a step for RAZ detecting. Preliminary results show the efficiency of system and point to incorporation of techniques new using signal analysis with involving 12 leads.

Echocardiographic evaluation during weaning from mechanical ventilation

PubMed Central

Schifelbain, Luciele Medianeira; Vieira, Silvia Regina Rios; Brauner, Janete Salles; Pacheco, Deise Mota; Naujorks, Alexandre Antonio

2011-01-01

INTRODUCTION: Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation. OBJECTIVES: To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T‐tube; and comparing patient subgroups: success vs. failure in weaning. METHODS: Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T‐tube. Pressure support ventilation vs. T‐tube and weaning success vs. failure were compared using ANOVA and Student's t‐test. The level of significance was p<0.05. RESULTS: Twenty‐four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T‐tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation. CONCLUSION: No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T‐tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients. PMID:21437445

Diagnostic accuracy of a smartphone electrocardiograph in dogs: Comparison with standard 6-lead electrocardiography.

PubMed

Vezzosi, T; Buralli, C; Marchesotti, F; Porporato, F; Tognetti, R; Zini, E; Domenech, O

2016-10-01

The diagnostic accuracy of a smartphone electrocardiograph (ECG) in evaluating heart rhythm and ECG measurements was evaluated in 166 dogs. A standard 6-lead ECG was acquired for 1 min in each dog. A smartphone ECG tracing was simultaneously recorded using a single-lead bipolar ECG recorder. All ECGs were reviewed by one blinded operator, who judged if tracings were acceptable for interpretation and assigned an electrocardiographic diagnosis. Agreement between smartphone and standard ECG in the interpretation of tracings was evaluated. Sensitivity and specificity for the detection of arrhythmia were calculated for the smartphone ECG. Smartphone ECG tracings were interpretable in 162/166 (97.6%) tracings. A perfect agreement between the smartphone and standard ECG was found in detecting bradycardia, tachycardia, ectopic beats and atrioventricular blocks. A very good agreement was found in detecting sinus rhythm versus non-sinus rhythm (100% sensitivity and 97.9% specificity). The smartphone ECG provided tracings that were adequate for analysis in most dogs, with an accurate assessment of heart rate, rhythm and common arrhythmias. The smartphone ECG represents an additional tool in the diagnosis of arrhythmias in dogs, but is not a substitute for a 6-lead ECG. Arrhythmias identified by the smartphone ECG should be followed up with a standard ECG before making clinical decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protective Effects of Carvedilol and Vitamin C against Azithromycin-Induced Cardiotoxicity in Rats via Decreasing ROS, IL1-β, and TNF-α Production and Inhibiting NF-κB and Caspase-3 Expression

PubMed Central

El-Shitany, Nagla A.; El-Desoky, Karema

2016-01-01

The Food and Drug Administration recently warned of the fatal cardiovascular risks of azithromycin in humans. In addition, a recently published study documented azithromycin-induced cardiotoxicity in rats. This study aimed to justify the exact cardiovascular events accompanying azithromycin administration in rats, focusing on electrocardiographic, biochemical, and histopathological changes. In addition, the underlying mechanisms were studied regarding reactive oxygen species production, cytokine release, and apoptotic cell-death. Finally, the supposed protective effects of both carvedilol and vitamin C were assessed. Four groups of rats were used: (1) control, (2) azithromycin, (3) azithromycin + carvedilol, and (4) azithromycin + vitamin C. Azithromycin resulted in marked atrophy of cardiac muscle fibers and electrocardiographic segment alteration. It increased the heart rate, lactate dehydrogenase, creatine phosphokinase, malondialdehyde, nitric oxide, interleukin-1 beta (IL1-β), tumor necrosis factor alpha (TNF-α), nuclear factor kappa beta (NF-κB), and caspase-3. It decreased reduced glutathione, glutathione peroxidase, and superoxide dismutase. Carvedilol and vitamin C prevented most of the azithromycin-induced electrocardiographic and histopathological changes. Carvedilol and vitamin C decreased lactate dehydrogenase, malondialdehyde, IL1-β, TNF-α, NF-κB, and caspase-3. Both agents increased glutathione peroxidase. This study shows that both carvedilol and vitamin C protect against azithromycin-induced cardiotoxicity through antioxidant, immunomodulatory, and antiapoptotic mechanisms. PMID:27274777

On epicardial potential reconstruction using regularization schemes with the L1-norm data term.

PubMed

Shou, Guofa; Xia, Ling; Liu, Feng; Jiang, Mingfeng; Crozier, Stuart

2011-01-07

The electrocardiographic (ECG) inverse problem is ill-posed and usually solved by regularization schemes. These regularization methods, such as the Tikhonov method, are often based on the L2-norm data and constraint terms. However, L2-norm-based methods inherently provide smoothed inverse solutions that are sensitive to measurement errors, and also lack the capability of localizing and distinguishing multiple proximal cardiac electrical sources. This paper presents alternative regularization schemes employing the L1-norm data term for the reconstruction of epicardial potentials (EPs) from measured body surface potentials (BSPs). During numerical implementation, the iteratively reweighted norm algorithm was applied to solve the L1-norm-related schemes, and measurement noises were considered in the BSP data. The proposed L1-norm data term-based regularization schemes (with L1 and L2 penalty terms of the normal derivative constraint (labelled as L1TV and L1L2)) were compared with the L2-norm data terms (Tikhonov with zero-order and normal derivative constraints, labelled as ZOT and FOT, and the total variation method labelled as L2TV). The studies demonstrated that, with averaged measurement noise, the inverse solutions provided by the L1L2 and FOT algorithms have less relative error values. However, when larger noise occurred in some electrodes (for example, signal lost during measurement), the L1TV and L1L2 methods can obtain more accurate EPs in a robust manner. Therefore the L1-norm data term-based solutions are generally less perturbed by measurement noises, suggesting that the new regularization scheme is promising for providing practical ECG inverse solutions.

Multichannel techniques for motion artifacts removal from electrocardiographic signals.

PubMed

Milanesi, M; Martini, N; Vanello, N; Positano, V; Santarelli, M F; Paradiso, R; De Rossi, D; Landini, L

2006-01-01

Electrocardiographic (ECG) signals are affected by several kinds of artifacts, that may hide vital signs of interest. Motion artifacts, due to the motion of the electrodes in relation to patient skin, are particularly frequent in bioelectrical signals acquired by wearable systems. In this paper we propose different approaches in order to get rid of motion confounds. The first approach we follow starts from measuring electrode motion provided by an accelerometer placed on the electrode and use this measurement in an adaptive filtering system to remove the noise present in the ECG. The second approach is based on independent component analysis methods applied to multichannel ECG recordings; we propose to use both instantaneous model and a frequency domain implementation of the convolutive model that accounts for different paths of the source signals to the electrodes.

Myocardial Injury without Electrocardiographic Changes after a Suicide Attempt by an Overdose of Glimepiride and Zolpidem: A Case Report and Literature Review.

PubMed

Chou, Shengpu; Ayabe, Seiji; Sekine, Nobuo

2015-01-01

A 40-year-old diabetic man was admitted to our hospital for poor glycemic control. During hospitalization, he took 42 mg glimepiride and 50 mg zolpidem as a suicide attempt. The following day, the creatine kinase-MB fraction and troponin I levels were elevated to 112 IU/L and 8.77 ng/mL, respectively, without any electrocardiographic abnormalities. The patient recovered completely without any complications. Four weeks later, coronary computed tomography angiography and myocardial perfusion scintigraphy revealed moderate one-vessel coronary disease without the evidence of myocardial ischemia or old infarction. Cardiac-specific markers must be considered in sulfonylurea-induced hypoglycemic patients, particularly when the patient is unconscious and does not exhibit any clinical manifestations.

The electrocardiographic Holter monitoring in experimental veterinary practice.

PubMed

Scheer, P; Svoboda, P; Sepsi, M; Janecková, K; Doubek, J

2010-01-01

The long-term electrocardiographic recording with retrospective evaluation (Holter system) has been widely used not only in cardiology, but also in other disciplines of internal medicine and in pharmaceutical research. The Holter system can be used in mini-pig, sheep, dog, cat, rabbit, ferret, and rat. In this paper hardware, software, and anesthesia requirements are summarized with respect to the experimental work with various species. As the Holter systems work in bipolar mode, the use of bipolar leads in sagittal and transversal planes has been proved to be the most appropriate because of large amplitude of QRS complex and uncomplicated consequent automatic analysis of the record. In conclusion, Holter electrocardiography represents a simple and applicable method for monitoring the electrical activity of the heart in small animals' experimental studies.

Predictive use of routine 24-hour electrocardiography in suspected Adams-Stokes syndrome. Comparison with cardiac rhythm during symptoms.

PubMed Central

Abdon, N J; Johansson, B W; Lessem, J

1982-01-01

Using strictly defined criteria of significant arrhythmias, long term electrocardiographic recording has been evaluated for confirmation of arrhythmias as the cause of cerebral symptoms in 81 patients with suspected Adams-Stokes syndrome. Extension of long term electrocardiographic recording for more than 24 hours gives marginal additional information at a high cost. Among 43 patients monitored until symptoms appeared, non cardiogenic causes were confirmed in 20 of 22 patients because the recording showed normal rhythm during symptoms. Fifteen of 21 patients with a significant arrhythmia during an asymptomatic 24 hour recording later had the same arrhythmia during symptoms. Of 38 patients who failed to develop symptoms, 21 had a significant arrhythmia detectable within 24 hours and 23 when 48 hours of recording were analysed. PMID:7082502

Adjustment of QT dispersion assessed from 12 lead electrocardiograms for different numbers of analysed electrocardiographic leads: comparison of stability of different methods.

PubMed Central

Hnatkova, K; Malik, M; Kautzner, J; Gang, Y; Camm, A J

1994-01-01

OBJECTIVE--Normal electrocardiographic recordings were analysed to establish the influence of measurement of different numbers of electrocardiographic leads on the results of different formulas expressing QT dispersion and the effects of adjustment of QT dispersion obtained from a subset of an electrocardiogram to approximate to the true QT dispersion obtained from a complete electrocardiogram. SUBJECTS AND METHODS--Resting 12 lead electrocardiograms of 27 healthy people were investigated. In each lead, the QT interval was measured with a digitising board and QT dispersion was evaluated by three formulas: (A) the difference between the longest and the shortest QT interval among all leads; (B) the difference between the second longest and the second shortest QT interval; (C) SD of QT intervals in different leads. For each formula, the "true" dispersion was assessed from all measurable leads and then different combinations of leads were omitted. The mean relative differences between the QT dispersion with a given number of omitted leads and the "true" QT dispersion (mean relative errors) and the coefficients of variance of the results of QT dispersion obtained when omitting combinations of leads were compared for the different formulas. The procedure was repeated with an adjustment of each formula dividing its results by the square root of the number of measured leads. The same approach was used for the measurement of QT dispersion from the chest leads including a fourth formula (D) the SD of interlead differences weighted according to the distances between leads. For different formulas, the mean relative errors caused by omitting individual electrocardiographic leads were also assessed and the importance of individual leads for correct measurement of QT dispersion was investigated. RESULTS--The study found important differences between different formulas for assessment of QT dispersion with respect to compensation for missing measurements of QT interval. The standard max-min formula (A) performed poorly (mean relative errors of 6.1% to 18.5% for missing one to four leads) but was appropriately adjusted with the factor of 1/square root of n (n = number of measured leads). In a population of healthy people such an adjustment removed the systematic bias introduced by missing leads of the 12 lead electrocardiogram and significantly reduced the mean relative errors caused by the omission of several leads. The unadjusted SD was the optimum formula (C) for the analysis of 12 lead electrocardiograms, and the weighted standard deviation (D) was the optimum for the analysis of six lead chest electrocardiograms. The coefficients of variance of measurements of QT dispersion with different missing leads were very large (about 3 to 7 for one to four missing leads). Independently of the formula for measurement of QT dispersion, omission of different leads produced substantially different relative errors. In 12 lead electrocardiograms the largest relative errors (> 10%) were caused by omitting lead aVL or lead V1. CONCLUSIONS--Because of the large coefficients of variance, the concept of adjusting the QT dispersion for different numbers of electrocardiographic leads used in its assessment is difficult if not impossible to fulfil. Thus it is likely to be more appropriate to assess QT dispersion from standardised constant sets of electrocardiographic leads. PMID:7833200

Cardiovascular examinations and observations of deconditioning during the Space Shuttle orbital flight test program

NASA Technical Reports Server (NTRS)

Bungo, M. W.; Johnson, P. C., Jr.

1983-01-01

During the first four flights of the Space Shuttle, cardiovascular data were obtained on each crewmember as part of the operational medicine requirements for crew health and safety. From monitoring blood pressure and electrocardiographic data, it was possible to estimate the degree of deconditioning imposed by exposure to the microgravity environment. For this purpose, a quantitative cardiovascular index of deconditioning (CID) was derived to aid the clinician in his assessment. Isotonic saline was then investigated as a countermeasure against orthostatic intolerance and found to be effective in partially reversing the hemodynamic consequences. It was observed that the space flight environment of reentry might potentially be arrhythmogenic in at least one individual.

Genome-wide association studies in cardiac electrophysiology: recent discoveries and implications for clinical practice.

PubMed

Milan, David J; Lubitz, Steven A; Kääb, Stefan; Ellinor, Patrick T

2010-08-01

Genome-wide association studies have been increasingly used to study the genetics of complex human diseases. Within the field of cardiac electrophysiology, this technique has been applied to conditions such as atrial fibrillation, and several electrocardiographic parameters including the QT interval. While these studies have identified multiple genomic regions associated with each trait, questions remain, including the best way to explore the pathophysiology of each association and the potential for clinical utility. This review will summarize recent genome-wide association study results within cardiac electrophysiology and discuss their broader implications in basic science and clinical medicine. Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Risk for Clinically Relevant Adverse Cardiac Events in Patients With Chest Pain at Hospital Admission.

PubMed

Weinstock, Michael B; Weingart, Scott; Orth, Frank; VanFossen, Douglas; Kaide, Colin; Anderson, Judy; Newman, David H

2015-07-01

Patients with potentially ischemic chest pain are commonly admitted to the hospital or observed after a negative evaluation in the emergency department (ED) owing to concern about adverse events. Previous studies have looked at 30-day mortality, but no current large studies have examined the most important information regarding ED disposition: the short-term risk for a clinically relevant adverse cardiac event (including inpatient ST-segment elevation myocardial infarction, life-threatening arrhythmia, cardiac or respiratory arrest, or death). To determine the incidence of clinically relevant adverse cardiac events in patients hospitalized for chest pain with 2 troponin-negative findings, nonconcerning initial ED vital signs, and nonischemic, interpretable electrocardiographic findings. We conducted a blinded data review of 45,416 encounters obtained from a prospectively collected database enrolling adult patients admitted or observed with the following inclusion criteria: (1) primary presenting symptom of chest pain, chest tightness, chest burning, or chest pressure and (2) negative findings for serial biomarkers. Data were collected and analyzed from July 1, 2008, through June 30, 2013, from the EDs of 3 community teaching institutions with an aggregate census of more than 1 million visits. We analyzed data extracted by hypothesis-blinded abstractors. The primary outcome was a composite of life-threatening arrhythmia, inpatient ST-segment elevation myocardial infarction, cardiac or respiratory arrest, or death during hospitalization. Of the 45,416 encounters, 11,230 met criteria for inclusion. Mean patient age was 58.0 years. Of the 11 230 encounters, 44.83% of patients arrived by ambulance and 55.00% of patients were women. Relevant history included hypertension in 46.00%, diabetes mellitus in 19.72%, and myocardial infarction in 13.16%. The primary end point occurred in 20 of the 11 230 patients (0.18% [95% CI, 0.11%-0.27%]). After excluding patients with abnormal vital signs, electrocardiographic ischemia, left bundle branch block, or a pacemaker rhythm, we identified a primary end point event in 4 of 7266 patients (0.06% [95% CI, 0.02%-0.14%]). Of these events, 2 were noncardiac and 2 were possibly iatrogenic. In adult patients with chest pain admitted with 2 negative findings for serial biomarkers, nonconcerning vital signs, and nonischemic electrocardiographic findings, short-term clinically relevant adverse cardiac events were rare and commonly iatrogenic, suggesting that routine inpatient admission may not be a beneficial strategy for this group.

Variability in surface ECG morphology: signal or noise?

NASA Technical Reports Server (NTRS)

Smith, J. M.; Rosenbaum, D. S.; Cohen, R. J.

1988-01-01

Using data collected from canine models of acute myocardial ischemia, we investigated two issues of major relevance to electrocardiographic signal averaging: ECG epoch alignment, and the spectral characteristics of the beat-to-beat variability in ECG morphology. With initial digitization rates of 1 kHz, an iterative a posteriori matched filtering alignment scheme, and linear interpolation, we demonstrated that there is sufficient information in the body surface ECG to merit alignment to a precision of 0.1 msecs. Applying this technique to align QRS complexes and atrial pacing artifacts independently, we demonstrated that the conduction delay from atrial stimulus to ventricular activation may be so variable as to preclude using atrial pacing as an alignment mechanism, and that this variability in conduction time be modulated at the frequency of respiration and at a much lower frequency (0.02-0.03Hz). Using a multidimensional spectral technique, we investigated the beat-to-beat variability in ECG morphology, demonstrating that the frequency spectrum of ECG morphological variation reveals a readily discernable modulation at the frequency of respiration. In addition, this technique detects a subtle beat-to-beat alternation in surface ECG morphology which accompanies transient coronary artery occlusion. We conclude that physiologically important information may be stored in the variability in the surface electrocardiogram, and that this information is lost by conventional averaging techniques.

Intracardiac electrocardiographic assessment of precordial TASER shocks in human subjects: A pilot study.

PubMed

Stopyra, Jason P; Winslow, James E; Fitzgerald, David M; Bozeman, William P

2017-11-01

Case reports of cardiac arrest in temporal proximity to Conducted Electrical Weapon(CEW) exposure raise legitimate concerns about this as a rare possibility. In this pilot study, we respectfully navigate the oversight and regulatory hurdles and demonstrate the intra-shock electrocardiographic effects of an intentional transcardiac CEW discharge using subcutaneous probes placed directly across the precordium of patients with a previously implanted intracardiac EKG sensing lead. Adults scheduled to undergo diagnostic EP studies or replacement of an implanted cardiac device were enrolled. Sterile subcutaneous electrodes were placed at the right sternoclavicular junction and the left lower costal margin at the midclavicular line. A standard police issue TASER Model X26 CEW was attached to the subcutaneous electrodes and a 5 s discharge was delivered. Continuous surface and intracardiac EKG monitoring was performed. A total of 157 subjects were reviewed for possible inclusion and 21 were interviewed. Among these, 4 subjects agreed and completed the study protocol. All subjects tolerated the 5 s CEW discharge without clinical complications. There were no significant changes in mean heart rate or blood pressure. Interrogation of the devices after CEW discharge revealed no ventricular pacing, dysrhythmias, damage or interference with the implanted devices. In this pilot study, we have successfully navigated the regulatory hurdles and demonstrated the feasibility of performing intracardiac EKG recording during intentional precordial CEW discharges in humans. While no CEW-associated dysrhythmias were noted, the size of this preliminary dataset precludes making conclusions about the risk of such events. Larger studies are warranted and should consider exploring variations of the CEW electrode position in relation to the cardiac silhouette. Copyright © 2017. Published by Elsevier Ltd.

Localization of premature ventricular contractions from the papillary muscles using the standard 12-lead electrocardiogram: a feasibility study using a novel cardiac isochrone positioning system.

PubMed

van Dam, Peter M; Boyle, Noel G; Laks, Michael M; Tung, Roderick

2016-12-01

The precise localization of the site of origin of a premature ventricular contraction (PVC) prior to ablation can facilitate the planning and execution of the electrophysiological procedure. In clinical practice, the targeted ablation site is estimated from the standard 12-lead ECG. The accuracy of this qualitative estimation has limitations, particularly in the localization of PVCs originating from the papillary muscles. Clinical available electrocardiographic imaging (ECGi) techniques that incorporate patient-specific anatomy may improve the localization of these PVCs, but require body surface maps with greater specificity for the epicardium. The purpose of this report is to demonstrate that a novel cardiac isochrone positioning system (CIPS) program can accurately detect the specific location of the PVC on the papillary muscle using only a 12-lead ECG. Cardiac isochrone positioning system uses three components: (i) endocardial and epicardial cardiac anatomy and torso geometry derived from MRI, (ii) the patient-specific electrode positions derived from an MRI model registered 3D image, and (iii) the 12-lead ECG. CIPS localizes the PVC origin by matching the anatomical isochrone vector with the ECG vector. The predicted PVC origin was compared with the site of successful ablation or stimulation. Three patients who underwent electrophysiological mapping and ablation of PVCs originating from the papillary muscles were studied. CIPS localized the PVC origin for all three patients to the correct papillary muscle and specifically to the base, mid, or apical region. A simplified form of ECGi utilizing only 12 standard electrocardiographic leads may facilitate accurate localization of the origin of papillary muscle PVCs. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

["Pericarditis epistenocardica" as as a marker of extensive myocardial infarction. Clinical, electrocardiographic and enzymatic study (author's transl)].

PubMed

Oddone, A; Tommasini, G; Cobelli, F; Birolli, M; Orlandi, M

1977-08-01

Pericarditis may complicate the early phase of myocardial infarction (MI). It occurs when necrosis involves the epicardial surface. To verify if pericarditis may be regarded as a marker of extensive MI, 60 patients with anterior or inferior MI admitted to the Coronary Care Unit within 6 hours from onset of symptoms, were studied by clinical, electrocardiographic and enzymatic parameters. 20 patients developed left ventricular failure (LVF) assessed by clinical, radiologic and hemodynamic indexes (15 mmHg has been considered the upper normal value for mean wedge pulmonary pressure). 9 of the 11 patients with pericarditis (PP) had LVF, versus 11 of the 49 non PP group (P = 0.002). Life threatening arrhythmias (ventricular tachicardia and fibrillation) appeared in 5 of the 11 PP versus 7 of the 49 non PP group (P = 0.04). No significant difference has been found between the two groups concerning the inhospital mortality. In a follow-up of 3 to 18 months, no difference in mortality was observed, while the functional recovery in the PP group was significantly worse (I and II versus III and IV New York Heart Association classes P = 0.003). Higher sigmaST values were found in precordial maps of the PP group, on admission (P = 0.03). After a deep spontaneous fall, sigmaST showed a reelevation which was similar in the two groups. SigmaR showed a greater % decrease however not statistically significant in PP. Creatinekinase enzymatic infarct size was significantly higher in PP group (P = 0.0002). It is concluded that pericarditis is a clinical marker of extensive MI and may be useful in evaluating prognosis and effectiveness of therapeutic interventions in MI.

Electrocardiographic Impact of Myocardial Diffuse Fibrosis and Scar: MESA (Multi-Ethnic Study of Atherosclerosis)

PubMed Central

Inoue, Yuko Y.; Ambale-Venkatesh, Bharath; Mewton, Nathan; Volpe, Gustavo J.; Ohyama, Yoshiaki; Sharma, Ravi K.; Wu, Colin O.; Liu, Chia-Ying; Bluemke, David A.; Soliman, Elsayed Z.; Lima, João A. C.

2017-01-01

Purpose To examine the associations of myocardial diffuse fibrosis and scar with surface electrocardiographic (ECG) parameters in individuals free of prior coronary heart disease in four different ethnicities. Materials and Methods This prospective cross-sectional study was approved by the institutional review boards, and all participants gave informed consent. A total of 1669 participants in the Multi-Ethnic Study of Atherosclerosis, or MESA, who were free of prior myocardial infarction underwent both ECG and cardiac magnetic resonance imaging. In individuals without a late gadolinium enhancement–defined myocardial scar (n = 1131), T1 mapping was used to assess left ventricular (LV) interstitial diffuse fibrosis. The associations of LV diffuse fibrosis or myocardial scar with ECG parameters (QRS voltage, QRS duration, and corrected QT interval [QTc]) were evaluated by using multivariable regression analyses adjusted for demographic data, risk factors for scar, LV end-diastolic volume, and LV mass. Results The mean age of the 1669 participants was 67.4 years ± 8.7 (standard deviation); 49.8% were women. Lower postcontrast T1 time at 12 minutes was significantly associated with lower QRS Sokolow-Lyon voltage (β = 15.1 µV/10 msec, P = .004), lower QRS Cornell voltage (β = 9.2 µV/10 msec, P = .031), and shorter QRS duration (β = 0.16 msec/10 msec, P = .049). Greater extracellular volume (ECV) fraction was also significantly associated with lower QRS Sokolow-Lyon voltage (β = −35.2 µV/1% ECV increase, P < .001) and Cornell voltage (β = −23.7 µV/1% ECV increase, P < .001), independent of LV structural indexes. In contrast, the presence of LV scar (n = 106) was associated with longer QTc (β = 4.3 msec, P = .031). Conclusion In older adults without prior coronary heart disease, underlying greater LV diffuse fibrosis is associated with lower QRS voltage and shorter QRS duration at surface ECG, whereas clinically unrecognized myocardial scar is associated with a longer QT interval. © RSNA, 2016 Online supplemental material is available for this article. PMID:27740904

Examining QRS amplitude criteria for electrocardiographic left ventricular hypertrophy in recommendations for screening criteria in athletes.

PubMed

Singla, Varun; Jindal, Akash; Pargaonkar, Vedant; Soofi, Muhammad; Wheeler, Matthew; Froelicher, Victor

2015-01-01

Current guidelines for interpretation of the ECGs of athletes recommend that isolated R and S wave amplitudes that exceed traditional criteria for left ventricular hypertrophy be accepted as a physiological response to exercise training. This is based on training and echocardiographic studies but not on long term follow up. Demonstration of the prognostic characteristics of the amplitude criteria in a non-athletic population could support the current guidelines. To evaluate the prognostic value of the R and S wave voltage criteria for electrocardiographic left ventricular hypertrophy (ECG-LVH) in an ambulatory clinical population. The target population consisted of 20,903 ambulatory subjects who had ECGs recorded between 1987 and 1999 and were followed for cardiovascular death until 2013. During the mean follow up of 17 years, there were 881 cardiovascular deaths. The mean age was 43 ± 10, 91% were male and 16% were African American. Of the 2482 (12%) subjects who met the Sokolow-Lyon criteria, 241 (1.2%) subjects with left ventricular (LV) strain had an HR of 5.4 (95% CI 4.1-7.2, p<0.001), while 2241 (11%) subjects without strain had an HR of 1.4 (95% CI 1.2-1.8, p<0.001). Of the 4836 (23%) subjects who met the Framingham voltage criteria, 350 (2%) subjects with LV strain had an HR of 5.1 (95% CI 4.0-6.5, p<0.001), while 4486 (22%) subjects without strain had an HR of 1.1 (95% CI 0.9-1.3, p=0.26). The individual components of the Romhilt-Estes had HRs ranging from 1.4 to 3.6, with only the voltage component not being significant (HR 1.1, 95% CI 0.9-1.5, p=0.35). This study demonstrates that the R and S wave voltage criteria components of most of the original classification schema for electrocardiographic left ventricular hypertrophy are not predictive of CV mortality. Our findings support the current guidelines for electrocardiographic screening of athletes. Copyright © 2015 Elsevier Inc. All rights reserved.

XML-BSPM: an XML format for storing Body Surface Potential Map recordings.

PubMed

Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George

2010-05-14

The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual solutions and inspire existing formats such as DICOM, SCP-ECG and aECG to support the storage of BSPMs. In summary, this research provides initial ground work for creating a complete BSPM management system.

Development of a Multi-Channel, High Frequency QRS Electrocardiograph

NASA Technical Reports Server (NTRS)

DePalma, Jude L.

2003-01-01

With the advent of the ISS era and the potential requirement for increased cardiovascular monitoring of crewmembers during extended EVAs, NASA flight surgeons would stand to benefit from an evolving technology that allows for a more rapid diagnosis of myocardial ischemia compared to standard electrocardiography. Similarly, during the astronaut selection process, NASA flight surgeons and other physicians would also stand to benefit from a completely noninvasive technology that, either at rest or during maximal exercise tests, is more sensitive than standard ECG in identifying the presence of ischemia. Perhaps most importantly, practicing cardiologists and emergency medicine physicians could greatly benefit from such a device as it could augment (or even replace) standard electrocardiography in settings where the rapid diagnosis of myocardial ischemia (or the lack thereof) is required for proper clinical decision-making. A multi-channel, high-frequency QRS electrocardiograph is currently under development in the Life Sciences Research Laboratories at JSC. Specifically the project consisted of writing software code, some of which contained specially-designed digital filters, which will be incorporated into an existing commercial software program that is already designed to collect, plot and analyze conventional 12-lead ECG signals on a desktop, portable or palm PC. The software will derive the high-frequency QRS signals, which will be analyzed (in numerous ways) and plotted alongside of the conventional ECG signals, giving the PC-viewing clinician advanced diagnostic information that has never been available previously in all 12 ECG leads simultaneously. After the hardware and software for the advanced digital ECG monitor have been fully integrated, plans are to use the monitor to begin clinical studies both on healthy subjects and on patients with known coronary artery disease in both the outpatient and hospital settings. The ultimate goal is to get the technology out into the clinical world, where it has the potential to save lives.

Genetics Home Reference: Woodhouse-Sakati syndrome

MedlinePlus

... low amounts of hormones that direct sexual development (hypogonadism), which typically becomes apparent during adolescence. Without hormone ... Resources Genetic Testing (1 link) Genetic Testing Registry: Hypogonadism, diabetes mellitus, alopecia, mental retardation and electrocardiographic abnormalities ...

Acute aortic syndromes: new insights from electrocardiographically gated computed tomography.

PubMed

Fleischmann, Dominik; Mitchell, R Scott; Miller, D Craig

2008-01-01

The development of retrospective electrocardiographic (ECG)-gating has proved to be a diagnostic and therapeutic boon for computed tomography (CT) imaging of patients with acute thoracic aortic diseases, such as aortic dissection/intramural hematoma (AD/IMH), penetrating atherosclerotic ulcer (APU), and ruptured/leaking aneurysm. The notorious pulsation motion artifacts in the ascending aorta confounding regular CT scanning can be eliminated, and involvement of the sinuses of Valsalva, the valve cusps, the aortic annulus, and the coronary arteries in aortic dissection can be clearly depicted or excluded. Motion-free images also allow reliable identification of the site of the primary intimal tear, the location, and extent of the intimomedial flap, and branch artery involvement. ECG-gated CTA also allows the detection of more subtle lesions and variants of aortic dissection, which may ultimately expand our understanding of these complex, life-threatening disorders.

Electrocardiographically gated 16-section CT of the thorax: cardiac motion suppression.

PubMed

Hofmann, Lars K; Zou, Kelly H; Costello, Philip; Schoepf, U Joseph

2004-12-01

Thirty patients underwent 16-section multi-detector row computed tomographic (CT) angiography of the thorax with retrospective electrocardiographic gating. Institutional review board approval was obtained for retrospective analysis of CT scan data and records; patient informed consent was not required. Images reconstructed at six different time points (0%, 20%, 40%, 50%, 60%, 80%) within the R-R interval on the electrocardiogram were analyzed by two radiologists for diagnostic quality, to identify suitable reconstruction intervals for optimal suppression of cardiac motion. Five regions of interest (left coronary artery, aortic root, ascending and descending aorta, pulmonary arteries) were evaluated. Best image quality was achieved by referencing image reconstruction to middiastole (50%-60%) for the left coronary artery, aortic root, and ascending aorta. The pulmonary arteries are best displayed during mid- to late diastole (80%). (c) RSNA, 2004

Lifetime endogenous estrogen exposure and electrocardiographic frontal T axis changes in postmenopausal women.

PubMed

Atsma, Femke; van der Schouw, Yvonne T; Grobbee, Diederick E; Kors, Jan A; Bartelink, Marie-Louise E L

2009-08-20

The protective effect of endogenous estrogens in cardiovascular disease may in part originate from effects of circulating estrogens on the electrophysiological properties of the myocardium. The aim of this study was to investigate the relation between reproductive factors and the electrocardiographic frontal T axis in postmenopausal women. Cohort study. The study was conducted at the University Medical Center Utrecht. In total, 998 postmenopausal women were included. Information of women's reproductive life was obtained by a questionnaire. Electrocardiographic frontal T axes were categorized as normal (25-65 degrees) or abnormal (-180 degrees to 24 degrees and 66-180 degrees). Logistic regression analysis was used to assess the relationship between reproductive factors and the frontal T axis. Moreover, the effect of the lifetime cumulative number of menstrual cycles, a composite measure of all reproductive factors, on the frontal T axis was investigated. The mean age was 66.0 (+/-5.6) years and 15.3% had T-axes abnormalities. Later menopausal age decreased the risk on frontal T-axis abnormalities; the multivariable adjusted odds ratio was 0.97 (95% CI: 0.94-0.99) per year increasing menopause. For the lifetime cumulative number of menstrual cycles the age-adjusted odds ratio was 0.84 (95% CI: 0.75-0.99) per 100 menstrual cycles increase. Later age at menopause and increasing lifetime cumulative number of menstrual cycles decreased the risk on frontal T-axis changes. This supports the view that estrogens may protect against ventricular repolarization disturbances.

Electromagnetic energy radiated from mobile phone alters electrocardiographic records of patients with ischemic heart disease.

PubMed

Alhusseiny, Ah; Al-Nimer, Ms; Majeed, Ad

2012-07-01

Electromagnetic energy radiated from mobile phones did not show significant effect on the blood pressure, heart rate, and electrocardiographic (ECG) parameters in animals and humans. This study aimed to investigate the effect of radiofrequency of mobile phone on the electrocardiographic parameters in patients with history of ischemic heart disease, taking into consideration the gender factor. A total number of 356 participants (129 males and 227 females) were admitted in this study. They were grouped into: subjects without cardiac diseases (Group I), patients with ischemic heart disease (Group II), and patients with history of cardiac diseases not related to myocardial ischemia (Group III). Electrocardiogram was obtained from each patient when the mobile phone was placed at the belt level and over precordium in turn-off mode (baseline) and turn-on mode for 40 sec ringing. The records of ECG were electronically analyzed. Prolongation of QTc interval was significantly observed in male gender of Groups I and III (P < 0.001). Male patients of Group II showed significant QTc interval prolongation (P = 0.01) and changes in the voltage criteria (P = 0.001). These changes were not observed in female patients with ischemic heart disease. The position of mobile at the belt level or over the precordium showed effects on the heart. The radiofrequency of cell phone prolongs the QT interval in human beings and it interferes with voltage criteria of ECG records in male patients with myocardial ischemia.

Accuracy of remote electrocardiogram interpretation with the use of Google Glass technology.

PubMed

Jeroudi, Omar M; Christakopoulos, George; Christopoulos, George; Kotsia, Anna; Kypreos, Megan A; Rangan, Bavana V; Banerjee, Subhash; Brilakis, Emmanouil S

2015-02-01

We sought to investigate the accuracy of remote electrocardiogram (ECG) interpretation using Google Glass (Google, Mountain View, California). Google Glass is an optical head mounted display device with growing applications in medicine. We compared interpretation of 10 ECGs with 21 clinically important findings by faculty and fellow cardiologists by (1) viewing the electrocardiographic image at the Google Glass screen; (2) viewing a photograph of the ECG taken using Google Glass and interpreted on a mobile device; (3) viewing the original paper ECG; and (4) viewing a photograph of the ECG taken with a high-resolution camera and interpreted on a mobile device. One point was given for identification of each correct finding. Subjective rating of the user experience was also recorded. Twelve physicians (4 faculty and 8 fellow cardiologists) participated. The average electrocardiographic interpretation score (maximum 21 points) as viewed through the Google Glass, Google Glass photograph on a mobile device, on paper, and high-resolution photograph on a mobile device was 13.5 ± 1.8, 16.1 ± 2.6, 18.3 ± 1.7, and 18.6 ± 1.5, respectively (p = 0.0005 between Google Glass and mobile device, p = 0.0005 between Google Glass and paper, and p = 0.002 between mobile device and paper). Of the 12 physicians, 9 (75%) were dissatisfied with ECGs viewing on the prism display of Google Glass. In conclusion, further improvements are needed before Google Glass can be reliably used for remote electrocardiographic analysis. Published by Elsevier Inc.

[Effect of underground work on cardiovascular system 
in coal miners].

PubMed

Lai, Zhiwei; Wang, Xiaoye; Tan, Hongzhuan; Huang, Yaoyu; Lu, Changcheng

2015-10-01

To study the effect of underground work on cardiovascular system health in coal miners.
 Male coal miners, who received electrocardiographic examinations between June, 2013 and August, 2014 in Hunan Prevention and Treatment Institute for Occupational Diseases to exclude pneumoconiosis, were enrolled for this study (n=3 134). Miners with 2 years or more underground work experience were selected as the exposed group (n=2 370), while miners without underground work experience were selected as the control group (n=764). The prevalence of electrocardiographic abnormalities and the influential factors were compared between the 2 groups.
 The prevalences of electrocardiographic abnormalities, hypertension, heart rate abnormalities and cardiovascular system abnormalities in the exposed group vs the control group were 37.6% vs 25.4%, 20.5% vs 13.4%, 5.7% vs 6.0%, 49.8% vs 35.2%, respectively. The cardiovascular system abnormalities were correlated with the underground work (OR=3.128, 95% CI: 1.969-4.970), the underground work experience (OR=1.205, 95% CI: 1.070-1.358) and the type of works (mining worker OR=1.820, 95% CI: 1.527-2.169; auxiliary worker OR=1.937, 95% CI: 1.511-2.482; other worker OR=3.291, 95%CI: 2.120-5.109).
 Underground work may increase the prevalence of cardiovascular system abnormalities for coal miners. The longer the coal miners work in underground, the higher the risk of the cardiovascular system abnormalities they are.

Electrocardiography as a Tool for Validating Myocardial Ischemia–Reperfusion Procedures in Mice

PubMed Central

Preda, Mihai B; Burlacu, Alexandrina

2010-01-01

This paper evaluates the modifications induced by ischemia and ischemia–reperfusion in mice after permanent or transient, respectively, ligation of the left coronary artery and establishes a correlation among the extent of ischemia, electrocardiograph features, and infarct size. The left coronary artery was ligated 1 mm distal from the tip of the left auricle. Histologic analysis revealed that 30-min ischemia (n = 9) led to infarction involving 9.7% ± 0.5% of the left ventricle, whereas 1-h ischemia (n = 9) resulted in transmural infarction of 16.1% ± 4.6% of the left ventricle. In contrast, 24-h ischemia (n = 8) and permanent ischemia (n = 8) induced similarly sized infarcts (33% ± 2% and 31.8% ± 0.7%, respectively), suggesting ineffective reperfusion after 24-h ischemia. Electrocardiography revealed that ligation of the left coronary artery led to ST height elevation (204 compared with 14 μV) and QTc prolongation (136 compared with 76 ms). Both parameters rapidly normalized on reperfusion, demonstrating that electrocardiography was important for validating correct ligation and reperfusion. In addition, electrocardiography predicted the severity of the myocardial damage induced by ischemia. Our results show that electrocardiographic changes present after 30-min ischemia were reversed on reperfusion; however, prolonged ischemia induced pathologic electrocardiographic patterns that remained even after reperfusion. The mouse model of myocardial ischemia–reperfusion can be improved by using electrocardiography to validate ligation and reperfusion during surgery and to predict the severity of infarction. PMID:21262130

Prophylactic accessory-pathway ablation in asymptomatic patients with a Wolff-Parkinson-White electrocardiographic pattern.

PubMed

Ozenc, S; Iscen, S; Kibrisli, E; Tok, D; Parlak, A; Altinel, O; Altinel, S

2014-01-01

The optimal approach is controversial in asymptomatic patients who are coincidentally found to have evidence of an accessory pathway (AP) on an ECG. The risk of sudden cardiac death (SCD) is low, and the risk of developing symptoms also appears to be low, although a wide range of incidences have been reported. In our trial, we tested the hypothesis that if prophylactic accessory-pathway ablation performed at the time of the initial electrophysiological testing would improve the long-term outcome in asymptomatic patients with a Wolff-Parkinson-White electrocardiographic pattern. Recruitment of patients began on February 1, 2004, and ended on February 5, 2009. All 110 asymptomatic patients were hospitalized and underwent electrophysiological testing the same day to assess the inducibility of atrioventricular reciprocating tachycardia. The anterograde effective refractory period of the accessory pathway was defined as the longest coupling interval at which anterograde block in the bypass tract was observed. For the statistical analysis, the statistical software SPSS version 15.0 for Windows (SPSS Inc., Chicago, IL, USA). Of 110 asymptomatic patients with a Wolff-Parkinson-White electrocardiographic pattern, 80 patients were ablated. Ablation group consisted of these patients. Control group consisted of remaining 30 and were divided into two groups according to the anterograde effective refractory period of the accessory pathway. There was no significant difference between three groups in terms of arrhythmic events (p: 0.58). Asymptomatic patients with the Wolff-Parkinson-White syndrome do not require prophylactic ablation, since they remain asymptomatic for many years.

Prevalence of electrocardiographic abnormalities in West-Asian and African male athletes.

PubMed

Wilson, M G; Chatard, J C; Carre, F; Hamilton, B; Whyte, G P; Sharma, S; Chalabi, H

2012-04-01

To evaluate the electrocardiographic (ECG) characteristics of West-Asian, black and Caucasian male athletes competing in Qatar using the 2010 recommendations for 12-lead ECG interpretation by the European Society of Cardiology (ESC). Cardiovascular screening with resting 12-lead ECG analysis of 1220 national level athletes (800 West-Asian, 300 black and 120 Caucasian) and 135 West-Asian controls was performed. Ten per cent of athletes presented with 'uncommon' ECG findings. Black African descent was an independent predictor of 'uncommon' ECG changes when compared with West-Asian and Caucasian athletes (p<0.001). Black athletes also demonstrated a significantly greater prevalence of lateral T-wave inversions than both West-Asian and Caucasian athletes (6.1% vs 1.6% and 0%, p<0.05). The rate of 'uncommon' ECG changes between West-Asian and Caucasian athletes was comparable (7.9% vs 5.8%, p>0.05). Seven athletes (0.6%) were identified with a disease associated with sudden death; this prevalence was two times higher in black athletes than in West-Asian athletes (1% vs 0.5%), and no cases were reported in Caucasian athletes and West-Asian controls. Eighteen West-Asian and black athletes were identified with repolarisation abnormalities suggestive of a cardiomyopathy, but ultimately, none were diagnosed with a cardiac disease. West-Asian and Caucasian athletes demonstrate comparable rates of ECG findings. Black African ethnicity is positively associated with increased frequencies of 'uncommon' ECG traits. Future work should examine the genetic mechanisms behind ECG and myocardial adaptations in athletes of diverse ethnicity, aiding in the clinical differentiation between physiological remodelling and potential cardiomyopathy or ion channel disorders.

Electrocardiographic Predictors of Incident Atrial Fibrillation

PubMed Central

Nguyen, Kaylin T.; Vittinghoff, Eric; Dewland, Thomas A.; Mandyam, Mala C.; Stein, Phyllis K.; Soliman, Elsayed Z.; Heckbert, Susan R.; Marcus, Gregory M.

2017-01-01

Atrial fibrillation (AF) is likely secondary to multiple different pathophysiological mechanisms that are increasingly, but incompletely understood. Motivated by the hypothesis that 3 previously described electrocardiographic (ECG) predictors of AF identify distinct AF mechanisms, we sought to determine if these ECG findings independently predict incident disease. Among Cardiovascular Health Study participants without prevalent AF, we determined whether left anterior fascicular block (LAFB), a prolonged QTC, and atrial premature complexes (APCs) each predicted AF after adjusting for each other. We then calculated the attributable risk in the exposed for each ECG marker. LAFB and QTC intervals were assessed on baseline 12-lead ECG (n=4,696). APC count was determined using 24-hour Holter recordings obtained in a random subsample (n=1,234). After adjusting for potential confounders and each ECG marker, LAFB (hazard ratio [HR. 2.1, 95% confidence interval [CI. 1.1–3.9, p=0.023), a prolonged QTC (HR 2.5, 95% CI 1.4–4.3, p=0.002), and every doubling of APC count (HR 1.2, 95% CI 1.1–1.3, p<0.001) each remained independently predictive of incident AF. The attributable risk of AF in the exposed was 35% (95% CI 13–52%) for LAFB, 25% (95% CI 0.6–44%) for a prolonged QTC, and 34% (95% CI 26–42%) for APCs. In conclusion, in a community-based cohort, 3 previously established ECG-derived AF predictors were each independently associated with incident AF, suggesting they may represent distinct mechanisms underlying the disease. PMID:27448684

Development of a portable wireless system for bipolar concentric ECG recording

NASA Astrophysics Data System (ADS)

Prats-Boluda, G.; Ye-Lin, Y.; Bueno Barrachina, J. M.; Senent, E.; Rodriguez de Sanabria, R.; Garcia-Casado, J.

2015-07-01

Cardiovascular diseases (CVDs) remain the biggest cause of deaths worldwide. ECG monitoring is a key tool for early diagnosis of CVDs. Conventional monitors use monopolar electrodes resulting in poor spatial resolution surface recordings and requiring extensive wiring. High-spatial resolution surface electrocardiographic recordings provide valuable information for the diagnosis of a wide range of cardiac abnormalities, including infarction and arrhythmia. The aim of this work was to develop and test a wireless recording system for acquiring high spatial resolution ECG signals, based on a flexible tripolar concentric electrode (TCE) without cable wiring or external reference electrode which would make more comnfortable its use in clinical practice. For this, a portable, wireless sensor node for analogue conditioning, digitalization and transmission of a bipolar concentric ECG signal (BC-ECG) using a TCE and a Mason-likar Lead-I ECG (ML-Lead-I ECG) signal was developed. Experimental results from a total of 32 healthy volunteers showed that the ECG fiducial points in the BC-ECG signals, recorded with external and internal reference electrode, are consistent with those of simultaneous ML-Lead-I ECG. No statistically significant difference was found in either signal amplitude or morphology, regardless of the reference electrode used, being the signal-to-noise similar to that of ML-Lead-I ECG. Furthermore, it has been observed that BC-ECG signals contain information that could not available in conventional records, specially related to atria activity. The proposed wireless sensor node provides non-invasive high-local resolution ECG signals using only a TCE without additional wiring, which would have great potential in medical diagnosis of diseases such as atrial or ventricular fibrillations or arrhythmias that currently require invasive diagnostic procedures (catheterization).

76 FR 43582 - Cardiovascular Devices; Classification of Electrocardiograph Electrodes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-21

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 870 [Docket No. FDA-2007-N-0092] (Formerly Docket No. 2007N-0308) Cardiovascular Devices; Classification of... amended as follows: [[Page 43585

Mangifera indica L. leaf extract alleviates doxorubicin induced cardiac stress

PubMed Central

Bhatt, Laxit; Joshi, Viraj

2017-01-01

Aim: The study was undertaken to evaluate the cardioprotective effect of the alcoholic leaf extract of Mangifera indica L. against cardiac stress caused by doxorubicin (DOX). Materials and Methods: Rats were treated with 100 mg/kg of M. indica leaf extract (MILE) in alone and interactive groups for 21 days. Apart from the normal and MILE control groups, all the groups were subjected to DOX (15 mg/kg, i.p.) toxicity for 21 days and effects of different treatments were analyzed by changes in serum biomarkers, tissue antioxidant levels, electrocardiographic parameters, lipid profile, and histopathological evaluation. Results: The MILE treated group showed decrease in serum biomarker enzyme levels and increase in tissue antioxidants levels. Compared to DOX control group, MILE treated animals showed improvement in lipid profile, electrocardiographic parameters, histological score, and mortality. Conclusion: These findings clearly suggest the protective role of alcoholic leaf extract of M. indica against oxidative stress induced by DOX. PMID:28894627

Electrocardiographic Presentation, Cardiac Arrhythmias, and Their Management in β-Thalassemia Major Patients.

PubMed

Russo, Vincenzo; Rago, Anna; Papa, Andrea Antonio; Nigro, Gerardo

2016-07-01

Beta-thalassemia major (β-TM) is a genetic hemoglobin disorder characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Clinical management of thalassemia major consists in regular long-life red blood cell transfusions and iron chelation therapy to remove iron introduced in excess with transfusions. Iron deposition in combination with inflammatory and immunogenic factors is involved in the pathophysiology of cardiac dysfunction in these patients. Heart failure and arrhythmias, caused by myocardial siderosis, are the most important life-limiting complications of iron overload in beta-thalassemia patients. Cardiac complications are responsible for 71% of global death in the beta-thalassemia major patients. The aim of this review was to describe the most frequent electrocardiographic abnormalities and arrhythmias observed in β-TM patients, analyzing their prognostic impact and current treatment strategies. © 2016 Wiley Periodicals, Inc.

Hyperkalemia masked by pseudo-stemi infarct pattern and cardiac arrest.

PubMed

Peerbhai, Shareez; Masha, Luke; DaSilva-DeAbreu, Adrian; Dhoble, Abhijeet

2017-12-01

Hyperkalemia is a common electrolyte abnormality and has well-recognized early electrocardiographic manifestations including PR prolongation and symmetric T wave peaking. With severe increase in serum potassium, dysrhythmias and atrioventricular and bundle branch blocks can be seen on electrocardiogram. Although cardiac arrest is a worrisome consequence of untreated hyperkalemia, rarely does hyperkalemia electrocardiographically manifest as acute ischemia. We present a case of acute renal failure complicated by malignant hyperkalemia and eventual ventricular fibrillation cardiac arrest. Recognition of this disorder was delayed secondary to an initial ECG pattern suggesting an acute ST segment elevation myocardial infarction (STEMI). Emergent coronary angiography performed showed no evidence of coronary artery disease. Pseudo-STEMI patterns are rarely seen in association with acute hyperkalemia and are most commonly described with patient without acute cardiac symptomatology. This is the first such case presenting concurrently with cardiac arrest. A brief review of this rare pseudo-infarct pattern is also given.

Telefetalcare: a first prototype of a wearable fetal electrocardiograph.

PubMed

Fanelli, A; Signorini, M G; Ferrario, M; Perego, P; Piccini, L; Andreoni, G; Magenes, G

2011-01-01

Fetal heart rate monitoring is fundamental to infer information about fetal health state during pregnancy. The cardiotocography (CTG) is the most common antepartum monitoring technique. Abdominal ECG recording represents the most valuable alternative to cardiotocography, as it allows passive, non invasive and long term fetal monitoring. Unluckily fetal ECG has low SNR and needs to be extracted from abdominal recordings using ad hoc algorithms. This work describes a prototype of a wearable fetal ECG electrocardiograph. The system has flat band frequency response between 1-60 Hz and guarantees good signal quality. It was tested on pregnant women between the 30(th) and 34(th) gestational week. Several electrodes configurations were tested, in order to identify the best solution. Implementation of a simple algorithm for FECG extraction permitted the reliable detection of maternal and fetal QRS complexes. The system will allow continuative and deep screening of fetal heart rate, introducing the possibility of home fetal monitoring.

Therapeutic trial of granulocyte-colony stimulating factor for dilated cardiomyopathy in three dogs.

PubMed

Park, Chul; Yoo, Jong-Hyun; Jeon, Hyo-Won; Kang, Byeong-Teck; Kim, Jung-Hyun; Jung, Dong-In; Lim, Chae-Young; Lee, Hye-Jung; Hahm, Dae-Hyun; Woo, Eung-Je; Park, Hee-Myung

2007-09-01

Three dogs were presented to us for evaluation of cardiac problems. Electrocardiographic recordings revealed severe tachyarrhythmia and atrial fibrillation with ventricular tachycardia in 2 of the 3 dogs. The echocardiographic findings of the 3 dogs revealed markedly decreased fractional shortening and a marked increase in E-point septal separation. Based on the results of electrocardiographic and echocardiographic evaluation, the 3 dogs were diagnosed as dilated cardiomyopathy (DCM). The dogs were treated with conventional cardiac medication, but cardiac function did not improve and the clinical signs remained. We subsequently attempted treatment with granulocyte-colony stimulating factor (G-CSF; 10 microg/kg, subcutaneously). The specific purpose of G-CSF therapy for DCM was to improve cardiac function and a significant improvement in cardiac function was confirmed. The three dogs had no treatment side effects. This case report suggests that G-CSF might have therapeutic effects for medically refractory DCM in dogs.

Electrocardiographic screening for emphysema: the frontal plane P axis.

PubMed

Baljepally, R; Spodick, D H

1999-03-01

Because the most characteristic and sensitive electrocardiographic (ECG) correlate of pulmonary emphysema in adults is verticalization of the frontal plane P-wave vector (P axis), we investigated its strength as a lone criterion to screen for obstructive pulmonary disease (OPD) in an adult hospital population. In all, 954 consecutive unselected ECGs were required to yield 100 with P axis > or = +70 degrees (unequivocally negative P in a VL during sinus rhythm) and pulmonary function tests. and 100 with P axis < or = +50 degrees (unequivocally positive P-aVL). Obstructive pulmonary disease by both pulmonary function test and clinical criteria was present in 89 of 100 patients with vertical P axes and 4 of 100 patients without OPD. The high sensitivity (89% for this series) and high specificity (96%) makes vertical P axis a useful screening criterion. Its at-a-glance simplicity makes it "user-friendly."

[Medical technology: the leading trend in the conversion of an enterprise].

PubMed

Grodetskiĭ, V P; Kuznetsov, V I

1996-01-01

The Izhevsky motozavod (Aksion Public stock company) is one of the Russia's largest production associations (PA), which manufactures a wide range of products for various purposes, including those for implementation of space programmes. Medical engineering is close to space instrument making as it required special technologies, high quality and reliability for its manufacture. The development and introduction of medical equipment into production of the Izhevsky motozavod PA are under way along several basic lines: electrocardiographic equipment and defibrillators, devices for maternity and child care, ambulances, reanimobiles, etc. The most interesting produce, such as one-channel EK1 TTSSP-01 (for emergency care) and EK1T-04 electrocardiographs, DKI-H-04 defibrillator, Oksipuls-01 pulsoximeter, a DLTB-01 unit for diagnosis and treatment of tubal sterility in females, a KPH-01 unit for neonatal resuscitation, an ambulance, a Nadezhda reanimobile, etc. are briefly described.

Noninvasive ergonovine maleate provocative testing for coronary artery spasm: the need for routine thallium-201 imaging

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

Shanes, J.G.; Krone, R.J.; Fisher, K.

1983-01-01

We administered ergonovine and used both electrocardiographic monitoring and thallium-/sup 201/ (/sup 201/Tl) imaging to detect reversible ischemia in 100 patients. Patients already established as having coronary artery spasm and those with nonbypassed, proximal, high-grade coronary artery stenosis were excluded. No complication occurred in any patient. The use of thallium imaging in addition to electrocardiographic monitoring resulted in a higher degree of sensitivity than did ECG monitoring alone. Fourteen patients demonstrated evidence of coronary artery spasm as documented by /sup 201/Tl imaging but of the 14, significant ECG changes occurred in only 50%, and classic ST segment elevation in 21%.more » Thus, in carefully selected patients the noninvasive provocation of coronary spasm can be accomplished safely, but ECG monitoring must be combined with thallium-/sup 201/ imaging to achieve an acceptable degree of sensitivity.« less

Life-threatening heat stroke presenting with ST elevations: a report of consecutive cases during the heat wave in Austria in July 2013.

PubMed

Lassnig, Elisabeth; Dinkhauser, Patrick; Maurer, Edwin; Eber, Bernd

2014-08-01

Heat stroke is a life-threatening condition due to an acute thermoregulatory failure during exposure to high environmental temperatures. We report a series of four cases (three exertional, one classic heat stroke) during the heat wave of July 2013 in Austria. All of them presented with a core temperature > 41 °C, central nervous dysfunction, acute respiratory and renal failure, disseminated intravascular coagulation, rhabdomyolysis, and severe electrocardiographic changes, two cases even mimicking ST-elevation myocardial infarction. The patients were cooled to normal temperature with the "Arctic sun" external cooling system within hours. Electrocardiographic changes resolved quickly. All patients primarily recovered from multiple organ dysfunction and could be discharged from intensive care unit. Unfortunately, the two elder patients died 1 week and 5 weeks later because of late complications.

Electrocardiographic findings in athletes: the prevalence of left ventricular hypertrophy and conduction defects.

PubMed

Langdeau, J B; Blier, L; Turcotte, H; O'Hara, G; Boulet, L P

2001-06-01

To determine whether there are electrocardiographic differences or distinctive abnormalities between athletes and sedentary subjects, and to verify the relationship between vagal activity measured by heart rate variability (SD of all normal-to-normal intervals [SDNN]) and possible electrocardiographic abnormalities. Resting electrocardiograms and heart rate variability measurements were performed separately during a single visit on 100 athletes and 50 nonathlete control subjects aged 18 to 55 years. The athletes were from the following various sports disciplines: long-distance running, mountain biking, cross-country skiing, biathlon, speed skating, swimming and triathlon. There were significantly longer RR intervals, PR intervals and QT intervals in athletes than in control subjects (all P<0.05). The QRS complex and QTc did not show significant differences (both P>0.05). The prevalence of left ventricular hypertrophy (LVH) and incomplete right bundle branch block (IRBBB) was 10% and 7%, respectively, in athletes, but these conditions were absent in control subjects; among athletes, 2% presented with both conditions. LVH and IRBBB were more common among long-distance runners (six of 14 and four of 14, respectively) and could be attributed to normal, long term adaptation to intense, repeated exercise. LVH was related to age (P=0.04), whereas IRBBB was influenced by the number of years of training in the respective sports discipline (P=0.03). The mean SDNN value was significantly more elevated in athletes (P=0.0001), reflecting a higher parasympathetic tone than in sedentary control subjects. However, there was no relationship between vagal activity and LVH or IRBBB (both P>0.05).

Hormonal, Electrolytic, and Electrocardiographic Evaluations in Bitches With Eutocia and Dystocia.

PubMed

Simões, Carla Regina Barbieri; Vassalo, Flávia Gardilin; Lourenço, Maria Lúcia Gomes; de Souza, Fabiana Ferreira; Oba, Eunice; Sudano, Mateus José; Prestes, Nereu Carlos

2016-12-01

The objective of the study was to assess clinical alterations, electrocardiographic, hematological, biochemical, hemogasometric, electrolytic, and hormone plasma concentrations in bitches with eutocia and dystocia. Overall, 28 bitches (dystocia, n = 22 and eutocia, n = 6) were assessed. The evaluations were performed at 2 time points, M1 (1 hour prepartum-eutocia group and cesarean or clinical intervention-dystocia group) and M2 (postpartum-eutocia or dystocia group and anesthetic recovery-dystocia group). The main clinical finding was the hypothermia (mean: 36.9°C dystocia vs. 36.8°C eutocia). Sinus arrhythmia and tachycardia were the electrocardiographic parameters predominant in eutocia and sinus rhythm in dystocia group. The P wave amplitude, heart rate, creatinine concentration, hematocrit, and hemoglobin were increased in M1 (P < .05), whereas the concentration of TCO 2 was higher in M2. There was an increase in P 4 concentration in dystocia and total T 3 concentrations were increased in M1 in both groups. Total T 4 was higher in dystocia during M1 and in dystocia during M2 in eutocia than in dystocia. We concluded that at 1 hour prepartum or pre-cesarean, there is an increase in heart rate in bitches with eutocia or dystocia, and this finding was correlated to thyroid hormone concentration. P 4 concentrations remained high during dystocia, and hematological and biochemical changes returned to normal after parturition. The evaluation of these parameters in pregnancy can be used as tool to prevent dystocia and consequent fetal death. Copyright © 2016 Elsevier Inc. All rights reserved.

Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association.

PubMed

Sandau, Kristin E; Funk, Marjorie; Auerbach, Andrew; Barsness, Gregory W; Blum, Kay; Cvach, Maria; Lampert, Rachel; May, Jeanine L; McDaniel, George M; Perez, Marco V; Sendelbach, Sue; Sommargren, Claire E; Wang, Paul J

2017-11-07

This scientific statement provides an interprofessional, comprehensive review of evidence and recommendations for indications, duration, and implementation of continuous electro cardiographic monitoring of hospitalized patients. Since the original practice standards were published in 2004, new issues have emerged that need to be addressed: overuse of arrhythmia monitoring among a variety of patient populations, appropriate use of ischemia and QT-interval monitoring among select populations, alarm management, and documentation in electronic health records. Authors were commissioned by the American Heart Association and included experts from general cardiology, electrophysiology (adult and pediatric), and interventional cardiology, as well as a hospitalist and experts in alarm management. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Authors were assigned topics relevant to their areas of expertise, reviewed the literature with an emphasis on publications since the prior practice standards, and drafted recommendations on indications and duration for electrocardiographic monitoring in accordance with the American Heart Association Level of Evidence grading algorithm that was in place at the time of commissioning. The comprehensive document is grouped into 5 sections: (1) Overview of Arrhythmia, Ischemia, and QTc Monitoring; (2) Recommendations for Indication and Duration of Electrocardiographic Monitoring presented by patient population; (3) Organizational Aspects: Alarm Management, Education of Staff, and Documentation; (4) Implementation of Practice Standards; and (5) Call for Research. Many of the recommendations are based on limited data, so authors conclude with specific questions for further research. © 2017 American Heart Association, Inc.

Automated measurements for individualized heart rate correction of the QT interval.

PubMed

Mason, Jay W; Moon, Thomas E

2015-04-01

Subject-specific electrocardiographic QT interval correction for heart rate is often used in clinical trials with frequent electrocardiographic recordings. However, in these studies relatively few 10-s, 12-lead electrocardiograms may be available for calculating the individual correction. Highly automated QT and RR measurement tools have made it practical to measure electrocardiographic intervals on large volumes of continuous electrocardiogram data. The purpose of this study was to determine whether an automated method can be used in lieu of a manual method. In 49 subjects who completed all treatments in a four-armed crossover study we compared two methods for derivation of individualized rate-correction coefficients: manual measurement on 10-s electrocardiograms and automated measurement of QT and RR during continuous 24-h electrocardiogram recordings. The four treatments, received by each subject in a latin-square randomization sequence were placebo, moxifloxacin, and two doses of an investigational drug. Analysis of continuous electrocardiogram data yielded a lower standard deviation of QT:RR regression values than the manual method, though the differences were not statistically significant. The within-subject and within-treatment coefficients of variation between the manual and automated methods were not significantly different. Corrected QT values from the two methods had similar rates of true and false positive identification of moxifloxacin's QT prolonging effect. An automated method for individualized rate correction applied to continuous electrocardiogram data could be advantageous in clinical trials, as the automated method is simpler, is based upon a much larger volume of data, yields similar results, and requires no human over-reading of the measurements. © The Author(s) 2015.

A structured reading algorithm improves telemetric detection of atrial fibrillation after acute ischemic stroke.

PubMed

Kallmünzer, Bernd; Breuer, Lorenz; Hering, Christiane; Raaz-Schrauder, Dorette; Kollmar, Rainer; Huttner, Hagen B; Schwab, Stefan; Köhrmann, Martin

2012-04-01

Anticoagulation is a highly effective secondary prevention in patients with cardioembolic stroke and atrial fibrillation/flutter (AF). However, the condition remains underdiagnosed, because paroxysmal AF may be missed by diagnostic tests in the acute phase. In this study, the sensitivity of AF detection was assessed for serial electrocardiographic recordings and continuous stroke unit telemetric monitoring with or without a structured algorithm to analyze telemetric data (SEA-AF). Three hundred forty-six consecutive patients with acute ischemic stroke were prospectively included and subjected to standard telemetric monitoring. In addition, telemetric data were separately analyzed following SEA-AF, consisting of a structured evaluation of episodes with high risk for AF and a chronological beat-to-beat screening of the full registration. Serial electrocardiograms were conducted in 24-hour intervals. Median effective telemetry monitoring time was 75.5 hours (interquartile range 64-86 hours). Overall, AF was diagnosed in 119 of 346 patients (34.4%). The structured reading algorithm was the most sensitive method to detected AF. Conventional telemetry and serial electrocardiographic assessments were less effective. However, only 35% of patients with previously documented paroxysmal AF and negative baseline electrocardiogram demonstrated AF episodes during monitoring. Continuous stroke unit telemetry using SEA-AF shows a significantly higher detection rate for AF compared with daily electrocardiographic assessments and standard telemetry without structured reading. The low overall probability to detect paroxysmal AF with either method during the first days after stroke demonstrates the urgent need for complementary diagnostic strategies such as long-term monitoring and frequent follow-up assessments. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT01177748.

Association of functional genetic variants of A-kinase anchoring protein 10 with QT interval length in full-term Polish newborns.

PubMed

Łoniewska, Beata; Kaczmarczyk, Mariusz; Clark, Jeremy Simon; Gorący, Iwona; Horodnicka-Józwa, Anita; Ciechanowicz, Andrzej

2015-03-16

A-Kinase Anchoring Proteins (AKAPs) coordinate the specificity of protein kinase A signaling by localizing the kinase to subcellular sites. The 1936G (V646) AKAP10 allele has been associated in adults with low cholinergic/vagus nerve sensitivity, shortened PR intervals in ECG recording and in newborns with increased blood pressure and higher cholesterol cord blood concentration. The aim of the study was to answer the question of whether 1936A > G AKAP10 polymorphism is associated with the newborn electrocardiographic variables. Electrocardiograms were recorded from 114 consecutive healthy Polish newborns (55 females, 59 males), born after 37 gestational weeks to healthy women with uncomplicated pregnancies. All recordings were made between 3(rd) and 7(th) day of life to avoid QT variability. The heart rate per minute and duration of PR, QRS, RR and QT intervals were usually measured. The ECGs were evaluated independently by three observers. At birth, cord blood of neonates was obtained for isolation of genomic DNA. The distribution of anthropometric and electrocardiographic variables in our cohort approached normality (skewness < 2 for all variables). No significant differences in anthropometric variables and electrocardiographic traits with respect to AKAP10 genotype were found. Multiple regression analysis with adjustment for gender, gestational age and birth mass revealed that QTc interval in GG AKAP10 homozygotes was significantly longer, but in range, when compared with A alleles carriers (AA + AG, recessive mode of inheritance). No rhythm disturbances were observed. Results demonstrate possible association between AKAP10 1936A > G variant and QTc interval in Polish newborns.

Electrocardiographic parameters of captive lions (Panthera leo) and tigers (Panthera tigris) immobilized with ketamine plus xylazine.

PubMed

Larsson, Maria Helena M A; Coelho, Fernanda M; Oliveira, Valéria M C; Yamaki, Fernanda L; Pereira, Guilherme G; Soares, Elaine C; Fedullo, José Daniel L; Pereira, Roberto C; Ito, F H

2008-09-01

Twenty-seven healthy captive lions (Panthera leo) and 13 healthy captive tigers (Panthera tigris) from São Paulo Zoo (Fundação Parque Zoológico de Sã Paulo, São Paulo, Brazil) collection were selected for this study. They were anesthetized with ketamine (10 mg/kg) combined with xylazine (1-2 mg/kg) for physical examinations, hematologic and serum chemical analysis and electrocardiogram recording. The main aim of this research was to gather initial information about normal electrocardiographic parameters of large felids. Standard P-QRS-T deflections on leads described for domestic carnivores were analyzed, and they did not greatly differ from those of large felids, taking into account the greater weight and corporal mass of large felids. Heart rate of lions ranged from 42 to 76 beats per minute (bpm). Heart rate of tigers ranged from 56 to 97 bpm. In both species, the most common rhythm detected was normal sinus rhythm followed by sinus arrhythmia; wandering pacemaker was also observed with normal sinus rhythm or sinus arrhythmia. Mean electrical axis lay between +60 degrees and +120 degrees. QRS complexes were predominantly positive in leads DI, DII, DIII, and AVF, and negative in AVR and AVL. This study provides insights into normal electrocardiograms of large felids. Wider investigations on the same subject are necessary to establish criteria for the recognition of abnormalities in these species and should include other anesthetic drug(s) combinations and reports of electrocardiographic features of animals with cardiac disease and electrolytes disturbances.

The electrocardiographic manifestations of athlete's heart and their association with exercise exposure.

PubMed

Bessem, Bram; De Bruijn, Matthijs C; Nieuwland, Wybe; Zwerver, Johannes; Van Den Berg, Maarten

2018-05-01

The aim of this study was to define the minimum amount of exercise per week ('current exposure') and the total amount of exercise ('lifetime exposure') needed to lead to the electrocardiographic changes fitting athlete's heart. All the pre-participation screenings (including electrocardiograms (ECGs)) from collegiate athletes performed at University Sports Medical Center in 2013 and 2014 were collected. Data on height, weight, sex, age, current sport(s) participation and lifetime sport(s) participation were collected. Current exposure was categorised into 0-3, 3-6, 6-10 and >10 hours/week. Lifetime sport exposure was divided into five categories: 0-1000, 1001-2000, 2001-3000, 3001-4000 and >4000 hours. The study population consisted of 1229 athletes (current exposure) and 1104 athletes (lifetime exposure). Current sport exposure: There was a significant increase in training-related ECG changes in the category 3-6 vs. <3 hours/week. When looking at individual parameters, we found an association with a significant difference in sinus bradycardia and QRS voltage (<3 vs. 3-6 hours/week) and first-degree AV-block (<3 vs. >10 hours/week).Lifetime sport exposure: There was an increase in training-related ECG changes that reached significance at an exposure >3000 hours. When looking at individual parameters, we found an association with a significant difference in sinus bradycardia (0-1000 vs. 2001-3000), QRS voltage (0-1000 vs. 3001-4000) and first-degree AV-block (0-1000 vs. >4000). A minimum of ≥3 hours/week of current exposure and a lifetime exposure of >3000 hours is needed to lead to the electrocardiographic changes fitting athlete's heart.

Some Experiments with Biological Applications for the Elementary Laboratory

ERIC Educational Resources Information Center

Kammer, D. W.; Williams, J. A.

1975-01-01

Summarizes physics laboratory experiments with applications in the biological sciences. Includes the following topics: mechanics of the human arm, fluid flow in tubes, physics of learning, the electrocardiograph, nerve impulse conduction, and corrective lenses for eye defects. (Author/MLH)

Cellular mechanisms underlying the effects of milrinone and cilostazol to suppress arrhythmogenesis associated with Brugada syndrome.

PubMed

Szél, Tamás; Koncz, István; Antzelevitch, Charles

2013-11-01

Brugada syndrome is an inherited disease associated with vulnerability to ventricular tachycardia and sudden cardiac death in young adults. Milrinone and cilostazol, oral phosphodiesterase (PDE) type III inhibitors, have been shown to increase L-type calcium channel current (ICa) and modestly increase heart rate by elevating the level of intracellular cyclic adenosine monophosphate. To examine the effectiveness of these PDE inhibitors to suppress arrhythmogenesis in an experimental model of Brugada syndrome. Action potential (AP) and electrocardiographic recordings were obtained from epicardial and endocardial sites of coronary-perfused canine right ventricular wedge preparations. The Ito agonist NS5806 (5 μM) and Ca(2+) channel blocker verapamil (2 μM) were used to pharmacologically mimic Brugada phenotype. The combination induced all-or-none repolarization at some epicardial sites but not others, leading to ST-segment elevation as well as an increase in both epicardial and transmural dispersion of repolarization. Under these conditions, phase 2 reentry developed as the epicardial AP dome propagated from sites where it was maintained to sites at which it was lost, generating closely coupled extrasystoles and ventricular tachycardia. The addition of the PDE inhibitor milrinone (2.5 μM) or cilostazol (5-10 μM) to the coronary perfusate restored the epicardial AP dome, reduced dispersion, and abolished phase 2 reentry-induced extrasystoles and ventricular tachycardia. Our study identifies milrinone as a more potent alternative to cilostazol for reversing the repolarization defects responsible for the electrocardiographic and arrhythmic manifestations of Brugada syndrome. Both drugs normalize ST-segment elevation and suppress arrhythmogenesis in experimental models of Brugada syndrome. © 2013 Heart Rhythm Society. All rights reserved.

Detection of heart rate and rhythm with a smartphone-based electrocardiograph versus a reference standard electrocardiograph in dogs and cats.

PubMed

Kraus, Marc S; Gelzer, Anna R; Rishniw, Mark

2016-07-15

OBJECTIVE To evaluate the diagnostic utility of ECGs acquired with a smartphone-based device, compared with reference 6-lead ECGs, for identification of heart rate and rhythm in dogs and cats. DESIGN Prospective study. ANIMALS 51 client-owned dogs and 27 client-owned cats. PROCEDURES Patients examined by a small animal referral cardiology service between April 2012 and January 2013 were enrolled consecutively. In each patient, a 30-second ECG was simultaneously acquired with a smartphone-based device (a bipolar, single-lead recorder coupled to a smartphone with an ECG application) and a standard 6-lead ECG machine. Recordings were evaluated by 3 board-certified cardiologists, and intra- and interobserver agreement were evaluated for both rhythm diagnosis and QRS polarity identification. RESULTS Values for instantaneous and mean heart rates for the smartphone-acquired and reference ECGs were within 1 beat of each other when mean heart rates were calculated. Intraobserver agreement for rhythm assessment was very high, with maximum disagreement for any observer for only 2 of 51 dogs and only 4 of 27 cats. There was minimal disagreement in the polarity of depolarization between the smartphone-acquired and reference ECGs in dogs but frequent disagreement in cats. Interobserver agreement for smartphone-acquired ECGs was similar to that for reference ECGs. with all 3 observers agreeing on the rhythm analysis and minimal disagreement on polarity. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ECGs acquired with the smartphone-based device accurately identified heart rate and rhythm in dogs and cats. Thus, the device may allow veterinarians to evaluate and manage cardiac arrhythmias relatively inexpensively at the cage side and could also allow clinicians to rapidly share information via email for further consultation, potentially enhancing patient care.

Influence of Zoledronic Acid on Atrial Electrophysiological Parameters and Electrocardiographic Measurements.

PubMed

Tisdale, James E; Allen, Matthew R; Overholser, Brian R; Jaynes, Heather A; Kovacs, Richard J

2015-06-01

Our objective was to determine effects of zoledronic acid (ZA) on atrial electrophysiological parameters and electrocardiographic measurements. Ex vivo perfusion study: Isolated guinea pig hearts were perfused with modified Krebs-Henseleit (K-H) buffer with or without ZA 0.07 mg/kg/L (each n = 6). In ZA-perfused hearts, atrial action potential at 90% repolarization (APD90 ) decreased more from baseline than in controls (-23.2% ± -5.1% vs. -2.1% ± -8.1%, P < 0 .0001), as did APD30 (-28.8% ± -3.8% vs. -2.1% ± -2.1%, P < 0.0001). In vivo dose-response study: Guinea pigs underwent intraperitoneal injections every 2 weeks in 1 of 4 groups (each n = 8): ZA 0.007 mg/kg (low-dose), ZA 0.07 mg/kg (medium-dose), ZA 0.7 mg/kg (high-dose), or placebo. Hearts were excised at 8 weeks and perfused with modified K-H. Atrial effective refractory period (ERP) was lower with medium- and high-dose ZA versus placebo (P = 0.004). Atrial APD30 was lower with high-dose ZA versus placebo, low and medium doses (P < 0.001). Canine ECG study: Mature female beagles received intravenous ZA 0.067 mg/kg or saline (placebo; each n = 6) every 2 weeks for 12 weeks. P wave dispersion was greater in the ZA group (7.7 ± 3.7 vs. 3.4 ± 2.6 ms, P = 0.04). There were no significant differences in P wave index, maximum or minimum P wave duration, or PR interval. ZA shortens left atrial APD and ERP and increases P wave dispersion. © 2015 Wiley Periodicals, Inc.

Red Ginseng (Panax ginseng) Decreases Isoproterenol-Induced Cardiac Injury via Antioxidant Properties in Porcine

PubMed Central

Lim, Kyu Hee; Cho, Jae Youl; Kim, Bumseok; Bae, Bong-Seuk

2014-01-01

Abstract Red ginseng (RG, Panax ginseng) has been shown to possess various ginsenosides. These ginsenosides are widely used for treating cardiovascular diseases in Asian communities. The present study was designed to evaluate the cardioprotective potential of RG against isoproterenol (ISO)-induced myocardial infarction (MI), by assessing electrocardiographic, hemodynamic, and biochemical parameters. Male porcines were orally administered with RG (250 and 500 mg/kg) or with vehicle for 9 days, with concurrent intraperitoneal injections of ISO (20 mg/kg) on the 8th and 9th day. RG significantly attenuated ISO-induced cardiac dysfunctions as evidenced by improved ventricular hemodynamic functions and reduced ST segment and QRS complex intervals. Also, RG significantly ameliorated myocardial injury parameters such as antioxidants. Malonaldialdehyde formation was also inhibited by RG. Based on the results, it is concluded that RG possesses significant cardioprotective potential through the inhibition of oxidative stress and may serve as an adjunct in the treatment and prophylaxis of MI. PMID:24456361

A description of nurses' decision-making in managing electrocardiographic monitor alarms.

PubMed

Gazarian, Priscilla K; Carrier, Natalie; Cohen, Rachel; Schram, Haley; Shiromani, Samara

2015-01-01

To describe the cues and factors that nurses use in their decision-making when responding to clinical alarms. Alarms are designed to be very sensitive, and as a result, they are not very specific. Lack of adherence to the practice standards for electrocardiographic monitoring in hospital settings has been observed, resulting in overuse of the electrocardiographic monitoring. Monitoring without consideration of clinical indicators uses scarce healthcare resources and may even produce untoward circumstances because of alarm fatigue. With so many false alarms, alarm fatigue represents a symptom of a larger problem. It cannot be fixed until all of the factors that contribute to its existence have been examined. This was a qualitative descriptive study. This study was conducted at an academic medical centre located in the Northeast United States. Eight participants were enrolled using purposive sampling. Nurses were observed for two three-hour periods. Following each observation, the nurse was interviewed using the critical decision method to describe the cognitive processes related to the alarm activities. Qualitative data from the conducted interviews were analysed via an a priori framework founded in the critical decision method. This study reveals information, experience, guidance and decision-making as the four prominent categories contributing to nurses' decision-making in relation to alarm management. Managing technology was a category not identified a priori that emerged in the data analysis. Nurses revealed a breadth of information needed to adequately identify and interpret monitor alarms, and how they used that information to put the alarms into the particular context of an individual patient's situations. Understanding the cues and factors nurses use when responding to cardiac alarms will guide the development of learning experiences and inform policies to guide practice. © 2014 John Wiley & Sons Ltd.

Electrocardiographic findings in chronic hemodialysis patients.

PubMed

Bignotto, Luís Henrique; Kallás, Marina Esteves; Djouki, Rafael Jorge Teixeira; Sassaki, Marcela Mayume; Voss, Guilherme Ota; Soto, Cristina Lopez; Frattini, Fernando; Medeiros, Flávia Silva Reis

2012-01-01

Cardiovascular disease is the leading cause of mortality among patients on dialysis. When considering all causes of death, about 30% are classified as cardiac arrest, death of unknown cause or cardiac arrhythmia. The increasing time of ventricular depolarization and repolarization, measured non-invasively by measuring the QT interval on the electrocardiogram at rest, has emerged as a predictor of complex ventricular arrhythmias, a major cause of sudden cardiac death. To determine the electrocardiographic alterations present in hemodialysis (HD) patients, measuring the QT interval and its relationship with clinical and laboratory variables. Patients above 18 years on dialysis were approached to participate in the study and, after consent, were submitted to the examination of 12-lead electrocardiogram. Clinical data were reviewed to assess the presence of comorbidities, as well as anthropometric and blood pressure measures. Blood samples were collected to determinate hemoglobin and serum levels of calcium, phosphorus and potassium. One hundred and seventy nine patients were included in the study. The majority of the patients were male (64.8%) and white (54.7%); the average age was 58.5 ± 14.7 years old. About 50% of all patients had, at least, one electrical conduction disturb. About 50% of all patients had QTc prolongation and experienced a significant increase in the frequency of Left Ventricular Hypertrophy (LVH), changes of the cardiac rhythm and bundle branch blocks, and a lower body mass index (BMI), when compared with normal QTc interval patients. Patients with chronic kidney disease (CKD) on hemodialysis had high frequency of abnormal electrocardiographic findings, including a high prevalence of patients with prolonged QTc interval. This study also found a significant association between prolonged QTc interval and the presence of Diabetes and lower values of BMI.

Value of normal electrocardiographic findings in predicting resting left ventricular function in patients with chest pain and suspected coronary artery disease

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

O'Keefe, J.H. Jr.; Zinsmeister, A.R.; Gibbons, R.J.

1989-06-01

Characterization of left ventricular function is important in managing patients with coronary artery disease. Although many methods are available to assess left ventricular function, most are either expensive, invasive, or both. In this study, we examined the ability of normal or near-normal resting electrocardiographic findings to predict resting left ventricular ejection fraction, measured by resting radionuclide angiography, in 874 patients with chest pain and suspected coronary artery disease. A retrospective review was undertaken of 4,410 Mayo Clinic patients who underwent rest and exercise radionuclide ventriculography for the evaluation of chest pain and known or suspected coronary artery disease; of these,more » 874 patients met the inclusion criteria for the current study. A 15-lead electrocardiogram, which was interpreted by the cardiologist or cardiology trainee working in the laboratory, was obtained at the same evaluation as the radionuclide study. In 590 patients with no previous history of a myocardial infarction and entirely normal resting electrocardiographic results without nonspecific ST-T wave abnormalities, the mean left ventricular ejection fraction was 0.63 +/- 0.004, and 559 patients (95%) had a normal resting ejection fraction (defined as 0.50 or more). Both nonspecific ST-T wave abnormalities (p less than 0.001) and, to a lesser degree, a history of myocardial infarction (p = 0.06) were independent predictors of an abnormal resting ejection fraction. In 185 patients with nonspecific ST-T wave abnormalities and no history of myocardial infarction, the mean left ventricular ejection fraction was 0.61 +/- 0.009, and 85% had a normal resting ejection fraction.« less

LONG-TERM EFFECTS OF CHLORTHALIDONE VS HYDROCHLOROTHIAZIDE ON ELECTROCARDIOGRAPHIC LEFT VENTRICULAR HYPERTROPHY IN THE MULTIPLE RISK FACTOR INTERVENTION TRIAL

PubMed Central

Ernst, Michael E.; Neaton, James D.; Grimm, Richard H.; Collins, Gary; Thomas, William; Soliman, Elsayed Z.; Prineas, Ronald J.

2011-01-01

Chlorthalidone (CTD) reduces 24-hour blood pressure more effectively than hydrochlorothiazide (HCTZ), but whether this influences electrocardiographic left ventricular hypertrophy (LVH) is uncertain. One source of comparative data is the Multiple Risk Factor Intervention Trial (MRFIT), which randomly assigned 8,012 hypertensive men to special intervention (SI) or usual care (UC). SI participants could use CTD or HCTZ initially; previous analyses have grouped clinics by their main diuretic used (C-clinics: CTD; H-clinics: HCTZ). After 48 months, SI participants receiving HCTZ were recommended to switch to CTD, in part, because higher mortality was observed for SI compared to UC participants in H-clinics, while the opposite was found in C-clinics. In this analysis, we examined change in continuous measures of electrocardiographic LVH using both an ecologic analysis by previously-reported C- or H-clinic groupings, and an individual participant analysis where use of CTD or HCTZ by SI participants was considered and updated annually. Through 48 months, differences between SI and UC in LVH were larger for C-clinics compared to H-clinics (Sokolow-Lyon: −93.9 vs −54.9 μV, P=0.049; Cornell voltage: −68.1 vs −35.9 μV, P=0.019; Cornell voltage product: −4.6 vs −2.2 μV/ms, P=0.071; left ventricular mass: −4.4 vs −2.8 gm, P=0.002). At the individual participant level, Sokolow-Lyon and left ventricular mass were significantly lower for SI men receiving CTD compared to HCTZ through 48 months and 84 months of follow-up. Our findings on LVH support the idea that greater blood pressure reduction with CTD than HCTZ may have led to differences in mortality observed in MRFIT. PMID:22025372

Acute and chronic management in patients with Brugada syndrome associated with electrical storm of ventricular fibrillation.

PubMed

Ohgo, Takeshi; Okamura, Hideo; Noda, Takashi; Satomi, Kazuhiro; Suyama, Kazuhiro; Kurita, Takashi; Aihara, Naohiko; Kamakura, Shiro; Ohe, Tohru; Shimizu, Wataru

2007-06-01

Some patients with Brugada syndrome experience an electrical storm of ventricular fibrillation (VF). The purpose of this study was to investigate the clinical, laboratory, electrocardiographic, and electrophysiologic characteristics, acute and subsequent chronic treatment, and follow-up data of patients with Brugada syndrome associated with electrical storm of VF. Sixty-seven patients with Brugada syndrome (65 men and 2 women, age 46 +/- 14 years) were divided into three groups: 7 patients with a history of electrical storm of VF (group I), 39 symptomatic patients with documented VF and/or syncope (group II), and 21 asymptomatic patients (group III). Electrical storm was defined as three or more episodes of VF per day recorded by the memory of an implantable cardioverter-defibrillator. No significant differences were observed among the three groups with regard to clinical (age at diagnosis, familial history of sudden cardiac death), laboratory (SCN5A mutation and serum potassium level), electrocardiographic and electrophysiologic characteristics, and follow-up duration after diagnosis. However, arrhythmic events during follow-up after diagnosis and number of arrhythmic events per patient were significantly higher in group I compared with groups II and III. Isoproterenol infusion (0.003 +/- 0.003 microg/kg/min for 24 +/- 13 days) completely suppressed electrical storm of VF in all five patients treated and was successfully replaced with oral medications, including denopamine, quinidine, isoproterenol, cilostazol, and bepridil alone or in combination. No specifically clinical, laboratory, electrocardiographic, and electrophysiologic characteristics were recognized in patients with Brugada syndrome associated with electrical storm of VF. Isoproterenol infusion was effective as an acute treatment in suppressing electrical storm of VF and was successfully replaced with chronic oral medications.

Longitudinal evaluation of P-wave dispersion and P-wave maximum in children after transcatheter device closure of secundum atrial septal defect.

PubMed

Grignani, Robert Teodoro; Tolentino, Kim Martin; Rajgor, Dimple Dayaram; Quek, Swee Chye

2015-06-01

Transcatheter device closure of the secundum atrial septal defect (ASD) in children prevents atrial arrhythmias in older age. However, the benefits of favourable atrial electrocardiographic markers in these children remain elusive. We aimed to review the electrocardiographic markers of atrial activity in a longitudinal fashion. We retrospectively reviewed longitudinal data of all children who underwent transcatheter device closure at the National University Hospital between 2004 and 2013. The inclusion criteria included the presence of a secundum-type ASD with left to right shunt and evidence of increased right ventricular volume load (Q p/Q s ratio >1.5 and/or right ventricular dilatation). A total of 25 patients with a mean follow-up of 44.7 ± 33.47 (7.3-117.4) months were included. P maximum and P dispersion decreased at 2 months, P amplitude at 1 week and remained so until last follow-up. A positive trend was seen with a correlation coefficient of +0.12 for P maximum, +0.08 for P dispersion and 0.34 for P amplitude. There was a higher baseline P amplitude and P dispersion in patients who were older than 10 years and a non-significant trend to support an increase in both P maximum (71.0 ± 8.8 vs. 73.2 ± 12.7), P dispersion (17.0 ± 6.5 vs. 22.0 ± 11.3) and P amplitude (0.88 ± 0.25 vs. 1.02 ± 0.23) in patients with an ASD more than 15 mm compared with an ASD <15 mm. There is reduction in both P maximum and P dispersion as early as 2 months, which persisted on follow-up. Earlier closure may result in more favourable electrocardiographic results.

Standardization of some electrocardiographic parameters of captive leopard cats (Leopardus tigrinus).

PubMed

Oda, Sam Goldy Shoyama; Yamato, Ronaldo Jun; Fedullo, José Daniel Luzes; Leomil Neto, Moacir; Larsson, Maria Helena Matiko Akao

2009-09-01

Thirty-three captive leopard cats, Leopardus tigrinus, were anesthetized with xylazine (1-2 mg/kg) and ketamine (10 mg/kg), and electrocardiograph (ECG) tests were recorded in all leads with 1 cm = 1 mV sensibility and 25 mm/sec speed repeating DII lead at 50 mm/sec speed with the same sensibility. Results expressed by mean and standard deviation were: heart rate (HR) = 107 +/- 17 (bpm); P-wave = 0.048 +/- 0.072 (s) x 0.128 +/- 0.048 (mV); PR interval = 0.101 +/- 0.081 (s); QRS compound = 0.053 +/- 0.012 (s) x 1.446 +/- 0.602 (mV); QT interval = 0.231 +/- 0.028 (s); R-wave (CV6LL) = 1.574 +/- 0.527 (mV); R-wave (CV6LU) = 1.583 +/- 0.818 (mV); heart rhythm: normal sinus rhythm (15.2%), sinus rhythm with wandering pacemaker (WPM) (60.6%), sinus arrhythmia with WPM (24.2%); electric axis: between +30 degrees and +60 degrees (6.1%), +60 (6.1%), between +60 degrees and +90 degrees (57.6%), +90 degrees (9%), between +90 degrees and +120 degrees (21.2%); ST segment: normal (75.7%), elevation (18.2%), depression (6.1%); T-wave polarity (DII): positive (100%); T-wave (V10): absent (6.1%), negative (63.6%), positive (18.2%), and with interference (12.1%). Through ECG data comparison with other species, unique features of Leopardus tigrinus' (leopard cat) ECG parameters were detected. Some of the study animals presented with an R-wave amplitude that was indicative of left ventricle overload according to patterns for normal domestic cats (Felis cati). Echocardiographic exams revealed normal heart cavities' function and morphology. The aim of this study was to establish some electrocardiographic parameters of captive L. tigrinus.

Effect of intravenous zoledronic acid infusion on electrocardiographic parameters in patients with osteoporosis.

PubMed

Aktas, I; Nazikoglu, C; Kepez, A; Ozkan, F U; Kaysin, M Y; Akpinar, P; Dogan, Z; Ileri, C; Saymaz, S; Erdogan, O

2016-12-01

We evaluated the effects of zoledronic acid (ZA) therapy on electrocardiographic (ECG) parameters for the first time in the literature. Measurements were performed on ECGs obtained before and after ZA infusion on the same day as well as 1 month after the infusion. ZA infusion did not have any short- or long-term effect on any parameter that might be associated with the tendency for atrial fibrillation or ventricular arrhythmias. The aim of the present study was to evaluate the early and late effects of ZA therapy on ECG parameters which might be associated with the tendency for atrial and ventricular arrhythmias. Consecutive patients with osteoporosis who were admitted to our clinic between December 2013 and December 2014 and who were scheduled to receive ZA infusion constituted our study population. Twelve-lead surface ECGs were obtained from all patients before and after ZA infusion on the same day as well as 1 month after the infusion. All ECG parameters were measured and compared with each other for each patient. Data of 100 patients were used in the analysis (9 male; 70.5 ± 11.6 years of age). There were no significant differences between repeated measurements regarding pmax, pmin, and p dispersion values. QT max and QT min values were significantly increased after infusion; however, there were no significant changes in QT dispersion, Tp-e interval, and Tp-e dispersion values. ZA infusion did not affect P wave dispersion both at the immediate post-infusion period and 1 month after infusion. QT values were significantly increased early after ZA infusion; however, there were no significant differences in parameters reflecting disparity of ventricular recovery times and transmural dispersion of ventricular repolarization. Based on these observations, it may be suggested that ZA infusion did not have any short- or long-term effect on any parameter that might be associated with the tendency for atrial fibrillation or ventricular arrhythmias.

Health Instruction Packages: Cardiac Anatomy.

ERIC Educational Resources Information Center

Phillips, Gwen; And Others

Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

Quick don-doff electrode pastes

NASA Technical Reports Server (NTRS)

Mosier, B.

1969-01-01

Evaluation of electrode pastes for use in electrocardiographs and electroencephalographs found that the one having the desired don-doff properties had to be water soluble or a water dispersible base. Poly /methyl vinyl ether/maleic anhydride/ or starch gels of the gum drop variety are two such bases.

Electrocardiograph Course.

ERIC Educational Resources Information Center

Kingston, Michael E.

1979-01-01

Instruction in electrocardiogram interpretation was provided for students at the University of Calgary by distributing complete cardiograms to them at the beginning of the week, for nine weeks, followed by analysis by an instructor at the end of the week. Skill development, reinforcement, course evaluation, and student satisfaction are described.

Electrocardiographic consequences of a peripatetic lifestyle in gray wolves (Canis lupus)

USGS Publications Warehouse

Constable, Peter; Hinchcliff, Ken; Demma, Nick; Callahan, Margaret; Dale, Bruce W.; Fox, Kevin; Adams, Layne G.; Wack, Ray; Kramer, Lynn

1998-01-01

Cardiac chamber enlargement and hypertrophy are normal physiologic responses to repetitive endurance exercise activity in human beings and domestic dogs. Whether similar changes occur in wild animals as a consequence of increased activity is unknown. We found that free-ranging gray wolves (Canis lupus, n=11), the archetypical endurance athlete, have electrocardiographic evidence of cardiac chamber enlargement and hypertrophy relative to sedentary captive gray wolves (n=20), as demonstrated by significant increases in QRS duration, QT interval, and QT interval corrected for heart rate, a tendency towards increased Q, R, and S wave voltages in all leads, and a significant decrease in heart rate. We conclude that exercise activity level and therefore lifestyle affects physiologic variables in wild animals. An immediate consequence of this finding is that physiologic measurements obtained from a captive wild-animal population with reduced exercise activity level may not accurately reflect the normal physiologic state for free-ranging members of the same species.

Frequency characteristics of the heart rate variability produced by Cheyne-Stokes respiration during 24-hr ambulatory electrocardiographic monitoring.

PubMed

Ichimaru, Y; Yanaga, T

1989-06-01

Spectral analysis of heart rates during 24-hr ambulatory electrocardiographic monitoring has been carried out to characterize the heart rate spectral components of Cheyne-Stokes respiration (CSR) by using fast Fourier transformation (FFT). Eight patients with congestive heart failure were selected for the study. FFT analyses have been performed for 614.4 sec. Out of the power spectrum, five parameters were extracted to characterize the CSR. The low peak frequencies in eight subjects were between 0.0179 Hz (56 sec) and 0.0081 Hz (123 sec). The algorithms used to detect CSR are the followings: (i) if the LFPA/ULFA ratios were above the absolute value of 1.0, and (ii) the LFPP/MLFP ratios were above the absolute values of 4.0, then the power spectrum is suggestive of CSR. We conclude that the automatic detection of CSR by heart rate spectral analysis during ambulatory ECG monitoring may afford a tool for the evaluation of the patients with congestive heart failure.

Mangiferin protects rat myocardial tissue against cyclophosphamide induced cardiotoxicity.

PubMed

Bhatt, Laxit; Sebastian, Binu; Joshi, Viraj

Mangiferin is a highly potent antioxidant present in mango leaves which is utilized for therapeutic purposes. The present study was undertaken to evaluate the cardioprotective effect of mangiferin against cyclophosphamide induced cardiotoxicity. Rats were treated with 100 mg/kg of mangiferin in alone and interactive groups for 10 days. Apart from normal and mangiferin control groups, all the groups were subjected to cyclophosphamide (200 mg/kg, i.p.) toxicity on Day 1 and effects of different treatments were analyzed by changes in serum biomarkers, tissue antioxidant levels, electrocardiographic parameters, lipid profile and histopathological evaluation. Mangiferin treated group showed decrease in serum biomarker enzyme levels and increase in tissue antioxidant levels. Compared to cyclophosphamide control group, mangiferin treated animals showed improvement in lipid profile, electrocardiographic parameters, histological score and mortality. The present findings clearly suggest the protective role of mangiferin as a powerful antioxidant preventing cardiotoxicity caused by cyclophosphamide. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

Yesterday and Today: A Few Words About the Development of Health Protection in Stalinabad

DTIC Science & Technology

1960-11-02

Medical Institute are enrolled more than two thousand students . Within the walls of the school future den- tists, obstetricians, pharmacists...18 X-ray and 12 physiotherapy departments, 12 clinical diagnostic units, and seven electrocardiographic units. Republic and city sanitation and

Courtyard. Left wall is corridor from 511 to 515. Right ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Courtyard. Left wall is corridor from 511 to 515. Right wall is the south side of 517. - Fitzsimons General Hospital, Physiotherapy & Electrocardiograph Department Building, North of Building No. 516, East of corridor connecting Building No. 511 to Building No. 515, Aurora, Adams County, CO

A case of acute paraplegia that improved with dialysis.

PubMed

Rajendiran, Govarthanan; Jayabalan, Rajamahesh; Chandrahasan, Saravanan; Mani, Ashwin Kumar

2008-01-01

Acute severe hyperkalemia can present as acute paraplegia independent of cardiac effects, even though cardiac muscle is more sensitive to serum potassium changes. We managed a patient with acute hyperkalemic paralysis who did not have threatening cardiac/electrocardiographic manifestations. The limb weakness became normal after hemodialysis.

Design Document. EKG Interpretation Program.

ERIC Educational Resources Information Center

Webb, Sandra M.

This teaching plan is designed to assist nursing instructors assigned to advanced medical surgical nursing courses in acquainting students with the basic skills needed to perform electrocardiographic (ECG or EKG) interpretations. The first part of the teaching plan contains a statement of purpose; audience recommendations; a flow chart detailing…

Improving pilot mental workload evaluation with combined measures.

PubMed

Wanyan, Xiaoru; Zhuang, Damin; Zhang, Huan

2014-01-01

Behavioral performance, subjective assessment based on NASA Task Load Index (NASA-TLX), as well as physiological measures indexed by electrocardiograph (ECG), event-related potential (ERP), and eye tracking data were used to assess the mental workload (MW) related to flight tasks. Flight simulation tasks were carried out by 12 healthy participants under different MW conditions. The MW conditions were manipulated by setting the quantity of flight indicators presented on the head-up display (HUD) in the cruise phase. In this experiment, the behavioral performance and NASA-TLX could reflect the changes of MW ideally. For physiological measures, the indices of heart rate variability (HRV), P3a, pupil diameter and eyelid opening were verified to be sensitive to MW changes. Our findings can be applied to the comprehensive evaluation of MW during flight tasks and the further quantitative classification.

Acquired left bundle branch block in an asymptomatic fighter pilot: a case report.

PubMed

Newman, D G

1999-12-01

This report describes a case of acquired left bundle branch block (LBBB) in an asymptomatic F/A-18 fighter pilot of the Royal Australian Air Force. The previously fit and healthy pilot was found to have LBBB on routine electrocardiographic screening prior to his annual aircrew medical. He was completely asymptomatic, and the only potential etiological factor was a short-lived acute gastrointestinal infectious illness some 4 mo previously. The pilot was extensively investigated with the full range of available diagnostic procedures, including coronary angiography and cardiac biopsy. No cause was determined for his LBBB pattern, and he was assessed as having normal cardiovascular function. The aeromedical disposition of this aviator and the issues involved in determining fitness to fly in such a case are discussed. The importance of thorough clinical investigation and appropriate follow-up are highlighted.

Determination of left ventricular volume, ejection fraction, and myocardial mass by real-time three-dimensional echocardiography

NASA Technical Reports Server (NTRS)

Qin, J. X.; Shiota, T.; Thomas, J. D.

2000-01-01

Reconstructed three-dimensional (3-D) echocardiography is an accurate and reproducible method of assessing left ventricular (LV) functions. However, it has limitations for clinical study due to the requirement of complex computer and echocardiographic analysis systems, electrocardiographic/respiratory gating, and prolonged imaging times. Real-time 3-D echocardiography has a major advantage of conveniently visualizing the entire cardiac anatomy in three dimensions and of potentially accurately quantifying LV volumes, ejection fractions, and myocardial mass in patients even in the presence of an LV aneurysm. Although the image quality of the current real-time 3-D echocardiographic methods is not optimal, its widespread clinical application is possible because of the convenient and fast image acquisition. We review real-time 3-D echocardiographic image acquisition and quantitative analysis for the evaluation of LV function and LV mass.

Spontaneous conversion of atrial fibrillation caused by severe hyperkalemia: A case report.

PubMed

Yan, Lihua; Jiang, Tingbo; Yang, Xiangjun; Xu, Mingzhu

2018-04-01

Hyperkalemia is a life-threatening electrolyte disturbance which could lead to arrhythmias and potentially death. An 82-year-old male patient who presented typical electrocardiographic indications of hyperkalemia, including the absence of P waves, prolongation of QRS complex, sinoventricular conduction, bradyarrhythmia and tall peaked T waves. He developed a rare self-defibrillation of atrial fibrillation to sinus rhythm due to hyperkalemia. Besides, he developed secondary thrombosis caused by abrupt termination of atrial fibrillation. This patient was diagnosed with hyperkalemia, hypertension, and AF. He was treated with an intravenous infusion of calcium gluconate, insulin and dextrose, an oral kayexalate, and emergency hemodialysis. The patient was managed effectively and discharged with stable status. Hyperkalemia could induce malignant arrhythmia with high mortality. Thus we suggested more attention be paid to monitoring electrolyte disorders and maintaining anticoagulation treatments to avoid thromboembolism.

Determination of left ventricular volume, ejection fraction, and myocardial mass by real-time three-dimensional echocardiography.

PubMed

Qin, J X; Shiota, T; Thomas, J D

2000-11-01

Reconstructed three-dimensional (3-D) echocardiography is an accurate and reproducible method of assessing left ventricular (LV) functions. However, it has limitations for clinical study due to the requirement of complex computer and echocardiographic analysis systems, electrocardiographic/respiratory gating, and prolonged imaging times. Real-time 3-D echocardiography has a major advantage of conveniently visualizing the entire cardiac anatomy in three dimensions and of potentially accurately quantifying LV volumes, ejection fractions, and myocardial mass in patients even in the presence of an LV aneurysm. Although the image quality of the current real-time 3-D echocardiographic methods is not optimal, its widespread clinical application is possible because of the convenient and fast image acquisition. We review real-time 3-D echocardiographic image acquisition and quantitative analysis for the evaluation of LV function and LV mass.

A microcontroller-based portable electrocardiograph recorder.

PubMed

Segura-Juárez, José J; Cuesta-Frau, David; Samblas-Pena, Luis; Aboy, Mateo

2004-09-01

We describe a low cost portable Holter design that can be implemented with off-the-shelf components. The recorder is battery powered and includes a graphical display and keyboard. The recorder is capable of acquiring up to 48 hours of continuous electrocardiogram data at a sample rate of up to 250 Hz.

A system for the automatic measurement and digital display of systolic and diastolic blood pressures

NASA Technical Reports Server (NTRS)

Schulze, A. E.

1971-01-01

Basic components of system are - occluding cuff with mounted cuff microscope, cuff pump deflator, pressure transducer, preamplifier unit, electrocardiograph machine, an analog to digital convertor unit, and digital display unit. System utilizes indirect auscultatory method, based on Korotkoff sounds, for measurement.

76 FR 43690 - Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-21

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0149] (Formerly 2007D-0309) Guidance for Industry and Food and Drug Administration Staff; Class II Special Controls Guidance Document: Electrocardiograph Electrodes; Availability AGENCY: Food and Drug...

Electrocardiographic, hemodynamic, and biochemical responses to acute particulate matter (PM) exposure in aged heart failure-prone rats

EPA Science Inventory

Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiac disease-especially heart failure (HF). The mechanisms explaining PM-induced exacerbation ofHF are unclear. Some o...

Particulate inhalation in rats causes concentration-dependent electrocardiographic, autonomic, and cardiac microRNA expression changes

EPA Science Inventory

Recently, investigators in key epidemiologic studies have demonstrated associations between fine particulate matter (PM)-associated metals and increased hospital admissions (Ni and V; Bell et al. 2009) and cardiovascular mortality (Ni and Fe; Ostro et a1. 2007). Residual oil fly ...

A case of acute paraplegia that improved with dialysis

PubMed Central

Rajendiran, Govarthanan; Jayabalan, Rajamahesh; Chandrahasan, Saravanan; Mani, Ashwin Kumar

2008-01-01

Acute severe hyperkalemia can present as acute paraplegia independent of cardiac effects, even though cardiac muscle is more sensitive to serum potassium changes. We managed a patient with acute hyperkalemic paralysis who did not have threatening cardiac/electrocardiographic manifestations. The limb weakness became normal after hemodialysis. PMID:19826591

Electrocardiographic and autonomic effects of acute particulate matter (PM) exposure in a rat model of cardiomyopathy

EPA Science Inventory

Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiac disease--especially heart failure (HF). Cardiomyopathy is the most common cause of heart failure. The mechanisms ...

III SBC Guidelines on the Analysis and Issuance of Electrocardiographic Reports - Executive Summary

PubMed Central

Pastore, Carlos Alberto; Samesima, Nelson; Pereira-Filho, Horacio Gomes

2016-01-01

The third version of the guidelines covers recently described topics, such as ion channel diseases, acute ischemic changes, the electrocardiogram in athletes, and analysis of ventricular repolarization. It sought to revise the criteria for overloads, conduction disorders, and analysis of data for internet transmission. PMID:27982266

Fishing for an ECG: A Student-Directed Electrocardiographic Laboratory Using Rainbow Trout

ERIC Educational Resources Information Center

Cotter, Paul A.; Rodnick, Kenneth J.

2007-01-01

Cardiac physiology is emphasized in many undergraduate physiology courses, but few nonmammalian vertebrate model systems exist that 1) can be studied fairly noninvasively, 2) are well suited for controlled experimentation, and 3) emphasize principles characteristic of the vertebrate heart. We have developed an inquiry-based…

Crisis management during anaesthesia: embolism

PubMed Central

Williamson, J; Helps, S; Westhorpe, R; Mackay, P

2005-01-01

Background: Embolism with gas, thrombus, fat, amniotic fluid, or particulate matter may occur suddenly and unexpectedly during anaesthesia, posing a diagnostic and management problem for the anaesthetist. Objectives: To examine the role of a previously described core algorithm "COVER ABCD–A SWIFT CHECK" supplemented by a specific sub-algorithm for embolism, in the management of embolism occurring in association with anaesthesia. Methods: The potential performance of this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved. Results: Among the first 4000 incidents reported to AIMS, 38 reports of embolism were found. A sudden fall in end-tidal carbon dioxide and oxygen saturation were the cardinal signs of embolism, each occurring in about two thirds of cases, with hypotension and electrocardiographic changes each occurring in about one third of cases. Conclusion: The potential value of an explicit structured approach to the diagnosis and management of embolism was assessed in the light of AIMS reports. It was considered that, correctly applied, it potentially would have led to earlier recognition of the problem and/or better management in over 40% of cases. PMID:15933290

Effect of granulocyte colony-stimulating factor on myocardium recovery in postinfarction period.

PubMed

Gol'dberg, E D; Dygai, A M; Zhdanov, V V; Stavrova, L A; Fomina, T I; Plotnikov, M B; Aliev, O I; Chernyshova, G A; Masycheva, V I; Sotnikova, N V

2005-03-01

The effect of Neutrostim (preparation of granulocytic colony-stimulating factor) on recovery of myocardial tissue after acute myocardial infarction was studied in rats. A course of Neutrostim after ligation of the left coronary artery led to normalization of electrocardiographic and morphological parameters of the myocardium after one month.

An unusual case of electrode misplacement: left arm and V(2) electrode reversal.

PubMed

García-Niebla, Javier; García, Pablo Llontop

2008-01-01

Accidental interchange between precordial and limb leads, although unusual, can be possible given that some of them share the same color. We present the case where interchange of V(2) and left arm cables produced significant electrocardiographic abnormalities, which created many doubts and discussion within the clinical team.

Divergent Electrocardiographic Responses to Whole and Particle-Free Diesel Exhaust Inhalation in Spontaneously Hypertensive Rats

EPA Science Inventory

Diesel exhaust (DE) is a major contributor to traffic-related fine PM2.5. While inroads have been made in understanding the mechanisms of PM related health effects, DE’s complex mixture of PM, gases and volatile organics makes it difficult to determine how the constituents contri...

A Criterion-Referenced Examination of Physician Competence.

ERIC Educational Resources Information Center

Norcini, John J.; And Others

1988-01-01

A test of skill in reading electrocardiographs (ECGs) was developed as a physician competence (PC) test. The criterion-referenced test ranked 1,825 persons taking the 1983 Certifying Examination in Cardiovascular Diseases (CECD) as expected on the basis of prior education and examination scores on the CECD. The ECG test modestly correlated with…

Electrocardiographic anxiety profiles improve speech anxiety.

PubMed

Kim, Pyoung Won; Kim, Seung Ae; Jung, Keun-Hwa

2012-12-01

The present study was to set out in efforts to determine the effect of electrocardiographic (ECG) feedback on the performance in speech anxiety. Forty-six high school students participated in a speech performance educational program. They were randomly divided into two groups, an experimental group with ECG feedback (N = 21) and a control group (N = 25). Feedback was given with video recording in the control, whereas in the experimental group, an additional ECG feedback was provided. Speech performance was evaluated by the Korean Broadcasting System (KBS) speech ability test, which determines the 10 different speaking categories. ECG was recorded during rest and speech, together with a video recording of the speech performance. Changes in R-R intervals were used to reflect anxiety profiles. Three trials were performed for 3-week program. Results showed that the subjects with ECG feedback revealed a significant improvement in speech performance and anxiety states, which compared to those in the control group. These findings suggest that visualization of the anxiety profile feedback with ECG can be a better cognitive therapeutic strategy in speech anxiety.

The T wave in the V10 precordial electrocardiographic lead is negative in healthy Chihuahua dogs.

PubMed

Dijkstra, Marieke; Szatmári, Viktor

2009-12-01

The T wave polarity in the V10 precordial electrocardiographic (ECG) lead in Chihuahuas is described as positive in the veterinary literature. The aim of this study was to investigate the polarity of the T wave in the V10 precordial ECG lead in clinically healthy Chihuahuas. Our null hypothesis was that healthy Chihuahuas have a negative T wave in V10. In this prospective study, 67 healthy breeder-owned Chihuahuas were used. A physical examination, 10-lead ECG and an echocardiogram were performed on each dog. No cardio-respiratory abnormalities were revealed in any of the otherwise healthy dogs. Three out of 67 ECGs were of insufficient quality because of baseline artifacts due to movement of the animal. Two other ECGs showed a nearly iso-electric T wave in the V10 lead. The remaining 62 ECGs showed negative T waves in the V10 lead. Right ventricular hypertrophy was excluded with echocardiography in all dogs. In contrast to previous reports, we found that healthy Chihuahuas have negative T wave in the V10 precordial ECG lead.

[Evaluation of intraventricular dyssynchrony by quantitative tissue velocity imaging in rats of post-infarction heart failure].

PubMed

Wang, Yan; Zhu, Wenhui; Duan, Xingxing; Zhao, Yongfeng; Liu, Wengang; Li, Ruizhen

2011-04-01

To evaluate intraventricular systolic dyssynchrony in rats with post-infarction heart failure by quantitative tissue velocity imaging combining synchronous electrocardiograph. A total of 60 male SD rats were randomly assigned to 3 groups: a 4 week post-operative group and an 8 week post-operation group (each n=25, with anterior descending branch of the left coronary artery ligated), and a sham operation group (n=10, with thoracotomy and open pericardium, but no ligation of the artery). The time to peak systolic velocity of regional myocardial in the rats was measured and the index of the left intraventricular dyssynchrony was calculated. All indexes of the heart function became lower as the heart failure worsened except the left ventricle index in the post-operative groups. All indexes of the dyssynchrony got longer in the post-operative groups (P<0.05), while the changes in the sham operation group were not significantly different (P>0.05). Quantitative tissue velocity imaging combining synchronous electrocardiograph can analyse the intraventricular systolic dyssynchrony accurately.

Portable electrocardiograph through android application.

PubMed

De Oliveira, Igor H; Cene, V H; Balbinot, A

2015-01-01

An electrocardiograph was designed and implemented, being capable of obtaining electrical signals from the heart, and sending this data via Bluetooth to a tablet, in which the signals are graphically shown. The user interface is developed as an Android application. Because of the technological progress and the increasing use of full portable systems, such as tablets and cell phones, it is important to understand the functioning and development of an application, which provides a basis for conducting studies using this technology as an interface. The project development includes concepts of electronics and its application to achieve a portable and functional final project, besides using a specific programmable integrated circuit for electrocardiogram, electroencephalogram and electromyogram, the ADS1294. Using a simulator of cardiac signals, 36 different waveforms were recorded, including normal sinus rhythm, arrhythmias and artifacts. Simulations include variations of heart rate from 30 to 190 beats per minute (BPM), with variations in peak amplitude of 1 mV to 2 mV. Tests were performed with a subject at rest and in motion, observing the signals obtained and the damage to their interpretation due to the introduction of muscle movement artifacts in motion situations.

Incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities - a nationwide population-based study.

PubMed

Lehtonen, Arttu O; Langén, Ville L; Puukka, Pauli J; Kähönen, Mika; Nieminen, Markku S; Jula, Antti M; Niiranen, Teemu J

Scant data exist on incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities in the general population. We recorded ECG and measured conventional cardiovascular risk factors in 5667 Finns who were followed up for incident atrial fibrillation (AF). We obtained repeat ECGs from 3089 individuals 11years later. The incidence rates of prolonged P-wave duration, abnormal P terminal force (PTF), left P-wave axis deviation, and right P-wave axis deviation were 16.0%, 7.4%, 3.4%, and 2.2%, respectively. Older age and higher BMI were associated with incident prolonged P-wave duration and abnormal PTF (P≤0.01). Higher blood pressure was associated with incident prolonged P-wave duration and right P-wave axis deviation (P≤0.01). During follow-up, only prolonged P-wave duration predicted AF (multivariable-adjusted hazard ratio, 1.38; P=0.001). Modifiable risk factors associate with P-wave abnormalities that are common and may represent intermediate steps of atrial cardiomyopathy on a pathway leading to AF. Copyright © 2017 Elsevier Inc. All rights reserved.

QRS-fragmentation: Case report and review of the literature.

PubMed

Illescas-González, Edgar; Araiza-Garaygordobil, Diego; Sierra Lara, Jorge Daniel; Ramirez-Salazar, Aristoteles; Sierra-Fernández, Carlos; Alexanderson-Rosas, Erick

Fragmentation of QRS complex (QRSf) is an easily evaluable, non-invasive electrocardiographic parameter that represents depolarisation anomalies and has been associated with several adverse outcomes, such as sudden death, fibrosis, arrhythmic burden, and a worse prognosis in different conditions, including coronary artery disease (CAD). The case is presented of a 69-year old male referred due to symptoms of chronic stable angina. His electrocardiogram showed sinus rhythm, absence of Q waves, but the presence of QRSf in the inferior leads and V4-V6. A Tc-99 myocardial perfusion SPECT scan revealed a fixed perfusion defect in the inferolateral region, corresponding to the finding of QRSf. QRSf is an easily valuable electrocardiographic marker with relative sensitivity, but poor specificity. Its routine clinical application could contribute to an increase in the suspicion of coronary artery disease. The presence of fragmented QRS represents distortion of signal conduction and depolarisation, which is related to myocardial scar or myocardial fibrosis. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

High Frequency of Human Blood in Triatoma dimidiata Captured Inside Dwellings in a Rural Community in the Yucatan Peninsula, Mexico, but Low Antibody Seroprevalence and Electrocardiographic Findings Compatible with Chagas Disease in Humans

PubMed Central

Monteon, Victor; Alducin, César; Hernández, Jorge; Ramos-Ligonio, Angel; Lopez, Ruth

2013-01-01

We studied a small rural community of 411 inhabitants localized in the state of Campeche in the Yucatan Peninsula, Mexico. In 44 collected triatomines captured inside the houses, human feeding source was revealed in 23 of 44 (52%) samples, and chicken feeding source was revealed in 16 of 44 (36%) samples. In a set of 29 triatomines, mouse was the feeding source in 13 (44%) samples, and dog was the feeding source in 7 (24%) samples. Infection index with Trypanosoma cruzi in collected triatomines was 38%, and all parasites belonged to discrete type unit I. Inhabitants referred high contact with triatomine's bite in 60 of 128 (47%) samples, but seroprevalence was 2.3% (3/128). Evidence of electrocardiographic alteration compatible with Chagas disease was observed only in one asymptomatic seropositive subject. In conclusion, Triatoma dimidiata in this region are preferentially infected with T. cruzi I and feed on human beings with relative high frequency, but seroprevalence and Chagas disease in humans is relatively low. PMID:23296447

Microengineered Conductive Elastomeric Electrodes for Long-Term Electrophysiological Measurements with Consistent Impedance under Stretch

PubMed Central

Hu, Dinglong; Cheng, Tin Kei; Xie, Kai; Lam, Raymond H. W.

2015-01-01

In this research, we develop a micro-engineered conductive elastomeric electrode for measurements of human bio-potentials with the absence of conductive pastes. Mixing the biocompatible polydimethylsiloxane (PDMS) silicone with other biocompatible conductive nano-particles further provides the material with an electrical conductivity. We apply micro-replica mold casting for the micro-structures, which are arrays of micro-pillars embedded between two bulk conductive-PDMS layers. These micro-structures can reduce the micro-structural deformations along the direction of signal transmission; therefore the corresponding electrical impedance under the physical stretch by the movement of the human body can be maintained. Additionally, we conduct experiments to compare the electrical properties between the bulk conductive-PDMS material and the microengineered electrodes under stretch. We also demonstrate the working performance of these micro-engineered electrodes in the acquisition of the 12-lead electrocardiographs (ECG) of a healthy subject. Together, the presented gel-less microengineered electrodes can provide a more convenient and stable bio-potential measurement platform, making tele-medical care more achievable with reduced technical barriers for instrument installation performed by patients/users themselves. PMID:26512662

Evaluation of Tp-e interval and Tp-e/QT ratio in patients with ankylosing spondylitis.

PubMed

Acar, Gurkan; Yorgun, Hikmet; Inci, Mehmet Fatih; Akkoyun, Murat; Bakan, Betul; Nacar, Alper Bugra; Dirnak, Imran; Cetin, Gozde Yildirim; Bozoglan, Orhan

2014-03-01

Ankylosing spondylitis (AS) is a chronic multi-systemic inflammatory rheumatic disorder. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with AS, and to assess the relation with inflammation. Sixty-two patients with AS and 50 controls were included. Tp-e interval and Tp-e/QT ratio were measured from a 12-lead electrocardiogram, and the Tp-e interval corrected for heart rate. The plasma level of high sensitive C-reactive protein (hsCRP) was measured. These parameters were compared between groups. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in AS patients compared to the controls (31.7 ± 9.6 vs 28.2 ± 7.4 and 35.8 ± 11.5 vs 30.6 ± 7.9 ms, P = 0.03 and P = 0.007, respectively). cTp-e interval and Tp-e/QT ratio were also significantly higher in AS patients (92.1 ± 10.2 vs 75.8 ± 8.4 and 0.22 ± 0.02 vs 0.19 ± 0.02 ms, all P values <0.001). cTp-e interval and Tp-e/QT ratio were significantly correlated with hsCRP (r = 0.63, P < 0.001 and r = 0.49, P < 0.001, respectively). Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in AS patients. These electrocardiographic ventricular repolarization indexes were significantly correlated with the plasma level of hsCRP.

Evaluation of Tp-e interval and Tp-e/QT ratio in patients with ankylosing spondylitis.

PubMed

Acar, Gurkan; Yorgun, Hikmet; Inci, Mehmet Fatih; Akkoyun, Murat; Bakan, Betul; Nacar, Alper Bugra; Dirnak, Imran; Cetin, Gozde Yildirim; Bozoglan, Orhan

2013-04-12

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic multi-systemic inflammatory rheumatic disorder. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with AS, and to assess the relation with inflammation. METHODS: Sixty-two patients with AS and 50 controls were included. Tp-e interval and Tp-e/QT ratio were measured from a 12-lead electrocardiogram, and the Tp-e interval corrected for heart rate. The plasma level of high sensitive C-reactive protein (hsCRP) was measured. These parameters were compared between groups. RESULTS: In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in AS patients compared to the controls (31.7 ± 9.6 vs 28.2 ± 7.4 and 35.8 ± 11.5 vs 30.6 ± 7.9 ms, P = 0.03 and P = 0.007, respectively). cTp-e interval and Tp-e/QT ratio were also significantly higher in AS patients (92.1 ± 10.2 vs 75.8 ± 8.4 and 0.22 ± 0.02 vs 0.19 ± 0.02 ms, all P values <0.001). cTp-e interval and Tp-e/QT ratio were significantly correlated with hsCRP (r = 0.63, P < 0.001 and r = 0.49, P < 0.001, respectively). CONCLUSIONS: Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in AS patients. These electrocardiographic ventricular repolarization indexes were significantly correlated with the plasma level of hsCRP.

Clinical utility of T-wave alternans

NASA Technical Reports Server (NTRS)

Armoundas, A. A.; Cohen, R. J.

1997-01-01

Electrical alternans represents a variation in the morphology of electrocardiographic complexes on an every-other-beat basis in an ABABAB... pattern. Apparent electrical alternans associated with pericardial effusion results from rotation of the heart in the pericardial sac, and not true alternation in electrical conduction patterns. In contrast, true electrical alternans results from an alternation in electrical conduction patterns in the heart itself. Repolarization alternans is true electrical alternans associated with the ST segment and T wave of the electrocardiogram (ECG). Here we will focus on T-wave alternans (TWA) and its association with susceptibility to ventricular tachyarrhythmias. Electrical alternans was reported in the literature as early as 1909. Historically, electrical alternans has been regarded as a fairly rare electrocardiographic abnormality. Case reports of electrical alternans have been associated with a variety of disease states, including acute ischemia, Prinzmetal's angina, a variety of electrolyte abnormalities, and the long QT syndrome. Interestingly, patients born with the prolonged QT syndrome have a very high incidence of sudden cardiac death at an early age. Schwartz and Malliani showed that patients with the prolonged QT syndrome who do not demonstrate alternans at rest, may evidence alternans during stress such as emotional excitement. Thus, over the years electrical alternans has been associated anecdotally with conditions associated with an increased risk of ventricular arrhythmias. In 1948, Kalter reviewed the world literature on electrical alternans and found a total of 41 reported cases. In addition, he reviewed clinical ectrocardiograms from 6059 patients and found five new cases (incidence of less than 1 in 1000 patients). Interestingly, he found a very high mortality, 62%, associated with this condition. Despite the clinical associations reported in the literature, the consensus view of electrical alternans until recent years has been that alternans is an electrocardiographic curiosity rarely encountered in clinical practice which, when identified, does not have specific clinical significance.

Detection of QT prolongation using a novel electrocardiographic analysis algorithm applying intelligent automation: prospective blinded evaluation using the Cardiac Safety Research Consortium electrocardiographic database.

PubMed

Green, Cynthia L; Kligfield, Paul; George, Samuel; Gussak, Ihor; Vajdic, Branislav; Sager, Philip; Krucoff, Mitchell W

2012-03-01

The Cardiac Safety Research Consortium (CSRC) provides both "learning" and blinded "testing" digital electrocardiographic (ECG) data sets from thorough QT (TQT) studies annotated for submission to the US Food and Drug Administration (FDA) to developers of ECG analysis technologies. This article reports the first results from a blinded testing data set that examines developer reanalysis of original sponsor-reported core laboratory data. A total of 11,925 anonymized ECGs including both moxifloxacin and placebo arms of a parallel-group TQT in 181 subjects were blindly analyzed using a novel ECG analysis algorithm applying intelligent automation. Developer-measured ECG intervals were submitted to CSRC for unblinding, temporal reconstruction of the TQT exposures, and statistical comparison to core laboratory findings previously submitted to FDA by the pharmaceutical sponsor. Primary comparisons included baseline-adjusted interval measurements, baseline- and placebo-adjusted moxifloxacin QTcF changes (ddQTcF), and associated variability measures. Developer and sponsor-reported baseline-adjusted data were similar with average differences <1 ms for all intervals. Both developer- and sponsor-reported data demonstrated assay sensitivity with similar ddQTcF changes. Average within-subject SD for triplicate QTcF measurements was significantly lower for developer- than sponsor-reported data (5.4 and 7.2 ms, respectively; P < .001). The virtually automated ECG algorithm used for this analysis produced similar yet less variable TQT results compared with the sponsor-reported study, without the use of a manual core laboratory. These findings indicate that CSRC ECG data sets can be useful for evaluating novel methods and algorithms for determining drug-induced QT/QTc prolongation. Although the results should not constitute endorsement of specific algorithms by either CSRC or FDA, the value of a public domain digital ECG warehouse to provide prospective, blinded comparisons of ECG technologies applied for QT/QTc measurement is illustrated. Copyright © 2012 Mosby, Inc. All rights reserved.

Electrocardiographic abnormalities in amateur male marathon runners.

PubMed

Kaleta, Anna M; Lewicka, Ewa; Dąbrowska-Kugacka, Alicja; Lewicka-Potocka, Zuzanna; Wabich, Elżbieta; Szerszyńska, Anna; Dyda, Julia; Sobolewski, Jakub; Koenner, Jakub; Raczak, Grzegorz

2018-06-18

Sports activity has become extremely popular among amateurs. Electrocardiography is a useful tool in screening for cardiac pathologies in athletes; however, there is little data on electrocardiographic abnormalities in the group of amateur athletes. The aim of this study was to analyze the abnormalities in resting and exercise electrocardiograms (ECGs) in a group of amateur athletes, and try to determine whether the criteria applied for the general population or for athletes' ECGs should be implemented in this group. In 40 amateur male marathon runners, 3 consecutive 12-lead ECGs were performed: 2-3 weeks before (stage 1), just after the run (stage 2) and 2-3 weeks after the marathon (stage 3). Resting (stage 1) and exercise (stage 2) ECGs were analyzed following the refined criteria for the assessment of athlete's ECG (changes classified as training-related, borderline or training-unrelated). In resting ECGs, at least 1 abnormality was found in 92.5% of the subjects and the most common was sinus bradycardia (62.5%). In post-exercise ECGs, at least 1 abnormality was present in 77.5% of the subjects and the most common was right atrium enlargement (RAE) (42.5%). Training-related ECG variants were more frequent at rest (82.5% vs 42.5%; p = 0.0008), while borderline variants - after the run (22.5% vs 57.5%; p = 0.0004). Training-unrelated abnormalities were found in 15% and 10% of the subjects, respectively (p-value - nonsignificant), and the most common was T-wave inversion. Even if the refined criteria rather than the criteria used for normal sedentary population were applied, the vast majority of amateur runners showed at least 1 abnormality in resting ECGs, which were mainly training-related variants. However, at rest, in 15% of the subjects, pathologic training-unrelated abnormalities were found. The most frequent post-exercise abnormality was right atrial enlargement. General electrocardiographic screening in amateur athletes should be taken into consideration.

Acute organophosphorus poisoning complicated by acute coronary syndrome.

PubMed

Pankaj, Madhu; Krishna, Kavita

2014-07-01

We report a case of 30 year old alcoholic male admitted with vomiting, drowsiness, limb weakness and fasciculations after alleged history of consumption of 30 ml of chlorpyriphos insecticide. He had low serum cholinesterase levels. With standard treatment for organophosphorus poisoning (OPP), he improved gradually until day 5, when he developed neck and limb weakness and respiratory distress. This intermediate syndrome was treated with oximes, atropine and artificial ventilation. During treatment, his ECG showed fresh changes of ST elevation. High CPK & CPK-MB levels, septal hypokinesia on 2D echo suggested acute coronary syndrome. Coronary angiography was postponed due to his bedridden and obtunded status. The patient finally recovered fully by day 15 and was discharged. Acute coronary syndrome is a rare occurrence in OP poisoning. The present case thus emphasises the need for careful electrocardiographic and enzymatic monitoring of all patients of organophosphorus poisoning to prevent potential cardiac complication which can prove fatal.

Chloroquine-induced cardiomyopathy: a reversible cause of heart failure.

PubMed

Yogasundaram, Haran; Hung, Whitney; Paterson, Ian D; Sergi, Consolato; Oudit, Gavin Y

2018-06-01

Chloroquine (CQ) and hydroxychloroquine (HCQ) are anti-rheumatic medications frequently used in the treatment of connective tissue disorders. We present the case of a 45-year-old woman with CQ-induced cardiomyopathy leading to severe heart failure. Electrocardiographic abnormalities included bifascicular block, while structural disease consisted of severe biventricular and biatrial hypertrophy. Appropriate diagnosis via endomyocardial biopsy led to cessation of CQ and subsequent dramatic improvement in symptoms and structural heart disease. Cardiac toxicity is an under-recognized adverse effect of CQ/HCQ leading to cardiomyopathy with concentric hypertrophy and conduction abnormalities, with the potential for significant morbidity and mortality. Predisposing factors for CQ/HCQ-induced cardiomyopathy have been proposed. CQ/HCQ cardiomyopathy is a phenocopy of Fabry disease, and α-galactosidase A polymorphism may account for some heterogeneity of disease presentation. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Nonintrusive biosignal measurement system in a vehicle.

PubMed

Lee, Haet Bit; Choi, Jong Min; Kim, Jung Soo; Kim, Yun Seong; Baek, Hyun Jae; Ryu, Myung Suk; Sohn, Ryang Hee; Park, Kwang Suk

2007-01-01

Measurement of driver's state is important in both daily healthcare and prevention of car accidents. Existing measurement methods, however, are too complex and uncomfortable to measure for everyday. A nonintrusive biosignal monitoring system is demanded for increasing the accessibility. In this paper, we proposed a nonintrusive measurement system integrated in a vehicle for recording electrocardiographic (ECG) signals and tested the performance of the system. The system consists of dry electrodes attached to the steering wheel and a wireless communication module using a Bluetooth device. ECG signals measured by our system were compared with those by a conventional system employing wet electrodes during real city road driving. Various parameters used for HRV analysis in time and frequency domain showed no significant differences between the two simultaneously measured ECG signals. The result implies the possibility that developed system could have a potential to monitor health information in a vehicle instead of commercial equipments.

Electrocardiographic Abnormalities in Elderly Chagas Disease Patients: 10‐Year Follow‐Up of the Bambuí Cohort Study of Aging

PubMed Central

Ribeiro, Antonio Luiz P.; Marcolino, Milena S.; Prineas, Ronald J.; Lima‐Costa, Maria Fernanda

2014-01-01

Background Electrocardiography has been considered an important tool in the management of Chagas disease (ChD) patients, although its value in elderly infected patients is unknown. This study was designed to investigate the prevalence and prognostic value of electrocardiographic abnormalities in Trypanosoma cruzi infected and noninfected older adults. Methods and Results We studied 1462 participants in Bambuí City, Brazil, with electrocardiogram (ECG) records classified by the Minnesota Code. Follow‐up time was 10 years; the endpoint was mortality. Adjustment for potential confounding variables included age, gender, conventional risk factors, and B‐type natriuretic peptide (BNP). The mean age was 69 years (60.9% women). The prevalence of ChD was 38.1% (n=557). ECG abnormalities were more frequent in ChD patients (87.6% versus 77.7%, P<0.001). Right bundle branch block (RBBB) with left anterior hemiblock (LAH) was strongly related to ChD (OR: 11.99 [5.60 to 25.69]). During the mean follow‐up time of 8.7 years, 556 participants died (253 with ChD), and only 89 were lost to follow‐up. ECG variables of independent prognostic value for death in ChD included absence of sinus rhythm, frequent ventricular and supraventricular premature beats, atrial fibrillation, RBBB, old and possible old myocardial infarction, and left ventricular hypertrophy. The presence of any major ECG abnormalities doubled the risk of death in ChD patients (HR: 2.18 [1.35 to 3.53]), but it also increased the risk in non‐ChD subjects (HR: 1.50 [1.07 to 2.10]); the risk of death increased with the number of major abnormalities in the same patient. Conclusion ECG abnormalities are more common among elderly Chagas disease patients and strongly predict adverse outcomes. PMID:24510116

Myogenic nature of insect heartbeat and intestinal peristalsis, revealed by neuromuscular paralysis caused by the sting of a braconid wasp.

PubMed

Sláma, Karel; Lukáš, Jan

2011-02-01

Larvae of the greater waxmoth (Galleria mellonella) become paralysed by the venom of the braconid wasp (Habrobracon hebetor) a few minutes after intoxication. The profound neuromuscular paralysis, which may last for several weeks, includes all somatic muscles that are innervated through neuromuscular transmission. The peristaltic contractions of the heart and intestine, which are regulated by the depolarisation potentials of the myocardium or intestinal epithelial muscles, remain unaffected and fully functional. Heartbeat patterns and intestinal pulsations were monitored in the motionless, paralysed larvae by means of advanced electrocardiographic recording methods (contact thermography, pulse-light optocardiography). The records revealed more or less constant cardiac pulsations characterised by 20-25 systolic contractions per minute. The contractions were peristaltically propagated in the forward (anterograde) direction, with a more or less constant speed of 10mm per second (23-25°C). Additional electrocardiographic investigations on larvae immobilised by decapitation revealed the autonomic (brain independent) nature of heartbeat regulation. Sectioning performed in the middle of the heart (4th abdominal segment) seriously impaired the pacemaker rhythmicity and slowed down the rate of heartbeat in the anterior sections. By contrast, the functions of the posterior compartments of the disconnected heart remained unaffected. These results confirmed our previous conclusions about the existence of an autonomic, myogenic, pacemaker nodus in the terminal part of an insect heart. They show an analogy to the similar myogenic, sinoatrial or atrioventricular nodi regulating rhythmicity of the human heart. Peristaltic contractions of the intestine also represent a purely myogenic system, which is fully functional in larvae with complete neuromuscular paralysis. Unlike the constant anterograde direction of the heartbeat, intestinal peristaltic waves periodically reversed anterograde and retrograde directions. A possibility that the functional similarity between insect and human hearts may open new avenues in the field of comparative cardiology has been discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Electrocardiographic Characteristics of Potential Organ Donors and Associations with Cardiac Allograft Utilization

PubMed Central

Khush, Kiran K.; Menza, Rebecca; Nguyen, John; Goldstein, Benjamin A.; Zaroff, Jonathan G.; Drew, Barbara J.

2012-01-01

Background Current regulations require that all cardiac allograft offers for transplantation must include an interpreted 12-lead electrocardiogram (ECG). However, little is known about the expected ECG findings in potential organ donors, or the clinical significance of any identified abnormalities in terms of cardiac allograft function and suitability for transplantation. Methods and Results A single experienced reviewer interpreted the first ECG obtained after brainstem herniation in 980 potential organ donors managed by the California Transplant Donor Network from 2002-2007. ECG abnormalities were summarized, and associations between specific ECG findings and cardiac allograft utilization for transplantation were studied. ECG abnormalities were present in 51% of all cases reviewed. The most common abnormalities included voltage criteria for left ventricular hypertrophy (LVH), prolongation of the corrected QT interval (QTc), and repolarization changes (ST/T wave abnormalities). Fifty seven percent of potential cardiac allografts in this cohort were accepted for transplantation. LVH on ECG was a strong predictor of allograft non-utilization. No significant associations were seen between QTc prolongation, repolarization changes and allograft utilization for transplantation, after adjusting for donor clinical variables and echocardiographic findings. Conclusions We have performed the first comprehensive study of ECG findings in potential donors for cardiac transplantation. Many of the common ECG abnormalities seen in organ donors may result from the heightened state of sympathetic activation that occurs after brainstem herniation, and are not associated with allograft utilization for transplantation. PMID:22615333

Biomedical Telectrodes

NASA Technical Reports Server (NTRS)

Shepherd, C. K.

1989-01-01

Compact transmitters eliminate need for wires to monitors. Biomedical telectrode is small electronic package that attaches to patient in manner similar to small adhesive bandage. Patient wearing biomedical telectrodes moves freely, without risk of breaking or entangling wire connections. Especially beneficial to patients undergoing electrocardiographic monitoring in intensive-care units in hospitals. Eliminates nuisance of coping with wire connections while dressing and going to toilet.

Occupational Survey Report, AFSC 4H0X1 Cardiopulmonary Laboratory

DTIC Science & Technology

2004-02-01

Health Care Systems (CHCS) 63 Devices, Oxygen (O2) Humidification (Bubble) 63 Electrocardiographic Machines 63 Incentive Spirometer 63 Devices...3.63 63 67 2.91 8 E0180 Maintain open airways 6.74 56 60 5.36 18 E0183 Perform bedside spirometry 5.16 31 33 4.54 12 * Mean TE Rating is 3.18

Acute Electrocardiographic ST Segment Elevation May Predict Hypotension in a Swine Model of Severe Cyanide Toxicity

DTIC Science & Technology

2012-04-21

model with severe acidosis (pH 6.8), hyperkalemia (up to 10 meq/L), hypoglycemia, and hypoxia and reported that ECG electrical changes were not directly...hypoxia, hyperkalemia , and acidosis on intracellular and extracellular poten tials and metabolism in the isolated porcine heart. Circ Res 46 (5):634

Clinical trials of a personal electrocardiograph

NASA Astrophysics Data System (ADS)

Boyakhchyan, A.; Lezhnina, I.; Overchuk, K.; Perchatkin, V.; Lvova, A.; Alexander, U.

2018-05-01

The article describes the results of a clinical trial at the Cardiology Research Institute in Tomsk. Clinical trials were conducted to identify different important information for diagnosis. These tests were also conducted to remotely monitor the treatment of patients who had already been discharged from the hospital.The study involved 15 patients, the most interesting cases are described in this article.

Evaluation of 5 Hour Energy Drink on the Blood Pressure and Electrocardiograph Parameters on Young Healthy Volunteers: A Randomized, Double Blind, Crossover, Placebo-Controlled Trial (Presentation)

DTIC Science & Technology

2014-02-11

other substances. • There have been reports of atrial fibrillation , Takotsubo cardiomyopathy and sudden cardiac deaths in healthy individuals...baseline cardiac rhythm, history of atrial or ventricular arrhythmia, baseline corrected QT (QTc) interval greater than 440 milliseconds (msec

The experience of using the personal electrocardiograph “ECG-Express”

NASA Astrophysics Data System (ADS)

Lezhnina, I. A.; Overchuk, K. V.; Uvarov, A. A.; Perchatkin, V. A.; Lvova, A. B.

2017-08-01

The article describes the results of testing ECG-Express devices, previously developed at the Tomsk Polytechnic University. The testing was carried out on the basis of Tomsk Scientific Research Institute of Cardiology. Here we show the argumentation for application of such a devices in medical practice as well as number of cases of successful use.

An unusual ST-segment elevation: apical hypertrophic cardiomyopathy shows the ace up its sleeve.

PubMed

de Santis, Francesco; Pergolini, Amedeo; Zampi, Giordano; Pero, Gaetano; Pino, Paolo Giuseppe; Minardi, Giovanni

2013-01-01

Apical hypertrophic cardiomyopathy is part of the broad clinical and morphologic spectrum of hypertrophic cardiomyopathy. We report a patient with electrocardiographic abnormalities in whom acute coronary syndrome was excluded and apical hypertrophic cardiomyopathy was demonstrated by careful differential diagnosis. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Changes in electrocardiographic findings after closed thoracostomy in patients with spontaneous pneumothorax

PubMed Central

Lee, Wonjae; Lee, Yoonje; Kim, Changsun; Choi, Hyuk Joong; Kang, Bossng; Lim, Tae Ho; Oh, Jaehoon; Kang, Hyunggoo; Shin, Junghun

2017-01-01

Objective We aimed to describe electrocardiographic (ECG) findings in spontaneous pneumothorax patients before and after closed thoracostomy. Methods This is a retrospective study which included patients with spontaneous pneumothorax who presented to an emergency department of a tertiary urban hospital from February 2005 to March 2015. The primary outcome was a difference in ECG findings between before and after closed thoracostomy. We specifically investigated the following ECG elements: PR, QRS, QTc, axis, ST segments, and R waves in each lead. The secondary outcomes were change in ST segment in any lead and change in axis after closed thoracostomy. Results There were two ECG elements which showed statistically significant difference after thoracostomy. With right pneumothorax volume of greater than 80%, QTc and the R waves in aVF and V5 significantly changed after thoracostomy. With left pneumothorax volume between 31% and 80%, the ST segment in V2 and the R wave in V1 significantly changed after thoracostomy. However, majority of ECG elements did not show statistically significant alteration after thoracostomy. Conclusion We found only minor changes in ECG after closed thoracostomy in spontaneous pneumothorax patients. PMID:28435901

A non-contact capacitance based electrocardiograph and associated heart-rate detection using enhanced Fourier interpolation method.

PubMed

Kumar Thakur, Rupak; Anoop, C S

2015-08-01

Cardio-vascular health monitoring has gained considerable attention in the recent years. Principle of non-contact capacitive electrocardiograph (ECG) and its applicability as a valuable, low-cost, easy-to-use scheme for cardio-vascular health monitoring has been demonstrated in some recent research papers. In this paper, we develop a complete non-contact ECG system using a suitable front-end electronic circuit and a heart-rate (HR) measurement unit using enhanced Fourier interpolation technique. The front-end electronic circuit is realized using low-cost, readily available components and the proposed HR measurement unit is designed to achieve fairly accurate results. The entire system has been extensively tested to verify its efficacy and test results show that the developed system can estimate HR with an accuracy of ±2 beats. Detailed tests have been conducted to validate the performance of the system for different cloth thicknesses of the subject. Some basic tests which illustrate the application of the proposed system for heart-rate variability estimation has been conducted and results reported. The developed system can be used as a portable, reliable, long-term cardiac health monitoring device and can be extended to human drowsiness detection.

Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.

PubMed

Ueda, Tomohiro; Teshima, Hideki; Fukunaga, Shuji; Aoyagi, Shigeaki; Tanaka, Hiroyuki

2013-01-01

This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position. Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; P<0.0001). MDCT can be used to clearly visualize subprosthetic pannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.

Clinical significance of automatic warning function of cardiac remote monitoring systems in preventing acute cardiac episodes

PubMed Central

Chen, Shou-Qiang; Xing, Shan-Shan; Gao, Hai-Qing

2014-01-01

Objective: In addition to ambulatory Holter electrocardiographic recording and transtelephonic electrocardiographic monitoring (TTM), a cardiac remote monitoring system can provide an automatic warning function through the general packet radio service (GPRS) network, enabling earlier diagnosis, treatment and improved outcome of cardiac diseases. The purpose of this study was to estimate its clinical significance in preventing acute cardiac episodes. Methods: Using 2 leads (V1 and V5 leads) and the automatic warning mode, 7160 patients were tested with a cardiac remote monitoring system from October 2004 to September 2007. If malignant arrhythmias or obvious ST-T changes appeared in the electrocardiogram records was automatically transferred to the monitoring center, the patient and his family members were informed, and the corresponding precautionary or therapeutic measures were implemented immediately. Results: In our study, 274 cases of malignant arrhythmia, including sinus standstill and ventricular tachycardia, and 43 cases of obvious ST-segment elevation were detected and treated. Because of early detection, there was no death or deformity. Conclusions: A cardiac remote monitoring system providing an automatic warning function can play an important role in preventing acute cardiac episodes. PMID:25674124

The Telemetric and Holter ECG Warehouse Initiative (THEW): a Data Repository for the Design, Implementation and Validation of ECG-related Technologies

PubMed Central

Couderc, Jean-Philippe

2011-01-01

We present an initiative supported by the National Heart Lung, and Blood Institute and the Food and Drug Administration for the development of a repository containing continuous electrocardiographic information to be shared with the worldwide scientific community. We believe that sharing data reinforces open scientific inquiry. It encourages diversity of analysis and opinion while promoting new research and facilitating the education of new researchers. In this paper, we present the resources available in this initiative for the scientific community. We describe the set of ECG signals currently hosted and we briefly discuss the associated clinical information (medical history. Disease and study-specific endpoints) and software tools we propose. Currently, the repository contains more than 250GB of data from eight clinical studies including healthy individuals and cardiac patients. This data is available for the development, implementation and validation of technologies related to body-surface ECGs. To conclude, the Telemetric and Holter ECG Warehouse (THEW) is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. PMID:21097349

Nuclear cardiology

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

Penkava, R.R.

1985-05-01

Radionuclide cardiac imaging is a safe, noninvasive alternative to cardiac catheterization for observation and evaluation of cardiac wall motion and calculation of ejection fraction. Nuclide imaging offers a greater degree of sensitivity and specificity in detecting myocardial ischemia and infarction than do conventional electrocardiographic and cardiac enzyme studies. It is especially useful in problem cases. Myocardial infarction can usually be evaluated with respect to size and relative age of infarction.

Olanzapine induced Q-Tc shortening.

PubMed

Shoja Shafti, Saeed; Fallah Jahromi, Parisa

2014-12-01

Prolongation of Q-Tc interval is commonly accepted as a surrogate marker for the ability of a drug to cause torsade de pointes. In the present study, safety of olanzapine versus risperidone was compared among a group of patients with schizophrenia to see the frequency of the electrocardiographic alterations induced by those atypical antipsychotics. Two hundred and sixty-eight female inpatients with schizophrenia entered in one of the two parallel groups to participate in an open study for random assignment to olanzapine (n = 148) or risperidone (n = 120). Standard 12-lead surface electrocardiogram (ECG) was taken from each patient at baseline, before initiation of treatment, and then at the end of management, just before discharge. The parameters that were assessed included heart rate (HR), P-R interval, QRS interval, Q-T interval (corrected = Q-Tc), ventricular activation time (VAT), ST segment, T wave, axis of QRS, and finally, interventricular conduction process. A total of 37.83% of cases in the olanzapine group and 30% in the risperidone group showed some Q-Tc changes; 13.51% and 24.32% of the patients in the olanzapine group showed prolongation and shortening of the Q-Tc, respectively, while changes in the risperidone group were restricted to only prolongation of Q-Tc. Comparison of means showed a significant increment in Q-Tc by risperidone (p = 0.02). Also, comparison of proportions in the olanzapine group showed significantly more cases with shortening of Q-Tc versus its prolongation (p = 0.01). No significant alterations with respect to other variables were evident. Olanzapine and risperidone had comparable potentiality for induction of Q-Tc changes, while production of further miscellaneous alterations in ECG was more observable in the olanzapine group compared with the risperidone group. Also shortening of Q-Tc was specific to olanzapine.

Pharmacokinetics and electrophysiological effects of sotalol hydrochloride in horses.

PubMed

Broux, B; De Clercq, D; Decloedt, A; Vera, L; Devreese, M; Gehring, R; Croubels, S; van Loon, G

2018-05-01

Arrhythmias in horses may require long-term anti-arrhythmic therapy. Unfortunately, oral anti-arrhythmic drugs for use in horses are currently scarce. In human patients and small animals, sotalol, a β-blocker with class III anti-arrhythmic properties, is often used for long-term treatment. To determine the pharmacokinetics of sotalol at multiple oral dosages in unfasted horses, as well as the effects on electro- and echocardiographic measurements, right atrial and ventricular monophasic action potential (MAP) and effective refractory period (ERP). Placebo controlled, double-blinded experiment. Six healthy, unfasted Warmblood horses were given either 0, 2, 3 or 4 mg/kg bodyweight (bwt) sotalol orally (PO) twice daily (bid) for 9 days in a randomised cross-over design. Echocardiography and surface electrocardiography were performed and plasma concentrations of sotalol and right atrial and right ventricular MAPs and ERPs were determined at steady-state conditions. Statistical analysis was performed using a repeated measures univariate analysis with post hoc Bonferroni corrections. Calculated mean steady-state plasma concentrations determined by nonlinear mixed-effect modelling were 287 (range 234-339), 409 (359-458) and 543 (439-646) ng/mL for 2, 3 and 4 mg/kg bwt sotalol PO bid respectively. Sotalol significantly increased the QT interval and ERPs, but, despite increasing plasma concentrations, higher dosages did not result in a progressive increase in QT interval or ERPs. Echocardiographic and other electrocardiographic measurements did not change significantly. MAP durations at 90% repolarisation were not significantly different during sotalol treatment. Besides transient local sweating, no side effects were noted. Study size and ad libitum feeding of hay. Sotalol at a dose of 2, 3 and 4 mg/kg bwt PO bid increases the QT interval and ERP and might be a useful drug for long-term anti-arrhythmic therapy in horses. © 2017 EVJ Ltd.

Bradycardia and Hypothermia Complicating Azithromycin Treatment.

PubMed

Benn, Kerri; Salman, Sam; Page-Sharp, Madhu; Davis, Timothy M E; Buttery, Jim P

2017-08-11

BACKGROUND Azithromycin is a macrolide antibiotic widely used to treat respiratory, urogenital, and other infections. Gastrointestinal upset, headache, and dizziness are common adverse effects, and prolongation of the rate-corrected electrocardiographic QT interval and malignant arrhythmias have been reported. There are rare reports of bradycardia and hypothermia but not in the same patient. CASE REPORT A 4-year-old boy given intravenous azithromycin as part of treatment for febrile neutropenia complicating leukemia chemotherapy developed hypothermia (rectal temperature 35.2°C) and bradycardia (65 beats/minute) after the second dose, which resolved over several days post-treatment, consistent with persistence of high tissue azithromycin concentrations relative to those in plasma. A sigmoid Emax pharmacokinetic/pharmacodynamic model suggested a maximal azithromycin-associated reduction in heart rate of 23 beats/minute. Monitoring for these potential adverse effects should facilitate appropriate supportive care in similar cases. CONCLUSIONS Recommended azithromycin doses can cause at least moderate bradycardia and hypothermia in vulnerable pediatric patients, adverse effects that should prompt appropriate monitoring and which may take many days to resolve.

Takotsubo cardiomyopathy: A known unknown foe of asthma.

PubMed

Kotsiou, Ourania S; Douras, Alexandros; Makris, Demosthenes; Mpaka, Nikoleta; Gourgoulianis, Konstantinos I

2017-10-01

Patients with uncontrolled asthma are at a greater risk of asthma attacks requiring emergency room visits or hospital admissions. Takotsubo cardiomyopathy is potentially a significant complication in a course of status asthmaticus. We describe a 43-year-old female patient who presented with status asthmaticus that was further complicated with takotsubo cardiomyopathy. Recognizing apical ballooning syndrome is challenging in patients with a history of respiratory disease because the symptoms of the last entity may complicate the diagnostic approach. It is difficult to distinguish clinically apical ballooning syndrome from the acute airway exacerbation itself. Both asthma and takotsubo cardiomyopathy share the same clinical presentation with dyspnea and chest tightness. In our patient, the electrocardiographic abnormalities, the rapidly reversible distinctive characteristics of echocardiography, and the modest elevation of serum cardiac biomarkers levels, in combination with the presence of a stress trigger (severe asthma attack), strongly supported the diagnosis of broken heart syndrome. Clinicians should re-evaluate asthma management and be aware of the complications associated with asthma attacks such as stress-induced cardiomyopathy.

Enabling smart personalized healthcare: a hybrid mobile-cloud approach for ECG telemonitoring.

PubMed

Wang, Xiaoliang; Gui, Qiong; Liu, Bingwei; Jin, Zhanpeng; Chen, Yu

2014-05-01

The severe challenges of the skyrocketing healthcare expenditure and the fast aging population highlight the needs for innovative solutions supporting more accurate, affordable, flexible, and personalized medical diagnosis and treatment. Recent advances of mobile technologies have made mobile devices a promising tool to manage patients' own health status through services like telemedicine. However, the inherent limitations of mobile devices make them less effective in computation- or data-intensive tasks such as medical monitoring. In this study, we propose a new hybrid mobile-cloud computational solution to enable more effective personalized medical monitoring. To demonstrate the efficacy and efficiency of the proposed approach, we present a case study of mobile-cloud based electrocardiograph monitoring and analysis and develop a mobile-cloud prototype. The experimental results show that the proposed approach can significantly enhance the conventional mobile-based medical monitoring in terms of diagnostic accuracy, execution efficiency, and energy efficiency, and holds the potential in addressing future large-scale data analysis in personalized healthcare.

Forgetting heart break: a fascinating case of transient left ventricular apical ballooning syndrome associated with dissociative amnesia.

PubMed

Toussi, Amir; Bryk, Jodie; Alam, Abdulkader

2014-01-01

Transient left ventricular apical ballooning syndrome (TLVABS), also known as takotsubo cardiomyopathy, is characterized by transient left ventricular dysfunction, electrocardiographic changes, and release of myocardial enzymes that mimic acute myocardial infarction in patients without angiographic evidence of coronary artery disease. Most patients are post-menopausal women and an emotional or physiologic stressor frequently precedes the presentation. Psychogenic or dissociative amnesia is a memory disorder characterized by sudden retrograde memory loss with inability to recall personal information said to occur for a period of time ranging from hours to years after a stressful event. Interestingly, the mechanism of both disorders has been linked to plasma elevation in catecholamines. Here we present the case of a 66-year-old female diagnosed with both TLVABS and dissociative amnesia following the sudden unexpected death of her sister. To our knowledge, this is surprisingly the first report of the co-occurrence of TLVABS and dissociative amnesia, two processes with a potential shared underlying etiology. © 2013.

Synchronous acquisition of multi-channel signals by single-channel ADC based on square wave modulation

NASA Astrophysics Data System (ADS)

Yi, Xiaoqing; Hao, Liling; Jiang, Fangfang; Xu, Lisheng; Song, Shaoxiu; Li, Gang; Lin, Ling

2017-08-01

Synchronous acquisition of multi-channel biopotential signals, such as electrocardiograph (ECG) and electroencephalograph, has vital significance in health care and clinical diagnosis. In this paper, we proposed a new method which is using single channel ADC to acquire multi-channel biopotential signals modulated by square waves synchronously. In this method, a specific modulate and demodulate method has been investigated without complex signal processing schemes. For each channel, the sampling rate would not decline with the increase of the number of signal channels. More specifically, the signal-to-noise ratio of each channel is n times of the time-division method or an improvement of 3.01 ×log2n dB, where n represents the number of the signal channels. A numerical simulation shows the feasibility and validity of this method. Besides, a newly developed 8-lead ECG based on the new method has been introduced. These experiments illustrate that the method is practicable and thus is potential for low-cost medical monitors.

Assessment of tobacco smoke effects on neonatal cardiorespiratory control using a semi-automated processing approach.

PubMed

Al-Omar, Sally; Le Rolle, Virginie; Beuchée, Alain; Samson, Nathalie; Praud, Jean-Paul; Carrault, Guy

2018-05-10

A semi-automated processing approach was developed to assess the effects of early postnatal environmental tobacco smoke (ETS) on the cardiorespiratory control of newborn lambs. The system consists of several steps beginning with artifact rejection, followed by the selection of stationary segments, and ending with feature extraction. This approach was used in six lambs exposed to 20 cigarettes/day for the first 15 days of life, while another six control lambs were exposed to room air. On postnatal day 16, electrocardiograph and respiratory signals were obtained from a 6-h polysomnographic recording. The effects of postnatal ETS exposure on heart rate variability, respiratory rate variability, and cardiorespiratory interrelations were explored. The unique results suggest that early postnatal ETS exposure increases respiratory rate variability and decreases the coupling between cardiac and respiratory systems. Potentially harmful consequences in early life include unstable breathing and decreased adaptability of cardiorespiratory function, particularly during early life challenges, such as prematurity or viral infection. Graphical abstract ᅟ.

[Acute lithium poisoning: epidemiology, clinical characteristics, and treatment].

PubMed

Burguera Vion, Víctor; Montes, José Manuel; Del Rey, José Manuel; Rivera-Gorrín, Maite; Rodao, José María; Tenorio, Maite; Saiz-Ruiz, Jerónimo; Liaño, Fernando

2017-02-01

Lithium continues to be the treatment of choice for bipolar disorder. Acute lithium poisoning is a potentially serious event. We present a retrospective observational significative study of episodes of acute lithium poisoning during a 52- month period. Poisoning was defined by a blood lithium concentration of 1.5 mEq/L or higher. We analyzed treatment and epidemiologic and clinical characteristics of 70 episodes were identified (incidence density among treated patients, 1.76 per 100 patient-years). The most frequent cause of lithium poisoning was a concurrent medical condition (46%). Most poisonings were mild (74.2%), but neurologic involvement was identified in 40.3%. Electrocardiographic abnormalities were found in 8 cases. Acute renal failure, found in 23 patients (37.1%), was mild in most cases, although 11 patients required hemodialysis. We concluded that acute lithium poisoning is an uncommon complication, but risk needs to be lowered. Patients should be warned to avoid dosage errors and to take special care during concurrent illnesses and while taking other medications.

ELECTROCARDIOGRAPHIC CHANGES IN RABBITS SUBJECTED TO THE CHRONIC ACTION OF RADIOACTIVE ZINC DURING INTRAVENOUS ADMINISTRATION OF ADRENALINE AND INHALATION OF AMMONIA (in Russian)

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

Ovakimov, V.G.; Bibikhin, L.N.; Saitanov, A.O.

1963-09-01

The employment of pharmacological loadings (administration of adrenaline and inhalation of ammonia) in rabbits subjected to the chronic action of radioactive zinc (1 and 10 mu C/kg) disclosed changes in the sensitivity of adrenoreactive systems of the myocardium (in adrenaline test) and an altered intensity and duration of reflex bradycardia (in ammonia test). (auth)

Physiologic Status Monitoring via the Gastrointestinal Tract

DTIC Science & Technology

2015-11-18

1763-1773. 7. Deswysen AC, Zimerson E, Goossens A, Bruze M, Baeck M (2013) Allergic contact dermatitis caused by self-adhesive electrocardiography...electrodes in an infant. Contact dermatitis 69: 379-381. 8. Rafiei H, Amiri M, Moghaddasi J (2013) Skin irritation because of electrocardiograph lead...microphone, we measured acoustic data along the GI tract from the mouth to the colon. We evaluated the impact device contact with GI tissue and

Physiologic Status Monitoring via the Gastrointestinal Tract

DTIC Science & Technology

2015-11-18

7. Deswysen AC, Zimerson E, Goossens A, Bruze M, Baeck M (2013) Allergic contact dermatitis caused by self-adhesive electrocardiography electrodes...in an infant. Contact dermatitis 69: 379-381. 8. Rafiei H, Amiri M, Moghaddasi J (2013) Skin irritation because of electrocardiograph lead in...microphone, we measured acoustic data along the GI tract from the mouth to the colon. We evaluated the impact device contact with GI tissue and previously

Physiologic Status Monitoring via the Gastrointestinal Tract

DTIC Science & Technology

2016-02-25

7. Deswysen AC, Zimerson E, Goossens A, Bruze M, Baeck M (2013) Allergic contact dermatitis caused by self-adhesive electrocardiography electrodes...in an infant. Contact dermatitis 69: 379-381. 8. Rafiei H, Amiri M, Moghaddasi J (2013) Skin irritation because of electrocardiograph lead in...we measured acoustic data along the GI tract from the mouth to the colon. We evaluated the impact device contact with GI tissue and previously

The Effects of Physical Conditioning on Heat Tolerance in Chemical Defense Gear.

DTIC Science & Technology

1986-06-01

symptoms and electrocardiographic signs of impending or acute myocardial infarction and myocar- ditis and aortic stenosis 6. Acute infectious diseases...systolic blood pressure over 200 mm Hg 12. Electrolyte abnormalities 13. Any serious systemic disorder ( mononucleosis , hepatitis, etc.) 14...34Mechanisms of Acclimitization to Heat in Man.- M, 34: 323-380, 1955. Baxter, C.R. "Prevention, Recognition and Treatment of Heat Disorder." Texas State

Laser Atrial Septostomy: An Engineering Problem

NASA Astrophysics Data System (ADS)

Ben-Shachar, Giora; Cohen, Mark H.; Riemenschneider, Thomas A.; Beder, Stanley D.

1987-04-01

The purpose of this study was to develop a reproducible method for atrial septostomy in live animals, which would be independent of both atrial septal thickness and left atrial size. Seven mongrel dogs monitored electrocardiographically were anesthetized and instrumented with systemic and pulmonary arterial lines. A modified Mullin's transseptal sheath was advanced under fluoroscopic control to interrogate the left atrium and atrial septum. A 400 micron regular quartz or a laser heated metallic tip fiber was passed through the sheath up to the atrial septum. Lasing of the atrial septum was done with an Argon laser at power output of 5 watts. In three dogs, an atrial septosomy catheter was passed to the left atrium through the laser atrial septostomy and balloon atrial septostomy was performed. The laser atrial septostomy measured 3 x 5 mm in diameter. This interatrial communication could be enlarged with a balloon septostomy to over one cm in diameter. Hemodynamic and electrocardiographic monitoring were stable during the procedure. Engineering problems included: 1) radioluscency of the laser fibers thus preventing fluoroscopic localization of the fiber course; and 2) the inability to increase lateral vaporization of the atrial septum. It is concluded that further changes in the lasing fibers need to be made before the method can be considered for clinical use.

Incorrect electrode cable connection during electrocardiographic recording.

PubMed

Batchvarov, Velislav N; Malik, Marek; Camm, A John

2007-11-01

Incorrect electrode cable connections during electrocardiographic (ECG) recording can simulate rhythm or conduction disturbance, myocardial ischaemia and infarction, as well as other clinically important abnormalities. When only precordial or only limb cables, excluding the neutral cable, have been interchanged the waveforms in the different leads are re-arranged, inverted, or unchanged, whereas the duration of intervals is not changed. The mistake can be recognized by the presence of unusual P-QRS patterns (e.g. negative P-QRS in lead I or II, positive in lead AVR, P-QRS complexes of opposite direction in leads I and V6, etc.), change in the P-QRS axis, or abnormal precordial QRS-T wave progression. Interchange of limb cables with the neutral cable distorts Wilson's terminal and the morphology of all precordial and unipolar limb leads. The telltale sign of the mistake is the presence of (almost) a flat line in lead I, II or III. Interchange of even one of the limb cables, except for the neutral cable, with a precordial cable distorts the morphology of most leads and leaves not more than one lead (I, II, or III) unchanged. Computerized algorithms for detection of lead misplacement, such as those based on artificial neural networks, or on correlation between original and reconstructed leads, have been developed.

Modelling the heart as a communication system.

PubMed

Ashikaga, Hiroshi; Aguilar-Rodríguez, José; Gorsky, Shai; Lusczek, Elizabeth; Marquitti, Flávia Maria Darcie; Thompson, Brian; Wu, Degang; Garland, Joshua

2015-04-06

Electrical communication between cardiomyocytes can be perturbed during arrhythmia, but these perturbations are not captured by conventional electrocardiographic metrics. We developed a theoretical framework to quantify electrical communication using information theory metrics in two-dimensional cell lattice models of cardiac excitation propagation. The time series generated by each cell was coarse-grained to 1 when excited or 0 when resting. The Shannon entropy for each cell was calculated from the time series during four clinically important heart rhythms: normal heartbeat, anatomical reentry, spiral reentry and multiple reentry. We also used mutual information to perform spatial profiling of communication during these cardiac arrhythmias. We found that information sharing between cells was spatially heterogeneous. In addition, cardiac arrhythmia significantly impacted information sharing within the heart. Entropy localized the path of the drifting core of spiral reentry, which could be an optimal target of therapeutic ablation. We conclude that information theory metrics can quantitatively assess electrical communication among cardiomyocytes. The traditional concept of the heart as a functional syncytium sharing electrical information cannot predict altered entropy and information sharing during complex arrhythmia. Information theory metrics may find clinical application in the identification of rhythm-specific treatments which are currently unmet by traditional electrocardiographic techniques. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Quantitative computed tomography of pulmonary emphysema and ventricular function in chronic obstructive pulmonary disease patients with pulmonary hypertension.

PubMed

Huang, Yu-Sen; Hsu, Hsao-Hsun; Chen, Jo-Yu; Tai, Mei-Hwa; Jaw, Fu-Shan; Chang, Yeun-Chung

2014-01-01

This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT). Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators. Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume (R(2) = 0.340, p = 0.023), RV stroke volume (R(2) = 0.406, p = 0.011), and RV cardiac output (R(2) = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed. The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.

Increased intracranial pressure elicits hypertension, increased sympathetic activity, electrocardiographic abnormalities and myocardial damage in rats.

PubMed

Shanlin, R J; Sole, M J; Rahimifar, M; Tator, C H; Factor, S M

1988-09-01

Intracranial pressure was increased in 59 rats by inflating a subdural balloon to a total mass volume of 0.3 ml. The increase in intracranial pressure ranged from 75 to greater than 500 mm Hg. With few exceptions, mean arterial pressure increased to as high as 227 mm Hg during the increase in intracranial pressure. Significant increases in plasma catecholamines, major electrocardiographic changes and a considerably shortened survival time were observed only in the rats that demonstrated an increase in mean arterial pressure greater than 50 mm Hg. A perfusion study with liquid silicone rubber (Microfil) revealed dilated irregular myocardial vessels with areas of focal constriction consistent with microvascular spasm. Histologic examination of the myocardium revealed widespread patches of contraction band necrosis and occasional contraction bands in the smooth muscle media of large coronary arteries. These observations suggest that myocardial damage after suddenly increased intracranial pressure resulted both from exposure to toxic levels of catecholamines and from myocardial reperfusion. Extension of these studies to humans suggests that a detailed assessment of myocardial function should be performed in victims of severe brain injury. Myocardial dysfunction may be a major determinant of the patient's prognosis or may render the heart unsuitable for transplantation.

A brief review: history to understand fundamentals of electrocardiography

PubMed Central

AlGhatrif, Majd; Lindsay, Joseph

2012-01-01

The last decade of the 19th century witnessed the rise of a new era in which physicians used technology along with classical history taking and physical examination for the diagnosis of heart disease. The introduction of chest x-rays and the electrocardiograph (electrocardiogram) provided objective information about the structure and function of the heart. In the first half of the 20th century, a number of innovative individuals set in motion a fascinating sequence of discoveries and inventions that led to the 12-lead electrocardiogram, as we know it now. Electrocardiography, nowadays, is an essential part of the initial evaluation for patients presenting with cardiac complaints. As a first line diagnostic tool, health care providers at different levels of training and expertise frequently find it imperative to interpret electrocardiograms. It is likely that an understanding of the electrical basis of electrocardiograms would reduce the likelihood of error. An understanding of the disorders behind electrocardiographic phenomena could reduce the need for memorizing what may seem to be an endless list of patterns. In this article, we will review the important steps in the evolution of electrocardiogram. As is the case in most human endeavors, an understanding of history enables one to deal effectively with the present. PMID:23882360

Primary angioplasty for infarction due to isolated right ventricular artery occlusion.

PubMed

Chahal, Anwar A; Kim, Min-Young; Borg, Alexander N; Al-Najjar, Yahya

2014-11-26

We report an unusual case of an isolated right ventricular infarction with haemodynamic compromise caused by spontaneous isolated proximal occlusion of the right ventricular branch of the right coronary artery (RCA), successfully treated by balloon angioplasty. A 58-year-old gentleman presented with epigastric pain radiating into both arms. Electrocardiograph with right ventricular leads confirmed ST elevation in V4R and a diagnosis of isolated right ventricular infarction was made. Urgent primary percutaneous intervention was performed which revealed occlusion of the right ventricular branch of the RCA. During the procedure, the patient's blood pressure dropped to 80/40 mmHg, and echocardiography showed impaired right ventricular systolic function. Despite aggressive fluid resuscitation, the patient remained hypotensive, continued to have chest pain and persistent electrocardiograph changes, and hence balloon angioplasty was performed on the proximal right ventricular branch which restored flow to the vessel and revealed a severe ostial stenosis. This was treated with further balloon angioplasty which restored TIMI 3 flow with resolution of patient's symptoms. Repeat echocardiography showed complete resolution of the ST-elevation in leads V4R and V5R and partial resolution in V1. Subsequent dobutamine-stress echocardiography at 4 wk showed good left and right ventricular contractions. The patient was discharged after a 3-d in-patient stay without any complications.

Morbidity of Chagas heart disease in the microregion of Rio Negro, Amazonian Brazil: a case-control study

PubMed Central

Coura, José Rodrigues; Viñas, Pedro Albajar; Brum-Soares, Lucia Maria; de Sousa, Andréa Silvestre; Xavier, Sérgio Salles

2013-01-01

A case-control study on the morbidity of Chagas heart disease was carried out in the municipality of Barcelos in the microregion of the Rio Negro, state of Amazonas. One hundred and six individuals, who were serologically positive for Trypanosoma cruzi infection, as confirmed by at least two techniques with different principles, were matched according to age and sex with an equal number of seronegative individuals. The cases and controls were evaluated using an epidemiological questionnaire and clinical, electrocardiograph and echocardiograph examinations. In the seroepidemiological evaluation, 62% of the interviewees recognised triatomines and most of them confirmed that they had seen these insects in the piassava plantations of the riverside communities of the Negro River tributaries. Of the seropositive patients, 25.8% affirmed that they had been stung by the triatomines and 11.7% denied having been stung. The principal clinical manifestations of the seropositive individuals were palpitations, chest pain and dyspnoea upon effort. Cardiac auscultation revealed extrasystoles, bradycardia and systolic murmurs. The electrocardiographic alterations were ventricular extrasystoles, left and right bundle branch block, atrioventricular block and primary T wave alterations. The echocardiogram was altered in 22.6% of the seropositive individuals and in 8.5% of the seronegative individuals. PMID:24402153

A young patient with atypical type-B Wolff–Parkinson–White syndrome accompanied by left ventricular dysfunction

PubMed Central

Takeuchi, Takahiro; Tomita, Takeshi; Kasai, Hiroki; Kashiwagi, Daisuke; Yoshie, Koji; Yaguchi, Tomonori; Oguchi, Yasutaka; Kozuka, Ayako; Gautam, Milan; Motoki, Hirohiko; Okada, Ayako; Shiba, Yuji; Aizawa, Kazunori; Izawa, Atsushi; Miyashita, Yusuke; Koyama, Jun; Hongo, Minoru; Ikeda, Uichi

2014-01-01

A 15-year-old asymptomatic male patient presented with an electrocardiographic abnormality and left ventricular (LV) dysfunction (left ventricle ejection fraction of 40%) in a physical examination performed 2 years previously. LV dysfunction did not improve despite optimal medical therapy for dilated cardiomyopathy. Twelve-lead electrocardiography revealed a normal PR interval (138 ms) with a small delta-like wave in V2, but not a typical diagnostic wave that could be diagnosed as Wolff–Parkinson–White (WPW) syndrome by an electrocardiogram auto-analysis. Transthoracic echocardiography showed a remarkable asynchronous septal motion. An electrophysiological study was performed to exclude WPW syndrome. An accessory pathway (AP) was revealed on the lateral wall of the right ventricle, and radiofrequency catheter ablation was successfully performed to disconnect the AP. Thereafter, the dyssynchrony disappeared, and LV function improved. The intrinsic atrioventricular nodal conduction was very slow (A-H, 237 ms). The results of electrocardiogram auto-analysis could not be used to confirm the diagnosis of WPW syndrome because of the atypical delta wave. Conduction via the right lateral AP caused electrical dyssynchrony in the LV. This case suggests that atypical delta waves should be evaluated without depending on electrocardiographic auto-analyses in patients with LV dysfunction accompanied by dyssynchrony. PMID:26336525

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.

Cardiac Repolarization Changes in the Children with Breath-Holding Spells

PubMed Central

Amoozgar, Hamid; Saleh, Fazl; Farhani, Nahal; Rafiei, Mohammad; Inaloo, Soroor; Asadipooya, Ali-Akbar

2013-01-01

Objective Breath-holding spells are known as benign attacks, frequencies of which decrease by the development of the autonomic nervous system. The present study aims to compare the electrocardiographic repolarization in children with breath-holding spells. Methods In this study, QT dispersion, QTc dispersion, T peak to T end dispersion, and P wave dispersion of the twelve-lead surface electrocardiography of fifty children who had breath-holding spells were measured and compared with normal children from April 2011 to August 2012. Findings Forty-four (88%) patients had cyanotic spells, while 6 (12%) had pallid spells. QTc dispersion was increased in the patients with breath-holding spells (148.2±33.1) compared to the healthy children (132±27.3) and the difference was statically significant (P = 0.01). Meanwhile, no statistically significant differences were observed between the patients and the control subjects regarding the other parameters (P > 0.05). Conclusion QTc dispersion was significantly increased in the patients with breath-holding spells compared to normal children and this is a sign of cardiac repolarization abnormality as well as the increased risk of cardiac arrhythmia in patients with breath-holding spells. PMID:24910749

A multichannel decision-level fusion method for T wave alternans detection

NASA Astrophysics Data System (ADS)

Ye, Changrong; Zeng, Xiaoping; Li, Guojun; Shi, Chenyuan; Jian, Xin; Zhou, Xichuan

2017-09-01

Sudden cardiac death (SCD) is one of the most prominent causes of death among patients with cardiac diseases. Since ventricular arrhythmia is the main cause of SCD and it can be predicted by T wave alternans (TWA), the detection of TWA in the body-surface electrocardiograph (ECG) plays an important role in the prevention of SCD. But due to the multi-source nature of TWA, the nonlinear propagation through thorax, and the effects of the strong noises, the information from different channels is uncertain and competitive with each other. As a result, the single-channel decision is one-sided while the multichannel decision is difficult to reach a consensus on. In this paper, a novel multichannel decision-level fusion method based on the Dezert-Smarandache Theory is proposed to address this issue. Due to the redistribution mechanism for highly competitive information, higher detection accuracy and robustness are achieved. It also shows promise to low-cost instruments and portable applications by reducing demands for the synchronous sampling. Experiments on the real records from the Physikalisch-Technische Bundesanstalt diagnostic ECG database indicate that the performance of the proposed method improves by 12%-20% compared with the one-dimensional decision method based on the periodic component analysis.

Analysis of the temporal regression of the QRS widening induced by bupivacaine after Intralipid administration. Study in an experimental porcine model.

PubMed

Zaballos, M; Sevilla, R; González, J; Callejo, D; de Diego, C; Almendral, J; Quintela, O; Anadón, M J

2016-01-01

The principal mechanism of cardiac toxicity of bupivacaine relates to the blockade of myocardial sodium channels, which leads to an increase in the QRS duration. Recently, experimental studies suggest that lipid emulsion is effective in reversing bupivacaine cardiac toxicity. We aimed to evaluate the temporal evolution of the QRS widening induced by bupivacaine with the administration of Intralipid. Twelve pigs were anesthetized with intravenous sodium thiopental 5mg kg(-1) and sevoflurane 1 MAC (2.6%). Femoral artery and vein were canalized for invasive monitoring, analysis of blood gases and determination of bupivacaine levels. After instrumentation and monitoring, a bupivacaine bolus of 4-6 mg kg(-1) was administered in order to induce a 150% increase in QRS duration (defined as the toxic point). The pigs were randomized into two groups of six individuals. Intralipid group (IL) received 1.5 mL kg(-1)of IL over one minute, followed by an infusion of 0.25 mL kg min(-1). Control group (C) received the same volume of a saline solution. The electrocardiographic parameters were recorded, and blood samples were taken after bupivacaine and 1, 5, 10 and 30 minutes after Intralipid/saline administration. Bupivacaine (4.33±0.81 mg/kg in IL group and 4.66±1.15 mg/kg in C group) induced similar electrocardiographic changes in both groups; mean maximal percent increase in QRS interval was 184±62% in IL group, and 230±56% in control group (NS). Lipid administration reversed the QRS widening previously impaired by bupivacaine. After ten minutes of the administration of IL, the mean QRS interval decreased to 132±56% vs. 15±76% relative to the maximum widening induced by bupivacaine, in IL and C group, respectively. Intralipid reversed the lengthening of QRS interval induced by the injection of bupivacaine. Time to normalization of electrocardiographic parameters can last more than 10 minutes. While the phenomena of cardiac toxicity persist, resuscitation measures and adequate monitoring should be continued until adequate heart conduction parameters are restored. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Electrocardiologic and related methods of non-invasive detection and risk stratification in myocardial ischemia: state of the art and perspectives

PubMed Central

Huebner, Thomas; Goernig, Matthias; Schuepbach, Michael; Sanz, Ernst; Pilgram, Roland; Seeck, Andrea; Voss, Andreas

2010-01-01

Background: Electrocardiographic methods still provide the bulk of cardiovascular diagnostics. Cardiac ischemia is associated with typical alterations in cardiac biosignals that have to be measured, analyzed by mathematical algorithms and allegorized for further clinical diagnostics. The fast growing fields of biomedical engineering and applied sciences are intensely focused on generating new approaches to cardiac biosignal analysis for diagnosis and risk stratification in myocardial ischemia. Objectives: To present and review the state of the art in and new approaches to electrocardiologic methods for non-invasive detection and risk stratification in coronary artery disease (CAD) and myocardial ischemia; secondarily, to explore the future perspectives of these methods. Methods: In follow-up to the Expert Discussion at the 2008 Workshop on "Biosignal Analysis" of the German Society of Biomedical Engineering in Potsdam, Germany, we comprehensively searched the pertinent literature and databases and compiled the results into this review. Then, we categorized the state-of-the-art methods and selected new approaches based on their applications in detection and risk stratification of myocardial ischemia. Finally, we compared the pros and cons of the methods and explored their future potentials for cardiology. Results: Resting ECG, particularly suited for detecting ST-elevation myocardial infarctions, and exercise ECG, for the diagnosis of stable CAD, are state-of-the-art methods. New exercise-free methods for detecting stable CAD include cardiogoniometry (CGM); methods for detecting acute coronary syndrome without ST elevation are Body Surface Potential Mapping, functional imaging and CGM. Heart rate variability and blood pressure variability analyses, microvolt T-wave alternans and signal-averaged ECG mainly serve in detecting and stratifying the risk for lethal arrythmias in patients with myocardial ischemia or previous myocardial infarctions. Telemedicine and ambient-assisted living support the electrocardiological monitoring of at-risk patients. Conclusions: There are many promising methods for the exercise-free, non-invasive detection of CAD and myocardial ischemia in the stable and acute phases. In the coming years, these new methods will help enhance state-of-the-art procedures in routine diagnostics. The future can expect that equally novel methods for risk stratification and telemedicine will transition into clinical routine. PMID:21063467

Electrocardiographic recognition of right ventricular hypertrophy.

PubMed

Nikus, Kjell; Pérez-Riera, Andrés Ricardo; Konttila, Kaari; Barbosa-Barros, Raimundo

The electrocardiogram (ECG) is a relatively insensitive tool for the detection of right ventricular hypertrophy (RVH), but some criteria have high specificity. The recommended ECG screening criteria for RVH are not sufficiently sensitive or specific for screening for mild RVH in adults without clinical cardiovascular disease. The greatest accuracy of the ECG is in congenital heart disease, with intermediate accuracy in acquired heart disease and primary pulmonary hypertension in adults. Copyright © 2017 Elsevier Inc. All rights reserved.

Construction of a Resting High Fidelity ECG "SuperScore" for Management and Screening of Heart Disease

NASA Technical Reports Server (NTRS)

Schlegel, Todd T.; Delgado, Reynolds; Poulin, Greg; Starc, Vito; Arenare, Brian; Rahman, M. A.

2006-01-01

Resting conventional ECG is notoriously insensitive for detecting coronary artery disease (CAD) and only nominally useful in screening for cardiomyopathy (CM). Similarly, conventional exercise stress test ECG is both time- and labor-consuming and its accuracy in identifying CAD is suboptimal for use in population screening. We retrospectively investigated the accuracy of several advanced resting electrocardiographic (ECG) parameters, both alone and in combination, for detecting CAD and cardiomyopathy (CM).

ST-segment monitoring: putting standards into practice.

PubMed

Flanders, Sonya A

2007-01-01

ST-segment monitoring is one key reason that continuous electrocardiographic monitoring is performed in hospitals, and can help with early detection of myocardial ischemia for at-risk patients. Although ST-segment monitoring research, guidelines, and expert consensus statements have been published, ST-segment monitoring has not been implemented in all appropriate clinical areas. The purpose of this article is to present relevant research, review the latest practice standards, and discuss issues important to nurses wishing to implement ST-segment monitoring.

Biomedical technology transfer applications of NASA science and technology

NASA Technical Reports Server (NTRS)

1972-01-01

The identification and solution of research and clinical problems in cardiovascular medicine which were investigated by means of biomedical data transfer are reported. The following are sample areas that were focused upon by the Stanford University Biomedical Technology Transfer Team: electrodes for hemiplegia research; vectorcardiogram computer analysis; respiration and phonation electrodes; radiotelemetry of intracranial pressure; and audiotransformation of the electrocardiographic signal. It is concluded that this biomedical technology transfer is significantly aiding present research in cardiovascular medicine.

Evaluation of a New Shirt-Based Electrocardiogram Device for Cardiac Screening in Soccer Players: Comparative Study With Treadmill Ergospirometry.

PubMed

Fabregat-Andres, Oscar; Munoz-Macho, Adolfo; Adell-Beltran, Guillermo; Ibanez-Catala, Xavier; Macia, Agustin; Facila, Lorenzo

2014-08-01

Prevention of cardiac events during competitive sports is fundamental. New technologies with remote monitoring systems integrated into clothing could facilitate the screening of heart disease. Our aim was to evaluate the feasibility of Nuubo system during a field stress test performed by soccer players, comparing results with treadmill ergospirometry as test reference. Nineteen male professional soccer players (19.2 ± 1.6 years) were studied. Wireless electrocardiographic monitoring during a Yo-Yo intermittent recovery test level 1 in soccer field and subsequent analysis of arrhythmias were firstly performed. Subsequently, in a period no longer than 4 weeks, each player underwent cardiopulmonary exercise testing in hospital. During Yo-Yo test, electrocardiogram (ECG) signal was interpretable in 16 players (84.2%). In the other three players, ECG artifacts did not allow a proper analysis. Estimation of maximum oxygen consumption was comparable between two exercise tests (VO 2 max 53.3 ± 2.4 vs. 53.7 ± 3.0 mL/kg/min for Yo-Yo test and ergometry respectively; intra-class correlation coefficient 0.84 (0.63 - 0.93), P < 0.001). No arrhythmias were detected in any player during both tests. The use of Nuubo's technology allows an accurate single-lead electrocardiographic recording and estimation of reliable performance variables during exercise testing in field, and provides a new perspective to cardiac remote monitoring in collective sports.

Early electrocardiographic abnormalities in Trypanosoma cruzi-seropositive children.

PubMed

de Andrade, A L; Zicker, F; Rassi, A; Rassi, A G; Oliveira, R M; Silva, S A; de Andrade, S S; Martelli, C M

1998-10-01

As part of a major epidemiologic study on Chagas' disease, we compared the prevalence of electrocardiographic (ECG) abnormalities among 141 school children 7-12 years of age and seropositive for Trypanosoma cruzi, and 282 age-, sex-, and school-matched seronegative children in an endemic area in Brazil. The prevalence of ECG abnormalities was 11.3% among seropositive children and 3.5% among seronegative children (odds ratio = 3.5, 95% confidence interval [CI] = 1.5-8.4). The prevalence rate of ECG alterations was 10.7% for seropositive males versus 8.9% for seropositive females. Complete right bundle branch block (CRBBB), which is highly suggestive of Chagas' disease cardiopathy, was diagnosed in nine (6.4%) seropositive children and in only one (0.3%) seronegative child (odds ratio = 18.5, 95% CI = 2.3-146.5, attributable fraction = 58.3%). Five incident new cases of CRBBB were diagnosed after a 36-month follow-up of seropositive children who were enrolled in an independent clinical field trial. No case of frequent and/or multifocal ventricular premature beats was found in the cohort of children. The surprisingly high frequency of early ECG abnormalities, which indicates a rapid evolution from infection to disease, suggests the existence of endemic areas with a particular accelerated disease progression that was not described before. Under such conditions, a public health chemotherapy program focusing on the treatment of young seropositive children would be recommended.

Heart failure complicating myocardial infarction. A report of the Peruvian Registry of ST-elevation myocardial infarction (PERSTEMI).

PubMed

Chacón-Diaz, Manuel; Araoz-Tarco, Ofelia; Alarco-León, Walter; Aguirre-Zurita, Oscar; Rosales-Vidal, Maritza; Rebaza-Miyasato, Patricia

2018-05-01

The aim of this study is to determine the incidence, associated factors, and 30-day mortality of patients with heart failure (HF) after ST elevation myocardial infarction (STEMI) in Peru. Observational, cohort, multicentre study was conducted at the national level on patients enrolled in the Peruvian registry of STEMI, excluding patients with a history of HF. A comparison was made with the epidemiological characteristics, treatment, and 30 day-outcome of patients with (Group 1) and without (Group 2) heart failure after infarction. Of the 388 patients studied, 48.7% had symptoms of HF, or a left ventricular ejection fraction <40% after infarction (Group 1). Age>75 years, anterior wall infarction, and the absence of electrocardiographic signs of reperfusion were the factors related to a higher incidence of HF. The hospital mortality in Group 1 was 20.6%, and the independent factors related to higher mortality were age>75 years, and the absence of electrocardiographic signs of reperfusion. Heart failure complicates almost 50% of patients with STEMI, and is associated with higher hospital and 30-day mortality. Age greater than 75 years and the absence of negative T waves in the post-reperfusion ECG are independent factors for a higher incidence of HF and 30-day mortality. Copyright © 2018 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Noise and cardiovascular effects in workers of the sanitary fixtures industry.

PubMed

Assunta, Capozzella; Ilaria, Samperi; Simone, De Sio; Gianfranco, Tomei; Teodorico, Casale; Carmina, Sacco; Anastasia, Suppi; Roberto, Giubilati; Francesco, Tomei; Valeria, Rosati Maria

2015-01-01

The aim of the present study is to evaluate whether workers in the sanitary fixtures industry are a category at risk of developing cardiovascular diseases, and in particular, whether chronic noise exposure may play a role in cardiovascular effects in exposed workers. Seventy-five employees engaged in sanitation fixtures production and a control group of sixty-four office workers, who were not exposed to agents that could damage the cardiovascular system, participated in our study. The selected workers completed a clinical-anamnestic questionnaire, and underwent a medical examination, blood pressure test, electrocardiogram (ECG), blood tests, and audiometry. Measurements of environmental noise, dust, and lead were also carried out. The exposed workers, in comparison to the control group, showed a higher frequency of hypertension, systolic and diastolic blood pressure (p<0.05, p<0.05), as well as electrocardiographic abnormalities (p<0.05). There was also a higher frequency of hypertension and electrocardiographic abnormalities among subjects with audiometric deficit compared to normoacoustic subjects (p<0.05 and p<0.05). from our study suggest that work activity in the sanitary fixtures industry can have an influence on the cardiovascular system, and noise can be the main cause of damage for the cardiovascular system in exposed workers, as cardiovascular damage seems to be linked to hearing loss. Copyright © 2014 Elsevier GmbH. All rights reserved.

Safety and tolerability of adjunctive rosiglitazone treatment for children with uncomplicated malaria.

PubMed

Varo, Rosauro; Crowley, Valerie M; Sitoe, Antonio; Madrid, Lola; Serghides, Lena; Bila, Rubao; Mucavele, Helio; Mayor, Alfredo; Bassat, Quique; Kain, Kevin C

2017-05-23

Despite the widespread use and availability of rapidly acting anti-malarials, the fatality rate of severe malaria in sub-Saharan Africa remains high. Adjunctive therapies that target the host response to malaria infection may further decrease mortality over that of anti-malarial agents alone. Peroxisome proliferator-activated receptor-gamma agonists (e.g. rosiglitazone) have been shown to act on several pathways implicated in the pathogenesis of severe malaria and may improve clinical outcome as an adjunctive intervention. In this study, the safety and tolerability of adjunctive rosiglitazone in paediatric uncomplicated malaria infection was evaluated in Mozambique, as a prelude to its evaluation in a randomized controlled trial in paediatric severe malaria. The study was a prospective, randomized, double-blind, placebo-controlled, phase IIa trial of rosiglitazone (0.045 mg/kg/dose) twice daily for 4 days versus placebo as adjunctive treatment in addition to Mozambican standard of care (artemisinin combination therapy Coartem ® ) in children with uncomplicated malaria. The primary outcomes were tolerability and safety, including clinical, haematological, biochemical, and electrocardiographic evaluations. Thirty children were enrolled: 20 were assigned to rosiglitazone and 10 to placebo. Rosiglitazone treatment did not induce hypoglycaemia nor significantly alter clinical, biochemical, haematological, or electrocardiographic parameters. Adjunctive rosiglitazone was safe and well-tolerated in children with uncomplicated malaria, permitting the extension of its evaluation as adjunctive therapy for severe malaria. The trial is registered with Clinicaltrials.gov, NCT02694874.

Takotsubo Myocardiopathy and Hyperthyroidism: A Case Report and Literature Review.

PubMed

Rueda, Darío; Aguirre, Rafael; Contardo, Damián; Finocchietto, Paola; Hernandez, Silvia; di Fonzo, Horacio

2017-08-07

BACKGROUND Takotsubo cardiomyopathy (TM), also called stress myocardiopathy or transient left ventricular apical ballooning syndrome, is characterized by acute left ventricular dysfunction with reversible wall motion abnormalities. TM resembles acute coronary syndrome (ACS) in the absence of coronary artery disease (CAD). In several reports, TM has been described in association with hyperthyroidism, suggesting the potential role of thyrotoxicosis in the pathophysiology. CASE REPORT We present the case of a 34-year-old man with TM associated with hyperthyroidism caused by Graves' disease. In this case, TM was also preceded by an emotional trigger. The diagnosis of TM was based on clinical manifestations, electrocardiographic and echocardiographic abnormalities, and the absence of coronary artery disease (CAD) in the angiography. A diagnosis of hyperthyroidism was made based on hormonal and antibody measurements. The patient had a favorable outcome, and the cardiac and thyroid disorders resolved. CONCLUSIONS Our case illustrates that thyroid disease, mainly hyperthyroidism, should be considered in patients with TM with or without previous emotional triggers. As in our patient, the outcome in TM is usually favorable, with reversibility of cardiac abnormalities.

Cardiovascular applications of magnetic resonance imaging

PubMed Central

Pflugfelder, Peter W.; Wisenberg, Gerald; Prato, Frank S.

1985-01-01

Magnetic resonance (MR) imaging is a unique imaging modality that is gaining rapid acceptance for a variety of medical indications. Diagnostic information is obtained noninvasively, without the potential hazards of ionizing radiation. The spatial resolution and anatomic detail of MR imaging rival those of other currently available imaging methods. By gating to an electrocardiographic signal cardiac imaging is possible. Since March 1983 the authors have had experience with cardiac MR imaging in both animals and humans. Cardiac anatomy is well shown by this technique, which allows detection and characterization of intracardiac masses, congenital heart disease and anomalies of the great vessels. Myocardial infarction has been detected in both animals and humans without the use of contrast agents, and acute cardiac transplant rejection has been visualized in an animal model. Limitations of MR imaging primarily have been lengthy imaging times and the sensitivity of the images to motion. With further investigation and experience this technique may become useful for studying a wide variety of cardiovascular disorders. ImagesFig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:3904969

Antidiabetic activity of mefloquine via GLP-1 receptor modulation against STZ-NA-induced diabetes in albino wistar rats.

PubMed

Yadav, Rajnish Kumar; Rawat, Jitendra K; Gautam, Swetlana; Singh, Manjari; Kumar, Manish; Ansari, Mohd Nazam; Roy, Subhadeep; Saeedan, Abdulaziz S; Kaithwas, Gaurav

2018-05-01

Mefloquine was retrieved as a glucagon -like peptide-1 receptor agonist and, therefore, evaluated for its antidiabetic potential against non-insulin-dependent diabetes mellitus (NIDDM) in experimental animals. NIDDM was induced by single intraperitoneal injection of streptozotocin and nicotinamide (60 + 110 mg/kg) in albino wistar rats. The experimental animals were scrutinised for electrocardiographic (ECG) and heart rate variability (HRV) factors to study the autonomic dysfunction along with blood glucose, serum insulin, and liver glycogen levels for glycemic control. Simultaneously, antioxidant markers (TBARs, protein carbonyl, GSH, SOD, catalase) and inflammatory markers (COX, LOX, NO) were scrutinized as well. Oral administration of mefloquine normalised the heart rate with favourable regulation of time and frequency domain HRV parameters. Mefloquine restored the blood glucose, serum insulin, and liver glycogen levels favourably in diabetic rats. Treatment with mefloquine curtailed the antioxidant markers with favourable regulation of inflammatory signals. Mefloquine was also found to be less hepatotoxic in contrast to the standard metformin, providing an integrated advantage as an antidiabetic agent.

Withholding and termination of resuscitation of adult cardiopulmonary arrest secondary to trauma: resource document to the joint NAEMSP-ACSCOT position statements.

PubMed

Millin, Michael G; Galvagno, Samuel M; Khandker, Samiur R; Malki, Alisa; Bulger, Eileen M

2013-09-01

In the setting of traumatic cardiopulmonary arrest, protocols that direct emergency medical service (EMS) providers to withhold or terminate resuscitation, when clinically indicated, have the potential to decrease unnecessary use of warning lights and sirens and save valuable public health resources. Protocols to withhold resuscitation should be based on the determination that there are no obvious signs of life, the injuries are obviously incompatible with life, there is evidence of prolonged arrest, and there is a lack of organized electrocardiographic activity. Termination of resuscitation is indicated when there are no signs of life and no return of spontaneous circulation despite appropriate field EMS treatment that includes minimally interrupted cardiopulmonary resuscitation. Further research is needed to determine the appropriate duration of cardiopulmonary resuscitation before termination of resuscitation and the proper role of direct medical oversight in termination of resuscitation protocols. This article is the resource document to the position statements, jointly endorsed by the National Association of EMS Physicians and the American College of Surgeons' Committee on Trauma, on withholding and termination of resuscitation in traumatic cardiopulmonary arrest.

The initial electrocardiogram during admission for myocardial infarction. Use as a predictor of clinical course and facility utilization.

PubMed

Stark, M E; Vacek, J L

1987-05-01

The first electrocardiogram obtained on presentation for suspected myocardial infarction was examined for its usefulness in predicting clinical course and facility use. We studied 221 patients consecutively admitted to a nonuniversity hospital coronary care unit. High-risk patients were identified if the electrocardiographic diagnoses included myocardial infarction, ischemia, left ventricular hypertrophy, left bundle-branch block, or paced rhythm. These 63 patients (29% of total) had significantly greater incidences of serious events, need for procedures, and death than low-risk patients whose initial electrocardiograms did not carry the above diagnoses. Patients with a low-risk initial electrocardiogram may not require the facilities of a coronary care unit and perhaps could be safely observed in an intermediate care area. However, many hospitals do not have an intermediate care facility available, and in those that do, daily costs may not be markedly different than for treatment in a coronary care unit. Whether these low-risk patients could be safely treated in general medicine beds, where potential cost savings would be much greater, is unknown.

Hyperkalaemia in patients in hospital.

PubMed Central

Paice, B; Gray, J M; McBride, D; Donnelly, T; Lawson, D H

1983-01-01

Significant hyperkalaemia occurred in 406 out of 29 063 patients admitted to a major Scottish teaching hospital in one year (1.4%). Mortality was higher in these patients than in control patients and was strongly correlated with the severity of the hyperkalaemia. Overall seven deaths were directly due to hyperkalaemia (out of 58 deaths among patients with hyperkalaemia). Factors contributing to a poor prognosis were severity and speed of onset of hyperkalaemia and the presence of appreciable renal impairment. Patients with hyperkalaemia were older and more likely to be male; this trend was present in all diagnostic subcategories. Genitourinary disease, gastrointestinal disease, and cancer were significantly more common among the patients with hyperkalaemia than the controls. Hyperkalaemia due to drug treatment was invariably mild and non-fatal, whereas genitourinary disease was often associated with moderate to severe hyperkalaemia, which in two cases proved fatal. Use of electrocardiographic monitoring was rare, and although the treatment of hyperkalaemia was effective, it was often used when not required. Hyperkalaemia is a potential hazard in diabetic ketoacidosis, and use of potassium supplements should be carefully monitored during correction of the acidosis. PMID:6404388

Takotsubo cardiomyopathy: an overlooked cause of chest pain

PubMed Central

Tomazelli, Bruno; Furieri, Natassia Prates; Coelho, Renato Alves; de Lima, Camila Fiorese

2014-01-01

Takotsubo cardiomyopathy (TTC), also known as apical ballooning syndrome, broken heart syndrome, or stress-induced cardiomyopathy, is defined as a transient disturbance of the left ventricle, which is quite often associated with electrocardiographic abnormalities that may mimic acute myocardial infarction. The syndrome is also characterized by a mild alteration of cardiac biomarkers in absence of coronary blood flow obstruction on the coronariography. Clinical presentation is often manifested by angina, dyspnea, syncope, and arrhythmias. Peculiarly, the left ventricle takes the form of “tako-tsubo” (a Japanese word for “octopus trap”) on the imaging workup. The authors report the case of a post-menopausal, hypertensive, dyslipidemic and type-II diabetic woman admitted at the emergency service with acute chest pain post physical exertion. Electrocardiogram showed signs of ischemia and myocardial necrosis markers were mildly increased. Echocardiography and ventriculography showed apical and mid-ventricular akinesia, with mild atherosclerotic coronary lesions. Thus diagnostic workup and the outcome followed the diagnostic criteria for TTC. The authors called attention to the potential of overlooking this diagnosis, since this syndrome is still not widely recognized. PMID:28580329

[The Brugada Syndrome in a Teenager].

PubMed

Miklashevich, I M; Kuleshova, E V; Termosesov, S A; Shkolnikova, M A

2017-02-01

The Brugada syndrome (BS) belongs to the group of hereditary channelopathies associated with elevated risk of sudden death (SD) in the absence of structural heart diseases. The disorder phenotypically manifests by specific electrocardiographic pattern, associated with ventricular tachycardia (VT). VT can be accompanied by loss of conscience, and after transformation to ventricular fibrillation result in SD. BS is extremely rare among children and adolescents. We present here a clinical case of teenager (age 17 years) with BS manifested by syncopal state at the background of fever.

Skin-electrode impedance measurement during ECG acquisition: method’s validation

NASA Astrophysics Data System (ADS)

Casal, Leonardo; La Mura, Guillermo

2016-04-01

Skm-electrode impedance measurement can provide valuable information prior. dunng and post electrocardiographic (ECG) or electroencephalographs (EEG) acquisitions. In this work we validate a method for skm-electrode impedance measurement using test circuits with known resistance and capacitor values, at different frequencies for injected excitation current. Finally the method is successfully used for impedance measurement during ECG acquisition on a subject usmg 125 Hz and 6 nA square wave excitation signal at instrumentation amplifier mput. The method can be used for many electrodes configuration.

Congenital aortic stenosis: follow-up of surgical management

PubMed Central

Bertranou, Enrique; Davignon, André; Chartrand, Claude; Kratz, Christa; Stanley, Paul

1971-01-01

We have reviewed the cases operated upon for correction of congenital aortic stenosis at l'Hôpital Ste-Justine between 1959 and 1969. Twenty-five of the 26 patients were readmitted for complete clinical, radiological and hemodynamic investigation. Fourteen had a valvular stenosis, eight a diaphragmatic subvalvular lesion, and three had mixed lesions. The results lead us to believe that the surgical treatment of this malformation is justified. The indications for surgery must take into account all available clinical, radiological, electrocardiographic and hemodynamic data. PMID:4107480

An overview of contemporary nuclear cardiology.

PubMed

Lewin, Howard C; Sciammarella, Maria G; Watters, Thomas A; Alexander, Herbert G

2004-01-01

Myocardial perfusion single photon emission computed tomography (SPECT) is a widely utilized noninvasive imaging modality for the diagnosis, prognosis, and risk stratification of coronary artery disease. It is clearly superior to the traditional planar technique in terms of imaging contrast and consequent diagnostic and prognostic yield. The strength of SPECT images is largely derived from the three-dimensional, volumetric nature of its image. Thus, this modality permits three-dimensional assessment and quantitation of the perfused myocardium and functional assessment through electrocardiographic gating of the perfusion images.

Evaluation of 5 Hour Energy Drink on the Blood Pressure and Electrocardiograph Parameters on Young Healthy Volunteers: A Randomized, Double Blind, Crossover, Placebo-Controlled Trial

DTIC Science & Technology

2014-02-11

Travis AFB CA INSTITUTIONAL REVIEW BOARD (IRB) ()~\\) Non-Exempt Study Final Report p3YVJ (Please 1J!J!£ all information. Use additional pages if...QTc interval after acute and chronic consumption. METHODS: This was a randomized, placebo controlled, crossover study enrolling young healthy volunteers...not on any medications. Subjects received the study drink (5 Hour Energy shot or placebo) twice daily separated by approximately 7 hours for the

[Electrocardiographic interpretation in athletes : 2017 recommendations for non-cardiologists].

PubMed

Meyer, Philippe; Gabus, Vincent

2017-07-12

A resting electrocardiogram (ECG) is recommended for screening of sudden cardiac death in young athletes. However, ECG interpretation in athletes requires an adequate training because normal physiological training adaptations in athletes can sometimes be hardly distinguished from abnormal findings suggestive of underlying pathology. In 2017, a consensus of international experts established new recommendations for a clear and accurate interpretation of ECGs in athletes. This article aims to guide non-cardiologists according to these new data, allowing a better triage of anomalies requiring further investigations.

ICare-ACS (Improving Care Processes for Patients With Suspected Acute Coronary Syndrome): A Study of Cross-System Implementation of a National Clinical Pathway.

PubMed

Than, Martin P; Pickering, John W; Dryden, Jeremy M; Lord, Sally J; Aitken, S Andrew; Aldous, Sally J; Allan, Kate E; Ardagh, Michael W; Bonning, John W N; Callender, Rosie; Chapman, Laura R E; Christiansen, Jonathan P; Cromhout, Andre P J; Cullen, Louise; Deely, Joanne M; Devlin, Gerard P; Ferrier, Katherine A; Florkowski, Christopher M; Frampton, Christopher M A; George, Peter M; Hamilton, Gregory J; Jaffe, Allan S; Kerr, Andrew J; Larkin, G Luke; Makower, Richard M; Matthews, Timothy J E; Parsonage, William A; Peacock, W Frank; Peckler, Bradley F; van Pelt, Niels C; Poynton, Louise; Richards, A Mark; Scott, Anthony G; Simmonds, Mark B; Smyth, David; Thomas, Oliver P; To, Andrew C Y; Du Toit, Stephen A; Troughton, Richard W; Yates, Kim M

2018-01-23

Efforts to safely reduce length of stay for emergency department patients with symptoms suggestive of acute coronary syndrome (ACS) have had mixed success. Few system-wide efforts affecting multiple hospital emergency departments have ever been evaluated. We evaluated the effectiveness of a nationwide implementation of clinical pathways for potential ACS in disparate hospitals. This was a multicenter pragmatic stepped-wedge before-and-after trial in 7 New Zealand acute care hospitals with 31 332 patients investigated for suspected ACS with serial troponin measurements. The implementation was a clinical pathway for the assessment of patients with suspected ACS that included a clinical pathway document in paper or electronic format, structured risk stratification, specified time points for electrocardiographic and serial troponin testing within 3 hours of arrival, and directions for combining risk stratification and electrocardiographic and troponin testing in an accelerated diagnostic protocol. Implementation was monitored for >4 months and compared with usual care over the preceding 6 months. The main outcome measure was the odds of discharge within 6 hours of presentation RESULTS: There were 11 529 participants in the preimplementation phase (range, 284-3465) and 19 803 in the postimplementation phase (range, 395-5039). Overall, the mean 6-hour discharge rate increased from 8.3% (range, 2.7%-37.7%) to 18.4% (6.8%-43.8%). The odds of being discharged within 6 hours increased after clinical pathway implementation. The odds ratio was 2.4 (95% confidence interval, 2.3-2.6). In patients without ACS, the median length of hospital stays decreased by 2.9 hours (95% confidence interval, 2.4-3.4). For patients discharged within 6 hours, there was no change in 30-day major adverse cardiac event rates (0.52% versus 0.44%; P =0.96). In these patients, no adverse event occurred when clinical pathways were correctly followed. Implementation of clinical pathways for suspected ACS reduced the length of stay and increased the proportions of patients safely discharged within 6 hours. URL: https://www.anzctr.org.au/ (Australian and New Zealand Clinical Trials Registry). Unique identifier: ACTRN12617000381381. © 2017 American Heart Association, Inc.

Atrial conduction times and left atrial mechanical functions and their relation with diastolic function in prediabetic patients.

PubMed

Gudul, Naile Eris; Karabag, Turgut; Sayin, Muhammet Rasit; Bayraktaroglu, Taner; Aydin, Mustafa

2017-03-01

The aim of this study was to investigate atrial conduction times and left atrial mechanical functions, the noninvasive predictors of atrial fibrillation, in prediabetic patients with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Study included 59 patients (23 males, 36 females; mean age 52.5 ± 10.6 years) diagnosed with IFG or IGT by the American Diabetes Association criteria, and 43 healthy adults (22 males, 21 females; mean age 48.5 ± 12.1 years). Conventional and tissue Doppler echocardiography were performed. The electromechanical delay parameters were measured from the onset of the P wave on the surface electrocardiogram to the onset of the atrial systolic wave on tissue Doppler imaging from septum, lateral, and right ventricular annuli. The left atrial volumes were calculated by the disk method. Left atrial mechanical functions were calculated. The mitral E/A and E'/A' ratios measured from the lateral and septal annuli were significantly lower in the prediabetics compared to the controls. The interatrial and left atrial electromechanical delay were significantly longer in prediabetic group compared to the controls. Left atrial active emptying volume (LAAEV) and fraction (LAAEF) were significantly higher in the prediabetics than the controls. LAAEV and LAAEF were significantly correlated with E/A, lateral and septal E'/A'. In the prediabetic patients, the atrial conduction times and P wave dispersion on surface electrocardiographic were longer before the development of overt diabetes. In addition, the left atrial mechanical functions were impaired secondary to a deterioration in the diastolic functions in the prediabetic patients.

Acute effects of Red Bull energy drink on ventricular repolarization in healthy young volunteers: a prospective study

PubMed Central

Elitok, Ali; Öz, Fahrettin; Panc, Cafer; Sarıkaya, Remzi; Sezikli, Selim; Pala, Yasin; Bugan, Övgü Sinem; Ateş, Müge; Parıldar, Hilal; Ayaz, Mustafa Buğra; Atıcı, Adem; Oflaz, Hüseyin

2016-01-01

Objective: Energy drinks (EDs) are widely consumed products of the beverage industry and are often chosen by teenagers and young adults. Several adverse cardiovascular events and malignant cardiac arrhythmias following consumption of EDs have been reported in the literature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the dispersion of repolarization and that an increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. This study investigated the acute effects of Red Bull ED on ventricular repolarization as assessed by the Tp-e interval and Tp-e/QT ratio. Methods: A prospective, open-label study design was used. After an 8-h fast, 50 young, healthy subjects consumed 355 mL of Red Bull ED. The Tp-e interval, Tp-e/QTc ratio, and several other electrocardiographic parameters were measured at baseline and 2 h after ingestion of Red Bull ED. Results: No significant changes in the Tp-e interval or Tp-e/QTc ratio were observed with Red Bull ED consumption. Red Bull ED consumption led to increases in both systolic and diastolic blood pressures, which were associated with an increased heart rate. Conclusion: Although ingestion of Red Bull ED increases the heart rate and diastolic and systolic blood pressures, it does not cause alterations in ventricular repolarization as assessed by the Tp-e interval and Tp-e/QTc ratio. PMID:25868042

Clinical, Electrocardiographic, and Echocardiographic Parameter Combination Predicts the Onset of Atrial Fibrillation.

PubMed

Soeki, Takeshi; Matsuura, Tomomi; Tobiume, Takeshi; Bando, Sachiko; Matsumoto, Kazuhisa; Nagano, Hiromi; Uematsu, Etsuko; Kusunose, Kenya; Ise, Takayuki; Yamaguchi, Koji; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Wakatsuki, Tetsuzo; Shimabukuro, Michio; Sata, Masataka

2018-05-30

The ability to identify risk markers for new-onset atrial fibrillation (AF) is critical to the development of preventive strategies, but it remains unknown whether a combination of clinical, electrocardiographic, and echocardiographic parameters predicts the onset of AF. In the present study, we evaluated the predictive value of a combined score that includes these parameters.Methods and Results:We retrospectively studied 1,040 patients without AF who underwent both echocardiography and 24-h Holter electrocardiography between May 2005 and December 2010. During a median follow-up period of 68.4 months (IQR, 49.9-93.3 months), we investigated the incidence of new-onset AF. Of the 1,040 patients, 103 (9.9%) developed AF. Patients who developed AF were older than patients who did not. Total heart beats, premature atrial contraction (PAC) count, maximum RR interval, and frequency of sinus pause quantified on 24-h electrocardiography were associated with new-onset AF. LA diameter (LAD) on echocardiography was also associated with the development of AF. On multivariate Cox analysis, age ≥58 years, PAC count ≥80 beats/day, maximum RR interval ≥1.64 s, and LAD ≥4.5 cm were independently associated with the development of AF. The incidence rate of new-onset AF significantly increased as the combined score (i.e., the sum of the risk score determined using hazard ratios) increased. A combined score that includes age, PAC count, maximum RR interval, and LAD could help characterize the risk of new-onset AF.

Lack of effect of drinking water barium on cardiovascular risk factors.

PubMed Central

Wones, R G; Stadler, B L; Frohman, L A

1990-01-01

Higher cardiovascular mortality has been associated in a single epidemiological study with higher levels of barium in drinking water. The purpose of this study was to determine whether drinking water barium at levels found in some U.S. communities alters the known risk factors for cardiovascular disease. Eleven healthy men completed a 10-week dose-response protocol in which diet was controlled (600 mg cholesterol; 40% fat, 40% carbohydrate, 20% protein; sodium and potassium controlled at the subject's pre-protocol estimated intake). Other aspects of the subjects' lifestyles known to affect cardiac risk factors were controlled, and the barium content (as barium chloride) of the drinking water (1.5 L/day) was varied from 0 (first 2 weeks), to 5 ppm (next 4 weeks), to 10 ppm (last 4 weeks). Multiple blood and urine samples, morning and evening blood pressure measurements, and 48-hr electrocardiographic monitoring were performed at each dose of barium. There were no changes in morning or evening systolic or diastolic blood pressures, plasma cholesterol or lipoprotein or apolipoprotein levels, serum potassium or glucose levels, or urine catecholamine levels. There were no arrhythmias related to barium exposure detected on continuous electrocardiographic monitoring. A trend was seen toward increased total serum calcium levels with exposure to barium, which was of borderline statistical significance and of doubtful clinical significance. In summary, drinking water barium at levels of 5 and 10 ppm did not appear to affect any of the known modifiable cardiovascular risk factors. PMID:2384067

Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

PubMed

Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

2015-10-01

Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

An electrocardiographic, molecular and biochemical approach to explore the cardioprotective effect of vasopressin and milrinone against phosphide toxicity in rats.

PubMed

Jafari, Abbas; Baghaei, Amir; Solgi, Reza; Baeeri, Maryam; Chamanara, Mohsen; Hassani, Shokoufeh; Gholami, Mahdi; Ostad, Seyed Nasser; Sharifzadeh, Moahmmad; Abdollahi, Mohammad

2015-06-01

The present study was conducted to identify the protective effect of vasopressin (AVP) and milrinone on cardiovascular function, mitochondrial complex activities, cellular ATP reserve, oxidative stress, and apoptosis in rats poisoned by aluminum phosphide (AlP). Rats were divided into five groups (n = 12) including control, AlP (12.5 mg/kg), AlP + AVP (2.0 Units/kg), AlP + milrinone (0.25 mg/kg) and AlP + AVP + milrinone. After treatment, the animals were connected to an electronic cardiovascular monitoring device to monitor electrocardiographic (ECG) parameter. Finally, oxidative stress biomarkers, mitochondrial complex activities, ADP/ATP ratio and apoptosis were evaluated on the heart tissues. Results indicated that AlP administration induced ECG abnormalities along with a decline in blood pressure and heart rate. AVP and milrinone significantly ameliorated these changes in all treated groups. Considerable protective effects on oxidative stress biomarkers, complex IV activity, ADP/ATP ratio and caspase-3 and -9 activities in treated groups were also found. These findings were supported by flow cytometry assay of cardiomyocytes. In conclusion, administration of AVP and milrinone, not only improve cardiovascular functions in AlP poisoned rats in the short time, but after a long time can also restore mitochondrial function and ATP level and reduce the oxidative damage, which prevent cardiomyocytes from entering the apoptotic phase. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrocardiographic predictors of adverse cardiovascular events in suspected poisoning.

PubMed

Manini, Alex F; Nelson, Lewis S; Skolnick, Adam H; Slater, William; Hoffman, Robert S

2010-06-01

Poisoning is the second leading cause of injury-related fatality in the USA and the leading cause of cardiac arrest in victims under 40 years of age. The study objective was to define the electrocardiographic (ECG) predictors of adverse cardiovascular events (ACVE) complicating suspected acute poisoning (SAP). This was a case-control study in adults at three tertiary-care hospitals and one regional Poison Control Center. We compared 34 cases of SAP complicated by ACVE to 101 consecutive control patients with uncomplicated SAP. The initial ECG was analyzed for rhythm, intervals, QT dispersion, ischemia, and infarction. ECGs were interpreted by a cardiologist, blinded to study hypothesis and case data. Subjects were 48% male, with mean age 42 +/- 19 years. In addition to clinical suspicion of poisoning in 100% of patients, routine toxicology screens were positive in 77%, most commonly for benzodiazepines, opioids, and/or acetaminophen. Neither the ventricular rate, the QRS duration, nor the presence of infarction predicted the risk of ACVE. However, the rhythm, QTc, QT dispersion, and presence of ischemia correlated with the risk of ACVE. Independent predictors of ACVE based on multivariable logistic regression were prolonged QTc, any non-sinus rhythm, ventricular ectopy, and ischemia. Recursive partitioning analysis identified very low risk criteria (94.1% sensitivity, 96.2% NPV) and high risk criteria (95% specificity). Among patients with SAP, the presence of QTc prolongation, QT dispersion, ventricular ectopy, any non-sinus rhythm, and evidence of ischemia on the initial ECG are strongly associated with ACVE.

Evaluation of electrocardiographic parameters in patients with diabetes insipidus.

PubMed

Deniz, Ferhat; Kepez, Alper; Ay, Seyit Ahmet; Ergogan, Okan; Baskoy, Kamil; Guncıkan, Mustafa Nuri; Dogan, Zekeriya; Yonem, Arif

2015-11-01

There is limited data regarding the effect of altered serum osmolality on cardiac electrical activity. The aim of the present study is to evaluate the electrocardiographic (ECG) effects of diabetes insipidus (DI) and any related hyperosmolality in a population of young patients with DI and without any known cardiovascular disease or risk factors. Twelve-lead ECG's of 44 consecutive untreated young male patients (age: 21.8 ± 2.9 years) who had been referred to endocrinology clinic and diagnosed as DI based on water deprivation test were retrospectively evaluated. A total of 30 age-matched (21.9 ± 2.4 years) healthy males were selected as control group and ECG's of these controls were obtained for comparison with ECG's of DI patients. All ECG parameters were measured and compared. Duration of QRS complex was significantly shorter in patients with DI compared with controls (85.2 ± 12.0 vs. 94.0 ± 10.6 ms, p: 0.001). P wave dispersion (PWD) of patients with DI was significantly higher compared with controls (31.9 ± 9.9 vs. 26.5 ± 10.6 ms, p: 0.03) and it was significantly correlated with serum osmolality and serum sodium level (r = - 0.36, p: 0.02 and r: - 0.35, p: 0.02, respectively). DI patients without any cardiovascular disease or risk factors displayed significantly shorter QRS duration and increased p wave dispersion compared with controls.

Electrocardiograph-gated single photon emission computed tomography radionuclide angiography presents good interstudy reproducibility for the quantification of global systolic right ventricular function.

PubMed

Daou, Doumit; Coaguila, Carlos; Vilain, Didier

2007-05-01

Electrocardiograph-gated single photon emission computed tomography (SPECT) radionuclide angiography provides accurate measurement of right ventricular ejection fraction and end-diastolic and end-systolic volumes. In this study, we report the interstudy precision and reliability of SPECT radionuclide angiography for the measurement of global systolic right ventricular function using two, three-dimensional volume processing methods (SPECT-QBS, SPECT-35%). These were compared with equilibrium planar radionuclide angiography. Ten patients with chronic coronary artery disease having two SPECT and planar radionuclide angiography acquisitions were included. For the right ventricular ejection fraction, end-diastolic volume and end-systolic volume, the interstudy precision and reliability were better with SPECT-35% than with SPECT-QBS. The sample sizes needed to objectify a change in right ventricular volumes or ejection fraction were lower with SPECT-35% than with SPECT-QBS. The interstudy precision and reliability of SPECT-35% and SPECT-QBS for the right ventricle were better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography on the same population. SPECT-35% and SPECT-QBS present good interstudy precision and reliability for right ventricular function, with the results favouring the use of SPECT-35%. The results are better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography. They need to be confirmed in a larger population.

Optimal electrocardiographic limb lead set for rapid emphysema screening

PubMed Central

Bajaj, Rishi; Chhabra, Lovely; Basheer, Zainab; Spodick, David H

2013-01-01

Background Pulmonary emphysema of any etiology has been shown to be strongly and quasidiagnostically associated with a vertical frontal P wave axis. A vertical P wave axis (>60 degrees) during sinus rhythm can be easily determined by a P wave in lead III greater than the P wave in lead I (bipolar lead set) or a dominantly negative P wave in aVL (unipolar lead set). The purpose of this investigation was to determine which set of limb leads may be better for identifying the vertical P vector of emphysema in adults. Methods Unselected consecutive electrocardiograms from 100 patients with a diagnosis of emphysema were analyzed to determine the P wave axis. Patients aged younger than 45 years, those not in sinus rhythm, and those with poor quality tracings were excluded. The electrocardiographic data were divided into three categories depending on the frontal P wave axis, ie, >60 degrees, 60 degrees, or <60 degrees, by each criterion (P amplitude lead III > lead I and a negative P wave in aVL). Results Sixty-six percent of patients had a P wave axis > 60 degrees based on aVL, and 88% of patients had a P wave axis > 60 degrees based on the P wave in lead III being greater than in lead I. Conclusion A P wave in lead III greater than that in lead I is a more sensitive marker than a negative P wave in aVL for diagnosing emphysema and is recommended for rapid routine screening. PMID:23378754

Increase in electrocardiographic R-waves after revascularization in patients with acute myocardial infarction.

PubMed

Isobe, Satoshi; Takada, Yasuo; Ando, Akitada; Ohshima, Satoru; Yamada, Kiyoyasu; Nanasato, Mamoru; Unno, Kazumasa; Ogawa, Takuo; Kondo, Takahisa; Izawa, Hideo; Inden, Yasuya; Hirai, Makoto; Murohara, Toyoaki

2006-11-01

The physiological mechanism of the increase in the electrocardiographic (ECG) R-wave voltage after revascularization in patients with acute myocardial infarction (MI) needs to be elucidated. One hundred and thirty-eight MI patients (83: anterior MI, 45: inferior MI, 10: lateral MI) underwent ECG and echocardiography in both the acute and subacute phases after emergency revascularization, as well as a resting thallium-201/iodine-123 15-p-iodophenyl-3-(R,S)-methyl pentadecanoic acid myocardial scintigraphy in the acute phase. The total sum of the R-wave voltage (SigmaR) was calculated over multiple leads on ECG for each infarcted lesion. Scintigraphic defect on each tracer was expressed as the percentage (%) defect of the total left ventricular (LV) myocardium. The % defect-discordance on both images in the acute phase and the % increase in SigmaR and the absolute increase in LV ejection fraction from the acute to the subacute phase (DeltaEF) were also calculated. The SigmaR in the subacute phase was significantly greater than that in the acute phase (p<0.0001). The % increase in SigmaR significantly correlated with the DeltaEF (r=0.57, p<0.0001). The % increase in SigmaR also correlated with the % defect-discordance (r=0.68, p<0.0001). The increase in the ECG R-wave voltage reflects not only the improvement in myocardial perfusion but also the presence of salvaged myocardium after revascularization in acute MI patients.

Proposed In-Training Electrocardiogram Interpretation Competencies for Undergraduate and Postgraduate Trainees.

PubMed

Antiperovitch, Pavel; Zareba, Wojciech; Steinberg, Jonathan S; Bacharova, Ljuba; Tereshchenko, Larisa G; Farre, Jeronimo; Nikus, Kjell; Ikeda, Takanori; Baranchuk, Adrian

2018-03-01

Despite its importance in everyday clinical practice, the ability of physicians to interpret electrocardiograms (ECGs) is highly variable. ECG patterns are often misdiagnosed, and electrocardiographic emergencies are frequently missed, leading to adverse patient outcomes. Currently, many medical education programs lack an organized curriculum and competency assessment to ensure trainees master this essential skill. ECG patterns that were previously mentioned in literature were organized into groups from A to D based on their clinical importance and distributed among levels of training. Incremental versions of this organization were circulated among members of the International Society of Electrocardiology and the International Society of Holter and Noninvasive Electrocardiology until complete consensus was reached. We present reasonably attainable ECG interpretation competencies for undergraduate and postgraduate trainees. Previous literature suggests that methods of teaching ECG interpretation are less important and can be selected based on the available resources of each education program and student preference. The evidence clearly favors summative trainee evaluation methods, which would facilitate learning and ensure that appropriate competencies are acquired. Resources should be allocated to ensure that every trainee reaches their training milestones and should ensure that no electrocardiographic emergency (class A condition) is ever missed. We hope that these guidelines will inform medical education programs and encourage them to allocate sufficient resources and develop organized curricula. Assessments must be in place to ensure trainees acquire the level-appropriate ECG interpretation skills that are required for safe clinical practice. © 2017 Society of Hospital Medicine.

Electrocardiographic characteristics of atrioventricular block induced by tilt testing.

PubMed

Zyśko, Dorota; Gajek, Jacek; Koźluk, Edward; Mazurek, Walentyna

2009-02-01

The electrocardiographic (ECG) characteristics of atrioventricular (AV) block during reflex syncope may be unique due to the presence of hypervagotonia. The aim of the present study was to define the ECG characteristics of the AV block induced by neurocardiogenic reflex provoked by tilt testing (TT). A series of 31 patients with presumed vasovagal syncope and AV block provoked by TT was studied. The duration of PP and PR interval, AV block grade and type, concomitant arrhythmias, and timing of the AV block occurrence were assessed. The AV block occurred at TT termination in 26 patients, in the recovery in 4 patients, and in both periods in 1 patient. Atrioventricular block was preceded by sinus slowing, and sinus rhythm during AV block was slow and instable. Mobitz I, 2:1 second-degree AV block, and advanced second-degree AV block were recognized in 35.5, 48.4, and 67.8% of patients, respectively. Third-degree AV block was diagnosed in 41.9% of patients. Twenty-one patients had at least two AV block forms. The most prevalent concomitant arrhythmia was junctional escape rhythm (61.3%). (i) The occurrence of the AV block during neurocardiogenic reaction induced by TT is always preceded by sinus rhythm slowing and usually by PR interval prolongation. (ii) The AV block provoked by TT usually occurs at TT termination, but may occur even in the recovery period in a supine position. Sometimes the AV block may be present both at TT termination and during the recovery period.

Athlete's heart patterns in elite rugby players: effects of training specificities.

PubMed

Chevalier, Laurent; Kervio, Gaëlle; Corneloup, Luc; Vincent, Marie-Pierre; Baudot, Christophe; Rebeyrol, Jean-Louis; Merle, Francis; Gencel, Laurent; Carré, François

2013-02-01

Athlete's heart patterns have been widely described. However, to our knowledge, few studies have focused on professional rugby players, who train differently according to their field position. To describe electrocardiographic and echocardiographic patterns observed in elite rugby players according to their field position. One hundred and thirty-five professional rugby players at the end of the competitive season were included. According to a modified Pelliccia's classification, 68.1% of electrocardiograms were normal or had minor abnormalities, 27.2% were mildly abnormal and 3.7% were distinctly abnormal. Heart rate was higher in scrum first-row players (P<0.05). Absolute and indexed left ventricular end-diastolic internal diameters (LVIDd; absolute value 59.3±4.7 mm) exceeded 65 mm and 32 mm/m2 in 13% and 1.5% of players, respectively. Indexed LVIDd values were higher in back players (P<0.001). Left ventricular interventricular septum and posterior wall thicknesses (absolute values 9.4±1.7 mm and 9.2±1.6 mm, respectively) exceeded 13 mm in 3.7% of players. Concentric cardiac hypertrophy was noted in 3.7% of players. Except for one Wolff-Parkinson-White pattern, players with significant ECG or echocardiographic abnormalities showed no cardiovascular event or disease during follow-up. Thus, elite rugby players present similar heart patterns to elite athletes in other sports. Major electrocardiographic and echocardiographic abnormalities are quite rare. Eccentric cardiac remodelling is more frequent in back players. Copyright © 2013. Published by Elsevier Masson SAS.

Evaluation of a New Shirt-Based Electrocardiogram Device for Cardiac Screening in Soccer Players: Comparative Study With Treadmill Ergospirometry

PubMed Central

Fabregat-Andres, Oscar; Munoz-Macho, Adolfo; Adell-Beltran, Guillermo; Ibanez-Catala, Xavier; Macia, Agustin; Facila, Lorenzo

2014-01-01

Background Prevention of cardiac events during competitive sports is fundamental. New technologies with remote monitoring systems integrated into clothing could facilitate the screening of heart disease. Our aim was to evaluate the feasibility of Nuubo system during a field stress test performed by soccer players, comparing results with treadmill ergospirometry as test reference. Methods Nineteen male professional soccer players (19.2 ± 1.6 years) were studied. Wireless electrocardiographic monitoring during a Yo-Yo intermittent recovery test level 1 in soccer field and subsequent analysis of arrhythmias were firstly performed. Subsequently, in a period no longer than 4 weeks, each player underwent cardiopulmonary exercise testing in hospital. Results During Yo-Yo test, electrocardiogram (ECG) signal was interpretable in 16 players (84.2%). In the other three players, ECG artifacts did not allow a proper analysis. Estimation of maximum oxygen consumption was comparable between two exercise tests (VO2 max 53.3 ± 2.4 vs. 53.7 ± 3.0 mL/kg/min for Yo-Yo test and ergometry respectively; intra-class correlation coefficient 0.84 (0.63 - 0.93), P < 0.001). No arrhythmias were detected in any player during both tests. Conclusions The use of Nuubo’s technology allows an accurate single-lead electrocardiographic recording and estimation of reliable performance variables during exercise testing in field, and provides a new perspective to cardiac remote monitoring in collective sports. PMID:28348705

Assessment of electrocardiographic criteria of left atrial enlargement.

PubMed

Batra, Mahesh Kumar; Khan, Atif; Farooq, Fawad; Masood, Tariq; Karim, Musa

2018-05-01

Background Left atrial enlargement is considered to be a robust, strong, and widely acceptable indicator of cardiovascular outcomes. Echocardiography is the gold standard for measurement of left atrial size, but electrocardiography can be simple, cost-effective, and noninvasive in clinical practice. This study was undertaken to assess the diagnostic accuracy of an established electrocardiographic criterion for left atrial enlargement, taking 2-dimensional echocardiography as the gold-standard technique. Methods A cross-sectional study was conducted on 146 consecutively selected patients with the complaints of dyspnea and palpitation and with a murmur detected on clinical examination, from September 10, 2016 to February 10, 2017. Electrocardiography and echocardiography were performed in all patients. Patients with a negative P wave terminal force in lead V 1  > 40 ms·mm on electrocardiography or left atrial dimension > 40 mm on echocardiography were classified as having left atrial enlargement. Sensitivity and specificity were calculated to assess the diagnostic accuracy. Results Taking 2-dimensional echocardiography as the gold-standard technique, electrocardiography correctly diagnosed 68 patients as positive for left atrial enlargement and 12 as negative. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of electrocardiography for left atrial enlargement were 54.4%, 57.1%, 88.3%, 17.4%, and 54.8%, respectively. Conclusion The electrocardiogram appears to be a reasonable indicator of left atrial enlargement. In case of nonavailability of echocardiography, electrocardiography can be used for diagnosis of left atrial enlargement.

Acute effects of Red Bull energy drink on ventricular repolarization in healthy young volunteers: a prospective study.

PubMed

Elitok, Ali; Öz, Fahrettin; Panc, Cafer; Sarıkaya, Remzi; Sezikli, Selim; Pala, Yasin; Bugan, Övgü Sinem; Ateş, Müge; Parıldar, Hilal; Ayaz, Mustafa Buğra; Atıcı, Adem; Oflaz, Hüseyin

2015-11-01

Energy drinks (EDs) are widely consumed products of the beverage industry and are often chosen by teenagers and young adults. Several adverse cardiovascular events and malignant cardiac arrhythmias following consumption of EDs have been reported in the literature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the dispersion of repolarization and that an increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. This study investigated the acute effects of Red Bull ED on ventricular repolarization as assessed by the Tp-e interval and Tp-e/QT ratio. A prospective, open-label study design was used. After an 8-h fast, 50 young, healthy subjects consumed 355 mL of Red Bull ED. The Tp-e interval, Tp-e/QTc ratio, and several other electrocardiographic parameters were measured at baseline and 2 h after ingestion of Red Bull ED. No significant changes in the Tp-e interval or Tp-e/QTc ratio were observed with Red Bull ED consumption. Red Bull ED consumption led to increases in both systolic and diastolic blood pressures, which were associated with an increased heart rate. Although ingestion of Red Bull ED increases the heart rate and diastolic and systolic blood pressures, it does not cause alterations in ventricular repolarization as assessed by the Tp-e interval and Tp-e/QTc ratio.

Electrocardiographic left ventricular hypertrophy predicts recurrence of atrial arrhythmias after catheter ablation of paroxysmal atrial fibrillation.

PubMed

Li, Song-Nan; Wang, Lu; Dong, Jian-Zeng; Yu, Rong-Hui; Long, De-Yong; Tang, Ri-Bo; Sang, Cai-Hua; Jiang, Chen-Xi; Liu, Nian; Bai, Rong; Du, Xin; Ma, Chang-Sheng

2018-06-01

Left ventricular hypertrophy (LVH) is an independent predictor of new-onset atrial fibrillation. Whether LVH can predict the recurrence of arrhythmia after radiofrequency catheter ablation (RFCA) in patients with paroxysmal atrial fibrillation (PAF) remains unclear. PAF patients with baseline-electrocardiographic LVH has a higher recurrence rate after RFCA procedure compared with those without LVH. A total of 436 patients with PAF undergoing first RFCA were consecutively enrolled and clustered into 2 groups based on electrocardiogram (ECG) findings: non-ECG LVH (218 patients) and ECG LVH (218 patients). LVH was characterized by the Romhilt-Estes point score system; the score ≥5points were defined as LVH. At 42 months' (interquartile range, 18.0-60.0 months) follow-up after RFCA, 151 (69.3%) patients in the non-ECG LVH group and 108 (49.5%) patients in the ECG LVH group maintained sinus rhythm without using antiarrhythmic drugs (P < 0.001). Patients with ECG LVH tended to experience a much higher prevalence of stroke and recurrence of atrial arrhythmia episodes compared with those without ECG LVH (log-rank P < 0.001). Multivariate analysis found the presence of ECG LVH and left atrial diameter to be independent risk factors for recurrence after adjusting for confounding factors. The presence of ECG LVH was a strong and independent predictor of recurrence in patients with PAF following RFCA. © 2018 Wiley Periodicals, Inc.

Separation of electrocardiographic from electromyographic signals using dynamic filtration.

PubMed

Christov, Ivaylo; Raikova, Rositsa; Angelova, Silvija

2018-07-01

Trunk muscle electromyographic (EMG) signals are often contaminated by the electrical activity of the heart. During low or moderate muscle force, these electrocardiographic (ECG) signals disturb the estimation of muscle activity. Butterworth high-pass filters with cut-off frequency of up to 60 Hz are often used to suppress the ECG signal. Such filters disturb the EMG signal in both frequency and time domain. A new method based on the dynamic application of Savitzky-Golay filter is proposed. EMG signals of three left trunk muscles and pure ECG signal were recorded during different motor tasks. The efficiency of the method was tested and verified both with the experimental EMG signals and with modeled signals obtained by summing the pure ECG signal with EMG signals at different levels of signal-to-noise ratio. The results were compared with those obtained by application of high-pass, 4th order Butterworth filter with cut-off frequency of 30 Hz. The suggested method is separating the EMG signal from the ECG signal without EMG signal distortion across its entire frequency range regardless of amplitudes. Butterworth filter suppresses the signals in the 0-30 Hz range thus preventing the low-frequency analysis of the EMG signal. An additional disadvantage is that it passes high-frequency ECG signal components which is apparent at equal and higher amplitudes of the ECG signal as compared to the EMG signal. The new method was also successfully verified with abnormal ECG signals. Copyright © 2018. Published by Elsevier Ltd.

Association of Age, Sex, Body Size and Ethnicity with Electrocardiographic Values in Community-based Older Asian Adults.

PubMed

Tan, Eugene S J; Yap, Jonathan; Xu, Chang Fen; Feng, Liang; Nyunt, Shwe Zin; Santhanakrishnan, Rajalakshmi; Chan, Michelle M Y; Seow, Swee Chong; Ching, Chi Keong; Yeo, Khung Keong; Richards, A Mark; Ng, Tze Pin; Lim, Toon Wei; Lam, Carolyn S P

2016-07-01

Existing electrocardiographic (ECG) reference values were derived in middle-aged Caucasian adults. We aimed to assess the association of age, sex, body size and ethnicity on ECG parameters in a multi-ethnic Asian population. Resting 12-lead ECG and anthropometric measurements were performed in a community-based cohort of 3777 older Asians (age 64.7±9.1 years, 1467 men, 88.8% Chinese, 7.7% Malay, 3.5% Indian, body mass index [BMI] 24.0±3.9kg/m(2)). Men had longer PR interval, wider QRS, shorter QTc interval and taller SV3. In both sexes, older age was associated with longer PR interval, wider QRS, larger R aVL and more leftward QRS axis, while higher BMI was associated with longer PR interval, wider QRS, larger RaVL and more negative QRS axis. There were significant inter-ethnic differences in QRS duration among men, as well as in PR and QTc intervals among women (all adjusted p<0.05). Findings were similar in a healthy subset of 1158 adults (age 61.2±9.1 years, 365 men) without cardiovascular risk factors. These first community-based ECG data in multi-ethnic older Asians highlight the independent effects of age, sex, body size and ethnicity on ECG parameters. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Individual Biometric Identification Using Multi-Cycle Electrocardiographic Waveform Patterns.

PubMed

Lee, Wonki; Kim, Seulgee; Kim, Daeeun

2018-03-28

The electrocardiogram (ECG) waveform conveys information regarding the electrical property of the heart. The patterns vary depending on the individual heart characteristics. ECG features can be potentially used for biometric recognition. This study presents a new method using the entire ECG waveform pattern for matching and demonstrates that the approach can potentially be employed for individual biometric identification. Multi-cycle ECG signals were assessed using an ECG measuring circuit, and three electrodes can be patched on the wrists or fingers for considering various measurements. For biometric identification, our-fold cross validation was used in the experiments for assessing how the results of a statistical analysis will generalize to an independent data set. Four different pattern matching algorithms, i.e., cosine similarity, cross correlation, city block distance, and Euclidean distances, were tested to compare the individual identification performances with a single channel of ECG signal (3-wire ECG). To evaluate the pattern matching for biometric identification, the ECG recordings for each subject were partitioned into training and test set. The suggested method obtained a maximum performance of 89.9% accuracy with two heartbeats of ECG signals measured on the wrist and 93.3% accuracy with three heartbeats for 55 subjects. The performance rate with ECG signals measured on the fingers improved up to 99.3% with two heartbeats and 100% with three heartbeats of signals for 20 subjects.

Noninvasive Diagnosis of Coronary Artery Disease Using 12-Lead High-Frequency Electrocardiograms

NASA Technical Reports Server (NTRS)

Schlegel, Todd T.; Arenare, Brian

2006-01-01

A noninvasive, sensitive method of diagnosing certain pathological conditions of the human heart involves computational processing of digitized electrocardiographic (ECG) signals acquired from a patient at all 12 conventional ECG electrode positions. In the processing, attention is focused on low-amplitude, high-frequency components of those portions of the ECG signals known in the art as QRS complexes. The unique contribution of this method lies in the utilization of signal features and combinations of signal features from various combinations of electrode positions, not reported previously, that have been found to be helpful in diagnosing coronary artery disease and such related pathological conditions as myocardial ischemia, myocardial infarction, and congestive heart failure. The electronic hardware and software used to acquire the QRS complexes and perform some preliminary analyses of their high-frequency components were summarized in Real-Time, High-Frequency QRS Electrocardiograph (MSC- 23154), NASA Tech Briefs, Vol. 27, No. 7 (July 2003), pp. 26-28. To recapitulate, signals from standard electrocardiograph electrodes are preamplified, then digitized at a sampling rate of 1,000 Hz, then analyzed by the software that detects R waves and QRS complexes and analyzes them from several perspectives. The software includes provisions for averaging signals over multiple beats and for special-purpose nonrecursive digital filters with specific low- and high-frequency cutoffs. These filters, applied to the averaged signal, effect a band-pass operation in the frequency range from 150 to 250 Hz. The output of the bandpass filter is the desired high-frequency QRS signal. Further processing is then performed in real time to obtain the beat-to-beat root mean square (RMS) voltage amplitude of the filtered signal, certain variations of the RMS voltage, and such standard measures as the heart rate and R-R interval at any given time. A key signal feature analyzed in the present method is the presence versus the absence of reduced-amplitude zones (RAZs). In terms that must be simplified for the sake of brevity, an RAZ comprises several cycles of a high-frequency QRS signal during which the amplitude of the high-frequency oscillation in a portion of the signal is abnormally low (see figure). A given signal sample exhibiting an interval of reduced amplitude may or may not be classified as an RAZ, depending on quantitative criteria regarding peaks and troughs within the reduced-amplitude portion of the high-frequency QRS signal. This analysis is performed in all 12 leads in real time.

Use of electromyographic and electrocardiographic signals to detect sleep bruxism episodes in a natural environment.

PubMed

Castroflorio, Tommaso; Mesin, Luca; Tartaglia, Gianluca Martino; Sforza, Chiarella; Farina, Dario

2013-11-01

Diagnosis of bruxism is difficult since not all contractions of masticatory muscles during sleeping are bruxism episodes. In this paper, we propose the use of both EMG and ECG signals for the detection of sleep bruxism. Data have been acquired from 21 healthy volunteers and 21 sleep bruxers. The masseter surface EMGs were detected with bipolar concentric electrodes and the ECG with monopolar electrodes located on the clavicular regions. Recordings were made at the subjects' homes during sleeping. Bruxism episodes were automatically detected as characterized by masseter EMG amplitude greater than 10% of the maximum and heart rate increasing by more than 25% with respect to baseline within 1 s before the increase in EMG amplitude above the 10% threshold. Furthermore, the subjects were classified as bruxers and nonbruxers by a neural network. The number of bruxism episodes per night was 24.6 ± 8.4 for bruxers and 4.3 ± 4.5 for controls ( P < 0.0001). The classification error between bruxers and nonbruxers was 1% which was substantially lower than when using EMG only for the classification. These results show that the proposed system, based on the joint analysis of EMG and ECG, can provide support for the clinical diagnosis of bruxism.

Myopericarditis during a primary Epstein-Barr virus infection in an otherwise healthy young adult. An unusual and insidious complication. Case report and a 60-year literature review.

PubMed

Sabbatani, Sergio; Manfredi, Roberto; Ortolani, Paolo; Trapani, Fabio Filippo; Viale, Pierluigi

2012-06-01

An otherwise healthy young man had infectious mononucleosis detected after an atypical clinical onset, including myocarditis and pericarditis. Our patient slowly but completely recovered from his cardiac complications after the course of his primary Epstein-Barr infection, as shown by periodical electrocardiographic and ultrasonographic studies, and a simple treatment with aspirin alone. Our case report is briefly reported, and discussed with regard to the existing literature, which has recorded such complications since the mid 1940s.

Utility of the Electrocardiogram in Drug Overdose and Poisoning: Theoretical Considerations and Clinical Implications

PubMed Central

Yates, Christopher; Manini, Alex F

2012-01-01

The ECG is a rapidly available clinical tool that can help clinicians manage poisoned patients. Specific myocardial effects of cardiotoxic drugs have well-described electrocardiographic manifestations. In the practice of clinical toxicology, classic ECG changes may hint at blockade of ion channels, alterations of adrenergic tone, or dysfunctional metabolic activity of the myocardium. This review will offer a structured approach to ECG interpretation in poisoned patients with a focus on clinical implications and ECG-based management recommendations in the initial evaluation of patients with acute cardiotoxicity. PMID:22708912

Electrocardiographical case. A tale of tall T's. Hyperkalaemia.

PubMed

Chew, H C; Lim, S H

2005-08-01

A 63-year-old woman presented at the emergency department (ED) with a history of increasing lethargy and drowsiness. The electrocardiogram (ECG) showed tall peaked T waves with broadening of the QRS interval, suggestive of hyperkalaemia. This patient had an elevated serum potassium level due to diabetic ketoacidosis. She was treated with intravenous calcium chloride and insulin with 50% dextrose. The ECG changes associated with hyperkalaemia are discussed, with illustrations from a second 48-year-old male patient with renal failure who presented with malaise, lethargy and generalised weakness.

Creation of a genetic calcium channel blocker by targeted gem gene transfer in the heart.

PubMed

Murata, Mitsushige; Cingolani, Eugenio; McDonald, Amy D; Donahue, J Kevin; Marbán, Eduardo

2004-08-20

Calcium channel blockers are among the most commonly used therapeutic drugs. Nevertheless, the utility of calcium channel blockers for heart disease is limited because of the potent vasodilatory effect that causes hypotension, and other side effects attributable to blockade of noncardiac channels. Therefore, focal calcium channel blockade by gene transfer is highly desirable. With a view to creating a focally applicable genetic calcium channel blocker, we overexpressed the ras-related small G-protein Gem in the heart by somatic gene transfer. Adenovirus-mediated delivery of Gem markedly decreased L-type calcium current density in ventricular myocytes, resulting in the abbreviation of action potential duration. Furthermore, transduction of Gem resulted in a significant shortening of the electrocardiographic QTc interval and reduction of left ventricular systolic function. Focal delivery of Gem to the atrioventricular (AV) node significantly slowed AV nodal conduction (prolongation of PR and AH intervals), which was effective in the reduction of heart rate during atrial fibrillation. Thus, these results indicate that gene transfer of Gem functions as a genetic calcium channel blocker, the local application of which can effectively modulate cardiac electrical and contractile function.

Is speckle tracking actually helpful for cardiac resynchronization therapy?

PubMed

Tanaka, Hidekazu; Hirata, Ken-Ichi

2016-06-01

What is the specific role of echocardiography in cardiac resynchronization therapy (CRT)? CRT has proven to be highly effective for improving symptoms and survival of patients with advanced heart failure (HF) and wide QRS. However, a significant minority of patients do not respond favorably to CRT on the basis of standard clinical selection criteria, including the electrocardiographic QRS width. Subsequently, echocardiographic assessment of left ventricular (LV) dyssynchrony has been considered useful for CRT for selected responders, but findings by multicenter studies suggest that its predictive value was not sufficiently robust to replace routine selection criteria for CRT. A more recent approach, however, using speckle-tracking echocardiography yields more accurate quantification of regional wall contraction. Speckle-tracking approaches have therefore generated a great deal of interest about their clinical applications for CRT. Although reports on speckle tracking have not been included in any recommendations as to whether patients should undergo CRT based on the current guidelines, speckle tracking can play an important supplementary part in CRT on the basis of a case-by-case clinical decision for challenging cases. Here, we review the strengths of speckle-tracking methods, and their current potential for clinical use in CRT.

Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management.

PubMed

Margulescu, Andrei D; Mont, Lluis

2017-08-01

Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.

Clinical evaluation of automated processing of electrocardiograms by the Veterans Administration program (AVA 3.4).

PubMed

Brohet, C R; Richman, H G

1979-06-01

Automated processing of electrocardiograms by the Veterans Administration program was evaluated for both agreement with physician interpretation and interpretative accuracy as assessed with nonelectrocardiographic criteria. One thousand unselected electrocardiograms were analyzed by two reviewer groups, one familiar and the other unfamiliar with the computer program. A significant number of measurement errors involving repolarization changes and left axis deviation occurred; however, interpretative disagreements related to statistical decision were largely language-related. Use of a printout with a more traditional format resulted in agreement with physician interpretation by both reviewer groups in more than 80 percent of cases. Overall sensitivity based on agreement with nonelectrocardiographic criteria was significantly greater with use of the computer program than with use of the conventional criteria utilized by the reviewers. This difference was particularly evident in the subgroup analysis of myocardial infarction and left ventricular hypertrophy. The degree of overdiagnosis of left ventricular hypertrophy and posteroinferior infarction was initially unacceptable, but this difficulty was corrected by adjustment of probabilities. Clinical acceptability of the Veterans Administration program appears to require greater physician education than that needed for other computer programs of electrocardiographic analysis; the flexibility of interpretation by statistical decision offers the potential for better diagnostic accuracy.

Real-time fusion of endoscopic views with dynamic 3-D cardiac images: a phantom study.

PubMed

Szpala, Stanislaw; Wierzbicki, Marcin; Guiraudon, Gerard; Peters, Terry M

2005-09-01

Minimally invasive robotically assisted cardiac surgical systems currently do not routinely employ 3-D image guidance. However, preoperative magnetic resonance and computed tomography (CT) images have the potential to be used in this role, if appropriately registered with the patient anatomy and animated synchronously with the motion of the actual heart. This paper discusses the fusion of optical images of a beating heart phantom obtained from an optically tracked endoscope, with volumetric images of the phantom created from a dynamic CT dataset. High quality preoperative dynamic CT images are created by first extracting the motion parameters of the heart from the series of temporal frames, and then applying this information to animate a high-quality heart image acquired at end systole. Temporal synchronization of the endoscopic and CT model is achieved by selecting the appropriate CT image from the dynamic set, based on an electrocardiographic trigger signal. The spatial error between the optical and virtual images is 1.4 +/- 1.1 mm, while the time discrepancy is typically 50-100 ms. Index Terms-Image guidance, image warping, minimally invasive cardiac surgery, virtual endoscopy, virtual reality.

Smart healthcare textile sensor system for unhindered-pervasive health monitoring

NASA Astrophysics Data System (ADS)

Rai, Pratyush; Kumar, Prashanth S.; Oh, Sechang; Kwon, Hyeokjun; Mathur, Gyanesh N.; Varadan, Vijay K.; Agarwal, M. P.

2012-04-01

Simultaneous monitoring of physiological parameters- multi-lead Electrocardiograph (ECG), Heart rate variability, and blood pressure- is imperative to all forms of medical treatments. Using an array of signal recording devices imply that the patient will have to be confined to a bed. Textiles offer durable platform for embedded sensor and communication systems. The smart healthcare textile, presented here, is a mobile system for remote/wireless data recording and conditioning. The wireless textile system has been designed to monitor a patient in a non-obstructive way. It has a potential for facilitating point of care medicine and streamlining ambulatory medicine. The sensor systems were designed and fabricated with textile based components for easy integration on textile platform. An innovative plethysmographic blood pressure monitoring system was designed and tested as an alternative to inflatable blood pressure sphygmomanometer. Flexible dry electrodes technology was implemented for ECG. The sensor systems were tested and conditioned to daily activities of patients, which is not permissible with halter type systems. The signal quality was assessed for it applicability to medical diagnosis. The results were used to corroborate smart textile sensor system's ability to function as a point of care system that can provide quality healthcare.

Duplication of 20p12.3 associated with familial Wolff-Parkinson-White syndrome.

PubMed

Mills, Kimberly I; Anderson, Jacqueline; Levy, Philip T; Cole, F Sessions; Silva, Jennifer N A; Kulkarni, Shashikant; Shinawi, Marwan

2013-01-01

Wolff-Parkinson-White (WPW) syndrome is caused by preexcitation of the ventricular myocardium via an accessory pathway which increases the risk for paroxysmal supraventricular tachycardia. The condition is often sporadic and of unknown etiology in the majority of cases. Autosomal dominant inheritance and association with congenital heart defects or ventricular hypertrophy were described. Microdeletions of 20p12.3 have been associated with WPW syndrome with either cognitive dysfunction or Alagille syndrome. Here, we describe the association of 20p12.3 duplication with WPW syndrome in a patient who presented with non-immune hydrops. Her paternal uncle carries the duplication and has attention-deficit hyperactivity disorder and electrocardiographic findings consistent with WPW. The 769 kb duplication was detected by the Affymetrix Whole Genome-Human SNP Array 6.0 and encompasses two genes and the first two exons of a third gene. We discuss the potential role of the genes in the duplicated region in the pathogenesis of WPW and possible neurobehavioral abnormalities. Our data provide additional support for a significant role of 20p12.3 chromosomal rearrangements in the etiology of WPW syndrome. Copyright © 2012 Wiley Periodicals, Inc.

Electrocardiographic abnormalities and arrhythmic risk markers in adult patients with beta thalassemia major.

PubMed

Kolios, Marios; Korantzopoulos, Panagiotis; Vlahos, Antonios P; Kapsali, Eleni; Briasoulis, Evangelos; Goudevenos, John A

2016-10-15

There seems to be a significant arrhythmia burden in β-thalassemia major (TM) patients without overt cardiomyopathy. Apart from conventional electrocardiographic (ECG) and arrhythmic risk markers we studied novel markers of ventricular repolarization and autonomic imbalance both at rest and after exercise testing. We studied 47 adult TM patients without systolic heart failure and 47 age and sex-matched healthy control subjects. The median age of the studied population was 36 [32-43] years, 57% men. Baseline demographic and clinical characteristics were recorded while 12-lead electrocardiograms, 24-hour ECG Holter recordings, and treadmill exercise stress tests were analyzed. TM patients exhibited increased QTc intervals in both 12-lead ECG recordings and in 24-hour Holter recordings. In addition, they had increased indexes of ventricular repolarization heterogeneity such as QT dispersion, and T peak-to-end/QT ratios. Furthermore, TM patients had decreased indexes of heart rate variability while the heart rate recovery after exercise was significantly attenuated compared to controls. Also, they had increased P wave and QRS duration while the QRS fragmentation was very prevalent. Finally, premature atrial extrasystoles and paroxysmal atrial fibrillation episodes were more frequent in TM patients. TM patients with preserved left ventricular systolic function have several ECG abnormalities including alterations in ventricular depolarization and repolarization. Also, cardiac autonomic dysfunction is evident in 24-hour ECG monitoring as well as in the recovery phase after exercise testing. The prognostic value of specific arrhythmic risk indexes in this setting remains to be elucidated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of imposed acid-base derangement on the cardiovascular effects and pharmacokinetics of bupivacaine and thiopental.

PubMed

Mather, Laurence E; Ladd, Leigh A; Copeland, Susan E; Chang, Dennis H-T

2004-06-01

By changing physicochemical properties such as effective lipophilicity, changes in blood pH could alter the distribution, elimination, and effects of weakly ionizing drugs. The authors examined the outcome of imposed acid-base derangement on cardiovascular effects and myocardial and whole body pharmacokinetics of bupivacaine, a weak base, and thiopental, a weak acid. Intravenous infusions of rac-bupivacaine HCl (37.5 mg) or rac-thiopental sodium (250 mg, subanesthetic dose) were administered over 3 min to previously instrumented conscious ewes with normal blood pH, acidemia imposed by lactic acid infusion, or alkalemia imposed by bicarbonate infusion. Hemodynamic and electrocardiographic effects were recorded; arterial and coronary sinus drug blood concentrations were analyzed by chiral high-performance liquid chromatography. Bupivacaine decreased myocardial contractility, coronary perfusion, heart rate, and cardiac output; however, cardiac output and stroke volume were not as affected by bupivacaine with acidemia. Thiopental decreased myocardial contractility and stroke volume and increased heart rate; acidemia enhanced the tachycardia and produced a greater decrease in stroke volume than with alkalemia. Taken as a whole, the cardiovascular changes were not systematically modified by acid-base derangement. Overall, the tissue distribution of bupivacaine was favored by alkalemia, but thiopental pharmacokinetics were essentially unaffected by acid-base derangement. Acid-base derangement did not influence the kinetics of either drug enantioselectively. At the doses used, the hemodynamic and electrocardiographic effects of bupivacaine and thiopental were not systematically modified by acid-base derangement, nor were there changes in regional or whole body pharmacokinetics of either drug that were clearly related to acid-base status.

Peroperative electrocardiographic control of catheter tip position during implantation of femoral venous ports.

PubMed

Gibault, Pierre; Desruennes, Eric; Bourgain, Jean-Louis

2015-01-01

Electrocardiographic (ECG) guidance has been shown to be as effective than fluoroscopy to position the tip of central venous devices close to the superior vena cava (SVC)-right atrium (RA) junction. When SVC access is contraindicated, a femoral access may be used. The aim of this prospective study is to evaluate the effectiveness of ECG guidance to position the tip of femoral ports at inferior vena cava (IVC)-RA junction. Inclusion criterion was the need for femoral port implantation. After insertion of the dilator in the femoral vein, the catheter with the guide wire inside was introduced and the ECG signal collected at the tip of the guide (Celsite™ ECG, B. Braun, Germany) or via saline injected in the catheter (Nautilus™, Perouse, France). Fluoroscopy was performed at each change of the P-wave from IVC to RA. A final X-ray was performed after withdrawing the catheter 2 cm below the first P-wave change. A total of 18 patients were included between December 2011 and June 2013. The P-wave was most often negative in IVC, biphasic when the catheter entered RA and giant and positive at the top of RA. When the catheter was withdraw 2 cm below the first biphasic P-wave the tip was just below the IVC-RA junction in 17 patients. In one patient P-wave changes were not significant and the final position was adjusted under fluoroscopy. ECG guidance is effective to assess catheter tip position during femoral port placement and avoids the need for radiological methods.

Misidentification of maternal heart rate as fetal on cardiotocography during the second stage of labor: the role of the fetal electrocardiograph.

PubMed

Nurani, Raisha; Chandraharan, Edwin; Lowe, Virginia; Ugwumadu, Austin; Arulkumaran, Sabaratnam

2012-12-01

To identify the incidence of fetal heart rate (FHR) accelerations in the second stage of labor and the role of fetal electrocardiograph (ECG) in avoiding misidentification of maternal heart rate (MHR) as FHR. Retrospective observational study. University hospital labor ward, London, UK. Cardiotocograph (CTG) tracings of 100 fetuses monitored using external transducers and internal scalp electrodes. CTG traces that fulfilled inclusion criteria were selected from an electronic FHR monitoring database. Rate of accelerations during external and internal monitoring as well as decelerations for a period of 60 minutes prior to delivery were determined. The role of fetal ECG in differentiating between MHR and FHR trace was explored. Decelerations occurred in 89% of CTG traces during the second stage of labor. Accelerations indicating possible recording of FHR or MHR were found in 28.1 and 10.9% of cases recorded by an external ultrasound transducer as well as internal scalp electrode, respectively. Accelerations coinciding with uterine contractions occurred only in 11.7 and 4% of external and internal recording of FHR, respectively. Absence of 'p-wave' of the ECG waveform was associated with MHR trace. Decelerations were the commonest CTG feature during the second stage of labor. The incidence of accelerations coinciding with uterine contractions was less than half in fetuses monitored using a fetal scalp electrode. Analysing the ECG waveform for the absence of 'p-wave' helps in differentiating MHR from FHR. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

Functional, morphological and electrocardiographical abnormalities in patients with apical hypertrophic cardiomyopathy and apical aneurysm: correlation with cardiac MR

PubMed Central

Suwa, Kenichiro; Satoh, Hiroshi; Sano, Makoto; Nobuhara, Mamoru; Saitoh, Takeji; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Tawarahara, Kei; Ohtani, Hayato; Wakabayashi, Yasushi; Takase, Hiroyuki; Terada, Hajime; Takehara, Yasuo; Sakahara, Harumi; Hayashi, Hideharu

2014-01-01

Objective The prognosis of apical hypertrophic cardiomyopathy (APH) has been benign, but apical myocardial injury has prognostic importance. We studied functional, morphological and electrocardiographical abnormalities in patients with APH and with apical aneurysm and sought to find parameters that relate to apical myocardial injury. Methods Study design: a multicentre trans-sectional study. Patients: 45 patients with APH and 5 with apical aneurysm diagnosed with transthoracic echocardiography (TTE) in the database of Hamamatsu Circulation Forum. Measure: the apical contraction with cine-cardiac MR (CMR), the myocardial fibrotic scar with late gadolinium enhancement (LGE)-CMR, and QRS fragmentation (fQRS) defined when two ECG-leads exhibited RSR’s patterns. Results Cine-CMR revealed 27 patients with normal, 12 with hypokinetic and 11 with dyskinetic apical contraction. TTE misdiagnosed 11 (48%) patients with hypokinetic and dyskinetic contraction as those with normal contraction. Apical LGE was apparent in 10 (83%) and 11 (100%) patients with hypokinetic and dyskinetic contraction, whereas only in 11 patients (41%) with normal contraction (p<0.01). Patients with dyskinetic apical contraction had the lowest left ventricular ejection fraction, the highest prevalence of ventricular tachycardia, and the smallest ST depression and depth of negative T waves. The presence of fQRS was associated with impaired apical contraction and apical LGE (OR=8.32 and 8.61, p<0.05). Conclusions CMR is superior to TTE for analysing abnormalities of the apex in patients with APH and with apical aneurysm. The presence of fQRS can be a promising parameter for the early detection of apical myocardial injury. PMID:25332823

[Interobserver agreement on electrocardiographic diagnosis of left ventricular hypertrophy in hypertensive patients in Andalusia. PREHVIA study].

PubMed

Martín-Rioboó, Enrique; López Granados, Amador; Cea Calvo, Luis; Pérula De Torres, Luis Angel; García Criado, Emilio; Anguita Sánchez, Manuel P; García Matarín, Lisardo; Molina Díaz, Rafael; Ureña Fernández, Tomas

2009-05-01

To assess the agreement between Primary Care (PC) doctors and a cardiology specialist in diagnosing left ventricular hypertrophy in the electrocardiograph (LVH-ECG) in hypertensive patients. Cross-sectional, multicentre study. Andalusian Primary Care Centres. A total of 120 PC doctors who using a random sample selected patients of 35 years or more with AHT of at least 6 months of progression. PRIMARY VARIABLES: Demographic data, risk factors and cardiovascular diseases were recorded. The LVH-ECG was evaluated by applying Cornell voltage criteria, Cornell and Sokolow-Lyon product. The PC researchers read the ECG first and the cardiologist made a second reading blind. A total of 570 patients (mean +/- SD of age, 65 +/- 11 years; 54.5% females); the LVH-ECG prevalence was 13.7% (95% CI, 10.8-16.6; 12.6% by Cornell and 1.6% by Sokolow-Lyon). The agreement in the diagnosis between the PC doctors and the cardiologist was 0.378 (95% CI, 0.272-0.486; disagreements in 15.5% of cases). The PC doctors slightly underestimated the LVH-ECG prevalence by Cornell and slightly overestimated it by the Sokolow-Lyon criteria. The agreement was also low for all of them (kappa = 0.367; 95% CI, 0.252-0.482, for Cornell, and kappa = 0.274; 95% CI: 0.093-0.454 for Sokolow-Lyon). The agreement between the diagnosis by the PC doctors and the cardiologist was low. The implications of this study suggest the need to improve the reading of ECG among PC doctors. The use of computerised systems could be a good option.

Determination of Minimum Data Set (MSD) in Echocardiography Reporting System to Exchange with Iran's Electronic Health Record (EHR) System.

PubMed

Mahmoudvand, Zahra; Kamkar, Mehran; Shahmoradi, Leila; Nejad, Ahmadreza Farzaneh

2016-04-01

Determination of minimum data set (MDS) in echocardiography reports is necessary for documentation and putting information in a standard way, and leads to the enhancement of electrocardiographic studies through having access to precise and perfect reports and also to the development of a standard database for electrocardiographic reports. to determine the minimum data set of echocardiography reporting system to exchange with Iran's electronic health record (EHR) system. First, a list of minimum data set was prepared after reviewing texts and studying cardiac patients' records. Then, to determine the content validity of the prepared MDS, the expert views of 10 cardiologists and 10 health information management (HIM) specialists were obtained; to estimate the reliability of the set, test-retest method was employed. Finally, the data were analyzed using SPSS software. The highest degree of consensus was found for the following MDSs: patient's name and family name (5), accepting doctor's name and family name, familial death records due to cardiac disorders, the image identification code, mitral valve, aortic valve, tricuspid valve, pulmonary valve, left ventricle, hole, atrium valve, Doppler examination of ventricular and atrial movement models and diagnoses with an average of. To prepare a model of echocardiography reporting system to exchange with EHR system, creation a standard data set is the vital point. Therefore, based on the research findings, the minimum reporting system data to exchange with Iran's electronic health record system include information on entity, management, medical record, carried-out acts, and the main content of the echocardiography report, which the planners of reporting system should consider.

Minor Electrocardiographic ST-T Change and Risk of Stroke in the General Japanese Population.

PubMed

Ishikawa, Joji; Hirose, Hideo; Schwartz, Joseph E; Ishikawa, Shizukiyo

2018-06-25

Minor ST-T changes are frequently observed on the electrocardiogram (ECG), but the risk of stroke associated with such changes is unclear.Methods and Results:In 10,642 subjects from the Japanese general population, we evaluated minor and major ST-T changes (major ST depression ≥0.1 mV) on ECGs obtained at annual health examinations. At baseline, minor ST-T changes were found in 10.7% of the subjects and 0.5% had major ST-T changes. Minor ST-T changes were associated with older age, female gender, higher systolic blood pressure, presence of hyperlipidemia, and use of antihypertensive medication. There were 375 stroke events during the follow-up period (128.7±28.1 months). In all subjects, minor ST-T changes (HR, 2.10; 95% CI: 1.57-2.81) and major ST-T changes (HR, 8.64; 95% CI: 4.44-16.82) were associated with an increased risk of stroke, but the stroke risk associated with minor ST-T changes had borderline significance after adjustment for conventional risk factors (P=0.055). In subgroup analysis, the risk of stroke was significantly associated with minor ST-T changes in subjects who had hyperlipidemia (HR, 1.75; 95% CI: 1.15-2.67) compared to those without hyperlipidemia (HR, 1.01; 95% CI: 0.64-1.59; P for interaction=0.016), even after adjustment for ECG-diagnosed left ventricular hypertrophy. Minor ST-T changes were particularly associated with a higher risk of stroke in subjects with hyperlipidemia and this association was independent of electrocardiographic left ventricular hypertrophy.

Preserved hyperaemic response in supraclavicular ultrasonography demonstrates function on demand of the LIMA to LAD string sign graft after CABG.

PubMed

Hartman, J M; Kelder, H C; Ackerstaff, R G A; Swieten, H A; Vermeulen, F E E; Bogers, A J J C

2007-02-01

To correlate supraclavicular ultrasonography with angiographically patent and string sign left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafts. Sixteen patients with a single LIMA anastomosis to the LAD were prospectively entered in a follow-up study. The supraclavicular ultrasonography of the LIMA origin was studied preoperatively and at 5.3+/-3.6 months and 1.7+/-0.4 year postoperatively. At the late postoperative ultrasonography electrocardiographically controlled hyperemic response was also studied for 6 min. Control angiography was performed at 1.5+/-0.8 year. Differences within groups were tested with a paired t-test and between groups with an unpaired t-test. Control angiography showed in 13 patients (group I) a patent LIMA graft and in 3 patients (group II) a string sign LIMA graft. Preoperative blood velocities were not significantly different between groups. Postoperatively, both groups revealed higher diastolic and lower systolic blood velocities compared to preoperative values. The blood velocities at rest did not change in group I and all velocities decreased in group II in time postoperatively. The blood velocities in maximal hyperemic response increased significantly within the groups and were not significantly different between the groups. No ischemia could be detected electrocardiographically during hyperemic response and no patient presented angina. Both groups showed a shift towards coronary type diastolic blood velocities at rest and at hyperaemic response. Significant hyperemic response was also present in string sign LIMA grafts and demonstrates response capacity to increased myocardial oxygen demand.

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

History of research in Japan on electrocardiography in the racehorse

PubMed Central

HIRAGA, Atsushi; SUGANO, Shigeru

2015-01-01

ABSTRACT Since the first recording of electrocardiograms (ECGs) of a horse in Japan was carried out in 1944, studies on ECGs have been performed intensively. During the early stages of research from the 1950s to 1960s, leads to use for ECG recording were evaluated using several different approaches including unipolar leads, bipolar limb leads, and bipolar chest leads. Based on these studies, the AB lead, which is oriented along the long axis of the heart, became the standard reference method in Japan. Electrodes of the AB lead are placed on the upper 1/4th point along a straight line between the withers and the left shoulder blade (base: B), and 10 cm posterior to the left olecranon (apex: A). The incidence of equine arrhythmias among racehorses has been surveyed, and details of the electrocardiographic characteristics of several arrhythmias have been investigated. In particular, atrial fibrillation (AF) has been extensively studied, and papers have reported findings such as that paroxysmal AF occurs during racing and described electrocardiographic changes that occur at the onset of AF during exercise. Development of a radiotelemetry system for ECG recording enabled the first recording of equine ECGs during galloping in 1964, the detection of arrhythmias, and calculation of heart rate during exercise. Studies on comparative and developmental changes of ECGs have described characteristics of the equine ECGs. Future research on changes in cardiac function, including autonomic function, that occur with aging may lead to new developments in equine electrocardiography and contribute to improving the health and welfare of the horse. PMID:25829865

The analysis of QT interval and repolarization morphology of the heart in chronic exposure to lead.

PubMed

Kiełtucki, J; Dobrakowski, M; Pawlas, N; Średniawa, B; Boroń, M; Kasperczyk, S

2017-10-01

There are no common recommendations regarding electrocardiographic monitoring in occupationally exposed workers. Therefore, the present study was designed to investigate whether exposure to lead results in an increase of selected electrocardiography (ECG) pathologies, such as QT interval prolongation and repolarization disorders, in occupationally exposed workers. The study group included 180 workers occupationally exposed to lead compounds. The exposed group was divided according to the median of the mean blood lead level (PbB mean ) calculated based on a series of measurements performed during 5-year observation period (35 µg/dl) into two subgroups: low exposure (LE, PbB mean = 20.0-35.0 µg/dl) and high exposure (HE, PbB mean = 35.1-46.4 µg/dl). The control group consisted of 69 healthy workers without occupational exposure to lead. ECG evaluation included the analysis of heart rate (HR), QT interval and repolarization abnormalities. Mean QT interval was significantly greater in the exposed population than in the control group by 2%. In the HE group, mean QT interval was significantly greater than in the control group by 4% and significantly different from those noted in the LE group. Positive correlations between QT interval and lead exposure indices were also reported. Besides, there was a negative correlation between HR and blood lead level. Increased concentration of lead in the blood above 35 μg/dl is associated with the QT interval prolongation, which may trigger arrhythmias when combined with other abnormalities, such as long QT syndrome. Therefore, electrocardiographic evaluation should be a part of a routine monitoring of occupationally exposed populations.

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.

A Unique Digital Electrocardiographic Repository for the Development of Quantitative Electrocardiography and Cardiac Safety: The Telemetric and Holter ECG Warehouse (THEW)

PubMed Central

Couderc, Jean-Philippe

2010-01-01

The sharing of scientific data reinforces open scientific inquiry; it encourages diversity of analysis and opinion while promoting new research and facilitating the education of next generations of scientists. In this article, we present an initiative for the development of a repository containing continuous electrocardiographic information and their associated clinical information. This information is shared with the worldwide scientific community in order to improve quantitative electrocardiology and cardiac safety. First, we present the objectives of the initiative and its mission. Then, we describe the resources available in this initiative following three components: data, expertise and tools. The Data available in the Telemetric and Holter ECG Warehouse (THEW) includes continuous ECG signals and associated clinical information. The initiative attracted various academic and private partners whom expertise covers a large list of research arenas related to quantitative electrocardiography; their contribution to the THEW promotes cross-fertilization of scientific knowledge, resources, and ideas that will advance the field of quantitative electrocardiography. Finally, the tools of the THEW include software and servers to access and review the data available in the repository. To conclude, the THEW is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. It is a new repository designed to complement the existing ones such as Physionet, the AHA-BIH Arrhythmia Database, and the CSE database. The THEW hosts unique datasets from clinical trials and drug safety studies that, so far, were not available to the worldwide scientific community. PMID:20863512

Pharmacokinetics of intravenously and orally administered sotalol hydrochloride in horses and effects on surface electrocardiogram and left ventricular systolic function.

PubMed

Broux, B; De Clercq, D; Decloedt, A; De Baere, S; Devreese, M; Van Der Vekens, N; Ven, S; Croubels, S; van Loon, G

2016-02-01

Arrhythmias are common in horses. Some, such as frequent atrial or ventricular premature beats, may require long-term anti-arrhythmic therapy. In humans and small animals, sotalol hydrochloride (STL) is often used for chronic oral anti-arrhythmic therapy. STL prolongs repolarization and the effective refractory period in all cardiac tissues. No information on STL pharmacokinetics or pharmacodynamics in horses is available and the aim of this study was to evaluate the pharmacokinetics of intravenously (IV) and orally (PO) administered STL and the effects on surface electrocardiogram and left ventricular systolic function. Six healthy horses were given 1 mg STL/kg bodyweight either IV or PO. Blood samples to determine plasma STL concentrations were taken before and at several time points after STL administration. Electrocardiography and echocardiography were performed at different time points before and after IV STL administration. Mean peak plasma concentrations after IV and PO administration of STL were 1624 ng/mL and 317 ng/mL, respectively. The oral bioavailability was intermediate (48%) with maximal absorption after 0.94 h, a moderate distribution and a mean elimination half-life of 15.24 h. After IV administration, there was a significant increase in QT interval, but no significant changes in other electrocardiographic and echocardiographic parameters. Transient transpiration was observed after IV administration, but no adverse effects were noted after a single oral dose of 1 mg/kg STL in any of the horses. It was concluded that STL has an intermediate oral bioavailability in the horse and might be useful in the treatment of equine arrhythmias. Copyright © 2015 Elsevier Ltd. All rights reserved.

[4D-MRI using the synchronized sampling method (SSM)].

PubMed

Shimada, Yasuhiro; Fujimoto, Ichirou; Takemoto, Hironori; Takano, Sayoko; Masaki, Shinobu; Honda, Kiyoshi; Takeo, Kazuhiro

2002-12-01

A synchronized sampling method (SSM) was developed for the study of voluntary movements by combining the electrocardiographic (ECG) gating method with an external triggering device, and four-dimensional magnetic resonance imaging (4D-MRI) at a rate of 30 frames per second was accomplished by volumetric imaging with the SSM. This method was first applied to the motion imaging of articulatory organs during repetitions of a Japanese five-vowel sequence, and the dynamic change in vocal tract area function was demonstrated with sufficient temporal resolution. This paper describes the methodology, applicability, and limitations of 4D-MRI with the SSM.

Signal separation by nonlinear projections: The fetal electrocardiogram

NASA Astrophysics Data System (ADS)

Schreiber, Thomas; Kaplan, Daniel T.

1996-05-01

We apply a locally linear projection technique which has been developed for noise reduction in deterministically chaotic signals to extract the fetal component from scalar maternal electrocardiographic (ECG) recordings. Although we do not expect the maternal ECG to be deterministic chaotic, typical signals are effectively confined to a lower-dimensional manifold when embedded in delay space. The method is capable of extracting fetal heart rate even when the fetal component and the noise are of comparable amplitude. If the noise is small, more details of the fetal ECG, like P and T waves, can be recovered.

Minimal pneumothorax with dynamic changes in ST segment similar to myocardial infarction.

PubMed

Yeom, Seok-Ran; Park, Sung-Wook; Kim, Young-Dae; Ahn, Byung-Jae; Ahn, Jin-Hee; Wang, Il-Jae

2017-08-01

Pneumothorax can cause a variety of electrocardiographic changes. ST segment elevation, which is mainly observed in myocardial infarction, can also be induced by pneumothorax. The mechanism is presumed to be a decrease in cardiac output, due to increased intra-thoracic pressure. We encountered a patient with ST segment elevation with minimal pneumothorax. Coronary angiography with ergonovine provocation test and echocardiogram had normal findings. The ST segment elevation was normalized by decreasing the amount of pneumothorax. We reviewed the literature and present possible mechanisms for this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Technetium-99m Pyrophosphate: Comparison of ED50 for Tetany and Acidosis with Acute LD500

DTIC Science & Technology

electrocardiogram and chemical analysis revealed that the hypocalcemic effect occurs at a much lower dosage than for the LD50. Polyphosphate was found to be more...toxic by the LD50 analysis than pyrophosphate. It is emphasized that the hypocalcemic toxic effects should be the determining factor in deciding what...to 1 with regard to the first signs of hypocalcemia by electrocardiographic measurements (i.e., 2 mg/kg). On this basis an injection of no more than 1 mg/kg is recommended to maintain a safety factor of around 10 to 1.

Biomedical engineering tasks. [electrode development for electrocardiography and electroencephalography

NASA Technical Reports Server (NTRS)

1972-01-01

Electrocardiographic and vectorcardiographic bioinstrumentation work centered on the development of a new electrode system harness for Project Skylab. Evaluation of several silver electrode configurations proved superior impedance voltage performance for silver/silver chloride electrodes mounted flush by using a paste adhesive. A portable ECG processor has been designed and a breadboard unit has been built to sample ECG input data at a rate of 500 samples per second for arrhythmia detection. A small real time display driver program has been developed for statistical analysis on selected QPS features. Engineering work on a sleep monitoring cap assembly continued.

Freeware eLearning Flash-ECG for learning electrocardiography.

PubMed

Romanov, Kalle; Kuusi, Timo

2009-06-01

Electrocardiographic (ECG) analysis can be taught in eLearning programmes with suitable software that permits the effective use of basic tools such as a ruler and a magnifier, required for measurements. The Flash-ECG (Research & Development Unit for Medical Education, University of Helsinki, Finland) was developed to enable teachers and students to use scanned and archived ECGs on computer screens and classroom projectors. The software requires only a standard web browser with a Flash plug-in and can be integrated with learning environments (Blackboard/WebCT, Moodle). The Flash-ECG is freeware and is available to medical teachers worldwide.

Potassium toxicity at low serum potassium levels with refeeding syndrome.

PubMed

Vemula, Praveen; Abela, Oliver G; Narisetty, Keerthy; Rhine, David; Abela, George S

2015-01-01

Refeeding syndrome is a life-threatening condition occurring in severely malnourished patients after initiating feeding. Severe hypophosphatemia with reduced adenosine triphosphate production has been implicated, but little data are available regarding electrolyte abnormalities. In this case, we report electrocardiographic changes consistent with hyperkalemia during potassium replacement after a serum level increase from 1.9 to 2.9 mEq/L. This was reversed by lowering serum potassium back to 2.0 mEq/L. In conclusion, the patient with prolonged malnutrition became adapted to low potassium levels and developed potassium toxicity with replacement. Copyright © 2015 Elsevier Inc. All rights reserved.

[Electrocardiographic diagnosis: when QRS is wide.

PubMed

Conti, Matilde; Bregani, Enrico Rino

2018-04-01

Differential diagnosis of one or more wide QRS complexes on an electrocardiogram under emergency conditions takes into account three main sets of clinical conditions: ventricular pre-excitation, aberrant conduction and ventricular beats and it is based on the morphological analysis of the ECG and patient's anamnestic data. Several criteria can facilitate the differential diagnosis and if properly used and integrated with clinic data they can achieve good diagnostic accuracy in most cases. In this review several criteria based on evidence and literature are presented, paying attention in recognizing some morphologic pathways that can be used in emergency room and allow a correct ECG assessment.

Innovative Varied-Fidelity Simulation Mobile Teaching Cart and Education Project.

PubMed

Harding, Andrew D; Cullinane Whalen, Kathryn; Silverman, Bradley S

2015-09-01

The use of a varied-fidelity simulation mobile teaching cart is a teaching tool that offers unique advantages in the acute care setting. The cart is used to demonstrate the use of patient monitoring devices, and there are a variety of software tools available with the monitoring technology to ensure that the outputs, including electrocardiographic waves, are analyzed appropriately by nursing staff using this varied-fidelity simulation mobile teaching cart. Bringing varied-fidelity simulation to the nurses' work area is a unique application setting. Copyright © 2015 Emergency Nurses Association. Published by Elsevier Inc. All rights reserved.

DDD pacemaker for severe heart failure-alternate to CRT.

PubMed

Krishnamani, N C

Patients with severe systolic Heart Failure continue to have poor quality of life and increased mortality in spite of optimal medical management. Cardiac Resynchronization Therapy [CRT] is promising modality in patients with systolic heart failure and electrocardiographic [ECG] evidence of left bundle branch block [LBBB]. Cost issues continue to elude many deserving cases of this therapy in our society. Relatively cost effective Dual chamber pacing [DDD] with right atrial and isolated left ventricular pacing [RA-LV] can be a good alternative. Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Imaging of pannus formation in patients with mechanical heart valves.

PubMed

Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-11-26

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.

Imaging of pannus formation in patients with mechanical heart valves

PubMed Central

Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-01-01

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients. PMID:26635931

Mesalamine hypersensitivity and Kounis syndrome in a pediatric ulcerative colitis patient

PubMed Central

Kounis, George N; Kouni, Sophia A; Hahalis, George; Kounis, Nicholas G

2008-01-01

5-aminosalicylic acid (mesalamine) rarely induces hypersensitivity reactions. If chest pain associated with atypical electrocardiographic changes are seen during its administration, one should always bear in mind typeIvariant of Kounis syndrome. This variant includes patients, of any age, with normal coronary arteries, without predisposing factors for coronary artery disease, in whom the acute release of inflammatory mediators from mast cells can induce either sudden coronary artery narrowing, without increase of cardiac enzymes and troponins, or coronary artery spasm that progresses to acute myocardial infarction, with elevated cardiac enzymes and troponins. PMID:19084925

Effect of Head-Down Bed Rest and Artificial Gravity Countermeasure on Cardiac Autonomic and Advanced Electrocardiographic Function

NASA Technical Reports Server (NTRS)

Schlegel, T. T.; Platts, S.; Stenger, M.; Ribeiro, C.; Natapoff, A.; Howarth, M.; Evans, J.

2007-01-01

To study the effects of 21 days of head-down bed rest (HDBR), with versus without an artificial gravity (AG) countermeasure, on cardiac autonomic and advanced electrocardiographic function. Fourteen healthy men participated in the study: seven experienced 21 days of HDBR alone ("HDBR controls") and seven the same degree and duration of HDBR but with approximately 1hr daily short-arm centrifugation as an AG countermeasure ("AG-treated"). Five minute supine high-fidelity 12-lead ECGs were obtained in all subjects: 1) 4 days before HDBR; 2) on the last day of HDBR; and 3) 7 days after HDBR. Besides conventional 12-lead ECG intervals and voltages, all of the following advanced ECG parameters were studied: 1) both stochastic (time and frequency domain) and deterministic heart rate variability (HRV); 2) beat-to-beat QT interval variability (QTV); 3) T-wave morphology, including signal-averaged T-wave residua (TWR) and principal component analysis ratios; 4) other SAECG-related parameters including high frequency QRS ECG and late potentials; and 5) several advanced ECG estimates of left ventricular (LV) mass. The most important results by repeated measures ANOVA were that: 1) Heart rates, Bazett-corrected QTc intervals, TWR, LF/HF power and the alpha 1 of HRV were significantly increased in both groups (i.e., by HDBR), but with no relevant HDBR*group differences; 2) All purely "vagally-mediated" parameters of HRV (e.g., RMSSD, HF power, Poincare SD1, etc.), PR intervals, and also several parameters of LV mass (Cornell and Sokolow-Lyon voltages, spatial ventricular activation times, ventricular gradients) were all significantly decreased in both groups (i.e., by HDBR), but again with no relevant HDBR*group differences); 3) All "generalized" or "vagal plus sympathetic" parameters of stochastic HRV (i.e., SDNN, total power, LF power) were significantly more decreased in the AG-treated group than in the HDBR-only group (i.e., here there was a relevant HDBR*group difference); and 4) QTV index was also significantly more changed (increased) in the AG-treated group than in the HDBR-only group, although this was clearly due to a greater decrease in generalized HRV and not to a greater increase in QTV proper because there was no relevant HDBR*group effect for either the SDNN or the RMSSD of QTV. Brief daily AG treatment by short-arm centrifuge during each of 21 days of HDBR does not appear to protect against HDBR-related losses of cardiac autonomic function or of LV mass as estimated by ECG.

Noninvasive detection of coronary artery bypass graft patency by intravenous electron beam computed tomographic angiography.

PubMed

Yamakami, Shoji; Toyama, Junji; Okamoto, Mitsuhiro; Matsushita, Toyoaki; Murakami, Yoshimasa; Ogata, Masaki; Ito, Shigenori; Fukutomi, Tatsuya; Okayama, Naotsuka; Itoh, Makoto

2003-11-01

This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion.

Electrocardiographic abnormalities and relative bradycardia in patients with hantavirus-induced nephropathia epidemica.

PubMed

Kitterer, Daniel; Greulich, Simon; Grün, Stefan; Segerer, Stephan; Mustonen, Jukka; Alscher, M Dominik; Braun, Niko; Latus, Joerg

2016-09-01

Nephropathia epidemica (NE), caused by Puumala virus (PUUV), is characterized by acute kidney injury (AKI) and thrombocytopenia. Cardiac involvement with electrocardiographic (ECG) abnormalities has been previously reported in NE; however, its prognostic value is unknown. Relative bradycardia is an important clinical sign in various infectious diseases, and previous smaller studies have described pulse-temperature deficit in patients with PUUV infection. We performed a cross-sectional survey of 471 adult patients with serologically confirmed NE. Data were collected retrospectively from medical records and prospectively at follow-up visits. Patients for whom ECGs were recorded during the acute phase of disease were enrolled retrospectively (n=263). Three patients were excluded because of documented pre-existing ECG abnormalities prior to NE. All patients with ECG abnormalities during the acute phase underwent follow-up. A total of 46 patients had ECG abnormalities at the time of admission to hospital (18%). T-wave inversion was the most frequent ECG abnormality (n=31 patients), followed by ST segment changes (nine patients with elevation and six with depression). No major adverse cardiac events occurred during follow-up (median 37months; range 34-63months). Of note, ECG abnormalities reverted to normal in the majority of the patients during follow-up. During the acute phase of NE, 149 of 186 patients had relative bradycardia, without implications for disease course. Transient ECG abnormalities were detected in 18% of patients during acute NE but were not associated with negative cardiovascular outcome. Relative bradycardia was identified in 80% of the patients with acute NE. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Impact of vasomotion type on prognosis of coronary artery spasm induced by acetylcholine provocation test of left coronary artery.

PubMed

Lee, Eun Mi; Choi, Man Ho; Seo, Hong Seog; Kim, Hyun Ki; Kim, Nam-Ho; Choi, Cheol Ung; Kim, Jin Won; Lim, Hong Euy; Kim, Eung Ju; Rha, Seung-Woon; Park, Chang Gyu; Oh, Dong Joo

2017-02-01

The impact of vasomotion types on long-term clinical outcomes in patients with coronary artery spasm (CAS) induced by the acetylcholine provocation test (ACH-test) remains unclear. We evaluated 4644 consecutive patients with typical resting chest pain (CP), but no angiographically significant coronary artery lesion (<50% stenosis), who underwent an ACH-test. According to their vasomotor response, patients were categorized into four types: normal vasomotion (no CP, no ischemic electrocardiographic changes, and no vasoconstriction), microvascular spasm (CP with <75% vasoconstriction but with CP relief after nitroglycerin infusion), epicardial spasm (CP with ≥75% vasoconstriction), and ACH-test inconclusive (vasoconstriction and/or electrocardiographic changes, but no CP). We investigated CP recurrence requiring follow-up angiography and major adverse cardiovascular events (MACEs) during 5 years. CP recurred in 7.9% of patients and was more frequent in abnormal vasomotion types (normal vasomotion, microvascular spasm, epicardial spasm, and inconclusive type: 5.4%, 9.8%, 10.9%, and 8.2%, respectively, log-rank p = 0.009). In multivariate analysis adjusted for medication use after the ACH-test, vasomotion subtype was not an independent predictor, whereas male sex, fixed lesion on baseline angiography, and medications including calcium channel blockers (CCBs), nitrates, and statins were independent positive predictors for recurrent CP. Alcohol consumption at the initial interview was a negative predictor. MACEs were observed in 1.6%, and the incidence was similar among subtypes (p = 0.421). Recurrent CP and long-term outcomes are independent of vasomotion subtypes, but long-term use of CCBs, nitrates, and statins is a significant predictor for recurrent CP. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Risk management of QT-prolonging drugs by community pharmacists using a mobile electrocardiograph].

PubMed

Shinozaki, Kohki

2010-11-01

Prolongation of the QT interval is associated with a high risk of serious arrhythmia, i.e., torsades de pointes (TdP). However, in many cases, the QT-prolonging drug(s) is prescribed without performing a thorough check-up of the patient's condition, especially an electrocardiogram. In addition to patient interview, we used an electrocardiogram obtained with a mobile electrocardiograph (RMH-ECG) in a community pharmacy in order to improve the risk management for QT-prolonging drugs. A comparison of the results obtained using RMH-ECG (modified I) and 12-lead ECG (I) revealed that both corrected QT (QTc) values were almost identical, and the correlation coefficient was 0.96. In one month, 5 of 948 patients who visited our pharmacy and continuously took QT-prolonging drugs had additional risk factors for TdP (advanced age, female, and drug-drug interaction). We monitored the QT interval of one of these patients. She had received erythromycin for 19 months along with other drugs metabolized by a P450 (CYP3A4); benidipine and prednisolone (for over 2 years), and tacrolimus (for 13 weeks). Three RMH-ECG tests at every 2 weeks revealed that QTcs were normal (0.43-0.45 s); therefore, we dispensed drugs without any change in the prescription. Approximately 1 in 1200 individuals has a prolonged QT interval without any subjective symptoms, and the time window of drug-induced TdP is considered to be from several hours to months after taking these drugs. Therefore, we think that an ECG test should be performed in community pharmacies before dispensing QT-prolonging drugs and that the QT interval should be monitored.

Pyruvate stabilizes electrocardiographic and hemodynamic function in pigs recovering from cardiac arrest

PubMed Central

Cherry, Brandon H; Nguyen, Anh Q; Hollrah, Roger A; Williams, Arthur G; Hoxha, Besim; Olivencia-Yurvati, Albert H

2015-01-01

Cardiac electromechanical dysfunction may compromise recovery of patients who are initially resuscitated from cardiac arrest, and effective treatments remain elusive. Pyruvate, a natural intermediary metabolite, energy substrate, and antioxidant, has been found to protect the heart from ischemia-reperfusion injury. This study tested the hypothesis that pyruvate-enriched resuscitation restores hemodynamic, metabolic, and electrolyte homeostasis following cardiac arrest. Forty-two Yorkshire swine underwent pacing-induced ventricular fibrillation and, after 6 min pre-intervention arrest, 4 min precordial compressions followed by transthoracic countershocks. After defibrillation and recovery of spontaneous circulation, the pigs were monitored for another 4 h. Sodium pyruvate or NaCl were infused i.v. (0.1 mmol·kg−1·min−1) throughout precordial compressions and the first 60 min recovery. In 8 of the 24 NaCl-infused swine, the first countershock converted ventricular fibrillation to pulseless electrical activity unresponsive to subsequent countershocks, but only 1 of 18 pyruvate-treated swine developed pulseless electrical activity (relative risk 0.17; 95% confidence interval 0.13–0.22). Pyruvate treatment also lowered the dosage of vasoconstrictor phenylephrine required to maintain systemic arterial pressure at 15–60 min recovery, hastened clearance of excess glucose, elevated arterial bicarbonate, and raised arterial pH; these statistically significant effects persisted up to 3 h after sodium pyruvate infusion, while infusion-induced hypernatremia subsided. These results demonstrate that pyruvate-enriched resuscitation achieves electrocardiographic and hemodynamic stability in swine during the initial recovery from cardiac arrest. Such metabolically based treatment may offer an effective strategy to support cardiac electromechanical recovery immediately after cardiac arrest. PMID:26088865

Evaluation of Tp-Te Interval and Tp-Te/QT Ratio in Patients with Coronary Slow Flow Tp-Te/QT Ratio and Coronary Slow Flow.

PubMed

Tenekecioglu, Erhan; Karaagac, Kemal; Yontar, Osman Can; Agca, Fahriye Vatansever; Ozluk, Ozlem Arican; Tutuncu, Ahmet; Arslan, Burhan; Yilmaz, Mustafa

2015-06-01

Coronary slow flow (CSF) phenomenon is described by angiographically normal coronary arteries with delayed opacification of the distal vasculature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-Te) may correspond to the transmural dispersion of the repolarization and that increased Tp-Te interval and Tp-Te/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate the ventricular repolarization by using Tp-Te interval and Tp-Te/QT ratio in patients with CSF. This study included 50 CSF patients (40 male, mean age 48.6±12.5 years) and 40 control individuals (23 male, mean age 47.8±12.5 years). Tp-Te interval and Tp-Te/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared in groups. Baseline characteristics of the study groups were comparable. In electrocardiographic parameters analysis, QT and corrected QT were similar in CSF patients compared to the controls (357±35.2 vs 362±38.0 milliseconds and 419±25.8 vs 430±44.2 milliseconds, all p value >0.05). Tp-Te interval, Tp-Te/QT and Tp-Te/QTc ratio were significantly higher in CSF patients (85±13.7 vs 74±9.9 milliseconds and 0.24±0.03 vs 0.20±0.02 and 0.20±0.03 vs 0.17±0.02 all p value <0.001). Our study revealed that QTd, Tp-Te interval and Tp-Te/QT ratio are prolonged in patients with CSF.

Wellens' syndrome and other electrocardiographic changes in a patient with a left anterior descending artery subocclusion associated with a left main coronary artery subocclusion.

PubMed

Patanè, Salvatore; Marte, Filippo

2011-09-01

Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. Patients with unstable angina have a higher incidence of left main coronary artery (LMCA) and proximal left anterior descending (LAD) coronary artery disease compared to patients with stable angina pectoris. In 1982, Wellens and colleagues described two electrocardiographic patterns that were predictive of critical narrowing of the proximal LAD artery, and were subsequently termed Wellens' syndrome. The criteria were: a) prior history of chest pain, b) little or no cardiac enzyme elevation, c) no pathologic precordial ST segment elevation, d) no loss of precordial R waves, and e) biphasic T waves in leads V2 and V3, or asymmetric, often deeply inverted T waves in leads V2 and V3. The ECG changes are best recognized outside the episode of anginal pain. Lead aVR and lead v1 ST segment elevation, during chest pain, has been reported in patients with LMCA disease with ST segment depression in leads V3, V4 and V5 (with maximal depression in V4).We present a case of changing axis deviation in a 37-year-old Italian man with a LAD coronary artery subocclusion associated with a LMCA subocclusion. This case focuses attention on the importance of the recognition of the patterns suspected for LAD coronary artery disease or for LMCA disease. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Infarct-like acute myocarditis: relation between electrocardiographic findings and myocardial damage as assessed by cardiac magnetic resonance imaging.

PubMed

Nucifora, Gaetano; Miani, Daniela; Di Chiara, Antonio; Piccoli, Gianluca; Artico, Jessica; Puppato, Michela; Slavich, Gianaugusto; De Biasio, Marzia; Gasparini, Daniele; Proclemer, Alessandro

2013-03-01

Acute myocarditis (AM) may occasionally have an infarct-like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique. Myocardial damage may be associated with ECG changes in infarct-like AM. Forty-one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct-like presentation were included. The relation between site of ST-segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated. Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P < 0.001), normalization of STE >24 hours (β = 0.39, P < 0.001), and development of negative T wave (β = 0.49, P < 0.001) were independently related to %LV LGE. Analysis of the site of STE underestimates the extent of myocardial injury among patients with infarct-like myocarditis. However, some ECG features (ie, sumSTE, normalization of STE >24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage. © 2012 Wiley Periodicals, Inc.

[Intelligent systems tools in the diagnosis of acute coronary syndromes: A systemic review].

PubMed

Sprockel, John; Tejeda, Miguel; Yate, José; Diaztagle, Juan; González, Enrique

2017-03-27

Acute myocardial infarction is the leading cause of non-communicable deaths worldwide. Its diagnosis is a highly complex task, for which modelling through automated methods has been attempted. A systematic review of the literature was performed on diagnostic tests that applied intelligent systems tools in the diagnosis of acute coronary syndromes. A systematic review of the literature is presented using Medline, Embase, Scopus, IEEE/IET Electronic Library, ISI Web of Science, Latindex and LILACS databases for articles that include the diagnostic evaluation of acute coronary syndromes using intelligent systems. The review process was conducted independently by 2 reviewers, and discrepancies were resolved through the participation of a third person. The operational characteristics of the studied tools were extracted. A total of 35 references met the inclusion criteria. In 22 (62.8%) cases, neural networks were used. In five studies, the performances of several intelligent systems tools were compared. Thirteen studies sought to perform diagnoses of all acute coronary syndromes, and in 22, only infarctions were studied. In 21 cases, clinical and electrocardiographic aspects were used as input data, and in 10, only electrocardiographic data were used. Most intelligent systems use the clinical context as a reference standard. High rates of diagnostic accuracy were found with better performance using neural networks and support vector machines, compared with statistical tools of pattern recognition and decision trees. Extensive evidence was found that shows that using intelligent systems tools achieves a greater degree of accuracy than some clinical algorithms or scales and, thus, should be considered appropriate tools for supporting diagnostic decisions of acute coronary syndromes. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

The prevalence of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 different dog breeds.

PubMed

Rudling, E H; Schlamowitz, S; Pipper, C B; Nilsson, E; Höllmer, M; Willesen, J L; Berendt, M; Fredholm, M; Gulløv, C H; Christiansen, M; Koch, J

2016-03-01

To investigate the prevalence and amplitudes of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 other dog breeds. Electrocardiograms from 206 healthy dogs representing 11 dog breeds were included in the study. Besides Petit Basset Griffon Vendéen (PBGV; n = 23) 10 other dog breeds were included. An electrocardiogram ruler was used for measuring the amplitudes of the J waves. The definition of a J wave was a positive deflection at the J point of ≥0.1 mV in more than 1 lead of the bipolar standard limb leads (I, II, III) or the unipolar standard limb leads (aVL and aVF). The prevalence of J waves in the PBGV (n = 23) was 91% (n = 21, standard error (SE) = 5.9%), which was significantly higher compared to seven other dog breeds (p < 0.05). The overall prevalence of J waves in all 11 dog breeds (n = 206) was 43% (n = 89, robust SE = 7.8%). There was no significant difference in the prevalence between male and female dogs (p = 0.79). Neither did age (p = 0.22) nor heart rate (p = 0.25) significantly affect the prevalence of J wave. The PBGV had the highest prevalence of J waves and the highest amplitudes compared to 10 other dog breeds. However J waves were also seen in other breeds. Therefore, J waves may be considered a normal variant on the canine electrocardiogram and should not be interpreted as cardiac disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Estimating personal exposures from ambient air-pollution measures: Using meta-analysis to assess measurement error

PubMed Central

Holliday, Katelyn M; Avery, Christy L; Poole, Charles; McGraw, Kathleen; Williams, Ronald; Liao, Duanping; Smith, Richard L; Whitsel, Eric A

2014-01-01

Background Although ambient concentrations of particulate matter ≤10μm (PM10) are often used as proxies for total personal exposure, correlation (r) between ambient and personal PM10 concentrations varies. Factors underlying this variation and its effect on health outcome-PM exposure relationships remain poorly understood. Methods We conducted a random-effects meta-analysis to estimate effects of study, participant and environmental factors on r; used the estimates to impute personal exposure from ambient PM10 concentrations among 4,012 non-smoking, diabetic participants in the Women’s Health Initiative clinical trial; and then estimated the associations of ambient and imputed personal PM10 concentrations with electrocardiographic measures such as heart rate variability. Results We identified fifteen studies (in years 1990-2009) of 342 participants in five countries. The median r was 0.46 (range = 0.13 to 0.72). There was little evidence of funnel-plot asymmetry but substantial heterogeneity of r, which increased 0.05 (95% confidence interval [CI]= 0.01 to 0.09) per 10 μg/m3 increase in mean ambient PM10 concentration. Substituting imputed personal exposure for ambient PM10 concentrations shifted mean percent changes in electrocardiographic measures per 10μg/m3 increase in exposure away from the null and decreased their precision, e.g. −2.0% (95% CI= −4.6% to 0.7%) versus −7.9% (−15.9% to 0.9%) for the standard deviation of normal-to-normal RR interval duration. Conclusions Analogous distributions and heterogeneity of r in extant meta-analyses of ambient and personal PM2.5 concentrations suggest that observed shifts in mean percent change and decreases in precision may be generalizable across particle size. PMID:24220191

New system for digital to analog transformation and reconstruction of 12-lead ECGs.

PubMed

Kothadia, Roshni; Kulecz, Walter B; Kofman, Igor S; Black, Adam J; Grier, James W; Schlegel, Todd T

2013-01-01

We describe initial validation of a new system for digital to analog conversion (DAC) and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer's 12-lead ECG hardware/software into that of any other. To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long) in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data. The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer's analog to digital converter (ADC) as the original digitization, and 28.4 µV per channel when it involved a different manufacturer's ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout. Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud-based servers.

P-Wave Indices and Risk of Ischemic Stroke: A Systematic Review and Meta-Analysis.

PubMed

He, Jinli; Tse, Gary; Korantzopoulos, Panagiotis; Letsas, Konstantinos P; Ali-Hasan-Al-Saegh, Sadeq; Kamel, Hooman; Li, Guangping; Lip, Gregory Y H; Liu, Tong

2017-08-01

Atrial cardiomyopathy is associated with an increased risk of ischemic stroke. P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area are electrocardiographic parameters that have been used to assess left atrial abnormalities related to developing atrial fibrillation. The aim of this systematic review and meta-analysis was to examine their values for predicting ischemic stroke risk. PubMed and EMBASE databases were searched until December 2016 for studies that evaluated the association between P-wave indices and stroke risk. Both fixed- and random-effects models were used to calculate the overall effect estimates. Ten studies examining P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area were included. P-wave terminal force in lead V 1 was found to be an independent predictor of stroke as both a continuous variable (odds ratio [OR] per 1 SD change, 1.18; 95% confidence interval [CI], 1.12-1.25; P <0.0001) and categorical variable (OR, 1.59; 95% CI, 1.10-2.28; P =0.01). P-wave duration was a significant predictor of incident ischemic stroke when analyzed as a categorical variable (OR, 1.86; 95% CI, 1.37-2.52; P <0.0001) but not when analyzed as a continuous variable (OR, 1.05; 95% CI, 0.98-1.13; P =0.15). Maximum P-wave area also predicted the risk of incident ischemic stroke (OR per 1 SD change, 1.10; 95% CI, 1.04-1.17). P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area are useful electrocardiographic markers that can be used to stratify the risk of incident ischemic stroke. © 2017 American Heart Association, Inc.

Clinical and electrocardiographic characteristics for prediction of new-onset atrial fibrillation in asymptomatic patients with atrial premature complexes.

PubMed

Im, Sung Il; Park, Dong Hyun; Kim, Bong Joon; Cho, Kyoung Im; Kim, Hyun Su; Heo, Jung Ho

2018-06-01

Identification of precursors of atrial fibrillation (AF) may lead to early detection and prevent associated morbidity and mortality. Atrial premature complexes (APCs) are commonly seen in healthy subjects. However, there was limited data about the clinical and electrocardiographic (ECG) characteristics for prediction of new-onset AF in asymptomatic patients with APCs in the long-term follow up. The Kosin University (No. 2014-02-04) 24-h holter monitoring, echocardiography, ECG database were reviewed from 2008 to 2016 to identify new- onset AF in patients with APCs. We analyzed demographic and clinical features and the nature of the APCs by ECG according to new-onset AF in those patients. Among 652 patients who underwent 24-h holter monitoring, 226 (34.4%) patients had new-onset AF. There was no difference of the baseline characteristics between new-onset AF group and non-AF group. In univariate analysis, hypertension (HTN), renal failure (CRF), high APC burdens, fastest APC running heart rate (HR), minimal HR, left ventricular ejection fraction (LVEF), left atrial volume index, peak mitral flow velocity of the early rapid filling wave and tricuspid regurgitation grade were significantly associated with new-onset AF. In multivariate analysis, higher APCs burden ( P  = 0.047), higher fastest APCs running HR ( P  = 0.034) and lower minimal HR ( P  = 0.025) were independent risk factors for new-onset AF in asymptomatic patients with APCs. Higher APCs burden, higher fastest APCs running HR and lower minimal HR were associated with new-onset AF in asymptomatic patients with APCs in the long-term follow up.

Evaluation of heart rate changes: electrocardiographic versus photoplethysmographic methods

NASA Technical Reports Server (NTRS)

Low, P. A.; Opfer-Gehrking, T. L.; Zimmerman, I. R.; O'Brien, P. C.

1997-01-01

The heart rate (HR) variation to forced deep breathing (HRDB) and to the Valsalva maneuver (Valsalva ratio; VR) are the two most widely used tests of cardiovagal function in human subjects. The HR is derived from a continuously running electrocardiographic (ECG) recording. Recently, HR derived from the arterial waveform became available on the Finapres device (FinapHR), but its ability to detect rapid changes in HR remains uncertain. We therefore evaluated HRDB and VR derived from FinapHR using ECG-derived HR (ECGHR) recordings as the standard. We also compared the averaged HR on Finapres (Finapav) with beat-to-beat Finapres (FinapBB) values. Studies were undertaken in 12 subjects with large HR variations: age, 34.5 +/- 9.3 (SD) years; six males and six females. FinapBB values were superimposable upon ECGHR for both HRDB and VR. In contrast, Finapav failed to follow ECGHR for HRDB and followed HRECG with a lag for the VR. To evaluate statistically how closely FinapHR approximated ECGHR, we undertook regression analysis, using mean values for each subject. To compare the two methods, we evaluated the significance of the difference between test and standard values. For HRDB, FinapBB reproducibly recorded HR (R2 = 0.998), and was significantly (p = 0.001) better than Finapav (R2 = 0.616; p < 0.001). For VR, HRBB generated a VR that was not significantly different from the correct values, while HRav generated a value that was slightly but consistently lower than the correct values (p < 0.001). We conclude that FinapHR reliably records HR variations in the beat-to-beat mode for cardiovascular HR tests.

United States national prevalence of electrocardiographic abnormalities in black and white middle-age (45- to 64-Year) and older (≥65-Year) adults (from the Reasons for Geographic and Racial Differences in Stroke Study).

PubMed

Prineas, Ronald J; Le, Anh; Soliman, Elsayed Z; Zhang, Zhu-Ming; Howard, Virginia J; Ostchega, Yechiam; Howard, George

2012-04-15

A United States national sample of 20,962 participants (57% women, 44% blacks) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study provided general population estimates for electrocardiographic (ECG) abnormalities among black and white men and women. The participants were recruited from 2003 to 2007 by random selection from a commercially available nationwide list, with oversampling of blacks and those from the stroke belt, with a cooperation rate of 49%. The measurement of risk factors and 12-lead electrocardiograms (centrally coded using Minnesota code criteria) showed 28% had ≥1 major ECG abnormality. The prevalence of abnormalities was greater (≥35%) for those ≥65 years old, with no differences between blacks and whites. However, among men <65 years, blacks had more major abnormalities than whites, most notably for atrial fibrillation, major Q waves, and left ventricular hypertrophy. Men generally had more ECG abnormalities than women. The most common ECG abnormalities were T-wave abnormalities. The average heart rate-corrected QT interval was longer in women than in men, similar in whites and blacks, and increased with age. However, the average heart rate was greater in women than in men and in blacks than in whites and decreased with age. The prevalence of ECG abnormalities was related to the presence of hypertension, diabetes, blood pressure, and age. In conclusion, black men and women in the United States have a significantly greater prevalence of ECG abnormalities than white men and women at age 45 to 64 years; however, these proportions, although larger, tended to equalize or reverse after age 65. Copyright © 2012 Elsevier Inc. All rights reserved.

Cardio-respiratory responses of the 6-minute walk test in patients with refractory heart failure during the preoperative period for heart transplant surgery.

PubMed

Gerson, Cipriano; Bernardelli, Graziella França; Arena, Ross; Oliveira, Luis Vicente Franco; Valdez, Francisco; Branco, João Nelson Rodrigues

2010-06-01

The six-minute walk test (6MWT) has been used to assess functional capacity, clinical status and prognosis. There are a very few descriptions in the literature on the safety and metabolic impact of the test, especially in patients with severe heart failure, awaiting cardiac transplantation. The aim of the present study was to assess the cardiovascular responses and correlate the performance on the 6MWT with clinical status. From 15 initial candidates, twelve patients (10 males) aged 52 +/- 8 years were submitted to a comprehensive clinical evaluation. The patients performed the 6MWT with electrocardiographic and perceived exertion monitoring in addition to determination of blood lactate concentration. Patients were followed up for 12 months. The patients walked 399.4 +/- 122.5 meters, reaching a perceived exertion (PE) of 14.3 +/- 1.5 and an increase of 34% in resting heart rate. Two patients exhibited a greater severity of arrhythmia prior to the 6MWT, which did not increase during exertion. Four patients exhibited a significant increase in blood lactate levels (>5 mmol/dL) and three interrupted the test prematurely. The distance walked (D) revealed a correlation with the ejection fraction (%) and functional classification (NYHA). After 12 months of follow up, three patients died and seven were re-hospitalized due to heart failure decompensation. Clinical and electrocardiographic behavior suggests that the 6MWT is safe, but may be considered of high intensity for some patients with severe heart failure. Variables related to the performance on the 6MWT may be associated to worsening clinical status in this population.

Association of Trypanosoma cruzi infection with risk factors and electrocardiographic abnormalities in northeast Mexico

PubMed Central

2014-01-01

Background American trypanosomiasis is a major disease and public health issue, caused by the protozoan parasite Trypanosoma cruzi. The prevalence of T. cruzi has not been fully documented, and there are few reports of this issue in Nuevo Leon. The aim of this study was to update the seroprevalence rate of T. cruzi infection, including an epidemiological analysis of the risk factors associated with this infection and an electrocardiographic (ECG) evaluation of those infected. Methods Sera from 2,688 individuals from 10 municipalities in the state of Nuevo Leon, Mexico, were evaluated using an enzyme-linked immunosorbent assay and an indirect hemagglutination assay. An ECG case–control study was performed in subjects seropositive for T. cruzi and the results were matched by sex and age to seronegative residents of the same localities. A univariate analysis with χ2 and Fisher’s exact tests was used to determine the association between seropositivity and age (years), sex, and ECG changes. A multivariate analysis was then performed to calculate the odd ratios between T. cruzi seropositivity and the risk factors. Results The seropositive rate was 1.93% (52/2,688). In the ECG study, 22.85% (8/35) of the infected individuals exhibited ECG abnormalities. Triatoma gerstaeckeri was the only vector reported. The main risk factors were ceiling construction material (P ≤ 0.0024), domestic animals (P ≤ 0.0001), and living in rural municipalities (P ≤ 0.0025). Conclusions These findings demonstrate a 10-fold higher prevalence of Chagas disease than previously reported (0.2%), which implies a serious public health threat in northeastern Mexico. The epidemiological profile established in this study differs from that found in the rest of Mexico, where human populations live in close proximity to domiciliary triatomines. PMID:24580840

Weight fluctuation, mortality and vascular disease in Pima Indians.

PubMed

Hanson, R L; Jacobsson, L T; McCance, D R; Narayan, K M; Pettitt, D J; Bennett, P H; Knowler, W C

1996-05-01

To examine the relationship of weight fluctuation to mortality rates and incidence of vascular disease. A cohort of Pima Indians, 572 of whom had non-insulin-dependent diabetes mellitus and 766 without diabetes. Individuals were invited biennially to research examinations. The root mean square error (RMSE) of the linear trend of weight with time for the first four examinations after age 20 years was used as an index of weight fluctuation. Subjects were followed from the fourth examination until death or until 31 December 1991. The mortality rate ratio (MRR) and its 95% confidence interval (CI) for those with a high weight fluctuation index relative to those with a lower value were determined. The median duration of follow up was 9.3 (range 0.1-22.6) years. All cause mortality (n = 356); incidence of diabetic retinopathy (n = 145), diabetic nephropathy (n = 132) and electrocardiographic abnormalities (n = 82). There was no significant relationship between weight fluctuation and mortality for diabetic subjects (MRR = 1.0, 95% CI 0.8-1.3, p = 0.91). Nondiabetic subjects with a high weight fluctuation index had a higher mortality rate than those with a lower index (MRR = 1.5, 95% CI 1.0-2.1, p = 0.03); the association was stronger among men than among women. The excess mortality in the high weight fluctuation group was not due to cardiovascular diseases, but to noncardiovascular causes and the risk for alcohol-related death was particularly increased. Weight fluctuation was not associated with the incidence of diabetic retinopathy, nephropathy or electrocardiographic abnormalities. A high weight fluctuation index was associated with higher mortality rates in nondiabetic, but not in diabetic, Pima Indians. The excess mortality is largely due to noncardiovascular causes of death and may reflect lifestyle factors associated with weight fluctuation, rather than its metabolic effects.

Electrocardiographic and blood pressure effects of energy drinks and Panax ginseng in healthy volunteers: A randomized clinical trial.

PubMed

Shah, Sachin A; Occiano, Andrew; Nguyen, Tinh An; Chan, Amanda; Sky, Joseph C; Bhattacharyya, Mouchumi; O'Dell, Kate M; Shek, Allen; Nguyen, Nancy N

2016-09-01

Energy drink usage has been linked to emergency room visits and deaths. The objective of the study is to assess the electrocardiographic and blood pressure effects of energy drinks, Panax ginseng and placebo in healthy individuals. This was a randomized, double blinded, placebo controlled, crossover study. Young healthy volunteers with no comorbid conditions consumed 32oz of an energy drink, control drink with 800mg of Panax ginseng or matching placebo-control drink over 45min. Primary endpoints were QTc interval and systolic blood pressure. Secondary endpoints included QT interval, PR interval, QRS duration, heart rate, and diastolic blood pressure. All endpoints were assessed at baseline, 1, 2, 3.5, and 5.5h. A significant increase in QTc interval 2h post energy drink consumption was evident when compared to placebo (3.37±10.7ms and -3.19±11.8ms respectively; p=0.030). Similarly, systolic blood pressure 2h post energy drink consumption increased when compared to placebo (2.00±6.37mmHg and -2.67±5.83mmHg respectively; p=0.014). The PR interval significantly reduced over a 2h period post energy drink use in a clinically non-meaningful manner. Heart rate at 2h was not significantly higher in the energy drink group when compared to others. The QT interval, QRS interval and diastolic blood pressure were not impacted at any time point. Certain energy drinks consumed at a high volume significantly increase the QTc interval and systolic blood pressure by over 6ms and 4mmHg respectively. Panax ginseng does not have a significant impact on ECG or blood pressure parameters. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Electrocardiographic abnormalities in acute olanzapine poisonings].

PubMed

Ciszowski, Krzysztof; Sein Anand, Jacek

2011-01-01

Olanzapine is an atypical antipsychotic used for many years in the treatment of schizophrenia and bipolar disorder. Poisonings with this medicine can results with cardiotoxic effects in the form of ECG abnormalities. To evaluate the nature and incidence of electrocardiographic abnormalities in patients with acute olanzapine poisoning. 23 adult (mean age 38.4 +/- 15.5 years) patients with acute olanzapine poisoning, including 10 men (30.4 +/- 8.1 years) and 11 women (45.7 +/- 17.2 years), where 1 man and 1 woman were poisoned twice. The toxic serum level of olanzapine (above 100 ng/mL) was confirmed in each patient. Evaluation of electrocardiograms performed in patients in the first day of hospitalization with automatic measurement of durations of PQ, QRS and QTc and the identification of arrhythmias and conduction disorders on the basis of visual analysis of the ECG waveforms. Statistical analysis of the results using the methods of descriptive statistics. The mean durations of PQ, QRS and QTc in the study group were as follows: 135 +/- 23 ms, 91 +/- 12 ms, and 453 +/- 48 ms, respectively. The most common ECG abnormalities were prolonged QTc and supraventricular tachycardia (including sinus tachycardia) - each 22%; less common were ST-T changes (17%) and supraventricular premature complexes (9%), and only in individual cases (4%) ventricular premature complexes, bundle branch block, sinus bradycardia and atrial fibrillation were present. In the course of acute olanzapine poisonings: (1) prolonged QTc interval is quite common, but rarely leads to torsade de pointes tachycardia; (2) fast supraventricular rhythms are also common, but rarely cause irregular tachyarrhythmias, eg. atrial fibrillation; (3) conduction disorders (atrioventricular blocks, bundle branch blocks) are not typical abnormalities; (4) the observed ECG abnormalities emphasize the need of continuous ECG monitoring in these patients.

Association of Implementation of Practice Standards for Electrocardiographic Monitoring With Nurses' Knowledge, Quality of Care, and Patient Outcomes: Findings From the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial.

PubMed

Funk, Marjorie; Fennie, Kristopher P; Stephens, Kimberly E; May, Jeanine L; Winkler, Catherine G; Drew, Barbara J

2017-02-01

Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses' knowledge, quality of care, and patient outcomes. The PULSE (Practical Use of the Latest Standards of Electrocardiography) Trial was a 6-year multisite randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, time 2 after group 1 hospitals received the intervention, and time 3 after group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses' knowledge (N=3013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest; N=95 884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses' knowledge improved significantly immediately after the intervention in both groups but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention and was sustained. Online ECG monitoring education and strategies to change practice can lead to improved nurses' knowledge, quality of care, and patient outcomes. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01269736. © 2017 American Heart Association, Inc.

Electrocardiographic Criteria for Left Ventricular Hypertrophy in Asians Differs from Criteria Derived from Western Populations--Community-based Data from an Asian Population.

PubMed

Xu, Chang Fen; Tan, Eugene S J; Feng, Liang; Santhanakrishnan, Rajalakshmi; Chan, Michelle M Y; Nyunt, Shwe Zin; Ng, Tze Pin; Ling, Lieng Hsi; Richards, A Mark; Lam, Carolyn S P; Lim, Toon Wei

2015-08-01

Electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH), such as the Cornell and Sokolow-Lyon voltage criteria were derived from Western populations. However, their utility and accuracy for diagnosing echocardiographic LVH in Asian populations is unclear. The objective of this study was to assess the accuracy of ECG criteria for LVH in Asians and to determine if alternative gender-specific ECG cut-offs may improve its diagnostic accuracy. ECG and echocardiographic assessments were performed on 668 community-dwelling Asian adults (50.9% women; 57 ± 10 years) in Singapore. The accuracy of ECG voltage criteria was compared to echocardiographic LVH criteria based on the American Society of Echocardiography guidelines, and Asian ethnicity and gender-specific partition values. Echocardiographic LVH was present in 93 (13.6%) adults. Cornell criteria had low sensitivity (5.5%) and high specificity (98.9%) for diagnosing LVH. Modified gender specific cut-offs (18 mm in women, 22 mm in men) improved sensitivity (8.8% to 17.5%, 0% to 14.7%, respectively) whilst preserving specificity (98.2% to 94.2%, 100% to 95.8%). Similarly, Sokolow-Lyon criteria had poor sensitivity (7.7%) and high specificity (96.1%) for diagnosing LVH. Lowering the cut-off value from 35 mm to 31 mm improved the sensitivity in women from 3.5% to 14% while preserving specificity at 94.2%. A cut-off of 36 mm was optimal in men (sensitivity of 14.7%, specificity of 95.5%). Current ECG criteria for LVH derived in Western cohorts have limited sensitivity in Asian populations. Our data suggests that ethnicity- and gender-specific ECG criteria may be needed.

Electrocardiographic characteristics of left ventricular outflow tract tachycardia.

PubMed

Hachiya, H; Aonuma, K; Yamauchi, Y; Harada, T; Igawa, M; Nogami, A; Iesaka, Y; Hiroe, M; Marumo, F

2000-11-01

Catheter ablation of idiopathic left ventricular outflow tract tachycardia (LVOT-VT) is rare because a safe ablation technique at this site has not been described, and serious complications may occur. This study compared the QRS morphology of LVOT-VT with that of idiopathic right ventricular outflow tract tachycardia. A comparison was made between the electrocardiographic characteristics of LVOT-VT originating from the supravalvular region of a coronary cusp (Supra-Ao group) with those of LVOT-VT originating from the infravalvular endocardial region of a coronary cusp of the aortic valve within the LV (Infra-Ao group). After precise mapping of the right ventricle, left ventricle, pulmonary artery, coronary cusps, and proximal portion of the anterior interventricular vein, there were 17 patients in whom VT was thought to be located at the LVOT by both activation and pace mapping. They were divided between a Supra-Ao group (n = 8), and an Infra-Ao group (n = 9). Analysis of the 12-lead electrocardiogram (ECG) revealed an S wave in lead I in all 17 patients. A precordial R wave transition was also observed at V1 or V2 in 16 patients (94%). In 7 of 8 patients (88%) with Supra-Ao LVOT-VT, no S wave was observed in either V5 or V6. In contrast, an Rs pattern was observed in both V5 and V6, or in V6 only, in 100% of the patients with Infra-Ao LVOT-VT. A LVOT-VT should be suspected when the ECG shows an S wave in lead I and an R/S ratio greater than 1 in lead V1 or V2, versus a coronary cusp location if there is no S wave in either lead V5 or V6.

The Use of Continuous Electrocardiographic Holter Monitoring in Pediatric Cardiology

PubMed Central

Begic, Zijo; Begic, Edin; Mesihovic-Dinarevic, Senka; Masic, Izet; Pesto, Senad; Halimic, Mirza; Kadic, Almira; Dobraca, Amra

2016-01-01

Objective: To show the place and role of continuous electrocardiographic twenty-four-hour ECG monitoring in daily clinical practice of pediatric cardiologists. Methods: According to protocol, 2753 patients underwent dynamic continuous ECG Holter monitoring (data collected from the “Register of ECG Holter monitoring” of Pediatric Clinic, UCC Sarajevo in period April 2003- April 2015). Results: There were 50,5% boys and 49,5% girls, aged from birth to 19 years (1,63% - neonates and infants, 2,6% - toddlers, 9,95% - preschool children, 35,5% - gradeschoolers and 50,3% children in puberty and adolescence). In 68,1% of patients Holter was performed for the first time. Indications for conducting Holter were: arrhythmias in 42,2% cases, precordial pain in 23,5%, suspicion of pre-excitation and/or pre-excitation in 10%, crisis of consciousness in 8%, uncorrected congenital/acquired heart defects in 4,2%, operated heart defects in 3,7%, hypertension in 3,1% cases, control of the pacemaker in 1,63% and other causes in 3,5% cases. Discharge diagnosis after ECG Holter monitoring were: insignificant arrhythmias in 47,1% cases, wandering pacemaker in 21,3%, pre-excitation in 16,2%, benign ventricular premature beats in 6,3%, atrioventricular block in 3%, sinus pause in 2.2% cases and other arrhythmias in 3,5%. In mentioned period 57 cases of Wolf Parkinson White syndrome were registered, in 4,5% of patients antiarrhythmic therapy was administered. Radiofrequent ablation was performed in 23 cases. Conclusion: The development of pediatric cardiac surgery has initiated development of pediatric arrhythmology as imperative segment of pediatric cardiology. Continuous ECG Holter monitoring has become irreplaceable method in everyday diagnostics and therapy of arrhythmias in children. PMID:27708487

[Evaluation of Slavic continuity for electrocardiograph (ECG)-gated non-helical scan using multi detector-row computed tomography with 64 data acquisition system].

PubMed

Shiotani, Masataka; Ogawa, Masato; Watanabe, Ryo; Shinohara, Tamotsu

2012-01-01

Multi detector-row computed tomography with 64 data acquisition systems are widely used for coronary CT angiography with an electrocardiograph (ECG) gated helical scan (HS). Step and shoot with ECG gated non-helical scan (snap shot pulse: SSP) could reduce exposure dose but banding artifact-like discontinuity was observed between adjacent slabs on volume rendering (VR) and curved planner reconstruction (CPR). Therefore, we investigated the factors that influence continuity of VR and CPR images by calculating image properties of Z-axis direction of slab. The observer performance studies were performed for evaluating continuity of simulated blood vessels of VR and CPR images at simulated heart rates: 50, 55, 57 and 60 beat per minute (bpm). As a result, the value of SD at both slab edges in SSP were 20.5% lower than middle part of slab and differences of value of SD were up to 4.4 between adjacent slab edges. Slice thickness of both slab edges were 20.3% thinner than that of the peripheral part of slab. At the border of the adjacent slab, the position of the simulated blood vessel was shifted. VR images of SSP at 57 bpm was indicated as the highest score and HS was significantly superior to SSP at 55 and 60 bpm (p<0.05). In CPR images, there were no significant differences at all simulated heart rates. In conclusion, we considered that VR images of SSP were influenced heart rates except 57 bpm (resonance case) and there was little difference of visibility for discontinuity of both CPR images obtained by SSP and HS.

Left ventricular hypertrophy index based on a combination of frontal and transverse planes in the ECG and VCG: Diagnostic utility of cardiac vectors

NASA Astrophysics Data System (ADS)

Bonomini, Maria Paula; Juan Ingallina, Fernando; Barone, Valeria; Antonucci, Ricardo; Valentinuzzi, Max; Arini, Pedro David

2016-04-01

The changes that left ventricular hypertrophy (LVH) induces in depolarization and repolarization vectors are well known. We analyzed the performance of the electrocardiographic and vectorcardiographic transverse planes (TP in the ECG and XZ in the VCG) and frontal planes (FP in the ECG and XY in the VCG) to discriminate LVH patients from control subjects. In an age-balanced set of 58 patients, the directions and amplitudes of QRS-complexes and T-wave vectors were studied. The repolarization vector significantly decreased in modulus from controls to LVH in the transverse plane (TP: 0.45±0.17mV vs. 0.24±0.13mV, p<0.0005 XZ: 0.43±0.16mV vs. 0.26±0.11mV, p<0.005) while the depolarization vector significantly changed in angle in the electrocardiographic frontal plane (Controls vs. LVH, FP: 48.24±33.66° vs. 46.84±35.44°, p<0.005, XY: 20.28±35.20° vs. 19.35±12.31°, NS). Several LVH indexes were proposed combining such information in both ECG and VCG spaces. A subset of all those indexes with AUC values greater than 0.7 was further studied. This subset comprised four indexes, with three of them belonging to the ECG space. Two out of the four indexes presented the best ROC curves (AUC values: 0.78 and 0.75, respectively). One index belonged to the ECG space and the other one to the VCG space. Both indexes showed a sensitivity of 86% and a specificity of 70%. In conclusion, the proposed indexes can favorably complement LVH diagnosis

Office and Home Blood Pressures as Determinants of Electrocardiographic Left Ventricular Hypertrophy Among Black Nigerians Compared With White Flemish

PubMed Central

Odili, Augustine N; Thijs, Lutgarde; Yang, Wen-Yi; Ogedengbe, John O; Nwegbu, Maxwell M; Jacobs, Lotte; Wei, Fang-Fei; Feng, Ying-Mei; Zhang, Zhen-Yu; Kuznetsova, Tatiana; Nawrot, Tim S; Staessen, Jan A

2017-01-01

Abstract BACKGROUND The association of electrocardiographic left ventricular hypertrophy (ECG-LVH) with blood pressure (BP) in Blacks living in sub-Saharan Africa remains poorly documented. METHODS In 225 Black Nigerians and 729 White Flemish, we analyzed QRS voltages and voltage-duration products and 12 criteria diagnostic of ECG-LVH in relation to office BP (mean of 5 consecutive readings) and home BP (duplicate morning and evening readings averaged over 1 week). RESULTS In multivariable analyses, QRS voltage and voltage-duration indexes were generally higher in Blacks than Whites. By using any of 12 criteria, ECG-LVH was more prevalent among Black than White men (54.4% vs. 36.0%) with no ethnic difference among women (17.1%). Precordial voltages and voltage-duration products increased with office and home systolic BP (SBP), and increases were up to 3-fold steeper in Blacks. In Blacks vs. Whites, increases in the Sokolow–Lyon voltage associated with a 10-mm Hg higher SBP were 0.18 mV (95% confidence interval [CI], 0.09–0.26) vs. 0.06 mV (0.02–0.09) and 0.17 mV (0.07–0.28) vs. 0.11 mV (CI, 0.07–0.15) for office and home BP, respectively, with a significant ethnic gradient (P < 0.05). The risk of ECG-LVH increased more with office and home BP in Blacks than Whites. CONCLUSIONS Associations of ECG voltages and voltage-duration products and risk of ECG-LVH with BP are steeper in Black Nigerians compared with a White reference population. In resource-poor settings of sub-Saharan Africa, the ECG in combination with office and home BP is an essential instrument in risk stratification across the entire BP range. PMID:29059302

A low-power and miniaturized electrocardiograph data collection system with smart textile electrodes for monitoring of cardiac function.

PubMed

Dai, Ming; Xiao, Xueliang; Chen, Xin; Lin, Haoming; Wu, Wanqing; Chen, Siping

2016-12-01

With the increasing aging population as well as health concerns, chronic heart disease has become the focus of public attention. A comfortable, low-powered, and wearable electrocardiogram (ECG) system for continuously monitoring the elderly's ECG signals over several hours is important for preventing cardiovascular diseases. Traditional ECG monitoring apparatus is often inconvenient to carry, has many electrodes to attach to the chest, and has a high-power consumption. There is also a challenge to design an electrocardiograph that satisfies requirements such as comfort, confinement, and compactness. Based on these considerations, this study presents a biosensor acquisition system for wearable, ubiquitous healthcare applications using three textile electrodes and a recording circuit specialized for ECG monitoring. In addition, several methods were adopted to reduce the power consumption of the device. The proposed system is composed of three parts: (1) an ECG analog front end (AFE), (2) digital signal processing and micro-control circuits, and (3) system software. Digital filter methods were used to eliminate the baseline wander, skin contact noise, and other interfering signals. A comparative study was conducted using this system to observe its performance with two commercial Holter monitors. The experimental results demonstrated that the total power consumption of this proposed system in a full round of ECG acquisition was only 29.74 mW. In addition, this low-power system performed well and stably measured the heart rate with an accuracy of 98.55 %. It can also contain a real-time dynamic display with organic light-emitting diodes (OLED) and wirelessly transmit information via a Bluetooth 4.0 module.

Tp-e Interval, Tp-e/QTc Ratio, and Fragmented QRS Are Correlated with the Severity of Liver Cirrhosis.

PubMed

Akboga, Mehmet Kadri; Yuksel, Mahmut; Balci, Kevser Gulcihan; Kaplan, Mustafa; Cay, Serkan; Gokbulut, Volkan; Yayla, Cagri; Ertem, Ahmet Goktug; Ayhan, Meral Akdogan; Topaloglu, Serkan; Aras, Dursun

2017-01-01

Arrhythmias and electrocardiographic changes are reported in several noncardiac diseases, including liver cirrhosis (LC). We intended to evaluate the interval from the peak to the end of the electrocardiographic T wave (Tp-e), Tp-e/QTc ratio, and fQRS as presumed markers of arrhythmias in LC. In this cross-sectional study, a total of 88 consecutive patients with LC according to clinical, biological, ultrasonographic, or histological criteria and 73 control subjects were enrolled. The severity of cirrhosis was classified according to Pugh-Child's classification and Model for End-Stage Liver Disease (MELD) score. Tp-e interval, Tp-e/QTc ratio, and fQRS rates were measured from the 12-lead electrocardiogram. Tp-e interval, Tp-e/QTc ratio and fQRS rates were significantly increased in parallel to the severity of LC (P < 0.001, P < 0.001, and P = 0.003, respectively). In correlation analysis, Pugh-Child stage showed a significantly positive correlation with Tp-e interval (r = 0.462, P < 0.001), QTc interval (r = 0.373, P < 0.001), Tp-e/QTc ratio (r = 0.352, P < 0.001), and fQRS (r = 0.407, P < 0.001). Furthermore, Tp-e interval (r = 0.414, P < 0.001) and Tp-e/QTc ratio (r = 0.426, P< 0.001) had significant positive correlation with MELD score. Our study demonstrated that Tp-e interval, Tp-e/QTc ratios, and fQRS rates were significantly increased in parallel to the severity of LC. Thus, these findings may implicate that Tp-e interval, Tp-e/QTc ratio, and fQRS may be novel and useful indicators for prediction of arrhythmias in LC. © 2016 Wiley Periodicals, Inc.

Reproducibility for Heart Rate Variability Analysis during 6-Min Walk Test in Patients with Heart Failure and Agreement between Devices.

PubMed

Braga, Lays Magalhães; Prado, Gustavo Faibischew; Umeda, Iracema Ioco Kikuchi; Kawauchi, Tatiana Satie; Taboada, Adriana Marques Fróes; Azevedo, Raymundo Soares; Pereira Filho, Horacio Gomes; Grupi, César José; Souza, Hayala Cristina Cavenague; Moreira, Dalmo Antônio Ribeiro; Nakagawa, Naomi Kondo

2016-01-01

Heart rate variability (HRV) analysis is a useful method to assess abnormal functioning in the autonomic nervous system and to predict cardiac events in patients with heart failure (HF). HRV measurements with heart rate monitors have been validated with an electrocardiograph in healthy subjects but not in patients with HF. We explored the reproducibility of HRV in two consecutive six-minute walk tests (6MW), 60-minute apart, using a heart rate monitor (PolarS810i) and a portable electrocardiograph (called Holter) in 50 HF patients (mean age 59 years, NYHA II, left ventricular ejection fraction ~35%). The reproducibility for each device was analysed using a paired t-test or the Wilcoxon signed-rank test. Additionally, we assessed the agreement between the two devices based on the HRV indices at rest, during the 6MW and during recovery using concordance correlation coefficients (CCC), 95% confidence intervals and Bland-Altman plots. The test-retest for the HRV analyses was reproducible using Holter and PolarS810i at rest but not during recovery. In the second 6MW, patients showed significant increases in rMSSD and walking distance. The PolarS810i measurements had remarkably high concordance correlation [0.86

Association of Implementation of Practice Standards for Electrocardiographic Monitoring with Nurses’ Knowledge, Quality of Care, and Patient Outcomes: Findings from the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial

PubMed Central

Funk, Marjorie; Fennie, Kristopher P.; Stephens, Kimberly E.; May, Jeanine L.; Winkler, Catherine G.; Drew, Barbara J.

2017-01-01

Background Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses’ knowledge, quality of care, and patient outcomes. Methods and Results The PULSE Trial was a 6-year multi-site randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, Time 2 after Group 1 hospitals received the intervention, and Time 3 after Group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses’ knowledge (N=3,013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4,587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest) (N=95,884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses’ knowledge improved significantly immediately following the intervention in both groups, but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention, and was sustained. Conclusions Online ECG monitoring education and strategies to change practice can lead to improved nurses’ knowledge, quality of care, and patient outcomes. PMID:28174175

Dissociation of hemodynamic and electrocardiographic indexes of myocardial ischemia in pigs with hibernating myocardium and sudden cardiac death.

PubMed

Pizzuto, Matthew F; Suzuki, Gen; Banas, Michael D; Heavey, Brendan; Fallavollita, James A; Canty, John M

2013-06-15

Many survivors of sudden cardiac death (SCD) have normal global ventricular function and severe coronary artery disease but no evidence of symptomatic ischemia or infarction before the development of lethal ventricular arrhythmias, and the trigger for ventricular tachycardia (VT)/ventricular fibrillation (VF) remains unclear. We sought to identify the role of spontaneous ischemia and temporal hemodynamic factors preceding SCD using continuous telemetry of left ventricular (LV) pressure and the ECG for periods up to 5 mo in swine (n = 37) with hibernating myocardium who experience spontaneous VT/VF in the absence of heart failure or infarction. Hemodynamics and ST deviation at the time of VT/VF were compared with survivors with hibernating myocardium as well as sham controls. All episodes of VT/VF occurred during sympathetic activation and were initiated by single premature ventricular contractions, and the VT degenerated into VF in ∼ 30 s. ECG evidence of ischemia was infrequent and no different from those that survived. Baseline hemodynamics were no different among groups, but LV end-diastolic pressure during sympathetic activation was higher at the time of SCD (37 ± 4 vs. 26 ± 4 mmHg, P < 0.05) and the ECG demonstrated QT shortening (155 ± 4 vs. 173 ± 5 ms, P < 0.05). The week before SCD, both parameters were no different from survivors. These data indicate that there are no differences in the degree of sympathetic activation or hemodynamic stress when VT/VF develops in swine with hibernating myocardium. The transiently elevated LV end-diastolic pressure and QT shortening preceding VT/VF raises the possibility that electrocardiographically silent subendocardial ischemia and/or mechanoelectrical feedback serve as a trigger for the development of SCD in chronic ischemic heart disease.

Role of electrocardiographic changes in discriminating acute or chronic right ventricular pressure overload.

PubMed

Can, Mehmet Mustafa; Özveren, Olcay; Biteker, Murat; Şengül, Cihan; Uz, Ömer; Işılak, Zafer; Kırılmaz, Ata

2013-06-01

Pulmonary embolism (PE) and severe pulmonary stenosis (PS) are two distinct conditions accompanied by increased pressure load of the right ventricle (RV). Despite major advances in our understanding of the mechanisms of RV adaptation to the increased pressure, substantial gaps in our knowledge remain unsettled. One of much less known aspect of pressure overload of RV is its impact on electrocardiographic (ECG) changes. In this study, we aimed to study whether acute and chronic RV overload are accompanied by different ECG patterns. Thirty-eight patients with PE underwent ECG monitoring were compared with 20 matched patients with PS in this observational retrospective study. ECG abnormalities suggestive of RV overload were recorded and analyzed in both groups. Logistic regression analysis was used to define the predictors of chronic RV overload. Among the ECG changes studied, premature atrial contraction (OR-12.2, 95% CI, 1.3-107, p=0.008), right axis deviation (OR-20.4, 95% CI 4.2-98, p<0.001), indeterminate axis (OR-0.11, 95% CI 0.02-0.44, p=0.001 0.11), incomplete right bundle branch block (OR-4.2, 95% CI, 1.1-15.4, p=0.02), late R in aVR (OR-8.4, 95% CI 2.1-33.2, p=0.001), qR in V1 lead (OR-8.3, 95% CI 1.2-74.8, p=0.03) were found to be the independent predictors of chronic RV pressure overload. Our data indicate that the ECG changes that attributed to the acute RV pressure loading states may be more prevalent in chronic RV overload as compared with acute RV overload.

Prognostic significance of electrocardiographic Q-waves in a low-risk population.

PubMed

Godsk, Peter; Jensen, Jan Skov; Abildstrøm, Steen Z; Appleyard, Merete; Pedersen, Sune; Mogelvang, Rasmus

2012-07-01

In individuals without known heart disease, electrocardiographic Q-waves predict a poor prognosis. We aimed to examine whether prognostic information can be derived from the size and location of Q-waves in persons from the general population without known ischaemic heart disease (IHD) or heart failure (HF). Electrocardiograms (ECGs) of 5381 persons without known IHD or HF from the 4th Copenhagen City Heart Study were reviewed and Q-waves were classified according to their size and location. Multivariate Cox proportional hazards regression models were used to examine the associations of Q-waves adjusted for age, hypertension, diabetes, and estimated glomerular filtration rate with the risk of the combined endpoint of death and hospitalization for IHD. During a median of 7.8 years of follow-up, 1003 persons reached the combined endpoint. One hundred and fourteen (2.1%) had pathological Q-waves, of whom 44% suffered from an event compared with 18% from the control group, P< 0.001. Persons with hypertension, diabetes, and impaired renal function were more likely to have Q-waves. Even small Q-waves (i.e. Minnesota code 1.2.x-1.3.x) were associated with a poor prognosis, hazard ratio (HR) 1.4 [95% confidence interval (CI): 1.0-2.0; P< 0.05], though not as grave as large Q-waves (i.e. Minnesota code 1.1.x) HR 2.8 (95%CI: 1.6-5.0; P< 0.001). Conversely, there was no difference in the outcome of patients with anteriorly HR 1.6 (95%CI: 1.1-2.4) vs. posteriorly HR 1.5 (95%CI: 0.9-2.4) located Q-waves (P= 0.85). In the general population without known IHD or HF, even small Q-waves in the ECG are associated with a poor prognosis.

[Relationship between electrocardiographic and genetic mutation (MYH7-H1717Q, MYLK2-K324E and KCNQ1-R190W) phenotype in patients with hypertrophic cardiomyopathy].

PubMed

Shao, Hong; Zhang, Yanmin; Liu, Liwen; Ma, Zhiling; Zuo, Lei; Ye, Chuang; Wei, Xiaomei; Sun, Chao; Tao, Ling

2016-01-01

To explore the relationship between electrocardiographic (ECG) and genetic mutations of patients with hypertrophic cardiomyopathy (HCM), and early ECG changes in HCM patients. Clinical, 12-lead ECG and echocardiographic examination as well as genetic examinations were made in a three-generation Chinses HCM pedigree with 8 family members (4 males). The clinical characterization and ECG parameters were analyzed and their relationship with genotypes in the family was explored. Four missense mutations (MYH7-H1717Q, MYLK2-K324E, KCNQ1-R190W, TMEM70-I147T) were detected in this pedigree. The proband carried all 4 mutations and 5 members carried 2 mutations. Corrected QTc interval of KCNQ1-H1717Q carriers was significantly prolonged and was consistent with the ECG characterization of long QT syndrome. MYLK2-K324E and KCNQ1-R190W carriers presented with Q wave and(or) depressed ST segment, as well as flatted or reversed T waves in leads from anterolateral and inferior ventricular walls. ECG results showed ST segment depression, flat and inverted T wave in the gene mutation carriers with normal echocardiographic examination results. ECG and echocardiographic results were normal in TMEM70-I147T mutation carrier. The combined mutations of the genes associated with cardiac ion channels and HCM are linked with the ECG phenotype changes in this HCM pedigree. The variations in ECG parameters due to the genetic mutation appear earlier than the echocardiography and clinical manifestations. Variation in ECG may become one of the indexes for early diagnostic screening and disease progression of the HCM gene mutation carriers.

Cardiac Mean Electrical Axis in Thoroughbreds—Standardization by the Dubois Lead Positioning System

PubMed Central

da Costa, Cássia Fré; Samesima, Nelson; Pastore, Carlos Alberto

2017-01-01

Background Different methodologies for electrocardiographic acquisition in horses have been used since the first ECG recordings in equines were reported early in the last century. This study aimed to determine the best ECG electrodes positioning method and the most reliable calculation of mean cardiac axis (MEA) in equines. Materials and Methods We evaluated the electrocardiographic profile of 53 clinically healthy Thoroughbreds, 38 males and 15 females, with ages ranging 2–7 years old, all reared at the São Paulo Jockey Club, in Brazil. Two ECG tracings were recorded from each animal, one using the Dubois lead positioning system, the second using the base-apex method. QRS complex amplitudes were analyzed to obtain MEA values in the frontal plane for each of the two electrode positioning methods mentioned above, using two calculation approaches, the first by Tilley tables and the second by trigonometric calculation. Results were compared between the two methods. Results There was significant difference in cardiac axis values: MEA obtained by the Tilley tables was +135.1° ± 90.9° vs. -81.1° ± 3.6° (p<0.0001), and by trigonometric calculation it was -15.0° ± 11.3° vs. -79.9° ± 7.4° (p<0.0001), base-apex and Dubois, respectively. Furthermore, Dubois method presented small range of variation without statistical or clinical difference by either calculation mode, while there was a wide variation in the base-apex method. Conclusion Dubois improved centralization of the Thoroughbreds' hearts, engendering what seems to be the real frontal plane. By either calculation mode, it was the most reliable methodology to obtain cardiac mean electrical axis in equines. PMID:28095442

Evaluation of left ventricular function using electrocardiographically gated myocardial SPECT with (123)I-labeled fatty acid analog.

PubMed

Nanasato, M; Ando, A; Isobe, S; Nonokawa, M; Hirayama, H; Tsuboi, N; Ito, T; Hirai, M; Yokota, M; Saito, H

2001-12-01

Electrocardiographically (ECG) gated myocardial SPECT with (99m)Tc-tetrofosmin has been used widely to assess left ventricular (LV) function. However, the accuracy of variables using ECG gated myocardial SPECT with beta-methyl-p-(123)I-iodophenylpentadecanoic acid (BMIPP) has not been well defined. Thirty-six patients (29 men, 7 women; mean age, 61.6 +/- 15.6 y) with ischemic heart disease underwent ECG gated myocardial SPECT with (123)I-BMIPP and with (99m)Tc-tetrofosmin and left ventriculography (LVG) within 1 wk. LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV) were determined on gated SPECT using commercially available software for automatic data analysis. These volume-related items on LVG were calculated with an area-length method and were estimated by 2 independent observers to evaluate interobserver validity. The regional wall motion with these methods was assessed visually. LVEF was 41.1% +/- 12.5% on gated SPECT with (123)I-BMIPP, 44.5% +/- 13.1% on gated SPECT with (99m)Tc-tetrofosmin, and 46.0% +/- 12.7% on LVG. Global LV function and regional wall motion between both gated SPECT procedures had excellent correlation (LVEF, r = 0.943; LVEDV, r = 0.934; LVESV, r = 0.952; regional wall motion, kappa = 0.92). However, the correlations of global LV function and regional wall motion between each gated SPECT and LVG were significantly lower. Gated SPECT with (123)I-BMIPP showed the same interobserver validity as gated SPECT with (99m)Tc-tetrofosmin. Gated SPECT with (123)I-BMIPP provides high accuracy with regard to LV function and is sufficiently applicable for use in clinical SPECT. This technique can simultaneously reveal myocardial fatty acid metabolism and LV function, which may be useful to evaluate various cardiac diseases.

Prognostic value of predischarge electrocardiographic measurement of infarct size after thrombolysis: insights from GUSTO I Economics and Quality of Life substudy.

PubMed

Barbagelata, Alejandro; Califf, Robert M; Sgarbossa, Elena B; Knight, David; Mark, Daniel B; Granger, Christopher B; Armstrong, Paul W; Elizari, Marcelo; Birnbaum, Yochai; Grinfeld, Liliana R; Ohman, E Magnus; Wagner, Galen S

2004-11-01

Current methods for risk stratification after acute myocardial infarction (MI) include several noninvasive studies. In this cost-containment era, the development of low-cost means should be encouraged. We assessed the ability of an electrocardiogram (ECG) MI-sizing score to predict outcomes in patients enrolled in the Economics and Quality of Life (EQOL) sub study of the Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries -I (GUSTO-I) trial. We classified patients by electrocardiographic Selvester QRS score at hospital discharge: those with a score 0-9 versus > or =10. Endpoints were 30-day and 1-year mortality, resource use, and quality-of-life measures. Patients with a QRS score <10 were well-matched with those with QRS score > or =10 with the exception of a trend to more anterior MI in the higher scored group. Patients with QRS score > or =10 had increased risk of death at 30-days (8.9% vs. 2.9% P < .001), and this difference persisted at 1 year (12.6% vs. 5.4%, P = .001). Recurrent chest pain, use of angiography, and angioplasty were similar during follow-up. However, there was a trend toward less coronary bypass surgery in patients with a QRS score > or =10. Readmission rates were higher at 30 days but similar at 1 year. Stratification of patients after acute MI by a simple measure of MI size identifies populations with different long-term prognoses; patients with a QRS score > or =10 (approximately 30% of the left ventricle infarcted) at discharge have poorer outcomes in both the short- and long-term. The standard 12-lead ECG provides a simple, economical means of risk stratification at discharge.

Electrophysiologic profile and results of invasive risk stratification in asymptomatic children and adolescents with the Wolff-Parkinson-White electrocardiographic pattern.

PubMed

Kubuš, Peter; Vít, Pavel; Gebauer, Roman A; Materna, Ondřej; Janoušek, Jan

2014-04-01

Data on the results and clinical effect of an invasive risk stratification strategy in asymptomatic young patients with the Wolff-Parkinson-White electrocardiographic pattern are scarce. Eighty-five consecutive patients aged<18 years with a Wolff-Parkinson-White pattern and persistent preexcitation at maximum exercise undergoing invasive risk stratification were retrospectively studied. Adverse accessory pathway (AP) properties were defined according to currently consented criteria as any of the following: shortest preexcited RR interval during atrial fibrillation/rapid atrial pacing≤250 ms (or antegrade effective refractory period≤250 ms if shortest preexcited RR interval was not available) or inducible atrioventricular re-entrant tachycardia. Age at evaluation was median 14.9 years. Eighty-two patients had a structurally normal heart and 3 had hypertrophic cardiomyopathy. A single manifest AP was present in 80, 1 manifest and 1 concealed AP in 4, and 2 manifest APs in 1 patient. Adverse AP properties were present in 32 of 85 patients (37.6%) at baseline and in additional 16 of 44 (36.4%) after isoproterenol. Ablation was performed in 41 of these 48 patients. Ablation was deferred in the remaining 7 for pathway proximity to the atrioventricular node. In addition, 18 of the low-risk patients were ablated based on patient/parental decision. Adverse AP properties at baseline were exhibited by 37.6% of the evaluated patients with an asymptomatic Wolff-Parkinson-White preexcitation persisting at peak exercise. Isoproterenol challenge yielded additional 36.4% of those tested at higher risk. Ablation was performed in a total of 69.4% of patients subjected to invasive risk stratification.

Cardiotoxicity of tricyclic antidepressant treated by 2650 mEq sodium bicarbonate: A case report.

PubMed

Amiri, Hassan; Zamani, Nasim; Hassanian-Moghaddam, Hossein; Shadnia, Shahin

2016-01-01

Poisoning with tricyclic antidepressants is an important cause of drug-related self-poisoning in the developed world and a very common cause of poisoning and mortality in developing countries. Electrocardiographic manifestations of most tricyclic antidepressant-poisoned patients resolve by the administration of 1-2 mEq/kg of sodium bicarbonate. Some rare cases have been reported who have been resistant to the long-term or high doses of bicarbonate administration. We present a case of acute tricyclic antidepressant toxicity referring with status epilepticus, hypotension, and refractory QRS complex widening that resolved after the intravenous administration of 2650 mEq sodium bicarbonate.

Electrocardiographic Biomarkers for Detection of Drug-Induced Late Sodium Current Block

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

Vicente, Jose; Johannesen, Lars; Hosseini, Meisam

Drugs that prolong the heart rate corrected QT interval (QTc) on the electrocardiogram (ECG) by blocking the hERG potassium channel and also block inward currents (late sodium or L-type calcium) are not associated with torsade de pointes (e.g. ranolazine and verapamil). Furthermore, identifying ECG signs of late sodium current block could aid in the determination of proarrhythmic risk for new drugs. A new cardiac safety paradigm for drug development (the "CiPA" initiative) will involve the preclinical assessment of multiple human cardiac ion channels and ECG biomarkers are needed to determine if there are unexpected ion channel effects in humans.

Electrocardiographic Biomarkers for Detection of Drug-Induced Late Sodium Current Block

DOE PAGES

Vicente, Jose; Johannesen, Lars; Hosseini, Meisam; ...

2016-12-30

Drugs that prolong the heart rate corrected QT interval (QTc) on the electrocardiogram (ECG) by blocking the hERG potassium channel and also block inward currents (late sodium or L-type calcium) are not associated with torsade de pointes (e.g. ranolazine and verapamil). Furthermore, identifying ECG signs of late sodium current block could aid in the determination of proarrhythmic risk for new drugs. A new cardiac safety paradigm for drug development (the "CiPA" initiative) will involve the preclinical assessment of multiple human cardiac ion channels and ECG biomarkers are needed to determine if there are unexpected ion channel effects in humans.

Risk of advanced heart block during extradural anaesthesia in patients with right bundle branch block and left anterior hemiblock.

PubMed

Coriat, P; Harari, A; Ducardonet, A; Tarot, J P; Viars, P

1981-05-01

Electrocardiographic recording by Holter monitoring demonstrated the absence of any modification, however minimal, of the intranodal conduction during surgical procedures under extradural anaesthesia in 20 patients with right bundle branch block (RBBB) and left anterior hemiblock (LAHB) but without symptoms. These data suggest that extradural anaesthesia can be used safely in patients with asymptomatic chronic RBBB and LAHB without prophylactic insertion of pacemakers. However, patients having experienced either syncope or transient Mobitz II second degree AV block are likely to have a trifascicular block and increased risk of advanced heart block during extradural anaesthesia.

Cardiovascular and hypokalaemic effects of inhaled salbutamol, fenoterol, and isoprenaline.

PubMed Central

Crane, J; Burgess, C; Beasley, R

1989-01-01

The cardiovascular and hypokalaemic effects of equal doses of inhaled fenoterol, isoprenaline and salbutamol were compared in eight healthy male volunteers, in a double blind, placebo controlled study. Increasing doses of 400, 600, and 800 micrograms were given from a metered dose inhaler at 15 minute intervals, followed by measurements of heart rate, blood pressure, total electromechanical systole (as a measure of inotropic response), QTc interval, and plasma potassium concentration. After repeated inhalation, fenoterol resulted in significantly greater chronotropic, electrocardiographic, and hypokalaemic effects than either isoprenaline or salbutamol. The maximum inotropic effect of fenoterol was similar to that of isoprenaline. PMID:2928998

RR-Interval variance of electrocardiogram for atrial fibrillation detection

NASA Astrophysics Data System (ADS)

Nuryani, N.; Solikhah, M.; Nugoho, A. S.; Afdala, A.; Anzihory, E.

2016-11-01

Atrial fibrillation is a serious heart problem originated from the upper chamber of the heart. The common indication of atrial fibrillation is irregularity of R peak-to-R-peak time interval, which is shortly called RR interval. The irregularity could be represented using variance or spread of RR interval. This article presents a system to detect atrial fibrillation using variances. Using clinical data of patients with atrial fibrillation attack, it is shown that the variance of electrocardiographic RR interval are higher during atrial fibrillation, compared to the normal one. Utilizing a simple detection technique and variances of RR intervals, we find a good performance of atrial fibrillation detection.

Unstable angina with normal coronary angiography in hyperthyroidism: a case report.

PubMed

Lin, Tsung-Hsien; Su, Ho-Ming; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2005-01-01

Hyperthyroidism is associated with an increase in myocardial oxygen consumption that, due to an imbalance of oxygen demand and supply, can cause angina. However, subclinical hyperthyroidism rarely presents as chest pain in the resting state. Herein, we present a case of subclinical hyperthyroidism involving a 58-year-old male who complained of frequent chest tightness and typical electrocardiographic changes while in a resting state. Coronary angiography showed no significant lesion. Laboratory data showed that the patient suffered from hyperthyroidism, for which he was successfully treated with anti-thyroid agents. We are reminded that typical chest pain might be the first symptom of hyperthyroidism.

A rare cause of acute coronary syndrome: Kounis syndrome.

PubMed

Almeida, João; Ferreira, Sara; Malheiro, Joana; Fonseca, Paulo; Caeiro, Daniel; Dias, Adelaide; Ribeiro, José; Gama, Vasco

2016-12-01

Kounis syndrome is an acute coronary syndrome in the context of a hypersensitivity reaction. The main pathophysiological mechanism appears to be coronary vasospasm. We report the case of a patient with a history of allergy to quinolones, who was given ciprofloxacin before an elective surgical procedure and during drug administration developed symptoms and electrocardiographic changes suggestive of ST-segment elevation acute coronary syndrome. The drug was suspended and coronary angiography excluded epicardial coronary disease. Two hours after withdrawal of the drug the symptoms and ST elevation had resolved completely. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Object-oriented analysis and design of an ECG storage and retrieval system integrated with an HIS.

PubMed

Wang, C; Ohe, K; Sakurai, T; Nagase, T; Kaihara, S

1996-03-01

For a hospital information system, object-oriented methodology plays an increasingly important role, especially for the management of digitized data, e.g., the electrocardiogram, electroencephalogram, electromyogram, spirogram, X-ray, CT and histopathological images, which are not yet computerized in most hospitals. As a first step in an object-oriented approach to hospital information management and storing medical data in an object-oriented database, we connected electrocardiographs to a hospital network and established the integration of ECG storage and retrieval systems with a hospital information system. In this paper, the object-oriented analysis and design of the ECG storage and retrieval systems is reported.

A portable system for acquiring and removing motion artefact from ECG signals

NASA Astrophysics Data System (ADS)

Griffiths, A.; Das, A.; Fernandes, B.; Gaydecki, P.

2007-07-01

A novel electrocardiograph (ECG) signal acquisition and display system is under development. It is designed for patients ranging from the elderly to athletes. The signals are obtained from electrodes integrated into a vest, amplified, digitally processed and transmitted via Bluetooth to a PC with a Labview ® interface. Digital signal processing is performed to remove movement artefact and electromyographic (EMG) noise, which severely distorts signal morphology and complicates clinical diagnosis. Independent component analysis (ICA) is also used to improve the signal quality. The complete system will integrate the electronics into a single module which will be embedded in the vest.

The 4th Report of the Working Group on ECG diagnosis of Left Ventricular Hypertrophy.

PubMed

Bacharova, Ljuba; Estes, Harvey E; Schocken, Douglas D; Ugander, Martin; Soliman, Elsayed Z; Hill, Joseph A; Bang, Lia E; Schlegel, Todd T

The 4th Report provides a brief review of publications focused on the electrocardiographic diagnosis of left ventricular hypertrophy published during the period of 2010 to 2016 by the members of the Working Group on ECG diagnosis of Left Ventricular Hypertrophy. The Working Group recommended that ECG research and clinical attention be redirected from the estimation of LVM to the identification of electrical remodeling, to better understanding the sequence of events connecting electrical remodeling to outcomes. The need for a re-definition of terms and for a new paradigm is also stressed. Copyright © 2016 Elsevier Inc. All rights reserved.

The development of insulated electrocardiogram electrodes

NASA Technical Reports Server (NTRS)

Portnoy, W. M.; David, R. M.

1971-01-01

An integrated system was developed, consisting of an insulated electrode and an impedance transformer, which can be used for the acquisition of electrocardiographic data. The electrode consists of a thin layer of dielectric material deposited onto a silicon substrate. The impedance transformer is an operational amplifier used in the unity gain configuration. Both electrode and impedance transformer are contained in a plastic housing identical to that used with the NASA Apollo-type electrode. The lower cut off frequency of the electrode system is between 0.01 and 1.0 Hz, depending on the dielectric used and its thickness. Clinical quality electrocardiograms were obtained with these electrodes.

Takotsubo Myocardiopathy and Hyperthyroidism: A Case Report and Literature Review

PubMed Central

Rueda, Darío; Aguirre, Rafael; Contardo, Damián; Finocchietto, Paola; Hernández, Silvia; di Fonzo, Horacio

2017-01-01

Patient: Male, 34 Final Diagnosis: Takotsubo myocardiopathy and hyperthyroidism Symptoms: Chest pain • dyspnea Medication: — Clinical Procedure: — Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Takotsubo cardiomyopathy (TM), also called stress myocardiopathy or transient left ventricular apical ballooning syndrome, is characterized by acute left ventricular dysfunction with reversible wall motion abnormalities. TM resembles acute coronary syndrome (ACS) in the absence of coronary artery disease (CAD). In several reports, TM has been described in association with hyperthyroidism, suggesting the potential role of thyrotoxicosis in the pathophysiology. Case Report: We present the case of a 34-year-old man with TM associated with hyperthyroidism caused by Graves’ disease. In this case, TM was also preceded by an emotional trigger. The diagnosis of TM was based on clinical manifestations, electrocardiographic and echocardiographic abnormalities, and the absence of coronary artery disease (CAD) in the angiography. A diagnosis of hyperthyroidism was made based on hormonal and antibody measurements. The patient had a favorable outcome, and the cardiac and thyroid disorders resolved. Conclusions: Our case illustrates that thyroid disease, mainly hyperthyroidism, should be considered in patients with TM with or without previous emotional triggers. As in our patient, the outcome in TM is usually favorable, with reversibility of cardiac abnormalities. PMID:28781361

A new approach for low-cost noninvasive detection of asymptomatic heart disease at rest.

PubMed

DeMarzo, Arthur P; Calvin, James E

2007-01-01

It would be useful to have an inexpensive, noninvasive point-of-care test for early detection of asymptomatic heart disease. This study used impedance cardiography (ICG) in a new way to assess heart function that did not use stroke volume or cardiac output. There is a model of the ICG dZ/dt waveform that may be used as a template to represent normal heart function. The hypothesis was that a dZ/dt waveform which deviates from that template should indicate heart dysfunction and therefore heart disease. The objective was to assess the accuracy of this new ICG approach, using echocardiography as the standard. Thirty-four outpatients undergoing echocardiographic testing were tested by ICG while sitting upright and supine. All patients had no symptoms or history of a structural or functional heart disorder. Echocardiographic testing showed 17 patients with abnormalities and 17 as normal. ICG testing yielded 16 true positives for heart dysfunction with 1 false negative (sensitivity = 94%) and 17 true negatives with no false positives (specificity = 100%). Considering that the cost, technical skill, and time required for this ICG test are comparable to those of an electrocardiograph, this new approach has potential as a point-of-care screening test for asymptomatic heart disease.

Noninvasive coronary artery angiography using electron beam computed tomography

NASA Astrophysics Data System (ADS)

Rumberger, John A.; Rensing, Benno J.; Reed, Judd E.; Ritman, Erik L.; Sheedy, Patrick F., II

1996-04-01

Electron beam computed tomography (EBCT), also known as ultrafast-CT or cine-CT, uses a unique scanning architecture which allows for multiple high spatial resolution electrocardiographic triggered images of the beating heart. A recent study has demonstrated the feasibility of qualitative comparisons between EBCT derived 3D coronary angiograms and invasive angiography. Stenoses of the proximal portions of the left anterior descending and right coronary arteries were readily identified, but description of atherosclerotic narrowing in the left circumflex artery (and distal epicardial disease) was not possible with any degree of confidence. Although these preliminary studies support the notion that this approach has potential, the images overall were suboptimal for clinical application as an adjunct to invasive angiography. Furthermore, these studies did not examine different methods of EBCT scan acquisition, tomographic slice thicknesses, extent of scan overlap, or other segmentation, thresholding, and interpolation algorithms. Our laboratory has initiated investigation of these aspects and limitations of EBCT coronary angiography. Specific areas of research include defining effects of cardiac orientation; defining the effects of tomographic slice thickness and intensity (gradient) versus positional (shaped based) interpolation; and defining applicability of imaging each of the major epicardial coronary arteries for quantitative definition of vessel size, cross-sectional area, taper, and discrete vessel narrowing.

Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

NASA Astrophysics Data System (ADS)

DeMarco, M.; Maggi, S.

2006-07-01

Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m-1 (E-field 400 V m-1). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy.

The emerging role of exercise testing and stress echocardiography in valvular heart disease.

PubMed

Picano, Eugenio; Pibarot, Philippe; Lancellotti, Patrizio; Monin, Jean Luc; Bonow, Robert O

2009-12-08

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future.

Mechanism and prognostic role of qR in V1 in patients with pulmonary arterial hypertension.

PubMed

Waligóra, Marcin; Kopeć, Grzegorz; Jonas, Kamil; Tyrka, Anna; Sarnecka, Agnieszka; Miszalski-Jamka, Tomasz; Urbańczyk-Zawadzka, Małgorzata; Podolec, Piotr

The presence of qR pattern in lead V 1 of the 12-lead surface ECG has been proposed as a risk marker of death in patients with pulmonary arterial hypertension (PAH). We aimed to validate these findings in the modern era of PAH treatment and additionally to assess the relation of qR in V 1 to PAH severity. We also investigated the possible mechanisms underlying this ECG sign. Consecutive patients with PAH excluding patients with congenital heart defect were recruited between February 2008 and January 2016. A 12-lead standard ECG was acquired and analyzed for the presence of qR in V 1 and other potential prognostic patterns. Cardiac magnetic resonance and echocardiography were used for structural (masses and volumes) and functional (ejection fraction, eccentricity index) characterization of left (LV) and right (RV) ventricles. Standard markers of PAH severity were also assessed. We enrolled 66 patients (19 males), aged 50.0±15.7years with idiopathic PAH (n=52) and PAH associated with connective tissue disease (n=14). qR in V 1 was present in 26(39.4%) patients and was associated with worse functional capacity, hemodynamics and RV function. The main structural determinants of qR in V 1 were RV to LV volume ratio (OR: 3.99; 95% CI: 1.47-10.8, p=0.007) and diastolic eccentricity index (OR: 15.0; 95% CI: 1.29-175.5, p=0.03). During observation time of 30.5±19.4months, 20 (30.3%) patient died, 13 (50%) patients with qR and 7 (17.5%) patients without qR pattern. Electrocardiographic determinants of survival were qR (HR: 3.06, 95% CI: 1.21-7.4; p=0.02) and QRS duration (HR: 1.02, 95% CI: 1.01-1.04; p=0.01). Presence of qR in V 1 reflects RV dilation and diastolic interventricular septum flattening. It is a sign of advanced PAH and predicts the risk of death in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrophysiological mechanisms of sophocarpine as a potential antiarrhythmic agent.

PubMed

Yang, Zhi-fang; Li, Ci-zhen; Wang, Wei; Chen, Ying-min; Zhang, Ying; Liu, Yuan-mou; Wang, Hong-wei

2011-03-01

To examine the electrophysiological effects of sophocarpine on action potentials (AP) and ionic currents of cardiac myocytes and to compare some of these effects with those of amiodarone. Langendorff perfusion set-up was used in isolated guinea pig heart, and responses to sophocarpine were monitored using electrocardiograph. Conventional microelectrode, voltage clamp technique and perforated patch were employed to record fast response AP (fAP), slow response AP (sAP) and ionic currents in guinea pig papillary muscle or rabbit sinus node cells. Tachyarrhythmia produced by isoprenaline (15 μmol/L) could be reversed by sophocarpine (300 μmol/L). Sophocarpine (10 μmol/L) decreased the amplitude by 4.0%, maximal depolarization velocity (V(max)) of the fAP by 24.4%, and Na(+) current (I(Na)) by 18.0%, while it prolonged the effective refractory period (ERP) by 21.1%. The same concentration of sophocarpine could also decrease the amplitude and V(max) of the sAP, by 26.8% and 25.7%, respectively, and attenuated the Ca(2+) current (I(CaL)) and the K(+) tail current substantially. Comparison of sophocarpine with amiodarone demonstrated that both prolonged the duration and the ERP of fAP and sAP, both decreased the amplitude and V(max) of the fAP and sAP, and both slowed the automatic heart rate. Sophocarpine could reverse isoprenaline-induced arrhythmia and inhibit I(Na), I(CaL), and I(Kr) currents. The electrophysiological effects of sophocarpine are similar to those of amiodarone, which might be regarded as a prospective antiarrhythmic agent.

Brugada Syndrome. Clinical, Genetic, Molecular, Cellular and Ionic Aspects

PubMed Central

Antzelevitch, Charles; Patocskai, Bence

2015-01-01

The Brugada syndrome (BrS) is an inherited cardiac arrhythmia syndrome first described as a new clinical entity in 1992. Electrocardiographically characterized by distinct coved type ST segment elevation in the right precordial leads, the syndrome is associated with a high risk for sudden cardiac death in young adults, and less frequently in infants and children. The ECG manifestations of the BrS are often concealed and may be unmasked or aggravated by sodium channel blockers, a febrile state, vagotonic agents, as well as by tricyclic and tetracyclic antidepressants. An implantable cardioverter defibrillator (ICD) is the most widely accepted approach to therapy. Pharmacological therapy is designed to produce an inward shift in the balance of currents active during the early phases of the right ventricular action potential and can be used to abort electrical storms or as an adjunct or alternative to device therapy when use of an ICD is not possible. Isoproterenol, cilostazol and milrinone boost calcium channel current and drugs like quinidine, bepridil and the Chinese herb extract Wenxin Keli inhibit the transient outward current, acting to diminish the action potential (AP) notch and thus to suppress the substrate and trigger for VT/VF. Radiofrequency ablation of the right ventricular outflow tract epicardium of BrS patients has recently been shown to reduce arrhythmia-vulnerability and the ECG-manifestation of the disease, presumably by destroying the cells with more prominent AP notch. This review provides an overview of the clinical, genetic, molecular and cellular aspects of the BrS as well as the approach to therapy. PMID:26671757

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.

Smartphone ECG for evaluation of STEMI: results of the ST LEUIS Pilot Study.

PubMed

Muhlestein, Joseph Boone; Le, Viet; Albert, David; Moreno, Fidela Ll; Anderson, Jeffrey L; Yanowitz, Frank; Vranian, Robert B; Barsness, Gregory W; Bethea, Charles F; Severance, Harry W; Ramo, Barry; Pierce, John; Barbagelata, Alejandro; Muhlestein, Joseph Brent

2015-01-01

12-lead ECG is a critical component of initial evaluation of cardiac ischemia, but has traditionally been limited to large, dedicated equipment in medical care environments. Smartphones provide a potential alternative platform for the extension of ECG to new care settings and to improve timeliness of care. To gain experience with smartphone electrocardiography prior to designing a larger multicenter study evaluating standard 12-lead ECG compared to smartphone ECG. 6 patients for whom the hospital STEMI protocol was activated were evaluated with traditional 12-lead ECG followed immediately by a smartphone ECG using right (VnR) and left (VnL) limb leads for precordial grounding. The AliveCor™ Heart Monitor was utilized for this study. All tracings were taken prior to catheterization or immediately after revascularization while still in the catheterization laboratory. The smartphone ECG had excellent correlation with the gold standard 12-lead ECG in all patients. Four out of six tracings were judged to meet STEMI criteria on both modalities as determined by three experienced cardiologists, and in the remaining two, consensus indicated a non-STEMI ECG diagnosis. No significant difference was noted between VnR and VnL. Smartphone based electrocardiography is a promising, developing technology intended to increase availability and speed of electrocardiographic evaluation. This study confirmed the potential of a smartphone ECG for evaluation of acute ischemia and the feasibility of studying this technology further to define the diagnostic accuracy, limitations and appropriate use of this new technology. Copyright © 2015 Elsevier Inc. All rights reserved.

A pilot study of cardiac troponin I in patients with acute myocardial infarction and unstable angina.

PubMed

Selim, Najlaa A; Hmouda, Houssem T

2002-05-01

To assess the value of cardiac troponin I in the initial management of acute myocardial infarction and unstable angina, as well as the concordance between creatine phosphokinase-cardiac isoenzyme and cardiac troponin I. We reviewed retrospectively the charts of 32 patients with acute myocardial infarction or unstable angina admitted to the Intensive Care Unit from the Emergency Room of King Khalid Military City Hospital, Hafar-Al-Batin, Kingdom of Saudi Arabia from April 1998 to September 2000. The time of admission to the intensive care unit, which corresponds to the beginning of thrombolytic therapy, the time when cardiac enzymes (creatine phosphokinase-cardiac isoenzyme and cardiac troponin I) are available as well as number of cardiac troponin I determinations before obtaining a significant positive result (>2ng/ml) and the delay between admission and the first significant positive result of cardiac troponin I, were evaluated. Sixteen patients had confirmed acute myocardial infarction based on the association of typical chest pain, electrocardiographic findings with ST segment elevation and significant increase of the ratio creatine phosphokinase-cardiac isoenzyme/creatine phosphokinase > 10%. Sixteen patients had unstable angina and out of the 16 patients (81.25%) with acute myocardial infarction, 13 received thrombolytic therapy which was initiated on the basis of typical clinical history and electrocardiographic features, before the availability of cardiac enzymes. Troponin I was available in only 13 cases. The number of tests performed in these patients was 32. The first positive result of cardiac troponin I was available within a mean time of 16.66 20.8 hours from admission. The number of negative tests performed before obtaining a frank positive result was 9 in 12 patients. The number of positive tests after having obtained the first frank positive cardiac troponin I result was 10 in 12 patients. In all cases of cardiac troponin I, results were concordant with creatine phosphokinase-cardiac isoenzyme. In the 16 patients with unstable angina, only 11 patients had cardiac troponin I serum level. A total of 21 tests were performed. In 9 patients 14 cardiac troponin I tests were < 2 ng/ml. This was correlated with normal creatine phosphokinase-cardiac isoenzyme/creatine phosphokinase ratio. In 2 patients, 7 cardiac troponin I tests were positive. Both of them had significant increase of creatine phosphokinase-cardiac isoenzyme/creatine phosphokinase ratio and electrocardiographic features of myocardial ischemia and were referred for urgent coronary angiography. Cardiac troponin I levels are not helpful in the initial management of patients with acute myocardial infarction. Thrombolytic therapy should be therefore instituted before the availability of cardiac troponin I results. However, cardiac troponin I results are concordant with creatine phosphokinase-cardiac isoenzyme in retrospective confirmation of the diagnosis of acute myocardial infarction a few hours after onset. In patients with unstable angina, cardiac troponin I should be used mainly for risk stratification.

Detection of driving fatigue by using noncontact EMG and ECG signals measurement system.

PubMed

Fu, Rongrong; Wang, Hong

2014-05-01

Driver fatigue can be detected by constructing a discriminant mode using some features obtained from physiological signals. There exist two major challenges of this kind of methods. One is how to collect physiological signals from subjects while they are driving without any interruption. The other is to find features of physiological signals that are of corresponding change with the loss of attention caused by driver fatigue. Driving fatigue is detected based on the study of surface electromyography (EMG) and electrocardiograph (ECG) during the driving period. The noncontact data acquisition system was used to collect physiological signals from the biceps femoris of each subject to tackle the first challenge. Fast independent component analysis (FastICA) and digital filter were utilized to process the original signals. Based on the statistical analysis results given by Kolmogorov-Smirnov Z test, the peak factor of EMG (p < 0.001) and the maximum of the cross-relation curve of EMG and ECG (p < 0.001) were selected as the combined characteristic to detect fatigue of drivers. The discriminant criterion of fatigue was obtained from the training samples by using Mahalanobis distance, and then the average classification accuracy was given by 10-fold cross-validation. The results showed that the method proposed in this paper can give well performance in distinguishing the normal state and fatigue state. The noncontact, onboard vehicle drivers' fatigue detection system was developed to reduce fatigue-related risks.

Electrocardiographic parameters predict super-response in cardiac resynchronization therapy.

PubMed

Cvijić, Marta; Žižek, David; Antolič, Bor; Zupan, Igor

2015-01-01

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients. However, determinants of response to CRT remain elusive. The aim of the study was to assess the value of ECG parameters to predict super-response in CRT patients. A 12-lead surface ECG was recorded at baseline and immediately after CRT-device implantation. Baseline ECG parameters (QRS duration, bundle branch morphology, axis, PR interval, QTc, intrinsicoid deflection) and post-implant paced QRS duration were analyzed; relative change in QRS duration was calculated. Decrease of left ventricular end-systolic volume ≥30% after 12 months was classified as super-response. In group of 101 patients, 32 (31.7%) were super-responders. There were no significant differences in baseline ECG parameters between super-responders and other patients. Post-implant QRS duration was shorter in super-responders (148 ± 22 ms vs. 162 ± 28 ms; P=0.010). Only in super-responders was significant QRS reduction observed after implantation. Relative QRS shortening was higher in super-responders (12.1% (6.8 to 22.2) vs. 1.7% (-11.9 to 11.8); P=0.005). In a multivariable analysis post-implant QRS duration and relative QRS shortening remained independent predictor of super-response. Absolute post-implant QRS duration and relative QRS shortening are the only ECG parameters associated with super-response in CRT. Further prospective studies on larger population are warranted to determine our findings. Copyright © 2015 Elsevier Inc. All rights reserved.

Illicit narcotic injection masquerading as acute pulmonary embolism.

PubMed

Klochan, Shelley A; Taleb, Mohammed; Hoover, Matthew J; Mauro, Vincent F; Anandan, Vasuki; Willey, James; Cooper, Christopher J

2013-04-01

A 23-year-old male presented from a nursing home with hypotension, tachycardia, diaphoresis and electrocardiographic evidence of right ventricular strain that was confirmed by echocardiography. His differential diagnosis included sepsis and pulmonary embolism. A high-resolution computed tomography scan demonstrated no pulmonary emboli but did demonstrate multiple bilateral pulmonary nodules. Upon questioning he admitted to injecting a long-acting narcotic that had been manually macerated, dissolved in saline, and injected through an indwelling intravenous line. Lung biopsy findings were consistent with cellulose-induced perivascular granulomatosis. Cellulose granulomatosis can be seen in patients who inject medications designed for oral use and should be considered in patients who present with acute pulmonary hypertension.

[The effect of hypothyroidism on cardiac function in dogs].

PubMed

Stephan, I; Nolte, I; Hoppen, H O

2003-06-01

The thyroid hormones have direct and indirect effects on the heart. So it is possible that depression of left ventricular function is associated with hypothyroidism. This publication describes cardiac findings (auscultation, electrocardiography, echocardiography) in ten hypothyroid dogs. Low heart rates, reduced R-amplitudes and bradycardic arrhythmias (first and second-degree AV block) were found on the electrocardiogram before treatment. On the echocardiograms most of the dogs showed reduced contractillity and reduced left ventricular wall thickness. Seven dogs were reexamined after levothyroxine supplementation. Effects of treatment were increased heart rates and R-amplitudes as well as disappearance of the bradycardic arrhythmias in electrocardiographic examination. The echocardiographic examination showed increased contractility and increased left ventricular wall thickness.

ST-segment elevation following lightning strike: case report and review of the literature.

PubMed

Akın, Alper; Bilici, Meki; Demir, Fikri; Gözü Pirinççioğlu, Ayfer; Yıldırım, Ahmet

2015-01-01

Lightning strikes may cause injury to the heart, ranging from slight electrocardiographic changes to fatal damage. As heart injury is the most important cause of mortality in these patients, cardiac monitoring is crucial. Even though various ECG changes have been reported, published data on pathologic ST-segment changes is scarce. Herein, we present a seven-year old patient with ST-segment elevation following a lightning strike. There is not sufficient data regarding lightning-related myocardial ischemia. However, because of the similar effects of lightning strikes and high-voltage electric shocks, we believe myocardial injury related to lightning may be managed in the same manner as is cardiac involvement associated with electric shock.

[Traumatic tricuspid insufficiency. Apropos of 2 cases].

PubMed

Ventre, F; Bertinchant, J P; Noblet, D; Frapier, J M; Carabasse, D; Nigond, J; Ledermann, B; Cohen, S; Joubert, P; Grolleau-Raoux, R

1995-06-01

The authors report two cases of tricuspid regurgitation by a ruptured anterior papillary muscle secondary to non-penetrating thoracic trauma. In the presence of suggestive clinical and electrocardiographic abnormalities (systolic murmur, right heart failure, right bundle branch block), echocardiography confirmed the tricuspid regurgitation, showed its mechanism and excluded any other intracardiac lesions. Tricuspid annuloplasty was performed in both cases because of the persistence of failure or degradation of the patient's clinical condition. Peroperative echocardiography was used to judge the quality of the surgical repair in both cases. Traumatic tricuspid regurgitation is a rare condition and the diagnosis is often delayed. Echocardiography is the investigation of choice and guides treatment which is essentially valvular repair in symptomatic patients.

A Toolkit for Forward/Inverse Problems in Electrocardiography within the SCIRun Problem Solving Environment

PubMed Central

Burton, Brett M; Tate, Jess D; Erem, Burak; Swenson, Darrell J; Wang, Dafang F; Steffen, Michael; Brooks, Dana H; van Dam, Peter M; Macleod, Rob S

2012-01-01

Computational modeling in electrocardiography often requires the examination of cardiac forward and inverse problems in order to non-invasively analyze physiological events that are otherwise inaccessible or unethical to explore. The study of these models can be performed in the open-source SCIRun problem solving environment developed at the Center for Integrative Biomedical Computing (CIBC). A new toolkit within SCIRun provides researchers with essential frameworks for constructing and manipulating electrocardiographic forward and inverse models in a highly efficient and interactive way. The toolkit contains sample networks, tutorials and documentation which direct users through SCIRun-specific approaches in the assembly and execution of these specific problems. PMID:22254301

Five-year follow-up two-dimensional speckle tracking echocardiography in a juvenile with a double-chambered left ventricle.

PubMed

Harada, Kenji; Mori, Kazuhiro; Ichimiya, Chiyo; Terada, Naho; Iima, Tsutomu; Harada, Takafumi; Fujisawa, Kazutoshi; Kawata, Atsushi; Okada, Ayumi; Yamamoto, Hirofumi; Fujinaga, Hiroyuki

2017-05-01

Double-chambered left ventricle (DCLV) is a particularly rare congenital entity characterized by the presence of two ventricular cavities separated by an abnormal muscle band. An asymptomatic 15-year-old boy was referred to our hospital because of electrocardiographic (ECG) abnormalities. His initial transthoracic echocardiography (TTE) demonstrated a DCLV with mild left ventricular systolic dysfunction. During a 5-year follow-up period, he remained symptom free with no changes in ECG and conventional TTE findings. However, two-dimensional speckle tracking echocardiography revealed a subtle progressive deterioration of left ventricular systolic function during the 5-year follow-up. © 2017, Wiley Periodicals, Inc.

Pheochromocytoma presenting with Takotsubo syndrome.

PubMed

Marcovitz, Pamela A; Czako, Peter; Rosenblatt, Solomon; Billecke, Scott S

2010-10-01

The clinical presentation of Takotsubo syndrome, or apical ballooning syndrome, resembles an extensive anterolateral myocardial infarction with chest pain symptoms and electrocardiographic ST-elevation or T-wave inversion noted in most patients. However, coronary arteries are invariably found to be normal or to display minimal atherosclerotic disease despite modest elevation of cardiac enzymes. Since most cases of Takotsubo syndrome occur after intense physical and/or emotional stress, catecholamine surge appears to be a common underlying mechanism. We present a case of Takotsubo syndrome, which presented with unusual symptoms and was found to be caused by pheochromocytoma. A sudden rise in blood pressure moments after completion of echocardiographic stress testing aided in uncovering the diagnosis. ©2010, Wiley Periodicals, Inc.

The diagnostic accuracy of exercise electrocardiography - A review

NASA Technical Reports Server (NTRS)

Johnson, R. L.; Bungo, M. W.

1983-01-01

The cardiovascular 'stress test', and particularly the graded treadmill exercist test, has gained wide acceptance as a diagnostic aid in searching for ischemic heart disease and as a prognostic indicator for those with known coronary artery disease. Controversies still exist, however, in its use in mass screening and in interpreting equivocal tests. A review of the use and value of electrocardiographic exercise testing is presented. Topics such as its use in asymptomatic individuals, the adjuvant use of clinical examination, and the examination of ancillary treadmill parameters are presented. No attempt is made to detail the very significant contributions of radionuclide scanning. The positive exercise electrocardiogram in the asymptomatic subject is discussed and guidelines for clinical management are offered.

Analysis Spectrum of ECG Signal and QRS Detection during Running on Treadmill

NASA Astrophysics Data System (ADS)

Agung Suhendra, M.; Ilham R., M.; Simbolon, Artha I.; Faizal A., M.; Munandar, A.

2018-03-01

The heart is an important organ in our metabolism in which it controls circulatory and oxygen. The heart exercise is needed one of them using the treadmill to prevent health. To analysis, it using electrocardiograph (ECG) to investigating and diagnosing anomalies of the heart. In this paper, we would like to analysis ECG signals during running on the treadmill with kinds of speeds. There are two analysis ECG signals i.e. QRS detection and power spectrum density (PSD). The result of PSD showed that subject 3 has highly for all subject and the result of QRS detection using pan Tomkins algorithm that a percentage of failed detection is an approaching to 0 % for all subject.

[Evaluation of the principles of distribution of electrocardiographic R-R intervals for elaboration of methods of automated diagnosis of cardiac rhythm disorders].

PubMed

Tsukerman, B M; Finkel'shteĭn, I E

1987-07-01

A statistical analysis of prolonged ECG records has been carried out in patients with various heart rhythm and conductivity disorders. The distribution of absolute R-R duration values and relationships between adjacent intervals have been examined. A two-step algorithm has been constructed that excludes anomalous and "suspicious" intervals from a sample of consecutively recorded R-R intervals, until only the intervals between contractions of veritably sinus origin remain in the sample. The algorithm has been developed into a programme for microcomputer Electronica NC-80. It operates reliably even in cases of complex combined rhythm and conductivity disorders.

Atrial anatomy and function postcardioversion: insights from transthoracic and transesophageal echocardiography.

PubMed

Manning, W J; Silverman, D I

1996-01-01

Echocardiography provides a valuable tool for the evaluation and assessment of atrial function in patients with atrial fibrilation (AF). Atrial morphology after restoration of sinus rhythm is dynamic, with a decrease in atrial size if sinus rhythm is maintained and atrial growth among those with sustained AF. Restoration of electrocardiographic sinus rhythm is frequently accompanied by relatively depressed atrial mechanical function, with recovery that appears to be related to multiple factors, including the duration of AF before cardioversion and the mode of cardioversion. Such delay appears to confer ongoing risk for thrombus formation and thromboembolism in the days after cardioversion and argues strongly for the need to maintain therapeutic anticoagulation during the pericardioversion and postcardioversion period.

Removal of EMG and ECG artifacts from EEG based on wavelet transform and ICA.

PubMed

Zhou, Weidong; Gotman, Jean

2004-01-01

In this study, the methods of wavelet threshold de-noising and independent component analysis (ICA) are introduced. ICA is a novel signal processing technique based on high order statistics, and is used to separate independent components from measurements. The extended ICA algorithm does not need to calculate the higher order statistics, converges fast, and can be used to separate subGaussian and superGaussian sources. A pre-whitening procedure is performed to de-correlate the mixed signals before extracting sources. The experimental results indicate the electromyogram (EMG) and electrocardiograph (ECG) artifacts in electroencephalograph (EEG) can be removed by a combination of wavelet threshold de-noising and ICA.

Instantaneous electrocardiographic changes and transient sinus rhythm restoration in severe hyperkalaemia.

PubMed

Gogas, Bill D; Iliodromitis, Efstathios K; Leftheriotis, Dionyssios I; Flevari, Panagiota G; Rallidis, Loukianos S; Kremastinos, Dimitrios T

2011-04-14

Severe hyperkalaemia is a life threatening electrolyte abnormality that if not treated urgently, might cause electric death. Hyperkalaemia induced electrocardiogram (ECG) alterations vary according to the levels and rate of increase of potassium concentration ([K(+)]) in the extracellular milieu but the paradox is that not all these cases provide ECG changes. We describe the first case in the literature of transient sinus rhythm (SR) recovery despite severe hyperkalaemia in a 57-year-old (yo) male patient with impressive ECG changes considering the heart rhythm and QRS morphology. We also review the literature for the mechanism of ECG alterations induced by hyperkalaemia. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Open source cardiology electronic health record development for DIGICARDIAC implementation

NASA Astrophysics Data System (ADS)

Dugarte, Nelson; Medina, Rubén.; Huiracocha, Lourdes; Rojas, Rubén.

2015-12-01

This article presents the development of a Cardiology Electronic Health Record (CEHR) system. Software consists of a structured algorithm designed under Health Level-7 (HL7) international standards. Novelty of the system is the integration of high resolution ECG (HRECG) signal acquisition and processing tools, patient information management tools and telecardiology tools. Acquisition tools are for management and control of the DIGICARDIAC electrocardiograph functions. Processing tools allow management of HRECG signal analysis searching for indicative patterns of cardiovascular pathologies. Telecardiology tools incorporation allows system communication with other health care centers decreasing access time to the patient information. CEHR system was completely developed using open source software. Preliminary results of process validation showed the system efficiency.

Morphofunctional correlations in the experimental study of myocardiopathies under the stress of forced restraint. Note 2: The influence of adrenal imbalance

NASA Technical Reports Server (NTRS)

Dinu, M.; Dolinescu, S.; Sneer, A.

1980-01-01

Tests were performed with 70 rats to determine the effects of restraint on the functions and structure of the myocardium under varying conditions of adrenal imbalance. Results showed that in rats with adrenal imbalance, fasting and restraint produced the same biochemical alterations as in the controls. The morphologic alteractions, as well as their electric expression, were more varied and evident in the animals with adrenal imbalance. Persistence of the microscopic and electrocardiographic alterations after 72 hours restraint in the animals subjected to unilateral adrenalectomy suggests chronic evolution of the myocardial lesions. This proves the necessity of intact adrenals for a good adaptability to stress.

Anaesthetic management of a case of Wolff-Parkinson-White syndrome

PubMed Central

Kabade, Savitri D; Sheikh, Safiya; Periyadka, Bhavya

2011-01-01

We report a case of fibroid uterus with Wolff–Parkinson–White (WPW) syndrome in a 48-year-old female, posted for elective hysterectomy. Patient gave history of short recurrent episodes of palpitation and electrocardiograph confirmed the diagnosis of WPW syndrome. The anaesthetic management of these patients is challenging as they are known to develop life threatening tachyarrhythmia like paroxysmal supra-ventricular tachycardia (PSVT) and atrial fibrillation (AF). Epidural anaesthesia is preferred compared to general anaesthesia to avoid polypharmacy, noxious stimuli of laryngoscopy and intubation. To deal with perioperative complications like PSVT and AF, anti-arrhythmic drugs like adenosine, beta blockers and defibrillator should be kept ready. Perioperative monitoring is essential as patients can develop complications. PMID:22013256

Assessment of atrial electromechanical delay and P-wave dispersion in patients with type 2 diabetes mellitus.

PubMed

Demir, Kenan; Avci, Ahmet; Kaya, Zeynettin; Marakoglu, Kamile; Ceylan, Esra; Yilmaz, Ahmet; Ersecgin, Ahmet; Armutlukuyu, Mustafa; Altunkeser, Bulent Behlul

2016-04-01

Diabetes mellitus is an independent and strong risk factor for development of atrial fibrillation (AF). Electrophysiologic and electromechanical abnormalities are associated with a higher risk of AF. In this study we aimed to determine the correlation of atrial conduction abnormalities between the surface electrocardiographic and tissue Doppler echocardiographic measurements in type 2 diabetes mellitus (T2DM) patients. A total of 88 consecutive T2DM patients and 49 age-, gender-, and body mass index-matched healthy volunteers were included in the present study. Baseline characteristics were recorded and 24-hour ambulatory blood pressure monitoring, transthoracic echocardiography, and 12-lead surface electrocardiography were performed for all study participants. Atrial electromechanical delay (EMD) intervals were measured. Maximum P-wave duration and P-wave dispersion (Pd) were significantly higher in patients with T2DM (105.7±10.2ms vs. 102.2±7.5ms, p=0.02; 40.6±7.6ms vs. 33.6±5.9ms, p<0.001, respectively). Interatrial, intraatrial, and intraleft atrial EMD were significantly higher in the T2DM patients when compared with the controls (16.5±7.8ms vs.11.2±4.4ms, p<0.001; 9.0±7.3ms vs. 6.0±3.8ms, p=0.002, and 7.4±5.2ms vs. 5.1±3.2ms, p=0.002 respectively). Correlation analysis showed a positive correlation between interatrial EMD and Pd (r=0.429, p<0.001) and left atrial volume (r=0.428, p<0.001). In this study, there was significant EMD and Pd in patients with T2DM as compared with healthy volunteers. Additionally, interatrial EMD was correlated with Pd and left atrial volume index. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Differentiating Electromechanical From Non-Electrical Substrates of Mechanical Discoordination to Identify Responders to Cardiac Resynchronization Therapy.

PubMed

Lumens, Joost; Tayal, Bhupendar; Walmsley, John; Delgado-Montero, Antonia; Huntjens, Peter R; Schwartzman, David; Althouse, Andrew D; Delhaas, Tammo; Prinzen, Frits W; Gorcsan, John

2015-09-01

Left ventricular (LV) mechanical discoordination, often referred to as dyssynchrony, is often observed in patients with heart failure regardless of QRS duration. We hypothesized that different myocardial substrates for LV mechanical discoordination exist from (1) electromechanical activation delay, (2) regional differences in contractility, or (3) regional scar and that we could differentiate electromechanical substrates responsive to cardiac resynchronization therapy (CRT) from unresponsive non-electrical substrates. First, we used computer simulations to characterize mechanical discoordination patterns arising from electromechanical and non-electrical substrates and accordingly devise the novel systolic stretch index (SSI), as the sum of posterolateral systolic prestretch and septal systolic rebound stretch. Second, 191 patients with heart failure (QRS duration ≥120 ms; LV ejection fraction ≤35%) had baseline SSI quantified by automated echocardiographic radial strain analysis. Patients with SSI≥9.7% had significantly less heart failure hospitalizations or deaths 2 years after CRT (hazard ratio, 0.32; 95% confidence interval, 0.19-0.53; P<0.001) and less deaths, transplants, or LV assist devices (hazard ratio, 0.28; 95% confidence interval, 0.15-0.55; P<0.001). Furthermore, in a subgroup of 113 patients with intermediate electrocardiographic criteria (QRS duration of 120-149 ms or non-left bundle branch block), SSI≥9.7% was independently associated with significantly less heart failure hospitalizations or deaths (hazard ratio, 0.41; 95% confidence interval, 0.23-0.79; P=0.004) and less deaths, transplants, or LV assist devices (hazard ratio, 0.27; 95% confidence interval, 0.12-0.60; P=0.001). Computer simulations differentiated patterns of LV mechanical discoordination caused by electromechanical substrates responsive to CRT from those related to regional hypocontractility or scar unresponsive to CRT. The novel SSI identified patients who benefited more favorably from CRT, including those with intermediate electrocardiographic criteria, where CRT response is less certain by ECG alone. © 2015 American Heart Association, Inc.

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.

Evaluation of Tp-e interval and Tp-e/QT ratio in patients with non-dipper hypertension.

PubMed

Demir, Mehmet; Uyan, Umut

2014-01-01

Non-dipper hypertension is associated with increased cardiovascular morbidity and mortality. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with non-dipper hypertension. This study included 80 hypertensive patients. Hypertensive patients were divided into two groups: 50 dipper patients (29 male, mean age 51.5 ± 8 years) and 30 non-dipper patients (17 male, mean age 50.6 ± 5.4 years). Tp-e interval and Tp-e/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared between groups. No statistically significant difference was found between two groups in terms of basic characteristics. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in non-dipper patients compared to the dippers (39.4 ± 11.5 versus 27.3 ± 7.5 ms and 37.5 ± 9.5 versus 29.2 ± 6.5 ms, p = 0.001 and p = 0.01, respectively). Tp-e interval and Tp-e/QT ratio were also significantly higher in non-dipper patients (97.5 ± 11.2 versus 84.2 ± 8.3 ms and 0.23 ± 0.02 versus 0.17 ± 0.02, all p value <0.001). Our study revealed that QTd, Tp-e interval and Tp-e/QT ratio are prolonged in patients with non-dipper hypertension.

Myocardial Infarction Injury in Patients with Chronic Lung Disease Entering Pulmonary Rehabilitation: Frequency and Association with Heart Rate Parameters.

PubMed

Sima, Carmen A; Lau, Benny C; Taylor, Carolyn M; van Eeden, Stephan F; Reid, W Darlene; Sheel, Andrew W; Kirkham, Ashley R; Camp, Pat G

2018-03-14

Myocardial infarction (MI) remains under-recognized in chronic lung disease (CLD) patients. Rehabilitation health professionals need accessible clinical measurements to identify the presence of prior MI in order to determine appropriate training prescription. To estimate prior MI in CLD patients entering a pulmonary rehabilitation program, as well as its association with heart rate parameters such as resting heart rate and chronotropic response index. Retrospective cohort design. Pulmonary rehabilitation outpatient clinic in a tertiary care university-affiliated hospital. Eighty-five CLD patients were studied. Electrocardiograms at rest and peak cardiopulmonary exercise testing, performed before pulmonary rehabilitation, were analyzed. Electrocardiographic evidence of prior MI, quantified by the Cardiac Infarction Injury Score (CIIS), was contrasted with reported myocardial events and then correlated with resting heart rate and chronotropic response index parameters. CIIS, resting heart rate, and chronotropic response index. Sixteen CLD patients (19%) demonstrated electrocardiographic evidence of prior MI, but less than half (8%) had a reported MI history (P < .05). The Cohen's kappa test revealed poor level of agreement between CIIS and medical records (kappa = 0.165), indicating that prior MI diagnosis was under-reported in the medical records. Simple and multiple regression analyses showed that resting heart rate but not chronotropic response index was positively associated with CIIS in our population (R 2 = 0.29, P < .001). CLD patients with a resting heart rate higher than 80 beats/min had approximately 5 times higher odds of having prior MI, as evidenced by a CIIS ≥20. CLD patients entering pulmonary rehabilitation are at risk of unreported prior MI. Elevated resting heart rate seems to be an indicator of prior MI in CLD patients; therefore, careful adjustment of training intensity such as intermittent training is recommended under these circumstances. III. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Daily Energy Expenditure and Its Relation to Health Care Costs in Patients Undergoing Ambulatory Electrocardiographic Monitoring.

PubMed

George, Jason; Abdulla, Rami Khoury; Yeow, Raymond; Aggarwal, Anshul; Boura, Judith; Wegner, James; Franklin, Barry A

2017-02-15

Our increasingly sedentary lifestyle is associated with a heightened risk of obesity, diabetes, heart disease, and cardiovascular mortality. Using the recently developed heart rate index formula in 843 patients (mean ± SD age 62.3 ± 15.7 years) who underwent 24-hour ambulatory electrocardiographic (ECG) monitoring, we estimated average and peak daily energy expenditure, expressed as metabolic equivalents (METs), and related these data to subsequent hospital encounters and health care costs. In this cohort, estimated daily average and peak METs were 1.7 ± 0.7 and 5.5 ± 2.1, respectively. Patients who achieved daily bouts of peak energy expenditure ≥5 METs had fewer hospital encounters (p = 0.006) and median health care costs that were nearly 50% lower (p <0.001) than their counterparts who attained <5 METs. In patients whose body mass index was ≥30 kg/m 2 , there were significant differences in health care costs depending on whether they achieved <5 or ≥5 METs estimated by ambulatory ECG monitoring (p = 0.005). Interestingly, patients who achieved ≥5 METs had lower and no significant difference in their health care costs, regardless of their body mass index (p = 0.46). Patients with previous percutaneous coronary intervention who achieved ≥5 METs had lower health care costs (p = 0.044) and fewer hospital encounters (p = 0.004) than those who achieved <5 METs. In conclusion, average and peak daily energy expenditures estimated from ambulatory ECG monitoring may provide useful information regarding health care utilization in patients with and without previous percutaneous coronary intervention, irrespective of body habitus. Our findings are the first to link lower intensities of peak daily energy expenditure, estimated from ambulatory ECG monitoring, with increased health care utilization. Copyright © 2016 Elsevier Inc. All rights reserved.

Alterations in echocardiographic and electrocardiographic features in Japanese professional soccer players: comparison to African-Caucasian ethnicities.

PubMed

Kervio, Gaëlle; Pelliccia, Antonio; Nagashima, Junzo; Wilson, Mathew G; Gauthier, Jean; Murayama, Masahiro; Uzan, Laurent; Ville, Nathalie; Carré, François

2013-10-01

Scarce data are available regarding the electrocardiographic (ECG) and echocardiographic changes in athletes of Asian origin. We investigate the ECG and echocardiographic patterns in Japanese (J) compared with African-Caribbean (AC) and Caucasian (C) athletes. A total of 282 professional soccer players (68 J, 96 AC and 118 C) matched for age, gender, sport and level of achievement was examined. ECGs were without alterations in 62% of J (versus 69% of C, p = non significant and 44% of AC, p < 0.001). The most common alterations in J were sinus bradycardia (69%), incomplete right bundle branch block (RBBB; 43%), early repolarization (18%), isolated increase in R/S-wave (10%), Q-waves (9%). Remarkably, no J athlete showed deeply T-wave inversion, in contrast to 6% of AC (p < 0.05). Occasionally, J showed J-point upward/domed ST-elevation with inverted/biphasic T-wave (6% versus 16.5% in AC, p < 0.01). J demonstrated larger left ventricular (LV) cavity compared with AC and C players (55.2 ± 3.3 versus 52.2 ± 3.8 and 53.9 ± 3.7 mm, respectively, p < 0.01), with an important subset ( > 4%) presenting a markedly enlarged cavity (>60 mm), in the presence of normal systolic/diastolic function and no segmental abnormalities. Therefore, J showed a more eccentric remodelling compared with AC and C (relative wall thickness: 0.31 ± 0.05, 0.38 ± 0.06 and 0.36 ± 0.06, respectively, p < 0.01). J players show the most eccentric LV remodelling compared with C and AC players. In association, certain training-related ECG patterns, i.e. sinus bradycardia and isolated increase in R/S-wave voltage, are present in a larger proportion of J players than previously described in C players. Conversely, no J athlete showed deeply T-wave inversion, as commonly found in AC and occasionally in C.

Comparison of electrocardiographic findings and associated risk factors between Taiwan Chinese and US White adults.

PubMed

Wu, Chih-Cheng; Yeh, Wen-Ting; Crow, Richard S; Bai, Chyi-Huey; Pan, Wen-Harn

2008-08-18

Electrocardiographic (ECG) findings are known to differ by race, however, systematic comparisons of findings between eastern and western countries are rare. To compare the ECG findings and associated coronary heart disease (CHD) risk factors between Taiwan Chinese and US White adults aged >or=40 years. We compared the prevalence rate of Minnesota Code criteria based ECG findings and associated CHD risk factors by using data from the third National Health and Nutrition Examination Survey (NHANES III) and the Nutrition and Health Survey in Taiwan (NAHSIT, 1993-1996). Examining all the ECG findings collectively, we observed a higher prevalence of major Minnesota Code findings in Taiwan Chinese women than in US White women (15.0% vs. 10.5%), particularly ST segment depression (5.4% vs. 2.4%) and T wave abnormalities (10.8% vs. 4.8%). The prevalence of major Minnesota Code findings was similar in both Taiwan Chinese and US White men (22.7% vs. 19.6%). Taiwan Chinese men had a higher prevalence of ST segment elevation (13.7% vs. 0.9%). Taiwan Chinese also had a higher prevalence of left ventricular hypertrophy with repolarization change than US Whites in both sexes (2.7% vs. 1.4% for men, 4.3% vs. 1.3% for women). Taiwan Chinese had more favorable CHD risk factor profiles than US Whites, including lipid profile, obesity, central obesity, and smoking status. The prevalence of hypertension was similar between the two groups, however, a lower percentage of Taiwan Chinese received treatment. Taiwan Chinese men had a lower prevalence of diabetes mellitus than US White men, whereas Taiwan Chinese women had a higher prevalence than US White women. These results suggest that substantial differences in ECG findings exist between Taiwan Chinese and US Whites which cannot be entirely explained by CHD risk factors alone.

Non-photic solar associations of heart rate variability and myocardial infarction

NASA Astrophysics Data System (ADS)

Cornélissen, Germaine; Halberg, Franz; Breus, Tamara; Syutkina, Elena V.; Baevsky, Roman; Weydahl, Andi; Watanabe, Yoshihiko; Otsuka, Kuniaki; Siegelova, Jarmila; Fiser, Bohumil; Bakken, Earl E.

2002-03-01

Alignment of serial epidemiological, physiological, including electrocardiographic data with variations in galactic cosmic rays, geomagnetic activity, and atmospheric pressure suggests the possibility of links among these physical environmental variations and health risks, such as myocardial infarctions and ischemic strokes, among others. An increase in the incidence of myocardial infarction in association with magnetic storms, reported by several investigators from Russia, Israel, Italy and Mexico, accounts in Minnesota for a 5% (220cases/year) increase in mortality during years of maximal solar activity by comparison with years of minimal solar activity. Magnetic storms are also found to decrease heart rate variability (HRV), indicating a possible mechanism since a reduced HRV is a prognostic factor for coronary artery disease and myocardial infarction. Longitudinal electrocardiographic monitoring for a week or much longer spans in different geographic locations, notably in the auroral oval, further suggests that the decrease in HRV affects spectral regions other than that around 3.6s (0.15-0.40Hz), reportedly associated with the parasympathetic nervous system. Differences in some associations are observed from solar cycle to solar cycle, and as a function of solar cycle stage, a finding resolving controversies. Coordinated physiological and physical monitoring, the scope of an international project on the Biosphere and the Cosmos, seeks reference values for a better understanding of environmental effects on human health and for testing the merit of space weather reports that could prompt countermeasures in space and on earth. Physiological data being collected systematically worldwide and morbidity/mortality statistics from causes such as myocardial infarction and stroke constitute invaluable data bases for assessing changes within the physiological range, for detecting environmental effects and for recognizing endogenous as well as exogenous disease-risk syndromes. Timely and timed intervention may then be instituted to lower risk, in preference to exclusive current focus on treating overt disease. These chronodiagnostics are particularly important for those venturing into regions away from hospitals, such as astronauts in space.

Evaluation of a new 3-dimensional color Doppler flow method to quantify flow across the mitral valve and in the left ventricular outflow tract: an in vitro study.

PubMed

Kimura, Sumito; Streiff, Cole; Zhu, Meihua; Shimada, Eriko; Datta, Saurabh; Ashraf, Muhammad; Sahn, David J

2014-02-01

The aim of this study was to assess the accuracy, feasibility, and reproducibility of determining stroke volume from a novel 3-dimensional (3D) color Doppler flow quantification method for mitral valve (MV) inflow and left ventricular outflow tract (LVOT) outflow at different stroke volumes when compared with the actual flow rate in a pumped porcine cardiac model. Thirteen freshly harvested pig hearts were studied in a water tank. We inserted a latex balloon into each left ventricle from the MV annulus to the LVOT, which were passively pumped at different stroke volumes (30-80 mL) using a calibrated piston pump at increments of 10 mL. Four-dimensional flow volumes were obtained without electrocardiographic gating. The digital imaging data were analyzed offline using prototype software. Two hemispheric flow-sampling planes for color Doppler velocity measurements were placed at the MV annulus and LVOT. The software computed the flow volumes at the MV annulus and LVOT within the user-defined volume and cardiac cycle. This novel 3D Doppler flow quantification method detected incremental increases in MV inflow and LVOT outflow in close agreement with pumped stroke volumes (MV inflow, r = 0.96; LVOT outflow, r = 0.96; P < .01). Bland-Altman analysis demonstrated overestimation of both (MV inflow, 5.42 mL; LVOT outflow, 4.46 mL) with 95% of points within 95% limits of agreement. Interobserver variability values showed good agreement for all stroke volumes at both the MV annulus and LVOT. This study has shown that the 3D color Doppler flow quantification method we used is able to compute stroke volumes accurately at the MV annulus and LVOT in the same cardiac cycle without electrocardiographic gating. This method may be valuable for assessment of cardiac output in clinical studies.

Electrocardiographic Findings in Patients With Acute Coronary Syndrome Presenting With Out-of-Hospital Cardiac Arrest.

PubMed

Sarak, Bradley; Goodman, Shaun G; Brieger, David; Gale, Chris P; Tan, Nigel S; Budaj, Andrzej; Wong, Graham C; Huynh, Thao; Tan, Mary K; Udell, Jacob A; Bagai, Akshay; Fox, Keith A A; Yan, Andrew T

2018-02-01

We sought to characterize presenting electrocardiographic findings in patients with acute coronary syndromes (ACSs) and out-of-hospital cardiac arrest (OHCA). In the Global Registry of Acute Coronary Events and Canadian ACS Registry I, we examined presenting and 24- to 48-hour follow-up ECGs (electrocardiogram) of ACS patients who survived to hospital admission, stratified by presentation with OHCA. We assessed the prevalence of ST-segment deviation and bundle branch blocks (assessed by an independent ECG core laboratory) and their association with in-hospital and 6-month mortality among those with OHCA. Of the 12,040 ACS patients, 215 (1.8%) survived to hospital admission after OHCA. Those with OHCA had higher presenting rates of ST-segment elevation, ST-segment depression, T-wave inversion, precordial Q-waves, left bundle branch block (LBBB), and right bundle branch block (RBBB) than those without. Among patients with OHCA, those with ST-segment elevation had significantly lower in-hospital mortality (20.9% vs 33.0%, p = 0.044) and a trend toward lower 6-month mortality (27% vs 39%, p = 0.060) compared with those without ST-segment elevation. Conversely, among OCHA patients, LBBB was associated with significantly higher in-hospital and 6-month mortality rates (58% vs 22%, p <0.001, and 65% vs 28%, p <0.001, respectively). ST-segment depression and RBBB were not associated with either outcome. Sixty-three percent of bundle branch blocks (RBBB or LBBB) on the presenting ECG resolved by 24 to 48 hours. In conclusion, compared with ACS patients without cardiac arrest, those with OHCA had higher rates of ST-segment elevation, LBBB, and RBBB on admission. Among OHCA patients, ST-segment elevation was associated with lower in-hospital mortality, whereas LBBB was associated with higher in-hospital and 6-month mortality. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrocardiographic abnormalities in opiate addicts.

PubMed

Wallner, Christina; Stöllberger, Claudia; Hlavin, Anton; Finsterer, Josef; Hager, Isabella; Hermann, Peter

2008-12-01

To determine in a cross-sectional study the prevalence of electrocardiographic (ECG) abnormalities in opiate addicts who were therapy-seeking and its association with demographic, clinical and drug-specific parameters. In consecutive therapy-seeking opiate addicts, a 12-lead ECG was registered within 24 hours after admission and evaluated according to a pre-set protocol between October 2004 and August 2006. Additionally, demographic, clinical and drug-specific parameters were recorded. Included were 511 opiate-addicts, 25% female, with a mean age of 29 years (range 17-59 years). One or more ECG abnormalities were found in 314 patients (61%). In the 511 patients we found most commonly ST abnormalities (19%), QTc prolongation (13%), tall R- and/or S-waves (11%) and missing R progression (10%). ECG abnormalities were more common in males than in females (64 versus 54%, P < 0.05), and in patients with positive than negative urine findings for cannabis (68 versus 57%, P < 0.05). Patients with ST abnormalities were more often males than females (21 versus 11%, P < 0.05), had a history of seizures less often (16 versus 27%, P < 0.05), had positive than negative urine findings for cannabis more often (26 versus 15%, P < 0.01) and had negative than positive urine findings for methadone more often (21 versus 11%, P < 0.05). QTc prolongation was more frequent in patients with high dosages of maintenance drugs than in patients with medium or low dosages (27 versus 12 versus 10%, P < 0.05) and in patients whose urine findings were positive than negative for methadone (23 versus 11%, P < 0.001) as well as for benzodiazepines (17 versus 9%, P < 0.05). Limitations of the data are that in most cases other risk factors for the cardiac abnormalities were not known. ECG abnormalities are frequent in opiate addicts. The most frequent ECG abnormalities are ST abnormalities, QTc prolongation and tall R- and/or S-waves. ST abnormalities are associated with cannabis, and QTc prolongation with methadone and benzodiazepines.

Clinical variables affecting survival in patients with decompensated diastolic versus systolic heart failure.

PubMed

Gorelik, Oleg; Almoznino-Sarafian, Dorit; Shteinshnaider, Miriam; Alon, Irena; Tzur, Irma; Sokolsky, Ilya; Efrati, Shai; Babakin, Zoanna; Modai, David; Cohen, Natan

2009-04-01

The impact of various clinical variables on long-term survival of patients with acutely decompensated diastolic heart failure (DHF) compared to systolic heart failure (SHF) has not been sufficiently investigated. Clinical, laboratory, electrocardiographic and echocardiographic data were collected and analyzed for all-cause mortality in 473 furosemide-treated patients aged >or=60 years, hospitalized for acutely decompensated HF. Diastolic heart failure patients (n = 183) were more likely to be older, female, hypertensive, obese, with shorter preexisting HF duration, atrial fibrillation, lower New York Heart Association (NYHA) class, lower maintenance furosemide dosages, and to receive calcium antagonists. The SHF group (290 patients) demonstrated prevailing coronary artery disease, nitrate or digoxin treatment, and electrocardiographic conduction disturbances (P

Risk stratification using stress echocardiography: incremental prognostic value over historic, clinical, and stress electrocardiographic variables across a wide spectrum of bayesian pretest probabilities for coronary artery disease.

PubMed

Bangalore, Sripal; Gopinath, Devi; Yao, Siu-Sun; Chaudhry, Farooq A

2007-03-01

We sought to evaluate the risk stratification ability and incremental prognostic value of stress echocardiography over historic, clinical, and stress electrocardiographic (ECG) variables, over a wide spectrum of bayesian pretest probabilities of coronary artery disease (CAD). Stress echocardiography is an established technique for the diagnosis of CAD. However, data on incremental prognostic value of stress echocardiography over historic, clinical, and stress ECG variables in patients with known or suggested CAD is limited. We evaluated 3259 patients (60 +/- 13 years, 48% men) undergoing stress echocardiography. Patients were grouped into low (<15%), intermediate (15-85%), and high (>85%) pretest CAD likelihood subgroups using standard software. The historical, clinical, stress ECG, and stress echocardiographic variables were recorded for the entire cohort. Follow-up (2.7 +/- 1.1 years) for confirmed myocardial infarction (n = 66) and cardiac death (n = 105) was obtained. For the entire cohort, an ischemic stress echocardiography study confers a 5.0 times higher cardiac event rate than the normal stress echocardiography group (4.0% vs 0.8%/y, P < .0001). Furthermore, Cox proportional hazard regression model showed incremental prognostic value of stress echocardiography variables over historic, clinical, and stress ECG variables across all pretest probability subgroups (global chi2 increased from 5.1 to 8.5 to 20.1 in the low pretest group, P = .44 and P = .01; from 20.9 to 28.2 to 116 in the intermediate pretest group, P = .47 and P < .0001; and from 17.5 to 36.6 to 61.4 in the high pretest group, P < .0001 for both groups). A normal stress echocardiography portends a benign prognosis (<1% event rate/y) in all pretest probability subgroups and even in patients with high pretest probability and yields incremental prognostic value over historic, clinical, and stress ECG variables across all pretest probability subgroups. The best incremental value is, however, in the intermediate pretest probability subgroup.

Nonspecific ST-T changes associated with unsatisfactory blood pressure control among adults with hypertension in China: Evidence from the CSPTT study.

PubMed

Bao, Huihui; Cai, Huaxiu; Zhao, Yan; Huang, Xiao; Fan, Fangfang; Zhang, Chunyan; Li, Juxiang; Chen, Jing; Hong, Kui; Li, Ping; Wu, Yanqing; Wu, Qinhua; Wang, Binyan; Xu, Xiping; Li, Yigang; Huo, Yong; Cheng, Xiaoshu

2017-03-01

Nonspecific ST-segment and T-wave (ST-T) changes represent one of the most prevalent electrocardiographic abnormalities in hypertensive patients. However, a limited number of studies have investigated the association between nonspecific ST-T changes and unsatisfactory blood pressure (BP) control in adults with hypertension.The study population comprised 15,038 hypertensive patients, who were selected from 20,702 participants in the China Stroke Primary Prevention Trial. The subjects were examined with electrocardiogram test at the initial visit in order to monitor baseline heart activity. According to the results of the electrocardiogram (defined by Minnesota coding), the subjects were divided into 2 groups: ST-T abnormal and ST-T normal. Unsatisfactory BP control was defined as systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg following antihypertensive treatment during the 4.5-year follow-up period. Multivariate analysis was used to analyze the association between nonspecific ST-T abnormalities and unsatisfactory BP control.Nonspecific ST-T changes were common in hypertensive adults (approximately 8.5% in the study), and more prevalent in women (10.3%) and diabetic patients (13.9%). The unsatisfactory BP control rate was high in the total population (47.0%), notably in the ST-T abnormal group (55.5%). The nonspecific ST-T abnormal group exhibited a significantly greater rate of unsatisfactory BP control (odds ratio [OR] 1.20, 95% confidence interval [CI] [1.06, 1.36], P = 0.005]), independent of traditional risk factors, as demonstrated by multivariate regression analysis. Notable differences were further observed in male subjects (OR 1.51, 95% CI [1.17, 1.94], P = 0.002) and in patients with comorbid diabetes (OR 1.47, 95% CI [1.04, 2.07], P = 0.029).Greater rates of unsatisfactory BP control in hypertensive patients with electrocardiographic nonspecific ST-T abnormalities were observed, notably in the subcategories of the male subjects and the diabetic patients.

The differential diagnosis of acute pericarditis from the normal variant: new electrocardiographic criteria

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

Ginzton, L.E.; Laks, M.M.

1982-05-01

We examined the quantitative electrocardiographic differentiation of acute pericarditis from normal variant ST/T changes. The ECGs of 19 patients with acute pericarditis were compared with those of 20 subjects with typical normal variant changes. Patients were excluded if their ECGs demonstrated conditions that markedly altered repolarization. The positive predictive values (PPV) and negative predictive values (NPV) of previously reported criteria were not high (PPV = 0.54 - 0.83, NPV = 0.56 - 0.58). In contrast, in the present study, a T-wave amplitude in lead V/sub 6/ of less than or equal to 0.3 mV diagnosed acute pericarditis (p < 0.005,more » PPV = 0.85, NPV = 0.85), but there was overlap of patients between the groups. The ratio of the amplitude of the onset of the ST segment of the amplitude of the T wave in that lead (ST/T ratio in V/sub 6/) proved to be the most reliable discriminator. An ST/T ratio greater than or equal to 0.25 diagnosed all patients with acute pericarditis (p less than or equal to 0.005, PPV = 1.0, NPV = 1.0). The ST/T ratio greater than or equal to 0.25 in V/sub 4/, V/sub 5/ (both p < 0.005, PPV = 0.87, NPV = 1.0) and I (p less than or equal to 0.005, PPV = 0.80, NPV = 0.81) were also significant discriminators. Thus, if V/sub 6/ is unavailable, an ST/T ratio greater than or equal to 0.25 in V/sub 5/, V/sub 4/ or I is highly suggestive of acute pericarditis. An ST/T ratio greater than or equal to 0.25 in V/sub 6/ discriminated the ECGs of all patients with acute pericarditis from normal variants in this study.« less

Ventricular Effective Refraction Period and Ventricular Repolarization Analysis in Experimental Tachycardiomyopathy in Swine.

PubMed

Noszczyk-Nowak, Agnieszka; Pasławska, Urszula; Gajek, Jacek; Janiszewski, Adrian; Pasławski, Robert; Zyśko, Dorota; Nicpoń, Józef

2016-01-01

Swine are recognized animal models of human cardiovascular diseases. However, little is known on the CHF-associated changes in the electrophysiological ventricular parameters of humans and animals. The aim of this study was to analyze changes in the durations of ventricular effective refraction period (VERP), QT and QTc intervals of pigs with chronic tachycardia-induced tachycardiomyopathy (TIC). The study was comprised of 28 adult pigs (8 females and 20 males) of the Polish Large White breed. A one-chamber pacemaker was implanted in each of the 28 pigs. Electrocardiographic, echocardiographic and electrophysiological studies were carried out prior to the pacemaker implantation and at subsequent 4-week intervals. All electrocardiographic, echocardiographic and short electrophysiological study measurements in all swine were done under general anesthesia (propofol) after premedication with midazolam, medetomidine, and ketamine. No significant changes in the duration of QT interval and corrected QT interval (QTc) were observed during consecutive weeks of the experiment. The duration of the QTc interval of female pigs was shown to be significantly longer than that of the males throughout the whole study period. Beginning from the 12th week of rapid ventricular pacing, a significant increase in duration of VERP was observed in both male and female pigs. Males and females did not differ significantly in terms of VERP duration determined throughout the whole study period. Ventricular pacing, stimulation with 2 and 3 premature impulses at progressively shorter coupling intervals and an imposed rhythm of 130 bpm or 150 bpm induced transient ventricular tachycardia in one female pig and four male pigs. One episode of permanent ventricular tachycardia was observed. The number of induced arrhythmias increased proportionally to the severity of heart failure and duration of the experiment. However, relatively aggressive protocols of stimulation were required in order to induce arrhythmia in the studied pigs.

Office and Home Blood Pressures as Determinants of Electrocardiographic Left Ventricular Hypertrophy Among Black Nigerians Compared With White Flemish.

PubMed

Odili, Augustine N; Thijs, Lutgarde; Yang, Wen-Yi; Ogedengbe, John O; Nwegbu, Maxwell M; Jacobs, Lotte; Wei, Fang-Fei; Feng, Ying-Mei; Zhang, Zhen-Yu; Kuznetsova, Tatiana; Nawrot, Tim S; Staessen, Jan A

2017-11-01

The association of electrocardiographic left ventricular hypertrophy (ECG-LVH) with blood pressure (BP) in Blacks living in sub-Saharan Africa remains poorly documented. In 225 Black Nigerians and 729 White Flemish, we analyzed QRS voltages and voltage-duration products and 12 criteria diagnostic of ECG-LVH in relation to office BP (mean of 5 consecutive readings) and home BP (duplicate morning and evening readings averaged over 1 week). In multivariable analyses, QRS voltage and voltage-duration indexes were generally higher in Blacks than Whites. By using any of 12 criteria, ECG-LVH was more prevalent among Black than White men (54.4% vs. 36.0%) with no ethnic difference among women (17.1%). Precordial voltages and voltage-duration products increased with office and home systolic BP (SBP), and increases were up to 3-fold steeper in Blacks. In Blacks vs. Whites, increases in the Sokolow-Lyon voltage associated with a 10-mm Hg higher SBP were 0.18 mV (95% confidence interval [CI], 0.09-0.26) vs. 0.06 mV (0.02-0.09) and 0.17 mV (0.07-0.28) vs. 0.11 mV (CI, 0.07-0.15) for office and home BP, respectively, with a significant ethnic gradient (P < 0.05). The risk of ECG-LVH increased more with office and home BP in Blacks than Whites. Associations of ECG voltages and voltage-duration products and risk of ECG-LVH with BP are steeper in Black Nigerians compared with a White reference population. In resource-poor settings of sub-Saharan Africa, the ECG in combination with office and home BP is an essential instrument in risk stratification across the entire BP range. © The Author 2017. Published by Oxford University Press on behalf of the American Journal of Hypertension, Ltd.

New System for Digital to Analog Transformation and Reconstruction of 12-Lead ECGs

PubMed Central

Kothadia, Roshni; Kulecz, Walter B.; Kofman, Igor S.; Black, Adam J.; Grier, James W.; Schlegel, Todd T.

2013-01-01

Introduction We describe initial validation of a new system for digital to analog conversion (DAC) and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer's 12-lead ECG hardware/software into that of any other. Materials and Methods To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long) in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data. Results The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer's analog to digital converter (ADC) as the original digitization, and 28.4 µV per channel when it involved a different manufacturer's ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout. Conclusion Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud-based servers. PMID:23613787

Clinical, Echocardiographic, and Electrocardiographic Predictors of Persistent Atrial Fibrillation after Dual-Chamber Pacemaker Implantation: An Integrated Scoring Model Approach.

PubMed

Cho, Min Soo; Kim, Jun; Kim, Ju Hyeon; Kim, Minsu; Lee, Ji Hyun; Hwang, You Mi; Jo, Uk; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

2016-01-01

Persistent atrial fibrillation (PeAF) predictors after dual-chamber pacemaker (PM) implantation remain unclear. We sought to determine these predictors and establish an integrated scoring model. Data were retrospectively reviewed for 649 patients (63.8 ± 12.3 years, 48.6% male, mean CHA2DS2-VASC score 2.7 ± 2.0) undergoing dual-chamber PM implantation. PeAF was defined as documented AF on two consecutive electrocardiograms acquired ≥7 days apart. During a 7.1-year median follow-up (interquartile range 4.5-10.1 years), 67 (10.3%) patients had PeAF. Multivariable analysis showed the following independent predictors of future PeAF: ischemic stroke or transient ischemic accident history (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.03-3.50, p = 0.040), atrial fibrillation/flutter history (HR 1.80, 95% CI 1.01-3.20, p = 0.046), sinus node disease (HR 2.24, 95% CI 1.16-4.35, p = 0.016), left atrial enlargement (>45 mm, HR 2.14, 95% CI 1.26-3.63, p = 0.005), and time in automatic mode switching >1% at first follow-up interrogation (HR 2.58, 95% CI 1.51-4.42, p < 0.001). An integrated scoring model combining these predictors showed good discrimination performance at the seven-year follow-up. (C-statistic 0.716, 95% CI 0.629-0.802, p < 0.001). Significantly greater seven-year PeAF incidences were seen in patients with higher scores (2-5) than in those with lower scores (0-1) (22.8% ± 3.8% vs. 5.3% ± 1.7%, p < 0.001). In conclusion, an integrated scoring model combining clinical, echocardiographic, and electrocardiographic characteristics is useful for predicting future PeAF in patients with a dual-chamber PM.

Clinical, Echocardiographic, and Electrocardiographic Predictors of Persistent Atrial Fibrillation after Dual-Chamber Pacemaker Implantation: An Integrated Scoring Model Approach

PubMed Central

Cho, Min Soo; Kim, Ju Hyeon; Kim, Minsu; Lee, Ji Hyun; Hwang, You Mi; Jo, Uk; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

2016-01-01

Persistent atrial fibrillation (PeAF) predictors after dual-chamber pacemaker (PM) implantation remain unclear. We sought to determine these predictors and establish an integrated scoring model. Data were retrospectively reviewed for 649 patients (63.8 ± 12.3 years, 48.6% male, mean CHA2DS2–VASC score 2.7 ± 2.0) undergoing dual-chamber PM implantation. PeAF was defined as documented AF on two consecutive electrocardiograms acquired ≥7 days apart. During a 7.1-year median follow-up (interquartile range 4.5–10.1 years), 67 (10.3%) patients had PeAF. Multivariable analysis showed the following independent predictors of future PeAF: ischemic stroke or transient ischemic accident history (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.03–3.50, p = 0.040), atrial fibrillation/flutter history (HR 1.80, 95% CI 1.01–3.20, p = 0.046), sinus node disease (HR 2.24, 95% CI 1.16–4.35, p = 0.016), left atrial enlargement (>45 mm, HR 2.14, 95% CI 1.26–3.63, p = 0.005), and time in automatic mode switching >1% at first follow-up interrogation (HR 2.58, 95% CI 1.51–4.42, p < 0.001). An integrated scoring model combining these predictors showed good discrimination performance at the seven-year follow-up. (C-statistic 0.716, 95% CI 0.629–0.802, p < 0.001). Significantly greater seven-year PeAF incidences were seen in patients with higher scores (2–5) than in those with lower scores (0–1) (22.8% ± 3.8% vs. 5.3% ± 1.7%, p < 0.001). In conclusion, an integrated scoring model combining clinical, echocardiographic, and electrocardiographic characteristics is useful for predicting future PeAF in patients with a dual-chamber PM. PMID:27479069

Use of artificial intelligence to identify cardiovascular compromise in a model of hemorrhagic shock.

PubMed

Glass, Todd F; Knapp, Jason; Amburn, Philip; Clay, Bruce A; Kabrisky, Matt; Rogers, Steven K; Garcia, Victor F

2004-02-01

To determine whether a prototype artificial intelligence system can identify volume of hemorrhage in a porcine model of controlled hemorrhagic shock. Prospective in vivo animal model of hemorrhagic shock. Research foundation animal surgical suite; computer laboratories of collaborating industry partner. Nineteen, juvenile, 25- to 35-kg, male and female swine. Anesthetized animals were instrumented for arterial and systemic venous pressure monitoring and blood sampling, and a splenectomy was performed. Following a 1-hr stabilization period, animals were hemorrhaged in aliquots to 10, 20, 30, 35, 40, 45, and 50% of total blood volume with a 10-min recovery between each aliquot. Data were downloaded directly from a commercial monitoring system into a proprietary PC-based software package for analysis. Arterial and venous blood gas values, glucose, and cardiac output were collected at specified intervals. Electrocardiogram, electroencephalogram, mixed venous oxygen saturation, temperature (core and blood), mean arterial pressure, pulmonary artery pressure, central venous pressure, pulse oximetry, and end-tidal CO(2) were continuously monitored and downloaded. Seventeen of 19 animals (89%) died as a direct result of hemorrhage. Stored data streams were analyzed by the prototype artificial intelligence system. For this project, the artificial intelligence system identified and compared three electrocardiographic features (R-R interval, QRS amplitude, and R-S interval) from each of nine unknown samples of the QRS complex. We found that the artificial intelligence system, trained on only three electrocardiographic features, identified hemorrhage volume with an average accuracy of 91% (95% confidence interval, 84-96%). These experiments demonstrate that an artificial intelligence system, based solely on the analysis of QRS amplitude, R-R interval, and R-S interval of an electrocardiogram, is able to accurately identify hemorrhage volume in a porcine model of lethal hemorrhagic shock. We suggest that this technology may represent a noninvasive means of assessing the physiologic state during and immediately following hemorrhage. Point of care application of this technology may improve outcomes with earlier diagnosis and better titration of therapy of shock.

Space Suit Electrocardiographic Electrode Selection: Are commercial electrodes better than the old Apollo technology?

NASA Technical Reports Server (NTRS)

Redmond, M.; Polk, J. D.; Hamilton, D.; Schuette, M.; Guttromson, J.; Guess, T.; Smith, B.

2005-01-01

The NASA Manned Space Program uses an electrocardiograph (ECG) system to monitor astronauts during extravehicular activity (EVA). This ECG system, called the Operational Bioinstrumentation System (OBS), was developed during the Apollo era. Throughout the Shuttle program these electrodes experienced failures during several EVAs performed from the Space Shuttle and International Space Station (ISS) airlocks. An attempt during Shuttle Flight STS-109 to replace the old electrodes with new commercial off-the-shelf (COTS) disposable electrodes proved unsuccessful. One assumption for failure of the STS-109 COTS electrodes was the expansion of trapped gases under the foam electrode pad, causing the electrode to be displaced from the skin. Given that our current electrodes provide insufficient reliability, a number of COTS ECG electrodes were tested at the NASA Altitude Manned Chamber Test Facility. Methods: OBS disposable electrodes were tested on human test subjects in an altitude chamber simulating an Extravehicular Mobility Unit (EMU) operating pressure of 4.3 psia with the following goals: (1) to confirm the root cause of the flight certified, disposable electrode failure during flight STS-109. (2) to identify an adequate COTS replacement electrode and determine if further modifications to the electrodes are required. (3) to evaluate the adhesion of each disposable electrode without preparation of the skin with isopropyl alcohol. Results: There were several electrodes that failed the pressure testing at 4.3psia, including the electrodes used during flight STS-109. Two electrodes functioned well throughout all testing and were selected for further testing in an EMU at altitude. A vent hole placed in all electrodes was also tested as a possible solution to prevent gas expansion from causing electrode failures. Conclusions: Two failure modes were identified: (1) foam-based porous electrodes entrapped air bubbles under the pad (2) poor adhesion caused some electrodes to fail

[On the first studies of electrophysiology].

PubMed

de Micheli, Alfredo

2011-01-01

A historical outline of the evolution of electrophysiology from the eighteenth century is shortly presented. Topics concerning the so called animal electricity starting from the observations on descharges of Torpedo fish until Bolognese Galvani's researches on the frogs are exposed. The points of view of their oppositionists also are examined. These ones, leaded by the physicist Alessandro Volta, professor in the University of Pavia, believed that electricity detected by galvanists was not inherent to animal but was due to the action of the metallic conductors present in the circuit: contact electricity. Only towards the middle of the nineteenth century the physicist Carlo Matteucci attained to demonstrate the existente of the real animal electricity in form of injury current. It was possible to determine that quantitatively thanks to the capillary electrometer built in 1872 by the French physicist Gabriel Lippmann. This instrument was used by the English physiologist Waller in order to obtain the primitive electrocardiographic tracings in humans (1887). At beginnings of the twentieth century, the Dutch professor Willem Einthoven, of the University of Leiden, introduced his string galvanometer which permitted to allow the modern electrocardiography. So it was possible to record the electrical potentials of myocardial cells, first in vitro, later in isolated and perfused heart, son after in dog's heart in situ and finally in human heart. Therefore now it is possible to effectuate endocardial and epicardial mappings, indispensable in order to diagnose and treat the cardiac arrhythmias.

Electrocardiographic interpretation skills of cardiology residents: are they competent?

PubMed

Sibbald, Matthew; Davies, Edward G; Dorian, Paul; Yu, Eric H C

2014-12-01

Achieving competency at electrocardiogram (ECG) interpretation among cardiology subspecialty residents has traditionally focused on interpreting a target number of ECGs during training. However, there is little evidence to support this approach. Further, there are no data documenting the competency of ECG interpretation skills among cardiology residents, who become de facto the gold standard in their practice communities. We tested 29 Cardiology residents from all 3 years in a large training program using a set of 20 ECGs collected from a community cardiology practice over a 1-month period. Residents interpreted half of the ECGs using a standard analytic framework, and half using their own approach. Residents were scored on the number of correct and incorrect diagnoses listed. Overall diagnostic accuracy was 58%. Of 6 potentially life-threatening diagnoses, residents missed 36% (123 of 348) including hyperkalemia (81%), long QT (52%), complete heart block (35%), and ventricular tachycardia (19%). Residents provided additional inappropriate diagnoses on 238 ECGs (41%). Diagnostic accuracy was similar between ECGs interpreted using an analytic framework vs ECGs interpreted without an analytic framework (59% vs 58%; F(1,1333) = 0.26; P = 0.61). Cardiology resident proficiency at ECG interpretation is suboptimal. Despite the use of an analytic framework, there remain significant deficiencies in ECG interpretation among Cardiology residents. A more systematic method of addressing these important learning gaps is urgently needed. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Electronegative LDL-mediated cardiac electrical remodeling in a rat model of chronic kidney disease

PubMed Central

Lee, An-Sheng; Chen, Wei-Yu; Chan, Hua-Chen; Chung, Ching-Hu; Peng, Hsien-Yu; Chang, Chia-Ming; Su, Ming-Jai; Chen, Chu-Huang; Chang, Kuan-Cheng

2017-01-01

The mechanisms underlying chronic kidney disease (CKD)–associated higher risks for life-threatening ventricular tachyarrhythmias remain poorly understood. In rats subjected to unilateral nephrectomy (UNx), we examined cardiac electrophysiological remodeling and relevant mechanisms predisposing to ventricular arrhythmias. Adult male Sprague-Dawley rats underwent UNx (n = 6) or sham (n = 6) operations. Eight weeks later, the UNx group had higher serum blood urea nitrogen and creatinine levels and a longer electrocardiographic QTc interval than did the sham group. Patch-clamp studies revealed epicardial (EPI)-predominant prolongation of the action potential duration (APD) at 50% and 90% repolarization in UNx EPI cardiomyocytes compared to sham EPI cardiomyocytes. A significant reduction of the transient outward potassium current (Ito) in EPI but not in endocardial (ENDO) cardiomyocytes of UNx rats led to a decreased transmural gradient of Ito. The reduction of Ito currents in UNx EPI cardiomyocytes was secondary to downregulation of KChIP2 but not Kv4.2, Kv4.3, and Kv1.4 protein expression. Incubation of plasma electronegative low-density lipoprotein (LDL) from UNx rats with normal EPI and ENDO cardiomyocytes recapitulated the electrophysiological phenotype of UNx rats. In conclusion, CKD disrupts the physiological transmural gradient of Ito via downregulation of KChIP2 proteins in the EPI region, which may promote susceptibility to ventricular tachyarrhythmias. Electronegative LDL may underlie downregulation of KChIP2 in CKD. PMID:28094801

The evolution of ambulatory ECG monitoring.

PubMed

Kennedy, Harold L

2013-01-01

Ambulatory Holter electrocardiographic (ECG) monitoring has undergone continuous technological evolution since its invention and development in the 1950s era. With commercial introduction in 1963, there has been an evolution of Holter recorders from 1 channel to 12 channel recorders with increasingly smaller storage media, and there has evolved Holter analysis systems employing increasingly technologically advanced electronics providing a myriad of data displays. This evolution of smaller physical instruments with increasing technological capacity has characterized the development of electronics over the past 50 years. Currently the technology has been focused upon the conventional continuous 24 to 48 hour ambulatory ECG examination, and conventional extended ambulatory monitoring strategies for infrequent to rare arrhythmic events. However, the emergence of the Internet, Wi-Fi, cellular networks, and broad-band transmission has positioned these modalities at the doorway of the digital world. This has led to an adoption of more cost-effective strategies to these conventional methods of performing the examination. As a result, the emergence of the mobile smartphone coupled with this digital capacity is leading to the recent development of Holter smartphone applications. The potential of point-of-care applications utilizing the Holter smartphone and a vast array of new non-invasive sensors is evident in the not too distant future. The Holter smartphone is anticipated to contribute significantly in the future to the field of global health. © 2013.

The human respiratory gate

NASA Technical Reports Server (NTRS)

Eckberg, Dwain L.

2003-01-01

Respiratory activity phasically alters membrane potentials of preganglionic vagal and sympathetic motoneurones and continuously modulates their responsiveness to stimulatory inputs. The most obvious manifestation of this 'respiratory gating' is respiratory sinus arrhythmia, the rhythmic fluctuations of electrocardiographic R-R intervals observed in healthy resting humans. Phasic autonomic motoneurone firing, reflecting the throughput of the system, depends importantly on the intensity of stimulatory inputs, such that when levels of stimulation are low (as with high arterial pressure and sympathetic activity, or low arterial pressure and vagal activity), respiratory fluctuations of sympathetic or vagal firing are also low. The respiratory gate has a finite capacity, and high levels of stimulation override the ability of respiration to gate autonomic responsiveness. Autonomic throughput also depends importantly on other factors, including especially, the frequency of breathing, the rate at which the gate opens and closes. Respiratory sinus arrhythmia is small at rapid, and large at slow breathing rates. The strong correlation between systolic pressure and R-R intervals at respiratory frequencies reflects the influence of respiration on these two measures, rather than arterial baroreflex physiology. A wide range of evidence suggests that respiratory activity gates the timing of autonomic motoneurone firing, but does not influence its tonic level. I propose that the most enduring significance of respiratory gating is its use as a precisely controlled experimental tool to tease out and better understand otherwise inaccessible human autonomic neurophysiological mechanisms.

Trypanothione reductase inhibitors: Overview of the action of thioridazine in different stages of Chagas disease.

PubMed

Lo Presti, M Silvina; Bazán, P Carolina; Strauss, Mariana; Báez, Alejandra L; Rivarola, H Walter; Paglini-Oliva, Patricia A

2015-05-01

Thioridazine (TDZ) is a phenothiazine that has been shown to be one of the most potent phenothiazines to inhibit trypanothione reductase irreversibly. Trypanothione reductase is an essential enzyme for the survival of Trypanosoma cruzi in the host. Here, we reviewed the use of this drug for the treatment of T. cruzi experimental infection. In our laboratory, we have studied the effect of TDZ for the treatment of mice infected with different strains of T. cruzi and treated in the acute or in the chronic phases of the experimental infection, using two different schedules: TDZ at a dose of 80 mg/kg/day, for 3 days starting 1h after infection (acute phase), or TDZ 80 mg/kg/day for 12 days starting 180 days post infection (d.p.i.) (chronic phase). In our experience, the treatment of infected mice, in the acute or in the chronic phases of the infection, with TDZ led to a large reduction in the mortality rates and in the cardiac histological and electrocardiographical abnormalities, and modified the natural evolution of the experimental infection. These analyses reinforce the importance of treatment in the chronic phase to decrease, retard or stop the evolution to chagasic myocardiopathy. Other evidence leading to the use of this drug as a potential chemotherapeutic agent for Chagas disease treatment is also revised. Copyright © 2015 Elsevier B.V. All rights reserved.

Atrial flutter with 1:1 conduction in undiagnosed Wolff-Parkinson-White syndrome.

PubMed

Nelson, Jessie G; Zhu, Dennis W

2014-05-01

Atrial flutter with 1:1 atrioventricular conduction via an accessory pathway is an uncommon presentation of Wolff-Parkinson-White syndrome not previously reported in the emergency medicine literature. Wolff-Parkinson-White syndrome, a form of ventricular preexcitation sometimes initially seen and diagnosed in the emergency department (ED), can present with varied tachydysrhythmias for which certain treatments are contraindicated. For instance, atrial fibrillation with preexcited conduction needs specific consideration of medication choice to avoid potential degeneration into ventricular fibrillation. We describe an adult female presenting with a very rapid, regular wide complex tachycardia successfully cardioverted in the ED followed by a normal electrocardiogram (ECG). Electrophysiology study confirmed atrial flutter with 1:1 conduction and revealed an accessory pathway consistent with Wolff-Parkinson-White syndrome, despite lack of ECG findings of preexcitation during sinus rhythm. Why should an emergency physician be aware of this? Ventricular tachycardia must be the first consideration in patients with regular wide complex tachycardia. However, clinicians should consider atrial flutter with 1:1 conduction related to an accessory pathway when treating patients with the triad of very rapid rate (>250 beats/min), wide QRS complex, and regular rhythm, especially when considering pharmacologic treatment. Emergency physicians also should be aware of electrocardiographically concealed accessory pathways, and that lack of delta waves does not rule out preexcitation syndromes such as Wolff-Parkinson-White syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

L-Arginine attenuates the ethylene glycol induced urolithiasis in ininephrectomized hypertensive rats: role of KIM-1, NGAL, and NOs.

PubMed

Kandhare, Amit D; Patil, Mithun V K; Bodhankar, Subhash L

2015-05-01

Ethylene glycol (EG) exposure caused formation of calcium oxalate crystal that led to renal failure, which is associated with higher prevalence of hypertension. L-Arginine is known to have an antioxidant and nephro-protective potential. To evaluate the effect of L-arginine against EG-induced urolithiasis in uninephrectomized hypertensive rats. Uninephrectomized male Wistar rats (180-200 g) were used to induce urinary calculi through oral administration of EG (0.75%) in distilled water. Rats were treated with either distilled water (10 mg/kg, p.o.) or telmisartan (10 mg/kg, p.o.) or Cystone (500 mg/kg, p.o.) or L-arginine (250, 500, and 1000 mg/kg, p.o.) for 28 days. Various hemodynamic, biochemical, molecular, and histological parameters were assessed in kidney and heart. Rats treated with L-arginine (500 and 1000 mg/kg) significantly restored altered relative organ weight, urine output, urine density, urinary pH, and water intake. EG-induced alterations in electrocardiographic (QRS interval, HR, and ST height) and hemodynamic (SBP, DBP, MABP, and LVEDP) abnormalities were significantly restored by L-arginine (500 and 1000 mg/kg) treatment. It also significantly restored alteration in serum and urine biochemical parameters induced by EG. The elevated oxido-nitrosative stress was also significantly decreased by L-arginine (500 and 1000 mg/kg) treatment. It also significantly down-regulated EG-induced up-regulated renal KIM-1, NGAL, eNOS, and iNOs mRNA expressions. Histological aberrations induced in the renal and cardiac tissues were also ameliorated by l-arginine treatment. L-Arginine exerts its nephro- and cardio-protective potential in EG-induced urolithiasis in uninephrectomized hypertensive rats via modulation of KIM-1, NGAL, eNOS, and iNOs mRNA expression.

Female False Positive Exercise Stress ECG Testing - Fact Verses Fiction.

PubMed

Fitzgerald, Benjamin T; Scalia, William M; Scalia, Gregory M

2018-03-07

Exercise stress testing is a well validated cardiovascular investigation. Accuracy for treadmill stress electrocardiograph (ECG) testing has been documented at 60%. False positive stress ECGs (exercise ECG changes with non-obstructive disease on anatomical testing) are common, especially in women, limiting the effectiveness of the test. This study investigates the incidence and predictors of false positive stress ECG findings, referenced against stress echocardiography (SE) as a standard. Stress echocardiography was performed using the Bruce treadmill protocol. False positive stress ECG tests were defined as greater than 1mm of ST depression on ECG during exertion, without pain, with a normal SE. Potential causes for false positive tests were recorded before the test. Three thousand consecutive negative stress echocardiograms (1036 females, 34.5%) were analysed (age 59+/-14 years. False positive (F+) stress ECGs were documented in 565/3000 tests (18.8%). F+ stress ECGs were equally prevalent in females (194/1036, 18.7%) and males (371/1964, 18.9%, p=0.85 for the difference). Potential causes (hypertension, left ventricular hypertrophy, known coronary disease, arrhythmia, diabetes mellitus, valvular heart disease) were recorded in 36/194 (18.6%) of the female F+ ECG tests and 249/371 (68.2%) of the male F+ ECG tests (p<0.0001 for the difference). These data suggest that F+ stress ECG tests are frequent and equally common in women and men. However, most F+ stress ECGs in men can be predicted before the test, while most in women cannot. Being female may be a risk factor in itself. These data reinforce the value of stress imaging, particularly in women. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

A Framework for Image-Based Modeling of Acute Myocardial Ischemia Using Intramurally Recorded Extracellular Potentials.

PubMed

Burton, Brett M; Aras, Kedar K; Good, Wilson W; Tate, Jess D; Zenger, Brian; MacLeod, Rob S

2018-05-21

The biophysical basis for electrocardiographic evaluation of myocardial ischemia stems from the notion that ischemic tissues develop, with relative uniformity, along the endocardial aspects of the heart. These injured regions of subendocardial tissue give rise to intramural currents that lead to ST segment deflections within electrocardiogram (ECG) recordings. The concept of subendocardial ischemic regions is often used in clinical practice, providing a simple and intuitive description of ischemic injury; however, such a model grossly oversimplifies the presentation of ischemic disease-inadvertently leading to errors in ECG-based diagnoses. Furthermore, recent experimental studies have brought into question the subendocardial ischemia paradigm suggesting instead a more distributed pattern of tissue injury. These findings come from experiments and so have both the impact and the limitations of measurements from living organisms. Computer models have often been employed to overcome the constraints of experimental approaches and have a robust history in cardiac simulation. To this end, we have developed a computational simulation framework aimed at elucidating the effects of ischemia on measurable cardiac potentials. To validate our framework, we simulated, visualized, and analyzed 226 experimentally derived acute myocardial ischemic events. Simulation outcomes agreed both qualitatively (feature comparison) and quantitatively (correlation, average error, and significance) with experimentally obtained epicardial measurements, particularly under conditions of elevated ischemic stress. Our simulation framework introduces a novel approach to incorporating subject-specific, geometric models and experimental results that are highly resolved in space and time into computational models. We propose this framework as a means to advance the understanding of the underlying mechanisms of ischemic disease while simultaneously putting in place the computational infrastructure necessary to study and improve ischemia models aimed at reducing diagnostic errors in the clinic.

Remodeling of repolarization and arrhythmia susceptibility in a myosin-binding protein C knockout mouse model.

PubMed

Toib, Amir; Zhang, Chen; Borghetti, Giulia; Zhang, Xiaoxiao; Wallner, Markus; Yang, Yijun; Troupes, Constantine D; Kubo, Hajime; Sharp, Thomas E; Feldsott, Eric; Berretta, Remus M; Zalavadia, Neil; Trappanese, Danielle M; Harper, Shavonn; Gross, Polina; Chen, Xiongwen; Mohsin, Sadia; Houser, Steven R

2017-09-01

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiac diseases and among the leading causes of sudden cardiac death (SCD) in the young. The cellular mechanisms leading to SCD in HCM are not well known. Prolongation of the action potential (AP) duration (APD) is a common feature predisposing hypertrophied hearts to SCD. Previous studies have explored the roles of inward Na + and Ca 2+ in the development of HCM, but the role of repolarizing K + currents has not been defined. The objective of this study was to characterize the arrhythmogenic phenotype and cellular electrophysiological properties of mice with HCM, induced by myosin-binding protein C (MyBPC) knockout (KO), and to test the hypothesis that remodeling of repolarizing K + currents causes APD prolongation in MyBPC KO myocytes. We demonstrated that MyBPC KO mice developed severe hypertrophy and cardiac dysfunction compared with wild-type (WT) control mice. Telemetric electrocardiographic recordings of awake mice revealed prolongation of the corrected QT interval in the KO compared with WT control mice, with overt ventricular arrhythmias. Whole cell current- and voltage-clamp experiments comparing KO with WT mice demonstrated ventricular myocyte hypertrophy, AP prolongation, and decreased repolarizing K + currents. Quantitative RT-PCR analysis revealed decreased mRNA levels of several key K + channel subunits. In conclusion, decrease in repolarizing K + currents in MyBPC KO ventricular myocytes contributes to AP and corrected QT interval prolongation and could account for the arrhythmia susceptibility. NEW & NOTEWORTHY Ventricular myocytes isolated from the myosin-binding protein C knockout hypertrophic cardiomyopathy mouse model demonstrate decreased repolarizing K + currents and action potential and QT interval prolongation, linking cellular repolarization abnormalities with arrhythmia susceptibility and the risk for sudden cardiac death in hypertrophic cardiomyopathy. Copyright © 2017 the American Physiological Society.

Prognostic significance of ventricular late potentials in patients with pulmonary sarcoidosis.

PubMed

Yodogawa, Kenji; Seino, Yoshihiko; Ohara, Toshihiko; Iwasaki, Yu-Ki; Hayashi, Meiso; Miyauchi, Yasushi; Azuma, Arata; Shimizu, Wataru

2018-06-01

Early detection of cardiac involvement in sarcoidosis is difficult but essential to achieve optimal treatment. Signal-averaged electrocardiography (SAECG) can detect subtle cardiac electrical abnormalities termed late potentials (LPs) and would be useful for the early diagnosis of cardiac involvement. This study aims to investigate the prognostic significance of LP in patients with pulmonary sarcoidosis. We prospectively studied 74 patients with pulmonary sarcoidosis without overt electrocardiographic abnormalities. All participants underwent SAECG, cardiac echocardiography, and 24-hour ambulatory Holter monitoring. Serum angiotensin-converting enzyme and B-type natriuretic peptide levels were also evaluated. We followed these patients for the evaluation of incidence of cardiac events including cardiac death, arrhythmias, and heart failure requiring hospital admission. Of the studied population, 29 patients (39.2%) had detectable LP. During a mean follow-up period of 9.8 years, 8 patients with LPs had cardiovascular events, including development of complete atrioventricular block (n = 4), ventricular tachycardia (n = 2), and heart failure (n = 2). Meanwhile, only 1 of 45 patients without LP developed cardiac event (heart failure). Multivariate analyses revealed that LPs were associated with an increased risk of developing cardiac events (hazard ratio 9.66; 95% confidence interval 1.20-78.01; P = .033) whereas age, sex, serum angiotensin-converting enzyme and B-type natriuretic peptide levels, number of premature ventricular contractions on 24-hour Holter monitoring, and echocardiographic parameters were not associated with subsequent cardiac events. SAECG might possibly be useful for the early detection of cardiac sarcoidosis and, if independently validated, could eventually be considered as a screening test for further risk stratification. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

[Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features].

PubMed

Di, C Y; Wan, Z; Li, K; Ding, Y S; Lin, W H

2017-12-01

Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group ( n= 4) and the complete left bundle branch block (CLBBB) group ( n= 4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P> 0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, P< 0.05]. Conclusion: Bundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.

Streaming potential generated by a pressure-driven flow over a super-hydrophobic surface

NASA Astrophysics Data System (ADS)

Zhao, Hui

2010-11-01

The streaming potential generated by a pressured-driven flow over a weakly charged striped slip-stick surface (the zeta potential of the surface is smaller than the thermal potential (25 mV) with an arbitrary double layer thickness is theoretically studied by solving the Poisson-Boltzmann equation and Stokes equation. A series solution of the streaming potential is derived. Approximate expressions for the streaming potential in the limits of thin double layers and thick double layers are also presented, in excellent agreement with the full solution. The streaming potential is compared against that over a homogenously charged smooth surface. Our results indicate that the streaming potential over a super-hydrophobic surface only can be enhanced when the liquid-gas interface is charged. In addition, as the double layer thickness increases, the advantage of the super-hydrophobic surface diminishes. The impact of a slip-stick surface on the streaming potential might provide guidance for designing novel and efficient microfludic energy conversion devices using a super-hydrophobic surface.

Toxicity of aerosol propellants in the respiratory and circulatory systems. VI. Influence of cardiac and pulmonary vascular lesions in the rat.

PubMed

Doherty, R E; Aviado, D M

1975-01-01

Three propellants were selected for investigation in rats because of their non-uniform effect in mice and monkeys. Trichlorofluoromethane (FC 11) provoked arrhythmia in all three animal species, dichlorodifluoromethane (FC 12) in monkeys and rats but not in mice, and difluoroethane (FC 152a) only in rats. In rats the alterations in heart rate and electrocardiographic pattern during inhalation of these propellants are largely brought about by release of catecholamines from the adrenal gland, because adrenalectomy or prior injection of beta-adrenergic blocking drugs decreased the incidence of cardiac effects. Rats that have pulmonary vascular thrombosis or cardiac necrosis become more sensitive to proarrhythmic activity of these propellants.

Sudden cardiac death in athletes: a guide for emergency physicians.

PubMed

Germann, Carl A; Perron, Andrew D

2005-07-01

A conditioned athlete is usually regarded as a member of the healthiest segment of society, and exercise itself is looked upon as a means to improve health. Although extremely uncommon, sudden cardiac death (SCD) in young athletes is a devastating medical event to all involved (patient, family, community, team, and caregivers). Most etiologies of SCD in athletes result in the same final common denominator (cardiac arrest) on presentation to an emergency physician. There are, however, certain historic, physical examination, and electrocardiographic features of many of these disease processes that emergency physicians should have a working knowledge of to try to identify them before they result in SCD. This review examines the clinical presentation, diagnostic techniques, and management options applicable to emergency practitioners.

[Challenges to implementation of the ECG reading center in ELSA-Brasil].

PubMed

Ribeiro, Antonio Luiz; Pereira, Samuel Vianney da Cunha; Bergmann, Kaiser; Ladeira, Roberto Marini; Oliveira, Rackel Aguiar Mendes; Lotufo, Paulo A; Mill, José Geraldo; Barreto, Sandhi Maria

2013-06-01

Electrocardiography is an established low-cost method of cardiovascular assessment, utilized for decades large epidemiological studies. Nonetheless, its use in large epidemiological studies presents challenges, especially when seeking to develop a reading center. This article describes the process, difficulties and challenges of implementing an electrocardiogram reading center in Brazilian Longitudinal Study for Adult Health (ELSA-Brasil). Among the issues discussed, we have emphasized: the criteria for selection of the electrocardiography machine and the central for storage and management of the machines; the required personnel; the procedures for acquisition and transmission of electrocardiographs to the Reading Center; coding systems, with emphasis on the Minnesota code; ethical and practical issues regarding the delivery of reports to study participants; and aspects related to quality control.