Physiological Effects of Training.
1985-06-25
applies only to short-term programs, the resting heart rate is norrally reduced as a result of aerobic training in all age groups. I0 Studies with ...in order to maintain cardiao output in conjunction with a decreased heart rate, stroke volume has to Increase. Stroke volume increases in the...volume is partially due too increased end diastolic volume. Thus, the pumping ability of the heart , I.e. increased stroke volume, is improved with
Perrichon, Prescilla; Grosell, Martin; Burggren, Warren W.
2017-01-01
Understanding cardiac function in developing larval fishes is crucial for assessing their physiological condition and overall health. Cardiac output measurements in transparent fish larvae and other vertebrates have long been made by analyzing videos of the beating heart, and modeling this structure using a conventional simple prolate spheroid shape model. However, the larval fish heart changes shape during early development and subsequent maturation, but no consideration has been made of the effect of different heart geometries on cardiac output estimation. The present study assessed the validity of three different heart models (the “standard” prolate spheroid model as well as a cylinder and cone tip + cylinder model) applied to digital images of complete cardiac cycles in larval mahi-mahi and red drum. The inherent error of each model was determined to allow for more precise calculation of stroke volume and cardiac output. The conventional prolate spheroid and cone tip + cylinder models yielded significantly different stroke volume values at 56 hpf in red drum and from 56 to 104 hpf in mahi. End-diastolic and stroke volumes modeled by just a simple cylinder shape were 30–50% higher compared to the conventional prolate spheroid. However, when these values of stroke volume multiplied by heart rate to calculate cardiac output, no significant differences between models emerged because of considerable variability in heart rate. Essentially, the conventional prolate spheroid shape model provides the simplest measurement with lowest variability of stroke volume and cardiac output. However, assessment of heart function—especially if stroke volume is the focus of the study—should consider larval heart shape, with different models being applied on a species-by-species and developmental stage-by-stage basis for best estimation of cardiac output. PMID:28725199
Instantaneous stroke volume by PDE during and after constant LBNP (-50 torr)
NASA Technical Reports Server (NTRS)
1980-01-01
Six male subjects were exposed to -50 torr lower body negative pressure (LBNP) for 10 min while stroke volume was recorded beat by beat at regular intervals before, during and after release of LBNP. Stroke volume was calculated from the systolic velocity integral in the ascending aorta by pulsed Doppler echocardiography (PDE) and the cross sectional area of the vessel by M mode echocardiography. Changes in leg volume were recorded continuously and blood pressure was taken every minute. Stroke volume dropped by 51% of the control in the first 33 sec of LBNP and continued to decline slowly to -62% toward the end. Heart rate increased by 15% in the first 10 sec and was 22% above control at the end of exposure. The resulting cardiac output closely followed the course of stroke volume (-47% at 33 sec, -53% at 8 min) showing that the modest increase in heart rate did little to offset the drop in stroke volume. Leg volume increased markedly within the first 10 sec with a more gradual rise reaching +3.5% at the end. Upon sudden release of LBNP, leg volume dropped significantly during the first 3 sec simultaneously with an increase in stroke volume followed by a substantial decline in heart rate below the baseline.
2014-01-09
workloads were determined by matching heart rate responses from each LBNP level. Heart rate and stroke volume (SV) were measured via Finom- eter. ECG, heat...learning algorithm for the assessment of central blood volume via pulse pressure [a noninvasive surrogate of stroke volume (SV)]. These data...30 130 125 120 115 110 105 100 Actual - Finometer Predicted - Algorithm Fig. 3. Comparison of average stroke volume (SV) derived from the
Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review
Vieira, Stella S.; Lemes, Brunno; de T. C. de Carvalho, Paulo; N. de Lima, Rafael; S. Bocalini, Danilo; A. S. Junior, José; Arsa, Gisela; A. Casarin, Cezar; L. Andrade, Erinaldo; J. Serra, Andrey
2016-01-01
Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load. PMID:27347221
Left ventricular function during lower body negative pressure
NASA Technical Reports Server (NTRS)
Ahmad, M.; Blomqvist, C. G.; Mullins, C. B.; Willerson, J. T.
1977-01-01
The response of the human left ventricle to lower body negative pressure (LBNP) and the relation between left ventricular function and hemodynamic response were investigated. Ventricular function curves relating stroke volume to end-diastolic volume were obtained in 12 normal men. Volume data were derived from echocardiographic measurements of left ventricular end-systolic and end-diastolic diameters at rest and during lower body negative pressure (LBNP) at minus 40 mm Hg. End-diastolic volume decreased by 19% and stroke volume by 22%. There were no significant changes in heart rate, arterial blood pressure, or end-systolic volume. Thus, moderate levels of LBNP significantly reduce preload and stroke volume without affecting contractile state. The absence of significant changes in heart rate and arterial blood pressure in the presence of a significant reduction in stroke volume is consistent with an increase in systemic peripheral resistance mediated by low-pressure baroreceptors.
Improved cardiac filling facilitates the postprandial elevation of stroke volume in Python regius.
Enok, Sanne; Leite, Gabriella S P C; Leite, Cléo A C; Gesser, Hans; Hedrick, Michael S; Wang, Tobias
2016-10-01
To accommodate the pronounced metabolic response to digestion, pythons increase heart rate and elevate stroke volume, where the latter has been ascribed to a massive and fast cardiac hypertrophy. However, numerous recent studies show that heart mass rarely increases, even upon ingestion of large meals, and we therefore explored the possibility that a rise in mean circulatory filling pressure (MCFP) serves to elevate venous pressure and cardiac filling during digestion. To this end, we measured blood flows and pressures in anaesthetized Python regius The anaesthetized snakes exhibited the archetypal tachycardia as well as a rise in both venous pressure and MCFP that fully account for the approximate doubling of stroke volume. There was no rise in blood volume and the elevated MCFP must therefore stem from increased vascular tone, possibly by means of increased sympathetic tone on the veins. Furthermore, although both venous pressure and MCFP increased during volume loading, there was no evidence that postprandial hearts were endowed with an additional capacity to elevate stroke volume. In vitro measurements of force development of paced ventricular strips also failed to reveal signs of increased contractility, but the postprandial hearts had higher activities of cytochrome oxidase and pyruvate kinase, which probably serves to sustain the rise in cardiac work during digestion. © 2016. Published by The Company of Biologists Ltd.
Exercise science: research to sustain and enhance performance
NASA Astrophysics Data System (ADS)
Wingo, Jonathan E.
2013-05-01
Cardiovascular adjustments accompanying exercise in high ambient temperatures are likely responsible for diminished aerobic capacity and performance in such conditions. These adjustments include a phenomenon known as cardiovascular drift in which heart rate rises and stroke volume declines progressively over time during constant-rate exercise. A variety of factors modulate the magnitude of cardiovascular drift, e.g., elevated core and skin temperatures, dehydration, and exercise intensity. Regardless of the mode of manipulation, decreases in stroke volume associated with cardiovascular drift result in directionally and proportionally similar decreases in maximal aerobic capacity. Maximal aerobic capacity is determined by maximal heart rate, maximal tissue oxygen extraction, and maximal stroke volume. Because maximal heart rate and maximal tissue oxygen extraction are unaffected during exercise in the heat, decreased stroke volume associated with cardiovascular drift likely persists during maximal efforts and explains the decrease in maximal aerobic capacity. Decreased maximal aerobic capacity results in a greater perceptual and physiological strain accompanying any given level of work. Therefore, sustaining and enhancing performance involves sophisticated monitoring of physiological strain combined with development of countermeasures that mitigate the magnitude of deleterious phenomena like cardiovascular drift.
Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)
NASA Technical Reports Server (NTRS)
Pantalos, George M.; Bennett, Thomas E.; Sharp, M. Keith; Woodruff, Stewart; Oleary, Sean; Gillars, Kevin; Lemon, Mark; Sojka, Jan
1995-01-01
The investigation of cardiovascular adaptation to space flight has seen substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented an initial increase, followed by a progressive reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been identified. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a Get Away Special (GAS) payload within the next year.
Lord, Rachel; MacLeod, David; George, Keith; Oxborough, David; Shave, Rob; Stembridge, Mike
2018-04-01
What is the central question of this study? A reduction in left ventricular (LV) filling, and concomitant increase in heart rate, augments LV mechanics to maintain stroke volume (SV); however, the impact of reduced LV filling in isolation on SV and LV mechanics is currently unknown. What is the main finding and its importance? An isolated decrease in LV filling did not provoke a compensatory increase in mechanics to maintain SV; in contrast, LV mechanics and SV were reduced. These data indicate that when LV filling is reduced without changes in heart rate, LV mechanics do not compensate to maintain SV. An acute non-invasive reduction in preload has been shown to augment cardiac mechanics to maintain stroke volume and cardiac output. Such interventions induce concomitant changes in heart rate, whereas blood volume extraction reduces preload without changes in heart rate. Therefore, the purpose of this study was to determine whether a preload reduction in isolation resulted in augmented stroke volume achieved via enhanced cardiac mechanics. Nine healthy volunteers (four female, age 29 ± 11 years) underwent echocardiography for the assessment of left ventricular (LV) volumes and mechanics in a supine position at baseline and end extraction after the controlled removal of 25% of total blood volume (1062 ± 342 ml). Arterial blood pressure was monitored continuously by a pressure transducer attached to an indwelling radial artery catheter. Heart rate and total peripheral resistance were unchanged from baseline to end extraction, but systolic blood pressure was reduced (from 148 to 127 mmHg). From baseline to end extraction there were significant reductions in left ventricular end-diastolic volume (from 89 to 71 ml) and stroke volume (from 56 to 37 ml); however, there was no change in LV twist, basal or apical rotation. In contrast, LV longitudinal strain (from -20 to -17%) and basal circumferential strain (from -22 to -19%) were significantly reduced from baseline to end extraction. In conclusion, a reduction in preload during blood volume extraction does not result in compensatory changes in stroke volume or cardiac mechanics. Our data suggest that LV strain is dependent on LV filling and consequent geometry, whereas LV twist could be mediated by heart rate. © 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.
Cardiorespiratory responses to orthostasis and the effects of propranolol
NASA Technical Reports Server (NTRS)
Loeppky, J. A.
1975-01-01
Cardiac output and gas exchange were determined serially using the single-breath method of Kim et al. before, during, and after orthostasis on six subjects after beta-adrenergic blockage and in duplicate controls. In the latter, heart rate increased and pulse pressure dropped immediately on tilting to 60 deg and remained stable while cardiac output and stroke volume declined gradually over 21 min upright. On propranolol, heart rate was 10 bpm lower supine and 20 bpm less at 60 deg but cardiac output was only slightly lower before and following tilt-up. However, after 15 min upright, stroke volume and cardiac output recovered on propranolol exceeding the controls after 21 min without change in heart rate. Returning to supine, heart rate dropped in all tests with a transitory increase in stroke volume, cardiac output and arteriovenous O2 difference. At the same time, apparent O2 uptake increased temporarily, reflecting the return of pooled venous blood to the lungs. Orthostatic tolerance did not appear to be affected by beta-adrenergic blockade.
Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias
2016-02-01
Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output. © 2016. Published by The Company of Biologists Ltd.
Changes in cardiac output and tibial artery flow during and after progressive LBNP
NASA Technical Reports Server (NTRS)
1980-01-01
A 3.0 MHz Pulsed Doppler velocity meter (PD) was used to determine blood velocities in the ascending aorta from the suprasternal notch before, during and after progressive 5 min stages of lower body negative pressure (LBNP) in 7 subjects. Changes in stroke volume were calculated from the systolic velocity integrals. A unique 20 MHz PD was used to estimate bloodflow in the posterior tibial artery. With -20 torr mean stroke volume fell 11% and then continued to decline by 48% before LBNP was terminated. Mean tibial flow fell progressively with LBNP stress, due to an increase in reverse flow component and a reduction in peak forward flow and diameter. Stroke volume increased and heart rate fell dramatically during the first 15 sec of recovery. The LBNP was terminated early in 2 subjects because of vasovagal symptons (V). During V the stroke volume rose 86% which more than compensated for the drop in heart rate. This implies that V is accompanied by a paradoxical increase in venous return and that the reduction in HR is the primary cardiovascular event. During the first 15 sec of recovery these 2 subjects had a distinctive marked rise to heart rate reminiscent of the Bainbridge reflex.
Beat by beat stroke volume assessment by PDE in upright and supine exercise
NASA Technical Reports Server (NTRS)
1980-01-01
A 3.0 MHz pulse Doppler echocardiograph was used to estimate instantaneous stroke volume and cardiac output in 8 men during steady state supine and upright exercise at 300 kpm/min which were compared with other studies utilizing invasive procedures. The mean transients in heart rate and stroke volume and cardiac output for the first 20 sec of exercise in each posture were then determined. Centerline blood velocities were obtained in the ascending aorta with the transducer positioned manually in the suprasternal notch. Mean supine values for stroke volume and cardiac output at rest and exercise were 111 (6.4) and 112 ml (9.7 L/min), respectively, for supine. The corresponding results for upright were 76 (5.6) and 92 ml (8.4 L/min). These values compare favorably with prior studies. The transient response of cardiac output following the onset of upright was about twice as fast as in S because of the rapid and almost immediate upsurge in stroke volume. In supine, only heart rate served to augment cardiac output as stroke volume initially fell. The faster initial aortic flow in upright must represent the rapid mobilization of pooled venous blood from the leg veins which more than accounts for the additional volume (184 ml) of blood passing through the aorta during upright compared with supine in the first 20 sec.
Clinically significant change in stroke volume in pulmonary hypertension.
van Wolferen, Serge A; van de Veerdonk, Marielle C; Mauritz, Gert-Jan; Jacobs, Wouter; Marcus, J Tim; Marques, Koen M J; Bronzwaer, Jean G F; Heymans, Martijn W; Boonstra, Anco; Postmus, Pieter E; Westerhof, Nico; Vonk Noordegraaf, Anton
2011-05-01
Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory increased heart rate as is the case for cardiac output. For this reason, stroke volume, which can be measured noninvasively, is an important hemodynamic parameter to monitor during treatment. However, the extent of change in stroke volume that constitutes a clinically significant change is unknown. The aim of this study was to determine the minimal important difference (MID) in stroke volume in PH. One hundred eleven patients were evaluated at baseline and after 1 year of follow-up with a 6-min walk test (6MWT) and cardiac MRI. Using the anchor-based method with 6MWT as the anchor, and the distribution-based method, the MID of stroke volume change could be determined. After 1 year of treatment, there was, on average, a significant increase in stroke volume and 6MWT. The change in stroke volume was related to the change in 6MWT. Using the anchor-based method, an MID of 10 mL in stroke volume was calculated. The distribution-based method resulted in an MID of 8 to 12 mL. Both methods showed that a 10-mL change in stroke volume during follow-up should be considered as clinically relevant. This value can be used to interpret changes in stroke volume during clinical follow-up in PH.
de Simone, Giovanni; Roman, Mary J; De Marco, Marina; Bella, Jonathan N; Izzo, Raffaele; Lee, Elisa T; Devereux, Richard B
2015-09-28
We evaluated the relationship of aortic root dimension (ARD) with flow output and both peripheral and central blood pressure, using multivariable equations predicting ideal sex-specific ARD at a given age and body height. We measured echocardiographic diastolic ARD at the sinuses of Valsalva in 3160 adults (aged 42±16 years, 61% women) from the fourth examination of the Strong Heart Study who were free of prevalent coronary heart disease, and we compared measured data with the theoretical predicted value to calculate a z score. Central blood pressure was estimated by applanation tonometry of the radial artery in 2319 participants. ARD z scores were divided into tertiles representing small, normal, and large ARD. Participants with large ARD exhibited greater prevalence of central obesity and higher levels of inflammatory markers and lipids (0.05
Left ventricular pressure and volume data acquisition and analysis using LabVIEW.
Cassidy, S C; Teitel, D F
1997-03-01
To automate analysis of left ventricular pressure-volume data, we used LabVIEW to create applications that digitize and display data recorded from conductance and manometric catheters. Applications separate data into cardiac cycles, calculate parallel conductance, and calculate indices of left ventricular function, including end-systolic elastance, preload-recruitable stroke work, stroke volume, ejection fraction, stroke work, maximum and minimum derivative of ventricular pressure, heart rate, indices of relaxation, peak filling rate, and ventricular chamber stiffness. Pressure-volume loops can be graphically displayed. These analyses are exported to a text-file. These applications have simplified and automated the process of evaluating ventricular function.
Cardiovascular effects of anti-G suit inflation at 1 and 2 G.
Montmerle, Stéphanie; Linnarsson, Dag
2005-06-01
We sought to determine to which pressure a full-coverage anti-G suit needs to be inflated in order to obtain the same stroke volume during a brief exposure to twice the normal gravity (2 G) as that at 1 G without anti-G suit inflation. Nine sitting subjects were studied at normal (1 G) and during 20 s of exposure to 2 G. They wore anti-G suits, which were inflated at both G-levels to the following target pressures: 0, 70, 140 and 210 mmHg. Stroke volume was computed from cardiac output, which was measured by rebreathing. Heart rate and mean arterial pressure at heart level were recorded. Inflation to 70 mmHg compensated for the decrease in stroke volume and cardiac output caused by hypergravity. Mean arterial pressure at heart level was comparable at 1 G and at 2 G and increased gradually and similarly with inflation (P<0.001) at both gravity levels. Thus, anti-G suits act by increasing both preload and afterload but the two effects counteract each other in terms of cardiac output, so that cardiac output at 2 G is maintained at its 1 G level. This effect is reached already at 70 mmHg of inflation. Greater inflation pressure further increases mean arterial pressure at heart level and compensates for the increased difference in hydrostatic pressure between heart and head in moderate hypergravity.
NASA Astrophysics Data System (ADS)
Grad, Leszek; Murawski, Krzysztof; Sulej, Wojciech
2017-08-01
In the article we presented results obtained during research, which are the continuation of work on the use of artificial neural networks to determine the relationship between the view of the membrane and the stroke volume of the blood chamber of the mechanical prosthetic heart. The purpose of the research was to increase the accuracy of determining the blood chamber volume. Therefore, the study was focused on the technique of the features that the image extraction gives. During research we used the wavelet transform. The achieved results were compared to the results obtained by other previous methods. Tests were conducted on the same mechanical prosthetic heart model used in previous experiments.
DeMarzo, Arthur P; Kelly, Russell F; Calvin, James E
2007-01-01
Early detection of asymptomatic left ventricular systolic dysfunction (LVSD) is beneficial in managing heart failure. Recent studies have cast doubt on the usefulness of cardiac output as an indicator of LVSD. In impedance cardiography (ICG), the dZ/dt waveform has a systolic wave called the E wave. This study looked at measurements of the amplitude and area of the E wave compared with ICG-derived cardiac output, stroke volume, cardiac index, and stroke index as methods of assessing LVSD. ICG data were obtained from patients (n=26) admitted to a coronary care unit. Clinical LVSD severity was stratified into 4 groups (none, mild, moderate, and severe) based on echocardiography data and standard clinical assessment by a cardiologist blinded to ICG data. Statistical analysis showed that the E wave amplitude and area were better indicators of the level of LVSD than cardiac output, stroke volume, cardiac index, or stroke index. ICG waveform analysis has potential as a simple point-of-care test for detecting LVSD in asymptomatic patients at high risk for developing heart failure and for monitoring LVSD in patients being treated for heart failure.
Design of a specialized computer for on-line monitoring of cardiac stroke volume
NASA Technical Reports Server (NTRS)
Webb, J. A., Jr.; Gebben, V. D.
1972-01-01
The design of a specialized analog computer for on-line determination of cardiac stroke volume by means of a modified version of the pressure pulse contour method is presented. The design consists of an analog circuit for computation and a timing circuit for detecting necessary events on the pressure waveform. Readouts of arterial pressures, systolic duration, heart rate, percent change in stroke volume, and percent change in cardiac output are provided for monitoring cardiac patients. Laboratory results showed that computational accuracy was within 3 percent, while animal experiments verified the operational capability of the computer. Patient safety considerations are also discussed.
NASA Astrophysics Data System (ADS)
Hildebrandt, Wulf; Schütze, Harald; Stegemann, J.
Rapid quantification of the human baro-reflex control of heart rate has been achieved on a beat-by-beat basis using a neck-chamber with quick ECG-triggered pressure changes. Referring to recent findings on heart rate and stroke volume, the present study uses this technique to compare cardiac output as well as blood pressure changes in supine and upright position to investigate feedback effects and to confirm postural reflex modifications not revealed by RR-interval changes. A suction profile starting at +40 mmHg and running 7 steps of pressure decrease down to -65 mmHg was examined in 0° and 90° tilting position while beat-by-beat recordings were done of heart rate, stroke volume (impedance-cardiography) and blood pressure (Finapres tm) (n=16). The percentual heart rate decrease failed to be significantly different between positions. A suction-induced stroke volume increase led to a cardiac output almost maintained when supine and significantly increased when upright. A decrease in all blood pressure values was found during suction, except for systolic values in upright position which increased. Conclusively, (a) it is confirmed that different inotropy accounts for the seen gravitational effect on the cardiac output not represented by heart rate; (b) identical suction levels in different positions lead to different stimuli at the carotid receptor. This interference has to be considered in microgravity studies by beat-by-beat measurement of cardiac output and blood pressure.
McGaw, Iain J; McMahon, Brian R
2003-01-01
Decapod crustaceans inhabit aquatic environments that are frequently subjected to changes in salinity and oxygen content. The physiological responses of decapod crustaceans to either salinity or hypoxia are well documented; however, there are many fewer reports on the physiological responses during exposure to these parameters in combination. We investigated the effects of simultaneous and sequential combinations of low salinity and hypoxia on the cardiovascular physiology of the Dungeness crab, Cancer magister. Heart rate, as well as haemolymph flow rates through the anterolateral, hepatic, sternal and posterior arteries were measured using a pulsed-Doppler flowmeter. Summation of flows allowed calculation of cardiac output and division of this by heart rate yielded stroke volume. When hypoxia and low salinity were encountered simultaneously, the observed changes in cardiac properties tended to be a mix of both factors. Hypoxia caused a bradycardia, whereas exposure to low salinity was associated with a tachycardia. However, the hypoxic conditions had the dominant effect on heart rate. Although hypoxia caused an increase in stroke volume of the heart, the low salinity had a more pronounced effect, causing an overall decrease in stroke volume. The patterns of haemolymph flow through the arterial system also varied when hypoxia and low salinity were offered together. The resulting responses were a mix of those resulting from exposure to either parameter alone. When low salinity and hypoxia were offered sequentially, the parameter experienced first tended to have the dominant effect on cardiac function and haemolymph flows. Low salinity exposure was associated with an increase in heart rate, a decrease in stroke volume and cardiac output, and a concomitant decrease in haemolymph flow rates. Subsequent exposure to hypoxic conditions caused a slight decrease in rate, but other cardiovascular variables were largely unaffected. In contrast, when low salinity followed acclimation to hypoxic conditions, apart from an increased heart rate, there were no other cardiovascular changes associated with the low salinity episode. The implications of these changes in cardiovascular dynamics are discussed in relation to physiological mechanisms and the ecology of decapod crustaceans, in hypoxic or low salinity environments. Copyright 2003, Wiley-Liss, Inc.
2006-09-01
NM, Joyner MJ. Influence of increased central venous pressure on baroreflex control of sympathetic activity in humans. Am J Physiol Heart Circ Physiol...Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia Victor A. Convertino, PhD, William H...reduction of SV and change in MSNA during graded central hypovolemia in humans. Methods: After a 12-minute baseline data collection period, 13 men were
Jain, Anil Kumar; Khan, Asma M
2012-09-01
: The potential for fluid overload in large-volume liposuction is a source of serious concern. Fluid management in these patients is controversial and governed by various formulas that have been advanced by many authors. Basically, it is the ratio of what goes into the patient and what comes out. Central venous pressure has been used to monitor fluid therapy. Dynamic parameters, such as stroke volume and pulse pressure variation, are better predictors of volume responsiveness and are superior to static indicators, such as central venous pressure and pulmonary capillary wedge pressure. Stroke volume variation was used in this study to guide fluid resuscitation and compared with one guided by an intraoperative fluid ratio of 1.2 (i.e., Rohrich formula). : Stroke volume variation was used as a guide for intraoperative fluid administration in 15 patients subjected to large-volume liposuction. In another 15 patients, fluid resuscitation was guided by an intraoperative fluid ratio of 1.2. The amounts of intravenous fluid administered in the groups were compared. : The mean amount of fluid infused was 561 ± 181 ml in the stroke volume variation group and 2383 ± 1208 ml in the intraoperative fluid ratio group. The intraoperative fluid ratio when calculated for the stroke volume variation group was 0.936 ± 0.084. All patients maintained hemodynamic parameters (heart rate and systolic, diastolic, and mean blood pressure). Renal and metabolic indices remained within normal limits. : Stroke volume variation-guided fluid application could result in an appropriate amount of intravenous fluid use in patients undergoing large-volume liposuction. : Therapeutic, II.
Evaluation of the pulse-contour method of determining stroke volume in man.
NASA Technical Reports Server (NTRS)
Alderman, E. L.; Branzi, A.; Sanders, W.; Brown, B. W.; Harrison, D. C.
1972-01-01
The pulse-contour method for determining stroke volume has been employed as a continuous rapid method of monitoring the cardiovascular status of patients. Twenty-one patients with ischemic heart disease and 21 patients with mitral valve disease were subjected to a variety of hemodynamic interventions. The pulse-contour estimations, using three different formulas derived by Warner, Kouchoukos, and Herd, were compared with indicator-dilution outputs. A comparison of the results of the two methods for determining stroke volume yielded correlation coefficients ranging from 0.59 to 0.84. The better performing Warner formula yielded a coefficient of variation of about 20%. The type of hemodynamic interventions employed did not significantly affect the results using the pulse-contour method. Although the correlation of the pulse-contour and indicator-dilution stroke volumes is high, the coefficient of variation is such that small changes in stroke volume cannot be accurately assessed by the pulse-contour method. However, the simplicity and rapidity of this method compared to determination of cardiac output by Fick or indicator-dilution methods makes it a potentially useful adjunct for monitoring critically ill patients.
Cardiovascular responses to postural changes: differences with age for women and men
NASA Technical Reports Server (NTRS)
Frey, M. A.; Tomaselli, C. M.; Hoffler, W. G.
1994-01-01
The cardiovascular responses to postural change, and how they are affected by aging, are inadequately described in women. Therefore, the authors examined the influence of age and sex on the responses of blood pressure, cardiac output, heart rate, and other variables to change in posture. Measurements were made after 10 minutes each in the supine, seated, and standing positions in 22 men and 25 women who ranged in age from 21 to 59 years. Several variables differed, both by sex and by age, when subjects were supine. On rising, subjects' diastolic and mean arterial pressures, heart rate, total peripheral resistance (TPR), and thoracic impedance increased; cardiac output, stroke volume, and mean stroke ejection rate decreased; and changes in all variables, except heart rate, were greater from supine to sitting than sitting to standing. The increase in heart rate was greater in the younger subjects, and increases in TPR and thoracic impedance were greater in the older subjects. Stroke volume decreased less, and TPR and thoracic impedance increased more, in the women than in the men. The increase in TPR was particularly pronounced in the older women. These studies show that the cardiovascular responses to standing differ, in some respects, between the sexes and with age. The authors suggest that the sex differences are, in part, related to greater decrease of thoracic blood volume with standing in women than in men, and that the age differences result, in part, from decreased responsiveness of the high-pressure baroreceptor system.
Elementary theory of synchronous arterio-arterial blood pumps
NASA Technical Reports Server (NTRS)
Jones, R. T.; Petscheck, H. E.; Kantrowitz, A. R.
1976-01-01
In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by a formula that considers stroke output of the unaided heart and the increment caused by the pump with a stroke. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological mechanical impedance of the heart. The total effect is, however, independent of the impedance.
Jaski, B E; Fifer, M A; Wright, R F; Braunwald, E; Colucci, W S
1985-01-01
Milrinone is a potent positive inotropic and vascular smooth muscle-relaxing agent in vitro, and therefore, it is not known to what extent each of these actions contributes to the drug's hemodynamic effects in patients with heart failure. In 11 patients with New York Heart Association class III or IV congestive heart failure, incremental intravenous doses of milrinone were administered to determine the dose-response relationships for heart rate, systemic vascular resistance, and inotropic state, the latter measured by peak positive left ventricular derivative of pressure with respect to time (dP/dt). To clarify further the role of a positive inotropic action, the relative effects of milrinone and nitroprusside on left ventricular stroke work and dP/dt were compared in each patient at doses matched to cause equivalent reductions in mean arterial pressure or systemic vascular resistance, indices of left ventricular afterload. Milrinone caused heart rate, stroke volume, and dP/dt to increase, and systemic vascular resistance to decrease in a concentration-related manner. At the two lowest milrinone doses resulting in serum concentrations of 63 +/- 4 and 156 +/- 5 ng/ml, respectively, milrinone caused significant increases in stroke volume and dP/dt, but no changes in systemic vascular resistance or heart rate. At the maximum milrinone dose administered (mean serum concentration, 427 +/- 11 ng/ml), heart rate increased from 92 +/- 4 to 99 +/- 4 bpm (P less than 0.01), mean aortic pressure fell from 82 +/- 3 to 71 +/- 3 mmHg (P less than 0.01), right atrial pressure fell from 15 +/- 2 to 7 +/- 1 mmHg (P less than 0.005), left ventricular end-diastolic pressure fell from 26 +/- 3 to 18 +/- 3 (P less than 0.005), stroke volume index increased from 20 +/- 2 to 30 +/- 2 ml/m2 (P less than 0.005), stroke work index increased from 14 +/- 2 to 21 +/- 2 g X m/m2 (P less than 0.01), and dP/dt increased from 858 +/- 54 to 1,130 +/- 108 mmHg/s (P less than 0.005). When compared with nitroprusside for a matched reduction in mean aortic pressure or systemic vascular resistance, milrinone caused a significantly greater increase in stroke work index at the same or lower left ventricular end-diastolic pressure. Milrinone caused a concentration-related increase in dP/dt (32% increase at maximum milrinone dose), whereas nitroprusside had no effect. These data in patients with severe heart failure indicate that in addition to a vasodilating effect, milrinone exerts a concentration-related positive inotropic action that contributes significantly to the drug's overall hemodynamic effects. The positive inotropic action occurs at drug levels that do not exert significant chronotropic or vasodilator effects. Images PMID:3973022
Instantaneous stroke volume in man during lower body negative pressure /LBNP/
NASA Technical Reports Server (NTRS)
Loeppky, J. A.; Richards, K. L.; Greene, E. R.; Eldridge, M. W.; Hoekenga, D. E.; Venters, M. D.; Luft, U. C.
1982-01-01
Results of an examination of the instantaneous time course of the stroke volume (SV) and cardiac output (Q) in response to the onset and release of -50 torr lower body negative pressure (LBNP) are reported. Six male subjects were sealed into a LBNP box up to the iliac crest while being monitored by echocardiograph for centerlamina blood velocity, fluid displacement, stroke volume, heart rate, and leg volume. Particular use was made of pulsed ultrasonic Doppler velocity meters for measuring the blood velocities and flow dynamics. Measurements were made of the subjects continuously beginning from 20 sec prior to and one min after LBNP onset and release. A linear fall in the SV was observed with LBNP at 49% of the baseline value after 33 sec. A 62% drop, the lowest, was detected after 8 min of LBNP. The leg volume was inversely related to Q for the duration of the experiment.
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Borlaug, Barry A; Melenovsky, Vojtech; Russell, Stuart D; Kessler, Kristy; Pacak, Karel; Becker, Lewis C; Kass, David A
2006-11-14
Nearly half of patients with heart failure have a preserved ejection fraction (HFpEF). Symptoms of exercise intolerance and dyspnea are most often attributed to diastolic dysfunction; however, impaired systolic and/or arterial vasodilator reserve under stress could also play an important role. Patients with HFpEF (n=17) and control subjects without heart failure (n=19) generally matched for age, gender, hypertension, diabetes mellitus, obesity, and the presence of left ventricular hypertrophy underwent maximal-effort upright cycle ergometry with radionuclide ventriculography to determine rest and exercise cardiovascular function. Resting cardiovascular function was similar between the 2 groups. Both had limited exercise capacity, but this was more profoundly reduced in HFpEF patients (exercise duration 180+/-71 versus 455+/-184 seconds; peak oxygen consumption 9.0+/-3.4 versus 14.4+/-3.4 mL x kg(-1) x min(-1); both P<0.001). At matched low-level workload, HFpEF subjects displayed approximately 40% less of an increase in heart rate and cardiac output and less systemic vasodilation (all P<0.05) despite a similar rise in end-diastolic volume, stroke volume, and contractility. Heart rate recovery after exercise was also significantly delayed in HFpEF patients. Exercise capacity correlated with the change in cardiac output, heart rate, and vascular resistance but not end-diastolic volume or stroke volume. Lung blood volume and plasma norepinephrine levels rose similarly with exercise in both groups. HFpEF patients have reduced chronotropic, vasodilator, and cardiac output reserve during exercise compared with matched subjects with hypertensive cardiac hypertrophy. These limitations cannot be ascribed to diastolic abnormalities per se and may provide novel therapeutic targets for interventions to improve exercise capacity in this disorder.
Cameli, M; Bernazzali, S; Lisi, M; Tsioulpas, C; Croccia, M G; Lisi, G; Maccherini, M; Mondillo, S
2012-09-01
Right ventricular (RV) systolic function has a critical role in determining the clinical outcome and the success of using left ventricular assist devices in patients with refractory heart failure. RV deformation analysis by speckle tracking echocardiography (STE) has recently allowed the analysis of RV longitudinal function. Using cardiac catheterization as the reference standard, this study aimed to explore the correlation between RV longitudinal function by STE and RV stroke work index (RVSWI) among patients referred for cardiac transplantation. Right heart catheterization and transthoracic echo-Doppler were simultaneously performed in 47 patients referred for cardiac transplant assessment due to refractory heart failure (ejection fraction 25.1 ± 4.5%). Thermodilution RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. RV longitudinal strain (RVLS) by STE was assessed averaging RV free-wall segments (free-wall RVLS). We also calculated. Tricuspid S' and tricuspid annular plane systolic excursion (TAPSE). No significant correlation was observed for TAPSE on tricuspid S' with RV stroke volume (r = 0.14 and r = 0.06, respectively). A close negative correlation between free-wall RVLS and RVSWI was found (r = -0.82; P < .0001). Furthermore, free-wall RVLS showed the highest diagnostic accuracy (area under the curve of 0.90) with good sensitivity and specificity of 95% and 91%, respectively, to predict depressed RVSWI using a cutoff value less than -11.8%. Among patients referred for heart transplantation, TAPSE and tricuspid S' did not correlate with invasively obtained RVSWI. RV longitudinal deformation analysis by STE correlated with RVSWI, providing a better estimate of RV systolic performance. Copyright © 2012 Elsevier Inc. All rights reserved.
Matsumoto, Kensuke; Onishi, Akira; Yamada, Hirotsugu; Kusunose, Kenya; Suto, Makiko; Hatani, Yutaka; Matsuzoe, Hiroki; Tatsumi, Kazuhiro; Tanaka, Hidekazu; Hirata, Ken-Ichi
2018-05-01
The leg-positive pressure maneuver can safely and noninvasively apply preload stress without increase in total body fluid volume. The purpose of this study was to determine whether preload stress could be useful for risk stratification of patients with heart failure with reduced ejection fraction. For this study, 120 consecutive patients with heart failure with reduced ejection fraction were prospectively recruited. The stroke work index was estimated as product of stroke volume index and mean blood pressure, and the E/e' ratio was calculated to estimate ventricular filling pressure. The echocardiographic parameters were obtained both at rest and during leg-positive pressure stress. During the median follow-up period of 20 months, 30 patients developed adverse cardiovascular events. During preload stress, stroke work index increased significantly (from 3280±1371 to 3857±1581 mm Hg·mL/m 2 ; P <0.001) along with minimal changes in ventricular filling pressure (E/e', from 16±10 to 17±9; P <0.05) in patients without cardiovascular events. However, patients with cardiovascular events showed impairment of Frank-Starling mechanism (stroke work index, from 2863±969 to 2903±1084 mm Hg·mL/m 2 ; P =0.70) and a serious increase in E/e' ratio (from 19±11 to 25±14; P <0.001). Both the patients without contractile reserve and those without diastolic reserve exhibited worse event-free survival than the others ( P <0.001). In a Cox proportional-hazards analysis, the changes in stroke work index (hazard ratio: 0.44 per 500 mm Hg·mL/m 2 increase; P =0.001) and in E/e' (hazard ratio: 2.58 per 5-U increase; P <0.001) were predictors of cardiovascular events. Contractile reserve and diastolic reserve during leg-positive pressure stress are important determinants of cardiovascular outcomes for patients with heart failure with reduced ejection fraction. © 2018 American Heart Association, Inc.
2012-01-01
Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP) is presented, that measures the average stroke volume (SV) for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition) with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo). These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds). The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling caused a pattern over the thorax quite distinct from that of atrial filling. The in-vivo tests of the HCP with LVot Doppler resulted in a Pearson’s correlation of R = 0.892, and Bland-Altman plotting of SV yielded a mean bias of -1.6 ml and 2SD =14.8 ml. Conclusions The results indicate that the HCP was able to track the changes in ventricular stroke volume reliably. Furthermore, the HCP produced ventricular volume-time curves that were consistent with the literature, and may be a diagnostic tool as well. PMID:22900831
Cardiovascular simulator improvement: pressure versus volume loop assessment.
Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Leme, Juliana; Legendre, Daniel; Bock, Eduardo; Lucchi, Julio Cesar
2011-05-01
This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance. In many heart diseases, the stroke volume decreases because of low heart contractility. This pathological situation must be simulated by the PCS in order to evaluate the assistance provided by a ventricular assist device (VAD). The PCS system is automatically controlled by a computer and is an auxiliary tool for VAD control strategies development. This PCS system is according to a Windkessel model where lumped parameters are used for cardiovascular system analysis. Peripheral resistance, arteries compliance, and fluid inertance are simulated. The simulator has an actuator with a roller screw and brushless direct current motor, and the stroke volume is regulated by the actuator displacement. Internal pressure and volume measurements are monitored to obtain the PxV loop. Left chamber internal pressure is directly obtained by pressure transducer; however, internal volume has been obtained indirectly by using a linear variable differential transformer, which senses the diaphragm displacement. Correlations between the internal volume and diaphragm position are made. LabVIEW integrates these signals and shows the pressure versus internal volume loop. The results that have been obtained from the PCS system show PxV loops at different ventricle elastances, making possible the simulation of pathological situations. A preliminary test with a pulsatile VAD attached to PCS system was made. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Kuehnl, Andreas; Tsantilas, Pavlos; Knappich, Christoph; Schmid, Sofie; König, Thomas; Breitkreuz, Thorben; Zimmermann, Alexander; Mansmann, Ulrich; Eckstein, Hans-Henning
2016-11-01
Associations between hospital volume and the risk of stroke or death following carotid endarterectomy (CEA) and carotid artery stenting (CAS) on a national level in Germany were analyzed. Secondary data analysis using microdata from the nationwide statutory German quality assurance database on all surgical or endovascular carotid interventions on the extracranial carotid artery between 2009 and 2014. Hospitals were categorized into empirically determined quintiles according to the annual case volume. The resulting volume thresholds were 10, 25, 46, and 79 for CEA and 2, 6, 12, and 26 for CAS procedures. The primary outcome was any stroke or death before hospital discharge. For risk-adjusted analyses, a multilevel regression model was applied. The analysis included 161 448 CEA and 17 575 CAS procedures. In CEA patients, the crude risk of stroke or death decreased monotonically from 4.2% (95% confidence interval, 3.6%-4.9%) in low-volume hospitals (first quintile 1-10 CEA per year) to 2.1% (2.0%-2.2%) in hospitals providing ≥80 CEA per year (fifth quintile; P<0.001 for trend). The overall risk of any stroke or death in CAS patients was 3.7% (3.5%-4.0%), but no trend on annual volume was seen (P=0.304). Risk-adjusted analyses confirmed a significant inverse relationship between hospital volume (categorized or continuous) and the risk of stroke or death after CEA but not CAS procedures. An inverse volume-outcome relationship in CEA-treated patients was demonstrated. No significant association between hospital volume and the risk of stroke or death was found for CAS. © 2016 American Heart Association, Inc.
Effect of public awareness campaigns on calls to ambulance across Australia.
Bray, Janet E; Straney, Lahn; Barger, Bill; Finn, Judith
2015-05-01
The National Stroke Foundation of Australia has run 12 public awareness campaigns since 2004. Campaign exposure and funding has varied annually and regionally during this time. The aim of this study was to measure the effect of campaigns on calls to ambulance for stroke across Australia in exposed regions (paid or pro bono advertising). All ambulance services in Australia provided monthly ambulance dispatch data between January 2003 and June 2014. We performed multivariable regression to measure the effect of campaign exposure on the volume of stroke-related emergency calls, after controlling for confounders. The final model indicated that 11 of the 12 National Stroke Foundation campaigns were associated with increases in the volume of stroke-related calls (varying between 1% and 9.9%) in regions with exposure to advertising. This increase lasted ≈3 months, with an additional 10.2% relative increase in the volume of the calls in regions with paid advertising. We found no significant additional effect of the campaigns on stroke calls where ambulance services are publicly funded. The National Stroke Foundation stroke awareness campaigns are associated with increases to calls to ambulance for stroke in regions receiving advertising and promotion. Research is now required to examine whether this increased use in ambulance is for appropriate emergencies. © 2015 American Heart Association, Inc.
Dynamic Energy Loss Characteristics in the Native Aortic Valve
NASA Astrophysics Data System (ADS)
Hwai Yap, Choon; Dasi, Laksmi P.; Yoganathan, Ajit P.
2009-11-01
Aortic Valve (AV) stenosis if untreated leads to heart failure. From a mechanics standpoint, heart failure implies failure to generate sufficient mechanical power to overcome energy losses in the circulation. Thus energy efficiency-based measures are direct measures of AV disease severity, which unfortunately is not used in current clinical measures of stenosis severity. We present an analysis of the dynamic rate of energy dissipation through the AV from direct high temporal resolution measurements of flow and pressure drop across the AV in a pulsatile left heart setup. Porcine AV was used and measurements at various conditions were acquired: varying stroke volumes; heart rates; and stenosis levels. Energy dissipation waveform has a distinctive pattern of being skewed towards late systole, attributed to the explosive growth of flow instabilities from adverse pressure gradient. Increasing heart rate and stroke volume increases energy dissipation, but does not alter the normalized shape of the dissipation temporal profile. Stenosis increases energy dissipation and also alters the normalized shape of dissipation waveform with significantly more losses during late acceleration phase. Since stenosis produces a departure from the signature dissipation waveform shape, dynamic energy dissipation analysis can be extended into a clinical tool for AV evaluation.
The human cardiovascular system in the absence of gravity
NASA Technical Reports Server (NTRS)
Bungo, M. W.; Charles, J. B.
1985-01-01
The data collected from a Space Shuttle crew to investigate cardiovascular changes due to microgravity are presented. The experimental procedures which involved preflight, immediate postflight, and one week following postflight echocardiograms of 13 individuals are described. The immediate postflight results reveal a 20 percent decrease in stroke volume, a 16 percent decrease in left ventricular diastolic volume index (LVDVI), no change in systolic volume, blood pressure, or cardiac index, and a 24 percent increase in heart rate. One week later a 17 percent stroke volume increase, a 29 percent increase in cardiac index, and normal blood pressure, and LVDVI were observed. It is concluded that upon reexposure to gravity a readaptation process for the cardiovascular system occurs.
Proposal of a new electromechanical total artificial heart: the TAH Serpentina.
Sauer, I M; Frank, J; Bücherl, E S
1999-03-01
A new type of energy converter for an electro-mechanical total artificial heart (TAH) based on the principle of a unidirectional moving motor is described. Named the TAH Serpentina, the concept consists of 2 major parts, a pendulum shaped movable element fixed on one side using a joint bearing and a special shaped drum cam. Pusher plates are mounted flexibly to the crossbar of the pendulum. A motor drives the special shaped drum cam linked to the pendulum through a ball bearing. The circular motion of the unidirectional moving brushless DC motor is transferred into the linear motion of the pendulum to drive the pusher plates. Using a crossbar with a variable length, the stroke of the pendulum and therefore the displaced blood volume is alterable. To achieve a variable length, an electric driven screw thread or a hydraulic system is possible. Comparable to the natural heart, cardiac output would be determined by frequency and stroke volume.
Bivariate Heritability of Total and Regional Brain Volumes: the Framingham Study
DeStefano, Anita L.; Seshadri, Sudha; Beiser, Alexa; Atwood, Larry D.; Massaro, Joe M.; Au, Rhoda; Wolf, Philip A.; DeCarli, Charles
2009-01-01
Heritability and genetic and environmental correlations of total and regional brain volumes were estimated from a large, generally healthy, community-based sample, to determine if there are common elements to the genetic influence of brain volumes and white matter hyperintensity volume. There were 1538 Framingham Heart Study participants with brain volume measures from quantitative magnetic resonance imaging (MRI) who were free of stroke and other neurological disorders that might influence brain volumes and who were members of families with at least two Framingham Heart Study participants. Heritability was estimated using variance component methodology and adjusting for the components of the Framingham stroke risk profile. Genetic and environmental correlations between traits were obtained from bivariate analysis. Heritability estimates ranging from 0.46 to 0.60, were observed for total brain, white matter hyperintensity, hippocampal, temporal lobe, and lateral ventricular volumes. Moderate, yet significant, heritability was observed for the other measures. Bivariate analyses demonstrated that relationships between brain volume measures, except for white matter hyperintensity, reflected both moderate to strong shared genetic and shared environmental influences. This study confirms strong genetic effects on brain and white matter hyperintensity volumes. These data extend current knowledge by showing that these two different types of MRI measures do not share underlying genetic or environmental influences. PMID:19812462
Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)
NASA Technical Reports Server (NTRS)
Pantalos, George M.; Sharp, M. Keith; Woodruff, Stewart J.; Lorange, Richard D.; Bennett, Thomas E.; Sojka, Jan J.; Lemon, Mark W.
1993-01-01
The recognition and understanding of cardiovascular adaptation to spaceflight has experienced substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented a 15 percent reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume following diuresis and other physiological processes to reduce blood volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been elucidated. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a GAS payload. The experimental apparatus consists of a pneumatically actuated, elliptical artificial ventricle connected to a closed-loop, hydraulic circuit with compliance and resistance elements to create physiologic pressure and flow conditions. The ventricle is instrumented with high-fidelity, acceleration-insensitive, catheter-tip pressure transducers (Millar Instruments) in the apex and base to determine the instantaneous ventricular pressures and (delta)P(sub LV) across the left ventricle (LVP(sub apex)-LVP(sub base). The ventricle is also instrumented with a flow probe and pressure transducers immediately upstream of the inflow valve and downstream of the outflow valve. The experiment will be microprocessor controlled with analog signals stored on the FM data tape recorder. By varying the circulating fluid volume, ventricular function can be determined for varying preload pressures with fixed afterload pressure. Pilot experiments on board the NASA KC-135 aircraft have demonstrated proof-of-concept and provided early support for the proposed hypothesis. A review of the pilot experiments and developmental progress on the GAS version of this experiment will be presented.
Comparison of cardiovascular function during the early hours of bed rest and space flight
NASA Technical Reports Server (NTRS)
Lathers, C. M.; Charles, J. B.
1994-01-01
This paper reviews the cardiovascular responses of six healthy male subjects to 6 hours in a 5 degrees head-down bed rest model of weightlessness, and compares these responses to those obtained when subjects were positioned in head-up tilts of 10 degrees, 20 degrees, and 42 degrees, simulating 1/6, 1/3, and 2/3 G, respectively. Thoracic fluid index, cardiac output, stroke volume, and peak flow were measured using impedance cardiography. Cardiac dimensions and volumes were determined from two-dimensional guided M-mode echocardiograms in the left lateral decubitus position at 0, 2, 4, and 6 hours. Cardiovascular response to a stand test were compared before and after bed rest. The impedance values were related to tilt angle for the first 2 hours of tilt; however, after 3 hours, at all four angles, values began to converge, indicating that cardiovascular homeostatic mechanisms seek a common adapted state, regardless of effective gravity level (tilt angle) up to 2/3 G. Echocardiography revealed that left ventricular end-diastolic and end-systolic volume, stroke volume, ejection fraction, heart rate, and cardiac output had returned to control values by hour 6 for all tilt angles. The lack of a significant immediate change in left ventricular end-diastolic volume, despite decrements in stroke volume (P < .05) and heart rate (not significant), indicates that multiple factors may play a role in the adaptation to simulated hypogravity. The echocardiography data indicated that no angle of tilt, whether head-down or head-up for 4 to 6 hours, mimicked exactly the changes in cardiovascular function recorded after 4 to 6 hours of space flight. Changes in left ventricular end-diastolic volume during space flight and tilt may be similar, but follow a different time course. Nevertheless, head-down tilt at 5 degrees for 6 hours mimics some (stroke volume, systolic and diastolic blood pressure, mean arterial blood pressure, and total resistance), but not all, of the changes occurring in an equivalent time of space flight. The magnitude of the change in the mean heart rate response to standing was greater after six hours of tilt at -5 degrees or 10 degrees. Thus, results from the stand test after 6 hours of bed rest at -5 degrees and 10 degrees, but not at 20 degrees or 42 degrees, are similar to those obtained after space flight.
Blood Volume Response to Physical Activity and Inactivity
2007-07-01
feedback to promote volume excretion and maintain blood volume at its normal baseline level. Physical activity does not alter either arterial pressure or...although this is less clear. The increase in total blood volume then increases the ability to maintain a high stroke volume and a lower heart rate for...compelling evidence that reduced blood vol- ume with age may be a result of a sedentary, high caloric lifestyle rather than the aging process. There
ERIC Educational Resources Information Center
Collins, Heidi L.; Rodenbaugh, David W.; Murphy, Todd P.; Kulics, Jennifer M.; Bailey, Cynthia M.; DiCarlo, Stephen E.
1999-01-01
Presents a laboratory exercise designed to introduce students to the hemodynamic variables (heart rate, stroke volume, total peripheral resistance, and compliance) that alter arterial pressure. (Author/CCM)
Effects of heart rate on experimentally produced mitral regurgitation in dogs.
Yoran, C; Yellin, E L; Hori, M; Tsujioka, K; Laniado, S; Sonnenblick, E H; Frater, R W
1983-12-01
The effects of increasing heart rate (HR) on the hemodynamics of acute mitral regurgitation (MR) were studied in 8 open-chest dogs. Filling volume, regurgitant volume and stroke volume were calculated from electromagnetic probe measurements of mitral and aortic flows. The left atrial-left ventricular systolic pressure gradient was measured with micromanometers. The calculated effective mitral regurgitant orifice area varied from 10 to 128 mm2, with a consequent regurgitant fraction (regurgitant volume/filling volume) of 24 to 62%. After crushing the sinus node, HR was increased stepwise from 90 to 180 beats/min by atrial pacing while maintaining aortic pressure constant. With increasing HR, filling volume, stroke volume, regurgitant volume and regurgitant time decreased; total cardiac output, forward cardiac output, regurgitant output, systolic pressure gradient, regurgitant fraction and the regurgitant orifice did not change; left ventricular end-diastolic pressure decreased; and left atrial v-wave amplitude increased. These results indicate that in acute experimental MR with a wide spectrum of incompetence, the relative distribution of forward and regurgitant flows did not change with large increases in HR. At rates greater than 150 beats/min the atrial contraction occurs early and increases the amplitude of the left atrial v wave. This may contribute to the severity of pulmonary congestion in patients with MR.
Effects of depth and chest volume on cardiac function during breath-hold diving.
Marabotti, Claudio; Scalzini, Alessandro; Cialoni, Danilo; Passera, Mirko; Ripoli, Andrea; L'Abbate, Antonio; Bedini, Remo
2009-07-01
Cardiac response to breath-hold diving in human beings is primarily characterized by the reduction of both heart rate and stroke volume. By underwater Doppler-echocardiography we observed a "restrictive/constrictive" left ventricular filling pattern compatible with the idea of chest squeeze and heart compression during diving. We hypothesized that underwater re-expansion of the chest would release heart constriction and normalize cardiac function. To this aim, 10 healthy male subjects (age 34.2 +/- 10.4) were evaluated by Doppler-echocardiography during breath-hold immersion at a depth of 10 m, before and after a single maximal inspiration from a SCUBA device. During the same session, all subjects were also studied at surface (full-body immersion) and at 5-m depth in order to better characterize the relationship of echo-Doppler pattern with depth. In comparison to surface immersion, 5-m deep diving was sufficient to reduce cardiac output (P = 0.042) and increase transmitral E-peak velocity (P < 0.001). These changes remained unaltered at a 10-m depth. Chest expansion at 10 m decreased left ventricular end-systolic volume (P = 0.024) and increased left ventricular stroke volume (P = 0.024). In addition, it decreased transmitral E-peak velocity (P = 0.012) and increased deceleration time of E-peak (P = 0.021). In conclusion the diving response, already evident during shallow diving (5 m) did not progress during deeper dives (10 m). The rapid improvement in systolic and diastolic function observed after lung volume expansion is congruous with the idea of a constrictive effect on the heart exerted by chest squeeze.
Association between arterial calcifications and nonlacunar and lacunar ischemic strokes.
van Dijk, Anouk C; Fonville, Susanne; Zadi, Taihra; van Hattem, Antonius M G; Saiedie, Ghesrouw; Koudstaal, Peter J; van der Lugt, Aad
2014-03-01
Nonlacunar cerebral infarcts are presumed to be caused by thromboembolism from the heart or extracranial arteries, whereas lacunar infarcts are thought to be caused by small vessel disease. We investigated to what extent arterial calcifications differ between nonlacunar and lacunar ischemic strokes. We studied 820 consecutive patients with transient ischemic attack or ischemic stroke in the anterior circulation who underwent multidetector computed tomography angiography and had no rare cause of stroke. The presence of likely cardioembolic pathogenesis was determined according to the Trial of Org 10172 in Acute Stroke Treatment criteria. The remaining 708 patients were categorized as nonlacunar or lacunar strokes, either transient ischemic attacks or strokes, based on clinical symptoms corrected by brain imaging results. We measured volume of calcifications in the aortic arch, symptomatic extracranial and intracranial carotid artery using multidetector computed tomography angiography. The difference in calcifications between nonlacunar and lacunar strokes was assessed with a multivariable logistic regression analysis. We adjusted for degree of symptomatic carotid artery stenosis and cardiovascular risk factors. We found an independent association between volume of aortic arch calcifications and nonlacunar ischemic strokes (adjusted odds ratio [95% confidence interval], 1.11 [1.02-1.21]). No independent associations between extracranial and intracranial carotid artery calcifications and nonlacunar strokes were present. The only difference we found between nonlacunar and lacunar strokes was a higher calcification volume in the aortic arch in nonlacunar strokes. Our findings only partially confirm the notion of distinct etiologies and suggest that the potential role of other plaque components, plaque morphology, and aortic arch calcifications in ischemic stroke subtypes awaits further evaluation.
Pieterman, Elise D; Budde, Ricardo P J; Robbers-Visser, Daniëlle; van Domburg, Ron T; Helbing, Willem A
2017-09-01
Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital heart disease with conventional analysis. © 2017 Wiley Periodicals, Inc.
Zhang, Jie-Min; Liu, Xiao-Cheng; Liu, Zhi-Gang; Zhao, Long; Yang, Li; Liu, Tian-Wen; He, Guo-Wei
2015-11-24
Previously designed intra-thoracic paraaortic counterpulsation device has limited stroke volume and may depress the lung to cause complications. The purpose of this study was to evaluate the hemodynamic effects of an extra-thoracic paraaortic counterpulsation device (ETPACD) in comparison to intraaortic balloon pump (IABP) in an animal model with acute heart failure. The acute heart failure model was successfully induced by snaring branch of anterior descending coronary artery in sheep (weighting, 38-50 kg, n = 8). The ETPACD is a single port, 65-ml stroke volume blood chamber designed to be connected to descending aorta through a valveless graft and placed extra-thorax. In comparison, a standard clinical 40-ml IABP was placed in the descending aorta. The hemodynamic indices of both devices were recorded during counterpulsation assistance. Two of the sheep were allowed to survive for 1 week to examine the prolonged effect. Both ETPACD and IABP increased cardiac output with higher effect of ETPACD (13.52 % vs. 8.19 % in IABP, P < 0.05) and on mean diastolic aortic pressure (26.73 % vs. 12.58 % in IABP, P < 0.01). Both ETPACD and IABP also produced a greater reduction in left ventricular end-diastolic pressure (26.77 % vs. 23.08 %, P > 0.05). The ETPACD increased left carotid artery flow more significantly the IABP (18.00 % vs. 9.19 % , P < 0.05). In two of the sheep allowed to survive for 1 week, the device worked well with no complications and there was no thrombus formation in the chamber of ETPACD. This study demonstrated that both ETPACD and IABP provided benefit of circulatory support in acute heart failure with better effect on hemodynamic parameters provided by ETPACD. Therefore, ETPACD with theoretical larger stroke volume may become a promising counterpulsation device for treatment of heart failure.
Henry, Isaac C; Bernstein, Donald P; Banet, Matt J
2012-01-01
Stroke volume (SV) is the quantity of blood ejected by the cardiac ventricles per each contraction. When SV is multiplied by heart rate, cardiac output is the result. Cardiac output (CO), in conjunction with hemoglobin concentration and arterial oxygen saturation are the cornerstones of oxygen transport. Measurement of CO is important, especially in sick humans suffering from decompensated heart disease and systemic diseases affecting the contractility or loading conditions of the heart. Although reasonably accurate invasive cardiac output methods are available, their use is restricted to those individuals hospitalized in the intensive care units. Thus, a robust noninvasive alternative is considered desirable. Impedance cardiography (ICG) is one such method, but in patients with severe heart disease and/or excess extravascular lung water, the method is inaccurate. This paper concerns the introduction of a new method, transbrachial electrical bioimpedance velocimetry (TBEV). The technique involves passage of a constant magnitude, high frequency, and low amperage ac from the upper arm to the antecubital fossa. In all other respects, the operational aspects of TBEV are consistent with ICG. There is good evidence suggesting that the TBEV waveform and its derivatives are generated by blood resistivity changes only.
Cardiovascular adaptation to extrauterine life after intrauterine growth restriction.
Rodriguez-Guerineau, Luciana; Perez-Cruz, Miriam; Gomez Roig, María D; Cambra, Francisco J; Carretero, Juan; Prada, Fredy; Gómez, Olga; Crispi, Fátima; Bartrons, Joaquim
2018-02-01
Introduction The adaptive changes of the foetal heart in intrauterine growth restriction can persist postnatally. Data regarding its consequences for early circulatory adaptation to extrauterine life are scarce. The aim of this study was to assess cardiac morphometry and function in newborns with late-onset intrauterine growth restriction to test the hypothesis that intrauterine growth restriction causes cardiac shape and functional changes at birth. A comprehensive echocardiographic study was performed in 25 neonates with intrauterine growth restriction and 25 adequate-for-gestational-age neonates. Compared with controls, neonates with intrauterine growth restriction had more globular ventricles, lower longitudinal tricuspid annular motion, and higher left stroke volume without differences in the heart rate. Neonates with intrauterine growth restriction also showed subclinical signs of diastolic dysfunction in the tissue Doppler imaging with lower values of early (e') diastolic annular peak velocities in the septal annulus. Finally, the Tei index in the tricuspid annulus was higher in the intrauterine growth restriction group. Neonates with history of intrauterine growth restriction showed cardiac remodelling and signs of systolic and diastolic dysfunction. Overall, there was a significant tendency to worse cardiac function results in the right heart. The adaptation to extrauterine life occurred with more globular hearts, higher stroke volumes but a similar heart rate compared to adequate-for-gestational-age neonates.
Cardiorespiratory interactions in humans and animals: Rhythms for life.
Elstad, Maja; O'Callaghan, Erin L; Smith, Alexander J; Ben-Tal, A; Ramchandra, Rohit
2018-03-09
The cardiorespiratory system exhibits oscillations from a range of sources. One of the most studied oscillations is heart rate variability, which is thought to be beneficial and can serve as an index of a healthy cardiovascular system. Heart rate variability is dampened in many diseases including depression, autoimmune diseases, hypertension and heart failure. Thus, understanding the interactions that lead to heart rate variability, and its physiological role, could help with prevention, diagnosis and treatment of cardiovascular diseases. In this review we consider three types of cardiorespiratory interactions; Respiratory Sinus Arrhythmia - variability in heart rate at the frequency of breathing, Cardioventilatory Coupling - synchronization between the heart beat and the onset of inspiration, and Respiratory Stroke Volume Synchronization - constant phase difference between the right and the left stroke volumes over one respiratory cycle. While the exact physiological role of these oscillations continues to be debated, the redundancies in the mechanisms responsible for its generation and its strong evolutionary conservation point to the importance of cardiorespiratory interactions. The putative mechanisms driving cardiorespiratory oscillations as well as the physiological significance of these oscillations will be reviewed. We suggest that cardiorespiratory interactions have the capacity to both dampen the variability in systemic blood flow as well as improve the efficiency of work done by the heart while maintaining physiological levels of arterial CO 2 . Given that reduction in variability is a prognostic indicator of disease, we argue that restoration of this variability via pharmaceutical or device-based approaches may be beneficial in prolonging life.
Flow dynamics and energy efficiency of flow in the left ventricle during myocardial infarction.
Vasudevan, Vivek; Low, Adriel Jia Jun; Annamalai, Sarayu Parimal; Sampath, Smita; Poh, Kian Keong; Totman, Teresa; Mazlan, Muhammad; Croft, Grace; Richards, A Mark; de Kleijn, Dominique P V; Chin, Chih-Liang; Yap, Choon Hwai
2017-10-01
Cardiovascular disease is a leading cause of death worldwide, where myocardial infarction (MI) is a major category. After infarction, the heart has difficulty providing sufficient energy for circulation, and thus, understanding the heart's energy efficiency is important. We induced MI in a porcine animal model via circumflex ligation and acquired multiple-slice cine magnetic resonance (MR) images in a longitudinal manner-before infarction, and 1 week (acute) and 4 weeks (chronic) after infarction. Computational fluid dynamic simulations were performed based on MR images to obtain detailed fluid dynamics and energy dynamics of the left ventricles. Results showed that energy efficiency flow through the heart decreased at the acute time point. Since the heart was observed to experience changes in heart rate, stroke volume and chamber size over the two post-infarction time points, simulations were performed to test the effect of each of the three parameters. Increasing heart rate and stroke volume were found to significantly decrease flow energy efficiency, but the effect of chamber size was inconsistent. Strong complex interplay was observed between the three parameters, necessitating the use of non-dimensional parameterization to characterize flow energy efficiency. The ratio of Reynolds to Strouhal number, which is a form of Womersley number, was found to be the most effective non-dimensional parameter to represent energy efficiency of flow in the heart. We believe that this non-dimensional number can be computed for clinical cases via ultrasound and hypothesize that it can serve as a biomarker for clinical evaluations.
Warning Signs of Heart Attack, Stroke and Cardiac Arrest
... a Heart Attack WARNING SIGNS OF HEART ATTACK, STROKE & CARDIAC ARREST HEART ATTACK WARNING SIGNS CHEST DISCOMFORT ... nausea or lightheadedness. Learn more about heart attack STROKE WARNING SIGNS Spot a stroke F.A.S.T.: - ...
Leithner, Christoph; Füchtemeier, Martina; Jorks, Devi; Mueller, Susanne; Dirnagl, Ulrich; Royl, Georg
2015-11-01
Despite standardization of experimental stroke models, final infarct sizes after middle cerebral artery occlusion (MCAO) vary considerably. This introduces uncertainties in the evaluation of drug effects on stroke. Magnetic resonance imaging may detect variability of surgically induced ischemia before treatment and thus improve treatment effect evaluation. MCAO of 45 and 90 minutes induced brain infarcts in 83 mice. During, and 3 and 6 hours after MCAO, we performed multiparametric magnetic resonance imaging. We evaluated time courses of cerebral blood flow, apparent diffusion coefficient (ADC), T1, T2, accuracy of infarct prediction strategies, and impact on statistical evaluation of experimental stroke studies. ADC decreased during MCAO but recovered completely on reperfusion after 45 and partially after 90-minute MCAO, followed by a secondary decline. ADC lesion volumes during MCAO or at 6 hours after MCAO largely determined final infarct volumes for 90 but not for 45 minutes MCAO. The majority of chance findings of final infarct volume differences in random group allocations of animals were associated with significant differences in early ADC lesion volumes for 90, but not for 45-minute MCAO. The prediction accuracy of early magnetic resonance imaging for infarct volumes depends on timing of magnetic resonance imaging and MCAO duration. Variability of the posterior communicating artery in C57Bl6 mice contributes to differences in prediction accuracy between short and long MCAO. Early ADC imaging may be used to reduce errors in the interpretation of post MCAO treatment effects on stroke volumes. © 2015 American Heart Association, Inc.
Systolic and Diastolic Left Ventricular Mechanics during and after Resistance Exercise.
Stöhr, Eric J; Stembridge, Mike; Shave, Rob; Samuel, T Jake; Stone, Keeron; Esformes, Joseph I
2017-10-01
To improve the current understanding of the impact of resistance exercise on the heart, by examining the acute responses of left ventricular (LV) strain, twist, and untwisting rate ("LV mechanics"). LV echocardiographic images were recorded in systole and diastole before, during and immediately after (7-12 s) double-leg press exercise at two intensities (30% and 60% of maximum strength, one-repetition maximum). Speckle tracking analysis generated LV strain, twist, and untwisting rate data. Additionally, beat-by-beat blood pressure was recorded and systemic vascular resistance (SVR) and LV wall stress were calculated. Responses in both exercise trials were statistically similar (P > 0.05). During effort, stroke volume decreased, whereas SVR and LV wall stress increased (P < 0.05). Immediately after effort, stroke volume returned to baseline, whereas SVR and wall stress decreased (P < 0.05). Similarly, acute exercise was accompanied by a significant decrease in systolic parameters of LV muscle mechanics (P < 0.05). However, diastolic parameters, including LV untwisting rate, were statistically unaltered (P > 0.05). Immediately after exercise, systolic LV mechanics returned to baseline levels (P < 0.05) but LV untwisting rate increased significantly (P < 0.05). A single, acute bout of double-leg press resistance exercise transiently reduces systolic LV mechanics, but increases diastolic mechanics after exercise, suggesting that resistance exercise has a differential impact on systolic and diastolic heart muscle function. The findings may explain why acute resistance exercise has been associated with reduced stroke volume but chronic exercise training may result in increased LV volumes.
Motion-aware stroke volume quantification in 4D PC-MRI data of the human aorta.
Köhler, Benjamin; Preim, Uta; Grothoff, Matthias; Gutberlet, Matthias; Fischbach, Katharina; Preim, Bernhard
2016-02-01
4D PC-MRI enables the noninvasive measurement of time-resolved, three-dimensional blood flow data that allow quantification of the hemodynamics. Stroke volumes are essential to assess the cardiac function and evolution of different cardiovascular diseases. The calculation depends on the wall position and vessel orientation, which both change during the cardiac cycle due to the heart muscle contraction and the pumped blood. However, current systems for the quantitative 4D PC-MRI data analysis neglect the dynamic character and instead employ a static 3D vessel approximation. We quantify differences between stroke volumes in the aorta obtained with and without consideration of its dynamics. We describe a method that uses the approximating 3D segmentation to automatically initialize segmentation algorithms that require regions inside and outside the vessel for each temporal position. This enables the use of graph cuts to obtain 4D segmentations, extract vessel surfaces including centerlines for each temporal position and derive motion information. The stroke volume quantification is compared using measuring planes in static (3D) vessels, planes with fixed angulation inside dynamic vessels (this corresponds to the common 2D PC-MRI) and moving planes inside dynamic vessels. Seven datasets with different pathologies such as aneurysms and coarctations were evaluated in close collaboration with radiologists. Compared to the experts' manual stroke volume estimations, motion-aware quantification performs, on average, 1.57% better than calculations without motion consideration. The mean difference between stroke volumes obtained with the different methods is 7.82%. Automatically obtained 4D segmentations overlap by 85.75% with manually generated ones. Incorporating motion information in the stroke volume quantification yields slight but not statistically significant improvements. The presented method is feasible for the clinical routine, since computation times are low and essential parts run fully automatically. The 4D segmentations can be used for other algorithms as well. The simultaneous visualization and quantification may support the understanding and interpretation of cardiac blood flow.
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.
Stroke Location Is an Independent Predictor of Cognitive Outcome.
Munsch, Fanny; Sagnier, Sharmila; Asselineau, Julien; Bigourdan, Antoine; Guttmann, Charles R; Debruxelles, Sabrina; Poli, Mathilde; Renou, Pauline; Perez, Paul; Dousset, Vincent; Sibon, Igor; Tourdias, Thomas
2016-01-01
On top of functional outcome, accurate prediction of cognitive outcome for stroke patients is an unmet need with major implications for clinical management. We investigated whether stroke location may contribute independent prognostic value to multifactorial predictive models of functional and cognitive outcomes. Four hundred twenty-eight consecutive patients with ischemic stroke were prospectively assessed with magnetic resonance imaging at 24 to 72 hours and at 3 months for functional outcome using the modified Rankin Scale and cognitive outcome using the Montreal Cognitive Assessment (MoCA). Statistical maps of functional and cognitive eloquent regions were derived from the first 215 patients (development sample) using voxel-based lesion-symptom mapping. We used multivariate logistic regression models to study the influence of stroke location (number of eloquent voxels from voxel-based lesion-symptom mapping maps), age, initial National Institutes of Health Stroke Scale and stroke volume on modified Rankin Scale and MoCA. The second part of our cohort was used as an independent replication sample. In univariate analyses, stroke location, age, initial National Institutes of Health Stroke Scale, and stroke volume were all predictive of poor modified Rankin Scale and MoCA. In multivariable analyses, stroke location remained the strongest independent predictor of MoCA and significantly improved the prediction compared with using only age, initial National Institutes of Health Stroke Scale, and stroke volume (area under the curve increased from 0.697-0.771; difference=0.073; 95% confidence interval, 0.008-0.155). In contrast, stroke location did not persist as independent predictor of modified Rankin Scale that was mainly driven by initial National Institutes of Health Stroke Scale (area under the curve going from 0.840 to 0.835). Similar results were obtained in the replication sample. Stroke location is an independent predictor of cognitive outcome (MoCA) at 3 months post stroke. © 2015 American Heart Association, Inc.
NASA Astrophysics Data System (ADS)
Convertino, V. A.; Koenig, S. C.; Krotov, V. P.; Fanton, J. W.; Korolkov, V. I.; Trambovetsky, E. V.; Ewert, D. L.; Truzhennikov, A.; Latham, R. D.
Central circulatory hemodynamic responses were measured before and during the initial 9 days of a 12-day 10 ° head-down tilt (HDT) in 4 flight-sized juvenile rhesus monkeys who were surgically instrumented with a variety of intrathoracic catheters and blood flow sensors to assess the effects of simulated microgravity on central circulatory hemodynamics. Each subject underwent measurements of aortic and left ventricular pressures, and aortic flow before and during HDT as well as during a passive head-up postural test before and after HDT. Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure were measured, and dP/dt and left ventricular elastance was calculated from hemodynamic measurements. The postural test consisted of 5 min of supine baseline control followed by 5 minutes of 90 ° upright tilt (HUT). Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure showed no consistent alterations during HDT. Left ventricular elastance was reduced in all animals throughout HDT, indicating that cardiac compliance was increased. HDT did not consistently alter left ventricular +dP/dt, indicating no change in cardiac contractility. Heart rate during the post-HDT HUT postural test was elevated compared to pre-HDT while post-HDT cardiac output was decreased by 52% as a result of a 54% reduction in stroke volume throughout HUT. Results from this study using an instrumented rhesus monkey suggest that exposure to microgravity may increase ventricular compliance without alterating cardiac contractility. Our project supported the notion that an invasively-instrumented animal model should be viable for use in spaceflight cardiovascular experiments to assess potential changes in myocardial function and cardiac compliance.
NASA Technical Reports Server (NTRS)
Convertino, V. A.; Koenig, S. C.; Krotov, V. P.; Fanton, J. W.; Korolkov, V. I.; Trambovetsky, E. V.; Ewert, D. L.; Truzhennikov, A.; Latham, R. D.
1998-01-01
Central circulatory hemodynamic responses were measured before and during the initial 9 days of a 12-day 10 degrees head-down tilt (HDT) in 4 flight-sized juvenile rhesus monkeys who were surgically instrumented with a variety of intrathoracic catheters and blood flow sensors to assess the effects of simulated microgravity on central circulatory hemodynamics. Each subject underwent measurements of aortic and left ventricular pressures, and aortic flow before and during HDT as well as during a passive head-up postural test before and after HDT. Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure were measured, and dP/dt and left ventricular elastance was calculated from hemodynamic measurements. The postural test consisted of 5 min of supine baseline control followed by 5 minutes of 90 degrees upright tilt (HUT). Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure showed no consistent alterations during HDT. Left ventricular elastance was reduced in all animals throughout HDT, indicating that cardiac compliance was increased. HDT did not consistently alter left ventricular +dP/dt, indicating no change in cardiac contractility. Heart rate during the post-HDT HUT postural test was elevated compared to pre-HDT while post-HDT cardiac output was decreased by 52% as a result of a 54% reduction in stroke volume throughout HUT. Results from this study using an instrumented rhesus monkey suggest that exposure to microgravity may increase ventricular compliance without alternating cardiac contractility. Our project supported the notion that an invasively-instrumented animal model should be viable for use in spaceflight cardiovascular experiments to assess potential changes in myocardial function and cardiac compliance.
Lim, Ki Moo; Lee, Jeong Sang; Gyeong, Min-Soo; Choi, Jae-Sung; Choi, Seong Wook
2013-01-01
To quantify the reduction in workload during intra-aortic balloon pump (IABP) therapy, indirect parameters are used, such as the mean arterial pressure during diastole, product of heart rate and peak systolic pressure, and pressure-volume area. Therefore, we investigated the cardiac energy consumption during IABP therapy using a cardiac electromechanics model. We incorporated an IABP function into a previously developed electromechanical model of the ventricle with a lumped model of the circulatory system and investigated the cardiac energy consumption at different IABP inflation volumes. When the IABP was used at inflation level 5, the cardiac output and stroke volume increased 11%, the ejection fraction increased 21%, the stroke work decreased 1%, the mean arterial pressure increased 10%, and the ATP consumption decreased 12%. These results show that although the ATP consumption is decreased significantly, stroke work is decreased only slightly, which indicates that the IABP helps the failed ventricle to pump blood efficiently. PMID:23341718
Lim, Ki Moo; Lee, Jeong Sang; Gyeong, Min-Soo; Choi, Jae-Sung; Choi, Seong Wook; Shim, Eun Bo
2013-01-01
To quantify the reduction in workload during intra-aortic balloon pump (IABP) therapy, indirect parameters are used, such as the mean arterial pressure during diastole, product of heart rate and peak systolic pressure, and pressure-volume area. Therefore, we investigated the cardiac energy consumption during IABP therapy using a cardiac electromechanics model. We incorporated an IABP function into a previously developed electromechanical model of the ventricle with a lumped model of the circulatory system and investigated the cardiac energy consumption at different IABP inflation volumes. When the IABP was used at inflation level 5, the cardiac output and stroke volume increased 11%, the ejection fraction increased 21%, the stroke work decreased 1%, the mean arterial pressure increased 10%, and the ATP consumption decreased 12%. These results show that although the ATP consumption is decreased significantly, stroke work is decreased only slightly, which indicates that the IABP helps the failed ventricle to pump blood efficiently.
The Minnesota Heart Disease and Stroke Prevention Plan 2011-2020.
Shanedling, Stanton; Mehelich, Mary Jo; Peacock, James
2012-05-01
Although Minnesota is known as a heart-healthy state, heart disease and stroke are still among the leading causes of death for people living here, especially those in certain racial and ethnic groups. To address this concern and reduce the overall incidence of heart disease and stroke, the Minnesota Department of Health's Heart Disease and Stroke Prevention Unit led an effortto create the Heart Disease and Stroke Prevention Plan 2011-2020. This article describes the plan's fundamentals and some of its recommendations.
Yoshida, Kuniko; Obokata, Masaru; Kurosawa, Koji; Sorimachi, Hidemi; Kurabayashi, Masahiko; Negishi, Kazuaki
2016-10-01
Embolic stroke in atrial fibrillation is more prevalent in women than in men, yet the basis for this difference remains unclear. This study seeks to elucidate whether there are any sex differences in the relationships between stroke risk (CHADS 2 score, CHA 2 DS 2 -VASc score without a sex category, and estimated stroke rate) and left atrial (LA) anatomy or mechanics in patients with atrial fibrillation. LA emptying fraction and global peak atrial longitudinal strain were assessed in 414 subjects with paroxysmal or persistent atrial fibrillation (156 women and 258 men). Linear regression models with an interaction term were performed to test the effect of sex difference on associations between the embolic risk and LA function or anatomy. Sensitivity analyses were performed in 228 age, heart rate, and rhythm-matched subjects (114 women and men). Women were older and had larger LA volumes and lower LA mechanics than men. Significant negative association between the CHADS 2 score and LA emptying fraction was only demonstrated in women with a significant interaction between sexes. Similar significant interactions were found in global peak atrial longitudinal strain but not in LA volume. These findings were corroborated in the comparisons against CHA 2 DS 2 -VASc score without a sex category and the estimated stroke rate. Sensitivity analyses in the matched subgroup also confirmed the robustness of these sex differences in LA emptying fraction, but less so in global peak atrial longitudinal strain. Significant sex interactions on the association between global LA function and risk stratification schemes exist, which may be a reason for the higher prevalence of embolic stroke in women. © 2016 American Heart Association, Inc.
ERIC Educational Resources Information Center
Heusner, A. A.; Tracy, M. L.
1980-01-01
Describes a simple hydraulic analog which allows students to explore some physical aspects of the cardiovascular system and provides them with a means to visualize and conceptualize these basic principles. Simulates the behavior of arterial pressure in response to changes in heart rate, stroke volume, arterial compliance, and peripheral…
Malliaras, Konstantinos; Charitos, Efstratios; Diakos, Nikolaos; Pozios, Iraklis; Papalois, Apostolos; Terrovitis, John; Nanas, John
2014-12-01
We investigated the effects of intra-aortic balloon pump (IABP) counterpulsation on left ventricular (LV) contractility, relaxation, and energy consumption and probed the underlying physiologic mechanisms in 12 farm pigs, using an ischemia-reperfusion model of acute heart failure. During both ischemia and reperfusion, IABP support unloaded the LV, decreased LV energy consumption (pressure-volume area, stroke work), and concurrently improved LV mechanical performance (ejection fraction, stroke volume, cardiac output). During reperfusion exclusively, IABP also improved LV relaxation (tau) and contractility (Emax, PRSW). The beneficial effects of IABP support on LV relaxation and contractility correlated with IABP-induced augmentation of coronary blood flow. In conclusion, we find that during both ischemia and reperfusion, IABP support optimizes LV energetic performance (decreases energy consumption and concurrently improves mechanical performance) by LV unloading. During reperfusion exclusively, IABP support also improves LV contractility and active relaxation, possibly due to a synergistic effect of unloading and augmentation of coronary blood flow.
NASA Technical Reports Server (NTRS)
Lance, V. Q.; Spodick, D. H.
1976-01-01
Experiments were conducted on healthy human subjects to determine HR-LVET (Heart Rate-Left Ventricular Ejection Time) regression relations in different postures, including tilt, and during isometric exercise. The subjects were tested in the resting state in supine and sitting positions, during isometric handgrip in supine and sitting positions and during 70 deg headup tilt. The recordings included a bipolar electrocardiogram and a right external carotid pulse curve. Comparison of the HR-LVET relation for the conditions under analysis revealed differences among the respective regression equations, which can be explained by the well-established differences in stroke volume and ejection rate among these states. These differences appear to account for the fact that under conditions in which stroke volume variations should be the major determinant, slopes will be similar but intercepts will vary. Since substantial differences among intercepts are observed, caution should be exercised whenever the intercept factor is used to predict LVET for HR.
Time and diffusion lesion size in major anterior circulation ischemic strokes.
Hakimelahi, Reza; Vachha, Behroze A; Copen, William A; Papini, Giacomo D E; He, Julian; Higazi, Mahmoud M; Lev, Michael H; Schaefer, Pamela W; Yoo, Albert J; Schwamm, Lee H; González, R Gilberto
2014-10-01
Major anterior circulation ischemic strokes caused by occlusion of the distal internal carotid artery or proximal middle cerebral artery or both account for about one third of ischemic strokes with mostly poor outcomes. These strokes are treatable by intravenous tissue-type plasminogen activator and endovascular methods. However, dynamics of infarct growth in these strokes are poorly documented. The purpose was to help understand infarct growth dynamics by measuring acute infarct size with diffusion-weighted imaging (DWI) at known times after stroke onset in patients with documented internal carotid artery/middle cerebral artery occlusions. Retrospectively, we included 47 consecutive patients with documented internal carotid artery/middle cerebral artery occlusions who underwent DWI within 30 hours of stroke onset. Prospectively, 139 patients were identified using the same inclusion criteria. DWI lesion volumes were measured and correlated to time since stroke onset. Perfusion data were reviewed in those who underwent perfusion imaging. Acute infarct volumes ranged from 0.41 to 318.3 mL. Infarct size and time did not correlate (R2=0.001). The majority of patients had DWI lesions that were <25% the territory at risk (<70 mL) whether they were imaged <8 or >8 hours after stroke onset. DWI lesions corresponded to areas of greatly reduced perfusion. Poor correlation between infarct volume and time after stroke onset suggests that there are factors more powerful than time in determining infarct size within the first 30 hours. The observations suggest that highly variable cerebral perfusion via the collateral circulation may primarily determine infarct growth dynamics. If verified, clinical implications include the possibility of treating many patients outside traditional time windows. © 2014 American Heart Association, Inc.
Risk of hemorrhage in ischemic stroke and its relationship with cerebral microbleeds.
Ozbek, Damla; Ozturk Tan, Ozlem; Ekinci, Gazanfer; Midi, Ipek
2018-05-01
Stroke is an important public health problem in most countries. Therefore, the treatment of stroke and its complications is important. Intracerebral hemorrhage is one of the complications of ischemic stroke. This study aimed to investigate the risk of hemorrhage in patients with acute ischemic stroke and prospectively study its relationship with cerebral microbleeds (MBs) using susceptibility-weighted imaging (SWI) that is a magnetic resonance imaging (MRI) sequence. Patients with acute ischemic stroke were included. Those who underwent treatment with tissue plasminogen activator were excluded. The patients were analyzed according to their risk factors for stroke and their relationship with intracerebral hemorrhage. A total of 148 patients were included. Of these, 41 (28%) had hemorrhages in the ischemic area. The mean waist circumferences, left atrium diameter, and heart rate in these patients were higher than those in patients without hemorrhage. MBs were detected in 66 patients (44.6%) using SWI, and there was no significant relationship with the presence of hemorrhage. Intracerebral hemorrhages were significantly associated with the volume and localization of infarcts. Intracerebral hemorrhage in patients with acute ischemic stroke within the first 7 days after stroke onset was related to their waist circumference as well as the volume and localization of the infarct. However, there was no relationship found between the risk of hemorrhage and MBs using SWI. Copyright © 2018 Elsevier B.V. All rights reserved.
Cardiovascular consequences of bed rest: effect on maximal oxygen uptake
NASA Technical Reports Server (NTRS)
Convertino, V. A.
1997-01-01
Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake and reserve capacity to perform physical work.
Banner, N; Guz, A; Heaton, R; Innes, J A; Murphy, K; Yacoub, M
1988-01-01
1. Ventilatory and cardiovascular responses to the onset of voluntary and electrically induced leg exercise were studied in six patients following heart transplantation and five following heart-lung transplantation; the results were compared between the patient groups and also with responses from a group of normal subjects. 2. Oxygen consumption, carbon dioxide production and ventilation and its components were measured over two 30 s periods prior to, and two 30 s periods following, the onset of exercise. Relative changes in stroke volume and cardiac output were derived from ensemble-averaged Doppler measurements of ascending aortic blood velocity over the same 30 s periods. 3. None of the groups of subjects showed any significant differences in responses to voluntary exercise compared to electrically induced exercise of similar work pattern and intensity. 4. Compared to normal controls, the transplanted subjects showed higher resting heart rates which did not increase at the onset of exercise; stroke volume increased, but less than in the normal subjects. The resulting cardiac output increases in the transplanted subjects were minimal compared to the normal subjects. 5. Ventilation and oxygen uptake increased immediately and with similar magnitude in all three groups. 6. These results show that in the same individual it is possible to have an appropriate ventilatory response to the onset of exercise in the presumed absence of a normal corticospinal input to the exercising muscles (electrically induced exercise) and afferent neural information from the lungs and heart, and in the absence of a normal circulatory response to exercise. The mechanisms underlying this ventilatory response remain undetermined. PMID:3136247
Brain-Heart Interaction: Cardiac Complications After Stroke.
Chen, Zhili; Venkat, Poornima; Seyfried, Don; Chopp, Michael; Yan, Tao; Chen, Jieli
2017-08-04
Neurocardiology is an emerging specialty that addresses the interaction between the brain and the heart, that is, the effects of cardiac injury on the brain and the effects of brain injury on the heart. This review article focuses on cardiac dysfunction in the setting of stroke such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage. The majority of post-stroke deaths are attributed to neurological damage, and cardiovascular complications are the second leading cause of post-stroke mortality. Accumulating clinical and experimental evidence suggests a causal relationship between brain damage and heart dysfunction. Thus, it is important to determine whether cardiac dysfunction is triggered by stroke, is an unrelated complication, or is the underlying cause of stroke. Stroke-induced cardiac damage may lead to fatality or potentially lifelong cardiac problems (such as heart failure), or to mild and recoverable damage such as neurogenic stress cardiomyopathy and Takotsubo cardiomyopathy. The role of location and lateralization of brain lesions after stroke in brain-heart interaction; clinical biomarkers and manifestations of cardiac complications; and underlying mechanisms of brain-heart interaction after stroke, such as the hypothalamic-pituitary-adrenal axis; catecholamine surge; sympathetic and parasympathetic regulation; microvesicles; microRNAs; gut microbiome, immunoresponse, and systemic inflammation, are discussed. © 2017 American Heart Association, Inc.
O'Neal, Wesley T; Qureshi, Waqas T; Judd, Suzanne E; Meschia, James F; Howard, Virginia J; Howard, George; Soliman, Elsayed Z
2015-12-01
The association between resting heart rate and ischemic stroke remains unclear. To examine the association between resting heart rate and ischemic stroke. A total of 24 730 participants (mean age: 64 ± 9·3 years; 59% women; 41% blacks) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study who were free of stroke at the time of enrollment (2003-2007) were included in this analysis. Resting heart rate was determined from baseline electrocardiogram data. Heart rate was examined as a continuous variable per 10 bpm increase and also as a categorical variable using tertiles ( <61 bpm, 61 to 70 bpm, and >70 bpm). First-time ischemic stroke events were identified during follow-up and adjudicated by physician review. Over a median follow-up of 7·6 years, a total of 646 ischemic strokes occurred. In a Cox regression model adjusted for socio-demographics, cardiovascular risk factors, and potential confounders, each 10 bpm increase in heart rate was associated with a 10% increase in the risk of ischemic stroke (hazard ratio = 1·10, 95% confidence interval = 1·02, 1·18). In the categorical model, an increased risk of ischemic stroke was observed for heart rates in the middle (hazard ratio = 1·29, 95% confidence interval = 1·06, 1·57) and upper (hazard ratio = 1·37, 95% confidence interval = 1·12, 1·67) tertiles compared with the lower tertile. The results were consistent when the analysis was stratified by age, gender, race, exercise habits, hypertension, and coronary heart disease. In REGARDS, high resting heart rates were associated with an increased risk of ischemic stroke compared with low heart rates. Further research is needed to examine whether interventions aimed to reduce heart rate decrease stroke risk. © 2015 World Stroke Organization.
Pugliese, Chiara; Mazza, Rosa; Andrews, Paul L R; Cerra, Maria C; Fiorito, Graziano; Gattuso, Alfonsina
2016-01-01
Magnesium chloride (MgCl 2 ) is commonly used as a general anesthetic in cephalopods, but its physiological effects including those at cardiac level are not well-characterized. We used an in vitro isolated perfused systemic heart preparation from the common octopus, Octopus vulgaris , to investigate: (a) if in vivo exposure to MgCl 2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery and (b) direct effects of MgCl 2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl 2 in sea water (20 min) or to a mixture of MgCl 2 + ethanol (1.12/1%; 20 min) showed cardiac function (heart rate, stroke volume, cardiac output) comparable to hearts removed from animals killed under hypothermia. However, 3.5% MgCl 2 (1:1, sea water: distilled water, 20 min) produced a significant impairment of the Frank-Starling response as did 45 min exposure to the MgCl 2 + ethanol mixture. Perfusion of the isolated heart with MgCl 2 ± ethanol formulations produced a concentration-related bradycardia (and arrest), a decreased stroke volume and cardiac output indicating a direct effect on the heart. The cardiac effects of MgCl 2 are discussed in relation to the involvement of magnesium, sodium, chloride, and calcium ions, exposure time and osmolality of the formulations and the implications for the use of various formulations of MgCl 2 as anesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl 2 in sea water or to a mixture of MgCl 2 + ethanol is limited to ~20 min, residual effects on cardiac function are unlikely to impact post-anesthetic recovery.
Frea, Simone; Bovolo, Virginia; Bergerone, Serena; D'Ascenzo, Fabrizio; Antolini, Marina; Capriolo, Michele; Canavosio, Federico Giovanni; Morello, Mara; Gaita, Fiorenzo
2012-12-01
Right ventricular (RV) function plays a pivotal role in advanced heart failure patients, especially for screening those who may benefit from left ventricular assist device (LVAD) implantation. We introduce RV contraction pressure index (RVCPI) as a new echo-Doppler parameter of RV function. The accuracy of RVCPI in detecting RV failure was compared with the criterion standard, the RV stroke work index (RVSWI) obtained through right heart catheterization in advanced heart failure patients referred for heart transplantation or LVAD implantation. Right heart catheterization and echo-Doppler were simultaneously performed in 94 consecutive patients referred to our center for advanced heart failure (ejection fraction (EF) 24 ± 8.8%, 40% NYHA functional class IV). RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. Simplified RVCPI (sRVCPI) was derived as TAPSE × (RV - right atrial pressure gradient). Close positive correlation between sRVCPI and RVSWI was found (r = 0.68; P < .001). With logistic regression, we found that increased sRVCPI showed an independent reduced risk (odds ratio 0.98, 95% confidence interval [CI] 0.97-0.99; P = .016) for patients to present a depressed RVSWI (<0.25 mm Hg/L·m(2)). Simplified RVCPI showed high diagnostic accuracy (area under the receiver operating characteristic curve 0.94, 95% CI 0.89-0.99) and good sensitivity and specificity (92% and 85%, respectively) to predict depressed RVSWI with the use of a cutoff value of <400 mm·mm Hg. In patients with advanced heart failure, the new simple bedside sRVCPI closely correlated with RVSWI, providing an independent, noninvasive, and easy tool for the evaluation of RV function. Copyright © 2012 Elsevier Inc. All rights reserved.
Amoozgar, Hamid; Zeighami, Samaneh; Haghpanah, Sezaneh; Karimi, Mehran
2017-01-01
The goal of this study was to compare heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major. In this cross-sectional study, 60 patients with beta thalassemia major and 60 patients with beta thalassemia intermedia who had clinically no symptoms of arrhythmia and clinically normal heart function were evaluated using 24-hour ambulatory electrocardiogram monitoring and echocardiography. For data analysis SPSS ver.20 software was used. A P-value of less than 0.05 was considered statistically significant. The mean age of the beta thalassemia intermedia patients was 24.18 ± 7.9 years and the mean age in beta thalassemia major was 24.38 ± 7.7 years (P>0.05). Premature atrial contractions (PACs) were observed in 14 (23.3%) patients with beta thalassemia intermedia and in 22 (36.6%) beta thalassemia major patients. Premature ventricular contractions (PVCs) were detected in 8 (13.3%) patients in the beta thalassemia intermediate group and 16 (26.6) patients in the beta thalassemia major group, respectively. The left ventricular diastolic dimension, end-diastolic volume, and stroke volume were significantly higher in beta thalassemia intermedia group (P<0.05). Pulmonary acceleration time as an indicator of pulmonary pressure was lower in beta thalassemia intermedia group. Both atrial and ventricular arrhythmias were more common in the beta thalassemia major group. Higher end-diastolic volume and stroke volume were detected in the beta thalassemia intermedia group. Pulmonary acceleration time was lower in the beta thalassemia intermedia group, which can be an indicator of higher pulmonary pressure.
Rinehart, Joseph; Chung, Elena; Canales, Cecilia; Cannesson, Maxime
2012-10-01
The authors compared the performance of a group of anesthesia providers to closed-loop (Learning Intravenous Resuscitator [LIR]) management in a simulated hemorrhage scenario using cardiac output monitoring. A prospective cohort study. In silico simulation. University hospital anesthesiologists and the LIR closed-loop fluid administration system. Using a patient simulator, a 90-minute simulated hemorrhage protocol was run, which included a 1,200-mL blood loss over 30 minutes. Twenty practicing anesthesiology providers were asked to manage this scenario by providing fluids and vasopressor medication at their discretion. The simulation program was also run 20 times with the LIR closed-loop algorithm managing fluids and an additional 20 times with no intervention. Simulated patient weight, height, heart rate, mean arterial pressure, and cardiac output (CO) were similar at baseline. The mean stroke volume, the mean arterial pressure, CO, and the final CO were higher in the closed-loop group than in the practitioners group, and the coefficient of variance was lower. The closed-loop group received slightly more fluid (2.1 v 1.9 L, p < 0.05) than the anesthesiologist group. Despite the roughly similar volumes of fluid given, the closed-loop maintained more stable hemodynamics than the practitioners primarily because the fluid was given earlier in the protocol and CO optimized before the hemorrhage began, whereas practitioners tended to resuscitate well but only after significant hemodynamic change indicated the need. Overall, these data support the potential usefulness of this closed-loop algorithm in clinical settings in which dynamic predictors are not available or applicable. Published by Elsevier Inc.
Gautheron, Vincent; Xie, Yu; Tisserand, Marie; Raoult, Hélène; Soize, Sébastien; Naggara, Olivier; Bourcier, Romain; Richard, Sébastien; Guillemin, Francis; Bracard, Serge; Oppenheim, Catherine
2018-03-01
Stroke patients with large diffusion-weighted imaging (DWI) volumes are often excluded from reperfusion because of reckoned futility. In those with DWI volume >70 mL, included in the THRACE trial (Mechanical Thrombectomy After Intravenous Alteplase Versus Alteplase Alone After Stroke), we report the associations between baseline parameters and outcome. We examined 304 patients with anterior circulation stroke and pretreatment magnetic resonance imaging. Variables were extracted from the THRACE database, and DWI volumes were measured semiautomatically. Among 53 patients with DWI volume >70 mL, 12 had favorable outcome (modified Rankin Scale score, ≤2) at 3 months; they had less coronary disease (0/12 versus 12/38; P =0.046) and less history of smoking (1/10 versus 12/31; P =0.013) than patients with modified Rankin Scale score >2. None of the 8 patients >75 years of age reached modified Rankin Scale score ≤2. Favorable outcome occurred in 12 of 37 M1-occluded patients but in 0 of 16 internal carotid-T/L-occluded patients ( P =0.010). Favorable outcome was more frequent (6/13) when DWI lesion was limited to the superficial middle cerebral artery territory than when it extended to the deep middle cerebral artery territory (6/40; P =0.050). Stroke patients with DWI lesion >70 mL may benefit from reperfusion therapy, especially those with isolated M1 occlusion or ischemia restricted to the superficial middle cerebral artery territory. The benefit of treatment seems questionable for patients with carotid occlusion or lesion extending to the deep middle cerebral artery territory. © 2018 American Heart Association, Inc.
Modeling of Cardiovascular Response to Weightlessness
NASA Technical Reports Server (NTRS)
Sharp, M. Keith
1999-01-01
It was the hypothesis of this Project that the Simple lack of hydrostatic pressure in microgravity generates several purely physical reactions that underlie and may explain, in part, the cardiovascular response to weightlessness. For instance, hydrostatic pressure within the ventricles of the heart may improve cardiac performance by promoting expansion of ventricular volume during diastole. The lack of hydrostatic pressure in microgravity might, therefore, reduce diastolic filling and cardiac performance. The change in transmural pressure is possible due to the difference in hydrostatic pressure gradients between the blood inside the ventricle and the lung tissue surrounding the ventricle due to their different densities. On the other hand, hydrostatic pressure within the vasculature may reduce cardiac inlet pressures because of the typical location of the heart above the hydrostatic indifference level (the level at which pressure remains constant throughout changes in gravity). Additional physical responses of the body to changing gravitational conditions may influence cardiovascular performance. For instance, fluid shifts from the lower body to the thorax in microgravity may serve to increase central venous pressure (CVP) and boost cardiac output (CO). The concurrent release of gravitational force on the rib cage may tend to increase chest girth and decrease pedcardial pressure, augmenting ventricular filling. The lack of gravity on pulmonary tissue may allow an upward shifting of lung mass, causing a further decrease in pericardial pressure and increased CO. Additional effects include diuresis early in the flight, interstitial fluid shifts, gradual spinal extension and movement of abdominal mass, and redistribution of circulatory impedance because of venous distention in the upper body and the collapse of veins in the lower body. In this project, the cardiovascular responses to changes in intraventricular hydrostatic pressure, in intravascular hydrostatic pressure and, to a limited extent, in extravascular and pedcardial hydrostatic pressure were investigated. A complete hydraulic model of the cardiovascular system was built and flown aboard the NASA KC-135 and a computer model was developed and tested in simulated microgravity. Results obtained with these models have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume. When combined with the acute increase in ventricular pressure associated with the elimination of hydrostatic pressure within the vasculature and the resultant cephalad fluid shift with the models in the upright position, however, stroke volume increased in the models. Imposition of a decreased pedcardial pressure in the computer model and in a simplified hydraulic model increased stroke volume. Physiologic regional fluid shifting was also demonstrated by the models. The unifying parameter characterizing of cardiac response was diastolic ventricular transmural pressure (DVDELTAP) The elimination of intraventricular hydrostatic pressure in O-G decreased DVDELTAP stroke volume, while the elimination of intravascular hydrostatic pressure increased DVDELTAP and stroke volume in the upright posture, but reduced DVDELTAP and stroke volume in the launch posture. The release of gravity on the chest wall and its associated influence on intrathoracic pressure, simulated by a drop in extraventricular pressure4, increased DVDELTAP ans stroke volume.
Gregory, T Stan; Oshinski, John; Schmidt, Ehud J; Kwong, Raymond Y; Stevenson, William G; Ho Tse, Zion Tsz
2015-12-01
To develop a technique to noninvasively estimate stroke volume in real time during magnetic resonance imaging (MRI)-guided procedures, based on induced magnetohydrodynamic voltages (VMHD) that occur in ECG recordings during MRI exams, leaving the MRI scanner free to perform other imaging tasks. Because of the relationship between blood flow (BF) and VMHD, we hypothesized that a method to obtain stroke volume could be derived from extracted VMHD vectors in the vectorcardiogram (VCG) frame of reference (VMHDVCG). To estimate a subject-specific BF-VMHD model, VMHDVCG was acquired during a 20-s breath-hold and calibrated versus aortic BF measured using phase-contrast magnetic resonance in 10 subjects (n=10) and 1 subject diagnosed with premature ventricular contractions. Beat-to-beat validation of VMHDVCG-derived BF was performed using real-time phase-contrast imaging in 7 healthy subjects (n=7) during 15-minute cardiac exercise stress tests and 30 minutes after stress relaxation in 3T MRIs. Subject-specific equations were derived to correlate VMHDVCG with BF at rest and validated using real-time phase-contrast. An average error of 7.22% and 3.69% in stroke volume estimation, respectively, was found during peak stress and after complete relaxation. Measured beat-to-beat BF time history derived from real-time phase-contrast and VMHD was highly correlated using a Spearman rank correlation coefficient during stress tests (0.89) and after stress relaxation (0.86). Accurate beat-to-beat stroke volume and BF were estimated using VMHDVCG extracted from intra-MRI 12-lead ECGs, providing a means to enhance patient monitoring during MR imaging and MR-guided interventions. © 2015 American Heart Association, Inc.
... Venous Thromboembolism Aortic Aneurysm More The Heart and Stroke Encyclopedia Click a letter below to get a ... dozens of cardiovascular terms from our Heart and Stroke Encyclopedia and get links to in-depth information. ...
Zhou, Yipeng; Tian, Yunfan; Zhong, Chongke; Batu, Buren; Xu, Tian; Li, Hongmei; Zhang, Mingzhi; Wang, Aili; Zhang, Yonghong
2016-05-01
This study aimed to evaluate the combined effects of family history of cardiovascular diseases (FHCVD) and heart rate on ischemic stroke incidence among Inner Mongolians in China. A prospective cohort study was conducted among 2589 participants aged 20 years and older from Inner Mongolia, China. The participants were divided into four groups according to status of FHCVD and heart rate and followed up from June 2002 to July 2012. Cox proportional hazards models were used to evaluate the combined effects of FHCVD and heart rate on the incidence of ischemic stroke. A total of 76 ischemic stroke occurred during the follow-up period. The observed ischemic stroke cases tended to be older and male, and had higher prevalence of smoking, drinking, hypertension and FHCVD as well as higher systolic and diastolic blood pressures at baseline compared with those who did not experience ischemic stroke. Age- and gender-adjusted hazard ratio (95% confidence interval) of ischemic stroke in the participants with both FHCVD and heart rate ≥ 80 were 2.89 (1.51-5.53), compared with those without FHCVD and heart rate < 80. After multiple adjustment, the association between ischemic stroke risk and both FHCVD and heart rate ≥ 80 remained statistically significant (hazard ratio, 2.47; 95% confidence interval: 1.22-5.01). Our main finding that participants with both FHCVD and faster heart rate have the highest risk of ischemic stroke suggests that faster heart rate may increase the risk of ischemic stroke among people with FHCVD.
Flu and Heart Disease and Stroke
... Seasonal Avian Swine Variant Pandemic Other Flu and Heart Disease & Stroke Language: English (US) Español Recommend on Facebook Tweet Share Compartir People with Heart Disease* and Those Who Have Had a Stroke Are ...
Dekker, A L A J; Phelps, B; Dijkman, B; van der Nagel, T; van der Veen, F H; Geskes, G G; Maessen, J G
2004-06-01
Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.
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.
American Indian and Alaska Native Heart Disease and Stroke
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Xu, Jingyuan; Peng, Xiao; Pan, Chun; Cai, Shixia; Zhang, Xiwen; Xue, Ming; Yang, Yi; Qiu, Haibo
2017-12-01
Significant effort has been devoted to defining parameters for predicting fluid responsiveness. Our goal was to study the feasibility of predicting fluid responsiveness by transcutaneous partial pressure of oxygen (PtcO 2 ) in the critically ill patients. This was a single-center prospective study conducted in the intensive care unit of a tertiary care teaching hospital. Shock patients who presented with at least one clinical sign of inadequate tissue perfusion, defined as systolic blood pressure <90 mmHg or a decrease >40 mmHg in previously hypertensive patients or the need for vasopressive drugs; urine output <0.5 ml/kg/h for 2 h; tachycardia; lactate >4 mmol/l, for less than 24 h in the absence of a contraindication for fluids were eligible to participate in the study. PtcO 2 was continuously recorded before and during a passive leg raising (PLR) test, and then before and after a 250 ml rapid saline infusion in 10 min. Fluid responsiveness is defined as a change in the stroke volume ≥10% after 250 ml of volume infusion. Thirty-four patients were included, and 14 responded to volume expansion. In the responders, the mean arterial pressure, central venous pressure, cardiac output, stroke volume and PtcO 2 increased significantly, while the heart rate decreased significantly by both PLR and volume expansion. Changes in the stroke volume induced either by PLR or volume expansion were significantly greater in responders than in non-responders. The correlation between the changes in PtcO 2 and stroke volume induced by volume expansion was significant. Volume expansion induced an increase in the PtcO 2 of 14% and PLR induced an increase in PtcO 2 of 13% predicted fluid responsiveness. This study suggested the changes in PtcO 2 induced by volume expansion and a PLR test predicted fluid responsiveness in critically ill patients. Trial registration NCT02083757.
Contraction of Blood Clots Is Impaired in Acute Ischemic Stroke.
Tutwiler, Valerie; Peshkova, Alina D; Andrianova, Izabella A; Khasanova, Dina R; Weisel, John W; Litvinov, Rustem I
2017-02-01
Obstructive thrombi or thrombotic emboli are the pathogenic basis of ischemic stroke. In vitro blood clots and in vivo thrombi can undergo platelet-driven contraction (retraction), resulting in volume shrinkage. Clot contraction can potentially reduce vessel occlusion and improve blood flow past emboli or thrombi. The aim of this work was to examine a potential pathogenic role of clot contraction in ischemic stroke. We used a novel automated method that enabled us to quantify time of initiation and extent and rate of clot contraction in vitro. The main finding is that clot contraction from the blood of stroke patients was reduced compared with healthy subjects. Reduced clot contraction correlated with a lower platelet count and their dysfunction, higher levels of fibrinogen and hematocrit, leukocytosis, and other changes in blood composition that may affect platelet function and properties of blood clots. Platelets from stroke patents were spontaneously activated and displayed reduced responsiveness to additional stimulation. Clinical correlations with respect to severity and stroke pathogenesis suggest that the impaired clot contraction has the potential to be a pathogenic factor in ischemic stroke. The changeable ability of clots and thrombi to shrink in volume may be a novel unappreciated mechanism that aggravates or alleviates the course and outcomes of ischemic stroke. The clinical importance of clot or thrombus transformations in vivo and the diagnostic and prognostic value of this blood test for clot contraction need further exploration. © 2016 American Heart Association, Inc.
Ventricular efficiency in pregnant women with congenital heart disease.
Muneuchi, Jun; Yamasaki, Keiko; Watanabe, Mamie; Fukumitsu, Azusa; Kawakami, Takeshi; Nakahara, Hiromasa; Joo, Kunitaka
2018-06-15
Pregnant women with congenital heart disease (CHD) are at risk of cardiovascular events during pregnancy as well as postpartum. The aim of our study is to address the feasibility of echocardiography-derived ventricular-arterial coupling during pregnancy and postpartum among women with CHD. In 31 pregnant women with CHD, we performed serial echocardiography at the first and third trimesters, early and late postpartum. The indices of contractility (single-beat determined end-systolic elastance, Ees ab ) and afterload (effective arterial elastance, Ea) were approximated on the basis of the systemic blood pressure and systemic ventricular volume. The ratio of stroke work and pressure-volume area (SW/PVA) representing ventricular efficiency was also calculated. Age at the delivery was 28 (24-31) years. ZAHARA score was 0.75 (0.75-1.50). Gestational age and birth weight of newborns were 38 (37-39) weeks and 2.73 (2.42-2.92) kg, respectively. Heart rate, systemic ventricular end-diastolic volume and stroke volume significantly increased from the first trimester to the third trimester and reversed postpartum to the values of the first trimester. Ees ab and Ea significantly decreased from the first trimester to the third trimester (Ees ab ; 4.90 [2.86-7.14] vs 3.41 [2.53-4.61] mm Hg/ml, p = 0.0001, Ea; 2.83 [1.74-3.30] vs 2.18 [1.67-2.68] mm Hg/ml, p = 0.0012), and reversed early postpartum parallelly. Ejection fraction and SW/PVA remained unchanged throughout pregnancy and postpartum. Echocardiography-derived ventricular-arterial coupling is feasible to understand ventricular function in pregnant women with CHD. Copyright © 2018 Elsevier B.V. All rights reserved.
Cardiac changes induced by immersion and breath-hold diving in humans.
Marabotti, Claudio; Scalzini, Alessandro; Cialoni, Danilo; Passera, Mirko; L'Abbate, Antonio; Bedini, Remo
2009-01-01
To evaluate the separate cardiovascular response to body immersion and increased environmental pressure during diving, 12 healthy male subjects (mean age 35.2 +/- 6.5 yr) underwent two-dimensional Doppler echocardiography in five different conditions: out of water (basal); head-out immersion while breathing (condition A); fully immersed at the surface while breathing (condition B) and breath holding (condition C); and breath-hold diving at 5-m depth (condition D). Heart rate, left ventricular volumes, stroke volume, and cardiac output were obtained by underwater echocardiography. Early (E) and late (A) transmitral flow velocities, their ratio (E/A), and deceleration time of E (DTE) were also obtained from pulsed-wave Doppler, as left ventricular diastolic function indexes. The experimental protocol induced significant reductions in left ventricular volumes, left ventricular stroke volume (P < 0.05), cardiac output (P < 0.001), and heart rate (P < 0.05). A significant increase in E peak (P < 0.01) and E/A (P < 0.01) and a significant reduction of DTE (P < 0.01) were also observed. Changes occurring during diving (condition D) accounted for most of the changes observed in the experimental series. In particular, cardiac output at condition D was significantly lower compared with each of the other experimental conditions, E/A was significantly higher during condition D than in conditions A and C. Finally, DTE was significantly shorter at condition D than in basal and condition C. This study confirms a reduction of cardiac output in diving humans. Since most of the changes were observed during diving, the increased environmental pressure seems responsible for this hemodynamic rearrangement. Left ventricular diastolic function changes suggest a constrictive effect on the heart, possibly accounting for cardiac output reduction.
Etherton, Mark R; Wu, Ona; Cougo, Pedro; Giese, Anne-Katrin; Cloonan, Lisa; Fitzpatrick, Kaitlin M; Kanakis, Allison S; Boulouis, Gregoire; Karadeli, Hasan H; Lauer, Arne; Rosand, Jonathan; Furie, Karen L; Rost, Natalia S
2017-12-01
Women have worse poststroke outcomes than men. We evaluated sex-specific clinical and neuroimaging characteristics of white matter in association with functional recovery after acute ischemic stroke. We performed a retrospective analysis of acute ischemic stroke patients with admission brain MRI and 3- to 6-month modified Rankin Scale score. White matter hyperintensity and acute infarct volume were quantified on fluid-attenuated inversion recovery and diffusion tensor imaging MRI, respectively. Diffusivity anisotropy metrics were calculated in normal appearing white matter contralateral to the acute ischemia. Among 319 patients with acute ischemic stroke, women were older (68.0 versus 62.7 years; P =0.004), had increased incidence of atrial fibrillation (21.4% versus 12.2%; P =0.04), and lower rate of tobacco use (21.1% versus 35.9%; P =0.03). There was no sex-specific difference in white matter hyperintensity volume, acute infarct volume, National Institutes of Health Stroke Scale, prestroke modified Rankin Scale score, or normal appearing white matter diffusivity anisotropy metrics. However, women were less likely to have an excellent outcome (modified Rankin Scale score <2: 49.6% versus 67.0%; P =0.005). In logistic regression analysis, female sex and the interaction of sex with fractional anisotropy, radial diffusivity, and axial diffusivity were independent predictors of functional outcome. Female sex is associated with decreased likelihood of excellent outcome after acute ischemic stroke. The correlation between markers of white matter integrity and functional outcomes in women, but not men, suggests a potential sex-specific mechanism. © 2017 American Heart Association, Inc.
Fussman, Chris; Rafferty, Ann P; Reeves, Mathew J; Zackery, Shannon; Lyon-Callo, Sarah; Anderson, Beth
2009-01-01
To describe the level of knowledge regarding risk factors and warning signs for stroke and heart attack among White and African American adults in Michigan and to quantify racial disparities. Knowledge of stroke and heart attack risk factors and warning signs was assessed by using data from the 2004 Michigan Behavioral Risk Factor Survey. Prevalence estimates of knowledge were generated, and statistical differences in knowledge between Whites and African Americans were assessed. Adequate knowledge was defined as knowing 3 correct warning signs or risk factors. Logistic regression models were used to quantify the racial disparity in knowledge while controlling for potential confounding. Whites had substantially higher levels of adequate knowledge of risk factors (stroke: 31.6% vs 13.8%; heart attack: 52.6% vs 24.3%) and warning signs (stroke: 30.0% vs 17.2%; heart attack: 29.3% vs 13.8%) compared with African Americans (all observed differences were significant at P < .05). The odds of adequate knowledge of risk factors (stroke: adjusted odds ratio [AOR] 2.9; heart attack: AOR 3.4) and warning signs (stroke: AOR 2.0; heart attack: AOR 2.4) were significantly higher for Whites than for African Americans. A strong racial disparity in the knowledge of stroke and heart attack risk factors and warning signs exists among Michigan adults. Communitywide public education programs in conjunction with targeted interventions for at-risk populations are necessary to produce meaningful improvements in the awareness of stroke and heart attack risk factors and warning signs among Michigan adults.
Middle cerebral artery occlusion in Macaca fascicularis: acute and chronic stroke evolution.
D'Arceuil, Helen E; Duggan, Michael; He, Julian; Pryor, Johnny; de Crespigny, Alex
2006-04-01
An intravascular stroke model designed for magnetic resonance imaging was developed in Macaca fascicularis (M. fascicularis) to characterize serial stroke lesion evolution. This model produces a range of stroke lesion sizes which closely mimics human stroke evolution. This paper describes the care of animals undergoing this stroke procedure, the range of outcomes we experienced and the cause of mortality in this model. Anesthesia was induced with atropine and ketamine and maintained with isoflurane or propofol. Non-invasive blood pressure, oxygen saturation, heart rate, respiration rate, temperature and end tidal CO2 were monitored continuously. The stroke was created by occluding a distal branch of the middle cerebral artery. During catheter placement animals were heparinized and vasospasm was minimized using verapamil. Anesthetic induction and maintenance were smooth. Animals with small strokes showed very rapid recovery, were able to ambulate and self-feed within 2 hours of recovery. Animals with strokes of >or=4% of the hemispheric volume required lengthy observation during recovery and parenteral nutrition. Large strokes resulted in significant brain edema, herniation and brainstem compression. Intracerebral hemorrhage and or subarachnoid hemorrhage coupled with a stroke of any size was acutely fatal. In the absence of an effective acute stroke therapy, the spectrum of outcomes seen in our primate model is very similar to that observed in human stroke patients.
Shams, Tanzila; Zaidat, Osama; Yavagal, Dileep; Xavier, Andrew; Jovin, Tudor; Janardhan, Vallabh
2016-01-01
Brain attack care is rapidly evolving with cutting-edge stroke interventions similar to the growth of heart attack care with cardiac interventions in the last two decades. As the field of stroke intervention is growing exponentially globally, there is clearly an unmet need to standardize stroke interventional laboratories for safe, effective, and timely stroke care. Towards this goal, the Society of Vascular and Interventional Neurology (SVIN) Writing Committee has developed the Stroke Interventional Laboratory Consensus (SILC) criteria using a 7M management approach for the development and standardization of each stroke interventional laboratory within stroke centers. The SILC criteria include: (1) manpower: personnel including roles of medical and administrative directors, attending physicians, fellows, physician extenders, and all the key stakeholders in the stroke chain of survival; (2) machines: resources needed in terms of physical facilities, and angiography equipment; (3) materials: medical device inventory, medications, and angiography supplies; (4) methods: standardized protocols for stroke workflow optimization; (5) metrics (volume): existing credentialing criteria for facilities and stroke interventionalists; (6) metrics (quality): benchmarks for quality assurance; (7) metrics (safety): radiation and procedural safety practices. PMID:27610118
Powers, William J; Derdeyn, Colin P; Biller, José; Coffey, Christopher S; Hoh, Brian L; Jauch, Edward C; Johnston, Karen C; Johnston, S Claiborne; Khalessi, Alexander A; Kidwell, Chelsea S; Meschia, James F; Ovbiagele, Bruce; Yavagal, Dileep R
2015-10-01
The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines. This focused update analyzes results from 8 randomized, clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed by the American Heart Association/American Stroke Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association/American Stroke Association Manuscript Oversight Committee. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statement Oversight Committee and Stroke Council Leadership Committee. Evidence-based guidelines are presented for the selection of patients with acute ischemic stroke for endovascular treatment, for the endovascular procedure, and for systems of care to facilitate endovascular treatment. Certain endovascular procedures have been demonstrated to provide clinical benefit in selected patients with acute ischemic stroke. Systems of care should be organized to facilitate the delivery of this care. © 2015 American Heart Association, Inc.
Nikitin, A S; Abzalov, R A; Abzalov, N I; Vafina, E Z
2013-08-01
The indicators of heart pumping ability of rats at a muscular loading of the maximum power and also in the conditions of transition from sharply strengthened motor activity regime on a strengthened motor activity regime at adrenergic influence stimulation and blockade were investigated. At rats of 100-daily age at the strengthened motor activity heart rate is less, and blood stroke volume is more, than in the rats, subject to muscular loading of the maximum power. The adrenergic influence on the heart's pumping ability of sharply strengthened motor activity rats is much more, than of unlimited motor activity rats. At the α1-adrenoreceptors blockade at 100-daily rats the decreasing in intensity of muscular loading causes increased in adrenergic influence on heart pumping ability.
Zheng, Hong; Guo, Hai; Ye, Jian-rong; Chen, Lin
2012-06-01
To develop and evaluate an individualized fluid therapy in the elderly patients with coronary heart disease undergoing gastrointestinal surgery. In this prospective study, 60 coronary heart disease patients undergoing gastrointestinal surgery were included in the First Affiliated Hospital of Xinjiang Medical University from March 2009 to March 2012. Patients were randomized into the intervention group and the control group with 30 patients in each group. Individualized fluid therapy was used during surgery and postoperative period in the ICU, which was determined based on target controlled fluid therapy according to cardiac index, stroke volume, and stroke volume variation. Traditional fluid therapy was used in the control group in the intraoperative and postoperative period. The two groups were compared in terms of postoperative hemodynamic parameters, total fluid volume, incidence of adverse cardiac events, and recovery of bowel function. Compared with the control group, mean arterial pressure was significantly increased at the commencement of the surgery. The cardiac index was significantly elevated during surgery and at the end of the surgery. Stroke volume was significantly increased after induction of anesthesia, during the surgery, and at the early stay of ICU period(all P<0.05). Serum lactic acid in the intervention group was significantly lower at the end of surgery and during ICU stay than that in the control group (all P<0.05). During surgery and 24-hour stay in ICU, the total fluid volume, crystal usage, and urine were significantly less, while colloidal fluid use was significantly more in the intervention group as compared to the control group(all P<0.05). The perioperative adverse cardiac event rate was 36.7%(11/30) in the intervention group, lower than 56.7%(17/30) in the control group, but the difference was no statistically significance(P>0.05). In the intervention group, defecation time, time to first flatus, resumption of liquid intake, length of ICU stay and hospital stay were significantly less compared with the control group(P<0.05). In the elderly patients with coronary arterial disease undergoing gastrointestinal surgery, individualized fluid therapy can effectively decrease adverse cardiac events, improve postoperative gastrointestinal function, and reduce length of hospital stay.
Schiller, Petter; Vikholm, Per; Hellgren, Laila
2016-03-01
Right ventricular (RV) failure is a major cause of morbidity and mortality after left ventricular assist device (LVAD) placement and remains hard to predict. We hypothesized that partial surgical exclusion of the RV with a modified Glenn shunt during LVAD treatment would reduce RV stroke work. An LVAD was implanted in eight pigs and a modified Glenn shunt was constructed. A conductance pressure-volume catheter was placed in the right ventricle through the apex. Haemodynamic data and pressure-volume loops were obtained at the following time periods: (i) baseline, (ii) open shunt, (iii) LVAD with closed shunt and (iii) LVAD and open shunt. During LVAD therapy, the right atrial (RA) pressure increased from 9 mmHg (9-9) to 15 mmHg (12-15), P = 0.01. RV stroke volume increased from 30 ml (29-40) to 51 ml (42-53), P < 0.01. Also, RV stroke work increased to 708 mmHg ml (654-1193) from 535 mmHg ml (424-717), P = 0.04, compared with baseline. During LVAD therapy in combination with a Glenn shunt, the RA pressure decreased from 15 mmHg (12-15) to 10 mmHg (7-11) when compared with LVAD therapy only, P = 0.01. A decrease in RV stroke work from 708 mmHg ml (654-1193) to 465 mmHg ml (366-711), P = 0.04, was seen when the LVAD was combined with a shunt, not significantly different from the baseline value (535 mmHg ml). The developed pressure in the right ventricle decreased from 29 mmHg (26-32) to 21 mmHg (20-24), P < 0.01. The pressure-volume loops of the RV show a significant reduction of RV stroke work during the use of the shunt with LVAD treatment. A modified Glenn shunt reduced RV volumes, RV stroke work and RA pressure during LVAD therapy in an experimental model of heart failure in pigs. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
Ischemic stroke due to embolic heart diseases and associated factors in Benin hospital setting.
Gnonlonfoun, Dieudonné; Adjien, Constant; Gnimavo, Ronald; Goudjinou, Gérard; Hotcho, Corine; Nyangui Mapaga, Jennifer; Sowanou, Arlos; Gnigone, Pupchen; Domingo, Rodrigue; Houinato, Dismand
2018-04-15
Poor access to cardiovascular checkups is a major cause of ignorance of embolic heart diseases as the etiology for ischemic stroke. Study ischemic strokes due to embolic heart diseases and their associated factors. It was a cross-sectional, prospective, descriptive and analytical study conducted from November 1, 2014 to August 31, 2015 on 104 patients with ischemic stroke confirmed through brain imaging. Embolic heart diseases included arrhythmia due to atrial fibrillation (AF), atrial flutter, myocardial infarction (MI), heart valve diseases and atrial septal aneurysm (ASA). The dependent variable was embolic heart disease while independent variables encompassed socio-demographic factors, patients' history, and lifestyle. Data analysis was carried out through SAS 9.3. The rate of embolic heart diseases (EHD) as etiology for ischemic stroke was 26% (28/104). AF accounted for 69% of embolic heart diseases and 22.8% of etiologies for ischemic stroke. Ischemic strokes prevalence was 3.5%, 2.5% and 1.2% respectively for heart valve diseases, MI and ASA. The associated factor was age (p=0.000). The diagnosis of a potential cardiac source of embolism is essential because of therapeutic and prognostic implications. Wherefore, there is need for cardiovascular examination particularly Holter ECG and cardiac ultrasound examination which are not always accessible to our populations. Copyright © 2018 Elsevier B.V. All rights reserved.
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Can You Recognize a Heart Attack or Stroke? What To Do When Every Moment Counts
... 2014 Print this issue Can You Recognize a Heart Attack or Stroke? What To Do When Every Moment ... When it comes to life-threatening conditions like heart attack or stroke, every minute counts. Get to know ...
Effect of hypokinesia on cardiac contractile function and nervous regulation of the heart
NASA Technical Reports Server (NTRS)
Meyerson, F. Z.; Kapelko, V. I.; Gorina, M. S.; Shchegolkov, A. N.; Larinov, N. P.
1980-01-01
Longterm hypokinesia caused cardiac deadaptation in rabbits, which resulted in the diminishing of the left ventricular rate of contraction and relaxation, joined later by decreased vascular resistance. As a results, the ejection rate as well as stroke volume and cardiac output were normal. The decrease of the relaxation speed was more obvious at a high heart rate and results in shortening of the diastolic pause and diminishing of cardiac output. Hearts of the hypokinetic animals were characterized by normal maximal pressure developed by a unit of muccardial mass aorta clamping, decreased adrenoreactivity, and increased cholinoreactivity. This complex of changes is contrary to changes observed in adaptation to exercise, but is similar to changes observed in compensatory hypertrophy of the heart.
Lutfiyya, May Nawal; Cumba, Marites T; McCullough, Joel Emery; Barlow, Erika Laverne; Lipsky, Martin S
2008-06-01
Heart disease and stroke are the first and third leading causes of death of American women, respectively. African American women experience a disproportionate burden of these diseases compared with Caucasian women and are also more likely to delay seeking treatment for acute symptoms. As knowledge is a first step in seeking care, this study examined the knowledge of heart attack and stroke symptoms among African American women. This was a cross-sectional study analyzing 2003-2005 Behavioral Risk Factor Surveillance Survey (BRFSS) data. A composite heart attack and stroke knowledge score was computed for each respondent from the 13 heart attack and stroke symptom knowledge questions. Multivariate logistic regression was performed using low scores on the heart attack and stroke knowledge questions as the dependent variable. Twenty percent of the respondents were low scorers, and 23.8% were high scorers. Logistic regression analysis showed that adult African American women who earned low scores on the composite heart attack and stroke knowledge questions (range 0-8 points) were more likely to be aged 18-34 (OR = 1.36, CI 1.35, 1.37), be uninsured (OR = 1.32, CI 1.31, 1.33), have an annual household income <$35,000 (OR = 1.46, CI 1.45, 1.47), and have a primary healthcare provider (OR = 1.22, CI 1.20, 1.23). The findings indicated that knowledge of heart attack and stroke symptoms varied significantly among African American women, depending on socioeconomic variables. Targeting interventions to African American women, particularly those in lower socioeconomic groups, may increase knowledge of heart attack and stroke symptoms, subsequently improving preventive action taken in response to these conditions.
Bickel, Amitai; Shturman, Alexander; Sergeiev, Michael; Ivry, Shimon; Eitan, Arieh; Atar, Shaul
2014-10-01
Pneumatic leg sleeves are widely used after prolonged operations for prevention of venous stasis. In healthy volunteers they increase cardiac function. We evaluated the hemodynamic effects and safety of intermittent sequential pneumatic compression (ISPC) leg sleeves in patients with chronic congestive heart failure (CHF). We studied 19 patients with systolic left ventricular dysfunction and CHF. ISPC leg sleeves, each with 10 air cells, were operated by a computerized compressor, exerting 2 cycles/min. Hemodynamic and echocardiographic parameters were measured before, during, and after ISPC activation. The baseline mean left ventricular ejection fraction was 29 ± 9.2%, median 32%, range 10%-40%. Cardiac output (from 4.26 to 4.83 L/min; P = .008) and stroke volume (from 56.1 to 63.5 mL; P = .029) increased significantly after ISPC activation, without a reciprocal increase in heart rate, and declined after sleeve deactivation. Systemic vascular resistance (SVR) decreased significantly (from 1,520 to 1,216 dyne-s/cm5; P = .0005), and remained lower than the baseline level throughout the study. There was no detrimental effect on diastolic function and no adverse clinical events, despite increased pulmonary venous return. ISPC leg sleeves in patients with chronic CHF do not exacerbate symptoms and transiently improve cardiac output through an increase in stroke volume and a reduction in SVR. Copyright © 2014 Elsevier Inc. All rights reserved.
Compliant Buckled Foam Actuators and Application in Patient-Specific Direct Cardiac Compression.
Mac Murray, Benjamin C; Futran, Chaim C; Lee, Jeanne; O'Brien, Kevin W; Amiri Moghadam, Amir A; Mosadegh, Bobak; Silberstein, Meredith N; Min, James K; Shepherd, Robert F
2018-02-01
We introduce the use of buckled foam for soft pneumatic actuators. A moderate amount of residual compressive strain within elastomer foam increases the applied force ∼1.4 × or stroke ∼2 × compared with actuators without residual strain. The origin of these improved characteristics is explained analytically. These actuators are applied in a direct cardiac compression (DCC) device design, a type of implanted mechanical circulatory support that avoids direct blood contact, mitigating risks of clot formation and stroke. This article describes a first step toward a pneumatically powered, patient-specific DCC design by employing elastomer foam as the mechanism for cardiac compression. To form the device, a mold of a patient's heart was obtained by 3D printing a digitized X-ray computed tomography or magnetic resonance imaging scan into a solid model. From this model, a soft, robotic foam DCC device was molded. The DCC device is compliant and uses compressed air to inflate foam chambers that in turn apply compression to the exterior of a heart. The device is demonstrated on a porcine heart and is capable of assisting heart pumping at physiologically relevant durations (∼200 ms for systole and ∼400 ms for diastole) and stroke volumes (∼70 mL). Although further development is necessary to produce a fully implantable device, the material and processing insights presented here are essential to the implementation of a foam-based, patient-specific DCC design.
Vaillant, Fanny; Lauzier, Benjamin; Ruiz, Matthieu; Shi, Yanfen; Lachance, Dominic; Rivard, Marie-Eve; Bolduc, Virginie; Thorin, Eric; Tardif, Jean-Claude; Des Rosiers, Christine
2016-10-01
While heart rate reduction (HRR) is a target for the management of patients with heart disease, contradictory results were reported using ivabradine, which selectively inhibits the pacemaker I f current, vs. β-blockers like metoprolol. This study aimed at testing whether similar HRR with ivabradine vs. metoprolol differentially modulates cardiac energy substrate metabolism, a factor determinant for cardiac function, in a mouse model of dyslipidemia (hApoB +/+ ;LDLR -/- ). Following a longitudinal study design, we used 3- and 6-mo-old mice, untreated or treated for 3 mo with ivabradine or metoprolol. Cardiac function was evaluated in vivo and ex vivo in working hearts perfused with 13 C-labeled substrates to assess substrate fluxes through energy metabolic pathways. Compared with 3-mo-old, 6-mo-old dyslipidemic mice had similar cardiac hemodynamics in vivo but impaired (P < 0.001) contractile function (aortic flow: -45%; cardiac output: -34%; stroke volume: -35%) and glycolysis (-24%) ex vivo. Despite inducing a similar 10% HRR, ivabradine-treated hearts displayed significantly higher stroke volume values and glycolysis vs. their metoprolol-treated counterparts ex vivo, values for the ivabradine group being often not significantly different from 3-mo-old mice. Further analyses highlighted additional significant cardiac alterations with disease progression, namely in the total tissue level of proteins modified by O-linked N-acetylglucosamine (O-GlcNAc), whose formation is governed by glucose metabolism via the hexosamine biosynthetic pathway, which showed a similar pattern with ivabradine vs. metoprolol treatment. Collectively, our results emphasize the implication of alterations in cardiac glucose metabolism and signaling linked to disease progression in our mouse model. Despite similar HRR, ivabradine, but not metoprolol, preserved cardiac function and glucose metabolism during disease progression. Copyright © 2016 the American Physiological Society.
NASA Technical Reports Server (NTRS)
Evans, J. M.; Ziegler, M. G.; Patwardhan, A. R.; Ott, J. B.; Kim, C. S.; Leonelli, F. M.; Knapp, C. F.
2001-01-01
The autonomic nervous system drives variability in heart rate, vascular tone, cardiac ejection, and arterial pressure, but gender differences in autonomic regulation of the latter three parameters are not well documented. In addition to mean values, we used spectral analysis to calculate variability in arterial pressure, heart rate (R-R interval, RRI), stroke volume, and total peripheral resistance (TPR) and measured circulating levels of catecholamines and pancreatic polypeptide in two groups of 25 +/- 1.2-yr-old, healthy men and healthy follicular-phase women (40 total subjects, 10 men and 10 women per group). Group 1 subjects were studied supine, before and after beta- and muscarinic autonomic blockades, administered singly and together on separate days of study. Group 2 subjects were studied supine and drug free with the additional measurement of skin perfusion. In the unblocked state, we found that circulating levels of epinephrine and total spectral power of stroke volume, TPR, and skin perfusion ranged from two to six times greater in men than in women. The difference (men > women) in spectral power of TPR was maintained after beta- and muscarinic blockades, suggesting that the greater oscillations of vascular resistance in men may be alpha-adrenergically mediated. Men exhibited muscarinic buffering of mean TPR whereas women exhibited beta-adrenergic buffering of mean TPR as well as TPR and heart rate oscillations. Women had a greater distribution of RRI power in the breathing frequency range and a less negative slope of ln RRI power vs. ln frequency, both indicators that parasympathetic stimuli were the dominant influence on women's heart rate variability. The results of our study suggest a predominance of sympathetic vascular regulation in men compared with a dominant parasympathetic influence on heart rate regulation in women.
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Hsiao, Shih-Hung; Lin, Shih-Kai; Chiou, Yi-Ran; Cheng, Chin-Chang; Hwang, Hwong-Ru; Chiou, Kuan-Rau
2018-06-01
Titration of evidence-based medications, important for treating heart failure (HF), is often underdosed by symptom-guided treatment. The aim of this study was to investigate, using echocardiographic parameters, stroke volume and left ventricular (LV) filling pressure to guide up-titration of medications, increasing prognostic benefits. A total of 765 patients with chronic HF and severely reduced LV ejection fractions (<35%), referred from 2008 to 2016, were prospectively studied. Echocardiographic guidance was performed in 149 patients. LV filling pressure was assessed by left atrial expansion index, and stroke volume was estimated from diameter and time-velocity integral in the LV outflow tract. Up-titration of evidence-based medications and adjustment for side effects or worsening clinical conditions according to those parameters were performed. Propensity score matching was used to match pairs of patients with (n = 110) or without (n = 110) echocardiographic guidance. End points were 4-year frequencies of HF hospitalization and all-cause mortality. During a mean follow-up time of 4.1 years, rates of adverse events were 58 (52.7%) with no echocardiographic guidance and 36 (32.7%) with echocardiographic guidance (P < .0001). Echocardiography provided effective guidance to reduce prescribing frequency and dose of diuretics and to promote evidence-based medication prescription. It reduced HF rehospitalization and all-cause mortality. By multivariate analysis, prognostic improvement was associated with up-titration of medications with echocardiographic guidance. There was a statistically significant difference in long-term prognosis between propensity score-matched pairs of patients with chronic severe HF with and without echocardiographic guidance. These findings need further validation in large prospective clinical trials. Copyright © 2018 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.
Zhang, Jian; Chen, Chao Qin; Lei, Xiu Zhen; Feng, Zhi Ying; Zhu, Sheng Mei
2013-07-01
This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting) in thoracic surgery patients requiring one-lung ventilation.
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Modeling static and dynamic human cardiovascular responses to exercise.
Stremel, R W; Bernauer, E M; Harter, L W; Schultz, R A; Walters, R F
1975-08-01
A human performance model has been developed and described [9] which portrays the human circulatory, thermo regulatory and energy-exchange systems as an intercoupled set. In this model, steady state or static relationships are used to describe oxygen consumption and blood flow. For example, heart rate (HTRT) is calculated as a function of the oxygen and the thermo-regulatory requirements of each body compartment, using the steady state work values of cardiac output (CO, sum of all compartment blood flows) and stroke volume (SV, assumed maximal after 40% maximal oxygen consumption): HTRT=CO/SV. The steady state model has proven to be an acceptable first approximation, but the inclusion of transient characteristics are essential in describing the overall systems' adjustment to exercise stress. In the present study, the dynamic transient characteristics of heart rate, stroke volume and cardiac output were obtained from experiments utilizing step and sinusoidal forcing of work. The gain and phase relationships reveal a probable first order system with a six minute time constant, and are utilized to model the transient characteristics of these parameters. This approach leads to a more complex model but a more accurate representation of the physiology involved. The instrumentation and programming essential to these experiments are described.
Knowledge of signs and symptoms of heart attack and stroke among Singapore residents.
Quah, Joy Li Juan; Yap, Susan; Cheah, Si Oon; Ng, Yih Yng; Goh, E Shaun; Doctor, Nausheen; Leong, Benjamin Sieu-Hon; Tiah, Ling; Chia, Michael Yih Chong; Ong, Marcus Eng Hock
2014-01-01
To determine the level of knowledge of signs and symptoms of heart attack and stroke in Singapore resident population, in comparison to the global community. A population based, random sample of 7,840 household addresses was selected from a validated national sampling frame. Each participant was asked eight questions on signs and symptoms of heart attack and 10 questions on stroke. The response rate was 65.2% with 4,192 respondents. The level of knowledge for preselected, common signs and symptoms of heart attack and stroke was 57.8% and 57.1%, respectively. The respondents scored a mean of 5.0 (SD 2.4) out of 8 for heart attack, while they scored a mean of 6.8 (SD 2.9) out of 10 for stroke. Respondents who were ≥ 50 years, with lower educational level, and unemployed/retired had the least knowledge about both conditions. The level of knowledge of signs and symptoms of heart attack and stroke in Singapore is comparable to USA and Canada. We found a comparable knowledge of stroke and heart attack signs and symptoms in the community to countries within the same economic, educational, and healthcare strata. However older persons, those with lower educational level and those who are unemployed/retired, require more public health education efforts.
Wenk, Jonathan F; Wall, Samuel T; Peterson, Robert C; Helgerson, Sam L; Sabbah, Hani N; Burger, Mike; Stander, Nielen; Ratcliffe, Mark B; Guccione, Julius M
2009-12-01
Heart failure continues to present a significant medical and economic burden throughout the developed world. Novel treatments involving the injection of polymeric materials into the myocardium of the failing left ventricle (LV) are currently being developed, which may reduce elevated myofiber stresses during the cardiac cycle and act to retard the progression of heart failure. A finite element (FE) simulation-based method was developed in this study that can automatically optimize the injection pattern of the polymeric "inclusions" according to a specific objective function, using commercially available software tools. The FE preprocessor TRUEGRID((R)) was used to create a parametric axisymmetric LV mesh matched to experimentally measured end-diastole and end-systole metrics from dogs with coronary microembolization-induced heart failure. Passive and active myocardial material properties were defined by a pseudo-elastic-strain energy function and a time-varying elastance model of active contraction, respectively, that were implemented in the FE software LS-DYNA. The companion optimization software LS-OPT was used to communicate directly with TRUEGRID((R)) to determine FE model parameters, such as defining the injection pattern and inclusion characteristics. The optimization resulted in an intuitive optimal injection pattern (i.e., the one with the greatest number of inclusions) when the objective function was weighted to minimize mean end-diastolic and end-systolic myofiber stress and ignore LV stroke volume. In contrast, the optimization resulted in a nonintuitive optimal pattern (i.e., 3 inclusions longitudinallyx6 inclusions circumferentially) when both myofiber stress and stroke volume were incorporated into the objective function with different weights.
Zakeri, Rosita; Moulay, Gilles; Chai, Qiang; Ogut, Ozgur; Hussain, Saad; Takahama, Hiroyuki; Lu, Tong; Wang, Xiao-Li; Linke, Wolfgang A.; Lee, Hon-Chi; Redfield, Margaret M.
2016-01-01
Background Left atrial (LA) compliance and contractility influence left ventricular (LV) stroke volume. We hypothesized that diminished LA compliance and contractile function occur early during development of heart failure with preserved ejection fraction (HFpEF) and impair overall cardiac performance. Method and Results Cardiac magnetic resonance imaging, echocardiography, LV and LA pressure-volume studies, and tissue analyses were performed in a model of early HFpEF (elderly dogs, renal wrap-induced hypertension, exogenous aldosterone; n=9) and young control dogs (sham surgery; n=13). Early HFpEF was associated with LA enlargement, cardiomyocyte hypertrophy and enhanced LA contractile function (median active emptying fraction 16% [95% CI 13–24] vs 12[10–14]%, p=0.008; end-systolic pressure-volume relationship slope 2.4[1.9–3.2]mmHg/mL HFpEF vs 1.5[1.2–2.2]mmHg/mL controls, p=0.01). However, atrioventricular coupling was impaired and the curvilinear LA end-reservoir pressure-volume relationship was shifted upward/leftward in HFpEF (LA stiffness constant, βLA, 0.16[0.11–0.18]mmHg/mL vs 0.06[0.04–0.10]mmHg/mL controls, p=0.002) indicating reduced LA compliance. Impaired atrioventricular coupling and lower LA compliance correlated with lower LV stroke volume. Total fibrosis and titin isoform composition were similar between groups, however titin was hyperphosphorylated in HFpEF and correlated with βLA. LA microvascular reactivity was diminished in HFpEF versus controls. LA microvascular density tended to be lower in HFpEF and inversely correlated with βLA. Conclusions In early-stage hypertensive HFpEF, LA cardiomyocyte hypertrophy, titin hyperphosphorylation and microvascular dysfunction occur in association with increased systolic and diastolic LA chamber stiffness, impaired atrioventricular coupling and decreased LV stroke volume. These data indicate that maladaptive LA remodeling occurs early during HFpEF development, supporting a concept of global myocardial remodeling. PMID:27758811
Unique strain history during ejection in canine left ventricle.
Douglas, A S; Rodriguez, E K; O'Dell, W; Hunter, W C
1991-05-01
Understanding the relationship between structure and function in the heart requires a knowledge of the connection between the local behavior of the myocardium (e.g., shortening) and the pumping action of the left ventricle. We asked the question, how do changes in preload and afterload affect the relationship between local myocardial deformation and ventricular volume? To study this, a set of small radiopaque beads was implanted in approximately 1 cm3 of the isolated canine heart left ventricular free wall. Using biplane cineradiography, we tracked the motion of these markers through various cardiac cycles (controlling pre- and afterload) using the relative motion of six markers to quantify the local three dimensional Lagrangian strain. Two different reference states (used to define the strains) were considered. First, we used the configuration of the heart at end diastole for that particular cardiac cycle to define the individual strains (which gave the local "shortening fraction") and the ejection fraction. Second, we used a single reference state for all cardiac cycles i.e., the end-diastolic state at maximum volume, to define absolute strains (which gave local fractional length) and the volume fraction. The individual strain versus ejection fraction trajectories were dependent on preload and afterload. For any one heart, however, each component of absolute strain was more tightly correlated to volume fraction. Around each linear regression, the individual measurements of absolute strain scattered with standard errors that averaged less than 7% of their range. Thus the canine hearts examined had a preferred kinematic (shape) history during ejection, different from the kinematics of filling and independent or pre-or afterload and of stroke volume.
Blood-threshold CMR volume analysis of functional univentricular heart.
Secchi, Francesco; Alì, Marco; Petrini, Marcello; Pluchinotta, Francesca Romana; Cozzi, Andrea; Carminati, Mario; Sardanelli, Francesco
2018-05-01
To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH). We evaluated retrospectively 44 FUH patients aged 25 ± 8 years (mean ± standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used. No significant difference was found between SV (median 57.7 ml; interquartile range 47.9-75.6) and aortic forward flow (57.4 ml; 48.9-80.4) (p = 0.123), with a high correlation (r = 0.789, p < 0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively. The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.
Atchaneeyasakul, Kunakorn; Leslie-Mazwi, Thabele; Donahue, Kathleen; Giese, Anne-Katrin; Rost, Natalia S
2017-10-01
Finding of white matter hyperintensity (WMH) has been associated with an increased risk of parenchymal hematoma and poor clinical outcomes after mechanical thrombectomy using old-generation endovascular devices. Currently, no data exist with regard to the risk of mechanical thrombectomy using stentriever devices in patients with significant WMH. We hypothesized that WMH volume will not affect the hemorrhagic and clinical outcome in patients with acute ischemic stroke undergoing thrombectomy using new-generation devices. A retrospective cohort of consecutive acute ischemic stroke patients >18-year-old receiving mechanical thrombectomy with stentriever devices at a single academic center was examined. WMH volume was assessed by a semiautomated volumetric analysis on T2 fluid attenuated inversion recovery-magnetic resonance imaging. Outcomes included the rate of any intracerebral hemorrhage, 90-day modified Rankin Score (mRS), the rate of good outcome (discharge mRS ≤2), and the rate of successful reperfusion (thrombolysis in cerebral ischemia score 2b or 3). Between June 2012 and December 2015, 56 patients with acute ischemic stroke met the study criteria. Median WMH volume was 6.76 cm 3 (4.84-16.09 cm 3 ). Increasing WMH volume did not significantly affect the odds of good outcome (odds ratio [OR], 0.811; 95% confidence interval [CI], 0.456-1.442), intracerebral hemorrhage (OR, 1.055; 95% CI, 0.595-1.871), parenchymal hematoma (OR, 0.353; 95% CI, 0.061-2.057), successful recanalization (OR, 1.295; 95% CI, 0.704-2.383), or death (OR, 1.583; 95% CI, 0.84-2.98). Mechanical thrombectomy using stentrievers seems to be safe in selected patients with acute ischemic stroke with large vessel occlusion, nonwithstanding the severity of WMH burden in this population. Larger prospective studies are warranted to validate these findings. © 2017 American Heart Association, Inc.
Gyöngyösi, Mariann; Wojakowski, Wojciech; Lemarchand, Patricia; Lunde, Ketil; Tendera, Michal; Bartunek, Jozef; Marban, Eduardo; Assmus, Birgit; Henry, Timothy D; Traverse, Jay H; Moyé, Lemuel A; Sürder, Daniel; Corti, Roberto; Huikuri, Heikki; Miettinen, Johanna; Wöhrle, Jochen; Obradovic, Slobodan; Roncalli, Jérome; Malliaras, Konstantinos; Pokushalov, Evgeny; Romanov, Alexander; Kastrup, Jens; Bergmann, Martin W; Atsma, Douwe E; Diederichsen, Axel; Edes, Istvan; Benedek, Imre; Benedek, Theodora; Pejkov, Hristo; Nyolczas, Noemi; Pavo, Noemi; Bergler-Klein, Jutta; Pavo, Imre J; Sylven, Christer; Berti, Sergio; Navarese, Eliano P; Maurer, Gerald
2015-04-10
The meta-Analysis of Cell-based CaRdiac study is the first prospectively declared collaborative multinational database, including individual data of patients with ischemic heart disease treated with cell therapy. We analyzed the safety and efficacy of intracoronary cell therapy after acute myocardial infarction (AMI), including individual patient data from 12 randomized trials (ASTAMI, Aalst, BOOST, BONAMI, CADUCEUS, FINCELL, REGENT, REPAIR-AMI, SCAMI, SWISS-AMI, TIME, LATE-TIME; n=1252). The primary end point was freedom from combined major adverse cardiac and cerebrovascular events (including all-cause death, AMI recurrance, stroke, and target vessel revascularization). The secondary end point was freedom from hard clinical end points (death, AMI recurrence, or stroke), assessed with random-effects meta-analyses and Cox regressions for interactions. Secondary efficacy end points included changes in end-diastolic volume, end-systolic volume, and ejection fraction, analyzed with random-effects meta-analyses and ANCOVA. We reported weighted mean differences between cell therapy and control groups. No effect of cell therapy on major adverse cardiac and cerebrovascular events (14.0% versus 16.3%; hazard ratio, 0.86; 95% confidence interval, 0.63-1.18) or death (1.4% versus 2.1%) or death/AMI recurrence/stroke (2.9% versus 4.7%) was identified in comparison with controls. No changes in ejection fraction (mean difference: 0.96%; 95% confidence interval, -0.2 to 2.1), end-diastolic volume, or systolic volume were observed compared with controls. These results were not influenced by anterior AMI location, reduced baseline ejection fraction, or the use of MRI for assessing left ventricular parameters. This meta-analysis of individual patient data from randomized trials in patients with recent AMI revealed that intracoronary cell therapy provided no benefit, in terms of clinical events or changes in left ventricular function. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01098591. © 2015 American Heart Association, Inc.
Diabetes - preventing heart attack and stroke
Diabetes complications - heart; Coronary artery disease - diabetes; CAD - diabetes; Cerebrovascular disease - diabetes ... with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood ...
Outdoor Air Pollution, Heart Attack and Stroke
Elevated outdoor ambient air particle pollution triggers heart attacks, strokes, and abnormal heart rhythms and worsens heart failure in individuals at high risk due to underlying medical conditions. Emergency Medical Services in communities are the first responders to these eme...
Lim, Ki Moo; Hong, Seung-Bae; Lee, Byong Kwon; Shim, Eun Bo; Trayanova, Natalia
2015-03-01
Using a three-dimensional electromechanical model of the canine ventricles with dyssynchronous heart failure, we investigated the relationship between severity of valve regurgitation and ventricular mechanical responses. The results demonstrated that end-systolic tension in the septum and left ventricular free wall was significantly lower under the condition of mitral regurgitation (MR) than under aortic regurgitation (AR). Stroke work in AR was higher than that in MR. On the other hand, the difference in stroke volume between the two conditions was not significant, indicating that AR may cause worse pumping efficiency than MR in terms of consumed energy and performed work.
Schaefer, Pamela W; Souza, Leticia; Kamalian, Shervin; Hirsch, Joshua A; Yoo, Albert J; Kamalian, Shahmir; Gonzalez, R Gilberto; Lev, Michael H
2015-02-01
Diffusion-weighted imaging (DWI) can reliably identify critically ischemic tissue shortly after stroke onset. We tested whether thresholded computed tomographic cerebral blood flow (CT-CBF) and CT-cerebral blood volume (CT-CBV) maps are sufficiently accurate to substitute for DWI for estimating the critically ischemic tissue volume. Ischemic volumes of 55 patients with acute anterior circulation stroke were assessed on DWI by visual segmentation and on CT-CBF and CT-CBV with segmentation using 15% and 30% thresholds, respectively. The contrast:noise ratios of ischemic regions on the DWI and CT perfusion (CTP) images were measured. Correlation and Bland-Altman analyses were used to assess the reliability of CTP. Mean contrast:noise ratios for DWI, CT-CBF, and CT-CBV were 4.3, 0.9, and 0.4, respectively. CTP and DWI lesion volumes were highly correlated (R(2)=0.87 for CT-CBF; R(2)=0.83 for CT-CBV; P<0.001). Bland-Altman analyses revealed little systemic bias (-2.6 mL) but high measurement variability (95% confidence interval, ±56.7 mL) between mean CT-CBF and DWI lesion volumes, and systemic bias (-26 mL) and high measurement variability (95% confidence interval, ±64.0 mL) between mean CT-CBV and DWI lesion volumes. A simulated treatment study demonstrated that using CTP-CBF instead of DWI for detecting a statistically significant effect would require at least twice as many patients. The poor contrast:noise ratios of CT-CBV and CT-CBF compared with those of DWI result in large measurement error, making it problematic to substitute CTP for DWI in selecting individual acute stroke patients for treatment. CTP could be used for treatment studies of patient groups, but the number of patients needed to identify a significant effect is much higher than the number needed if DWI is used. © 2014 American Heart Association, Inc.
Knowledge of Signs and Symptoms of Heart Attack and Stroke among Singapore Residents
Quah, Joy Li Juan; Yap, Susan; Cheah, Si Oon; Ng, Yih Yng; Goh, E. Shaun; Doctor, Nausheen; Leong, Benjamin Sieu-Hon; Tiah, Ling; Chia, Michael Yih Chong; Ong, Marcus Eng Hock
2014-01-01
Aim. To determine the level of knowledge of signs and symptoms of heart attack and stroke in Singapore resident population, in comparison to the global community. Methods. A population based, random sample of 7,840 household addresses was selected from a validated national sampling frame. Each participant was asked eight questions on signs and symptoms of heart attack and 10 questions on stroke. Results. The response rate was 65.2% with 4,192 respondents. The level of knowledge for preselected, common signs and symptoms of heart attack and stroke was 57.8% and 57.1%, respectively. The respondents scored a mean of 5.0 (SD 2.4) out of 8 for heart attack, while they scored a mean of 6.8 (SD 2.9) out of 10 for stroke. Respondents who were ≥50 years, with lower educational level, and unemployed/retired had the least knowledge about both conditions. The level of knowledge of signs and symptoms of heart attack and stroke in Singapore is comparable to USA and Canada. Conclusion. We found a comparable knowledge of stroke and heart attack signs and symptoms in the community to countries within the same economic, educational, and healthcare strata. However older persons, those with lower educational level and those who are unemployed/retired, require more public health education efforts. PMID:24812623
Gender-based differences in the cardiovascular response to standing
NASA Technical Reports Server (NTRS)
Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.
1991-01-01
The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.
Sudden cardiac arrest as a rare presentation of myxedema coma: case report.
Salhan, Divya; Sapkota, Deepak; Verma, Prakash; Kandel, Saroj; Abdulfattah, Omar; Lixon, Antony; Zwenge, Deribe; Schmidt, Frances
2017-01-01
Myxedema coma is a decompensated hypothyroidism which occurs due to long-standing, undiagnosed, or untreated hypothyroidism. Untreated hypothyroidism is known to affect almost all organs including the heart. It is associated with a decrease in cardiac output, stroke volume due to decreased myocardial contractility, and an increase in systemic vascular resistance. It can cause cardiac arrhythmias and the most commonly seen conduction abnormalities are sinus bradycardia, heart block, ventricular tachycardia, and torsade de pointes. The authors report a case of an elderly man who presented with sudden cardiac arrest and myxedema coma and who was successfully revived.
Prevalence of Imaging Biomarkers to Guide the Planning of Acute Stroke Reperfusion Trials.
Jiang, Bin; Ball, Robyn L; Michel, Patrik; Jovin, Tudor; Desai, Manisha; Eskandari, Ashraf; Naqvi, Zack; Wintermark, Max
2017-06-01
Imaging biomarkers are increasingly used as selection criteria for stroke clinical trials. The goal of our study was to determine the prevalence of commonly studied imaging biomarkers in different time windows after acute ischemic stroke onset to better facilitate the design of stroke clinical trials using such biomarkers for patient selection. This retrospective study included 612 patients admitted with a clinical suspicion of acute ischemic stroke with symptom onset no more than 24 hours before completing baseline imaging. Patients with subacute/chronic/remote infarcts and hemorrhage were excluded from this study. Imaging biomarkers were extracted from baseline imaging, which included a noncontrast head computed tomography (CT), perfusion CT, and CT angiography. The prevalence of dichotomized versions of each of the imaging biomarkers in several time windows (time since symptom onset) was assessed and statistically modeled to assess time dependence (not lack thereof). We created tables showing the prevalence of the imaging biomarkers pertaining to the core, the penumbra and the arterial occlusion for different time windows. All continuous imaging features vary over time. The dichotomized imaging features that vary significantly over time include: noncontrast head computed tomography Alberta Stroke Program Early CT (ASPECT) score and dense artery sign, perfusion CT infarct volume, and CT angiography collateral score and visible clot. The dichotomized imaging features that did not vary significantly over time include the thresholded perfusion CT penumbra volumes. As part of the feasibility analysis in stroke clinical trials, this analysis and the resulting tables can help investigators determine sample size and the number needed to screen. © 2017 American Heart Association, Inc.
NASA Astrophysics Data System (ADS)
Arshad, Saaid H.; Murphy, Ethan K.; Halter, Ryan J.
2016-03-01
Telemonitoring is becoming increasingly important as the proportion of the population living with cardiovascular disease (CVD) increases. Currently used health parameters in the suite of telemonitoring tools lack the sensitivity and specificity to accurately predict heart failure events, forcing physicians to play a reactive versus proactive role in patient care. A novel cardiac output (CO) monitoring device is proposed that leverages a custom smart phone application and a wearable electrical impedance tomography (EIT) system. The purpose of this work is to explore the potential of using respiratory-gated EIT to quantify stroke volume (SV) and assess its feasibility using real data. Simulations were carried out using the 4D XCAT model to create anatomically realistic meshes and electrical conductivity profiles representing the human thorax and the intrathoracic tissue. A single 5-second period respiration cycle with chest/lung expansion was modeled with end-diastole (ED) and end-systole (ES) heart volumes to evaluate how effective EIT-based conductivity changes represent clinically significant differences in SV. After establishing a correlation between conductivity changes and SV, the applicability of the respiratory-gated EIT was refined using data from the PhysioNet database to estimate the number of useful end-diastole (ED) and end-systole (ES) heart events attained over a 3.3 minute period. The area associated with conductivity changes was found to correlate to SV with a correlation coefficient of 0.92. A window of 12.5% around peak exhalation was found to be the optimal phase of the respiratory cycle from which to record EIT data. Within this window, ~47 useable ED and ES were found with a standard deviation of 28 using 3.3 minutes of data for 20 patients.
Volpato, Gian Paolo; Searles, Robert; Yu, Binglan; Scherrer-Crosbie, Marielle; Bloch, Kenneth D; Ichinose, Fumito; Zapol, Warren M
2008-04-01
Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation-like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a murine model. The impact of breathing H2S on cardiovascular function was examined using telemetry and echocardiography in awake mice. The effects of breathing H2S on carbon dioxide production and oxygen consumption were measured at room temperature and in a warmed environment. Breathing H2S at 80 parts per million by volume at 27 degrees C ambient temperature for 6 h markedly reduced heart rate, core body temperature, respiratory rate, and physical activity, whereas blood pressure remained unchanged. Echocardiography demonstrated that H2S exposure decreased both heart rate and cardiac output but preserved stroke volume. Breathing H2S for 6 h at 35 degrees C ambient temperature (to prevent hypothermia) decreased heart rate, physical activity, respiratory rate, and cardiac output without altering stroke volume or body temperature. H2S breathing seems to induce bradycardia by depressing sinus node activity. Breathing H2S for 30 min decreased whole body oxygen consumption and carbon dioxide production at either 27 degrees or 35 degrees C ambient temperature. Both parameters returned to baseline levels within 10 min after the cessation of H2S breathing. Inhalation of H2S at either 27 degrees or 35 degrees C reversibly depresses cardiovascular function without changing blood pressure in mice. Breathing H2S also induces a rapidly reversible reduction of metabolic rate at either body temperature.
Volpato, Gian Paolo; Searles, Robert; Yu, Binglan; Scherrer-Crosbie, Marielle; Bloch, Kenneth D.; Ichinose, Fumito; Zapol, Warren M.
2010-01-01
Background Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation–like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a murine model. Methods The impact of breathing H2S on cardiovascular function was examined using telemetry and echocardiography in awake mice. The effects of breathing H2S on carbon dioxide production and oxygen consumption were measured at room temperature and in a warmed environment. Results Breathing H2S at 80 parts per million by volume at 27°C ambient temperature for 6 h markedly reduced heart rate, core body temperature, respiratory rate, and physical activity, whereas blood pressure remained unchanged. Echocardiography demonstrated that H2S exposure decreased both heart rate and cardiac output but preserved stroke volume. Breathing H2S for 6 h at 35°C ambient temperature (to prevent hypothermia) decreased heart rate, physical activity, respiratory rate, and cardiac output without altering stroke volume or body temperature. H2S breathing seems to induce bradycardia by depressing sinus node activity. Breathing H2S for 30 min decreased whole body oxygen consumption and carbon dioxide production at either 27° or 35°C ambient temperature. Both parameters returned to baseline levels within 10 min after the cessation of H2S breathing. Conclusions Inhalation of H2S at either 27° or 35°C reversibly depresses cardiovascular function without changing blood pressure in mice. Breathing H2S also induces a rapidly reversible reduction of metabolic rate at either body temperature. PMID:18362598
Denial and Self-Image in Stroke, Lung Cancer, and Heart Disease Patients
ERIC Educational Resources Information Center
Levine, Jacob; Zigler, Edward
1975-01-01
Stroke, lung cancer, and heart disease patients were found to employ denial, as indicated by the relatively small difference between their real and ideal selves before and after the onset of illness. The greatest amount of denial was found for stroke patients. Cancer patients displayed more denial than did heart patients. (Author)
Metropolitan racial residential segregation and cardiovascular mortality: exploring pathways.
Greer, Sophia; Kramer, Michael R; Cook-Smith, Jessica N; Casper, Michele L
2014-06-01
Racial residential segregation has been associated with an increased risk for heart disease and stroke deaths. However, there has been little research into the role that candidate mediating pathways may play in the relationship between segregation and heart disease or stroke deaths. In this study, we examined the relationship between metropolitan statistical area (MSA)-level segregation and heart disease and stroke mortality rates, by age and race, and also estimated the effects of various educational, economic, social, and health-care indicators (which we refer to as pathways) on this relationship. We used Poisson mixed models to assess the relationship between the isolation index in 265 U.S. MSAs and county-level (heart disease, stroke) mortality rates. All models were stratified by race (non-Hispanic black, non-Hispanic white), age group (35-64 years, ≥ 65 years), and cause of death (heart disease, stroke). We included each potential pathway in the model separately to evaluate its effect on the segregation-mortality association. Among blacks, segregation was positively associated with heart disease mortality rates in both age groups but only with stroke mortality rates in the older age group. Among whites, segregation was marginally associated with heart disease mortality rates in the younger age group and was positively associated with heart disease mortality rates in the older age group. Three of the potential pathways we explored attenuated relationships between segregation and mortality rates among both blacks and whites: percentage of female-headed households, percentage of residents living in poverty, and median household income. Because the percentage of female-headed households can be seen as a proxy for the extent of social disorganization, our finding that it has the greatest attenuating effect on the relationship between racial segregation and heart disease and stroke mortality rates suggests that social disorganization may play a strong role in the elevated rates of heart disease and stroke found in racially segregated metropolitan areas.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Massie, B.; Kramer, B.L.; Topic, N.
Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responsesmore » at rest were decreases in left and right ventricular end-diastolic volumes from 388 +/- 81 to 350 +/- 77 ml and from 52 +/- 26 to 43 +/- 20 volume units, respectively, and in their corresponding filling pressures, from 24 +/- 10 to 17 +/- 9 mm Hg and 10 +/- 5 to 6 +/- 5 mm Hg. Although stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 +/- 6% to 22+/- 5% and from 25 +/- 9% to 29 +/- 11%, respectively. During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. This, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.« less
Left ventricular volume analysis as a basic tool to describe cardiac function.
Kerkhof, Peter L M; Kuznetsova, Tatiana; Ali, Rania; Handly, Neal
2018-03-01
The heart is often regarded as a compression pump. Therefore, determination of pressure and volume is essential for cardiac function analysis. Traditionally, ventricular performance was described in terms of the Starling curve, i.e., output related to input. This view is based on two variables (namely, stroke volume and end-diastolic volume), often studied in the isolated (i.e., denervated) heart, and has dominated the interpretation of cardiac mechanics over the last century. The ratio of the prevailing coordinates within that paradigm is termed ejection fraction (EF), which is the popular metric routinely used in the clinic. Here we present an insightful alternative approach while describing volume regulation by relating end-systolic volume (ESV) to end-diastolic volume. This route obviates the undesired use of metrics derived from differences or ratios, as employed in previous models. We illustrate basic principles concerning ventricular volume regulation by data obtained from intact animal experiments and collected in healthy humans. Special attention is given to sex-specific differences. The method can be applied to the dynamics of a single heart and to an ensemble of individuals. Group analysis allows for stratification regarding sex, age, medication, and additional clinically relevant covariates. A straightforward procedure derives the relationship between EF and ESV and describes myocardial oxygen consumption in terms of ESV. This representation enhances insight and reduces the impact of the metric EF, in favor of the end-systolic elastance concept advanced 4 decades ago.
Abramov, Dmitry; Haglund, Nicholas A; Di Salvo, Thomas G
2017-08-01
Although milrinone infusion is reported to benefit left ventricular function in chronic left heart failure, few insights exist regarding its effects on pulmonary circulation and right ventricular function. We retrospectively reviewed right heart catheterization data at baseline and during continuous infusion of milrinone in 69 patients with advanced heart failure and analyzed the effects on ventricular stroke work indices, pulmonary vascular resistance and pulmonary arterial compliance. Compared to baseline, milrinone infusion after a mean 58 ± 61 days improved mean left ventricular stroke work index (1540 ± 656 vs. 2079 ± 919 mmHg·mL/m 2 , p = 0.0007) to a much greater extent than right ventricular stroke work index (616 ± 346 vs. 654 ± 332, p = 0.053); however, patients with below median stroke work indices experienced a significant improvement in both left and right ventricular stroke work performance. Overall, milrinone reduced left and right ventricular filling pressures and pulmonary and systemic vascular resistance by approximately 20%. Despite an increase in pulmonary artery capacitance (2.3 ± 1.6 to 3.0 ± 2.0, p = 0.013) and a reduction in pulmonary vascular resistance (3.8 ± 2.3 to 3.0 ± 1.7 Wood units), milrinone did not reduce the transpulmonary gradient (13 ± 7 vs. 12 ± 6 mmHg, p = 0.252), the pulmonary artery pulse pressure (25 ± 10 vs. 24 ± 10, p = 0.64) or the pulmonary artery diastolic to pulmonary capillary wedge gradient (2.0 ± 6.5 vs. 2.4 ± 6.0, p = 0.353). Milrinone improved left ventricular stroke work indices to a greater extent than right ventricular stroke work indices and had beneficial effects on right ventricular net input impedance, predominantly via augmentation of left ventricular stroke volume and passive unloading of the pulmonary circuit. Patients who had the worst biventricular performance benefited the most from chronic milrinone infusion.
Ischemic Heart Disease and Stroke in Relation to Blood DNA Methylation
Baccarelli, Andrea; Wright, Robert; Bollati, Valentina; Litonjua, Augusto; Zanobetti, Antonella; Tarantini, Letizia; Sparrow, David; Vokonas, Pantel; Schwartz, Joel
2013-01-01
Background Epigenetic features such as DNA hypomethylation have been associated with conditions related to cardiovascular risk. We evaluated whether lower blood DNA methylation in heavily methylated repetitive sequences predicts the risk of ischemic heart disease and stroke. Methods We quantified blood DNA methylation of LINE-1 repetitive elements through PCR-pyrosequencing in 712 elderly individuals from the Boston-area Normative Aging Study. We estimated risk-factor adjusted relative risks (RRs) for ischemic heart disease and stroke at baseline (242 prevalent cases); as well as in incidence (44 new cases; median follow-up, 63 months); and subsequent mortality from ischemic heart disease (86 deaths; median follow-up, 75 months). Results Blood LINE-1 hypomethylation was associated with baseline ischemic heart disease (RR=2.1 [95% confidence interval = 1.2 to 4.0] for lowest vs. highest methylation quartile) and for stroke (2.5 [0.9 to 7.5]). Among participants free of baseline disease, individuals with methylation below the median also had higher risk of developing ischemic heart disease (4.0 [1.8 to 8.9]) or stroke (5.7 [0.8 to 39.5]). In the entire cohort, persons with methylation below the median had higher mortality from ischemic heart disease (3.3 [1.3 to 8.4]) and stroke (2.8 [0.6 to 14.3]). Total mortality was also increased (2.0 [1.2 to 3.3]). These results were confirmed in additional regression models using LINE-1 methylation as a continuous variable. Conclusions Subjects with prevalent IHD and stroke exhibited lower LINE-1 methylation. In longitudinal analyses, persons with lower LINE-1 methylation were at higher risk for incident ischemic heart disease and stroke, and for total mortality. PMID:20805753
Wada, Koji; Eguchi, Hisashi; Prieto-Merino, David
2016-12-01
Occupation- and industry-based risks for stroke and ischemic heart disease may vary among Japanese working-aged men. We examined the differences in mortality rates between stroke and ischemic heart disease by occupation and industry among employed Japanese men aged 25-59 years. In 2010, we obtained occupation- and industry-specific vital statistics data from the Japanese Ministry of Health, Labour, and Welfare dataset. We analyzed data for Japanese men who were aged 25-59 years in 2010, grouped in 5-year age intervals. We estimated the mortality rates of stroke and ischemic heart disease in each age group for occupation and industry categories as defined in the national census. We did not have detailed individual-level variables. We used the number of employees in 2010 as the denominator and the number of events as the numerator, assuming a Poisson distribution. We conducted separate regression models to estimate the incident relative risk for stroke and ischemic heart disease for each category compared with the reference categories "sales" (occupation) and "wholesale and retail" (industry). When compared with the reference groups, we found that occupations and industries with a relatively higher risk of stroke and ischemic heart disease were: service, administrative and managerial, agriculture and fisheries, construction and mining, electricity and gas, transport, and professional and engineering. This suggests there are occupation- and industry-based mortality risk differences of stroke and ischemic heart disease for Japanese working-aged men. These differences in risk might be explained to factors associated with specific occupations or industries, such as lifestyles or work styles, which should be explored in further research. The mortality risk differences of stroke and ischemic heart disease shown in the present study may reflect an excessive risk of Karoshi (death from overwork).
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Perflurooctanoic Acid Induces Developmental Cardiotoxicity in ...
Perfluorooctanoic acid (PFOA) is a widespread environmental contaminant that is detectable in serum of the general U.S. population. PFOA is a known developmental toxicant that induces mortality in mammalian embryos and is thought to induce toxicity via interaction with the peroxisome proliferator activated receptor alpha (PPAR_). As the cardiovascular system is crucial for embryonic survival, PFOA-induced effects on the heart may partially explain embryonic mortality. To assess impacts of PFOA exposure on the developing heart in an avian model, we used histopathology and immunohistochemical staining for myosin to assess morphological alterations in 19-day-old chicken embryo hearts after PFOA exposure. Additionally, echocardiography and cardiac myofibril ATPase activity assays were used to assess functional alterations in 1-day-old hatchling chickens following developmental PFOA exposure. Overall thinning and thinning of a dense layer of myosin in the right ventricular wall were observed in PFOA-exposed chicken embryo hearts. Alteration of multiple cardiac structural and functional parameters, including left ventricular wall thickness, left ventricular volume, heart rate, stroke volume, and ejection fraction were detected with echocardiography in the exposed hatchling chickens. Assessment of ATPase activity indicated that the ratio of cardiac myofibril calcium-independent ATPase activity to calcium-dependent ATPase activity was not affected, which suggests that d
2013-05-28
Chronic Stable Angina; Unstable Angina; Coronary Heart Disease Not Otherwise Specified; Acute Myocardial Infarction; Heart Failure; Ventricular Arrhythmias; Cardiac Arrest; Abdominal Aortic Aneurysm; Peripheral Arterial Disease; Ischaemic Stroke; Subarachnoid Haemorrhagic Stroke; Intracerebral Haemorrhagic Stroke; Stroke Not Otherwise Specified; Sudden Cardiac Death; Unheralded Coronary Death; Mortality; Coronary Heart Disease (CHD); Cardiovascular Disease (CVD); Fatal Cardiovascular Disease (Fatal CVD); ST Elevation Myocardial Infarction (STEMI); Non-ST Elevation Myocardial Infarction (nSTEMI); Myocardial Infarction Not Otherwise Specified (MI NOS)
Symptom recognition of heart attack and stroke in nine European countries: a representative survey
Mata, Jutta; Frank, Ronald; Gigerenzer, Gerd
2012-01-01
Abstract Background Cardiovascular diseases are the number one cause of death and a source of chronic disability. Objectives To assess recognition of and reaction to symptoms of heart attack and stroke, and how recognition is related to the frequency of consulting physicians and other information sources. Design Face‐to‐face computer‐assisted personal interviews. Participants Representative sample of 10 228 persons in Austria, France, Germany, Italy, the Netherlands, Poland, Russia, Spain and UK, aged 14–98. Main Outcome Variables Recognition of heart attack and stroke symptoms and proper reaction to symptoms. Results Chest pain was the only heart attack symptom recognized by more than 50% of participants. Eight percent knew no symptoms. Of 14 stroke symptoms, none was recognized by more than 50% of participants; 19% could not identify any symptom. For both heart attack and stroke, Germans and Austrians recognized the largest number of symptoms. Persons in Italy, Poland, Russia and Spain knew only about half as many symptoms as in Germany or Austria. Only 51% of Europeans would call an ambulance when someone suffers a stroke, the fewest (33 and 34%) in Germany and Austria. In most countries, people who consulted their physician more frequently had no better recognition of heart attack or stroke symptoms. Conclusions The majority of persons in nine European countries recognize few heart attack and stroke symptoms; many do not know how to react. This low level of knowledge constitutes a major health risk and likely leads to delay in treatment, contributing to the high mortality and morbidity from these diseases. PMID:22390229
Symptom recognition of heart attack and stroke in nine European countries: a representative survey.
Mata, Jutta; Frank, Ronald; Gigerenzer, Gerd
2014-06-01
Cardiovascular diseases are the number one cause of death and a source of chronic disability. To assess recognition of and reaction to symptoms of heart attack and stroke, and how recognition is related to the frequency of consulting physicians and other information sources. Face-to-face computer-assisted personal interviews. Representative sample of 10,228 persons in Austria, France, Germany, Italy, the Netherlands, Poland, Russia, Spain and UK, aged 14-98. Recognition of heart attack and stroke symptoms and proper reaction to symptoms. Chest pain was the only heart attack symptom recognized by more than 50% of participants. Eight percent knew no symptoms. Of 14 stroke symptoms, none was recognized by more than 50% of participants; 19% could not identify any symptom. For both heart attack and stroke, Germans and Austrians recognized the largest number of symptoms. Persons in Italy, Poland, Russia and Spain knew only about half as many symptoms as in Germany or Austria. Only 51% of Europeans would call an ambulance when someone suffers a stroke, the fewest (33 and 34%) in Germany and Austria. In most countries, people who consulted their physician more frequently had no better recognition of heart attack or stroke symptoms. The majority of persons in nine European countries recognize few heart attack and stroke symptoms; many do not know how to react. This low level of knowledge constitutes a major health risk and likely leads to delay in treatment, contributing to the high mortality and morbidity from these diseases. © 2012 John Wiley & Sons Ltd.
Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E
2009-01-01
Background Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. Methods A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. Results An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16–18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3–6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2–10.6)] and stroke [8.6% (95% CI 1.6–15.1)] mortality. Conclusions The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality. PMID:19188208
Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E
2009-02-01
Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16-18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3-6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2-10.6)] and stroke [8.6% (95% CI 1.6-15.1)] mortality. The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality.
Terrovitis, John V; Charitos, Christos E; Tsolakis, Elias J; Dolou, Paraskevi; Pierrakos, Charalampos N; Siafakas, Kostas X; Nanas, John N
2003-12-01
The purpose of this study was to compare the hemodynamic effectiveness of a 30-ml stroke volume paraaortic counterpulsation device (PACD), presenting the advantages of ease of implantation and driving by a standard intraaortic balloon pump (IABP) console (Datascope 96, Datascope Corp., Montvale, NJ, USA) to that of a 40-ml IABP, in the setting of experimental heart failure. In an acute heart failure model, the IABP was placed in the descending aorta and the PACD in the ascending aorta of eight pigs. Both devices were driven by the same system, and hemodynamic measurements were obtained with and without mechanical assistance. The two pumps significantly reduced the systolic and end-diastolic aortic pressures, but the PACD reduced the latter more effectively (42.6 +/- 18.1% vs 11.0 +/- 9.9%, p = 0.0001). Both pumps provided significant aortic diastolic augmentation, but the counterpulsation wave of the PACD was significantly greater (augmentation of 44.8 +/- 22.2% vs 37.6 +/- 15.6%, p = 0.031). Both lowered the end-diastolic left ventricular pressure with a trend toward PACD superiority (24.2 +/- 13.7% vs 19.7 +/- 13.5%, p = 0.064). It is concluded that the PACD, even with smaller stroke volume, is more effective than the IABP. The simplicity of its implantation, together with the ability of the standard IABP consoles to control its function, make it a promising device for mechanical assistance of the failing heart.
Body mass and cardiovascular reactivity to racism in African American college students.
Clark, Vernessa R; Hill, Oliver W
2009-01-01
The purpose of the present study was to examine the effects of body mass on cardiovascular reactivity to racism in African American college students. Cardiac output, stroke volume, heart rate and blood pressure were measured as participants viewed a racially noxious scene on videotape. Body mass was measured using body mass index calculated using height and weight. We hypothesized that obese individuals would have greater cardiovascular reactivity to the scene than overweight individuals or individuals with normal weight. We also hypothesized that obese women would have the greatest cardiovascular reactivity to the scenes compared to overweight and normal weight women, and obese, overweight, and normal weight men. Lastly, we hypothesized that women would have greater cardiovascular reactivity than their male counterparts. Multivariate analysis of variance revealed that obese participants had significantly greater stroke volume and cardiac output than participants of normal weight, indicating that obese participants were less emotionally aroused by the stressor. There was also a significant interaction between sex and body mass for heart rate reactivity between the stressor and recovery periods. Obese women had the largest drop in heart rate, while obese men had the smallest drop from the stressor period to the recovery period. The findings revealed that obese participants were less aroused by the stressors and recovered from them more quickly than overweight participants and participants of normal weight. The frequent experiences of weight prejudices by the obese group may have desensitized them to other prejudices such as the racial intolerance shown in the stressor.
Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J
2014-12-01
Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 10(13) vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 10(12) vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure-volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF.
Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J
2014-01-01
Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 1013 vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 1012 vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure–volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF. PMID:25023328
Han, June-Chiew; Guild, Sarah-Jane; Pham, Toan; Nisbet, Linley; Tran, Kenneth; Taberner, Andrew J.; Loiselle, Denis S.
2018-01-01
Pulmonary arterial hypertension (PAH) alters the geometries of both ventricles of the heart. While the right ventricle (RV) hypertrophies, the left ventricle (LV) atrophies. Multiple lines of clinical and experimental evidence lead us to hypothesize that the impaired stroke volume and systolic pressure of the LV are a direct consequence of the effect of pressure overload in the RV, and that atrophy in the LV plays only a minor role. In this study, we tested this hypothesis by examining the mechanoenergetic response of the atrophied LV to RV hypertrophy in rats treated with monocrotaline. Experiments were performed across multiple-scales: the whole-heart in vivo and ex vivo, and its trabeculae in vitro. Under the in vivo state where the RV was pressure-overloaded, we measured reduced systemic blood pressure and LV ventricular pressure. In contrast, under both ex vivo and in vitro conditions, where the effect of RV pressure overload was circumvented, we found that LV was capable of developing normal systolic pressure and stress. Nevertheless, LV atrophy played a minor role in that LV stroke volume remained lower, thereby contributing to lower LV mechanical work output. Concomitantly lower oxygen consumption and change of enthalpy were observed, and hence LV energy efficiency was unchanged. Our internally consistent findings between working-heart and trabecula experiments explain the rapid improvement of LV systolic function observed in patients with chronic pulmonary hypertension following surgical relief of RV pressure overload. PMID:29375394
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bostroem, P.A.
In order to evaluate the therapeutic effects of metoprolol, nifedipine, and their combination, 11 patients with secondary angina pectoris and with thallium tomographic findings indicating coronary artery disease were studied before and after these three treatment regimes in a single-blind cross-over study. The therapeutic effect was measured by standardized working test and isotope angiocardiography, which enabled evaluation of left ventricular ejection fraction, stroke volume, and phase analysis of left ventricular contraction. Treatment with metoprolol and combination therapy increased work performance. Ejection fraction did not differentiate the treatment regimes, whereas stroke volume was significantly lower at work and heart rate highermore » at rest and at work during nifedipine treatment compared to either metoprolol or combination treatment (p less than 0.05). Cardiac output was significantly reduced during nifedipine and metoprolol treatment during work (p less than 0.05). Phase improved after all therapeutic regimes, but reached significance only during the metoprolol treatment period at rest (p less than 0.05).« less
Cardiovascular function in pulmonary emphysema.
Visca, Dina; Aiello, Marina; Chetta, Alfredo
2013-01-01
Chronic obstructive pulmonary disease (COPD) and chronic cardiovascular disease, such as coronary artery disease, congestive heart failure, and cardiac arrhythmias, have a strong influence on each other, and systemic inflammation has been considered as the main linkage between them. On the other hand, airflow limitation may markedly affect lung mechanics in terms of static and dynamic hyperinflation, especially in pulmonary emphysema, and they can in turn influence cardiac performance as well. Skeletal mass depletion, which is a common feature in COPD especially in pulmonary emphysema patients, may have also a role in cardiovascular function of these patients, irrespective of lung damage. We reviewed the emerging evidence that highlights the role of lung mechanics and muscle mass impairment on ventricular volumes, stroke volume, and stroke work at rest and on exercise in the presence of pulmonary emphysema. Patients with emphysema may differ among COPD population even in terms of cardiovascular function.
Contributions of MSNA and stroke volume to orthostatic intolerance following bed rest
NASA Technical Reports Server (NTRS)
Shoemaker, J. K.; Hogeman, C. S.; Sinoway, L. I.
1999-01-01
We examined whether the altered orthostatic tolerance following 14 days of head-down tilt bed rest (HDBR) was related to inadequate sympathetic outflow or to excessive reductions in cardiac output during a 10- to 15-min head-up tilt (HUT) test. Heart rate, blood pressure (BP, Finapres), muscle sympathetic nerve activity (MSNA, microneurography), and stroke volume blood velocity (SVV, Doppler ultrasound) were assessed during supine 30 degrees (5 min) and 60 degrees (5-10 min) HUT positions in 15 individuals who successfully completed the pre-HDBR test without evidence of orthostatic intolerance. Subjects were classified as being orthostatically tolerant (OT, n = 9) or intolerant (OI, n = 6) following the post-HDBR test. MSNA, BP, and SVV during supine and HUT postures were not altered in the OT group. Hypotension during 60 degrees HUT in the post-bed rest test for the OI group (P < 0.05) was associated with a blunted increase in MSNA (P < 0.05). SVV was reduced following HDBR in the OI group (main effect of HDBR, P < 0.02). The data support the hypothesis that bed rest-induced orthostatic intolerance is related to an inadequate increase in sympathetic discharge that cannot compensate for a greater postural reduction in stroke volume.
Sridharan, Vijayalakshmi; Thomas, Chanice J.; Cao, Maohua; Melnyk, Stepan B.; Pavliv, Oleksandra; Joseph, Jacob; Singh, Sharda P.; Sharma, Sunil; Moros, Eduardo G.; Boerma, Marjan
2016-01-01
Background and Purpose Thoracic (chemo)radiation therapy is increasingly administered with tyrosine kinase inhibitors (TKI). While TKI have adverse effects on the heart, it is unknown whether combination with other cancer therapies causes enhanced toxicity. We used an animal model to investigate whether radiation and sunitinib interact in their effects on the heart. Material and Methods Male Sprague-Dawley rats received local heart irradiation (9 Gy per day, 5 days). Oral sunitinib (8 or 15 mg/kg bodyweight per day) started on day 1 of irradiation and continued for 2 weeks. Cardiac function was examined with echocardiography. Cardiac remodeling, cell death, left ventricular (LV) oxidative stress markers, mitochondrial morphology and membrane permeability transition pore (mPTP) opening were assessed. Results Cardiac diameter, stroke volume, and LV volume, mass and anterior wall thickness increased in time, but only in the vehicle group. Sunitinib reduced LV inner diameter and volume in systole, which were counteracted by radiation. Sunitinib and radiation showed enhanced effects on mitochondrial morphology and mPTP opening, but not on cardiac troponin I, mast cell numbers or markers of oxidative stress. Conclusions This study found no early enhanced effects of radiation and sunitinib on cardiac function or structure. Long-term effects remain to be determined. PMID:27072940
Data and Statistics: Women and Heart Disease
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30,000 fewer heart attacks and strokes in North Carolina: a challenge to prioritize prevention.
Bertoni, Alain G; Ensley, Don; Goff, David C
2012-01-01
Heart disease and stroke are leading causes of death in North Carolina and are also important contributors to poor health and excess health care expenditures. The risk factors for heart disease, stroke, and other forms of cardiovascular disease are well known, and include smoking, high blood pressure, elevated serum cholesterol levels, diabetes mellitus, and obesity. These risk factors persist as a result of suboptimal assessment, treatment, and control; adverse trends in health behaviors; and environmental and societal conditions negatively affecting the pursuit of optimal cardiovascular health. If North Carolina is to do its share in making it possible for the national Million Hearts initiative to meet its goals, then 30,000 heart attacks and strokes need to be prevented in the state over the next 5 years. Both the Million Hearts initiative and North Carolina's Justus-Warren Heart Disease and Stroke Prevention Task Force Plan include specific recommendations aimed at the primary and secondary prevention of heart disease and stroke. Million Hearts focuses on the ABCS: aspirin use when appropriate, blood pressure control, cholesterol control, and smoking cessation or abstention. The task force plan also addresses physical inactivity, poor nutrition, and the control of obesity and diabetes. The commentaries published in this issue of the NCMJ address the challenge of cardiovascular disease prevention among children and adults across the state and highlight efforts to enhance prevention via public policies and legislation, community coalitions, and quality improvement in the clinical arena.
Honda, Atsushi; Nakamura, Yuji; Ohara, Hiroshi; Cao, Xin; Nomura, Hiroaki; Katagi, Jun; Wada, Takeshi; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Sugiyama, Atsushi
2016-03-15
Cardiac effects of a prostagrandin EP4-receptor agonist ONO-AE1-329 were assessed in the halothane-anesthetized dogs under the monitoring of left ventricular pressure-volume relationship, which were compared with those of clinically recommended doses of dopamine, dobutamine and milrinone (n=4-5 for each treatment). ONO-AE1-329 was intravenously administered in doses of 0.3, 1 and 3 ng/kg/min for 10 min with a pause of 20 min. Dopamine in a dose of 3 µg/kg/min for 10 min, dobutamine in a dose of 1 µg/kg/min for 10 min and milrinone in a dose of 5 µg/kg/min for 10 min followed by 0.5 µg/kg/min for 10 min were intravenously administered. Low dose of ONO-AE1-329 increased the stroke volume. Middle dose of ONO-AE1-329 increased the cardiac output, left ventricular end-diastolic volume, ejection fraction, maximum upstroke/downstroke velocities of the left ventricular pressure and external work, but decreased the end-systolic pressure and internal work besides the change by the low dose. High dose of ONO-AE1-329 increased the heart rate and maximum elastance, but decreased the end-systolic volume besides the changes by the middle dose. Dopamine, dobutamine and milrinone exerted essentially similar cardiac effects to ONO-AE1-329, but they did not significantly change the end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, end-systolic pressure, maximum elastance, external work or internal work. Thus, EP4-receptor stimulation by ONO-AE1-329 may have potential to better promote the passive ventricular filling than the conventional cardiotonic drugs, which could become a candidate of novel therapeutic strategy for the treatment of heart failure with preserved ejection fraction. Copyright © 2016 Elsevier B.V. All rights reserved.
Bradycardia in perspective-not all reductions in heart rate need immediate intervention.
Mason, Keira P; Lönnqvist, Per-Arne
2015-01-01
According to Wikipedia, the word 'bradycardia' stems from the Greek βραδύς, bradys, 'slow', and καρδία, kardia, 'heart'. Thus, the meaning of bradycardia is slow heart rate but not necessarily too slow heart rate. If looking at top endurance athletes they may have a resting heart rate in the very low thirties without needing emergent intervention with anticholinergics, isoprenaline, epinephrine, chest compressions or the insertion of an emergency pacemaker (Figure 1). In fact, they withstand these episodes without incident, accommodating with a compensatory increase in stroke volume to preserve and maintain cardiac output. With this in mind, it is difficult for the authors to fully understand and agree with the general sentiment amongst many pediatric anesthesiologists that all isolated bradycardia portends impending doom and must be immediately treated with resuscitative measures. © 2014 John Wiley & Sons Ltd.
Age accounts for racial differences in ischemic stroke volume in a population-based study.
Zakaria, Tarek; Lindsell, Christopher J; Kleindorfer, Dawn; Alwell, Kathleen; Moomaw, Charles J; Woo, Daniel; Szaflarski, Jerzy P; Khoury, Jane; Miller, Rosie; Broderick, Joseph P; Kissela, Brett
2008-01-01
The stroke volume among black ischemic stroke patients in phase I of the population-based Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) was smaller than reported among acute stroke studies, with a median stroke volume of 2.5 cm. However, it is not known if stroke volume was similar between black and white patients within the same study population. Phase II of the GCNKSS identified all ischemic strokes between July 1993 and June 1994. The stroke volume was estimated by study physicians using the modified ellipsoid method. Analysis of stroke volume by race, sex and age was performed for strokes with a measurable lesion of >or=0.5 cm(3). Among verified cases of ischemic stroke, 334 patients were eligible for this analysis. There were 191 whites (57%) and 143 blacks (43%). The mean age was 69.4 years. The median stroke volume for all patients was 8.8 cm(3) (range 0.5-540), with a mean of 36.4 cm(3). Stroke volume was not different between men and women, and it tended to increase with age. Although stroke volume was significantly higher among whites, age was a confounding factor. Subsequent analysis of stroke volume stratified by age showed no difference between blacks and whites in any age group. Our data show that most ischemic stroke lesions, regardless of the race, are of small size, and this may be an important reason for the low percentage of strokes treated currently with tissue-type plasminogen activator. The association of age with stroke volume requires further study. Copyright 2008 S. Karger AG, Basel.
Avezum, Alvaro; Lopes, Renato D; Schulte, Phillip J; Lanas, Fernando; Gersh, Bernard J; Hanna, Michael; Pais, Prem; Erol, Cetin; Diaz, Rafael; Bahit, M Cecilia; Bartunek, Jozef; De Caterina, Raffaele; Goto, Shinya; Ruzyllo, Witold; Zhu, Jun; Granger, Christopher B; Alexander, John H
2015-08-25
Apixaban is approved for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. However, the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial included a substantial number of patients with valvular heart disease and only excluded patients with clinically significant mitral stenosis or mechanical prosthetic heart valves. We compared the effect of apixaban and warfarin on rates of stroke or systemic embolism, major bleeding, and death in patients with and without moderate or severe valvular heart disease using Cox proportional hazards modeling. Of the 18 201 patients enrolled in ARISTOTLE, 4808 (26.4%) had a history of moderate or severe valvular heart disease or previous valve surgery. Patients with valvular heart disease had higher rates of stroke or systemic embolism and bleeding than patients without valvular heart disease. There was no evidence of a differential effect of apixaban over warfarin in patients with and without valvular heart disease in reducing stroke and systemic embolism (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.51-0.97 and HR, 0.84; 95%, CI 0.67-1.04; interaction P=0.38), causing less major bleeding (HR, 0.79; 95% CI, 0.61-1.04 and HR, 0.65; 95% CI, 0.55-0.77; interaction P=0.23), and reducing mortality (HR, 1.01; 95% CI, 0.84-1.22 and HR, 0.84; 95% CI, 0.73-0.96; interaction P=0.10). More than a quarter of the patients in ARISTOTLE with nonvalvular atrial fibrillation had moderate or severe valvular heart disease. There was no evidence of a differential effect of apixaban over warfarin in reducing stroke or systemic embolism, causing less bleeding, and reducing death in patients with and without valvular heart disease. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984. © 2015 American Heart Association, Inc.
Briel, Matthias; Studer, Marco; Glass, Tracy R; Bucher, Heiner C
2004-10-15
To assess if lipid-lowering interventions (statins, fibrates, resins, n-3 fatty acids, diet) prevent nonfatal and fatal strokes in patients with and without coronary heart disease. We systematically searched the literature up to August 2002 to retrieve all randomized controlled trials of lipid-lowering interventions that reported nonfatal and fatal stroke and mortality data. The search yielded 65 trials with 200,607 patients for a meta-analysis to determine whether treatment effects differed between types of lipid-lowering interventions and between patient samples with and without coronary heart disease. The risk ratio for nonfatal and fatal stroke for statins as compared with control interventions was 0.82 (95% confidence interval [CI]: 0.76 to 0.90). The corresponding risk ratios for statins as compared with control were 0.75 (95% CI: 0.65 to 0.87) for patients with coronary heart disease and 0.77 (95% CI: 0.62 to 0.95) for those without coronary heart disease. The confidence intervals of risk ratios for nonfatal and fatal stroke associated with fibrates, resins, n-3 fatty acids, and diet all included 1, as did the confidence intervals for these interventions in patients with and without coronary heart disease. Weighted meta-regression analysis suggested a stronger association of stroke reduction with statin treatment than with the extent of cholesterol reduction. This meta-analysis suggests that statins reduce the incidence of stroke in patients with and without coronary heart disease.
Natriuretic Peptides Studies Collaboration; Willeit, Peter; Kaptoge, Stephen; Welsh, Paul; Butterworth, Adam; Chowdhury, Rajiv; Spackman, Sarah; Pennells, Lisa; Gao, Pei; Burgess, Stephen; Freitag, Daniel; Sweeting, Michael; Wood, Angela; Cook, Nancy; Judd, Suzanne; Trompet, Stella; Nambi, Vijay; Olsen, Michael; Everett, Brendan; Kee, Frank; Ärnlöv, Johan; Salomaa, Veikko; Levy, Daniel; Kauhanen, Jussi; Laukkanen, Jari; Kavousi, Maryam; Ninomiya, Toshiharu; Casas, Juan-Pablo; Daniels, Lori; Lind, Lars; Kistorp, Caroline; Rosenberg, Jens; Mueller, Thomas; Rubattu, Speranza; Panagiotakos, Demosthenes; Franco, Oscar; de Lemos, James; Luchner, Andreas; Kizer, Jorge; Kiechl, Stefan; Salonen, Jukka; Goya Wannamethee, S; de Boer, Rudolf; Nordestgaard, Børge; Andersson, Jonas; Jørgensen, Torben; Melander, Olle; Ballantyne, Christie; DeFilippi, Christopher; Ridker, Paul; Cushman, Mary; Rosamond, Wayne; Thompson, Simon; Gudnason, Vilmundur; Sattar, Naveed; Danesh, John; Di Angelantonio, Emanuele
2016-10-01
Guidelines for primary prevention of cardiovascular diseases focus on prediction of coronary heart disease and stroke. We assessed whether or not measurement of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) concentration could enable a more integrated approach than at present by predicting heart failure and enhancing coronary heart disease and stroke risk assessment. In this individual-participant-data meta-analysis, we generated and harmonised individual-participant data from relevant prospective studies via both de-novo NT-proBNP concentration measurement of stored samples and collection of data from studies identified through a systematic search of the literature (PubMed, Scientific Citation Index Expanded, and Embase) for articles published up to Sept 4, 2014, using search terms related to natriuretic peptide family members and the primary outcomes, with no language restrictions. We calculated risk ratios and measures of risk discrimination and reclassification across predicted 10 year risk categories (ie, <5%, 5% to <7·5%, and ≥7·5%), adding assessment of NT-proBNP concentration to that of conventional risk factors (ie, age, sex, smoking status, systolic blood pressure, history of diabetes, and total and HDL cholesterol concentrations). Primary outcomes were the combination of coronary heart disease and stroke, and the combination of coronary heart disease, stroke, and heart failure. We recorded 5500 coronary heart disease, 4002 stroke, and 2212 heart failure outcomes among 95 617 participants without a history of cardiovascular disease in 40 prospective studies. Risk ratios (for a comparison of the top third vs bottom third of NT-proBNP concentrations, adjusted for conventional risk factors) were 1·76 (95% CI 1·56-1·98) for the combination of coronary heart disease and stroke and 2·00 (1·77-2·26) for the combination of coronary heart disease, stroke, and heart failure. Addition of information about NT-proBNP concentration to a model containing conventional risk factors was associated with a C-index increase of 0·012 (0·010-0·014) and a net reclassification improvement of 0·027 (0·019-0·036) for the combination of coronary heart disease and stroke and a C-index increase of 0·019 (0·016-0·022) and a net reclassification improvement of 0·028 (0·019-0·038) for the combination of coronary heart disease, stroke, and heart failure. In people without baseline cardiovascular disease, NT-proBNP concentration assessment strongly predicted first-onset heart failure and augmented coronary heart disease and stroke prediction, suggesting that NT-proBNP concentration assessment could be used to integrate heart failure into cardiovascular disease primary prevention. British Heart Foundation, Austrian Science Fund, UK Medical Research Council, National Institute for Health Research, European Research Council, and European Commission Framework Programme 7. Copyright © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.
Cardiovascular effects of fenoterol under conditions of hypoxaemia.
Bremner, P; Burgess, C D; Crane, J; McHaffie, D; Galletly, D; Pearce, N; Woodman, K; Beasley, R
1992-01-01
BACKGROUND: The reason for the association of increased risk of death with fenoterol in patients with asthma in New Zealand is unknown but may relate to its cardiovascular effects. Most deaths from asthma occur outside hospital, where hypoxaemia is likely to be a complicating factor. The cardiovascular effects of fenoterol have been investigated therefore under conditions of normoxaemia and hypoxaemia. METHOD: Eight healthy men were studied on two occasions. Measurements of heart rate, blood pressure, total electromechanical systole (QS2I), electrocardiographic QTc interval, cardiac index, stroke volume, and ejection fraction were made under conditions of normoxaemia and hypoxaemia (arterial oxygen saturation 90%) before and after administration of 800 micrograms of fenoterol by a metered dose inhaler. The order in which treatments were applied was according to a Latin square design. RESULTS: Before inhalation of fenoterol hypoxaemia was associated with a significant increase in heart rate (8 beats/min) and QTc interval (15.6 ms). Under conditions of normoxaemia fenoterol caused a significant increase in heart rate (14.3 beats/min), systolic blood pressure (7.7 mm Hg), stroke volume (27.7 ml), cardiac index (1.6 1/min/m2), ejection fraction (11.48), and QTc interval (32.9 ms) and a fall in QS2I (-23.2 ms) and diastolic blood pressure (-8.4 mm Hg). Under conditions of hypoxaemia the changes after inhalation of fenoterol were similar to those recorded during normoxaemia; thus the effects of hypoxaemia and fenoterol were additive (heart rate 21.9 beats/min, QTc 43.5 ms with fenoterol and hypoxaemia). CONCLUSION: The chronotropic and electrophysiological effects of fenoterol were enhanced by conditions of hypoxaemia. PMID:1481183
Iwasaku, Toshihiro; Ando, Tomotaka; Eguchi, Akiyo; Okuhara, Yoshitaka; Naito, Yoshiro; Mano, Toshiaki; Masuyama, Tohru; Hirotani, Shinichi
2017-05-31
We hypothesized that the effects of adaptive servo-ventilation (ASV) therapy were influenced by right-sided heart performance. This study aimed to clarify the interaction between the effects of ASV and right-sided heart performance in patients with stable heart failure (HF) with reduced ejection fraction (HFrEF).Twenty-six stable HF inpatients (left ventricular ejection fraction < 0.45, without moderate to severe mitral regurgitation (MR) were analyzed. Echocardiography was performed before and after 30 minutes of ASV. ASV increased stroke volume index (SVI) in 14 patients (30.0 ± 11.9 to 41.1 ± 16.1 mL/m 2 ) and reduced SVI in 12 patients (36.0 ± 10.1 to 31.9 ± 12.2 mL/m 2 ). Multivariate linear regression analysis revealed that tricuspid annular plane systolic excursion (TAPSE) before ASV was an independent association factor for (SV during ASV - SV before ASV)/LVEDV × 100 (%) (%ΔSV/LVEDV). ROC analysis of TAPSE for %ΔSV/LVEDV > 0 showed that the cut-off point was 16.5 mm. All patients were divided into 2 groups according to the TAPSE value. Although no significant differences were found in the baseline characteristics and blood tests, there were significant differences in tricuspid lateral annular systolic velocity, TAPSE, right atrial area, and right ventricular (RV) area before ASV between patients with TAPSE ≤ 16.5 mm and those with TAPSE > 16.5 mm. Interestingly, ASV reduced RV area and increased TAPSE in patients with TAPSE ≤ 16.5 mm, while it reduced TAPSE in those > 16.5 mm.ASV therapy has the potential to increase SVI in stable HFrEF patients with low TAPSE.
Cameli, Matteo; Lisi, Matteo; Righini, Francesca Maria; Tsioulpas, Charilaos; Bernazzali, Sonia; Maccherini, Massimo; Sani, Guido; Ballo, Piercarlo; Galderisi, Maurizio; Mondillo, Sergio
2012-03-01
Right ventricular (RV) systolic function has a critical role in determining the clinical outcome and success of using left ventricular assist devices (LVADs) in patients with refractory heart failure. Tissue Doppler and M-mode measurements of tricuspid systolic motion (tricuspid S' and tricuspid annular plane systolic excursion [TAPSE]) are the most currently used methods for the quantification of RV longitudinal function; RV deformation analysis by speckle-tracking echocardiography (STE) has recently allowed the analysis of global RV longitudinal function. Using cardiac catheterization as the reference standard, this study aimed at exploring the correlation between RV longitudinal function by STE and RV stroke work index (RVSWI) in patients referred for cardiac transplantation. Right-side heart catheterization and transthoracic echo Doppler were simultaneously performed in 41 patients referred for cardiac transplantation evaluation for advanced systolic heart failure. Thermodilution RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. RV longitudinal strain (RVLS) by STE was assessed averaging all segments in apical 4-chamber view (global RVLS) and by averaging RV free-wall segments (free-wall RVLS). Tricuspid S' and TAPSE were also calculated. No significant correlations were found for TAPSE or tricuspid S' with RVSWI (r = 0.14; r = 0.06; respectively). Close negative correlations between global RVLS and free-wall RVLS with the RVSWI were found (r = -0.75; r = -0.82; respectively; both P < .0001). Furthermore, free-wall RVLS demonstrated the highest diagnostic accuracy (area under the receiver operating characteristic (ROC) curve 0.90) and good sensitivity and specificity of 92% and 86%, respectively, to predict depressed RVSWI using a cutoff value of less than -11.8%. In a group of patients referred for heart transplantation, TAPSE and tricuspid S' did not correlate with invasively obtained RVSWI. RV longitudinal deformation analysis by STE correlated well with RVSWI, providing a better estimation of RV systolic performance. Copyright © 2012 Elsevier Inc. All rights reserved.
Kreibig, Sylvia D; Wilhelm, Frank H; Roth, Walton T; Gross, James J
2007-09-01
Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), and respiratory (rate, tidal volume and its variability, inspiratory flow rate, duty cycle, and end-tidal pCO(2)) measures. Subjective emotional experience and facial behavior (Corrugator Supercilii and Zygomaticus Major EMG) served as control measures. Results indicated robust differential physiological response patterns for fear, sadness, and neutral (mean classification accuracy 85%). Findings are discussed in terms of the fight-flight and conservation-withdrawal responses and possible limitations of a valence-arousal categorization of emotion in affective space.
Helenius, Johanna; Goddeau, Richard P; Moonis, Majaz; Henninger, Nils
2016-01-01
The National Institutes of Health Stroke Scale (NIHSS) awards higher deficit scores for infarcts in the dominant hemisphere when compared with otherwise similar infarcts in the nondominant hemisphere. This has been shown to adversely affect stroke recognition, therapeutic decisions, and outcome. However, factors modifying the association between infarct side and deficit severity are incompletely understood. Thus, we sought to determine whether age and age-related leukoaraiosis alter the relation between NIHSS deficit score and the side and volume of infarction. We studied 238 patients with supratentorial, nonlacunar ischemic infarcts prospectively included in our stroke registry between January 2013 and January 2014. NIHSS deficit severity was assessed at the time of presentation. Infarct volumes were assessed by manual planimetry on diffusion-weighted imaging. Leukoaraiosis burden was graded on fluid-attenuated inversion recovery images according to the Fazekas scale and dichotomized to none-to-mild (0-2) versus severe (3-6). Multivariable linear regression with backward elimination was used to identify independent predictors of the admission NIHSS. Left-hemispheric infarction (P<0.001), severe leukoaraiosis (P=0.001), their interaction term (P=0.005), infarct volume (P<0.001), and sex (P=0.013) were independently associated with the NIHSS deficit. Analysis of the individual NIHSS components showed that severe leukoaraiosis was associated with an increase of the lateralizing components of the NIHSS in patients with right-hemispheric infarction (P<0.05). Severe leukoaraiosis substantially attenuates the classic hemispheric lateralization of the NIHSS deficit by relating to greater NIHSS scores of components that are typically assigned to left hemisphere function. © 2015 American Heart Association, Inc.
Frequency-dependent left ventricular performance in women and men.
Wainstein, Rodrigo V; Sasson, Zion; Mak, Susanna
2012-06-01
We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac catheterization-based study for force-interval relationships of the LV. HR was controlled by right atrial (RA) pacing, and LV +dP/dt(max) and volume were assessed by micromanometer-tipped catheter and Doppler echocardiography, respectively. Analysis of approximated LV pressure-volume relationships was performed using a time-varying model of elastance. External stroke work was also calculated. The relationship between HR and LV +dP/dt(max) was expressed as LV +dP/dt(max) = b + mHR. The slope (m) of the relationship was steeper in women compared with men (11.8 ± 4.0 vs. 6.1 ± 4.1 mmHg·s(-1)·beats(-1)·min(-1), P = 0.01). The greater increase in contractility in women was reproducibly observed after normalizing LV +dP/dt(max) to LV end-diastolic volume (LVVed) or by measuring end-systolic elastance. LVVed and stroke volume decreased more in women. Thus, despite greater increases in contractility, HR was associated with a lesser rise in cardiac output and a steeper fall in external stroke work in women. Compared with men, women exhibit greater inotropic responses to incremental RA pacing, which occurs at the same time as a steeper decline in external stroke work. In older adults, we observed sexual dimorphism in determinants of LV mechanical performance.
Moderate Recovery Unnecessary to Sustain High Stroke Volume during Interval Training. A Brief Report
Stanley, Jamie; Buchheit, Martin
2014-01-01
It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO2), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3-min work period, 2 min of recovery) session on two occasions. VO2, HR and Qc were largely higher during moderate-intensity (60%) compared with low-intensity (30%) (VO2, effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2) and passive (HR, ES = +2.2; Qc, ES = +1.7) recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = −0.1; 30%, ES = −0.2). To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT. Key points Moderate-intensity recovery periods may not be necessary to maintain high stroke volume during the exercise intervals of HIIT. Stroke volume did not surpass the levels attained during the exercise intervals during the recovery periods of HIIT. The practical implication of these finding is that reducing the intensity of the recovery period during a HIIT protocol may prolong the time to exhaustion, potentially allowing completion of additional high-intensity intervals increasing the time accumulated at maximal cardiac output. PMID:24790495
Spaceflight Did Not Impair Cardiovascular Responses to Upright Posture in an Elderly Astronaut
NASA Technical Reports Server (NTRS)
Rossum, Alfred C.; Ziegler, Michael G.; Meck, Janice V.
2001-01-01
Some of the cardiovascular changes associated with spaceflight have similarities to those associated with aging. We studied the neuroendocrine and hemodynamic responses to upright posture in a 77 year old astronaut before and after spaceflight and compared them to those of a group of 20 younger (41 plus or minus 1 years) astronauts. While arterial pressure responses to standing were similar between the young and old astronauts, hemodynamic profiles were quite different. The elderly astronaut achieved adequate standing arterial pressure primarily by maintaining stroke volume and thus cardiac output. In spite of very high norepinephrine release, he had very little increase in heart rate or total peripheral resistance. This pattern persisted on all test occasions. These responses suggest high sympathetic responses, down-regulated adrenergic receptors and decreased venous compliance typical of aging. In contrast, younger astronauts did not maintain stroke volume or cardiac output with standing, but had significant increases in heart rate and resistance. These results suggest that this elderly subject had cardiovascular responses to standing that are expected in an aged person. These responses were not deleteriously affected by spaceflight. We suggest that healthy, fit elderly individuals are able to withstand the stresses of extreme environments and are not necessarily limited in their activities simply due to their chronological age.
Hemodynamic changes during whole body surface cooling and lower body negative pressure
NASA Technical Reports Server (NTRS)
Raven, P. B.; Pape, G.; Taylor, W. F.; Gaffney, F. A.; Blomqvist, C. G.
1981-01-01
Six young healthy male subjects were studied to evaluate the use of whole body surface cooling (WBSC) as an antiorthostatic intervention. Previous studies have demonstrated that perfusion of an Apollo cooling garment with 16 C water produced a significant increase in stroke volume and decrease in heart rate at rest and during lower body negative pressure (LBNP). However, optimal perfusion temperatures have not been determined. The present study examined the effects of WBSC using perfusion of water at a temperature of 10 C. This perfusion temperature produced a greater decrease in mean skin temperature than water at 16 C (4 C drop compared to 2 C). The hemodynamic effects were also more prominent with 10 C water as shown by the increase in stroke volume of 11% at rest and of 35% during LBNP at -50 torr compared to control measurements at ambient temperature. Heart rates were lowered significantly (8 beats/min) and systolic arterial blood pressure was higher (8 torr). Cooling with 10 C water produced a slight increase in muscle tone, reflected by a small but significant increase (+84 ml/min) in oxygen uptake. These data suggest that WBSC is an effective nonpharmacologic means of controlling preload and deserves further investigation as an antiorthostatic intervention.
Tsai, Chung-Fen; Anderson, Niall; Thomas, Brenda; Sudlow, Cathie L M
2015-06-01
Chinese populations are reported to have a different distribution of ischemic stroke subtypes compared with Caucasians. To understand this better, we aimed to evaluate the differences in prevalence of risk factors in ischemic stroke and their distributions among ischemic stroke subtypes in Chinese vs. Caucasians. We systematically sought studies conducted since 1990 with data on frequency of risk factors among ischemic stroke subtypes in Chinese or Caucasians. For each risk factor, we calculated study-specific and random effects pooled estimates in Chinese and Caucasians separately for: prevalence among ischemic stroke; odds ratios, comparing prevalence for each ischemic stroke subtype vs. all others. We included seven studies among 16,199 Chinese, and eleven among 16,189 Caucasian ischemic stroke patients. Risk factors studied were hypertension, diabetes, atrial fibrillation, ischemic heart disease, hypercholesterolemia, smoking and alcohol. Chinese ischemic stroke patients had younger onset of stroke than Caucasians, similar prevalence of hypertension, diabetes, smoking and alcohol, and significantly lower prevalence of atrial fibrillation, ischemic heart disease and hypercholesterolemia. Risk factor associations with ischemic stroke subtypes were mostly similar among Chinese and Caucasian ischemic stroke patients. Compared with all other ischemic subtypes, diabetes was more common in large artery stroke, atrial fibrillation and ischemic heart disease in cardioembolic stroke, and hypertension and diabetes in lacunar stroke. Our study showed a lower prevalence of atrial fibrillation, ischemic heart disease and hypercholesterolemia in Chinese, and mostly similar risk factor associations in Chinese and Caucasian ischemic stroke patients. Further analyses of individual patient data to allow adjustment for confounders are needed to confirm and extend these findings. © 2015 World Stroke Organization.
Ikehara, Satoyo; Iso, Hiroyasu; Yamagishi, Kazumasa; Kokubo, Yoshihiro; Saito, Isao; Yatsuya, Hiroshi; Inoue, Manami; Tsugane, Shoichiro
2013-11-01
The study aims to examine the association between a wide range of alcohol consumption and risk of stroke and coronary heart disease. The Japan Public Health Center-based prospective study was initiated in 1990 in Cohort I and in 1993 in Cohort II, with follow-up until 2009. The sample consisted of 47,100 women aged 40-69 years. During an average of 16.7-years, the incidence of 1846 strokes and 292 coronary heart diseases was observed. Heavy drinking (≥ 300 gethanol/week) was associated with increased risk of total stroke. The multivariable hazard ratios for heavy versus occasional drinkers were 2.19 (95% confidence interval: 1.45-3.30) for total stroke, 2.25 (1.29-3.91) for hemorrhagic stroke, 2.24 (1.05-4.76) for intraparenchymal hemorrhage, 2.26 (1.01-5.09) for subarachnoid hemorrhage and 2.04 (1.09-3.82) for ischemic stroke. In the exposure-updated analysis, the positive association between heavy drinking and risks of total stroke, hemorrhagic stroke and intraparenchymal hemorrhage became more evident. Light drinking (<150 gethanol/week) was not associated with risk of ischemic stroke. There was also no association between alcohol consumption and risk of coronary heart disease. Heavy drinking was associated with increased risk of hemorrhagic and ischemic strokes among Japanese women. © 2013.
Predicted Hemodynamic Benefits Of Counterpulsation Therapy Using A Superficial Surgical Approach
Giridharan, Guruprasad A.; Pantalos, George M.; Litwak, Kenneth N.; Spence, Paul A.; Koenig, Steven C.
2010-01-01
A volume-displacement counterpulsation device (CPD) intended for chronic implantation via a superficial surgical approach is proposed. The CPD is a pneumatically driven sac that fills during native heart systole and empties during diastole through a single, valveless cannula anastomosed to the subclavian artery. Computer simulation was performed to predict and compare the physiological responses of the CPD to the intraaortic balloon pump (IABP) in a clinically relevant model of early stage heart failure. The effect of device stroke volume (0–50 ml) and control modes (timing, duration, morphology) on landmark hemodynamic parameters and the LV pressure–volume relationship were investigated. Simulation results predicted that the CPD would provide hemodynamic benefits comparable to an IABP as evidenced by up to 25% augmentation of peak diastolic aortic pressure, which increases diastolic coronary perfusion by up to 34%. The CPD may also provide up to 34% reduction in LV end-diastolic pressure and 12% reduction in peak systolic aortic pressure, lowering LV workload by up to 26% and increasing cardiac output by up to 10%. This study demonstrated that the superficial CPD technique may be used acutely to achieve similar improvements in hemodynamic function as the IABP in early stage heart failure patients. PMID:16436889
Zhu, Zhengbao; Zhong, Chongke; Xu, Tian; Wang, Aili; Peng, Yanbo; Xu, Tan; Peng, Hao; Chen, Chung-Shiuan; Wang, Jinchao; Ju, Zhong; Li, Qunwei; Geng, Deqin; Sun, Yingxian; Du, Qingjuan; Li, Yongqiu; Chen, Jing; Zhang, Yonghong; He, Jiang
2017-08-01
The association between heart rate and prognosis of ischemic stroke remains debatable, and whether renal function status influences the relationship between them is still not elucidated. A total of 3923 ischemic stroke patients were included in this prospective multicenter study from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS). The primary outcome was a combination of death and major disability (modified Rankin Scale score ≥3) at 3 months after stroke. Secondary outcomes were, separately, death and major disability. The association between heart rate tertiles and primary outcome was appreciably modified by renal function status (p interaction = 0.037). After multivariate adjustment, high heart rate was associated with increased risk of primary outcome in patients with abnormal renal function (odds ratio, 1.61; 95% confidence interval, 1.02-2.54; p trend = 0.039) but not in patients with normal renal function (odds ratio, 0.96; 95% confidence interval, 0.75-1.23; p trend = 0.741), when two extreme tertiles were compared. Each 10 bpm increase of heart rate was associated with 21% (95% CI: 1%-44%) increased risk of primary outcome, and a linear association between heart rate and risk of primary outcome was observed among patients with abnormal renal function (p for linearity = 0.002). High heart rate may be merely a strong predictor of poor prognosis in acute ischemic stroke patients with abnormal renal function, suggesting that heart rate reduction should be applied to ischemic stroke patients with abnormal renal function to improve their prognosis. Copyright © 2017 Elsevier B.V. All rights reserved.
Heart Rate and Initial Presentation of Cardiovascular Diseases (Caliber)
2013-09-17
Abdominal Aortic Aneurysm; Coronary Heart Disease NOS; Unheralded Coronary Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest, Sudden Cardiac Death
Zhou, Huanhuan; Wang, Xiaoyun; Zhu, Junya; Fish, Anne; Kong, Weimin; Li, Fan; Liu, Lin; Yuan, Xiaodan; Gao, Xin; Lou, Qingqing
2018-03-01
To examine the association of carotid artery plaque with the incident coronary heart disease and stroke events in Chinese patients and explore whether the association differs between patients with and without hyperglycemia. We evaluated plaque, and blood pressure, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting serum insulin, fasting plasma glucose, 2 h postprandial glucose and Homeostasis model assessment of insulin resistance in 253 Chinese patients. T-test and X 2 test were used to compare the clinical characteristics and Binary logistic regression was applied to analyze the association of coronary heart disease and stroke between patients with and without hyperglycemia. Among 253 patients, 162 patients had hyperglycemia (i. e., diabetes, impaired glucose regulation and stress induced hyperglycemia) and 155 (61.3%) patients had plaque. Fasting plasma glucose, 2 h postprandial glucose and Homeostasis model assessment of insulin resistance, triglycerides, plaque were significantly higher in the hyperglycemia group than non-hyperglycemia. The incident coronary heart disease and stroke events in patients with plaque were 2.254 (95%CI,1.203-4.224) and 2.437 (95%CI,1.042-5.701) times higher than those without plaque, respectively. Among hyperglycemia subgroup, plaque was an independent risk factor for coronary heart disease (OR,3.075,95%CI,1.353-6.992) and stroke (OR,3.571,95%CI,1.460-8.737). The slopes (associations between coronary heart disease/stroke and plaque) were steeper in the hyperglycemia group than those in the non-hyperglycemia group (coronary heart disease OR,3.075 vs. 2.614; stroke OR,3.571 vs. 3.307). The incident coronary heart disease and stroke events in patients with plaque were higher than those without plaque, and this difference was more pronounced for patients with hyperglycemia vs. those without hyperglycemia. © Georg Thieme Verlag KG Stuttgart · New York.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Massie, B.; Kramer, B.L.; Topic, N.
Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg of oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responsesmore » at rest were decreases in left and right ventricular end-diastolic volumes from 388 + 81 to 350 + 77 ml (p < 0.01) and from 52 + 26 to 43 + 20 volume units (p < 0.01), respectively, and in their corresponding filling pressures, from 24 + 10 to 17 + 9 mm Hg and 10 + 5 to and + 5 mm Hg (both p < 0.01). Altough stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 + 6% to 22 + 5% and from 25 + 9% to 29 + 11%, respectively (both p < 0.01). During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. Thus, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.« less
Neural Control of the Cardiovascular System in Space
NASA Technical Reports Server (NTRS)
Levine, Benjamin D.; Pawelczyk, James A.; Zuckerman, Julie; Zhang, Rong; Fu, Qi; Iwasaki, Kenichi; Ray, Chet; Blomqvist, C. Gunnar; Lane, Lynda D.; Giller, Cole A.
2003-01-01
During the acute transition from lying supine to standing upright, a large volume of blood suddenly moves from the chest into the legs. To prevent fainting, the blood pressure control system senses this change immediately, and rapidly adjusts flow (by increasing heart rate) and resistance to flow (by constricting the blood vessels) to restore blood pressure and maintain brain blood flow. If this system is inadequate, the brain has a backup plan. Blood vessels in the brain can adjust their diameter to keep blood flow constant. If blood pressure drops, the brain blood vessels dilate; if blood pressure increases, the brain blood vessels constrict. This process, which is called autoregulation, allows the brain to maintain a steady stream of oxygen, even when blood pressure changes. We examined what changes in the blood pressure control system or cerebral autoregulation contribute to the blood pressure control problems seen after spaceflight. We asked: (1) does the adaptation to spaceflight cause an adaptation in the blood pressure control system that impairs the ability of the system to constrict blood vessels on return to Earth?; (2) if such a defect exists, could we pinpoint the neural pathways involved?; and (3) does cerebral autoregulation become abnormal during spaceflight, impairing the body s ability to maintain constant brain blood flow when standing upright on Earth? We stressed the blood pressure control system using lower body negative pressure, upright tilt, handgrip exercise, and cold stimulation of the hand. Standard cardiovascular parameters were measured along with sympathetic nerve activity (the nerve activity causing blood vessels to constrict) and brain blood flow. We confirmed that the primary cardiovascular effect of spaceflight was a postflight reduction in upright stroke volume (the amount of blood the heart pumps per beat). Heart rate increased appropriately for the reduction in stroke volume, thereby showing that changes in heart rate regulation alone cannot be responsible for orthostatic hypotension after spaceflight. All of the astronauts in our study had an increase in sympathetic nerve activity during upright tilting on Earth postflight. This increase was well calibrated for the reduction in stroke volume induced by the upright posture. The results obtained from stimulating the sympathetic nervous system using handgrip exercise or cold stress were also entirely normal during and after spaceflight. No astronaut had reduced cerebral blood flow during upright tilt, and cerebral autoregulation was normal or even enhanced inflight. These experiments show that the cardiovascular adaptation to spaceflight does not lead to a defect in the regulation of blood vessel constriction via sympathetic nerve activity. In addition, cerebral autoregulation is well-maintained. It is possible that despite the increased sympathetic nerve activity, blood vessels did not respond with a greater degree of constriction than occurred preflight, possibly uncovering a limit of vasoconstrictor reserve.
Swanoski, Michael T; Lutfiyya, May Nawal; Amaro, Maria L; Akers, Michael F; Huot, Krista L
2012-06-01
Understanding the signs and symptoms of heart attacks and strokes are important not only in saving lives, but also in preserving quality of life. Findings from recent research have yielded that the prevalence of cardiovascular disease risk factors are higher in rural populations, suggesting that adults living in rural locales may be at higher risk for heart attack and/or stroke. Knowledge of heart attack and stroke symptomology as well as calling 911 for a suspected heart attack or stroke are essential first steps in seeking care. This study sought to examine the knowledge of heart attack and stroke symptoms among rural adults in comparison to non-rural adults living in the U.S. Using multivariate techniques, a cross-sectional analysis of an amalgamated multi-year Behavioral Risk Factor Surveillance Survey (BRFSS) database was performed. The dependent variable for this analysis was low heart attack and stroke knowledge score. The covariates for the analysis were: age, sex, race/ethnicity, annual household income, attained education, health insurance status, having a health care provider (HCP), timing of last routine medical check-up, medical care deferment because of cost, self-defined health status and geographic locale. The weighted n for this study overall was 103,262,115 U.S. adults > =18 years of age. Approximately 22.0% of these respondents were U.S. adults living in rural locales. Logistic regression analysis revealed that those U.S. adults who had low composite heart attack and stroke knowledge scores were more likely to be rural (OR=1.218 95%CI 1.216-1.219) rather than non-rural residents. Furthermore, those with low scores were more likely to be: male (OR=1.353 95%CI 1.352-1.354), >65 years of age (OR=1.369 95%CI 1.368-1.371), African American (OR=1.892 95%CI 1.889-1.894), not educated beyond high school (OR=1.400 955CI 1.399-1.402), uninsured (OR=1.308 95%CI 1.3-6-1.310), without a HCP (OR=1.216 95%CI 1.215-1.218), and living in a household with an annual income of < $50,000 (OR=1.429 95%CI 1.428-1.431). Analysis identified clear disparities between the knowledge levels U.S. adults have regarding heart attack and stroke symptoms. These disparities should guide educational endeavors focusing on improving knowledge of heart attack and stroke symptoms.
2012-01-01
Background Understanding the signs and symptoms of heart attacks and strokes are important not only in saving lives, but also in preserving quality of life. Findings from recent research have yielded that the prevalence of cardiovascular disease risk factors are higher in rural populations, suggesting that adults living in rural locales may be at higher risk for heart attack and/or stroke. Knowledge of heart attack and stroke symptomology as well as calling 911 for a suspected heart attack or stroke are essential first steps in seeking care. This study sought to examine the knowledge of heart attack and stroke symptoms among rural adults in comparison to non-rural adults living in the U.S. Methods Using multivariate techniques, a cross-sectional analysis of an amalgamated multi-year Behavioral Risk Factor Surveillance Survey (BRFSS) database was performed. The dependent variable for this analysis was low heart attack and stroke knowledge score. The covariates for the analysis were: age, sex, race/ethnicity, annual household income, attained education, health insurance status, having a health care provider (HCP), timing of last routine medical check-up, medical care deferment because of cost, self-defined health status and geographic locale. Results The weighted n for this study overall was 103,262,115 U.S. adults > =18 years of age. Approximately 22.0% of these respondents were U.S. adults living in rural locales. Logistic regression analysis revealed that those U.S. adults who had low composite heart attack and stroke knowledge scores were more likely to be rural (OR = 1.218 95%CI 1.216-1.219) rather than non-rural residents. Furthermore, those with low scores were more likely to be: male (OR = 1.353 95%CI 1.352-1.354), >65 years of age (OR = 1.369 95%CI 1.368-1.371), African American (OR = 1.892 95%CI 1.889-1.894), not educated beyond high school (OR = 1.400 955CI 1.399-1.402), uninsured (OR = 1.308 95%CI 1.3-6-1.310), without a HCP (OR = 1.216 95%CI 1.215-1.218), and living in a household with an annual income of < $50,000 (OR = 1.429 95%CI 1.428-1.431). Conclusions Analysis identified clear disparities between the knowledge levels U.S. adults have regarding heart attack and stroke symptoms. These disparities should guide educational endeavors focusing on improving knowledge of heart attack and stroke symptoms. PMID:22490185
Braun, Fabian; Proença, Martin; Adler, Andy; Riedel, Thomas; Thiran, Jean-Philippe; Solà, Josep
2018-01-01
Cardiac output (CO) and stroke volume (SV) are parameters of key clinical interest. Many techniques exist to measure CO and SV, but are either invasive or insufficiently accurate in clinical settings. Electrical impedance tomography (EIT) has been suggested as a noninvasive measure of SV, but inconsistent results have been reported. Our goal is to determine the accuracy and reliability of EIT-based SV measurements, and whether advanced image reconstruction approaches can help to improve the estimates. Data were collected on ten healthy volunteers undergoing postural changes and exercise. To overcome the sensitivity to heart displacement and thorax morphology reported in previous work, we used a 3D EIT configuration with 2 planes of 16 electrodes and subject-specific reconstruction models. Various EIT-derived SV estimates were compared to reference measurements derived from the oxygen uptake. Results revealed a dramatic impact of posture on the EIT images. Therefore, the analysis was restricted to measurements in supine position under controlled conditions (low noise and stable heart and lung regions). In these measurements, amplitudes of impedance changes in the heart and lung regions could successfully be derived from EIT using ECG gating. However, despite a subject-specific calibration the heart-related estimates showed an error of 0.0 ± 15.2 mL for absolute SV estimation. For trending of relative SV changes, a concordance rate of 80.9% and an angular error of -1.0 ± 23.0° were obtained. These performances are insufficient for most clinical uses. Similar conclusions were derived from lung-related estimates. Our findings indicate that the key difficulty in EIT-based SV monitoring is that purely amplitude-based features are strongly influenced by other factors (such as posture, electrode contact impedance and lung or heart conductivity). All the data of the present study are made publicly available for further investigations.
Proença, Martin; Adler, Andy; Riedel, Thomas; Thiran, Jean-Philippe; Solà, Josep
2018-01-01
Cardiac output (CO) and stroke volume (SV) are parameters of key clinical interest. Many techniques exist to measure CO and SV, but are either invasive or insufficiently accurate in clinical settings. Electrical impedance tomography (EIT) has been suggested as a noninvasive measure of SV, but inconsistent results have been reported. Our goal is to determine the accuracy and reliability of EIT-based SV measurements, and whether advanced image reconstruction approaches can help to improve the estimates. Data were collected on ten healthy volunteers undergoing postural changes and exercise. To overcome the sensitivity to heart displacement and thorax morphology reported in previous work, we used a 3D EIT configuration with 2 planes of 16 electrodes and subject-specific reconstruction models. Various EIT-derived SV estimates were compared to reference measurements derived from the oxygen uptake. Results revealed a dramatic impact of posture on the EIT images. Therefore, the analysis was restricted to measurements in supine position under controlled conditions (low noise and stable heart and lung regions). In these measurements, amplitudes of impedance changes in the heart and lung regions could successfully be derived from EIT using ECG gating. However, despite a subject-specific calibration the heart-related estimates showed an error of 0.0 ± 15.2 mL for absolute SV estimation. For trending of relative SV changes, a concordance rate of 80.9% and an angular error of −1.0 ± 23.0° were obtained. These performances are insufficient for most clinical uses. Similar conclusions were derived from lung-related estimates. Our findings indicate that the key difficulty in EIT-based SV monitoring is that purely amplitude-based features are strongly influenced by other factors (such as posture, electrode contact impedance and lung or heart conductivity). All the data of the present study are made publicly available for further investigations. PMID:29373611
NASA Technical Reports Server (NTRS)
1980-01-01
Left ventricular stroke volume was estimated from the systolic velocity integral in the ascending aorta by pulsed Doppler Echocardiography (PDE) and the cross sectional area of the aorta estimated by M mode echocardiography on 15 patients with coronary disease undergoing right catheterization for diagnostic purposes. Cardiac output was calculated from stroke volume and heart volume using the PDE method as well as the Fick procedure for comparison. The mean value for the cardiac output via the PDE method (4.42 L/min) was only 6% lower than for the cardiac output obtained from the Fick procedure (4.69 L/min) and the correlation between the two methods was excellent (r=0.967, p less than .01). The good agreement between the two methods demonstrates that the PDE technique offers a reliable noninvasive alternative for estimating cardiac output, requiring no active cooperation by the subject. It was concluded that the Doppler method is superior to the Fick method in that it provides beat by beat information on cardiac performance.
Circulatory failure during severe hyperthermia in dog.
Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S
1983-01-01
The effect of acute hyperthermia on circulatory function was studied in 6 mongrel dogs. At a core temperature of about 40 degrees C, central venous pressure and stroke volume were maintained at almost normal level. Cardiac output significantly increased (26 ml/(kg . min)) while systemic vascular resistance significantly decreased (1.2 mmHg . sec/ml). In addition, significant decrease in vascular compliance by 40% was observed. When body temperature was raised further (severe hyperthermia), an abrupt fall of arterial pressure was observed at the rectal temperature of about 41-42 degrees C. Concomitant decreases in central venous pressure (3 mmHg), stroke volume (2.1 ml/beat) and cardiac output (29 ml/(kg . min)) were observed while heart rate increased (48 beats/min). These results suggest that the decrease in cardiac output during severe hyperthermia is due to the fall of central venous pressure, and the fall was attributed to the increase in unstressed vascular volume of systemic circulation due to the heat-induced cutaneous vasodilation. The observed decrease in systemic vascular compliance is considered to have a significant role in the maintenance of central venous pressure under hyperthermia.
Kanjanahattakij, Napatt; Sirinvaravong, Natee; Aguilar, Francisco; Agrawal, Akanksha; Krishnamoorthy, Parasuram; Gupta, Shuchita
2018-01-01
In patients with heart failure with preserved ejection fraction (HFpEF), worse kidney function is associated with worse overall cardiac mechanics. Right ventricular stroke work index (RVSWI) is a parameter of right ventricular function. The aim of our study was to determine the relationship between RVSWI and glomerular filtration rate (GFR) in patients with HFpEF. This was a single-center cross-sectional study. HFpEF is defined as patients with documented heart failure with ejection fraction > 50% and pulmonary wedge pressure > 15 mm Hg from right heart catheterization. RVSWI (normal value 8-12 g/m/beat/m2) was calculated using the formula: RVSWI = 0.0136 × stroke volume index × (mean pulmonary artery pressure - mean right atrial pressure). Univariate and multivariate linear regression analysis was performed to study the correlation between RVSWI and GFR. Ninety-one patients were included in the study. The patients were predominantly female (n = 64, 70%) and African American (n = 61, 67%). Mean age was 66 ± 12 years. Mean GFR was 59 ± 35 mL/min/1.73 m2. Mean RVSWI was 11 ± 6 g/m/beat/m2. Linear regression analysis showed that there was a significant independent inverse relationship between RVSWI and GFR (unstandardized coefficient = -1.3, p = 0.029). In the subgroup with combined post and precapillary pulmonary hypertension (Cpc-PH) the association remained significant (unstandardized coefficient = -1.74, 95% CI -3.37 to -0.11, p = 0.04). High right ventricular workload indicated by high RVSWI is associated with worse renal function in patients with Cpc-PH. Further prospective studies are needed to better understand this association. © 2018 S. Karger AG, Basel.
Poor sleep linked to increased risk of heart attack and stroke.
2017-04-19
Insomnia is associated with an increased risk of heart attack and stroke, according to a study in China. Researchers carried out a meta-analysis of 15 cohort studies to assess the association between insomnia symptoms and incidence or death from cardiovascular disease and stroke.
Sandset, Else Charlotte; Berge, Eivind; Kjeldsen, Sverre E; Julius, Stevo; Holzhauer, Björn; Krarup, Lars-Henrik; Hua, Tsushung A
2014-01-01
Risk factors for first stroke are well established, but less is known about risk factors for recurrent stroke. In the present analysis, we aimed to assess the effect of heart rate and other possible predictors of stroke in a hypertensive population with previous stroke or transient ischemic attack (TIA). The Valsartan Antihypertensive Long-Term Use Evaluation trial was a multicentre, double-masked, randomized controlled, parallel group trial comparing the effects of an angiotensin receptor blocker (valsartan) and a calcium channel blocker (amlodipine) in patients with hypertension and high cardiovascular risk. We used Cox proportional hazard models to investigate the effect of baseline variables on the risk of stroke. Quadratic terms of the continuous variables were entered in the models to test for linearity. Of 15,245 patients included in the trial, 3014 had a previous stroke or TIA at baseline and were included in the present analysis. Stroke recurrence occurred in 239 patients (7.9%) during a median of 4.5 years of follow-up. Resting heart rate (per 10 beats per minute; hazard ratio [HR], 2.78; 95% confidence interval [CI], 1.18-6.58) and diabetes mellitus at baseline (HR, 1.47; 95% CI, 1.03-2.10) were significantly associated with an increased risk of stroke recurrence in the multivariable analysis. In high-risk, hypertensive patients with previous stroke or TIA, resting heart rate was the strongest predictor of recurrent stroke. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Stewart, Tara L; Chipperfield, Judith G; Perry, Raymond P; Hamm, Jeremy M
2016-01-01
This study assessed the extent to which older adults attribute a recent heart attack/stroke to "old age," and examined consequences for subsequent lifestyle behavior and health-care service utilization. Community-dwelling adults (N = 57, ages 73-98 years) were interviewed about their heart attack/stroke, and an objective health registry provided data on health-care utilization over a 3-year period. Endorsement of "old age" as a cause of heart attack/stroke negatively predicted lifestyle behavior change, and positively predicted frequency of physician visits and likelihood of hospitalization over the subsequent 3 years. Findings suggest the importance of considering "old age" attributions in the context of cardiovascular health events. © The Author(s) 2014.
Cho, Sung M; Moazami, Nader; Frontera, Jennifer A
2017-08-01
Ischemic stroke and intracranial hemorrhage (ICH) following left ventricular assist device (LVAD) placement are major causes of morbidity. The incidence and mortality associated with these events stratified by device type have not been systematically explored. A systematic review of PubMed was conducted from January 2007 through June 2016 for all English-language articles involving HeartMate II (HMII) and HeartWare LVAD patients. Ischemic stroke and/or ICH incidence (events per patient-year) and associated mortality rates were abstracted for each device type. Of 735 articles reviewed, 48 (11,310 patients) met inclusion criteria (33 HMII, six HeartWare, eight both devices, and one unspecified). The median duration of device support was 112 days (total 13,723 patient-years). Overall, ischemic stroke or ICH occurred in 9.8% (1110 persons and 0.08 events per patient year [EPPY]). Ischemic stroke occurred in a median of 6.0% or 0.06 EPPY (range 0-16% or 0-0.21 EPPY) of HMII patients versus 7.5% or 0.09 EPPY (range 4-17.1% or 0.01-0.94 EPPY) of HeartWare patients. ICH occurred in a median of 3.0% or 0.04 EPPY (range 0-13.5% or 0-0.13 EPPY) of HMII and 8.0% or 0.08 EPPY (range 3-23% or 0.01-0.56 EPPY) of HeartWare patients. The median mortality rate for LVAD-associated ischemic stroke was 31% (HMII: 33%, [range 2.4-75%] and HeartWare: 11.5% [range 3.9-40%]), and the median mortality rate following ICH was 71% (HMII: 75%, [range 3.9-100%] and HeartWare: 44%, [range 3.1-88%]). Ischemic stroke and ICH are common after LVAD placement, but heterogeneous event rates are reported in the literature. Given the high associated mortality, further prospective study is warranted.
Li, Tiantian; Horton, Radley M; Bader, Daniel A; Liu, Fangchao; Sun, Qinghua; Kinney, Patrick L
2018-03-01
Changing climates have been causing variations in the number of global ischemic heart disease and stroke incidences, and will continue to affect disease occurrence in the future. To project temperature-related mortality for acute ischemic heart disease, and ischemic and hemorrhagic stroke with concomitant climate warming. We estimated the exposure-response relationship between daily cause-specific mortality and daily mean temperature in Beijing. We utilized outputs from 31 downscaled climate models and two representative concentration pathways (RCPs) for the 2020s, 2050s, and 2080s. This strategy was used to estimate future net temperature along with heat- and cold-related deaths. The results for predicted temperature-related deaths were subsequently contrasted with the baseline period. In the 2080s, using the RCP8.5 and no population variation scenarios, the net total number of annual temperature-related deaths exhibited a median value of 637 (with a range across models of 434-874) for ischemic stroke; this is an increase of approximately 100% compared with the 1980s. The median number of projected annual temperature-related deaths was 660 (with a range across models of 580-745) for hemorrhagic stroke (virtually no change compared with the 1980s), and 1683 (with a range across models of 1351-2002) for acute ischemic heart disease (a slight increase of approximately 20% compared with the 1980s). In the 2080s, the monthly death projection for hemorrhagic stroke and acute ischemic heart disease showed that the largest absolute changes occurred in summer and winter while the largest absolute changes for ischemic stroke occurred in summer. We projected that the temperature-related mortality associated with ischemic stroke will increase dramatically due to climate warming. However, projected temperature-related mortality pertaining to acute ischemic heart disease and hemorrhagic stroke should remain relatively stable over time. Copyright © 2017 Elsevier Ltd. All rights reserved.
Ovbiagele, Bruce; Goldstein, Larry B; Higashida, Randall T; Howard, Virginia J; Johnston, S Claiborne; Khavjou, Olga A; Lackland, Daniel T; Lichtman, Judith H; Mohl, Stephanie; Sacco, Ralph L; Saver, Jeffrey L; Trogdon, Justin G
2013-08-01
Stroke is a leading cause of disability, cognitive impairment, and death in the United States and accounts for 1.7% of national health expenditures. Because the population is aging and the risk of stroke more than doubles for each successive decade after the age of 55 years, these costs are anticipated to rise dramatically. The objective of this report was to project future annual costs of care for stroke from 2012 to 2030 and discuss potential cost reduction strategies. The American Heart Association/American Stroke Association developed methodology to project the future costs of stroke-related care. Estimates excluded costs associated with other cardiovascular diseases (hypertension, coronary heart disease, and congestive heart failure). By 2030, 3.88% of the US population>18 years of age is projected to have had a stroke. Between 2012 and 2030, real (2010$) total direct annual stroke-related medical costs are expected to increase from $71.55 billion to $183.13 billion. Real indirect annual costs (attributable to lost productivity) are projected to rise from $33.65 billion to $56.54 billion over the same period. Overall, total annual costs of stroke are projected to increase to $240.67 billion by 2030, an increase of 129%. These projections suggest that the annual costs of stroke will increase substantially over the next 2 decades. Greater emphasis on implementing effective preventive, acute care, and rehabilitative services will have both medical and societal benefits.
Haemodynamic dose-response effects of intravenous nisoldipine in coronary artery disease.
Silke, B; Frais, M A; Muller, P; Verma, S P; Reynolds, G; Taylor, S H
1985-01-01
The circulatory consequences of slow-calcium channel blockade with a new dihydropyridine nisoldipine were evaluated at rest and during exercise-induced angina in 16 patients with angiographically proven coronary artery disease. In 10 patients resting cardiac stroke output (thermodilution) and pulmonary artery occluded pressure were determined following four intravenous nisoldipine injections (cumulative dosage of 1, 2, 4 and 8 micrograms kg-1). The exercise effects of nisoldipine were evaluated by comparing the effects of the 8 micrograms kg-1 cumulative dosage with a control exercise period at the same workload. At rest nisoldipine reduced systemic vascular resistance and mean arterial pressure, and increased heart rate, cardiac and stroke volume indices. During 4 min supine-bicycle exercise nisoldipine reduced systemic mean arterial pressure and vascular resistance; this resulted in augmented cardiac and stroke volume indices at an unchanged pulmonary artery occluded pressure. In six additional patients rest and exercise ejection fractions were measured using a nonimaging nuclear probe. Nisoldipine (4 micrograms kg-1) resulted in a small trend to increase left ventricular rest and exercise ejection fraction. These data demonstrated improved rest and exercise cardiac performance following nisoldipine in patients with severe coronary artery disease. PMID:4091998
Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight
NASA Technical Reports Server (NTRS)
Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi;
2002-01-01
Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts approximately 72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (+/- S.E.M.) stroke volume was lower (46 +/- 5 vs. 76 +/- 3 ml, P = 0.017) and heart rate was higher (93 +/- 1 vs. 74 +/- 4 beats min(-1), P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 +/- 256 vs. 1372 +/- 62 dynes s cm(-5), P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 +/- 4 vs. 17 +/- 2 bursts min(-1), P = 0.04) and tilted (46 +/- 4 vs. 38 +/- 3 bursts min(-1), P = 0.01) positions. A strong (r(2) = 0.91-1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal.
Eleid, Mackram F; Sorajja, Paul; Michelena, Hector I; Malouf, Joseph F; Scott, Christopher G; Pellikka, Patricia A
2013-10-15
Among patients with severe aortic stenosis (AS) and preserved ejection fraction, those with low gradient (LG) and reduced stroke volume may have an adverse prognosis. We investigated the prognostic impact of stroke volume using the recently proposed flow-gradient classification. We examined 1704 consecutive patients with severe AS (aortic valve area <1.0 cm(2)) and preserved ejection fraction (≥50%) using 2-dimensional and Doppler echocardiography. Patients were stratified by stroke volume index (<35 mL/m(2) [low flow, LF] versus ≥35 mL/m(2) [normal flow, NF]) and aortic gradient (<40 mm Hg [LG] versus ≥40 mm Hg [high gradient, HG]) into 4 groups: NF/HG, NF/LG, LF/HG, and LF/LG. NF/LG (n=352, 21%), was associated with favorable survival with medical management (2-year estimate, 82% versus 67% in NF/HG; P<0.0001). LF/LG severe AS (n=53, 3%) was characterized by lower ejection fraction, more prevalent atrial fibrillation and heart failure, reduced arterial compliance, and reduced survival (2-year estimate, 60% versus 82% in NF/HG; P<0.001). In multivariable analysis, the LF/LG pattern was the strongest predictor of mortality (hazard ratio, 3.26; 95% confidence interval, 1.71-6.22; P<0.001 versus NF/LG). Aortic valve replacement was associated with a 69% mortality reduction (hazard ratio, 0.31; 95% confidence interval, 0.25-0.39; P<0.0001) in LF/LG and NF/HG, with no survival benefit associated with aortic valve replacement in NF/LG and LF/HG. NF/LG severe AS with preserved ejection fraction exhibits favorable survival with medical management, and the impact of aortic valve replacement on survival was neutral. LF/LG severe AS is characterized by a high prevalence of atrial fibrillation, heart failure, and reduced survival, and aortic valve replacement was associated with improved survival. These findings have implications for the evaluation and subsequent management of AS severity.
The influence of emotional stress on Doppler-derived aortic peak velocity in boxer dogs.
Pradelli, D; Quintavalla, C; Crosta, M C; Mazzoni, L; Oliveira, P; Scotti, L; Brambilla, P; Bussadori, C
2014-01-01
Subaortic stenosis (SAS) is a common congenital heart disease in Boxers. Doppler-derived aortic peak velocity (AoPV) is a diagnostic criterion for the disease. To investigate the influence of emotional stress during echocardiographic examination on AoPV in normal and SAS-affected Boxers. To evaluate the effects of aortic root diameters on AoPV in normal Boxers. DOGS: Two hundred and fifteen normal and 19 SAS-affected Boxers. The AoPV was recorded at the beginning of echocardiographic examination (T0), and when the emotional stress of the dog was assumed to decrease based on behavioral parameters and heart rate (T1). AoPV0-AoPV1 was calculated. In normal dogs, stroke volume index was calculated at T0 and T1. Aortic root diameters were measured and their relationship with AoPV and AoPV0-AoPV1 was evaluated. In normal dogs, AoPV was higher at T0 (median, 1.95 m/s; range, 1.60-2.50 m/s) than at T1 (median, 1.76 m/s; range, 1.40-2.20 m/s; P < .0001; reduction 9.2%). The stroke volume index at T0 also was greater than at T1 (P < .0001). Weak negative correlations were detected between aortic root size and aortic velocities. In SAS-affected dogs, AoPV0 was higher than AoPV1 (P < .0001; reduction 7.3%). Aortic peak velocity was affected by emotional stress during echocardiographic examination both in SAS-affected and normal Boxers. In normal Boxers, aortic root size weakly affected AoPVs, but did not affect AoPV0-AoPV1. Stroke volume seems to play a major role in stress-related AoPV increases in normal Boxers. Emotional stress should be taken into account when screening for SAS in the Boxer breed. Copyright © 2014 by the American College of Veterinary Internal Medicine.
Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight
Levine, Benjamin D; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Zuckerman, Julie H; Diedrich, André; Biaggioni, Italo; Ray, Chester A; Smith, Michael L; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D; Buckey, Jay C; Cooke, William H; Baisch, Friedhelm J; Robertson, David; Eckberg, Dwain L; Blomqvist, C Gunnar
2002-01-01
Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts ∼72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (± s.e.m.) stroke volume was lower (46 ± 5 vs. 76 ± 3 ml, P = 0.017) and heart rate was higher (93 ± 1 vs. 74 ± 4 beats min−1, P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 ± 256 vs. 1372 ± 62 dynes s cm−5, P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 ± 4 vs. 17 ± 2 bursts min−1, P = 0.04) and tilted (46 ± 4 vs. 38 ± 3 bursts min−1, P = 0.01) positions. A strong (r2 = 0.91–1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal. PMID:11773340
Mean platelet volume: a potential biomarker of the risk and prognosis of heart disease.
Choi, Dong-Hyun; Kang, Seong-Ho; Song, Heesang
2016-11-01
Platelets are essential for progression of atherosclerotic lesions, plaque destabilization, and thrombosis. They secrete and express many substances that are crucial mediators of coagulation, inflammation, and atherosclerosis. Mean platelet volume (MPV) is a precise measure of platelet size, and is routinely reported during complete blood count analysis. Emerging evidence supports the use of MPV as a biomarker predicting the risk of ischemic stroke in patients with atrial fibrillation, and as a guide for prescription of anticoagulation and rhythm-control therapy. In addition, MPV may predict the clinical outcome of percutaneous coronary intervention (PCI) in patients with coronary artery disease and indicate whether additional adjunctive therapy is needed to improve clinical outcomes. This review focuses on the current evidence that MPV may be a biomarker of the risk and prognosis of common heart diseases, particularly atrial fibrillation and coronary artery disease treated via PCI.
Hernández-Pérez, María; Puig, Josep; Blasco, Gerard; Pérez de la Ossa, Natalia; Dorado, Laura; Dávalos, Antoni; Munuera, Josep
2016-02-01
Contrary to usual static vascular imaging techniques, contrast-enhanced dynamic magnetic resonance angiography (dMRA) enables dynamic study of cerebral vessels. We evaluated dMRA ability to assess arterial occlusion, cerebral hemodynamics, and collateral circulation in acute ischemic stroke. Twenty-five acute ischemic stroke patients with proximal anterior circulation occlusion underwent dMRA on a 3T scanner within 12 hours of symptoms onset. Diffusion weighted imaging, Tmax6 s lesion volumes and hypoperfusion intensity ratio as volume of Tmax>6 s/volume of Tmax>10 s were measured. Site and grade of occlusion (Thrombolysis in Myocardial Infarction criteria) were evaluated on time-of-flight MRA and dMRA. Leptomeningeal collaterality (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology [ASITN/SIR] Scale) and asymmetries in venous clearance were assessed exclusively on dMRA. Collateral filling was dichotomized into incomplete (ASITN/SIR 0-2) or complete (ASITN/SIR 3-4). On dMRA, site of occlusion was M1 in 21 patients, tandem internal carotid artery/M1 in 2 and tandem internal carotid artery/terminal internal carotid artery in 2 patients. Three tandem occlusions were not detected on time-of-flight-MRA. All patients had Thrombolysis in Myocardial Infarction 0 to 1 on time-of-flight-MRA, but three of them had Thrombolysis in Myocardial Infarction 2 on dMRA. Complete collateral filling (n=12, 48%) was associated with smaller diffusion weighted imaging lesion volume (P=0.039), smaller hypoperfused volume (P=0.018), and lower hypoperfusion intensity ratio (P=0.006). Patients with symmetrical clearance of transverse sinuses (52%) were more likely to have complete collateral filling (P=0.015). As a fast, direct, feasible, noninvasive, and reliable method to assess site of occlusion, collateral circulation and hemodynamic alterations, dMRA provides profound insights in acute stroke. © 2015 American Heart Association, Inc.
Batchelor, Connor; Pordeli, Pooneh; d'Esterre, Christopher D; Najm, Mohamed; Al-Ajlan, Fahad S; Boesen, Mari E; McDougall, Connor; Hur, Lisa; Fainardi, Enrico; Shankar, Jai Jai Shiva; Rubiera, Marta; Khaw, Alexander V; Hill, Michael D; Demchuk, Andrew M; Sajobi, Tolulope T; Goyal, Mayank; Lee, Ting-Yim; Aviv, Richard I; Menon, Bijoy K
2017-06-01
Intracerebral hemorrhage is a feared complication of intravenous alteplase therapy in patients with acute ischemic stroke. We explore the use of multimodal computed tomography in predicting this complication. All patients were administered intravenous alteplase with/without intra-arterial therapy. An age- and sex-matched case-control design with classic and conditional logistic regression techniques was chosen for analyses. Outcome was parenchymal hemorrhage on 24- to 48-hour imaging. Exposure variables were imaging (noncontrast computed tomography hypoattenuation degree, relative volume of very low cerebral blood volume, relative volume of cerebral blood flow ≤7 mL/min·per 100 g, relative volume of T max ≥16 s with all volumes standardized to z axis coverage, mean permeability surface area product values within T max ≥8 s volume, and mean permeability surface area product values within ipsilesional hemisphere) and clinical variables (NIHSS [National Institutes of Health Stroke Scale], onset to imaging time, baseline systolic blood pressure, blood glucose, serum creatinine, treatment type, and reperfusion status). One-hundred eighteen subjects (22 patients with parenchymal hemorrhage versus 96 without, median baseline NIHSS score of 15) were included in the final analysis. In multivariable regression, noncontrast computed tomography hypoattenuation grade ( P <0.006) and computerized tomography perfusion white matter relative volume of very low cerebral blood volume ( P =0.04) were the only significant variables associated with parenchymal hemorrhage on follow-up imaging (area under the curve, 0.73; 95% confidence interval, 0.63-0.83). Interrater reliability for noncontrast computed tomography hypoattenuation grade was moderate (κ=0.6). Baseline hypoattenuation on noncontrast computed tomography and very low cerebral blood volume on computerized tomography perfusion are associated with development of parenchymal hemorrhage in patients with acute ischemic stroke receiving intravenous alteplase. © 2017 American Heart Association, Inc.
Remote Measurements of Heart and Respiration Rates for Telemedicine
Qian, Yi; Tsien, Joe Z.
2013-01-01
Non-contact and low-cost measurements of heart and respiration rates are highly desirable for telemedicine. Here, we describe a novel technique to extract blood volume pulse and respiratory wave from a single channel images captured by a video camera for both day and night conditions. The principle of our technique is to uncover the temporal dynamics of heart beat and breathing rate through delay-coordinate transformation and independent component analysis-based deconstruction of the single channel images. Our method further achieves robust elimination of false positives via applying ratio-variation probability distributions filtering approaches. Moreover, it enables a much needed low-cost means for preventing sudden infant death syndrome in new born infants and detecting stroke and heart attack in elderly population in home environments. This noncontact-based method can also be applied to a variety of animal model organisms for biomedical research. PMID:24115996
Executive function, but not memory, associates with incident coronary heart disease and stroke.
Rostamian, Somayeh; van Buchem, Mark A; Westendorp, Rudi G J; Jukema, J Wouter; Mooijaart, Simon P; Sabayan, Behnam; de Craen, Anton J M
2015-09-01
To evaluate the association of performance in cognitive domains executive function and memory with incident coronary heart disease and stroke in older participants without dementia. We included 3,926 participants (mean age 75 years, 44% male) at risk for cardiovascular diseases from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER) with Mini-Mental State Examination score ≥24 points. Scores on the Stroop Color-Word Test (selective attention) and the Letter Digit Substitution Test (processing speed) were converted to Z scores and averaged into a composite executive function score. Likewise, scores of the Picture Learning Test (immediate and delayed memory) were transformed into a composite memory score. Associations of executive function and memory were longitudinally assessed with risk of coronary heart disease and stroke using multivariable Cox regression models. During 3.2 years of follow-up, incidence rates of coronary heart disease and stroke were 30.5 and 12.4 per 1,000 person-years, respectively. In multivariable models, participants in the lowest third of executive function, as compared to participants in the highest third, had 1.85-fold (95% confidence interval [CI] 1.39-2.45) higher risk of coronary heart disease and 1.51-fold (95% CI 0.99-2.30) higher risk of stroke. Participants in the lowest third of memory had no increased risk of coronary heart disease (hazard ratio 0.99, 95% CI 0.74-1.32) or stroke (hazard ratio 0.87, 95% CI 0.57-1.32). Lower executive function, but not memory, is associated with higher risk of coronary heart disease and stroke. Lower executive function, as an independent risk indicator, might better reflect brain vascular pathologies. © 2015 American Academy of Neurology.
Shimizu, Yukiko; Kodama, Kazunori; Nishi, Nobuo; Kasagi, Fumiyoshi; Suyama, Akihiko; Soda, Midori; Grant, Eric J; Sugiyama, Hiromi; Sakata, Ritsu; Moriwaki, Hiroko; Hayashi, Mikiko; Konda, Manami; Shore, Roy E
2010-01-14
To investigate the degree to which ionising radiation confers risk of mortality from heart disease and stroke. Prospective cohort study with more than 50 years of follow-up. Atomic bomb survivors in Hiroshima and Nagasaki, Japan. 86 611 Life Span Study cohort members with individually estimated radiation doses from 0 to >3 Gy (86% received <0.2 Gy). Mortality from stroke or heart disease as the underlying cause of death and dose-response relations with atomic bomb radiation. About 9600 participants died of stroke and 8400 died of heart disease between 1950 and 2003. For stroke, the estimated excess relative risk per gray was 9% (95% confidence interval 1% to 17%, P=0.02) on the basis of a linear dose-response model, but an indication of possible upward curvature suggested relatively little risk at low doses. For heart disease, the estimated excess relative risk per gray was 14% (6% to 23%, P<0.001); a linear model provided the best fit, suggesting excess risk even at lower doses. However, the dose-response effect over the restricted dose range of 0 to 0.5 Gy was not significant. Prospective data on smoking, alcohol intake, education, occupation, obesity, and diabetes had almost no impact on the radiation risk estimates for either stroke or heart disease, and misdiagnosis of cancers as circulatory diseases could not account for the associations seen. Doses above 0.5 Gy are associated with an elevated risk of both stroke and heart disease, but the degree of risk at lower doses is unclear. Stroke and heart disease together account for about one third as many radiation associated excess deaths as do cancers among atomic bomb survivors.
Prediction of Ischemic Heart Disease and Stroke in Survivors of Childhood Cancer.
Chow, Eric J; Chen, Yan; Hudson, Melissa M; Feijen, Elizabeth A M; Kremer, Leontien C; Border, William L; Green, Daniel M; Meacham, Lillian R; Mulrooney, Daniel A; Ness, Kirsten K; Oeffinger, Kevin C; Ronckers, Cécile M; Sklar, Charles A; Stovall, Marilyn; van der Pal, Helena J; van Dijk, Irma W E M; van Leeuwen, Flora E; Weathers, Rita E; Robison, Leslie L; Armstrong, Gregory T; Yasui, Yutaka
2018-01-01
Purpose We aimed to predict individual risk of ischemic heart disease and stroke in 5-year survivors of childhood cancer. Patients and Methods Participants in the Childhood Cancer Survivor Study (CCSS; n = 13,060) were observed through age 50 years for the development of ischemic heart disease and stroke. Siblings (n = 4,023) established the baseline population risk. Piecewise exponential models with backward selection estimated the relationships between potential predictors and each outcome. The St Jude Lifetime Cohort Study (n = 1,842) and the Emma Children's Hospital cohort (n = 1,362) were used to validate the CCSS models. Results Ischemic heart disease and stroke occurred in 265 and 295 CCSS participants, respectively. Risk scores based on a standard prediction model that included sex, chemotherapy, and radiotherapy (cranial, neck, and chest) exposures achieved an area under the curve and concordance statistic of 0.70 and 0.70 for ischemic heart disease and 0.63 and 0.66 for stroke, respectively. Validation cohort area under the curve and concordance statistics ranged from 0.66 to 0.67 for ischemic heart disease and 0.68 to 0.72 for stroke. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups. The cumulative incidences at age 50 years among CCSS low-risk groups were < 5%, compared with approximately 20% for high-risk groups ( P < .001); cumulative incidence was only 1% for siblings ( P < .001 v low-risk survivors). Conclusion Information available to clinicians soon after completion of childhood cancer therapy can predict individual risk for subsequent ischemic heart disease and stroke with reasonable accuracy and discrimination through age 50 years. These models provide a framework on which to base future screening strategies and interventions.
Forbang, Nketi I; Michos, Erin D; McClelland, Robyn L; Remigio-Baker, Rosemay A; Allison, Matthew A; Sandfort, Veit; Ix, Joachim H; Thomas, Isac; Rifkin, Dena E; Criqui, Michael H
2016-11-01
Abdominal aortic calcium (AAC) and coronary artery calcium (CAC) independently and similarly predict cardiovascular disease (CVD) events. The standard AAC and CAC score, the Agatston method, upweights for greater calcium density, thereby modeling higher calcium density as a CVD hazard. Computed tomography scans were used to measure AAC and CAC volume and density in a multiethnic cohort of community-dwelling individuals, and Cox proportional hazard was used to determine their independent association with incident coronary heart disease (CHD, defined as myocardial infarction, resuscitated cardiac arrest, or CHD death), cardiovascular disease (CVD, defined as CHD plus stroke and stroke death), and all-cause mortality. In 997 participants with Agatston AAC and CAC scores >0, the mean age was 66±9 years, and 58% were men. During an average follow-up of 9 years, there were 77 CHD, 118 CVD, and 169 all-cause mortality events. In mutually adjusted models, additionally adjusted for CVD risk factors, an increase in ln(AAC volume) per standard deviation was significantly associated with increased all-cause mortality (hazard ratio=1.20; 95% confidence interval, 1.08-1.33; P<0.01) and an increased ln(CAC volume) per standard deviation was significantly associated with CHD (hazard ratio=1.17; 95% confidence interval, 1.04-1.59; P=0.02) and CVD (hazard ratio=1.20; 95% confidence interval, 1.05-1.36; P<0.01). In contrast, both AAC and CAC density were not significantly associated with CVD events. The Agatston method of upweighting calcium scores for greater density may be inappropriate for CVD risk prediction in both the abdominal aorta and coronary arteries. © 2016 American Heart Association, Inc.
Powers, William J; Rabinstein, Alejandro A; Ackerson, Teri; Adeoye, Opeolu M; Bambakidis, Nicholas C; Becker, Kyra; Biller, José; Brown, Michael; Demaerschalk, Bart M; Hoh, Brian; Jauch, Edward C; Kidwell, Chelsea S; Leslie-Mazwi, Thabele M; Ovbiagele, Bruce; Scott, Phillip A; Sheth, Kevin N; Southerland, Andrew M; Summers, Deborah V; Tirschwell, David L
2018-03-01
The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates. Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format. These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke. © 2018 American Heart Association, Inc.
The Minnesota Heart Disease and Stroke Prevention Plan 2011-2020: a progress report.
Shanedling, Stanton; Schardin, Sueling
2013-05-01
The Minnesota Heart Disease and Stroke Prevention Plan 2011-2020 was developed to organize the efforts of individuals, health care organizations and communities around prevention, treatment and management of heart disease and stroke. This article provides a brief update on the state's efforts, pointing out that Minnesota has made the most progress in terms of disease management thanks in part to the widespread use of electronic health records and requirements for quality reporting.
Deep-Diving California Sea Lions: Are they Pushing their Physiological Limit
2013-09-30
backpack digital recorders to measure blood oxygen depletion, heart rate, and flipper stroke rate in dives of California sea lions during maternal...relationship between changes in heart rate to blood O2 profiles, and 3) documentation of flipper stroke rate profiles during shallow and deep dives, and...assessment of the relationship of stroke rate to both changes in heart rate and changes in blood O2 profiles. APPROACH Objective 1: In order to
Gohdes, Dorothy; Fogle, Crystelle C.; Tadios, Fawn; Doore, Velva; Bell, Doreen S.; Harwell, Todd S.; Helgerson, Steven D.
2013-01-01
Introduction National initiatives to improve the recognition of heart attack and stroke warning signs have encouraged symptomatic people to seek early treatment, but few have shown significant effects in rural American Indian (AI) communities. Methods During 2009 and 2010, the Montana Cardiovascular Health Program, in collaboration with 2 tribal health departments, developed and conducted culturally specific public awareness campaigns for signs and symptoms of heart attack and stroke via local media. Telephone surveys were conducted before and after each campaign to evaluate the effectiveness of the campaigns. Results Knowledge of 3 or more heart attack warning signs and symptoms increased significantly on 1 reservation from 35% at baseline to 47% postcampaign. On the second reservation, recognition of 2 or more stroke signs and symptoms increased from 62% at baseline to 75% postcampaign, and the level of awareness remained at 73% approximately 4 months after the high-intensity campaign advertisements ended. Intent to call 9-1-1 did not increase in the heart attack campaign but did improve in the stroke campaign for specific symptoms. Recall of media campaigns on both reservations increased significantly from baseline to postcampaign for both media outlets (ie, radio and newspaper). Conclusion Carefully designed, culturally specific campaigns may help eliminate disparities in the recognition of heart attack and stroke warning signs in AI communities. PMID:23680509
Oser, Carrie S; Gohdes, Dorothy; Fogle, Crystelle C; Tadios, Fawn; Doore, Velva; Bell, Doreen S; Harwell, Todd S; Helgerson, Steven D
2013-05-16
National initiatives to improve the recognition of heart attack and stroke warning signs have encouraged symptomatic people to seek early treatment, but few have shown significant effects in rural American Indian (AI) communities. During 2009 and 2010, the Montana Cardiovascular Health Program, in collaboration with 2 tribal health departments, developed and conducted culturally specific public awareness campaigns for signs and symptoms of heart attack and stroke via local media. Telephone surveys were conducted before and after each campaign to evaluate the effectiveness of the campaigns. Knowledge of 3 or more heart attack warning signs and symptoms increased significantly on 1 reservation from 35% at baseline to 47% postcampaign. On the second reservation, recognition of 2 or more stroke signs and symptoms increased from 62% at baseline to 75% postcampaign, and the level of awareness remained at 73% approximately 4 months after the high-intensity campaign advertisements ended. Intent to call 9-1-1 did not increase in the heart attack campaign but did improve in the stroke campaign for specific symptoms. Recall of media campaigns on both reservations increased significantly from baseline to postcampaign for both media outlets (ie, radio and newspaper). Carefully designed, culturally specific campaigns may help eliminate disparities in the recognition of heart attack and stroke warning signs in AI communities.
Code of Federal Regulations, 2013 CFR
2013-07-01
... includes heart attack and stroke. Child-parent relationship means a relationship between a public safety... the heart attack or stroke about. Designation on file—A designation of beneficiary under the Act, at... with its personnel or similar records pertaining to him. Direct and proximate result of a heart attack...
Code of Federal Regulations, 2014 CFR
2014-07-01
... includes heart attack and stroke. Child-parent relationship means a relationship between a public safety... the heart attack or stroke about. Designation on file—A designation of beneficiary under the Act, at... with its personnel or similar records pertaining to him. Direct and proximate result of a heart attack...
Code of Federal Regulations, 2012 CFR
2012-07-01
... includes heart attack and stroke. Child-parent relationship means a relationship between a public safety... the heart attack or stroke about. Designation on file—A designation of beneficiary under the Act, at... with its personnel or similar records pertaining to him. Direct and proximate result of a heart attack...
Detection of low-volume blood loss: compensatory reserve versus traditional vital signs.
Stewart, Camille L; Mulligan, Jane; Grudic, Greg Z; Convertino, Victor A; Moulton, Steven L
2014-12-01
Humans are able to compensate for low-volume blood loss with minimal change in traditional vital signs. We hypothesized that a novel algorithm, which analyzes photoplethysmogram (PPG) wave forms to continuously estimate compensatory reserve would provide greater sensitivity and specificity to detect low-volume blood loss compared with traditional vital signs. The compensatory reserve index (CRI) is a measure of the reserve remaining to compensate for reduced central blood volume, where a CRI of 1 represents supine normovolemia and 0 represents the circulating blood volume at which hemodynamic decompensation occurs; values between 1 and 0 indicate the proportion of reserve remaining. Subjects underwent voluntary donation of 1 U (approximately 450 mL) of blood. Demographic and continuous noninvasive vital sign wave form data were collected, including PPG, heart rate, systolic blood pressure, cardiac output, and stroke volume. PPG wave forms were later processed by the algorithm to estimate CRI values. Data were collected from 244 healthy subjects (79 males and 165 females), with a mean (SD) age of 40.1 (14.2) years and mean (SD) body mass index of 25.6 (4.7). After blood donation, CRI significantly decreased in 92% (α = 0.05; 95% confidence interval [CI], 88-95%) of the subjects. With the use of a threshold decrease in CRI of 0.05 or greater for the detection of 1 U of blood loss, the receiver operating characteristic area under the curve was 0.90, with a sensitivity of 0.84 and specificity of 0.86. In comparison, systolic blood pressure (52%; 95% CI, 45-59%), heart rate (65%; 95% CI, 58-72%), cardiac output (47%; 95% CI, 40-54%), and stroke volume (74%; 95% CI, 67-80%) changed in fewer subjects, had significantly lower receiver operating characteristic area under the curve values, and significantly lower specificities for detecting the same volume of blood loss. Consistent with our hypothesis, CRI detected low-volume blood loss with significantly greater specificity than other traditional physiologic measures. These findings warrant further evaluation of the CRI algorithm in actual trauma settings. Diagnostic study, level II.
Kajantie, Eero; Räikkönen, Katri; Henriksson, Markus; Leskinen, Jukka T; Forsén, Tom; Heinonen, Kati; Pesonen, Anu-Katriina; Osmond, Clive; Barker, David J P; Eriksson, Johan G
2012-01-01
Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices) and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. 281 men (10.1%) had experienced a coronary heart disease event and 131 (4.7%) a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD) lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46). Stroke was predicted by a low visuospatial reasoning score, the corresponding hazard ratio being 1.23 (95% confidence interval 1.04 to 1.46), adjusted for year and age at testing. Adjusted in addition for the two other scores, the hazard ratio was 1.40 (1.10 to 1.79). This hazard ratio was little affected by adjustment for socioeconomic status in childhood and adult life, whereas the same adjustments attenuated the associations between intellectual ability and coronary heart disease. The associations with stroke were also unchanged when adjusted for systolic blood pressure at 20 years and reimbursement for adult antihypertensive medication. Stroke is predicted by low visuospatial reasoning scores in relation to scores in the two other subtests. This association may be mediated by common underlying causes such as impaired brain development, rather than by mechanisms associated with risk factors shared by stroke and coronary heart disease, such as socio-economic status, hypertension and atherosclerosis.
2014-01-01
Summary Background Body-mass index (BMI) and diabetes have increased worldwide, whereas global average blood pressure and cholesterol have decreased or remained unchanged in the past three decades. We quantified how much of the effects of BMI on coronary heart disease and stroke are mediated through blood pressure, cholesterol, and glucose, and how much is independent of these factors. Methods We pooled data from 97 prospective cohort studies that collectively enrolled 1·8 million participants between 1948 and 2005, and that included 57 161 coronary heart disease and 31 093 stroke events. For each cohort we excluded participants who were younger than 18 years, had a BMI of lower than 20 kg/m2, or who had a history of coronary heart disease or stroke. We estimated the hazard ratio (HR) of BMI on coronary heart disease and stroke with and without adjustment for all possible combinations of blood pressure, cholesterol, and glucose. We pooled HRs with a random-effects model and calculated the attenuation of excess risk after adjustment for mediators. Findings The HR for each 5 kg/m2 higher BMI was 1·27 (95% CI 1·23–1·31) for coronary heart disease and 1·18 (1·14–1·22) for stroke after adjustment for confounders. Additional adjustment for the three metabolic risk factors reduced the HRs to 1·15 (1·12–1·18) for coronary heart disease and 1·04 (1·01–1·08) for stroke, suggesting that 46% (95% CI 42–50) of the excess risk of BMI for coronary heart disease and 76% (65–91) for stroke is mediated by these factors. Blood pressure was the most important mediator, accounting for 31% (28–35) of the excess risk for coronary heart disease and 65% (56–75) for stroke. The percentage excess risks mediated by these three mediators did not differ significantly between Asian and western cohorts (North America, western Europe, Australia, and New Zealand). Both overweight (BMI ≥25 to <30 kg/m2) and obesity (BMI ≥30 kg/m2) were associated with a significantly increased risk of coronary heart disease and stroke, compared with normal weight (BMI ≥20 to <25 kg/m2), with 50% (44–58) of the excess risk of overweight and 44% (41–48) of the excess risk of obesity for coronary heart disease mediated by the selected three mediators. The percentages for stroke were 98% (69–155) for overweight and 69% (64–77) for obesity. Interpretation Interventions that reduce high blood pressure, cholesterol, and glucose might address about half of excess risk of coronary heart disease and three-quarters of excess risk of stroke associated with high BMI. Maintenance of optimum bodyweight is needed for the full benefits. Funding US National Institute of Health, UK Medical Research Council, National Institute for Health Research Comprehensive Biomedical Research Centre at Imperial College Healthcare NHS Trust, Lown Scholars in Residence Program on cardiovascular disease prevention, and Harvard Global Health Institute Doctoral Research Grant. PMID:24269108
Lu, Yuan; Hajifathalian, Kaveh; Ezzati, Majid; Woodward, Mark; Rimm, Eric B; Danaei, Goodarz
2014-03-15
Body-mass index (BMI) and diabetes have increased worldwide, whereas global average blood pressure and cholesterol have decreased or remained unchanged in the past three decades. We quantified how much of the effects of BMI on coronary heart disease and stroke are mediated through blood pressure, cholesterol, and glucose, and how much is independent of these factors. We pooled data from 97 prospective cohort studies that collectively enrolled 1·8 million participants between 1948 and 2005, and that included 57,161 coronary heart disease and 31,093 stroke events. For each cohort we excluded participants who were younger than 18 years, had a BMI of lower than 20 kg/m(2), or who had a history of coronary heart disease or stroke. We estimated the hazard ratio (HR) of BMI on coronary heart disease and stroke with and without adjustment for all possible combinations of blood pressure, cholesterol, and glucose. We pooled HRs with a random-effects model and calculated the attenuation of excess risk after adjustment for mediators. The HR for each 5 kg/m(2) higher BMI was 1·27 (95% CI 1·23-1·31) for coronary heart disease and 1·18 (1·14-1·22) for stroke after adjustment for confounders. Additional adjustment for the three metabolic risk factors reduced the HRs to 1·15 (1·12-1·18) for coronary heart disease and 1·04 (1·01-1·08) for stroke, suggesting that 46% (95% CI 42-50) of the excess risk of BMI for coronary heart disease and 76% (65-91) for stroke is mediated by these factors. Blood pressure was the most important mediator, accounting for 31% (28-35) of the excess risk for coronary heart disease and 65% (56-75) for stroke. The percentage excess risks mediated by these three mediators did not differ significantly between Asian and western cohorts (North America, western Europe, Australia, and New Zealand). Both overweight (BMI ≥25 to <30 kg/m(2)) and obesity (BMI ≥30 kg/m(2)) were associated with a significantly increased risk of coronary heart disease and stroke, compared with normal weight (BMI ≥20 to <25 kg/m(2)), with 50% (44-58) of the excess risk of overweight and 44% (41-48) of the excess risk of obesity for coronary heart disease mediated by the selected three mediators. The percentages for stroke were 98% (69-155) for overweight and 69% (64-77) for obesity. Interventions that reduce high blood pressure, cholesterol, and glucose might address about half of excess risk of coronary heart disease and three-quarters of excess risk of stroke associated with high BMI. Maintenance of optimum bodyweight is needed for the full benefits. US National Institute of Health, UK Medical Research Council, National Institute for Health Research Comprehensive Biomedical Research Centre at Imperial College Healthcare NHS Trust, Lown Scholars in Residence Program on cardiovascular disease prevention, and Harvard Global Health Institute Doctoral Research Grant. Copyright © 2014 Elsevier Ltd. All rights reserved.
Preeclampsia and Future Cardiovascular Health: A Systematic Review and Meta-Analysis.
Wu, Pensée; Haththotuwa, Randula; Kwok, Chun Shing; Babu, Aswin; Kotronias, Rafail A; Rushton, Claire; Zaman, Azfar; Fryer, Anthony A; Kadam, Umesh; Chew-Graham, Carolyn A; Mamas, Mamas A
2017-02-01
Preeclampsia is a pregnancy-specific disorder resulting in hypertension and multiorgan dysfunction. There is growing evidence that these effects persist after pregnancy. We aimed to systematically evaluate and quantify the evidence on the relationship between preeclampsia and the future risk of cardiovascular diseases. We studied the future risk of heart failure, coronary heart disease, composite cardiovascular disease, death because of coronary heart or cardiovascular disease, stroke, and stroke death after preeclampsia. A systematic search of MEDLINE and EMBASE was performed to identify relevant studies. We used random-effects meta-analysis to determine the risk. Twenty-two studies were identified with >6.4 million women including >258 000 women with preeclampsia. Meta-analysis of studies that adjusted for potential confounders demonstrated that preeclampsia was independently associated with an increased risk of future heart failure (risk ratio [RR], 4.19; 95% confidence interval [CI], 2.09-8.38), coronary heart disease (RR, 2.50; 95% CI, 1.43-4.37), cardiovascular disease death (RR, 2.21; 95% CI, 1.83-2.66), and stroke (RR, 1.81; 95% CI, 1.29-2.55). Sensitivity analyses showed that preeclampsia continued to be associated with an increased risk of future coronary heart disease, heart failure, and stroke after adjusting for age (RR, 3.89; 95% CI, 1.83-8.26), body mass index (RR, 3.16; 95% CI, 1.41-7.07), and diabetes mellitus (RR, 4.19; 95% CI, 2.09-8.38). Preeclampsia is associated with a 4-fold increase in future incident heart failure and a 2-fold increased risk in coronary heart disease, stroke, and death because of coronary heart or cardiovascular disease. Our study highlights the importance of lifelong monitoring of cardiovascular risk factors in women with a history of preeclampsia. © 2017 American Heart Association, Inc.
Andersson, Charlotte; Preis, Sarah R; Beiser, Alexa; DeCarli, Charles; Wollert, Kai C; Wang, Thomas J; Januzzi, James L; Vasan, Ramachandran S; Seshadri, Sudha
2015-09-01
Growth differentiation factor-15 (GDF-15) and soluble (s)ST2 are markers of cardiac and vascular stress. We investigated the associations between circulating concentrations of these biomarkers and incident stroke and subclinical vascular brain injury in a sample from the Framingham Offspring cohort. We followed 3374 stroke- and dementia-free individuals (mean age, 59.0±9.7 years; 53% women) attending the Framingham Offspring sixth examination cycle 11.8±3.0 years for incident stroke. A subsample of 2463 individuals underwent brain magnetic resonance imaging and neuropsychological testing ≈4.0±1.7 years after the sixth examination. After adjustment for traditional cardiovascular risk factors, B-type natriuretic peptide, high-sensitivity C-reactive protein, and urine albumin levels, higher stress biomarker levels were associated cross-sectionally with lower brain volumes (β coefficients for intracranial volume comparing fourth [Q4] versus first biomarker [Q1] quartiles: -0.71% for GDF-15; P=0.002 and 0.47% for sST2; P=0.02) and worse performance on the visual reproduction test (β coefficients for Q4 versus Q1: -0.62 for GDF-15; P=0.009 and -0.40 for sST2; P=0.04). Higher GDF-15 concentrations were also associated with greater log-transformed white-matter hyperintensity volumes (β for Q4 versus Q1=0.19; P=0.01). Prospectively, a total of 203 (6%) individuals developed incident stroke/transient ischemic attack during follow-up. After multivariable adjustment, sST2 remained significantly associated with stroke/transient ischemic attack, hazard ratio for Q4 versus Q1 of 1.76, 95% confidence interval of 1.06 to 2.92, and P=0.03. Circulating GDF-15 and sST2 are associated with subclinical brain injury and cognitive impairment. Higher sST2 concentrations are also associated with incident stroke, suggesting potential links between cardiac stress biomarkers and brain injury. © 2015 American Heart Association, Inc.
Ng, Kwan L; Gibson, Ellen M; Hubbard, Robert; Yang, Juemin; Caffo, Brian; O'Brien, Richard J; Krakauer, John W; Zeiler, Steven R
2015-10-01
Data from both humans and animal models suggest that most recovery from motor impairment after stroke occurs in a sensitive period that lasts only weeks and is mediated, in part, by an increased responsiveness to training. Here, we used a mouse model of focal cortical stroke to test 2 hypotheses. First, we investigated whether responsiveness to training decreases over time after stroke. Second, we tested whether fluoxetine, which can influence synaptic plasticity and stroke recovery, can prolong the period over which large training-related gains can be elicited after stroke. Mice were trained to perform a skilled prehension task to an asymptotic level of performance after which they underwent stroke induction in the caudal forelimb area. The mice were then retrained after a 1- or 7-day delay with and without fluoxetine. Recovery of prehension after a caudal forelimb area stroke was complete if training was initiated 1 day after stroke but incomplete if it was delayed by 7 days. In contrast, if fluoxetine was administered at 24 hours after stroke, then complete recovery of prehension was observed even with the 7-day training delay. Fluoxetine seemed to mediate its beneficial effect by reducing inhibitory interneuron expression in intact premotor cortex rather than through effects on infarct volume or cell death. There is a gradient of diminishing responsiveness to motor training over the first week after stroke. Fluoxetine can overcome this gradient and maintain maximal levels of responsiveness to training even 7 days after stroke. © 2015 American Heart Association, Inc.
Denoising and 4D visualization of OCT images
Gargesha, Madhusudhana; Jenkins, Michael W.; Rollins, Andrew M.; Wilson, David L.
2009-01-01
We are using Optical Coherence Tomography (OCT) to image structure and function of the developing embryonic heart in avian models. Fast OCT imaging produces very large 3D (2D + time) and 4D (3D volumes + time) data sets, which greatly challenge ones ability to visualize results. Noise in OCT images poses additional challenges. We created an algorithm with a quick, data set specific optimization for reduction of both shot and speckle noise and applied it to 3D visualization and image segmentation in OCT. When compared to baseline algorithms (median, Wiener, orthogonal wavelet, basic non-orthogonal wavelet), a panel of experts judged the new algorithm to give much improved volume renderings concerning both noise and 3D visualization. Specifically, the algorithm provided a better visualization of the myocardial and endocardial surfaces, and the interaction of the embryonic heart tube with surrounding tissue. Quantitative evaluation using an image quality figure of merit also indicated superiority of the new algorithm. Noise reduction aided semi-automatic 2D image segmentation, as quantitatively evaluated using a contour distance measure with respect to an expert segmented contour. In conclusion, the noise reduction algorithm should be quite useful for visualization and quantitative measurements (e.g., heart volume, stroke volume, contraction velocity, etc.) in OCT embryo images. With its semi-automatic, data set specific optimization, we believe that the algorithm can be applied to OCT images from other applications. PMID:18679509
Fox, Kim; Bousser, Marie-Germaine; Amarenco, Pierre; Chamorro, Angel; Fisher, Marc; Ford, Ian; Hennerici, Michael G; Mattle, Heinrich P; Rothwell, Peter M
2013-10-09
Elevated resting heart rate is known to be detrimental to morbidity and mortality in cardiovascular disease, though its effect in patients with ischemic stroke is unclear. We analyzed the effect of baseline resting heart rate on myocardial infarction (MI) in patients with a recent noncardioembolic cerebral ischemic event participating in PERFORM. We compared fatal or nonfatal MI using adjusted Cox proportional hazards models for PERFORM patients with baseline heart rate <70 bpm (n=8178) or ≥70 bpm (n=10,802). In addition, heart rate was analyzed as a continuous variable. Other cerebrovascular and cardiovascular outcomes were also explored. Heart rate ≥70 bpm was associated with increased relative risk for fatal or nonfatal MI (HR 1.32, 95% CI 1.03-1.69, P=0.029). For every 5-bpm increase in heart rate, there was an increase in relative risk for fatal and nonfatal MI (11.3%, P=0.0002). Heart rate ≥70 bpm was also associated with increased relative risk for a composite of fatal or nonfatal ischemic stroke, fatal or nonfatal MI, or other vascular death (excluding hemorrhagic death) (P<0001); vascular death (P<0001); all-cause mortality (P<0001); and fatal or nonfatal stroke (P=0.04). For every 5-bpm increase in heart rate, there were increases in relative risk for fatal or nonfatal ischemic stroke, fatal or nonfatal MI, or other vascular death (4.7%, P<0.0001), vascular death (11.0%, P<0.0001), all-cause mortality (8.0%, P<0.0001), and fatal and nonfatal stroke (2.4%, P=0.057). Elevated heart rate ≥70 bpm places patients with a noncardioembolic cerebral ischemic event at increased risk for MI. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Preventing High Blood Pressure
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Cholesterol Facts and Statistics
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... high blood pressure, staying on your medicines is critical to prevent heart attacks, strokes, kidney disease and ... high blood pressure, staying on your medicines is critical to prevent heart attacks, strokes, kidney disease and ...
Rich, S; Wix, H L; Shapiro, E P
1981-09-01
It has been generally accepted that enhanced blood flow during closed-chest CPR is generated from compression of the heart between the sternum and the spine. To visualize the heart during closed-chest massage, we performed two-dimensional echocardiography (2DE) during resuscitation efforts in four patients who had cardiac arrest. 2DE analysis showed that (1) the LV internal dimensions did not change appreciably with chest compression; (2) the mitral and aortic valves were open simultaneously during the compression phase; (3) blood flow into the right heart, as evidenced by saline bubble contrast, occurred during the relaxation phase; and (4) compression of the right ventricle and LA occurred in varying amounts in all patients. We conclude that stroke volume from the heart during CPR does not result from compression of the LV. Rather, CPR-induced improved cardiocirculatory dynamics appear to be principally the result of changes in intrathoracic pressure created by sternal compression.
Renú, Arturo; Laredo, Carlos; Lopez-Rueda, Antonio; Llull, Laura; Tudela, Raúl; San-Roman, Luis; Urra, Xabier; Blasco, Jordi; Macho, Juan; Oleaga, Laura; Chamorro, Angel; Amaro, Sergio
2017-03-01
Less than half of acute ischemic stroke patients treated with mechanical thrombectomy obtain permanent clinical benefits. Consequently, there is an urgent need to identify mechanisms implicated in the limited efficacy of early reperfusion. We evaluated the predictors and prognostic significance of vessel wall permeability impairment and its association with blood-cerebrospinal fluid barrier (BCSFB) disruption after acute stroke treated with thrombectomy. A prospective cohort of acute stroke patients treated with stent retrievers was analyzed. Vessel wall permeability impairment was identified as gadolinium vessel wall enhancement (GVE) in a 24- to 48-hour follow-up contrast-enhanced magnetic resonance imaging, and severe BCSFB disruption was defined as subarachnoid hemorrhage or gadolinium sulcal enhancement (present across >10 slices). Infarct volume was evaluated in follow-up magnetic resonance imaging, and clinical outcome was evaluated with the modified Rankin Scale at day 90. A total of 60 patients (median National Institutes of Health Stroke Scale score, 18) were analyzed, of whom 28 (47%) received intravenous alteplase before mechanical thrombectomy. Overall, 34 (57%) patients had GVE and 27 (45%) had severe BCSFB disruption. GVE was significantly associated with alteplase use before thrombectomy and with more stent retriever passes, along with the presence of severe BCSFB disruption. GVE was associated with poor clinical outcome, and both GVE and severe BCSFB disruption were associated with increased final infarct volume. These findings may support the clinical relevance of direct vessel damage and BCSFB disruption after acute stroke and reinforce the need for further improvements in reperfusion strategies. Further validation in larger cohorts of patients is warranted. © 2017 American Heart Association, Inc.
Kim, Seo Hyun; Saver, Jeffrey L
2015-01-01
Body temperature (BT) is an important physiological factor in acute ischemic stroke. However, the relationship of initial BT to stroke severity and degree of benefit from thrombolytic therapy has been delineated incompletely. We analyzed the public data set of the 2 National Institute of Neurological Disorders and Stroke Tissue-Type Plasminogen Activator (tPA) stroke trials, comparing patients with lower (<37.0°C) and higher (≥37.0°C) presenting BT. Among 595 patients (297 placebo and 298 tPA treated) with documented initial BT, 77.1% had initial BT <37.0°C and 22.9% ≥37.0°C. Patients with higher initial BT had lower baseline stroke severity in both tPA-treated patients (the National Institute of Health Stroke Scale median, 11 versus 15; P=0.05) and placebo-treated patients (median, 13 versus 16; P<0.01). Patients with higher initial BT also had lower infarction volume on computed tomography at 3 months in both tPA-treated patients (median, 9.6 versus 16.7 cm(3); P=0.08) and placebo-treated patients (median, 13.1 versus 28.1 cm(3); P=0.02), but no clinical outcome differences. Analysis of lytic treatment effect found no heterogeneity in the degree of tPA benefit in both higher and lower BT groups (≥37.0°C: odds ratio for the modified Rankin Scale 0-1 outcome, 2.55; 95% confidence interval, 1.05-6.21 and <37.0°C: odds ratio, 2.30; 95% confidence interval, 1.38-3.84; heterogeneity P=0.83). In patients with hyperacute stroke, higher presenting temperatures are associated with less severe neurological deficits and reduced final infarct volumes. Presenting temperature does not modify the benefit of tPA on 3-month favorable outcome. © 2014 American Heart Association, Inc.
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WISEWOMAN: Frequently Asked Questions
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Kaminski, Grzegorz; Dziuk, Mirosław; Szczepanek-Parulska, Ewelina; Zybek-Kocik, Ariadna; Ruchala, Marek
2016-08-01
Subclinical hyperthyroidism (sHT) was found to be associated with elevated heart rate, blood pressure and increased risk of extrasystoles. However, the full clinical relevance of morphological and functional implications of sHT on the cardiovascular system is still a matter of debate. The aim of the study was to prospectively assess the influence of endogenous sHT on exercise capacity and cardiac function during workout with the use of exercise electrocardiography (ExECG) and perfusion scintigraphy. The studied group consisted of 44 consecutively recruited patients diagnosed with sHT. In all patients, ExECG, followed by post-exercise myocardial perfusion imaging, was performed. Both ExECG and scintigraphy were performed twice-in the state of sHT and after euthyroidism was restored. An average time period of exercise test was significantly longer in the state of euthyroidism than in sHT. An average oxygen consumption during exercise test was also higher after euthyroidism was achieved when compared to sHT. The end-diastolic and end-systolic volume indexes, stroke volume index and cardiac index were significantly larger in patients with sHT if compared values achieved after euthyroidism restoration. Stroke volume index was negatively correlated with TSH, and positively with free thyroid hormones values in the state of sHT, before euthyroidism was achieved. Cardiac index was positively correlated with free thyroid hormones levels. The obtained results indicate worse physical capacity in subjects with sHT and improvement of several parameters assessed during ExECG and perfusion scintiscan after therapy. Observed changes might reflect the mechanism of the deleterious effect exerted by sHT on the heart.
Continuous cardiac output measurement - Aspects of Doppler frequency analysis
NASA Technical Reports Server (NTRS)
Mackay, R. S.; Hechtman, H. B.
1975-01-01
From the suprasternal notch blood flow velocity in the aorta can be measured non-invasively by a Doppler probe. Integration over systole after frequency analysis gives a measure of stroke volume if a separate diameter observation is incorporated. Frequency analysis by a zero crossing counter or by a set of parallel phaselock loops was less effective than a set of bandpass filters. Observations on dogs, baboons and humans before and after exercise or surgery suggest the indications to be useful. Application to judging heart failure by the effect of introducing a volume load is indicated. Changes in output also are measured in freely moving subjects.
Poulter, Christopher; Stewart, Michelle; Fitzpatrick, Cliona; Keech, Wendy; Stavreski, Bill; Grenfell, Robert
2014-06-01
General practice requires systems to deal with patients presenting with urgent needs. BeAWARE was developed to support non-clinical staff to promptly identify patients with symptoms of heart attack or stroke. Data were collected from May 2012 to December 2012 on participants completing the BeAWARE learning module, including pre- and post-assessments on knowledge, confidence and intended action. From May 2012 to December 2012, 1865 participants completed the module. There were significant increases in recall of heart attack and stroke symptoms among non-clinical participants, including chest tightness (23.4-48.7%, P DISCUSSION: BeAWARE fulfils a practice gap in patient safety by improving non-clinical staff's knowledge, confidence and intended action in response to patients presenting with heart attack or stroke warning signs.
Lutfiyya, May Nawal; Bardales, Ricardo; Bales, Robert; Aguero, Carlos; Brady, Shelly; Tobar, Adriana; McGrath, Cynthia; Zaiser, Julia; Lipsky, Martin S
2010-10-01
There is evidence that Hispanic men are a high risk group for treatment delay for both heart attack and stroke. More targeted research is needed to elucidate this specific population's knowledge of warning signs for these acute events. This study sought to describe within-group disparities in Hispanic men's knowledge of heart attack and stroke symptomology. Multivariate techniques were used to analyze a multi-year Behavioral Risk Factor Surveillance Heart and Stroke module database. The data were cross-sectional and focused on health risk factors and behaviors. The research participants were U.S. male Hispanic adults aged 18-99. The main outcome measure for the study was heart attack and stroke symptom knowledge score. Multivariate logistic regression analysis yielded that Hispanic men aged >or=18 years who earned low scores on the composite heart attack and stroke knowledge questions (range 0-8 points) were more likely to: have less than a high school education, have deferred medical care because of cost, not have an identified health care provider, and be uninsured. There were significant within-group differences. Targeting educational efforts toward older (>or=55 years) Hispanic men with less than high school education, those who do not have an identified health care provider or health insurance, and who defer health care because of cost could be ways to improve the outcome of acute vascular events among the U.S. Hispanic adult male population.
Thelandersson, Anneli; Nellgård, Bengt; Ricksten, Sven-Erik; Cider, Åsa
2016-12-01
Physiotherapy is an important part of treatment after severe brain injuries and stroke, but its effect on intracranial and systemic hemodynamics is minimally investigated. Therefore, the aim of this study was to assess the effects of an early bedside cycle exercise on intracranial and systemic hemodynamics in critically ill patients when admitted to a neurointensive care unit (NICU). Twenty critically ill patients suffering from brain injuries or stroke were included in this study performed in the NICU at Sahlgrenska University Hospital. One early implemented exercise session was performed using a bedside cycle ergometer for 20 min. Intracranial and hemodynamic variables were measured two times before, three times during, and two times after the bedside cycling exercise. Analyzed variables were intracranial pressure (ICP), cerebral perfusion pressure (CPP), mean arterial blood pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO 2 ), cardiac output (CO), stroke volume (SV), and stroke volume variation (SVV). The cycling intervention was conducted within 7 ± 5 days after admission to the NICU. Cycle exercise increased MAP (p = 0.029) and SV (p = 0.003) significantly. After exercise CO, SV, MAP, and CPP decreased significantly, while no changes in HR, SVV, SpO 2 , or ICP were noted when compared to values obtained during exercise. There were no differences in data obtained before versus after exercise. Early implemented exercise with a bedside cycle ergometer, for patients with severe brain injuries or stroke when admitted to a NICU, is considered to be a clinically safe procedure.
Sylaja, P N; Pandian, Jeyaraj Durai; Kaul, Subhash; Srivastava, M V Padma; Khurana, Dheeraj; Schwamm, Lee H; Kesav, Praveen; Arora, Deepti; Pannu, Aman; Thankachan, Tijy K; Singhal, Aneesh B
2018-01-01
The Indo-US Collaborative Stroke Project was designed to characterize ischemic stroke across 5 high-volume academic tertiary hospitals in India. From January 2012 to August 2014, research coordinators and physician coinvestigators prospectively collected data on 2066 patients with ischemic stroke admitted <2 weeks after onset. Investigator training and supervision and data monitoring were conducted by the US site (Massachusetts General Hospital, Boston). The mean age was 58.3±14.7 years, 67.2% men. The median admission National Institutes of Health Stroke Scale score was 10 (interquartile range, 5-15) and 24.5% had National Institutes of Health Stroke Scale ≥16. Hypertension (60.8%), diabetes mellitus (35.7%), and tobacco use (32.2%, including bidi/smokeless tobacco) were common risk factors. Only 4% had atrial fibrillation. All patients underwent computed tomography or magnetic resonance imaging; 81% had cerebrovascular imaging. Stroke etiologic subtypes were large artery (29.9%), cardiac (24.9%), small artery (14.2%), other definite (3.4%), and undetermined (27.6%, including 6.7% with incomplete evaluation). Intravenous or intra-arterial thrombolysis was administered in 13%. In-hospital mortality was 7.9%, and 48% achieved modified Rankin Scale score 0 to 2 at 90 days. On multivariate analysis, diabetes mellitus predicted poor 3-month outcome and younger age, lower admission National Institutes of Health Stroke Scale and small-artery etiology predicted excellent 3-month outcome. These comprehensive and novel clinical imaging data will prove useful in refining stroke guidelines and advancing stroke care in India. © 2017 American Heart Association, Inc.
Heart failure: a weak link in CHA2 DS2 -VASc.
Friberg, Leif; Lund, Lars H
2018-06-01
In atrial fibrillation, stroke risk is assessed by the CHA 2 DS 2 -VASc score. Heart failure is included in CHA 2 DS 2 -VASc, but the rationale is uncertain. Our objective was to test if heart failure is a risk factor for stroke, independent of other risk factors in CHA 2 DS 2 -VASc. We studied 300 839 patients with atrial fibrillation in the Swedish Patient Register 2005-11. Three definitions of heart failure were used in order to assess the robustness of the results. In the main analysis, heart failure was defined by a hospital discharge diagnosis of heart failure as first or second diagnosis and a filled prescription of a diuretic within 3 months before index + 30 days. The second definition counted first or second discharge diagnoses <1 year before index + 30 days and the third definition any heart failure diagnosis in open or hospital care before index + 30 days. Associations with outcomes were assessed with multivariable Cox analyses. Patients with heart failure were older (80.5 vs. 74.0 years, P < 0.001) and had higher CHA 2 DS 2 -VASc score (4.4 vs. 2.7, P < 0.001). The 1 year incidence of ischaemic stroke without warfarin was 4.4% with heart failure and 3.1% without. Adjustment for the cofactors in CHA 2 DS 2 -VASc eradicated the difference in stroke risk between patients with and without heart failure (hazard ratio 1.01 with 95% confidence interval 0.96-1.05). The area under the receiver operating characteristic curve for CHA 2 DS 2 -VASc was not improved by points for heart failure. A clinical diagnosis of heart failure was not an independent risk factor for stroke in patients with atrial fibrillation, which may have implications for anticoagulation management. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.
Towfighi, Amytis; Ovbiagele, Bruce; El Husseini, Nada; Hackett, Maree L; Jorge, Ricardo E; Kissela, Brett M; Mitchell, Pamela H; Skolarus, Lesli E; Whooley, Mary A; Williams, Linda S
2017-02-01
Poststroke depression (PSD) is common, affecting approximately one third of stroke survivors at any one time after stroke. Individuals with PSD are at a higher risk for suboptimal recovery, recurrent vascular events, poor quality of life, and mortality. Although PSD is prevalent, uncertainty remains regarding predisposing risk factors and optimal strategies for prevention and treatment. This is the first scientific statement from the American Heart Association on the topic of PSD. Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association's Manuscript Oversight Committee. Members were assigned topics relevant to their areas of expertise and reviewed appropriate literature, references to published clinical and epidemiology studies, clinical and public health guidelines, authoritative statements, and expert opinion. This multispecialty statement provides a comprehensive review of the current evidence and gaps in current knowledge of the epidemiology, pathophysiology, outcomes, management, and prevention of PSD, and provides implications for clinical practice. © 2016 American Heart Association, Inc.
Walters, Arthur S; Rye, David B
2009-05-01
Evidence is reviewed documenting an intimate relationship among restless legs syndrome (RLS) / periodic limb movements in sleep (PLMS) and hypertension and cardiovascular and cerebrovascular disease. Sympathetic overactivity is associated with RLS/PLMS, as manifested by increased pulse rate and blood pressure coincident with PLMS. Causality is far from definitive. Mechanisms are explored as to how RLS/PLMS may lead to high blood pressure, heart disease, and stroke: (a) the sympathetic hyperactivity associated with RLS/PLMS may lead to daytime hypertension that in turn leads to heart disease and stroke; (b) in the absence of daytime hypertension, this sympathetic hyperactivity may predispose to heart disease and stroke either directly or indirectly via atherosclerotic plaque formation and rupture; and (c) comorbidities associated with RLS/PLMS, such as renal failure, diabetes, iron deficiency, and insomnia, may predispose to heart disease and stroke. One theoretical cause for sympathetic hyperactivity is insufficient All diencephalospinal dopaminergic neuron inhibition of sympathetic preganglionic neurons residing in the intermediolateral cell columns of the spinal cord. We cannot exclude the possibility that peripheral vascular, cardiovascular, and cerebrovascular disease may also contribute to RLS/PLMS, and mechanisms for these possibilities are also discussed.
Ethnicity and Onset of Cardiovascular Disease: A CALIBER Study
2017-06-07
Abdominal Aortic Aneurysm; Coronary Heart Disease; Sudden Cardiac Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest
Khafaji, Hadi A R; Sulaiman, Kadhim; Singh, Rajvir; AlHabib, Khalid F; Asaad, Nidal; Alsheikh-Ali, Alawi; Al-Jarallah, Mohammed; Bulbanat, Bassam; AlMahmeed, Wael; Ridha, Mustafa; Bazargani, Nooshin; Amin, Haitham; Al-Motarreb, Ahmed; AlFaleh, Hussam; Elasfar, Abdelfatah; Panduranga, Prashanth; Al Suwaidi, Jassim
2015-01-01
Objectives The purpose of this study is to report the prevalence, clinical characteristics, precipitating factors, management and outcome of patients with prior stroke hospitalised with acute heart failure (HF). Design Retrospective analysis of prospectively collected data. Setting Data were derived from Gulf CARE (Gulf aCute heArt failuRe rEgistry), a prospective multicentre study of consecutive patients hospitalised with acute HF in 2012 in seven Middle Eastern countries and analysed according to the presence or absence of prior stroke; demographics, management and outcomes were compared. Participants A total of 5005 patients with HF. Outcome measures In-hospital and 1-year outcome. Results The prevalence of prior stroke in patients with HF was 8.1%. Patients with stroke with HF were more likely to be admitted under the care of internists rather than cardiologists. When compared with patients without stroke, patients with stroke were more likely to be older and to have diabetes mellitus, hypertension, atrial fibrillation, hyperlipidaemia, chronic kidney disease, ischaemic heart disease, peripheral arterial disease and left ventricular dysfunction (p=0.001 for all). Patients with stroke were less likely to be smokers (0.003). There were no significant differences in terms of precipitating risk factors for HF hospitalisation between the two groups. Patients with stroke with HF had a longer hospital stay (mean±SD days; 11±14 vs 9±13, p=0.03), higher risk of recurrent strokes and 1-year mortality rates (32.7% vs 23.2%, p=0.001). Multivariate logistic regression analysis showed that stroke is an independent predictor of in-hospital and 1-year mortality. Conclusions This observational study reports high prevalence of prior stroke in patients hospitalised with HF. Internists rather than cardiologists were the predominant caregivers in this high-risk group. Patients with stroke had higher risk of in-hospital recurrent strokes and long-term mortality rates. Trial registration number NCT01467973. PMID:25908674
Clinical review: Positive end-expiratory pressure and cardiac output
Luecke, Thomas; Pelosi, Paolo
2005-01-01
In patients with acute lung injury, high levels of positive end-expiratory pressure (PEEP) may be necessary to maintain or restore oxygenation, despite the fact that 'aggressive' mechanical ventilation can markedly affect cardiac function in a complex and often unpredictable fashion. As heart rate usually does not change with PEEP, the entire fall in cardiac output is a consequence of a reduction in left ventricular stroke volume (SV). PEEP-induced changes in cardiac output are analyzed, therefore, in terms of changes in SV and its determinants (preload, afterload, contractility and ventricular compliance). Mechanical ventilation with PEEP, like any other active or passive ventilatory maneuver, primarily affects cardiac function by changing lung volume and intrathoracic pressure. In order to describe the direct cardiocirculatory consequences of respiratory failure necessitating mechanical ventilation and PEEP, this review will focus on the effects of changes in lung volume, factors controlling venous return, the diastolic interactions between the ventricles and the effects of intrathoracic pressure on cardiac function, specifically left ventricular function. Finally, the hemodynamic consequences of PEEP in patients with heart failure, chronic obstructive pulmonary disease and acute respiratory distress syndrome are discussed. PMID:16356246
Comparison of Perfusion CT Software to Predict the Final Infarct Volume After Thrombectomy.
Austein, Friederike; Riedel, Christian; Kerby, Tina; Meyne, Johannes; Binder, Andreas; Lindner, Thomas; Huhndorf, Monika; Wodarg, Fritz; Jansen, Olav
2016-09-01
Computed tomographic perfusion represents an interesting physiological imaging modality to select patients for reperfusion therapy in acute ischemic stroke. The purpose of our study was to determine the accuracy of different commercial perfusion CT software packages (Philips (A), Siemens (B), and RAPID (C)) to predict the final infarct volume (FIV) after mechanical thrombectomy. Single-institutional computed tomographic perfusion data from 147 mechanically recanalized acute ischemic stroke patients were postprocessed. Ischemic core and FIV were compared about thrombolysis in cerebral infarction (TICI) score and time interval to reperfusion. FIV was measured at follow-up imaging between days 1 and 8 after stroke. In 118 successfully recanalized patients (TICI 2b/3), a moderately to strongly positive correlation was observed between ischemic core and FIV. The highest accuracy and best correlation are shown in early and fully recanalized patients (Pearson r for A=0.42, B=0.64, and C=0.83; P<0.001). Bland-Altman plots and boxplots demonstrate smaller ranges in package C than in A and B. Significant differences were found between the packages about over- and underestimation of the ischemic core. Package A, compared with B and C, estimated more than twice as many patients with a malignant stroke profile (P<0.001). Package C best predicted hypoperfusion volume in nonsuccessfully recanalized patients. Our study demonstrates best accuracy and approximation between the results of a fully automated software (RAPID) and FIV, especially in early and fully recanalized patients. Furthermore, this software package overestimated the FIV to a significantly lower degree and estimated a malignant mismatch profile less often than other software. © 2016 American Heart Association, Inc.
Smith, Eric E; Saposnik, Gustavo; Biessels, Geert Jan; Doubal, Fergus N; Fornage, Myriam; Gorelick, Philip B; Greenberg, Steven M; Higashida, Randall T; Kasner, Scott E; Seshadri, Sudha
2017-02-01
Two decades of epidemiological research shows that silent cerebrovascular disease is common and is associated with future risk for stroke and dementia. It is the most common incidental finding on brain scans. To summarize evidence on the diagnosis and management of silent cerebrovascular disease to prevent stroke, the Stroke Council of the American Heart Association convened a writing committee to evaluate existing evidence, to discuss clinical considerations, and to offer suggestions for future research on stroke prevention in patients with 3 cardinal manifestations of silent cerebrovascular disease: silent brain infarcts, magnetic resonance imaging white matter hyperintensities of presumed vascular origin, and cerebral microbleeds. The writing committee found strong evidence that silent cerebrovascular disease is a common problem of aging and that silent brain infarcts and white matter hyperintensities are associated with future symptomatic stroke risk independently of other vascular risk factors. In patients with cerebral microbleeds, there was evidence of a modestly increased risk of symptomatic intracranial hemorrhage in patients treated with thrombolysis for acute ischemic stroke but little prospective evidence on the risk of symptomatic hemorrhage in patients on anticoagulation. There were no randomized controlled trials targeted specifically to participants with silent cerebrovascular disease to prevent stroke. Primary stroke prevention is indicated in patients with silent brain infarcts, white matter hyperintensities, or microbleeds. Adoption of standard terms and definitions for silent cerebrovascular disease, as provided by prior American Heart Association/American Stroke Association statements and by a consensus group, may facilitate diagnosis and communication of findings from radiologists to clinicians. © 2016 American Heart Association, Inc.
Foraker, Randi E; Greiner, Melissa; Sims, Mario; Tucker, Katherine L; Towfighi, Amytis; Bidulescu, Aurelian; Shoben, Abigail B; Smith, Sakima; Talegawkar, Sameera; Blackshear, Chad; Wang, Wei; Hardy, Natalie Chantelle; O'Brien, Emily
2016-07-01
Evidence from existing cohort studies supports the prediction of incident coronary heart disease and stroke using 10-year cardiovascular disease (CVD) risk scores and the American Heart Association/American Stroke Association's cardiovascular health (CVH) metric. We included all Jackson Heart Study participants with complete scoring information at the baseline study visit (2000-2004) who had no history of stroke (n = 4,140). We used Kaplan-Meier methods to calculate the cumulative incidence of stroke and used Cox models to estimate hazard ratios and 95% CIs for stroke according to CVD risk and CVH score. We compared the discrimination of the 2 models according to the Harrell c index and plotted predicted vs observed stroke risk calibration plots for each of the 2 models. The median age of the African American participants was 54.5 years, and 65% were female. The cumulative incidence of stroke increased across worsening categories of CVD risk and CVH. A 1-unit increase in CVD risk increased the hazard of stroke (1.07, 1.06-1.08), whereas each 1-unit increase in CVH corresponded to a decreased hazard of stroke (0.76, 0.69-0.83). As evidenced by the c statistics, the CVH model was less discriminating than the CVD risk model (0.59 [0.55-0.64] vs 0.79 [0.76-0.83]). Both scores were associated with incident stroke in a dose-response fashion; however, the CVD risk model was more discriminating than the CVH model. The CVH score may still be preferable for its simplicity in application to broad patient populations and public health efforts. Copyright © 2016 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Convertino, Victor A.
2005-01-01
There is little evidence obtained from space flight to support the notion that occurrence of cardiac dysrhythmias, impaired cardiac and vascular function, and manifestation of asymptomatic cardiovascular disease represent serious risks during space flight. Therefore, the development of orthostatic hypotension and instability immediately after return from spaceflight probably reflect the most significant operational risks associated with the cardiovascular system of astronauts. Significant reductions in stroke volume and lower reserve for increasing peripheral vascular resistance contribute to ineffective maintenance of systemic arterial blood pressure during standing after spaceflight despite compensatory elevations in heart rate. The primary mechanism underlying reduced stroke volume appears to be a reduction in preload associated with less circulating blood volume while inadequate peripheral vasoconstriction may be caused partly by hyporeactivity of receptors that control arterial smooth muscle function. A focus for development of future countermeasures for hemodynamic responses to central hypovolemia includes the potential application of pharmacological agents that specifically target and restore blood volume (e.g., fludrocortisone, electrolyte-containing beverages) and reserve for vasoconstriction (e.g., midodrine, vasopressin). Based on systematic evaluations, acute physical exercise designed to elicit maximal effort or inspiratory resistance have shown promise as successful countermeasures that provide protection against development of orthostatic hypotension and intolerance without potential risks and side effects associated with specific pharmacological interventions.
NASA Technical Reports Server (NTRS)
Evans, J. M.; Stenger, M. B.; Ferguson, C. R.; Ribiero, L. C.; Zhang, Q.; Moore, F. B.; Serrador, J.; Smith, J. D.; Knapp, C. F.
2014-01-01
We recently determined that a short exposure to artificial gravity (AG) improved the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned subjects. We now seek to determine the mechanisms of that improvement in these hypovolemic men and women. Methods. We determined the orthostatic tolerance limit (OTL) of 9 men and 8 women following a 90 min exposure to AG compared to 90 min of head down bed rest (HDBR). In both cases (21 days apart), subjects were made hypovolemic (low salt diet plus 20 mg intravenous furosemide). Orthostatic tolerance was determined from a combination of head up tilt and increasing lower body negative pressure until presyncope. Mean values and correlations with OTL were determined for heart rate, blood pressure, stroke volume, cardiac output and peripheral resistance (Finometer), cerebral artery blood velocity (DWL), partial pressure of carbon dioxide (Novametrics) and body segmental impedance (UFI THRIM) were measured during supine baseline, during OTL to presyncope and during supine recovery Results. Orthostatic tolerance of these hypovolemic subjects was significantly greater on the day of AG exposure than on the HDBR day. Regression of OTL on these variables identified significant relationships on the HDBR day that were not evident on the AG day: resting TPR correlated positively while resting cerebral flow correlated negatively with OTL. On both days, women's resting stroke volume correlated positively with orthostatic tolerance. Higher group mean values of stroke volume and cerebral artery flow and lower values of blood pressure, peripheral vascular and cerebrovascular resistance both at control and during OTL testing were observed on the AG day. Even though regression of OTL on resting stroke volume was significant only in women, presyncopal stroke volume reached the same level on each day of study for both men and women while the OTL test lasted 30% longer in men and 22% longer in women. Cerebral artery flow appeared to follow stroke volume and absolute values of cerebral flow did not correlate with the development of presyncope. Women responded to AG exposure with elevated cerebral flow at resting control and throughout the OTL test, implying a loss of autoregulation in deconditioned (hypovolemic) women following AG exposure. Conclusions. Before countermeasures to space flight cardiovascular deconditioning are established, gender differences in cardiovascular responses to orthostatic stress, in general, and to orthostatic stress following exposure to artificial gravity, in particular, need to be determined. Since, in both men and women, a single, acute bout of AG exposure improved orthostatic tolerance, the feasibility of short exposures to AG during longer spaceflights or prior to entry into a gravity (Earth or Mars) environment, should be explored. Given the known beneficial effects of AG on other organ systems, the present study indicates that the positive effects of AG on cardiac stroke volume make AG a likely candidate for maintaining cardiovascular conditioning.
A protocol to study ex vivo mouse working heart at human-like heart rate.
Feng, Han-Zhong; Jin, Jian-Ping
2018-01-01
Genetically modified mice are widely used as experimental models to study human heart function and diseases. However, the fast rate of normal mouse heart at 400-600bpm limits its capacity of assessing kinetic parameters that are important for the physiology and pathophysiology of human heart that beats at a much slower rate (75-180bpm). To extend the value of mouse models, we established a protocol to study ex vivo mouse working hearts at a human-like heart rate. In the presence of 300μM lidocaine to lower pacemaker and conductive activities and prevent arrhythmia, a stable rate of 120-130bpm at 37°C is achieved for ex vivo mouse working hearts. The negative effects of decreased heart rate on force-frequency dependence and lidocaine as a myocardial depressant on intracellular calcium can be compensated by using a higher but still physiological level of calcium (2.75mM) in the perfusion media. Multiple parameters were studied to compare the function at the human-like heart rate with that of ex vivo mouse working hearts at the standard rate of 480bpm. The results showed that the conditions for slower heart rate in the presence of 300μM lidocaine did not have depressing effect on left ventricular pressure development, systolic and diastolic velocities and stroke volume with maintained positive inotropic and lusitropic responses to β-adrenergic stimulation. Compared with that at 480bpm, the human-like heart rate increased ventricular filling and end diastolic volume with enhanced Frank-Starling responses. Coronary perfusion was increased from longer relaxation time and interval between beats whereas cardiac efficiency was significantly improved. Although the intrinsic differences between mouse and human heart remain, this methodology for ex vivo mouse hearts to work at human-like heart rate extends the value of using genetically modified mouse models to study cardiac function and human heart diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.
Dose-dependent heart rate reducing effect of nizatidine, a histamine H2-receptor antagonist.
Hinrichsen, H; Halabi, A; Fuhrmann, G; Kirch, W
1993-01-01
1. Twelve healthy subjects were treated in a randomised placebo-controlled crossover study with placebo, 150 mg, 300 mg, and 600 mg nizatidine, 100 mg pirenzepine, and 300 mg nizatidine plus 100 mg pirenzepine for 1 week each. 2. On the seventh treatment day, heart rate, blood pressure, systolic time intervals, impedance cardiographic and Doppler ultrasound variables were measured. 3. Stroke volume and blood pressure were not altered by nizatidine and/or pirenzepine. By contrast, heart rate and cardiac output significantly (P < 0.05) decreased in a dose-dependent manner 1.5 and 3 h after administration of 300 and 600 mg nizatidine. Treatment with 150 mg nizatidine led to similar though non-significant trends. 4. While a slightly insignificant rise in heart rate was detected with pirenzepine alone, heart rate and cardiac output remained unchanged upon combined nizatidine and pirenzepine treatment as compared with placebo and baseline values. 5. In conclusion, nizatidine reduced heart rate and cardiac output in a dose-dependent manner, whereas this negative chronotropic effect was counteracted by concurrent administration of the anti-cholinergic drug pirenzepine. PMID:8099802
Jauch, Edward C; Saver, Jeffrey L; Adams, Harold P; Bruno, Askiel; Connors, J J Buddy; Demaerschalk, Bart M; Khatri, Pooja; McMullan, Paul W; Qureshi, Adnan I; Rosenfield, Kenneth; Scott, Phillip A; Summers, Debbie R; Wang, David Z; Wintermark, Max; Yonas, Howard
2013-03-01
The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates. Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm. The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.
Kissela, B; Broderick, J; Woo, D; Kothari, R; Miller, R; Khoury, J; Brott, T; Pancioli, A; Jauch, E; Gebel, J; Shukla, R; Alwell, K; Tomsick, T
2001-06-01
The volume of ischemic stroke on CT scans has been studied in a standardized fashion in acute stroke therapy trials with median volumes between 10.5 to 55 cm(3). The volume of first-ever ischemic stroke in the population is not known. The first phase of the population-based Greater Cincinnati/Northern Kentucky Stroke Study identified all ischemic strokes occurring in blacks in the greater Cincinnati region between January and June of 1993. The patients in this phase of the study who had a first-ever ischemic clinical stroke were identified, and the volume of ischemic stroke was measured. There were 257 verified clinical cases of ischemic stroke, of which 181 had a first-ever ischemic infarct. Imaging was available for 150 of these patients, and 79 had an infarct on the CT or MRI study that was definitely or possibly related to the clinical symptoms. For these patients, volumetric measurements were performed by means of the modified ellipsoid method. The median volume of first-ever ischemic stroke for the 79 patients was 2.5 cm(3) (interquartile range, 0.5 to 8.8 cm(3)). There was a significant relation between location of lesion and infarct size (P<0.001) and between volume and mechanism of stroke (P=0.001). The volume of first-ever ischemic stroke among blacks in our population-based study is smaller than has been previously reported in acute stroke therapy trials. The large proportion of small, mild strokes in blacks may be an important reason for the low percentage of patients who meet the inclusion criteria for tissue plasminogen activator. Further study is necessary to see if these results are generalizable to a multiracial population.
Sheerah, Haytham A; Eshak, Ehab S; Cui, Renzhe; Imano, Hironori; Iso, Hiroyasu; Tamakoshi, Akiko
2018-02-01
There is growing evidence about the importance of vitamin D for cardiovascular health. Therefore, we examined the relationship between dietary vitamin D intake and risk of mortality from stroke and coronary heart disease in Japanese population. A prospective study encompassing 58 646 healthy Japanese adults (23 099 men and 35 547 women) aged of 40 to 79 years in whom dietary vitamin D intake was determined via a self-administered food frequency questionnaire. The median follow-up period was 19.3 years (1989-2009). The hazard ratios and 95% confidence intervals of mortality were calculated using categories of vitamin D intake. During 965 970 person-years of follow-up, 1514 stroke and 702 coronary heart disease deaths were documented. Vitamin D intake was inversely associated with risk of mortality from total stroke especially intraparenchymal hemorrhage but not from coronary heart disease; the multivariable hazard ratios (95% confidence intervals) for the highest (≥440 IU/d) versus lowest (<110 IU/D) categories of vitamin D intake were 0.70 (0.54-0.91; P for trend=0.04) for total stroke and 0.66 (0.46-0.96; P for trend=0.04) for intraparenchymal hemorrhage. Dietary vitamin D intake seems to be inversely associated with mortality from stroke. © 2018 American Heart Association, Inc.
Simning, Adam; Seplaki, Christopher L; Conwell, Yeates
2018-01-01
The objective of the study is to examine whether the risk of having clinically significant depressive symptoms following a heart attack or stroke varies by the presence of a close social contact. The National Health and Aging Trends Study is a nationally representative longitudinal survey of US Medicare beneficiaries aged 65 and older initiated in 2011. A total of 5643 older adults had information on social contacts at baseline and depressive symptoms at the 1-year follow-up interview. The two-item Patient Health Questionnaire identified clinically significant depressive symptoms. Interview questions examined social contacts and the presence of self-reported heart attack or stroke during the year of follow-up. A total of 297 older adults reported experiencing a heart attack and/or stroke between their baseline and follow-up interviews. In regression analyses accounting for sociodemographics, baseline depressive symptoms, medical comorbidity, and activities of daily living impairment, older adults with no close social contacts had increased odds of depressive symptoms at follow-up after experiencing a heart attack or stroke, while those with close social contacts had increased odds of depressive symptoms at follow-up after experiencing a stroke, but not a heart attack. Older adults have increased odds of having depressive symptoms following a self-reported stroke, but only those with no close social contacts had increased odds of depressive symptoms following a heart attack. Social networks may play a role in the mechanisms underlying depression among older adults experiencing certain acute health events. Future work exploring the potential causal relationships suggested here, if confirmed, could inform interventions to alleviate or prevent depression among at risk older adults. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Haines, David E; Wong, Wilson; Canby, Robert; Jewell, Coty; Houmsse, Mahmoud; Pederson, David; Sugeng, Lissa; Porterfield, John; Kottam, Anil; Pearce, John; Valvano, Jon; Michalek, Joel; Trevino, Aron; Sagar, Sandeep; Feldman, Marc D
2017-10-01
There is increasing evidence that using frequent invasive measures of pressure in patients with heart failure results in improved outcomes compared to traditional measures. Admittance, a measure of volume derived from preexisting defibrillation leads, is proposed as a new technique to monitor cardiac hemodynamics in patients with an implantable defibrillator. The purpose of this study was to evaluate the accuracy of a new ventricular volume sensor (VVS, CardioVol) compared with 3-dimenssional echocardiography (echo) in patients with an implantable defibrillator. Twenty-two patients referred for generator replacement had their defibrillation lead attached to VVS to determine the level of agreement to a volume measurement standard (echo). Two opposite hemodynamic challenges were sequentially applied to the heart (overdrive pacing and dobutamine administration) to determine whether real changes in hemodynamics could be reliably and repeatedly assessed with VVS. Equivalence of end-diastolic volume (EDV) and stroke volume (SV) determined by both methods was also assessed. EDV and SV were compared using VVS and echo. VVS tracked expected physiologic trends. EDV was modulated -10% by overdrive pacing (14 mL). SV was modulated -13.7% during overdrive pacing (-6 mL) and increased over baseline +14.6% (+8 mL) with dobutamine. VVS and echo mean EDVs were found statistically equivalent, with margin of equivalence 13.8 mL (P <.05). Likewise, mean SVs were found statistically equivalent with margin of equivalence 15.8 mL (P <.05). VVS provides an accurate method for ventricular volume assessment using chronically implanted defibrillator leads and is statistically equivalent to echo determination of mean EDV and SV. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Lopez, Lorna M; Hill, W David; Harris, Sarah E; Valdes Hernandez, Maria; Munoz Maniega, Susana; Bastin, Mark E; Bailey, Emma; Smith, Colin; McBride, Martin; McClure, John; Graham, Delyth; Dominiczak, Anna; Yang, Qiong; Fornage, Myriam; Ikram, M Arfan; Debette, Stephanie; Launer, Lenore; Bis, Joshua C; Schmidt, Reinhold; Seshadri, Sudha; Porteous, David J; Starr, John; Deary, Ian J; Wardlaw, Joanna M
2015-02-01
White matter hyperintensities (WMH) of presumed vascular origin increase the risk of stroke and dementia. Despite strong WMH heritability, few gene associations have been identified. Relevant experimental models may be informative. We tested the associations between genes that were differentially expressed in brains of young spontaneously hypertensive stroke-prone rats and human WMH (using volume and visual score) in 621 subjects from the Lothian Birth Cohort 1936 (LBC1936). We then attempted replication in 9361 subjects from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE). We also tested the subjects from LBC1936 for previous genome-wide WMH associations found in subjects from CHARGE. Of 126 spontaneously hypertensive stroke-prone rat genes, 10 were nominally associated with WMH volume or score in subjects from LBC1936, of which 5 (AFP, ALB, GNAI1, RBM8a, and MRPL18) were associated with both WMH volume and score (P<0.05); 2 of the 10 (XPNPEP1, P=6.7×10(-5); FARP1, P=0.024) plus another spontaneously hypertensive stroke-prone rat gene (USMG5, P=0.00014), on chromosomes 10, 13, and 10 respectively, were associated with WMH in subjects from CHARGE. Gene set enrichment showed significant associations for downregulated spontaneously hypertensive stroke-prone rat genes with WMH in humans. In subjects from LBC1936, we replicated CHARGE's genome-wide WMH associations on chromosomes 17 (TRIM65 and TRIM47) and, for the first time, 1 (PMF1). Despite not passing multiple testing thresholds individually, these genes collectively are relevant to known WMH associations, proposed WMH mechanisms, or dementia: associations with Alzheimer's disease, late-life depression, ATP production, osmotic regulation, neurodevelopmental abnormalities, and cognitive impairment. If replicated further, they suggest a multifactorial nature for WMH and argue for more consideration of vascular contributions to dementia. © 2015 The Authors.
Hung, Ching-Hsia; Chang, Nen-Chung; Cheng, Bor-Chih; Lin, Mao-Tsun
2005-05-01
Heat shock protein (HSP) 72 expression protects against arterial hypotension in rat heatstroke. HSP72 can also be induced in multiple organs, including hearts from rats with endurance exercise. We validated the hypothesis that progressive exercise preconditioning may confer cardiovascular protection during heatstroke by inducing the overexpression of HSP72 in multiple organs. To deal with the matter, we assessed the effects of heatstroke on mean arterial pressure, heart rate, cardiac output, stroke volume, total peripheral vascular resistance, colonic temperature, blood gases, and serum or tissue levels of tumor necrosis factor-alpha (TNF-alpha) in urethane-anesthetized rats pretreated without or with progressive exercise training for 1, 2, or 3 weeks. In addition, HSP72 expression in multiple organs was determined in different groups of animals. Heatstroke was induced by exposing the rats to a high blanket temperature (43 degrees C); the moment at which mean arterial pressure decreased from the peak value was taken as the time of heatstroke onset. Previous exercise training for 3 weeks, but not 1 or 2 weeks, conferred significant protection against hyperthermia, arterial hypotension, decreased cardiac output, decreased stroke volume, decreased peripheral vascular resistance, and increased levels of serum or tissue TNF-alpha during heatstroke and correlated with overexpression of HSP72 in multiple organs, including heart, liver, and adrenal gland. However, 10 days after 3 weeks of progressive exercise training, when HSP72 expression in multiple organs returned to basal values, the beneficial effects exerted by 3 weeks of exercise training were no longer observed. These results strongly suggest that HSP72 preconditioning with progressive exercise training protects against hyperthermia, circulatory shock, and TNF-alpha overproduction during heatstroke.
The webinar was requested by the Justus-Warren Heart Disease and Stroke Prevention Task Force. From their website, “The task force was established in 1995 in North Carolina to provide statewide leadership for the prevention and management of cardiovascular disease. Meetings are...
Kulick, Erin R; Wellenius, Gregory A; Kaufman, Joel D; DeRosa, Janet T; Kinney, Patrick L; Cheung, Ying Kuen; Wright, Clinton B; Sacco, Ralph L; Elkind, Mitchell S
2017-07-01
Long-term exposure to ambient air pollution is associated with higher risk of cardiovascular disease and stroke. We hypothesized that long-term exposure to air pollution would be associated with magnetic resonance imaging markers of subclinical cerebrovascular disease. Participants were 1075 stroke-free individuals aged ≥50 years drawn from the magnetic resonance imaging subcohort of the Northern Manhattan Study who had lived at the same residence for at least 2 years before magnetic resonance imaging. Cross-sectional associations between ambient air pollution and subclinical cerebrovascular disease were analyzed. We found an association between distance to roadway, a proxy for residential exposure to traffic pollution, and white matter hyperintensity volume; however, after adjusting for risk factors, this relationship was no longer present. All other associations between pollutant measures and white matter hyperintensity volume were null. There was no clear association between exposure to air pollutants and subclinical brain infarcts or total cerebral brain volume. We found no evidence that long-term exposure to ambient air pollution is independently associated with subclinical cerebrovascular disease in an urban population-based cohort. © 2017 American Heart Association, Inc.
Increased pulmonary transit times in asymptomatic dogs with mitral regurgitation.
Lord, Peter; Eriksson, Anders; Häggström, Jens; Järvinen, Anna-Kaisa; Kvart, Clarence; Hansson, Kerstin; Maripuu, Enn; Mäkelä, Olli
2003-01-01
Pulmonary transit time (PTT) normalized to heart rate (nPTT) is a measure of the pulmonary blood volume (PBV) to stroke volume ratio (PBV/SV). It is an index of cardiac performance. To determine the effect of compensated mitral regurgitation (CMR) and decompensated mitral regurgitation (DMR) caused by valvular endocardiosis on the index nPTT, we measured nPTT by first-pass radionuclide angiocardiography and ECG in 13 normal dogs, 18 dogs with CMR, and 13 dogs with DMR. PTT was measured as time between onset of appearance of activity at the pulmonary trunk and the left atrium. In the normal dogs, the relationship between PTT and mean R-R interval (mRR) was PTT = 4.08 x mRR + 0.15 (R2 = 0.71). Normal nPTT was 4.4 +/- 0.6 (SD) (range. 3.6-5.3). in CMR, 6.3 +/- 1.6 (SD) (range, 4.0-9.7). and in DMR, 11.9 +/- 3.4 (SD) (range, 8.0-18.8). The differences among all groups were significant. Heart rates were 110 +/- 22 bpm in normal dogs, 111 +/- 20 in dogs with CMR, and 144 +/- 18 in dogs with DMR (P < .001 for difference between DMR group and normal and CMR groups). Increased nPTT in CMR indicates preclinical heart pump dysfunction. Heart rate-normalized pulmonary transit times may be a useful index of heart function in mitral regurgitation.
Cough-Associated Changes in CSF Flow in Chiari I Malformation Evaluated by Real-Time MRI.
Bhadelia, R A; Patz, S; Heilman, C; Khatami, D; Kasper, E; Zhao, Y; Madan, N
2016-05-01
Invasive pressure studies have suggested that CSF flow across the foramen magnum may transiently decrease after coughing in patients with symptomatic Chiari I malformation. The purpose of this exploratory study was to demonstrate this phenomenon noninvasively by assessing CSF flow response to coughing in symptomatic patients with Chiari I malformation by using MR pencil beam imaging and to compare the response with that in healthy participants. Eight symptomatic patients with Chiari I malformation and 6 healthy participants were studied by using MR pencil beam imaging with a temporal resolution of ∼50 ms. Patients and healthy participants were scanned for 90 seconds (without cardiac gating) to continuously record cardiac cycle-related CSF flow waveforms in real-time during resting, coughing, and postcoughing periods. CSF flow waveform amplitude, CSF stroke volume, and CSF flow rate (CSF Flow Rate = CSF Stroke Volume × Heart Rate) in the resting and immediate postcoughing periods were determined and compared between patients and healthy participants. There was no significant difference in CSF flow waveform amplitude, CSF stroke volume, and the CSF flow rate between patients with Chiari I malformation and healthy participants during rest. However, immediately after coughing, a significant decrease in CSF flow waveform amplitude (P < .001), CSF stroke volume (P = .001), and CSF flow rate (P = .001) was observed in patients with Chiari I malformation but not in the healthy participants. Real-time MR imaging noninvasively showed a transient decrease in CSF flow across the foramen magnum after coughing in symptomatic patients with Chiari I malformation, a phenomenon not seen in healthy participants. Our results provide preliminary evidence that the physiology-based imaging method used here has the potential to be an objective clinical test to differentiate symptomatic from asymptomatic patients with Chiari I malformation. © 2016 by American Journal of Neuroradiology.
Usselman, Charlotte W; Nielson, Chantelle A; Luchyshyn, Torri A; Gimon, Tamara I; Coverdale, Nicole S; Van Uum, Stan H M; Shoemaker, J Kevin
2016-11-01
We tested the hypothesis that sympathetic responses to baroreceptor unloading may be affected by circulating sex hormones. During lower body negative pressure at -30, -60, and -80 mmHg, muscle sympathetic nerve activity (MSNA), heart rate, and blood pressure were recorded in women who were taking (n = 8) or not taking (n = 9) hormonal contraceptives. All women were tested twice, once during the low-hormone phase (i.e., the early follicular phase of the menstrual cycle and the placebo phase of hormonal contraceptive use), and again during the high-hormone phase (i.e., the midluteal phase of the menstrual cycle and active phase of contraceptive use). During baroreceptor unloading, the reductions in stroke volume and resultant increases in MSNA and total peripheral resistance were greater in high-hormone than low-hormone phases in both groups. When normalized to the fall in stroke volume, increases in MSNA were no longer different between hormone phases. While stroke volume and sympathetic responses were similar between women taking and not taking hormonal contraceptives, mean arterial pressure was maintained during baroreceptor unloading in women not taking hormonal contraceptives but not in women using hormonal contraceptives. These data suggest that differences in sympathetic activation between hormone phases, as elicited by lower body negative pressure, are the result of hormonally mediated changes in the hemodynamic consequences of negative pressure, rather than centrally driven alterations to sympathetic regulation. Copyright © 2016 the American Physiological Society.
NASA Technical Reports Server (NTRS)
Dukhin, Y. O.; Zhukovskyy, L. Y.
1980-01-01
Hemodynamic and periopheral circulation indexes were recorded before, at the end of, and 5 days after 10 days of electrostimulation for 45 min daily, at rest and after a physical loading test. It was found that stroke and minute volume, cardiac output, and regional circulation improved and heart rate and peripheral resistance decreased. The functional state of the cardiac muscle and vascular tone are improved by electrostimulation of selected groups of skeletal muscles.
The Significance of Splenectomy in Experimental Swine Models of Controlled Hemorrhagic Shock
2013-11-01
carefully eval uated in other experimental models of hem orrhage (e.g., uncontrolled hemorrhage, models with concomitant blunt or orthopedic trauma , and...hemorrhagic shock. J Trauma . 2006;61(1):75 81. 3. Pottecher J, Chemla D, Xavier L, et al. The pulse pressure/heart rate ratio as a marker of stroke volume...changes during hemorrhagic shock and resuscitation in anesthetized swine. J Trauma Acute Care Surg. 2013;74(6):1438 1445. 4.Devlin JJ, Kircher SJ
Agha, Syed A; Kalogeropoulos, Andreas P; Shih, Jeffrey; Georgiopoulou, Vasiliki V; Giamouzis, Grigorios; Anarado, Perry; Mangalat, Deepa; Hussain, Imad; Book, Wendy; Laskar, Sonjoy; Smith, Andrew L; Martin, Randolph; Butler, Javed
2009-09-01
Incremental value of echocardiography over clinical parameters for outcome prediction in advanced heart failure (HF) is not well established. We evaluated 223 patients with advanced HF receiving optimal therapy (91.9% angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 92.8% beta-blockers, 71.8% biventricular pacemaker, and/or defibrillator use). The Seattle Heart Failure Model (SHFM) was used as the reference clinical risk prediction scheme. The incremental value of echocardiographic parameters for event prediction (death or urgent heart transplantation) was measured by the improvement in fit and discrimination achieved by addition of standard echocardiographic parameters to the SHFM. After a median follow-up of 2.4 years, there were 38 (17.0%) events (35 deaths; 3 urgent transplants). The SHFM had likelihood ratio (LR) chi(2) 32.0 and C statistic 0.756 for event prediction. Left ventricular end-systolic volume, stroke volume, and severe tricuspid regurgitation were independent echocardiographic predictors of events. The addition of these parameters to SHFM improved LR chi(2) to 72.0 and C statistic to 0.866 (P < .001 and P=.019, respectively). Reclassifying the SHFM-predicted risk with use of the echocardiography-added model resulted in improved prognostic separation. Addition of standard echocardiographic variables to the SHFM results in significant improvement in risk prediction for patients with advanced HF.
Gioia, Laura C; Kate, Mahesh; Sivakumar, Leka; Hussain, Dulara; Kalashyan, Hayrapet; Buck, Brian; Bussiere, Miguel; Jeerakathil, Thomas; Shuaib, Ashfaq; Emery, Derek; Butcher, Ken
2016-07-01
Early anticoagulation after cardioembolic stroke remains controversial because of the potential for hemorrhagic transformation (HT). We tested the safety and feasibility of initiating rivaroxaban ≤14 days after cardioembolic stroke/transient ischemic attack. A prospective, open-label study of patients with atrial fibrillation treated with rivaroxaban ≤14 days of transient ischemic attack or ischemic stroke (National Institute of Health Stroke Scale <9). All patients underwent magnetic resonance imaging <24 hours of rivaroxaban initiation and day 7. The primary end point was symptomatic HT at day 7. Sixty patients (mean±SD age 71±19 years, 82% stroke/18% transient ischemic attack) were enrolled. Median (interquartile range) time from onset to rivaroxaban was 3 (5) days. At treatment initiation, median National Institute of Health Stroke Scale was 2 (4), and median diffusion-weighted imaging volume was 7.9 (13.7) mL. At baseline, HT was present in 25 (42%) patients (hemorrhagic infarct [HI]1=19, HI2=6). On follow-up magnetic resonance imaging, no patients developed symptomatic HT. New asymptomatic HI1 developed in 3 patients, and asymptomatic progression from HI1 to HI2 occurred in 5 patients; otherwise, HT remained unchanged at day 7. These data support the safety of rivaroxaban initiation ≤14 days of mild-moderate cardioembolic stroke/transient ischemic attack. Magnetic resonance imaging evidence of petechial HT, which is common, does not appear to increase the risk of symptomatic HT. © 2016 American Heart Association, Inc.
Diabetes and blood pressure (image)
People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ... People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ...
Protect Your Heart in the Heat
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Structural MRI markers of brain aging early after ischemic stroke.
Werden, Emilio; Cumming, Toby; Li, Qi; Bird, Laura; Veldsman, Michele; Pardoe, Heath R; Jackson, Graeme; Donnan, Geoffrey A; Brodtmann, Amy
2017-07-11
To examine associations between ischemic stroke, vascular risk factors, and MRI markers of brain aging. Eighty-one patients (mean age 67.5 ± 13.1 years, 31 left-sided, 61 men) with confirmed first-ever (n = 66) or recurrent (n = 15) ischemic stroke underwent 3T MRI scanning within 6 weeks of symptom onset (mean 26 ± 9 days). Age-matched controls (n = 40) completed identical testing. Multivariate regression analyses examined associations between group membership and MRI markers of brain aging (cortical thickness, total brain volume, white matter hyperintensity [WMH] volume, hippocampal volume), normalized against intracranial volume, and the effects of vascular risk factors on these relationships. First-ever stroke was associated with smaller hippocampal volume ( p = 0.025) and greater WMH volume ( p = 0.004) relative to controls. Recurrent stroke was in turn associated with smaller hippocampal volume relative to both first-ever stroke ( p = 0.017) and controls ( p = 0.001). These associations remained significant after adjustment for age, sex, education, and, in stroke patients, infarct volume. Total brain volume was not significantly smaller in first-ever stroke patients than in controls ( p = 0.056), but the association became significant after further adjustment for atrial fibrillation ( p = 0.036). Cortical thickness and brain volumes did not differ as a function of stroke type, infarct volume, or etiology. Brain structure is likely to be compromised before ischemic stroke by vascular risk factors. Smaller hippocampal and total brain volumes and increased WMH load represent proxies for underlying vascular brain injury. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
Early Change in Stroke Size Performs Best in Predicting Response to Therapy.
Simpkins, Alexis Nétis; Dias, Christian; Norato, Gina; Kim, Eunhee; Leigh, Richard
2017-01-01
Reliable imaging biomarkers of response to therapy in acute stroke are needed. The final infarct volume and percent of early reperfusion have been used for this purpose. Early fluctuation in stroke size is a recognized phenomenon, but its utility as a biomarker for response to therapy has not been established. This study examined the clinical relevance of early change in stroke volume and compared it with the final infarct volume and percent of early reperfusion in identifying early neurologic improvement (ENI). Acute stroke patients, enrolled between 2013 and 2014 with serial magnetic resonance imaging (MRI) scans (pretreatment baseline, 2 h post, and 24 h post), who received thrombolysis were included in the analysis. Early change in stroke volume, infarct volume at 24 h on diffusion, and percent of early reperfusion were calculated from the baseline and 2 h MRI scans were compared. ENI was defined as ≥4 point decrease in National Institutes of Health Stroke Scales within 24 h. Logistic regression models and receiver operator characteristics analysis were used to compare the efficacy of 3 imaging biomarkers. Serial MRIs of 58 acute stroke patients were analyzed. Early change in stroke volume was significantly associated with ENI by logistic regression analysis (OR 0.93, p = 0.048) and remained significant after controlling for stroke size and severity (OR 0.90, p = 0.032). Thus, for every 1 mL increase in stroke volume, there was a 10% decrease in the odds of ENI, while for every 1 mL decrease in stroke volume, there was a 10% increase in the odds of ENI. Neither infarct volume at 24 h nor percent of early reperfusion were significantly associated with ENI by logistic regression. Receiver-operator characteristic analysis identified early change in stroke volume as the only biomarker of the 3 that performed significantly different than chance (p = 0.03). Early fluctuations in stroke size may represent a more reliable biomarker for response to therapy than the more traditional measures of final infarct volume and percent of early reperfusion. © 2017 S. Karger AG, Basel.
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Frontera, Jennifer A; Starling, Randall; Cho, Sung-Min; Nowacki, Amy S; Uchino, Ken; Hussain, M Shazam; Mountis, Maria; Moazami, Nader
2017-06-01
Stroke is a major cause of mortality after left ventricular assist device (LVAD) placement. Prospectively collected data of patients with HeartMate II (n = 332) and HeartWare (n = 70) LVADs from October 21, 2004, to May 19, 2015, were reviewed. Predictors of early (during index hospitalization) and late (post-discharge) ischemic and hemorrhagic stroke and association of stroke subtypes with mortality were assessed. Of 402 patients, 83 strokes occurred in 69 patients (17%; 0.14 events per patient-year [EPPY]): early ischemic stroke in 18/402 (4%; 0.03 EPPY), early hemorrhagic stroke in 11/402 (3%; 0.02 EPPY), late ischemic stroke in 25/402 (6%; 0.04 EPPY) and late hemorrhagic stroke in 29/402 (7%; 0.05 EPPY). Risk of stroke and death among patients with stroke was bimodal with highest risks immediately post-implant and increasing again 9-12 months later. Risk of death declined over time in patients without stroke. Modifiable stroke risk factors varied according to timing and stroke type, including tobacco use, bacteremia, pump thrombosis, pump infection, and hypertension (all p < 0.05). In multivariable analysis, early hemorrhagic stroke (adjusted odds ratio [aOR] 4.3, 95% confidence interval [CI] 1.0-17.8, p = 0.04), late ischemic stroke (aOR 3.2, 95% CI 1.1-9.0, p = 0.03), and late hemorrhagic stroke (aOR 3.7, 95% CI 1.5-9.2, p = 0.005) predicted death, whereas early ischemic stroke did not. Stroke is a leading cause and predictor of death in patients with LVADs. Risk of stroke and death among patients with stroke is bimodal, with highest risk at time of implant and increasing risk again after 9-12 months. Management of modifiable risk factors may reduce stroke and mortality rates. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
Fonarow, Gregg C; Alberts, Mark J; Broderick, Joseph P; Jauch, Edward C; Kleindorfer, Dawn O; Saver, Jeffrey L; Solis, Penelope; Suter, Robert; Schwamm, Lee H
2014-05-01
Because stroke is among the leading causes of death, disability, hospitalizations, and healthcare expenditures in the United States, there is interest in reporting outcomes for patients hospitalized with acute ischemic stroke. The American Heart Association/American Stroke Association, as part of its commitment to promote high-quality, evidence-based care for cardiovascular and stroke patients, fully supports the development of properly risk-adjusted outcome measures for stroke. To accurately assess and report hospital-level outcomes, adequate risk adjustment for case mix is essential. During the development of the Centers for Medicare & Medicaid Services 30-day stroke mortality and 30-day stroke readmission measures, concerns were expressed that these measures were not adequately designed because they do not include a valid initial stroke severity measure, such as the National Institutes of Health Stroke Scale. These outcome measures, as currently constructed, may be prone to mischaracterizing the quality of stroke care being delivered by hospitals and may ultimately harm acute ischemic stroke patients. This article details (1) why the Centers for Medicare & Medicaid Services acute ischemic stroke outcome measures in their present form may not provide adequate risk adjustment, (2) why the measures as currently designed may lead to inaccurate representation of hospital performance and have the potential for serious unintended consequences, (3) what activities the American Heart Association/American Stroke Association has engaged in to highlight these concerns to the Centers for Medicare & Medicaid Services and other interested parties, and (4) alternative approaches and opportunities that should be considered for more accurately risk-adjusting 30-day outcomes measures in patients with ischemic stroke.
Demaerschalk, Bart M; Kleindorfer, Dawn O; Adeoye, Opeolu M; Demchuk, Andrew M; Fugate, Jennifer E; Grotta, James C; Khalessi, Alexander A; Levy, Elad I; Palesch, Yuko Y; Prabhakaran, Shyam; Saposnik, Gustavo; Saver, Jeffrey L; Smith, Eric E
2016-02-01
To critically review and evaluate the science behind individual eligibility criteria (indication/inclusion and contraindications/exclusion criteria) for intravenous recombinant tissue-type plasminogen activator (alteplase) treatment in acute ischemic stroke. This will allow us to better inform stroke providers of quantitative and qualitative risks associated with alteplase administration under selected commonly and uncommonly encountered clinical circumstances and to identify future research priorities concerning these eligibility criteria, which could potentially expand the safe and judicious use of alteplase and improve outcomes after stroke. Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association's Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge and, when appropriate, formulated recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on and approved the final version of this document. The document underwent extensive American Heart Association internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee. After a review of the current literature, it was clearly evident that the levels of evidence supporting individual exclusion criteria for intravenous alteplase vary widely. Several exclusionary criteria have already undergone extensive scientific study such as the clear benefit of alteplase treatment in elderly stroke patients, those with severe stroke, those with diabetes mellitus and hyperglycemia, and those with minor early ischemic changes evident on computed tomography. Some exclusions such as recent intracranial surgery are likely based on common sense and sound judgment and are unlikely to ever be subjected to a randomized, clinical trial to evaluate safety. Most other contraindications or warnings range somewhere in between. However, the differential impact of each exclusion criterion varies not only with the evidence base behind it but also with the frequency of the exclusion within the stroke population, the probability of coexistence of multiple exclusion factors in a single patient, and the variation in practice among treating clinicians. © 2015 American Heart Association, Inc.
Heart Disease, Stroke, or Other Cardiovascular Disease and Adult Vaccination
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Social Deprivation and Initial Presentation of 12 Cardiovascular Diseases: a CALIBER Study
2013-09-03
Abdominal Aortic Aneurysm; Coronary Heart Disease NOS; Unheralded Corronary Death; Intracerebral Haemorrhage; Heart Failure; Ischemic Stroke; Myocardial Infarction; Stroke; Peripheral Arterial Disease; Stable Angina Pectoris; Subarachnoid Haemorrhage; Transient Ischemic Attack; Unstable Angina; Cardiac Arrest, Sudden Cardiac Death
The role of exercise in cardiovascular rehabilitation: a review.
Koutroumpi, Matina; Pitsavos, Christos; Stefanadis, Christodoulos
2008-02-01
The epidemiological literature supports an inverse association and a dose-response gradient between exercise training and both cardiovascular disease in general and coronary artery disease in particular. An overwhelming number of studies has supported similar findings for hypertension, dyslipidaemia, obesity, diabetes, inflammatory and coagulation markers related to cardiovascular disease and cardiac heart failure. Findings are highly suggestive that endurance type exercise training, of moderate intensity most days of the week can lower blood pressure in patients with hypertension, can decrease triglyceride levels and increase HDL cholesterol levels in patients with dyslipidaemia, reduces body weight when combined with diet, improves insulin sensitivity, modifies the inflammatory process and finally can improve stroke volume and reduce cardiomegaly in patients with cardiac heart failure.
Hospital Variation in Functional Recovery After Stroke.
Bettger, Janet Prvu; Thomas, Laine; Liang, Li; Xian, Ying; Bushnell, Cheryl D; Saver, Jeffrey L; Fonarow, Gregg C; Peterson, Eric D
2017-01-01
Functional status is a key patient-centric outcome, but there are little data on whether functional recovery post-stroke varies among hospitals. This study examined the distribution of functional status 3 months after stroke, determined whether these outcomes vary among hospitals, and identified hospital characteristics associated with better (or worse) functional outcomes. Observational analysis of the AVAIL study (Adherence Evaluation After Ischemic Stroke-Longitudinal) included 2083 ischemic stroke patients enrolled from 82 US hospitals participating in Get With The Guidelines-Stroke and AVAIL. The primary outcome was dependence or death at 3 months (modified Rankin Scale [mRS] score of 3-6). Secondary outcomes included functional dependence (mRS score of 3-5), disabled (mRS score of 2-5), and mRS evaluated as a continuous score. By 3 months post-discharge, 36.5% of patients were functionally dependent or dead. Rates of dependence or death varied widely by discharging hospitals (range: 0%-67%). After risk adjustment, patients had lower rates of 3-month dependence or death when treated at teaching hospitals (odds ratio, 0.72; 95% confidence interval, 0.54-0.96) and certified primary stroke centers (odds ratio, 0.69; 95% confidence interval, 0.53-0.91). In contrast, a composite measure of hospital-level adherence to acute stroke care performance metrics, stroke volume, and bed size was not associated with downstream patient functional status. Findings were robust across mRS end points and sensitivity analyses. One third of acute ischemic stroke patients were functionally dependent or dead 3 months postacute stroke; functional recovery rates varied considerably among hospitals, supporting the need to better determine which care processes can maximize functional outcomes. © 2017 American Heart Association, Inc.
Cumbler, Ethan; Wald, Heidi; Bhatt, Deepak L; Cox, Margueritte; Xian, Ying; Reeves, Mathew; Smith, Eric E; Schwamm, Lee; Fonarow, Gregg C
2014-01-01
Analysis of quality of care for in-hospital stroke has not been previously performed at the national level. This study compares patient characteristics, process measures of quality, and outcomes for in-hospital strokes with those for community-onset strokes in a national cohort. We performed a retrospective cohort study of the Get With The Guidelines-Stroke (GWTG-Stroke) database of The American Heart Association from January 2006 to April 2012, using data from 1280 sites that reported ≥1 in-hospital stroke. Patient characteristics, comorbid illnesses, medications, quality of care measures, and outcomes were analyzed for 21 349 in-hospital ischemic strokes compared with 928 885 community-onset ischemic strokes. Patients with in-hospital stroke had more thromboembolic risk factors, including atrial fibrillation, prosthetic heart valves, carotid stenosis, and heart failure (P<0.0001), and experienced more severe strokes (median National Institutes of Health Stroke Score 9.0 versus 4.0; P<0.0001). Using GWTG-Stroke achievement measures, the proportion of patients with defect-free care was lower for in-hospital strokes (60.8% versus 82.0%; P<0.0001). After accounting for patient and hospital characteristics, patients with in-hospital strokes were less likely to be discharged home (adjusted odds ratio 0.37; 95% confidence intervals [0.35-0.39]) or be able to ambulate independently at discharge (adjusted odds ratio 0.42; 95% confidence intervals [0.39-0.45]). In-hospital mortality was higher for in-hospital stroke (adjusted odds ratio 2.72; 95% confidence intervals [2.57-2.88]). Compared with community-onset ischemic stroke, patients with in-hospital stroke experienced more severe strokes, received lower adherence to process-based quality measures, and had worse outcomes. These findings suggest there is an important opportunity for targeted quality improvement efforts for patients with in-hospital stroke.
Berg, Robert A; Sorrell, Vincent L; Kern, Karl B; Hilwig, Ronald W; Altbach, Maria I; Hayes, Melinda M; Bates, Kathryn A; Ewy, Gordon A
2005-03-08
Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms. Ventricular dimensions were determined by MRI for 30 minutes of untreated VF in a closed-chest, closed-pericardium model in 6 swine. Within 1 minute of untreated VF, mean right ventricular volume increased by 29% but did not increase thereafter. During the first 5 minutes of untreated VF, mean left ventricular volume increased by 34%. Between 20 and 30 minutes of VF, stone heart occurred as manifested by dramatic thickening of the myocardium and concomitant substantial decreases in left ventricular volume. In this closed-chest swine model of VF, substantial right ventricular volume changes occurred early and did not result in smaller left ventricular volumes. The changes in ventricular volumes before the late development of stone heart do not explain why defibrillation from brief duration VF (<5 minutes) typically results in a pulsatile rhythm with return of spontaneous circulation, whereas defibrillation from prolonged VF (5 to 15 minutes) does not.
Sleep disturbance, stroke, and heart disease events: evidence from the Caerphilly cohort
Elwood, Peter; Hack, Melissa; Pickering, Janet; Hughes, Janie; Gallacher, John
2006-01-01
Objective To test the hypothesis that sleep disorders are relevant to the risk of ischaemic stroke and ischaemic heart disease events in older men. Design A cohort study. Setting The Caerphilly cohort, a representative population sample of older men in South Wales, UK. Participants 1986 men aged 55–69 years completed a questionnaire on sleep patterns with help from their partners. This asked about symptoms of disturbed sleep: insomnia, snoring, restless legs, obstructive sleep apnoea, and about daytime sleepiness. During the following 10 years 107 men experienced an ischaemic stroke and 213 had an ischaemic heart disease event. Main results Up to one third of the men reported at least one symptom suggestive of sleep disturbance, and one third reported daytime sleepiness. Compared with men who reported no such symptoms, the adjusted relative odds of an ischaemic stroke were significantly increased in men with any sleep disturbance, the strongest association being with sleep apnoea (relative odds 1.97; 1.26 to 3.09). The association with daytime sleepiness was not significant for stroke. Relations with ischaemic heart disease events were all raised in men with symptoms of sleep disturbance, but none was significant, other than daytime sleepiness (relative odds: 1.41; 1.04 to 1.92). There were no significant relations with blood pressure. Conclusion The risk of an ischaemic stroke is increased in men whose sleep is frequently disturbed, and daytime sleepiness is associated with a significant increase in ischaemic heart disease events. PMID:16361457
Furlanis, Giovanni; Ajčević, Miloš; Stragapede, Lara; Lugnan, Carlo; Ridolfi, Mariana; Caruso, Paola; Naccarato, Marcello; Ukmar, Maja; Manganotti, Paolo
2018-04-30
The National Institutes of Health Stroke Scale (NIHSS) is the most adopted stroke patients' evaluation tool in emergency settings to assess the severity of stroke and to determine the patients' eligibility for specific treatments. Computed tomography perfusion (CTP) is crucial to identify salvageable tissue that can benefit from the reperfusion treatment. The aim of this study is to identify the relation between the NIHSS scores and the hypoperfused volumes evaluated by CTP in patients with hyperacute ischemic stroke. This retrospective study was conducted on 105 patients with ischemic stroke who underwent NIHSS assessment and CTP in the hyperacute phase. Hypoperfused volume was evaluated by CTP maps processed with semi-automatic algorithm. An analysis was conducted to determine the degree of correlation between the NIHSS scores and the ischemic lesion volumes and to investigate the relation between the anterior and the posterior circulation strokes, as well as between the right and the left hemispheric strokes. A significant correlation was found between ischemic volume and NIHSS score at baseline (r = .82; P < .0001) in the entire cohort. A high NIHSS-volume correlation was identified in the anterior circulation stroke (r = .76; P < .0001); whereas, it was nonsignificant in the posterior circulation stroke. NIHSS score and volume correlated for the left and the right hemispheric strokes (r = .83 and .81; P < .0001), showing a slightly higher slope in the left. This study showed a strong correlation between the baseline NIHSS score and the ischemic volume estimated by CTP. We confirmed that NIHSS is a reliable predictor of perfusion deficits in acute ischemic stroke. CTP allows fast imaging assessment in the hyperacute phase. The results highlight the importance of these diagnostic tools in the assessment of stroke severity and in acute decision-making. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Cardiovascular responses associated with daily walking in subacute stroke.
Prajapati, Sanjay K; Mansfield, Avril; Gage, William H; Brooks, Dina; McIlroy, William E
2013-01-01
Despite the importance of regaining independent ambulation after stroke, the amount of daily walking completed during in-patient rehabilitation is low. The purpose of this study is to determine if (1) walking-related heart rate responses reached the minimum intensity necessary for therapeutic aerobic exercise (40%-60% heart rate reserve) or (2) heart rate responses during bouts of walking revealed excessive workload that may limit walking (>80% heart rate reserve). Eight individuals with subacute stroke attending in-patient rehabilitation were recruited. Participants wore heart rate monitors and accelerometers during a typical rehabilitation day. Walking-related changes in heart rate and walking bout duration were determined. Patients did not meet the minimum cumulative requirements of walking intensity (>40% heart rate reserve) and duration (>10 minutes continuously) necessary for cardiorespiratory benefit. Only one patient exceeded 80% heart rate reserve. The absence of significant increases in heart rate associated with walking reveals that patients chose to walk at speeds well below a level that has meaningful cardiorespiratory health benefits. Additionally, cardiorespiratory workload is unlikely to limit participation in walking. Measurement of heart rate and walking during in-patient rehabilitation may be a useful approach to encourage patients to increase the overall physical activity and to help facilitate recovery.
Risks for Heart Disease & Stroke
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Eicken, Andreas; Michel, Julia; Hager, Alfred; Tanase, Daniel; Kaemmerer, Harald; Cleuziou, Julie; Hess, John; Ewert, Peter
2017-02-01
The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls. Median cardiac output was significantly lower in the ABR group (2.2 vs. 2.6 l/min/m 2 ; p = 0.015), and systemic resistance was significantly elevated (28.9 vs. 22.2 U m 2 ; p = 0.04) in comparison with normals. While stroke volume rose by 27% in the control group, it dropped by 7% in patients after ABR at atrial pacing (80/min). Stroke volume increase after dobutamine was significantly lower after ABR in comparison with normal controls (34 vs. 106%; p = 0.001). Higher NYHA class (p = 0.043), degree of tricuspid regurgitation (p = 0.009) and ventricular function (p = 0.028) were associated with lower stroke volume increase. Limited exercise capability of patients after ABR for TGA is primarily due to limited diastolic filling of the ventricles due to stiff non-compliant atrial pathways. Elevated systemic resistance may lead to severe myocardial hypertrophy with possible ischemia and contribute to the multifactorial decline of ventricular function in some patients.
Prediction of morbidity and mortality in patients with type 2 diabetes.
Wells, Brian J; Roth, Rachel; Nowacki, Amy S; Arrigain, Susana; Yu, Changhong; Rosenkrans, Wayne A; Kattan, Michael W
2013-01-01
Introduction. The objective of this study was to create a tool that accurately predicts the risk of morbidity and mortality in patients with type 2 diabetes according to an oral hypoglycemic agent. Materials and Methods. The model was based on a cohort of 33,067 patients with type 2 diabetes who were prescribed a single oral hypoglycemic agent at the Cleveland Clinic between 1998 and 2006. Competing risk regression models were created for coronary heart disease (CHD), heart failure, and stroke, while a Cox regression model was created for mortality. Propensity scores were used to account for possible treatment bias. A prediction tool was created and internally validated using tenfold cross-validation. The results were compared to a Framingham model and a model based on the United Kingdom Prospective Diabetes Study (UKPDS) for CHD and stroke, respectively. Results and Discussion. Median follow-up for the mortality outcome was 769 days. The numbers of patients experiencing events were as follows: CHD (3062), heart failure (1408), stroke (1451), and mortality (3661). The prediction tools demonstrated the following concordance indices (c-statistics) for the specific outcomes: CHD (0.730), heart failure (0.753), stroke (0.688), and mortality (0.719). The prediction tool was superior to the Framingham model at predicting CHD and was at least as accurate as the UKPDS model at predicting stroke. Conclusions. We created an accurate tool for predicting the risk of stroke, coronary heart disease, heart failure, and death in patients with type 2 diabetes. The calculator is available online at http://rcalc.ccf.org under the heading "Type 2 Diabetes" and entitled, "Predicting 5-Year Morbidity and Mortality." This may be a valuable tool to aid the clinician's choice of an oral hypoglycemic, to better inform patients, and to motivate dialogue between physician and patient.
Wellons, Melissa; Ouyang, Pamela; Schreiner, Pamela J; Herrington, David M; Vaidya, Dhananjay
2012-10-01
Cardiovascular disease is the number one killer of women. Identifying women at risk of cardiovascular disease has tremendous public health importance. Early menopause is associated with increased cardiovascular disease events in some predominantly white populations, but not consistently. Our objective was to determine if self-reported early menopause (menopause at an age <46 y) identifies women as at risk for future coronary heart disease or stroke. The study population came from the Multi-Ethnic Study of Atherosclerosis, a longitudinal, ethnically diverse cohort study of US men and women aged 45 to 84 years enrolled in 2000-2002 and followed up until 2008. The association between a personal history of early menopause (either natural menopause or surgical removal of ovaries at an age <46 y) and future coronary heart disease and stroke was assessed in 2,509 women (ages 45-84 y; 987 white, 331 Chinese, 641 black, and 550 Hispanic) from the Multi-ethnic Study Atherosclerosis who were free of cardiovascular disease at baseline. Of 2,509 women, 693 (28%) reported either surgical or natural early menopause. In survival curves, women with early menopause had worse coronary heart disease and stroke-free survival (log rank P = 0.008 and P = 0.0158). In models adjusted for age, race/ethnicity, Multi-ethnic Study Atherosclerosis site, and traditional cardiovascular disease risk factors, this risk for coronary heart disease and stroke remained (hazard ratio, 2.08; 95% CI, 1.17-3.70; and hazard ratio, 2.19; 95% CI, 1.11-4.32, respectively). Early menopause is positively associated with coronary heart disease and stroke in a multiethnic cohort, independent of traditional cardiovascular disease risk factors.
Wellons, Melissa; Ouyang, Pamela; Schreiner, Pamela J; Herrington, David M; Vaidya, Dhananjay
2012-01-01
Objective Cardiovascular disease is the number one killer of women. Identifying women at risk of cardiovascular disease has tremendous public health importance. Early menopause is associated with increased cardiovascular disease events in some predominantly white populations, but not consistently. Our objective was to determine if a self-reported early menopause (menopause at an age <46) identifies women as at risk for future coronary heart disease or stroke. Methods The study population came from the Multi-Ethnic Study of Atherosclerosis, a longitudinal, ethnically diverse cohort study of US men and women aged 45 to 84 years enrolled in 2000–2002 and followed up until 2008. The association between a personal history of early menopause (either natural menopause or surgical removal of ovaries at an age <46) and future coronary heart disease and stroke was assessed in 2509 women (ages 45–84, 987 White, 331 Chinese, 641 Black, 550 Hispanic) from the Multi-Ethnic Study Atherosclerosis, who were free of cardiovascular disease at baseline. Results 693/2509 (28%) of women reported either surgical or natural early menopause. In survival curves, women with early menopause had worse coronary heart disease and stroke-free survival (log rank p=<0.008 and 0.0158). In models adjusted for age, race/ethnicity, Multi-Ethnic Study Atherosclerosis site and traditional cardiovascular disease risk factors, this risk for coronary heart disease and stroke remained (HR 2.08, 95% CI 1.17, 3.70 and 2.19, 95% CI 1.11, 4.32, respectively). Conclusions Early menopause is positively associated with coronary heart disease and stroke in a multiethnic cohort, independent of traditional cardiovascular disease risk factors. PMID:22692332
Del Brutto, Oscar H; Mera, Robertino M; Montalván, Martha; Del Brutto, Victor J; Zambrano, Mauricio; Santamaría, Milton; Tettamanti, Daniel
2014-04-01
Knowledge of regional-specific cardiovascular risk factors is mandatory to reduce the growing burden of stroke and ischemic heart disease in Latin American populations. We conducted a population-based case-control study to assess which risk factors are associated with the occurrence of vascular events in natives/mestizos living in rural coastal Ecuador. We assessed the cardiovascular health (CVH) status and the presence of the metabolic syndrome in all Atahualpa residents aged 40 years or more with stroke and ischemic heart disease and in randomly selected healthy persons to evaluate differences in the prevalence of such risk factors between patients and controls. A total of 120 persons (24 with stroke or ischemic heart disease and 96 matched controls) were included. A poor CVH status (according to the American Heart Association) was found in 87.5% case-patients and 81.3% controls (P = .464). The metabolic syndrome was present in the same proportion (58.3%) of case-patients and controls. Likewise, both sets of risk factors (poor CVH status and the metabolic syndrome) were equally prevalent among both groups (58.3% versus 49%, P = .501). This case-control study suggests that none of the measured risk factors is associated with the occurrence of vascular events. It is possible that some yet unmeasured risk factors or an unknown genetic predisposition may account for a sizable proportion of stroke and ischemic heart disease occurring in the native/mestizo population of rural coastal Ecuador. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Stroke as the Initial Manifestation of Atrial Fibrillation: The Framingham Heart Study.
Lubitz, Steven A; Yin, Xiaoyan; McManus, David D; Weng, Lu-Chen; Aparicio, Hugo J; Walkey, Allan J; Rafael Romero, Jose; Kase, Carlos S; Ellinor, Patrick T; Wolf, Philip A; Seshadri, Sudha; Benjamin, Emelia J
2017-02-01
To prevent strokes that may occur as the first manifestation of atrial fibrillation (AF), screening programs have been proposed to identify patients with undiagnosed AF who may be eligible for treatment with anticoagulation. However, the frequency with which patients with AF present with stroke as the initial manifestation of the arrhythmia is unknown. We estimated the frequency with which AF may present as a stroke in 1809 community-based Framingham Heart Study participants with first-detected AF and without previous strokes, by tabulating the frequencies of strokes occurring on the same day, within 30 days before, 90 days before, and 365 days before first-detected AF. Using previously reported AF incidence rates, we estimated the incidence of strokes that may represent the initial manifestation of AF. We observed 87 strokes that occurred ≤1 year before AF detection, corresponding to 1.7% on the same day, 3.4% within 30 days before, 3.7% within 90 days before, and 4.8% ≤1 year before AF detection. We estimated that strokes may present as the initial manifestation of AF at a rate of 2 to 5 per 10 000 person-years, in both men and women. We observed that stroke is an uncommon but measureable presenting feature of AF. Our data imply that emphasizing cost-effectiveness of population-wide AF-screening efforts will be important given the relative infrequency with which stroke represents the initial manifestation of AF. © 2017 American Heart Association, Inc.
A new approach for low-cost noninvasive detection of asymptomatic heart disease at rest.
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.
Knoepfli-Lenzin, C; Sennhauser, C; Toigo, M; Boutellier, U; Bangsbo, J; Krustrup, P; Junge, A; Dvorak, J
2010-04-01
The present study examined the effect of football (F, n=15) training on the health profile of habitually active 25-45-year-old men with mild hypertension and compared it with running (R, n=15) training and no additional activity (controls, C, n=17). The participants in F and R completed a 1-h training session 2.4 times/week for 12 weeks. Systolic and diastolic blood pressure decreased in all groups but the decrease in diastolic blood pressure in F (-9 +/- 5 (+/- SD) mmHg) was higher than that in C (-4 +/- 6 mmHg). F was as effective as R in decreasing body mass (-1.6 +/- 1.8 vs-1.5 +/- 2.1 kg) and total fat mass (-2.0 +/- 1.5 vs -1.6 +/- 1.5 kg) and in increasing supine heart rate variability, whereas no changes were detected for C. Maximal stroke volume improved in F (+13.1%) as well as in R (+10.1%) compared with C (-4.9%). Total cholesterol decreased in F (5.8 +/- 1.2 to 5.5 +/- 0.9 mmol/L) but was not altered in R and C. We conclude that football training, consisting of high-intensity intermittent exercise, results in positive effects on blood pressure, body composition, stroke volume and supine heart rate variability, and elicits at least the same cardiovascular health benefits as continuous running exercise in habitually active men with mild hypertension.
The effects of malnutrition on cardiac function in African children.
Silverman, Jonathan A; Chimalizeni, Yamikani; Hawes, Stephen E; Wolf, Elizabeth R; Batra, Maneesh; Khofi, Harriet; Molyneux, Elizabeth M
2016-02-01
Cardiac dysfunction may contribute to high mortality in severely malnourished children. Our objective was to assess the effect of malnutrition on cardiac function in hospitalised African children. Prospective cross-sectional study. Public referral hospital in Blantyre, Malawi. We enrolled 272 stable, hospitalised children ages 6-59 months, with and without WHO-defined severe acute malnutrition. Cardiac index, heart rate, mean arterial pressure, stroke volume index and systemic vascular resistance index were measured by the ultrasound cardiac output monitor (USCOM, New South Wales, Australia). We used linear regression with generalised estimating equations controlling for age, sex and anaemia. Our primary outcome, cardiac index, was similar between those with and without severe malnutrition: difference=0.22 L/min/m(2) (95% CI -0.08 to 0.51). No difference was found in heart rate or stroke volume index. However, mean arterial pressure and systemic vascular resistance index were lower in children with severe malnutrition: difference=-8.6 mm Hg (95% CI -12.7 to -4.6) and difference=-200 dyne s/cm(5)/m(2) (95% CI -320 to -80), respectively. In this largest study to date, we found no significant difference in cardiac function between hospitalised children with and without severe acute malnutrition. Further study is needed to determine if cardiac function is diminished in unstable malnourished children. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Brunner, Eric J; Shipley, Martin J; Britton, Annie R; Stansfeld, Stephen A; Heuschmann, Peter U; Rudd, Anthony G; Wolfe, Charles D A; Singh-Manoux, Archana; Kivimaki, Mika
2014-03-01
Systematic reviews examining associations of depressive disorder with coronary heart disease and stroke produce mixed results. Failure to consider reverse causation and dose-response patterns may have caused inconsistencies in evidence. This prospective cohort study on depressive disorder, coronary heart disease, and stroke analysed reverse causation and dose-response effects using four 5-year and three 10-year observation cycles (total follow up 24 years) based on multiple repeat measures of exposure. Participants in the Whitehall II study (n = 10,036, 31,395 person-observations, age at start 44.4 years) provided up to six repeat measures of depressive symptoms via the 30-item General Health Questionnaire (GHQ-30) and one measure via Center for Epidemiologic Studies Depression Scale (CES-D). The cohort was followed up for major coronary events (coronary death/nonfatal myocardial infarction) and stroke (stroke death/morbidity) through the national mortality register Hospital Episode Statistics, ECG-screening, medical records, and self-report questionnaires. GHQ-30 caseness predicted stroke over 0-5 years (age-, sex- and ethnicity-adjusted HR 1.60, 95% CI 1.1-2.3) but not over 5-10 years (HR 0.94, 95% CI 0.6-1.4). Using the last 5-year observation cycle, cumulative GHQ-30 caseness was associated with incident coronary heart disease in a dose-response manner (1-2 times a case: HR 1.12, 95% CI 0.7-1.7; 3-4 times: HR 2.06, 95% CI 1.2-3.7), and CES-D caseness predicted coronary heart disease (HR 1.81, 95% CI 1.1-3.1). There was evidence of a dose-response effect of depressive symptoms on risk of coronary heart disease. In contrast, prospective associations of depressive symptoms with stroke appeared to arise wholly or partly through reverse causation.
Holloway, Robert G; Arnold, Robert M; Creutzfeldt, Claire J; Lewis, Eldrin F; Lutz, Barbara J; McCann, Robert M; Rabinstein, Alejandro A; Saposnik, Gustavo; Sheth, Kevin N; Zahuranec, Darin B; Zipfel, Gregory J; Zorowitz, Richard D
2014-06-01
The purpose of this statement is to delineate basic expectations regarding primary palliative care competencies and skills to be considered, learned, and practiced by providers and healthcare services across hospitals and community settings when caring for patients and families with stroke. Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association's Manuscript Oversight Committee. Members were chosen to reflect the diversity and expertise of professional roles in delivering optimal palliative care. Writing group members were assigned topics relevant to their areas of expertise, reviewed the appropriate literature, and drafted manuscript content and recommendations in accordance with the American Heart Association's framework for defining classes and level of evidence and recommendations. The palliative care needs of patients with serious or life-threatening stroke and their families are enormous: complex decision making, aligning treatment with goals, and symptom control. Primary palliative care should be available to all patients with serious or life-threatening stroke and their families throughout the entire course of illness. To optimally deliver primary palliative care, stroke systems of care and provider teams should (1) promote and practice patient- and family-centered care; (2) effectively estimate prognosis; (3) develop appropriate goals of care; (4) be familiar with the evidence for common stroke decisions with end-of-life implications; (5) assess and effectively manage emerging stroke symptoms; (6) possess experience with palliative treatments at the end of life; (7) assist with care coordination, including referral to a palliative care specialist or hospice if necessary; (8) provide the patient and family the opportunity for personal growth and make bereavement resources available if death is anticipated; and (9) actively participate in continuous quality improvement and research. Addressing the palliative care needs of patients and families throughout the course of illness can complement existing practices and improve the quality of life of stroke patients, their families, and their care providers. There is an urgent need for further research in this area. © 2014 American Heart Association, Inc.
Aspirin for Reducing Your Risk of Heart Attack and Stroke: Know the Facts
... the medicines (prescription and over-the-counter) and dietary supplements, including vitamins and herbals, that you use — even if only occasionally. FACT: Aspirin is a drug If you are at risk for heart attack or stroke your doctor may ...
Heart failure: when form fails to follow function.
Katz, Arnold M; Rolett, Ellis L
2016-02-01
Cardiac performance is normally determined by architectural, cellular, and molecular structures that determine the heart's form, and by physiological and biochemical mechanisms that regulate the function of these structures. Impaired adaptation of form to function in failing hearts contributes to two syndromes initially called systolic heart failure (SHF) and diastolic heart failure (DHF). In SHF, characterized by high end-diastolic volume (EDV), the left ventricle (LV) cannot eject a normal stroke volume (SV); in DHF, with normal or low EDV, the LV cannot accept a normal venous return. These syndromes are now generally defined in terms of ejection fraction (EF): SHF became 'heart failure with reduced ejection fraction' (HFrEF) while DHF became 'heart failure with normal or preserved ejection fraction' (HFnEF or HFpEF). However, EF is a chimeric index because it is the ratio between SV--which measures function, and EDV--which measures form. In SHF the LV dilates when sarcomere addition in series increases cardiac myocyte length, whereas sarcomere addition in parallel can cause concentric hypertrophy in DHF by increasing myocyte thickness. Although dilatation in SHF allows the LV to accept a greater venous return, it increases the energy cost of ejection and initiates a vicious cycle that contributes to progressive dilatation. In contrast, concentric hypertrophy in DHF facilitates ejection but impairs filling and can cause heart muscle to deteriorate. Differences in the molecular signals that initiate dilatation and concentric hypertrophy can explain why many drugs that improve prognosis in SHF have little if any benefit in DHF. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
Dipla, Konstantina; Kousoula, Dimitra; Zafeiridis, Andreas; Karatrantou, Konstantina; Nikolaidis, Michalis G; Kyparos, Antonios; Gerodimos, Vassilis; Vrabas, Ioannis S
2016-06-01
What is the central question of this study? In obesity, the exaggerated blood pressure response to voluntary exercise is linked to hypertension, yet the mechanisms are not fully elucidated. We examined whether involuntary contractions elicit greater haemodynamic responses and altered neural control of blood pressure in normotensive obese versus lean women. What is the main finding and its importance? During involuntary contractions induced by whole-body vibration, there were augmented blood pressure and spontaneous baroreflex responses in obese compared with lean women. This finding is suggestive of an overactive mechanoreflex in the exercise-induced hypertensive response in obesity. Passive contractions did not elicit differential heart rate responses in obese compared with lean women, implying other mechanisms for the blunted heart rate response reported during voluntary exercise in obesity. In obesity, the exaggerated blood pressure (BP) response to exercise is linked to hypertension, yet the mechanisms are not fully elucidated. In this study, we examined whether involuntary mechanical oscillations, induced by whole-body vibration (WBV), elicit greater haemodynamic responses and altered neural control of BP in obese versus lean women. Twenty-two normotensive, premenopausal women (12 lean and 10 obese) randomly underwent a passive WBV (25 Hz) and a control protocol (similar posture without WVB). Beat-by-beat BP, heart rate, stroke volume, systemic vascular resistance, cardiac output, parasympathetic output (evaluated by heart rate variability) and spontaneous baroreceptor sensitivity (sBRS) were assessed. We found that during WBV, obese women exhibited an augmented systolic BP response compared with lean women that was correlated with body fat percentage (r = 0.77; P < 0.05). The exaggerated BP rise was driven mainly by the greater increase in cardiac output index in obese versus lean women, associated with a greater stroke volume index in obese women. Involuntary contractions did not elicit a differential magnitude of responses in heart rate, heart rate variability indices and systemic vascular resistance in obese versus lean women; however, they did result in greater sBRS responses (P < 0.05) in obese women. In conclusion, involuntary contractions elicited an augmented BP and sBRS response in normotensive obese versus lean women. The greater elevations in circulatory haemodynamics in obese women are suggestive of an overactive mechanoreflex in the exercise-induced hypertensive response in obesity. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.
Rehabilitation of Older Persons Disabled by Cancer, Stroke, and Heart Disease.
ERIC Educational Resources Information Center
Finnerty-Fried, Pamela; And Others
1986-01-01
Rehabilitation of older persons disabled by cancer, stroke, or heart disease is discussed. Aspects of each disability are described, and the importance of timely and appropriate intervention with older persons is emphasized. Barriers generally faced by older disabled persons are briefly outlined. (Author)
Coats, Brandon W; Sharp, M Keith
2010-03-01
One proposed method to overcome postflight orthostatic intolerance is for astronauts to undergo inflight centrifugation. Cardiovascular responses were compared between centrifuge and gravitational conditions using a seven-compartment cardiovascular model. Vascular resistance, heart rate, and stroke volume values were adopted from literature, while compartmental volumes and compliances were derived from impedance plethysmography of subjects (n=8) riding on a centrifuge. Three different models were developed to represent the typical male subject who completed a 10-min postflight stand test ("male finisher"), "non-finishing male" and "female" (all non-finishers). A sensitivity analysis found that both cardiac output and arterial pressure were most sensitive to total blood volume. Simulated stand tests showed that female astronauts were more susceptible to orthostatic intolerance due to lower initial blood pressure and higher pressure threshold for presyncope. Rates of blood volume loss by capillary filtration were found to be equivalent in female and male non-finishers, but four times smaller in male finishers. For equivalent times to presyncope during centrifugation as those during constant gravity, lower G forces at the level of the heart were required. Centrifuge G levels to match other cardiovascular parameters varied depending on the parameter, centrifuge arm length, and the gravity level being matched.
Kuys, Suzanne; Brauer, Sandra; Ada, Louise
2006-12-01
Cardiorespiratory fitness is increasingly being recognized as an impairment requiring physiotherapy intervention after stroke. The present study seeks to investigate if routine physiotherapy treatment is capable of inducing a cardiorespiratory training effect and if stroke patients attending physiotherapy who are unable to walk experience less cardiorespiratory stress during physiotherapy when compared to those who are able to walk. A descriptive, observational study, with heart rate monitoring and video-recording of physiotherapy rehabilitation, was conducted. Thirty consecutive stroke patients from a geriatric and rehabilitation unit of a tertiary metropolitan hospital, admitted for rehabilitation, and requiring physiotherapy were included in the study. The main measures of the study were duration (time) and intensity (percentage of heart rate reserve) of standing and walking activities during physiotherapy rehabilitation for non-walking and walking stroke patients. Stroke patients spent an average of 21 minutes participating in standing and walking activities that were capable of inducing a cardiorespiratory training effect. Stroke patients who were able to walk spent longer in these activities during physiotherapy rehabilitation than non-walking stroke patients (p < 0.05). An average intensity of 24% heart rate reserve (HRR) during standing and walking activities was insufficient to result in a cardiorespiratory training effect, with a maximum of 35% achieved for the stroke patients able to walk and 30% for those unable to walk. Routine physiotherapy rehabilitation had insufficient duration and intensity to result in a cardiorespiratory training effect in our group of stroke patients.
Monahan, Ken; Lenihan, Daniel; Brittain, Evan L; Saliba, Linda; Piana, Robert N; Robison, Leslie L; Hudson, Melissa M; Armstrong, Gregory T
2018-05-14
Pulmonary transit time (PTT) obtained from contrast echocardiography is a marker of global cardiopulmonary function. Pulmonary blood volume (PBV), derived from PTT, may be a noninvasive surrogate for left-sided filling pressures, such as pulmonary artery wedge pressure (PAWP). We sought to assess the relationship between PBV obtained from contrast echocardiography and PAWP. Participants were adult survivors of childhood cancer that had contrast echocardiography performed nearly simultaneously with right-heart catheterization. PTT was derived from time-intensity curves of contrast passage through the right ventricle (RV) and left atrium (LA). PBV relative to overall stroke volume (rPBV) was estimated from the product of PTT and heart rate during RV-LA transit. PAWP was obtained during standard right-heart catheterization. The Spearman correlation coefficient was used to assess the relationship between rPBV and PAWP. The study population consisted of 7 individuals who had contrast echocardiography and right-heart catheterization within 3 hours of each other. There was a wide range of right atrial (1-17 mm Hg), mean pulmonary artery (18-42 mm Hg), and PAW pressures (4-26 mm Hg) as well as pulmonary vascular resistance (<1-6 Wood Units). We observed a statistically significant correlation between rPBV and PAWP (r = .85; P = .02). Relative PBV derived from contrast echocardiography correlates with PAWP. If validated in larger studies, rPBV could potentially be used as an alternative to invasively determine left-sided filling pressure. © 2018 Wiley Periodicals, Inc.
Aquatic therapies in patients with compromised left ventricular function and heart failure.
Meyer, Katharina; Leblanc, Marie-Claude
2008-01-01
With water immersion, gravity is partly eliminated, and the water exerts a pressure on the body surface. Consequently there is a blood volume shift from the periphery to the central circulation, resulting in marked volume loading of the thorax and heart. This paper presents a selection of published literature on water immersion, balneotherapy, aqua exercises, and swimming, in patients with left ventricular dysfunction (LVD) and/or stable chronic heart failure (CHF). Based on exploratory studies, central hemodynamic and neurohumoral responses of aquatic therapies will be illustrated. Major findings are: 1. In LVD and CHF, a positive effect of therapeutic warm-water tub bathing has been observed, which is assumed to be from afterload reduction due to peripheral vasodilatation caused by the warm water. 2. In coronary patients with LVD, at low-level water cycling the heart is working more efficiently than at lowlevel cycling outside of water. 3. In patients with previous extensive myocardial infarction, upright immersion to the neck resulted in temporary pathological increases in mean pulmonary artery pressure (mPAP) and mean pulmonary capillary pressures (mPCP). 4. Additionally, during slow swimming (20-25m/min) the mPAP and/or PCP were higher than during supine cycling outside water at a 100W load. 5. In CHF patients, neck- deep immersion resulted in a decrease or no change in stroke volume. 6. Although patients are hemodynamically compromised, they usually maintain a feeling of well-being during aquatic therapy. Based on these findings, clinical indications for aquatic therapies are proposed and ideas are presented to provoke further research.
Genetics of ischaemic stroke; single gene disorders.
Flossmann, Enrico
2006-08-01
Examples of single gene disorders have been described for all major subtypes of ischaemic stroke: accelerated atherosclerosis and subsequent thrombo-embolism (e.g. homocysteinuria), weakening of connective tissue resulting in arterial dissections (e.g. Ehler-Danlos type IV), disorders of cerebral small vessels (e.g. cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and the collagen COL4A1 mutation), disorders increasing the thrombogenic potential of the heart through affecting the myocardium or the heart valves or through disturbance of the heart rhythm (e.g. hypertrophic cardiomyopathy), mitochondrial cytopathies increasing cerebral tissue susceptibility to insults (e.g. mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes), and finally disorders of coagulation that can either directly cause stroke or act synergistically with the aforementioned abnormalities (e.g. sickle cell disease). Most of these disorders are rare but they are important to consider particularly in young patients with stroke, those with a family history or those who have other characteristics of a particular syndrome.
Amarenco, Pierre; Goldstein, Larry B; Sillesen, Henrik; Benavente, Oscar; Zweifler, Richard M; Callahan, Alfred; Hennerici, Michael G; Zivin, Justin A; Welch, K Michael A
2010-03-01
Noncoronary forms of atherosclerosis (including transient ischemic attacks or stroke of carotid origin or >50% stenosis of the carotid artery) are associated with a 10-year vascular risk of >20% and are considered as a coronary heart disease (CHD) -risk equivalent from the standpoint of lipid management. The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial included patients with stroke or transient ischemic attack and no known CHD regardless of the presence of carotid atherosclerosis. We evaluated the risk of developing clinically recognized CHD in SPARCL patients. A total of 4731 patients (mean age, 63 years) was randomized to 80 mg/day atorvastatin placebo. The rates of major coronary event, any CHD event, and any revascularization procedure were evaluated. After 4.9 years of follow-up, the risks of a major coronary event and of any CHD end point in the placebo group were 5.1% and 8.6%, respectively. The rate of outcome of stroke decreased over time, whereas the major coronary event rate was stable. Relative to those having a large vessel-related stroke at baseline, those having a transient ischemic attack, hemorrhagic stroke, small vessel stroke, or a stroke of unknown cause had similar absolute rates for a first major coronary event and for any CHD event; transient ischemic attack, small vessel, and unknown cause groups had lower absolute revascularization procedure rates. Major coronary event, any CHD event, and any revascularization procedure rates were similarly reduced in all baseline stroke subtypes in the atorvastatin arm compared with placebo with no heterogeneity between groups. CHD risk can be substantially reduced by atorvastatin therapy in patients with recent stroke or transient ischemic attack regardless of stroke subtype.
Bennion, Douglas M; Jones, Chad H; Donnangelo, Lauren L; Graham, Justin T; Isenberg, Jacob D; Dang, Alex N; Rodriguez, Vermali; Sinisterra, Ruben D M; Sousa, Frederico B; Santos, Robson A S; Sumners, Colin
2018-06-01
What is the central question of this study? Angiotensin-(1-7) decreases cerebral infarct volume and improves neurological function when delivered centrally before and during ischaemic stroke. Here, we assessed the neuroprotective effects of angiotensin-(1-7) when delivered orally post-stroke. What is the main finding and its importance? We show that oral delivery of angiotensin-(1-7) attenuates cerebral damage induced by middle cerebral artery occlusion in rats, without affecting blood pressure or cerebral blood flow. Importantly, these treatments begin post-stroke at times coincident with the treatment window for tissue plasminogen activator, providing supporting evidence for clinical translation of this new therapeutic strategy. As a target for stroke therapies, the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas [ACE2/Ang-(1-7)/Mas] axis of the renin-angiotensin system can be activated chronically to induce neuroprotective effects, in opposition to the deleterious effects of angiotensin II via its type 1 receptor. However, more clinically relevant treatment protocols with Ang-(1-7) that involve its systemic administration beginning after the onset of ischaemia have not been tested. In this study, we tested systemic post-stroke treatments using a molecule where Ang-(1-7) is included within hydroxypropyl-β-cyclodextrin [HPβCD-Ang-(1-7)] as an orally bioavailable treatment. In three separate protocols, HPβCD-Ang-(1-7) was administered orally to Sprague-Dawley rats after induction of ischaemic stroke by endothelin-1-induced middle cerebral artery occlusion: (i) to assess its effects on cerebral damage and behavioural deficits; (ii) to determine its effects on cardiovascular parameters; and (iii) to determine whether it altered cerebral blood flow. The results indicate that post-stroke oral administration of HPβCD-Ang-(1-7) resulted in 25% reductions in cerebral infarct volumes and improvement in neurological functions (P < 0.05), without inducing any alterations in blood pressure, heart rate or cerebral blood flow. In conclusion, Ang-(1-7) treatment using an oral formulation after the onset of ischaemia induces significant neuroprotection in stroke and might represent a viable approach for taking advantage of the protective ACE2/Ang-(1-7)/Mas axis in this disease. © 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.
Lataro, Renata M; Silva, Carlos A A; Fazan, Rubens; Rossi, Marcos A; Prado, Cibele M; Godinho, Rosely O; Salgado, Helio C
2013-10-15
Heart failure (HF) is characterized by elevated sympathetic activity and reduced parasympathetic control of the heart. Experimental evidence suggests that the increase in parasympathetic function can be a therapeutic alternative to slow HF evolution. The parasympathetic neurotransmission can be improved by acetylcholinesterase inhibition. We investigated the long-term (4 wk) effects of the acetylcholinesterase inhibitor pyridostigmine on sympathovagal balance, cardiac remodeling, and cardiac function in the onset of HF following myocardial infarction. Myocardial infarction was elicited in adult male Wistar rats. After 4 wk of pyridostigmine administration, per os, methylatropine and propranolol were used to evaluate the cardiac sympathovagal balance. The tachycardic response caused by methylatropine was considered to be the vagal tone, whereas the bradycardic response caused by propranolol was considered to be the sympathetic tone. In conscious HF rats, pyridostigmine reduced the basal heart rate, increased vagal, and reduced sympathetic control of heart rate. Pyridostigmine reduced the myocyte diameter and collagen density of the surviving left ventricle. Pyridostigmine also increased vascular endothelial growth factor protein in the left ventricle, suggesting myocardial angiogenesis. Cardiac function was assessed by means of the pressure-volume conductance catheter system. HF rats treated with pyridostigmine exhibited a higher stroke volume, ejection fraction, cardiac output, and contractility of the left ventricle. It was demonstrated that the long-term administration of pyridostigmine started right after coronary artery ligation augmented cardiac vagal and reduced sympathetic tone, attenuating cardiac remodeling and left ventricular dysfunction during the progression of HF in rats.
Goo, Hyun Woo
2017-12-01
Accurate evaluation of anatomy and ventricular function after the Norwood procedure in hypoplastic left heart syndrome is important for treatment planning and prognostication, but echocardiography and cardiac MRI have limitations. To assess serial changes in anatomy and ventricular function on dual-source cardiac CT after the Norwood procedure for hypoplastic left heart syndrome. In 14 consecutive patients with hypoplastic left heart syndrome, end-systolic and end-diastolic phase cardiac dual-source CT was performed before and early (average: 1 month) after the Norwood procedure, and repeated late (median: 4.5 months) after the Norwood procedure in six patients. Ventricular functional parameters and indexed morphological measurements including pulmonary artery size, right ventricular free wall thickness, and ascending aorta size on cardiac CT were compared between different time points. Moreover, morphological features including ventricular septal defect, endocardial fibroelastosis and coronary ventricular communication were evaluated on cardiac CT. Right ventricular function and volumes remained unchanged (indexed end-systolic and end-diastolic volumes: 38.9±14.0 vs. 41.1±21.5 ml/m 2 , P=0.7 and 99.5±30.5 vs. 105.1±33.0 ml/m 2 , P=0.6; ejection fraction: 60.1±7.3 vs. 63.8±7.0%, P=0.1, and indexed stroke volume: 60.7±18.0 vs. 64.0±15.6 ml/m 2 , P=0.5) early after the Norwood procedure, but function was decreased (ejection fraction: 64.2±2.6 vs. 58.1±7.1%, P=0.01) and volume was increased (indexed end-systolic and end-diastolic volumes: 39.2±14.9 vs. 68.9±20.6 ml/m 2 , P<0.003 and 107.8±36.5 vs. 162.9±36.2 ml/m 2 , P<0.006, and indexed stroke volume: 68.6±21.7 vs. 94.0±21.3 ml/m 2 , P=0.02) later. Branch pulmonary artery size showed a gradual decrease without asymmetry after the Norwood procedure. Right and left pulmonary artery stenoses were identified in 21.4% (3/14) of the patients. Indexed right ventricular free wall thickness showed a significant increase early after the Norwood procedure (25.5±3.5 vs. 34.8±5.1 mm/m 2 , P=0.01) and then a significant decrease late after the Norwood procedure (34.8±5.1 vs. 27.2±4.2 mm/m 2 , P<0.0001). The hypoplastic ascending aorta smaller than 2 mm in diameter was identified in 21.4% (3/14) of the patients. Ventricular septal defect (n=3), endocardial fibroelastosis (n=2) and coronary ventricular communication (n=1) were detected on cardiac CT. Cardiac CT can be used to assess serial changes in anatomy and ventricular function after the Norwood procedure in patients with hypoplastic left heart syndrome.
Continuous-flow cardiac assistance: effects on aortic valve function in a mock loop.
Tuzun, Egemen; Rutten, Marcel; Dat, Marco; van de Vosse, Frans; Kadipasaoglu, Cihan; de Mol, Bas
2011-12-01
As the use of left ventricular assist devices (LVADs) to treat end-stage heart failure has become more widespread, leaflet fusion--with resul-tant aortic regurgitation--has been observed more frequently. To quantitatively assess the effects of nonpulsatile flow on aortic valve function, we tested a continuous-flow LVAD in a mock circulatory system (MCS) with an interposed valve. To mimic the hemodynamic characteristics of LVAD patients, we utilized an MCS in which a Jarvik 2000 LVAD was positioned at the base of a servomotor-operated piston pump (left ventricular chamber). We operated the LVAD at 8000 to 12,000 rpm, changing the speed in 1000-rpm increments. At each speed, we first varied the outflow resistance at a constant stroke volume, then varied the stroke volume at a constant outflow resistance. We measured the left ventricular pressure, aortic pressure, pump flow, and total flow, and used these values to compute the change, if any, in the aortic duty cycle (aortic valve open time) and transvalvular aortic pressure loads. Validation of the MCS was demonstrated by the simulation of physiologic pressure and flow waveforms. At increasing LVAD speeds, the mean aortic pressure load steadily increased, while the aortic duty cycle steadily decreased. Changes were consistent for each MCS experimental setting, despite variations in stroke volume and outflow resistance. Increased LVAD flow results in an impaired aortic valve-open time due to a pressure overload above the aortic valve. Such an overload may initiate structural changes, causing aortic leaflet fusion and/or regurgitation. Copyright © 2011 Elsevier Inc. All rights reserved.
Time-Dependent Computed Tomographic Perfusion Thresholds for Patients With Acute Ischemic Stroke.
d'Esterre, Christopher D; Boesen, Mari E; Ahn, Seong Hwan; Pordeli, Pooneh; Najm, Mohamed; Minhas, Priyanka; Davari, Paniz; Fainardi, Enrico; Rubiera, Marta; Khaw, Alexander V; Zini, Andrea; Frayne, Richard; Hill, Michael D; Demchuk, Andrew M; Sajobi, Tolulope T; Forkert, Nils D; Goyal, Mayank; Lee, Ting Y; Menon, Bijoy K
2015-12-01
Among patients with acute ischemic stroke, we determine computed tomographic perfusion (CTP) thresholds associated with follow-up infarction at different stroke onset-to-CTP and CTP-to-reperfusion times. Acute ischemic stroke patients with occlusion on computed tomographic angiography were acutely imaged with CTP. Noncontrast computed tomography and magnectic resonance diffusion-weighted imaging between 24 and 48 hours were used to delineate follow-up infarction. Reperfusion was assessed on conventional angiogram or 4-hour repeat computed tomographic angiography. Tmax, cerebral blood flow, and cerebral blood volume derived from delay-insensitive CTP postprocessing were analyzed using receiver-operator characteristic curves to derive optimal thresholds for combined patient data (pooled analysis) and individual patients (patient-level analysis) based on time from stroke onset-to-CTP and CTP-to-reperfusion. One-way ANOVA and locally weighted scatterplot smoothing regression was used to test whether the derived optimal CTP thresholds were different by time. One hundred and thirty-two patients were included. Tmax thresholds of >16.2 and >15.8 s and absolute cerebral blood flow thresholds of <8.9 and <7.4 mL·min(-1)·100 g(-1) were associated with infarct if reperfused <90 min from CTP with onset <180 min. The discriminative ability of cerebral blood volume was modest. No statistically significant relationship was noted between stroke onset-to-CTP time and the optimal CTP thresholds for all parameters based on discrete or continuous time analysis (P>0.05). A statistically significant relationship existed between CTP-to-reperfusion time and the optimal thresholds for cerebral blood flow (P<0.001; r=0.59 and 0.77 for gray and white matter, respectively) and Tmax (P<0.001; r=-0.68 and -0.60 for gray and white matter, respectively) parameters. Optimal CTP thresholds associated with follow-up infarction depend on time from imaging to reperfusion. © 2015 American Heart Association, Inc.
Effects of thyroid hormones on the heart.
Vargas-Uricoechea, Hernando; Bonelo-Perdomo, Anilsa; Sierra-Torres, Carlos Hernán
2014-01-01
Thyroid hormones have a significant impact on heart function, mediated by genomic and non-genomic effects. Consequently, thyroid hormone deficiencies, as well as excesses, are expected to result in profound changes in cardiac function regulation and cardiovascular hemodynamics. Thyroid hormones upregulate the expression of the sarcoplasmic reticulum calcium-activated ATPase and downregulate the expression of phospholamban. Overall, hyperthyroidism is characterized by an increase in resting heart rate, blood volume, stroke volume, myocardial contractility, and ejection fraction. The development of "high-output heart failure" in hyperthyroidism may be due to "tachycardia-mediated cardiomyopathy". On the other hand, in a hypothyroid state, thyroid hormone deficiency results in lower heart rate and weakening of myocardial contraction and relaxation, with prolonged systolic and early diastolic times. Cardiac preload is decreased due to impaired diastolic function. Cardiac afterload is increased, and chronotropic and inotropic functions are reduced. Subclinical thyroid dysfunction is relatively common in patients over 65 years of age. In general, subclinical hypothyroidism increases the risk of coronary heart disease (CHD) mortality and CHD events, but not of total mortality. The risk of CHD mortality and atrial fibrillation (but not other outcomes) in subclinical hyperthyroidism is higher among patients with very low levels of thyrotropin. Finally, medications such as amiodarone may induce hypothyroidism (mediated by the Wolff-Chaikoff), as well as hyperthyroidism (mediated by the Jod-Basedow effect). In both instances, the underlying cause is the high concentration of iodine in this medication. Copyright © 2014 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.
Aerobic power and flight capacity in birds: a phylogenetic test of the heart-size hypothesis.
Nespolo, Roberto F; González-Lagos, César; Solano-Iguaran, Jaiber J; Elfwing, Magnus; Garitano-Zavala, Alvaro; Mañosa, Santiago; Alonso, Juan Carlos; Altimiras, Jordi
2018-01-09
Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level. © 2018. Published by The Company of Biologists Ltd.
Warriner, David R; Brown, Alistair G; Varma, Susheel; Sheridan, Paul J; Lawford, Patricia; Hose, David R; Al-Mohammad, Abdallah; Shi, Yubing
2014-01-01
The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models. A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax). For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.
Schaapsmeerders, Pauline; van Uden, Inge W M; Tuladhar, Anil M; Maaijwee, Noortje A M; van Dijk, Ewoud J; Rutten-Jacobs, Loes C A; Arntz, Renate M; Schoonderwaldt, Hennie C; Dorresteijn, Lucille D A; de Leeuw, Frank-Erik; Kessels, Roy P C
2015-07-01
Memory impairment after stroke in young adults is poorly understood. In elderly stroke survivors memory impairments and the concomitant loss of hippocampal volume are usually explained by coexisting neurodegenerative disease (e.g., amyloid pathology) in interaction with stroke. However, neurodegenerative disease, such as amyloid pathology, is generally absent at young age. Accumulating evidence suggests that infarction itself may cause secondary neurodegeneration in remote areas. Therefore, we investigated the relation between long-term memory performance and hippocampal volume in young patients with first-ever ischemic stroke. We studied all consecutive first-ever ischemic stroke patients, aged 18-50 years, admitted to our academic hospital center between 1980 and 2010. Episodic memory of 173 patients was assessed using the Rey Auditory Verbal Learning Test and the Rey Complex Figure and compared with 87 stroke-free controls. Hippocampal volume was determined using FSL-FIRST, with manual correction. On average 10 years after stroke, patients had smaller ipsilateral hippocampal volumes compared with controls after left-hemispheric stroke (5.4%) and right-hemispheric stroke (7.7%), with most apparent memory dysfunctioning after left-hemispheric stroke. A larger hemispheric stroke was associated with a smaller ipsilateral hippocampal volume (b=-0.003, P<0.0001). Longer follow-up duration was associated with smaller ipsilateral hippocampal volume after left-hemispheric stroke (b=-0.028 ml, P=0.002) and right-hemispheric stroke (b=-0.015 ml, P=0.03). Our results suggest that infarction is associated with remote injury to the hippocampus, which may lower or expedite the threshold for cognitive impairment or even dementia later in life. © 2015 Wiley Periodicals, Inc.
Beat-by-beat stroke volume assessment by pulsed Doppler in upright and supine exercise
NASA Technical Reports Server (NTRS)
Loeppky, J. A.; Greene, E. R.; Hoekenga, D. E.; Caprihan, A.; Luft, U. C.
1981-01-01
The instantaneous stroke volume (SV) and cardiac output (Q) in eight male subjects during steady-state supine (S) and upright (U) exercises at 300 kpm/min is assessed by a 3.0-MHz pulsed Doppler echocardiograph. The mean transients in heart rate (HR), SV, and Q for each posture were determined and the center-line blood velocities obtained in the ascending aorta. Results show that the mean supine values for SV and Q at rest and exercise were 111 ml and 6.4 l/min and 112 ml and 9.7 l/min, respectively. The corresponding results for U were 76 ml and 5.6 l/min and 92 ml and 8.4 l/min, respectively. The values compare favorably with previous studies utilizing invasive procedures. The transient response of Q following the onset of exercise in U was about twice as fast as in S because of the rapid and almost immediate upsurge in SV. The faster rise in aortic flow in U with exercise represented and additional volume (184 ml) of blood passing through the aorta compared with S in the first 20 exercises. It is suggested that the rapid mobilization of pooled venous blood from the leg veins during U was responsible for the increased blood flow.
Kernan, Walter N; Ovbiagele, Bruce; Black, Henry R; Bravata, Dawn M; Chimowitz, Marc I; Ezekowitz, Michael D; Fang, Margaret C; Fisher, Marc; Furie, Karen L; Heck, Donald V; Johnston, S Claiborne Clay; Kasner, Scott E; Kittner, Steven J; Mitchell, Pamela H; Rich, Michael W; Richardson, DeJuran; Schwamm, Lee H; Wilson, John A
2014-07-01
The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines. © 2014 American Heart Association, Inc.
Morrison, Alanna C; Bare, Lance A; Luke, May M; Pankow, James S; Mosley, Thomas H; Devlin, James J; Willerson, James T; Boerwinkle, Eric
2008-01-01
Ischemic stroke and coronary heart disease (CHD) may share genetic factors contributing to a common etiology. This study investigates whether 51 single nucleotide polymorphisms (SNPs) associated with CHD in multiple antecedent studies are associated with incident ischemic stroke in the Atherosclerosis Risk in Communities (ARIC) study. From the multiethnic ARIC cohort of 14,215 individuals, 495 validated ischemic strokes were identified. Cox proportional hazards models, adjusted for age and gender, identified three SNPs in Whites and two SNPs in Blacks associated with incident stroke (p
Equilibrium radionuclide gated angiography in patients with tricuspid regurgitation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Handler, B.; Pavel, D.G.; Pietras, R.
Equilibrium gated radionuclide angiography was performed in 2 control groups (15 patients with no organic heart disease and 24 patients with organic heart disease but without right- or left-sided valvular regurgitation) and in 9 patients with clinical tricuspid regurgitation. The regurgitant index, or ratio of left to right ventricular stroke counts, was significantly lower in patients with tricuspid regurgitation than in either control group. Time-activity variation over the liver was used to compute a hepatic expansion fraction which was significantly higher in patients with tricuspid regurgitation than in either control group. Fourier analysis of time-activity variation in each pixel wasmore » used to generate amplitude and phase images. Only pixels with values for amplitude at least 7% of the maximum in the image were retained in the final display. All patients with tricuspid regurgitation had greater than 100 pixels over the liver automatically retained by the computer. These pixels were of phase comparable to that of the right atrium and approximately 180 degrees out of phase with the right ventricle. In contrast, no patient with no organic heart disease and only 1 of 24 patients with organic heart disease had any pixels retained by the computer. In conclusion, patients with tricuspid regurgitation were characterized on equilibrium gated angiography by an abnormally low regurgitant index (7 of 9 patients) reflecting increased right ventricular stroke volume, increased hepatic expansion fraction (7 of 9 patients), and increased amplitude of count variation over the liver in phase with the right atrium (9 of 9 patients).« less
Honda, N; Inamoto, T; Nogawa, M; Takatani, S
1999-03-01
An ultracompact, completely implantable permanent use electromechanical ventricular assist device (VAD) and total artificial heart (TAH) intended for 50-60 kg size patients have been developed. The TAH and VAD share a miniature electromechanical actuator that comprises a DC brushless motor and a planetary roller screw. The rotational force of the motor is converted into the rectilinear force of the roller screw to actuate the blood pump. The TAH is a one piece design with left and right pusher plate type blood pumps sandwiching an electromechanical actuator. The VAD is one half of the TAH with the same actuator but a different pump housing and a backplate. The blood contacting surfaces, including those of the flexing diaphragm and pump housing, of both the VAD and TAH were made of biocompatible polyurethane. The diameter, thickness, volume, and weight of the VAD are 90 mm, 56 mm, 285 cc, and 380 g, respectively, while those of the TAH are 90 mm, 73 mm, 400 cc, and 440 g, respectively. The design stroke volume of both the VAD and TAH is 60 cc with the stroke length being 12 mm. The stroke length and motor speed are controlled solely based on the commutation signals of the motor. An in vitro study revealed that a maximum pump flow of 7.5 L/min can be obtained with a pump rate of 140 bpm against a mean afterload of 100 mm Hg. The power requirement ranged from 4 to 6 W to deliver a 4-5 L/min flow against a 100 mm Hg afterload with the electrical-to-hydraulic efficiency being 19-20%. Our VAD and TAH are the smallest of the currently available devices and suitable for bridge to transplant application as well as for permanent circulatory support of 50-60 kg size patients.
Kim, Nam Hoon; Kwon, Tae Yeon; Yu, Sungwook; Kim, Nan Hee; Choi, Kyung Mook; Baik, Sei Hyun; Park, Yousung; Kim, Sin Gon
2017-04-01
Prediabetes is a known risk factor for vascular diseases; however, its differential contribution to mortality risk from various vascular disease subtypes is not known. The subjects of the National Health Insurance Service in Korea (2002-2013) nationwide cohort were stratified into normal glucose tolerance (fasting glucose <100 mg/dL), impaired fasting glucose (IFG) stage 1 (100-109 mg/dL), IFG stage 2 (110-125 mg/dL), and diabetes mellitus groups based on the fasting glucose level. A Cox regression analysis with counting process formulation was used to assess the mortality risk for vascular disease and its subtypes-ischemic heart disease, ischemic stroke, and hemorrhagic stroke. When adjusted for age, sex, and body mass index, IFG stage 2, but not stage 1, was associated with significantly higher all-cause mortality (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.18-1.34) and vascular disease mortality (HR, 1.27; 95% CI, 1.08-1.49) compared with normal glucose tolerance. Among the vascular disease subtypes, mortality from ischemic stroke was significantly higher (HR, 1.60; 95% CI, 1.18-2.18) in subjects with IFG stage 2 but not from ischemic heart disease and hemorrhagic stroke. The ischemic stroke mortality associated with IFG stage 2 remained significantly high when adjusted other modifiable vascular disease risk factors (HR, 1.51; 95% CI: 1.10-2.09) and medical treatments (HR, 1.75; 95% CI, 1.19-2.57). Higher IFG degree (fasting glucose, 110-125 mg/dL) was associated with increased all-cause and vascular disease mortality. The increased vascular disease mortality in IFG stage 2 was attributable to ischemic stroke, but not ischemic heart disease or hemorrhagic stroke in Korean adults. © 2017 American Heart Association, Inc.
Andrade, A; Nicolosi, D; Lucchi, J; Biscegli, J; Arruda, A C; Ohashi, Y; Mueller, J; Tayama, E; Glueck, J; Nosé, Y
1999-09-01
Leading international institutions are designing and developing various types of ventricular assist devices (VAD) and total artificial hearts (TAH). Some of the commercially available pulsatile VADs are not readily implantable into the thoracic cavity of smaller size patients because of size limitation. The majority of the TAH dimensions requires the removal of the patients' native heart. A miniaturized artificial heart, the auxiliary total artificial heart (ATAH), is being developed in these authors' laboratories. This device is an electromechanically driven ATAH using a brushless direct current (DC) motor fixed in a center metallic piece. This pusher plate-type ATAH control is based on Frank-Starling's law. The beating frequency is regulated through the change of the left preload, assisting the native heart in obtaining adequate blood flow. With the miniaturization of this pump, the average sized patient can have the surgical implantation procedure in the right thoracic cavity without removing the native heart. The left and right stroke volumes are 35 and 32 ml, respectively. In vitro tests were conducted, and the performance curves demonstrate that the ATAH produces 5 L/min of cardiac output at 180 bpm (10 mmHg of left inlet mean pressure and 100 mm Hg of left outlet mean pressure). Taking into account that this ATAH is working along with the native heart, this output is more than satisfactory for such a device.
Fluid therapy and the hypovolemic microcirculation.
Gruartmoner, G; Mesquida, J; Ince, Can
2015-08-01
In shock states, optimizing intravascular volume is crucial to promote an adequate oxygen delivery to the tissues. Our current practice in fluid management pivots on the Frank-Starling law of the heart, and the effects of fluids are measured according to the induced changes on stroke volume. The purpose of this review is to evaluate the boundaries of current macrohemodynamic approach to fluid administration, and to introduce the microcirculatory integration as a fundamental part of tissue perfusion monitoring. Macrocirculatory changes induced by volume expansion are not always coupled to proportional changes in microcirculatory perfusion. Loss of hemodynamic coherence limits the value of guiding fluid therapy according to macrohemodynamics, and highlights the importance of evaluating the ultimate target of volume administration, the microcirculation. Current approach to intravascular volume optimization is made from a macrohemodynamic perspective. However, several situations wherein macrocirculatory and microcirculatory coherence is lost have been described. Future clinical trials should explore the usefulness of integrating the microcirculatory evaluation in fluid optimization.
Dozois, Adeline; Hampton, Lorrie; Kingston, Carlene W; Lambert, Gwen; Porcelli, Thomas J; Sorenson, Denise; Templin, Megan; VonCannon, Shellie; Asimos, Andrew W
2017-12-01
The recently proposed American Heart Association/American Stroke Association EMS triage algorithm endorses routing patients with suspected large vessel occlusion (LVO) acute ischemic strokes directly to endovascular centers based on a stroke severity score. The predictive value of this algorithm for identifying LVO is dependent on the overall prevalence of LVO acute ischemic stroke in the EMS population screened for stroke, which has not been reported. We performed a cross-sectional study of patients transported by our county's EMS agency who were dispatched as a possible stroke or had a primary impression of stroke by paramedics. We determined the prevalence of LVO by reviewing medical record imaging reports based on a priori specified criteria. We enrolled 2402 patients, of whom 777 (32.3%) had an acute stroke-related diagnosis. Among 485 patients with acute ischemic stroke, 24.1% (n=117) had an LVO, which represented only 4.87% (95% confidence interval, 4.05%-5.81%) of the total EMS population screened for stroke. Overall, the prevalence of LVO acute ischemic stroke in our EMS population screened for stroke was low. This is an important consideration for any EMS stroke severity-based triage protocol and should be considered in predicting the rates of overtriage to endovascular stroke centers. © 2017 American Heart Association, Inc.
Berger, Benjamin; Gumbinger, Christoph; Steiner, Thorsten; Sykora, Marek
2014-04-01
Because of the immune-suppressive effect of cerebral damage, stroke patients are at high risk for infections. These might result in sepsis, which is the major contributor to intensive care unit (ICU) mortality. Although there are numerous studies on infections in stroke patients, the role of sepsis as a poststroke complication is unknown. We retrospectively analyzed incidence of and risk factors for sepsis acquisition as well as outcome parameters of 238 patients with ischemic or hemorrhagic strokes consecutively admitted to the neurologic ICU in a tertiary university hospital between January 1, 2009, and December 31, 2010. Basic demographic and clinical data including microbiological parameters as well as factors describing stroke severity (eg, lesion volume and National Institute of Health stroke scale score) were recorded and included into the analysis. The diagnosis of sepsis was based on the criteria of the German Sepsis Society. We identified 30 patients (12.6%) with sepsis within the first 7 days from stroke onset. The lungs were the most frequent source of infection (93.3%), and gram-positive organisms were dominating the microbiologic spectrum (52.4%). Comorbidities (chronic obstructive pulmonary disease and immunosuppressive disorders) and Simplified Acute Physiology Score II but none of the factors describing stroke severity were independent predictors of sepsis acquisition. Sepsis was associated with a significantly worse prognosis, leading to a 2-fold increased mortality rate during in-hospital care (36.7% vs 18.8%) and after 3 months (56.5% vs 28.5%), but only in the subgroup of supratentorial hemorrhages, it was an independent predictor of in-hospital and 3-month mortality. Other factors significantly associated with death in a multivariate analysis were chronic obstructive pulmonary disease, malignancies (in-hospital mortality only), and Simplified Acute Physiology Score II (3-month mortality only) for ischemia and heart failure (in-hospital mortality only), National Institute of Health stroke scale score (in-hospital mortality only), and stroke volume for hemorrhages, respectively. Sepsis seems to be a frequent complication of stroke patients requiring neurologic ICU treatment. Predictors of sepsis acquisition in our study were comorbidities and severity of deterioration of physiological status, but not stroke severity. A better understanding of risk factors is important for prevention and early recognition, whereas knowledge of outcome may help in prognosis prediction. Further studies are needed to clarify the optimal preventive treatment for these patients. Copyright © 2014 Elsevier Inc. All rights reserved.
Jørgensen, Torben; Jacobsen, Rikke Kart; Toft, Ulla; Aadahl, Mette; Glümer, Charlotte; Pisinger, Charlotta
2014-06-09
To investigate the effect of systematic screening for risk factors for ischaemic heart disease followed by repeated lifestyle counselling on the 10 year development of ischaemic heart disease at a population level. Randomised controlled community based trial. Suburbs of Copenhagen, Denmark. 59,616 people aged 30-60 years randomised with different age and sex randomisation ratios to an intervention group (n = 11,629) and a control group (n = 47,987). The intervention group was invited for screening, risk assessment, and lifestyle counselling up to four times over a five year period. All participants with an unhealthy lifestyle had individually tailored lifestyle counselling at all visits (at baseline and after one and three years); those at high risk of ischaemic heart disease, according to predefined criteria, were furthermore offered six sessions of group based lifestyle counselling on smoking cessation, diet, and physical activity. After five years all were invited for a final counselling session. Participants were referred to their general practitioner for medical treatment, if relevant. The control group was not invited for screening. The primary outcome measure was incidence of ischaemic heart disease in the intervention group compared with the control group. Secondary outcome measures were stroke, combined events (ischaemic heart disease, stroke, or both), and mortality. 6091 (52.4%) people in the intervention group participated at baseline. Among 5978 people eligible at five year follow-up (59 died and 54 emigrated), 4028 (67.4%) attended. A total of 3163 people died in the 10 year follow-up period. Among 58,308 without a history of ischaemic heart disease at baseline, 2782 developed ischaemic heart disease. Among 58,940 without a history of stroke at baseline, 1726 developed stroke. No significant difference was seen between the intervention and control groups in the primary end point (hazard ratio for ischaemic heart disease 1.03, 95% confidence interval 0.94 to 1.13) or in the secondary endpoints (stroke 0.98, 0.87 to 1.11; combined endpoint 1.01, 0.93 to 1.09; total mortality 1.00, 0.91 to 1.09). A community based, individually tailored intervention programme with screening for risk of ischaemic heart disease and repeated lifestyle intervention over five years had no effect on ischaemic heart disease, stroke, or mortality at the population level after 10 years.Trial registration Clinical trials NCT00289237. © Jørgensen et al 2014.
The incidence of ischemic stroke in chronic heart failure: a meta-analysis.
Witt, Brandi J; Gami, Apoor S; Ballman, Karla V; Brown, Robert D; Meverden, Ryan A; Jacobsen, Stephen J; Roger, Véronique L
2007-08-01
There is marked variability in the reported stroke rates among persons with heart failure (HF). We performed a meta-analysis to provide summary estimates of the stroke rate in HF and to explain heterogeneity in the existing literature. We will summarize the ischemic stroke rate at various time points during follow-up among adults with chronic heart failure. A systematic review of the electronic literature in Medline and PubMed as well as hand searching of the reference lists of identified articles and of the meeting abstracts for the 1995-2004 American College of Cardiology and American Heart Association scientific sessions was performed to identify qualifying studies. Articles were included if they included a population with chronic HF and reported the number (or percent) of persons with HF who experienced an ischemic stroke during follow-up. Studies were excluded if the study population included > or = 50% of persons with acute (postmyocardial infarction) HF, or if > or = 50% of the study population required artificial support with a ventricular assist device or parenteral inotropic medications. Case reports, case series, and nonoriginal research articles were not included. Determination of study eligibility and data extraction were conducted by 2 independent reviewers using standardized forms. Results are reported as stroke rate per 1000 cases of HF, with 95% Poisson confidence intervals. Pooled estimates of the stroke rate were calculated with fixed and random effects models. Heterogeneity was explored according to a priori specified subgroup analyses. Overall, 26 studies met inclusion criteria. Eighteen of every 1000 persons suffered a stroke during the first year after the diagnosis of HF. The stroke rate increased to a maximum of 47.4 per 1000 at 5 years. Studies with fewer women, those conducted in 1990 or earlier, and cohort studies reported higher stroke rates than studies with more women, those conducted after 1990, and clinical trials. Stroke is an important complication among persons with HF. Variability among reported stroke rates can be explained in part by differences in study design, patient population, and HF standards of care at the time of the study. Despite the heterogeneity in reported stroke rates, this meta-analysis shows that stroke prevention in HF represents an opportunity to prevent morbidity and save many lives in this highly fatal disease.
Case volumes of intra-arterial and intravenous treatment of ischemic stroke in the USA.
Hirsch, J A; Yoo, A J; Nogueira, R G; Verduzco, L A; Schwamm, L H; Pryor, J C; Rabinov, J D; González, R G
2009-07-01
Ischemic stroke is a major cause of disability and death in the USA. Intravenous tissue plasminogen activator (t-PA) remains underutilized. With the development of newer intra-arterial reperfusion therapies, there is increased opportunity to address the more devastating large-vessel occlusions. We seek to identify the numbers of patients with stroke treated with intravenous and intra-arterial therapies, as well as to estimate the potential number of intra-arterial cases in the foreseeable future. We performed a literature search to determine case volumes of intravenous t-PA use. We extrapolated the current case volume of intra-arterial stroke therapies from the numbers of cases in which the Merci retrieval device was used. In order to estimate the potential numbers of intra-arterial stroke cases, we characterized the percentage of patients with stroke who received intra-arterial therapy at two leading stroke centers. We applied these percentages to the numbers of patients with stroke seen at the top 100, 200 and 500 stroke centers by volume. The rate of intravenous t-PA use is 2.4-3.6%, resulting in 15 000-22 000 cases/year in the USA. The estimated case volume of intra-arterial therapies is 3500-7200 in 2006. Based on data from St. Luke's Brain and Stroke Institute and Massachusetts General Hospital, approximately 5-20% of patients with ischemic stroke can be treated with intra-arterial therapies. Extrapolating this to the top 500 stroke centers by volume, the potential number of intra-arterial cases in the USA is 10 400-41 500/year. Based on the current numbers of intra-arterial cases, our theoretical model identifies a potential for significant growth of this stroke therapy.
Xiong, Li; Tian, Ge; Wang, Li; Lin, Wenhua; Chen, Xiangyan; Leung, Thomas Wai Hong; Soo, Yannie Oi Yan; Wong, Lawrence Ka Sing
2017-07-01
External counterpulsation (ECP) is a noninvasive method used to augment cerebral perfusion in ischemic stroke. However, the response of beat-to-beat heart rate variability (HRV) in patients with ischemic stroke during ECP remains unknown. Forty-eight patients with unilateral ischemic stroke at the subacute stage and 14 healthy controls were recruited. Beat-to-beat heart rate before, during, and after ECP was monitored. The frequency components of HRV were calculated using power spectral analysis. Very low frequency (VLF; <.04 Hz), low frequency (LF; .04-.15 Hz), high frequency (HF; .15-.40 Hz), total power spectral density (TP; <.40 Hz), and LF/HF ratio were calculated. In stroke patients, although there were no statistical differences in all of the HRV components, the HRV at VLF showed a trend of increase during ECP compared with baseline in the left-sided stroke patients (P = .083). After ECP, the HRV at LF and TP remained higher than baseline in the right-sided stroke patients (LF, 209.4 versus 117.9, P = .050; TP, 1275.6 versus 390.2, P = .017, respectively). Besides, the HRV at TP also increased after ECP compared with baseline in the left-sided stroke patients (563.0 versus 298.3, P = .029). Irrespective of the side of the ischemia, patients showed an increased beat-to-beat HRV after ECP. Additionally, sympathetic and parasympathetic cardiac modulations were increased after ECP in patients after right-sided subacute stroke. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Wu, Lingyun; Wang, Anxin; Wang, Xianwei; Zhao, Xingquan; Wang, Chunxue; Liu, Liping; Zheng, Huaguang; Wang, Yongjun; Cao, Yibin; Wang, Yilong
2015-12-09
Stroke recurrence and disability in patients with a minor stroke is one of the most depressing medical situations. In this study, we aimed to identify which factors were associated with adverse outcomes of a minor stroke. The China National Stroke Registry (CNSR) is a nationwide prospective registry for patients presented to hospitals with acute cerebrovascular events between September 2007 and August 2008. The 3-month follow-up was completed in 4669 patients with a minor stroke defined as the initial neurological severity lower than 4 in the National Institutes of Health Stroke Scale (NIHSS). Multivariate model was used to determine the association between risk factors and clinical outcomes. Of 4669 patients with a minor stroke during 3-month follow-up, 459 (9.8 %) patients experienced recurrent stroke, 679 (14.5 %) had stroke disability and 168 (3.6 %) died. Multivariate model identified hypertension, diabetes mellitus, atrial fibrillation, coronary heart disease and previous stroke as independent predictors for the recurrent stroke. Age, diabetes mellitus, atrial fibrillation, previous stroke and time from onset to admission < 24 h were independent predictors for stroke disability. The independent predictors for the all-caused death were age, atrial fibrillation, and coronary heart disease. The short-term risk of poor clinical outcome in Chinese patients with a minor stroke was substantial. Therefore, patients with a minor stroke should be given expeditious assessment and urgent aggressive intervention.
Fonarow, Gregg C; Calitz, Chris; Arena, Ross; Baase, Catherine; Isaac, Fikry W; Lloyd-Jones, Donald; Peterson, Eric D; Pronk, Nico; Sanchez, Eduardo; Terry, Paul E; Volpp, Kevin G; Antman, Elliott M
2015-05-19
The workplace is an important setting for promoting cardiovascular health and cardiovascular disease and stroke prevention in the United States. Well-designed, comprehensive workplace wellness programs have the potential to improve cardiovascular health and to reduce mortality, morbidity, and disability resulting from cardiovascular disease and stroke. Nevertheless, widespread implementation of comprehensive workplace wellness programs is lacking, and program composition and quality vary. Several organizations provide worksite wellness recognition programs; however, there is variation in recognition criteria, and they do not specifically focus on cardiovascular disease and stroke prevention. Although there is limited evidence to suggest that company performance on employer health management scorecards is associated with favorable healthcare cost trends, these data are not currently robust, and further evaluation is needed. As a recognized national leader in evidence-based guidelines, care systems, and quality programs, the American Heart Association/American Stroke Association is uniquely positioned and committed to promoting the adoption of comprehensive workplace wellness programs, as well as improving program quality and workforce health outcomes. As part of its commitment to improve the cardiovascular health of all Americans, the American Heart Association/American Stroke Association will promote science-based best practices for comprehensive workplace wellness programs and establish benchmarks for a national workplace wellness recognition program to assist employers in applying the best systems and strategies for optimal programming. The recognition program will integrate identification of a workplace culture of health and achievement of rigorous standards for cardiovascular health based on Life's Simple 7 metrics. In addition, the American Heart Association/American Stroke Association will develop resources that assist employers in meeting these rigorous standards, facilitating access to high-quality comprehensive workplace wellness programs for both employees and dependents, and fostering innovation and additional research. © 2015 American Heart Association, Inc.
Factors determining case fatality in myocardial infarction "who dies in a heart attack"?
Wannamethee, G; Whincup, P H; Shaper, A G; Walker, M; MacFarlane, P W
1995-09-01
To examine the determinants of case fatality in the first major ischaemic heart disease event (heart attack) after screening. Prospective study of 7735 middle aged men drawn from general practices in 24 British towns. During 11.5 years follow up there were 743 major ischaemic heart disease events of which 302 (40.6%) were fatal within 28 days of onset. Previous definite myocardial infarction or stroke and age at time of event were most strongly associated with case fatality. In men with no previous myocardial infarction or stroke, after adjustment for a range of risk factors, antihypertensive treatment (odds ratio (OR) = 1.97, P < 0.05), arrhythmia (OR = 1.93, P = 0.06), increased heart rate (OR = 2.03, P = 0.06), and diabetes (OR = 2.61, P = 0.07) were associated with increased case fatality. High levels of physical activity (OR = 0.53, P < 0.05) and moderate drinking (16-42 units/week) (OR = 0.61, P < 0.05) were associated with lower case fatality, although moderate drinking was not associated with a lower incidence of major ischaemic heart disease events. Current smoking, serum total cholesterol, and systolic blood pressure were not significantly associated with case fatality. In men with previous myocardial infarction or stroke, arrhythmia and to a lesser degree antihypertensive treatment, moderate or heavy drinking, and diabetes were associated with higher case fatality. These findings suggest that physical activity may be an important modifiable factor influencing the incidence of ischaemic heart disease and the chance of survival in men without a previous heart attack or stroke. Arrhythmia, increased heart rate, diabetes, and treatment for hypertension are also areas of concern.
Tu, Jack V.; Nardi, Lorelei; Fang, Jiming; Liu, Juan; Khalid, Laila; Johansen, Helen
2009-01-01
Background Rates of death from cardiovascular and cerebrovascular diseases have been steadily declining over the past few decades. Whether such declines are occurring to a similar degree for common disorders such as acute myocardial infarction, heart failure and stroke is uncertain. We examined recent national trends in mortality and rates of hospital admission for these 3 conditions. Methods We analyzed mortality data from Statistic Canada’s Canadian Mortality Database and data on hospital admissions from the Canadian Institute for Health Information’s Hospital Morbidity Database for the period 1994–2004. We determined age- and sex-standardized rates of death and hospital admissions per 100 000 population aged 20 years and over as well as in-hospital case-fatality rates. Results The overall age- and sex-standardized rate of death from cardiovascular disease in Canada declined 30.0%, from 360.6 per 100 000 in 1994 to 252.5 per 100 000 in 2004. During the same period, the rate fell 38.1% for acute myocardial infarction, 23.5% for heart failure and 28.2% for stroke, with improvements observed across most age and sex groups. The age- and sex-standardized rate of hospital admissions decreased 27.6% for stroke and 27.2% for heart failure. The rate for acute myocardial infarction fell only 9.2%. In contrast, the relative decline in the inhospital case-fatality rate was greatest for acute myocardial infarction (33.1%; p < 0.001). Much smaller relative improvements in case-fatality rates were noted for heart failure (8.1%) and stroke (8.9%). Interpretation The rates of death and hospital admissions for acute myocardial infarction, heart failure and stroke in Canada changed at different rates over the 10-year study period. Awareness of these trends may guide future efforts for health promotion and health care planning and help to determine priorities for research and treatment. PMID:19546444
Babaev, M A; Eremenko, A A; Ziuliaeva, T P; Fedulova, S V; Molochnikov, I O; Fominykh, M V; Poliakova, P V; Dzemeshkevich, S L
2014-01-01
The article deals with a retrospective study devoted to the combined methods of myocardial support in cardiosurgical patients with chronic heart failure (III-IY FC according to NYHA) and low myocardial reserves capacity (LVEF 28.3 +/- 9.4%). This methods include pharmacologic (Levosimendan) and mechanical support (IABP). During the work we have analyzed data of 116 patients and measured pressure in the pulmonary artery (mmHg), end-systolic volume (ESV ml), end-diastolic volume (ED, ml), stroke volume output (SVO, ml), left ventricular ejection fraction (LVEF, %). We evaluated the level of valvular insufficiency and pulmonary hypertension (PH) and BNP concentration (pg/ml). The following indications for the usage of pharmacological and/or mechanical myocardial support were identified: I) Preventive usage of pharmacological and/or mechanical myocardial support is recommended for patients with CHF III-IY FC (NYHA) and low left ventricular EF(< or = 35%), significant valvular insufficiency, PH, PICS (postinfarction cardiosclerosis); 2) The certain method of the support can be chosen with the help of Levosimendan infusion testing; 3) In case one of the above mentioned indications (point 1) or in case of mild reaction to levosimendan infusion in patients with the lesions of more than 2 coronary arteries (including the trunk of the left coronary artery) the usage of combined support is recommended; 4) In case of < or = 6 scores according to EUROSCORE scale, lesions of 2 or more coronary arteries, tricuspid insufficiency (TriI), PH, and high pressure in pulmonary artery (higher than the 2nd degree), high end-diastolic volume, end-systolic volume of LV the isolated usage of levosimendan is recommended; 5) In case of significant ischemic heart disease, PICS, lesions of more than 2 coronary arteries, (including the trunk of the left coronary artery) but without significant decrease of pressure in the pulmonary artery, end-diastolic volume, end-systolic volume and TriI the isolated usage of IABP is recommended.
Ohsawa, Masaki; Okamura, Tomonori; Tanno, Kozo; Ogasawara, Kuniaki; Itai, Kazuyoshi; Yonekura, Yuki; Konishi, Kazuki; Omama, Shinichi; Miyamatsu, Naomi; Turin, Tanvir Chowdhury; Morino, Yoshihiro; Itoh, Tomonori; Onoda, Toshiyuki; Sakata, Kiyomi; Ishibashi, Yasuhiro; Makita, Shinji; Nakamura, Motoyuki; Tanaka, Fumitaka; Kuribayashi, Toru; Ohta, Mutsuko; Okayama, Akira
2017-08-01
The relative and absolute risks of stroke and heart failure attributable to atrial fibrillation (AF) have not been sufficiently examined. A prospective study of 23,731 community-dwelling Japanese individuals was conducted. Participants were divided into two groups based on the presence or absence of prevalent AF (n = 338 and n = 23,393, respectively). Excess events (EE) due to AF and relative risks (RRs) determined using the non-AF group as the reference for incident stroke and heart failure were estimated using Poisson regression stratified by age groups (middle-aged: 40-69 years old; elderly: 70 years of age or older) after adjustment for sex and age. There were 611 cases of stroke and 98 cases of heart failure during the observation period (131,088 person-years). AF contributed to a higher risk of stroke both in middle-aged individuals (EE 10.4 per 1000 person-years; RR 4.88; 95% confidence interval [CI], 2.88-8.29) and elderly individuals (EE 18.3 per 1000 person-years; RR 3.05; 95% CI, 2.05-4.54). AF also contributed to a higher risk of heart failure in middle-aged individuals (EE 3.7 per 1000 person-years; RR 8.18; 95% CI, 2.41-27.8) and elderly individuals (EE 15.4 per 1000 person-years; RR 7.82; 95% CI, 4.11-14.9). Results obtained from multivariate-adjusted analysis were similar (stroke: EE 8.9 per 1000 person-years; RR 4.40; 95% CI, 2.57-7.55 in middle-aged and EE 17.4 per 1000 person-years; RR 2.97; 95% CI, 1.99-4.43 in elderly individuals; heart failure: EE 3.1 per 1000 person-years; RR 7.22; 95% CI, 2.06-25.3 in middle-aged and EE 14.1 per 1000 person-years; RR 7.41; 95% CI, 3.86-14.2 in elderly individuals). AF increased the risk of stroke by the same magnitude as that reported previously in Western countries. AF increased the RR of heart failure more than that in Western populations. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.
Kivimäki, Mika; Jokela, Markus; Nyberg, Solja T; Singh-Manoux, Archana; Fransson, Eleonor I; Alfredsson, Lars; Bjorner, Jakob B; Borritz, Marianne; Burr, Hermann; Casini, Annalisa; Clays, Els; De Bacquer, Dirk; Dragano, Nico; Erbel, Raimund; Geuskens, Goedele A; Hamer, Mark; Hooftman, Wendela E; Houtman, Irene L; Jöckel, Karl-Heinz; Kittel, France; Knutsson, Anders; Koskenvuo, Markku; Lunau, Thorsten; Madsen, Ida E H; Nielsen, Martin L; Nordin, Maria; Oksanen, Tuula; Pejtersen, Jan H; Pentti, Jaana; Rugulies, Reiner; Salo, Paula; Shipley, Martin J; Siegrist, Johannes; Steptoe, Andrew; Suominen, Sakari B; Theorell, Töres; Vahtera, Jussi; Westerholm, Peter J M; Westerlund, Hugo; O'Reilly, Dermot; Kumari, Meena; Batty, G David; Ferrie, Jane E; Virtanen, Marianna
2015-10-31
Long working hours might increase the risk of cardiovascular disease, but prospective evidence is scarce, imprecise, and mostly limited to coronary heart disease. We aimed to assess long working hours as a risk factor for incident coronary heart disease and stroke. We identified published studies through a systematic review of PubMed and Embase from inception to Aug 20, 2014. We obtained unpublished data for 20 cohort studies from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium and open-access data archives. We used cumulative random-effects meta-analysis to combine effect estimates from published and unpublished data. We included 25 studies from 24 cohorts in Europe, the USA, and Australia. The meta-analysis of coronary heart disease comprised data for 603,838 men and women who were free from coronary heart disease at baseline; the meta-analysis of stroke comprised data for 528,908 men and women who were free from stroke at baseline. Follow-up for coronary heart disease was 5·1 million person-years (mean 8·5 years), in which 4768 events were recorded, and for stroke was 3·8 million person-years (mean 7·2 years), in which 1722 events were recorded. In cumulative meta-analysis adjusted for age, sex, and socioeconomic status, compared with standard hours (35-40 h per week), working long hours (≥55 h per week) was associated with an increase in risk of incident coronary heart disease (relative risk [RR] 1·13, 95% CI 1·02-1·26; p=0·02) and incident stroke (1·33, 1·11-1·61; p=0·002). The excess risk of stroke remained unchanged in analyses that addressed reverse causation, multivariable adjustments for other risk factors, and different methods of stroke ascertainment (range of RR estimates 1·30-1·42). We recorded a dose-response association for stroke, with RR estimates of 1·10 (95% CI 0·94-1·28; p=0·24) for 41-48 working hours, 1·27 (1·03-1·56; p=0·03) for 49-54 working hours, and 1·33 (1·11-1·61; p=0·002) for 55 working hours or more per week compared with standard working hours (ptrend<0·0001). Employees who work long hours have a higher risk of stroke than those working standard hours; the association with coronary heart disease is weaker. These findings suggest that more attention should be paid to the management of vascular risk factors in individuals who work long hours. Medical Research Council, Economic and Social Research Council, European Union New and Emerging Risks in Occupational Safety and Health research programme, Finnish Work Environment Fund, Swedish Research Council for Working Life and Social Research, German Social Accident Insurance, Danish National Research Centre for the Working Environment, Academy of Finland, Ministry of Social Affairs and Employment (Netherlands), US National Institutes of Health, British Heart Foundation. Copyright © 2015 Kivimäki et al. Open Access article distributed under the terms of CC BY. Published by Elsevier Ltd.. All rights reserved.
Wilker, Elissa H; Preis, Sarah R; Beiser, Alexa S; Wolf, Philip A; Au, Rhoda; Kloog, Itai; Li, Wenyuan; Schwartz, Joel; Koutrakis, Petros; DeCarli, Charles; Seshadri, Sudha; Mittleman, Murray A
2015-05-01
Long-term exposure to ambient air pollution is associated with cerebrovascular disease and cognitive impairment, but whether it is related to structural changes in the brain is not clear. We examined the associations between residential long-term exposure to ambient air pollution and markers of brain aging using magnetic resonance imaging. Framingham Offspring Study participants who attended the seventh examination were at least 60 years old and free of dementia and stroke were included. We evaluated associations between exposures (fine particulate matter [PM2.5] and residential proximity to major roadways) and measures of total cerebral brain volume, hippocampal volume, white matter hyperintensity volume (log-transformed and extensive white matter hyperintensity volume for age), and covert brain infarcts. Models were adjusted for age, clinical covariates, indicators of socioeconomic position, and temporal trends. A 2-μg/m(3) increase in PM2.5 was associated with -0.32% (95% confidence interval, -0.59 to -0.05) smaller total cerebral brain volume and 1.46 (95% confidence interval, 1.10 to 1.94) higher odds of covert brain infarcts. Living further away from a major roadway was associated with 0.10 (95% confidence interval, 0.01 to 0.19) greater log-transformed white matter hyperintensity volume for an interquartile range difference in distance, but no clear pattern of association was observed for extensive white matter. Exposure to elevated levels of PM2.5 was associated with smaller total cerebral brain volume, a marker of age-associated brain atrophy, and with higher odds of covert brain infarcts. These findings suggest that air pollution is associated with insidious effects on structural brain aging even in dementia- and stroke-free persons. © 2015 American Heart Association, Inc.
Izzy, Saef; Rubin, Daniel B; Ahmed, Firas S; Akbik, Feras; Renault, Simone; Sylvester, Katelyn W; Vaitkevicius, Henrikas; Smallwood, Jennifer A; Givertz, Michael M; Feske, Steven K
2018-05-01
Left ventricular assist devices (LVADs) have emerged as an effective treatment for patients with advanced heart failure refractory to medical therapy. Post-LVAD strokes are an important cause of morbidity and reduced quality of life. Data on risks that distinguish between ischemic and hemorrhagic post-LVAD strokes are limited. The aim of this study was to determine the incidence of post-LVAD ischemic and hemorrhagic strokes, their association with stroke risk factors, and their effect on mortality. Data are collected prospectively on all patients with LVADs implanted at Brigham and Women's Hospital. We added retrospectively collected clinical data for these analyses. From 2007 to 2016, 183 patients (median age, 57; 80% male) underwent implantation of HeartMate II LVAD as a bridge to transplant (52%), destination therapy (39%), or bridge to transplant candidacy (8%). A total of 48 strokes occurred in 39 patients (21%): 28 acute ischemic strokes in 24 patients (13%) and 20 intracerebral hemorrhages in 19 patients (10.3%). First events occurred at a median of 238 days from implantation (interquartile range, 93-515) among those who developed post-LVAD stroke. All but 9 patients (4.9%) were on warfarin (goal international normalized ratio, 2-3.5) and all received aspirin (81-325 mg). Patients with chronic obstructive pulmonary disease were more likely to have an ischemic stroke (odds ratio, 2.96; 95% confidence interval, 1.14-7.70). Dialysis-dependent patients showed a trend toward a higher risk of hemorrhagic stroke (odds ratio, 6.31; 95% confidence interval, 0.99-40.47). Hemorrhagic stroke was associated with higher mortality (odds ratio, 3.92; 95% confidence interval, 1.34-11.45) than ischemic stroke (odds ratio, 3.17; 95% confidence interval, 1.13-8.85). Stroke is a major cause of morbidity and mortality in patients on LVAD support. Chronic obstructive pulmonary disease increases the risk of ischemic stroke, whereas dialysis may increase the risk of hemorrhagic stroke. Although any stroke increases mortality, post-LVAD hemorrhagic stroke was associated with higher mortality compared with ischemic stroke. © 2018 American Heart Association, Inc.
Numerical Cerebrospinal System Modeling in Fluid-Structure Interaction.
Garnotel, Simon; Salmon, Stéphanie; Balédent, Olivier
2018-01-01
Cerebrospinal fluid (CSF) stroke volume in the aqueduct is widely used to evaluate CSF dynamics disorders. In a healthy population, aqueduct stroke volume represents around 10% of the spinal stroke volume while intracranial subarachnoid space stroke volume represents 90%. The amplitude of the CSF oscillations through the different compartments of the cerebrospinal system is a function of the geometry and the compliances of each compartment, but we suspect that it could also be impacted be the cardiac cycle frequency. To study this CSF distribution, we have developed a numerical model of the cerebrospinal system taking into account cerebral ventricles, intracranial subarachnoid spaces, spinal canal and brain tissue in fluid-structure interactions. A numerical fluid-structure interaction model is implemented using a finite-element method library to model the cerebrospinal system and its interaction with the brain based on fluid mechanics equations and linear elasticity equations coupled in a monolithic formulation. The model geometry, simplified in a first approach, is designed in accordance with realistic volume ratios of the different compartments: a thin tube is used to mimic the high flow resistance of the aqueduct. CSF velocity and pressure and brain displacements are obtained as simulation results, and CSF flow and stroke volume are calculated from these results. Simulation results show a significant variability of aqueduct stroke volume and intracranial subarachnoid space stroke volume in the physiological range of cardiac frequencies. Fluid-structure interactions are numerous in the cerebrospinal system and difficult to understand in the rigid skull. The presented model highlights significant variations of stroke volumes under cardiac frequency variations only.
Overestimation of Susceptibility Vessel Sign: A Predictive Marker of Stroke Cause.
Zhang, Ruiting; Zhou, Ying; Liu, Chang; Zhang, Meixia; Yan, Shenqiang; Liebeskind, David S; Lou, Min
2017-07-01
The extent of blooming artifact may reflect the amount of paramagnetic material. We thus assessed the overestimation ratio of susceptibility vessel sign (SVS) on susceptibility-weighted imaging, defined as the extent of SVS width beyond the lumen and examined its value for predicting the stroke cause in acute ischemic stroke patients. We included consecutive acute ischemic stroke patients with proximal large artery occlusion who underwent both susceptibility-weighted imaging and time-of-flight magnetic resonance angiography within 8 hours poststroke onset. We calculated the length, width, and overestimation ratio of SVS on susceptibility-weighted imaging and then investigated their values for predicting the stroke cause, respectively. One-hundred eleven consecutive patients (72 female; mean age, 66.6±13.4 years) were enrolled, among whom 39 (35.1%) were diagnosed with cardiogenic embolism, 43 (38.7%) with large artery atherosclerosis, and 29 (26.1%) with undetermined cause. The presence, length, width, and overestimation ratio of SVS were all independently associated with the cause of cardiogenic embolism after adjusting for baseline National Institute of Health Stroke Scale and infarct volume. After excluded patients with undetermined cause, the sensitivity and specificity of overestimation ratio of SVS for cardiogenic embolism were 0.971 and 0.913; for the length of SVS, they were 0.629 and 0.739; for the width of SVS, they were 0.829 and 0.826, respectively. The overestimation ratio of SVS can predict cardiogenic embolism, with both high sensitivity and specificity, which can be helpful for the management of acute ischemic stroke patients in hyperacute stage. © 2017 American Heart Association, Inc.
Data and Statistics: Heart Failure
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Bavo, A M; Pouch, A M; Degroote, J; Vierendeels, J; Gorman, J H; Gorman, R C; Segers, P
2017-01-04
As the intracardiac flow field is affected by changes in shape and motility of the heart, intraventricular flow features can provide diagnostic indications. Ventricular flow patterns differ depending on the cardiac condition and the exploration of different clinical cases can provide insights into how flow fields alter in different pathologies. In this study, we applied a patient-specific computational fluid dynamics model of the left ventricle and mitral valve, with prescribed moving boundaries based on transesophageal ultrasound images for three cardiac pathologies, to verify the abnormal flow patterns in impaired hearts. One case (P1) had normal ejection fraction but low stroke volume and cardiac output, P2 showed low stroke volume and reduced ejection fraction, P3 had a dilated ventricle and reduced ejection fraction. The shape of the ventricle and mitral valve, together with the pathology influence the flow field in the left ventricle, leading to distinct flow features. Of particular interest is the pattern of the vortex formation and evolution, influenced by the valvular orifice and the ventricular shape. The base-to-apex pressure difference of maximum 2mmHg is consistent with reported data. We used a CFD model with prescribed boundary motion to describe the intraventricular flow field in three patients with impaired diastolic function. The calculated intraventricular flow dynamics are consistent with the diagnostic patient records and highlight the differences between the different cases. The integration of clinical images and computational techniques, therefore, allows for a deeper investigation intraventricular hemodynamics in patho-physiology. Copyright © 2016 Elsevier Ltd. All rights reserved.
Pollonini, L; Padhye, N S; Re, R; Torricelli, A; Simpson, R J; Dacso, C C
2015-05-01
Heart rate (HR) is a valuable and widespread measure for physical training programs, although its description of conditioning is limited to the cardiac response to exercise. More comprehensive measures of exercise adaptation include cardiac output (Q̇), stroke volume (SV) and oxygen uptake (V̇O2), but these physiological parameters can be measured only with cumbersome equipment installed in clinical settings. In this work, we explore the ability of pulse transit time (PTT) to represent a valuable pairing with HR for indirectly estimating Q̇, SV and V̇O2 non-invasively. PTT was measured as the time interval between the peak of the electrocardiographic (ECG) R-wave and the onset of the photoplethysmography (PPG) waveform at the periphery (i.e. fingertip) with a portable sensor. Fifteen healthy young subjects underwent a graded incremental cycling protocol after which HR and PTT were correlated with Q̇, SV and V̇O2 using linear mixed models. The addition of PTT significantly improved the modeling of Q̇, SV and V̇O2 at the individual level ([Formula: see text] for SV, 0.548 for Q̇, and 0.771 for V̇O2) compared to predictive models based solely on HR ([Formula: see text] for SV, 0.503 for Q̇, and 0.745 for V̇O2). While challenges in sensitivity and artifact rejection exist, combining PTT with HR holds potential for development of novel wearable sensors that provide exercise assessment largely superior to HR monitors.
Bursting into space: alterations of sympathetic control by space travel
NASA Technical Reports Server (NTRS)
Eckberg, D. L.
2003-01-01
AIM: Astronauts return to Earth with reduced red cell masses and hypovolaemia. Not surprisingly, when they stand, their heart rates may speed inordinately, their blood pressures may fall, and some may experience frank syncope. We studied autonomic function in six male astronauts (average +/- SEM age: 40 +/- 2 years) before, during, and after the 16-day Neurolab space shuttle mission. METHOD: We recorded electrocardiograms, finger photoplethysmographic arterial pressures, respiration, peroneal nerve muscle sympathetic activity, plasma noradrenaline and noradrenaline kinetics, and cardiac output, and we calculated stroke volume and total peripheral resistance. We perturbed autonomic function before and during spaceflight with graded Valsalva manoeuvres and lower body suction, and before and after the mission with passive upright tilt. RESULTS: In-flight baseline sympathetic nerve activity was increased above pre-flight levels (by 10-33%) in three subjects, in whom noradrenaline spillover and clearance also were increased. Valsalva straining provoked greater reductions of arterial pressure, and proportionally greater sympathetic responses in space than on Earth. Lower body suction elicited greater increases of sympathetic nerve activity, plasma noradrenaline, and noradrenaline spillover in space than on Earth. After the Neurolab mission, left ventricular stroke volume was lower and heart rate was higher during tilt, than before spaceflight. No astronaut experienced orthostatic hypotension or pre-syncope during 10 min of post-flight tilting. CONCLUSION: We conclude that baseline sympathetic outflow, however measured, is higher in space than on earth, and that augmented sympathetic nerve responses to Valsalva straining, lower body suction, and post-flight upright tilt represent normal adjustments to greater haemodynamic stresses associated with hypovolaemia.
Sexual intercourse and risk of ischaemic stroke and coronary heart disease: the Caerphilly study
Ebrahim, S; May, M; Ben, S; McCarron, P; Frankel, S; Yarnell, J; Davey, S
2002-01-01
Objective: To examine the relation between frequency of sexual intercourse and risk of ischaemic stroke and coronary heart disease. Design: Cohort study with 20 year follow up. Setting: The town of Caerphilly, South Wales and five adjacent villages. Subjects: 914 men aged 45–59 years at time of recruitment in 1979 to 1983. Main outcome measures: Ischaemic stroke and coronary heart disease, all first events and fatal events. Results: Of the 914 men studied, 197 (21.5%) reported sexual intercourse less often than once a month, 231 (25.3%) reported sexual intercourse twice or more a week, and the remaining 486 (53.2%) men fell into the intermediate category. Frequency of sexual intercourse was not associated with all first ischaemic stroke events: age adjusted odds ratios (95% CI) for intermediate and low frequency of sexual intercourse of 0.61 (0.32 to 1.16) and 0.71 (0.34 to 1.49) respectively compared with the reference category of high frequency. A graded relation with fatal coronary heart disease events was observed in events recorded up to 10 years. The age adjusted relative risk (95% CI) of fatal coronary heart disease contrasting low frequency of sexual intercourse (that is, less than monthly) with the highest group (at least twice a week) was 2.80 (1.13 to 6.96, test for trend, p=0.04) which was not attenuated by adjustment for a wide range of potential confounders. Longer follow up to 20 years showed attenuation of this risk with odds of 1.69 (95% CI 0.90 to 3.20), contrasting low frequency of sexual intercourse with the highest group. Conclusions: The differential relation between frequency of sexual intercourse, stroke and coronary heart disease suggests that confounding is an unlikely explanation for the observed association with fatal coronary heart disease events. Middle aged men should be heartened to know that frequent sexual intercourse is not likely to result in a substantial increase in risk of strokes, and that some protection from fatal coronary events may be an added bonus. PMID:11812807
Thompson, B Gregory; Brown, Robert D; Amin-Hanjani, Sepideh; Broderick, Joseph P; Cockroft, Kevin M; Connolly, E Sander; Duckwiler, Gary R; Harris, Catherine C; Howard, Virginia J; Johnston, S Claiborne Clay; Meyers, Philip M; Molyneux, Andrew; Ogilvy, Christopher S; Ringer, Andrew J; Torner, James
2015-08-01
The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms. Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee. Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment. © 2015 American Heart Association, Inc.
Lackland, Daniel T; Roccella, Edward J; Deutsch, Anne F; Fornage, Myriam; George, Mary G; Howard, George; Kissela, Brett M; Kittner, Steven J; Lichtman, Judith H; Lisabeth, Lynda D; Schwamm, Lee H; Smith, Eric E; Towfighi, Amytis
2014-01-01
Stroke mortality has been declining since the early 20th century. The reasons for this are not completely understood, although the decline is welcome. As a result of recent striking and more accelerated decreases in stroke mortality, stroke has fallen from the third to the fourth leading cause of death in the United States. This has prompted a detailed assessment of the factors associated with the change in stroke risk and mortality. This statement considers the evidence for factors that have contributed to the decline and how they can be used in the design of future interventions for this major public health burden. Writing group members were nominated by the committee chair and co-chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiological studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize evidence and to indicate gaps in current knowledge. All members of the writing group had the opportunity to comment on this document and approved the final version. The document underwent extensive American Heart Association internal peer review, Stroke Council leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee. The decline in stroke mortality over the past decades represents a major improvement in population health and is observed for both sexes and for all racial/ethnic and age groups. In addition to the overall impact on fewer lives lost to stroke, the major decline in stroke mortality seen among people <65 years of age represents a reduction in years of potential life lost. The decline in mortality results from reduced incidence of stroke and lower case-fatality rates. These significant improvements in stroke outcomes are concurrent with cardiovascular risk factor control interventions. Although it is difficult to calculate specific attributable risk estimates, efforts in hypertension control initiated in the 1970s appear to have had the most substantial influence on the accelerated decline in stroke mortality. Although implemented later, diabetes mellitus and dyslipidemia control and smoking cessation programs, particularly in combination with treatment of hypertension, also appear to have contributed to the decline in stroke mortality. The potential effects of telemedicine and stroke systems of care appear to be strong but have not been in place long enough to indicate their influence on the decline. Other factors had probable effects, but additional studies are needed to determine their contributions. The decline in stroke mortality is real and represents a major public health and clinical medicine success story. The repositioning of stroke from third to fourth leading cause of death is the result of true mortality decline and not an increase in mortality from chronic lung disease, which is now the third leading cause of death in the United States. There is strong evidence that the decline can be attributed to a combination of interventions and programs based on scientific findings and implemented with the purpose of reducing stroke risks, the most likely being improved control of hypertension. Thus, research studies and the application of their findings in developing intervention programs have improved the health of the population. The continued application of aggressive evidence-based public health programs and clinical interventions is expected to result in further declines in stroke mortality.
Elevated troponin in patients with acute stroke - Is it a true heart attack?
Dous, George V; Grigos, Angela C; Grodman, Richard
2017-09-01
Although the prognostic value of a positive troponin in an acute stroke patient is still uncertain, it is a commonly encountered clinical situation given that Ischemic Heart Disease (IHD) and cerebrovascular disease (CVD) frequently co-exist in the same patient and share similar risk factors. Our objectives in this review are to (1) identify the biologic relationship between acute cerebrovascular stroke and elevated troponin levels, (2) determine the pathophysiologic differences between positive troponin in the setting of acute stroke versus acute myocardial infarction (AMI), and (3) examine whether positive troponin in the setting of acute stroke has prognostic significance. We also will provide an insight analysis of some of the available studies and will provide guidance for a management approach based on the available data according to the current guidelines.
What Are the Warning Signs of Stroke?
ANSWERS by heart Cardiovascular Conditions What Are the Warning Signs of Stroke? Brain tissue affected by blockage ... risk factors. • Reduce your risk factors. • Learn the warning signs of stroke. • Know what to do if ...
Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease.
Höllmer, M; Willesen, J L; Tolver, A; Koch, J
2017-02-01
Myxomatous mitral valve disease (MMVD) induces progressive left atrial (LA) enlargement. The LA modulates left ventricular filling and performance through its reservoir, conduit, and contractile function. Assessment of LA size and function may provide valuable information on the level of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. This prospective study included 205 client-owned dogs of different breeds, 114 healthy dogs, and 91 dogs with MMVD of different disease severities. Using two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function. Left atrial volume and LA stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume <2.25mL/kg was the optimal cut off identified for excluding congestive heart failure in dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100%. An active LA emptying fraction <24% and/or a LA expansion index <126% were suggestive of congestive heart failure in dogs with chronic MMVD with a sensitivity of 77% and a specificity of 89% and a sensitivity of 82% and a specificity of 82%, respectively. Dogs with MMVD appear to have larger LA volumes with poorer LA function. Deteriorating LA function, characterized by a decreasing reservoir and active contractile function, was evident in dogs with MMVD with increasing disease severity. Copyright © 2016 Elsevier B.V. All rights reserved.
Dodecafluoropentane Emulsion Decreases Infarct Volume in a Rabbit Ischemic Stroke Model
Culp, William C.; Woods, Sean D.; Skinner, Robert D.; Brown, Aliza T.; Lowery, John D.; Johnson, Jennifer L. H.; Unger, Evan C.; Hennings, Leah J.; Borrelli, Michael J.; Roberson, Paula K.
2011-01-01
Purpose To assess the efficacy of dodecafluoropentane emulsion (DDFPe), a nano droplet emulsion with significant oxygen transport potential, in decreasing infarct volume using an insoluble emboli rabbit stroke model. Methods New Zealand White rabbits (n=64; 5.1±0.50 kg) received angiography and embolic spheres in the internal carotid artery occluding branches. Rabbits were randomly assigned to groups in 4-hour and 7-hour studies. Four-hour groups included: control (n=7, embolized without treatment) or DDFPe treatment 30-min before stroke (n=7), or at stroke onset (n=8), 30-min after stroke (n=5), 1-hour after stroke (n=7), 2-hours after stroke (n=5), or 3-hours after stroke (n=6). Seven-hour groups included control (n=6), DDFPe at 1-hour after stroke (n=8), and DDFPe at 6-hours after stroke (n=5). DDFPe dose was 2% w/v (weight/volume) intravenous injection, 0.6 mL/kg, and repeated every 90 minutes as time allowed. Following euthanasia infarct volume was determined using vital stains on brain sections. Results At 4-hours, median percent infarct volume decreased for all DDFPe treatment times (pre-treatment=0.30%, p=0.004; onset=0.20%, p=0.004; 30-min=0.35%, p=0.009, 1-hour=0.30%, p=0.01, 2-hours=0.40%, p=0.009, 3-hours=0.25%, p=0.003) compared with controls (3.20%). At 7-hours, median percent infarct volume decreased with treatment at 1-hour (0.25%, p=0.007) but not for 6-hours (1.4%, p=0.49) compared with controls (2.2%). Conclusions Intravenous DDFPe in an animal model decreases infarct volumes and protects brain tissue from ischemia justifying further investigation. PMID:22079515
Legendre, Antoine; Bonnet, D; Bosquet, L
2018-01-01
Global ventricular response to exercise may be useful in follow-up of patients with residual right outflow tract lesions after congenital heart disease repair. In this context, impedance cardiography is considered accurate for stroke volume (SV) measurement during exercise testing, however, to date, only partial assessment of its reliability has been reported. We retrospectively evaluated relative and absolute reliability of peak SV by impedance cardiography during exercise using intraclass correlation (ICC) and standard error of measurement (SEM) in this population. Peak SV was measured in 30 young patients (mean age 14.4 years ± 2.1) with right ventricular outflow tract reconstruction who underwent two cardiopulmonary exercise tests at a mean one-year interval. SV was measured using a signal morphology impedance cardiography analysis device (PhysioFlow ® ) and was indexed to body surface area. ICC of peak indexed SV measurement was 0.80 and SEM was 10.5%. High heterogeneity was seen when comparing patients according to peak indexed SV; in patients with peak SV < 50 ml/m 2 (15 patients), ICC rose to 0.95 and SEM dropped to 2.7%, while in patients with a peak SV > 50 ml/m 2 relative and absolute reliability decreased (ICC = 0.45, SEM = 12.2%). Peak exercise SV assessment by a PhysioFlow ® device represents a highly reliable method in patients with residual right outflow tract lesions after congenital heart disease repair, especially in patients with peak SV < 50 ml/m 2 . In this latter group, a peak SV decrease > 7.3% (corresponding to the minimum "true" difference) should be considered a clinically-relevant decrease in global ventricular performance and taken into account when deciding whether to perform residual lesion removal.
Mortola, Jacopo P; Wills, Kathryn; Trippenbach, Teresa; Al Awam, Khalid
2010-03-01
In the chick embryo at day 3, gas exchange occurs by diffusion and oxygen consumption (V(O(2))) does not depend on the cardiovascular convection of O(2). Whether or not this is the case in hypoxia is not known and represents the aim of the study. The heart of chicken embryos at 72 h (stage HH18) was filmed through a window of the eggshell by a camera attached to a microscope. Stroke volume was estimated from the changes in heart silhouette between systole and diastole. V(O(2))was measured by a closed system methodology. In normoxia, a decrease in temperature (T) from 39 to 31 degrees C had parallel depressant effects on V(O(2))and HR. At 39 degrees C, a progressive decrease in O(2) lowered V(O(2)); HR was maintained until the O(2) threshold of approximately 15%. In severe hypoxia (4% O(2)) V(O(2))and HR were, respectively, approximately 12% and approximately 62% of normoxia. At 32 degrees C the hypoxic threshold for HR was significantly lower. During constant hypoxia (7% O(2)) V(O(2))did not respond to T, while the HR response was preserved. Stroke volume changed little with changes in T or O(2), except at 6 and 4% O(2), when it decreased by approximately 20 and 30%. In embryos growth-retarded because of incubation in chronic hypoxia, V(O(2))and HR responses to T and hypoxia were similar to those of normal embryos. We conclude that in the early embryo during hypoxia cardiovascular O(2) convection is not responsible for the drop in V(O(2)). The generalised hypometabolic response, in combination with the extremely small cardiac V(O(2)), probably explains the minor effects of hypoxia on cardiac activity. Copyright 2009 Elsevier Inc. All rights reserved.
Heerdt, P M; Pond, C G; Kussman, M K; Triantafillou, A N
1993-01-01
Despite numerous technologic advances in intraoperative monitoring, the only methods routinely available for assessment of right ventricular function in lung transplant recipients are continuous measurement of right heart pressures and intermittent thermodilution determination of cardiac output and ejection fraction. Additional data may now be obtained with transesophageal echocardiography, although this technology is expensive and not widely available and requires diverting attention from a potentially unstable patient for data acquisition and analysis. Recently, a Doppler pulmonary artery catheter was introduced that measures beat-to-beat pulmonary artery blood flow-velocity, cross sectional area, and volume flow. Because of data indicating that acceleration of blood in the pulmonary artery (measured as the first derivative of either the velocity or flow waveform) is a sensitive indicator of right ventricular contractility, we have used waveforms obtained with the catheter for assessment of right ventricular pump function (stroke volume and peak pulmonary artery flow rate) and contractility in heart surgery patients. We report here our experience with this method in two patients undergoing left single lung transplantation.
Heart Attack or Sudden Cardiac Arrest: How Are They Different?
... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Heart Attack or Sudden Cardiac Arrest: How Are They Different? ... and procedures related to heart disease and stroke. Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ...
EPA Healthy Heart Program Webinar
EPA is raising awareness of heart disease and its link to air pollution and other environmental factors as a partner in the Million Hearts, a national initiative to prevent 1 million heart attacks and strokes by 2017.
EPA Science Matters: February 13, 2018
February is American Heart Month. EPA is raising awareness of heart disease and its link to air pollution and other environmental factors as a partner in Million Hearts, a national initiative to prevent heart attacks and strokes.
Cardiac Resynchronization Therapy (CRT)
... with other treatments to achieve the best results. Heart Failure Questions to Ask Your Doctor Use these questions ... and procedures related to heart disease and stroke. Heart Failure • Home • About Heart Failure • Causes and Risks for ...
Braun, Lynne T; Grady, Kathleen L; Kutner, Jean S; Adler, Eric; Berlinger, Nancy; Boss, Renee; Butler, Javed; Enguidanos, Susan; Friebert, Sarah; Gardner, Timothy J; Higgins, Phil; Holloway, Robert; Konig, Madeleine; Meier, Diane; Morrissey, Mary Beth; Quest, Tammie E; Wiegand, Debra L; Coombs-Lee, Barbara; Fitchett, George; Gupta, Charu; Roach, William H
2016-09-13
The mission of the American Heart Association/American Stroke Association includes increasing access to high-quality, evidence-based care that improves patient outcomes such as health-related quality of life and is consistent with the patients' values, preferences, and goals. Awareness of and access to palliative care interventions align with the American Heart Association/American Stroke Association mission. The purposes of this policy statement are to provide background on the importance of palliative care as it pertains to patients with advanced cardiovascular disease and stroke and their families and to make recommendations for policy decisions. Palliative care, defined as patient- and family-centered care that optimizes health-related quality of life by anticipating, preventing, and treating suffering, should be integrated into the care of all patients with advanced cardiovascular disease and stroke early in the disease trajectory. Palliative care focuses on communication, shared decision making about treatment options, advance care planning, and attention to physical, emotional, spiritual, and psychological distress with inclusion of the patient's family and care system. Our policy recommendations address the following: reimbursement for comprehensive delivery of palliative care services for patients with advanced cardiovascular disease and stroke; strong payer-provider relationships that involve data sharing to identify patients in need of palliative care, identification of better care and payment models, and establishment of quality standards and outcome measurements; healthcare system policies for the provision of comprehensive palliative care services during hospitalization, including goals of care, treatment decisions, needs of family caregivers, and transition to other care settings; and health professional education in palliative care as part of licensure requirements. © 2016 American Heart Association, Inc.
Moghari, Mehdi H; Barthur, Ashita; Amaral, Maria E; Geva, Tal; Powell, Andrew J
2018-07-01
To develop and validate a new prospective respiratory motion compensation algorithm for free-breathing whole-heart 3D cine steady-state free precession (SSFP) imaging. In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re-purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end-expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction. Prospective validation was carried out in patients (N = 17) by comparing in each a conventional breath-hold 2D cine ventricular short-axis stack and a free-breathing whole-heart 3D cine data set. All 3D cine SSFP acquisitions were successful and the mean scan time was 5.9 ± 2.7 min. Left and right ventricular end-diastolic, end-systolic, and stroke volumes by 3D cine SSFP were all larger than those from 2D cine SSFP. This bias was < 6% except for right ventricular end-systolic volume that was 12%. The 3D cine images had a lower ventricular blood-to-myocardium contrast ratio, contrast-to-noise ratio, mass, and subjective quality score. The novel prospective respiratory motion compensation method for 3D cine SSFP imaging was robust and efficient and yielded slightly larger ventricular volumes and lower mass compared to breath-hold 2D cine imaging. Magn Reson Med 80:181-189, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.
An Economic Evaluation Comparing Stroke Telemedicine to Conventional Stroke Medicine
ERIC Educational Resources Information Center
Budhram, Stanley Chandra
2011-01-01
Stroke is not only a serious medical problem, but it also poses an enormous economic burden on society. Stroke ranks the third as the leading cause of death in the United States behind heart disease and cancer. The survivors of stroke suffer from various degrees of long-term disability which create a severe financial burden on society. University…
Hinkle, Janice L; Becker, Kyra J; Kim, Jong S; Choi-Kwon, Smi; Saban, Karen L; McNair, Norma; Mead, Gillian E
2017-07-01
At least half of all stroke survivors experience fatigue; thus, it is a common cause of concern for patients, caregivers, and clinicians after stroke. This scientific statement provides an international perspective on the emerging evidence surrounding the incidence, prevalence, quality of life, and complex pathogenesis of poststroke fatigue. Evidence for pharmacological and nonpharmacological interventions for management are reviewed, as well as the effects of poststroke fatigue on both stroke survivors and caregivers. © 2017 American Heart Association, Inc.
Lu, Mingming; Peng, Peng; Cui, Yuanyuan; Qiao, Huiyu; Li, Dongye; Cai, Jianming; Zhao, Xihai
2018-03-01
This study aimed to investigate the association between carotid plaque progression and subsequent recurrent events using magnetic resonance imaging. Sixty-three symptomatic patients with ipsilateral carotid atherosclerotic stenosis (30%-69% stenosis) determined by ultrasound underwent first and second carotid artery magnetic resonance imaging for carotid artery at baseline and ≥6 months after the first scan, respectively. All the patients had clinical follow-up after the second magnetic resonance scan for ≤5 years until the onset of recurrent transient ischemic attack or stroke. Presence/absence of carotid plaque compositional features, particularly intraplaque hemorrhage and fibrous cap rupture was identified. The annual progression of carotid wall volume between 2 magnetic resonance scans was measured. Univariate and multivariate Cox regression was used to calculate the hazard ratio and corresponding 95% confidence interval of carotid plaque features in discriminating recurrent events. Receiver-operating-characteristic-curve analysis was conducted to determine the area-under-the-curve of carotid plaque features in predicting recurrent events. Sixty-three patients (mean age: 66.5±10.0 years old; 54 males) were eligible for final statistics analysis. During a mean follow-up duration of 55.1±13.6 months, 14.3% of patients (n=9) experienced ipsilateral recurrent transient ischemic attack/stroke. The annual progression of carotid wall volume was significantly associated with recurrent events before (hazard ratio, 1.14 per 10 mm 3 ; 95% confidence interval, 1.02-1.27; P =0.019) and after (hazard ratio, 1.19 per 10 mm3; 95% confidence interval, 1.03-1.37; P =0.022) adjusted for confounding factors. In discriminating the recurrence of transient ischemia attack/stroke, receiver-operator curve analysis indicated that combined with annual progression of wall volume, there was a significant incremental improvement in the area-under-the-curve of intraplaque hemorrhage (area-under-the-curve: 0.69-0.81) and fibrous cap rupture (area-under-the-curve: 0.73-0.84). The annual progression of carotid wall volume is independently associated with recurrent ischemic cerebrovascular events, and this measurement has added value for intraplaque hemorrhage and fibrous cap rupture in predicting future events. © 2018 American Heart Association, Inc.
Myocardial function during bradycardia events in preterm infants.
de Waal, Koert; Phad, Nilkant; Collins, Nick; Boyle, Andrew
2016-07-01
Transient bradycardia episodes are common in preterm infants and often secondary to apnea. Decreased ventilation with resultant hypoxemia is believed to be the predominant mechanism. Sudden bradycardias without apnea are also reported, possibly due to vagal stimulation. Point of care ultrasound is used to diagnose and follow cardiovascular complications in preterm infants. Inadvertently, the operator would sometimes capture bradycardia events. This study reports on left ventricular function during such events. We retrospectively reviewed our cardiac ultrasound database for bradycardia events. Apical four or three chamber images before, during and after a bradycardia event were analysed with speckle tracking software which provides systolic and diastolic parameters of myocardial motion, deformation and volume. Over a 2year period, 15 bradycardia events were noted in 14 patients with a median gestational age of 26weeks (range 23 to 29). Heart rate decreased by an average of 43% (171/min to 98/min). Myocardial velocity and longitudinal strain rate during the atrial component of diastole were reduced during bradycardia. Longitudinal strain during systole was increased and radial deformation was unchanged. Ventricular volumes and ejection fraction did not change. Most parameters returned to baseline values after the event. Longitudinal systolic strain rate remained lower and stroke volume was 12% higher compared to baseline. Parameters of systolic contractility and stroke volume were maintained and parameters of atrial contractility were reduced during mild to moderate bradycardia in preterm infants. Bradycardia reduces total cardiac output with a compensatory increase detected following the event. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Elstad, Maja; Walløe, Lars; Holme, Nathalie L A; Maes, Elke; Thoresen, Marianne
2015-03-01
Arterial blood pressure variations are an independent risk factor for end organ failure. Respiratory sinus arrhythmia (RSA) is a sign of a healthy cardiovascular system. However, whether RSA counteracts arterial blood pressure variations during the respiratory cycle remains controversial. We restricted normal RSA with non-invasive intermittent positive pressure ventilation (IPPV) to test the hypothesis that RSA normally functions to stabilize mean arterial blood pressure. Ten young volunteers were investigated during metronome-paced breathing and IPPV. Heart rate (ECG), mean arterial blood pressure and left stroke volume (finger arterial pressure curve) and right stroke volume (pulsed ultrasound Doppler) were recorded, while systemic and pulmonary blood flow were calculated beat-by-beat. Respiratory variations (high-frequency power, 0.15-0.40 Hz) in cardiovascular variables were estimated by spectral analysis. Phase angles and correlation were calculated by cross-spectral analysis. The magnitude of RSA was reduced from 4.9 bpm(2) (95% CI 3.0, 6.2) during metronome breathing to 2.8 bpm(2) (95% CI 1.1, 5.0) during IPPV (p = 0.03). Variations in mean arterial blood pressure were greater (2.3 mmHg(2) (95% CI 1.4, 3.9) during IPPV than during metronome breathing (1.0 mmHg(2) [95% CI 0.7, 1.3]) (p = 0.014). Respiratory variations in right and left stroke volumes were inversely related in the respiratory cycle during both metronome breathing and IPPV. RSA magnitude is lower and mean arterial blood pressure variability is greater during IPPV than during metronome breathing. We conclude that in healthy humans, RSA stabilizes mean arterial blood pressure at respiratory frequency.
Nonlinear lymphangion pressure-volume relationship minimizes edema
Venugopal, Arun M.; Stewart, Randolph H.; Laine, Glen A.
2010-01-01
Lymphangions, the segments of lymphatic vessel between two valves, contract cyclically and actively pump, analogous to cardiac ventricles. Besides having a discernable systole and diastole, lymphangions have a relatively linear end-systolic pressure-volume relationship (with slope Emax) and a nonlinear end-diastolic pressure-volume relationship (with slope Emin). To counter increased microvascular filtration (causing increased lymphatic inlet pressure), lymphangions must respond to modest increases in transmural pressure by increasing pumping. To counter venous hypertension (causing increased lymphatic inlet and outlet pressures), lymphangions must respond to potentially large increases in transmural pressure by maintaining lymph flow. We therefore hypothesized that the nonlinear lymphangion pressure-volume relationship allows transition from a transmural pressure-dependent stroke volume to a transmural pressure-independent stroke volume as transmural pressure increases. To test this hypothesis, we applied a mathematical model based on the time-varying elastance concept typically applied to ventricles (the ratio of pressure to volume cycles periodically from a minimum, Emin, to a maximum, Emax). This model predicted that lymphangions increase stroke volume and stroke work with transmural pressure if Emin < Emax at low transmural pressures, but maintain stroke volume and stroke work if Emin= Emax at higher transmural pressures. Furthermore, at higher transmural pressures, stroke work is evenly distributed among a chain of lymphangions. Model predictions were tested by comparison to previously reported data. Model predictions were consistent with reported lymphangion properties and pressure-flow relationships of entire lymphatic systems. The nonlinear lymphangion pressure-volume relationship therefore minimizes edema resulting from both increased microvascular filtration and venous hypertension. PMID:20601461
A patient-specific CFD-based study of embolic particle transport for stroke
NASA Astrophysics Data System (ADS)
Mukherjee, Debanjan; Shadden, Shawn C.
2014-11-01
Roughly 1/3 of all strokes are caused by an embolus traveling to a cerebral artery and blocking blood flow in the brain. A detailed understanding of the dynamics of embolic particles within arteries is the basis for this study. Blood flow velocities and emboli trajectories are resolved using a coupled Euler-Lagrange approach. Computer model of the major arteries is extracted from patient image data. Blood is modeled as a Newtonian fluid, discretized using the Finite Volume method, with physiologically appropriate inflow and outflow boundary conditions. The embolus trajectory is modeled using Lagrangian particle equations accounting for embolus interaction with blood as well as vessel wall. Both one and two way fluid-particle coupling are considered, the latter being implemented using momentum sources augmented to the discretized flow equations. The study determines individual embolus path up to arteries supplying the brain, and compares the size-dependent distribution of emboli amongst vessels superior to the aortic-arch, and the role of fully coupled blood-embolus interactions in modifying both trajectory and distribution when compared with one-way coupling. Specifically for intermediate particle sizes the model developed will better characterize the risks for embolic stroke. American Heart Association (AHA) Grant: Embolic Stroke: Anatomic and Physiologic Insights from Image-Based CFD.
Borst, Jordi; Berkhemer, Olvert A; Roos, Yvo B W E M; van Bavel, Ed; van Zwam, Wim H; van Oostenbrugge, Robert J; van Walderveen, Marianne A A; Lingsma, Hester F; van der Lugt, Aad; Dippel, Diederik W J; Yoo, Albert J; Marquering, Henk A; Majoie, Charles B L M
2015-12-01
The utility of computed tomographic perfusion (CTP)-based patient selection for intra-arterial treatment of acute ischemic stroke has not been proven in randomized trials and requires further study in a cohort that was not selected based on CTP. Our objective was to study the relationship between CTP-derived parameters and outcome and treatment effect in patients with acute ischemic stroke because of a proximal intracranial arterial occlusion. We included 175 patients who underwent CTP in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN). Association of CTP-derived parameters (ischemic-core volume, penumbra volume, and percentage ischemic core) with outcome was estimated with multivariable ordinal logistic regression as an adjusted odds ratio for a shift in the direction of a better outcome on the modified Rankin Scale. Interaction between CTP-derived parameters and treatment effect was determined using multivariable ordinal logistic regression. Interaction with treatment effect was also tested for mismatch (core <70 mL; penumbra core >1.2; penumbra core >10 mL). The adjusted odds ratio for improved functional outcome for ischemic core, percentage ischemic core, and penumbra were 0.79 per 10 mL (95% confidence interval: 0.71-0.89; P<0.001), 0.82 per 10% (95% confidence interval: 0.66-0.90; P=0.002), and 0.97 per 10 mL (96% confidence interval: 0.92-1.01; P=0.15), respectively. No significant interaction between any of the CTP-derived parameters and treatment effect was observed. We observed no significant interaction between mismatch and treatment effect. CTP seems useful for predicting functional outcome, but cannot reliably identify patients who will not benefit from intra-arterial therapy. © 2015 American Heart Association, Inc.
Adib-Samii, Poneh; Devan, William; Traylor, Matthew; Lanfranconi, Silvia; Zhang, Cathy R; Cloonan, Lisa; Falcone, Guido J; Radmanesh, Farid; Fitzpatrick, Kaitlin; Kanakis, Allison; Rothwell, Peter M; Sudlow, Cathie; Boncoraglio, Giorgio B; Meschia, James F; Levi, Chris; Dichgans, Martin; Bevan, Steve; Rosand, Jonathan; Rost, Natalia S; Markus, Hugh S
2015-02-01
Epidemiological studies suggest that white matter hyperintensities (WMH) are extremely heritable, but the underlying genetic variants are largely unknown. Pathophysiological heterogeneity is known to reduce the power of genome-wide association studies (GWAS). Hypertensive and nonhypertensive individuals with WMH might have different underlying pathologies. We used GWAS data to calculate the variance in WMH volume (WMHV) explained by common single nucleotide polymorphisms (SNPs) as a measure of heritability (SNP heritability [HSNP]) and tested the hypothesis that WMH heritability differs between hypertensive and nonhypertensive individuals. WMHV was measured on MRI in the stroke-free cerebral hemisphere of 2336 ischemic stroke cases with GWAS data. After adjustment for age and intracranial volume, we determined which cardiovascular risk factors were independent predictors of WMHV. Using the genome-wide complex trait analysis tool to estimate HSNP for WMHV overall and within subgroups stratified by risk factors found to be significant in multivariate analyses. A significant proportion of the variance of WMHV was attributable to common SNPs after adjustment for significant risk factors (HSNP=0.23; P=0.0026). HSNP estimates were higher among hypertensive individuals (HSNP=0.45; P=7.99×10(-5)); this increase was greater than expected by chance (P=0.012). In contrast, estimates were lower, and nonsignificant, in nonhypertensive individuals (HSNP=0.13; P=0.13). A quarter of variance is attributable to common SNPs, but this estimate was greater in hypertensive individuals. These findings suggest that the genetic architecture of WMH in ischemic stroke differs between hypertensives and nonhypertensives. Future WMHV GWAS studies may gain power by accounting for this interaction. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wolters Kluwer.
Chu, Hannah X; Broughton, Brad R S; Kim, Hyun Ah; Lee, Seyoung; Drummond, Grant R; Sobey, Christopher G
2015-07-01
Ly6C(hi) monocytes are generally thought to exert a proinflammatory role in acute tissue injury, although their impact after injuries to the central nervous system is poorly defined. CC chemokine receptor 2 is expressed on Ly6C(hi) monocytes and plays an essential role in their extravasation and transmigration into the brain after cerebral ischemia. We used a selective CC chemokine receptor 2 antagonist, INCB3344, to assess the effect of Ly6C(hi) monocytes recruited into the brain early after ischemic stroke. Male C57Bl/6J mice underwent occlusion of the middle cerebral artery for 1 hour followed by 23 hours of reperfusion. Mice were administered either vehicle (dimethyl sulfoxide/carboxymethylcellulose) or INCB3344 (10, 30 or 100 mg/kg IP) 1 hour before ischemia and at 2 and 6 hours after ischemia. At 24 hours, we assessed functional outcomes, infarct volume, and quantified the immune cells in blood and brain by flow cytometry or immunofluorescence. Gene expression of selected inflammatory markers was assessed by quantitative polymerase chain reaction. Ly6C(hi) monocytes were increased 3-fold in the blood and 10-fold in the brain after stroke, and these increases were selectively prevented by INCB3344 in a dose-dependent manner. Mice treated with INCB3344 exhibited markedly worse functional outcomes and larger infarct volumes, in association with reduced M2 polarization and increased peroxynitrite production in macrophages, compared with vehicle-treated mice. Our data suggest that Ly6C(hi) monocytes exert an acute protective effect after ischemic stroke to limit brain injury and functional deficit that involves promotion of M2 macrophage polarization. © 2015 American Heart Association, Inc.
[Cardiovascular effects of prostaglandin F 2 alpha in early pregnancy].
Retzke, U; Schwarz, R
1976-01-01
In 10 normotensive healthy early pregnant women cardiovascular studies were done before, during and after the intravenous administration of prostaglandin F2alpha with the method of quantitative sphygmometry. Arterial blood pressure was measured graphically with an automatic sphygmomanometer unit. Velocity of aortic pulse wave was determined directly on the principle of exact electronic timing. Prostaglandin F2alpha was infused with electric pump in the dosage of 6, 5, 13 and 26 mug per minute for 30 minutes in each case. Arterial blood pressure is nearly constant. Heart rate, the elasticity coefficient of the arteries E' and total peripheral resistance decreases significantly. Stroke volume, cardiac output, work and power of the heart increases significantly. Nevertheless there are no contra-indications on the part of cardiovascular system for using prostaglandin F2alpha for induction of abortion
Peng, Jian-Ping; Zheng, Hang
2017-08-01
We aimed to quantitatively assess the potential relationship between kidney stones and coronary heart disease or stroke. A meta-analysis was conducted on eligibly studies published before 31 May 2016 in PubMed or Embase. The data were pooled, and the relationship was assessed by the random-effect model with inverse variance-weighted procedure. The results were expressed as relative risk (RR) with 95% confidence intervals (95%CI). Eight studies of 11 cohorts (n = 11) were included in our analysis with 3,658,360 participants and 157,037 cases. We found that a history of kidney stones was associated with increased risk of coronary heart disease (CHD) (RR = 1.24; 95%CI: 1.14-1.36; I = 79.0%, n = 11); similar effect on myocardial infarction, a serious condition of CHD, was observed (RR = 1.24; 95%CI: 1.10-1.40; I = 80.4%, n = 8). We also found that a history of kidney stones may increase the risk of stroke (RR = 1.21, 95%CI: 1.06-1.38; I = 54.7%, n = 4). In subgroup analysis, the risk of coronary heart disease was higher in men (RR = 1.23, 95%CI: 1.02-1.49) while the risk for stroke was higher in women (RR = 1.12; 95%CI: 1.03-1.21). No obvious publications bias was detected (Egger test: P = .47). Kidney stones are associated with increased risk of coronary heart disease and stroke, and the effect may differ by sex.
A semi-automatic method for left ventricle volume estimate: an in vivo validation study
NASA Technical Reports Server (NTRS)
Corsi, C.; Lamberti, C.; Sarti, A.; Saracino, G.; Shiota, T.; Thomas, J. D.
2001-01-01
This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.
Increased risks of coronary heart disease and stroke among spousal caregivers of cancer patients.
Ji, Jianguang; Zöller, Bengt; Sundquist, Kristina; Sundquist, Jan
2012-04-10
Spousal caregivers of cancer patients suffer psychological and physical burdens that may affect their risk of subsequently developing coronary heart disease and stroke. Cancer patients were identified in the Swedish Cancer Registry, and information on their spouses was retrieved from the Swedish Multi-Generation Register. Follow-up of caregivers was performed from the date of the first diagnosis of cancer in their spouses through 2008. Standardized incidence ratios were calculated for spousal caregivers of cancer patients compared with those without an affected spouse. After the cancer diagnosis in wives, the risks of coronary heart disease, ischemic stroke, and hemorrhagic stroke in husbands were 1.13 (95% confidence interval [CI], 1.10-1.16), 1.24 (95% CI, 1.21-1.27), and 1.25 (95% CI, 1.18-1.32), respectively. The corresponding risks in wives with an affected husband were 1.13 (95% CI, 1.10-1.16), 1.29 (95% CI, 1.26-1.32), and 1.27 (95% CI, 1.19-1.34). The increases were consistent over time and were more pronounced if the spouse was affected by a cancer with a high mortality rate, such as pancreatic and lung cancers. Spousal caregivers of cancer patients have increased risks of coronary heart disease and stroke that persist over time. Clinical attention should be paid to spousal caregivers, especially those caring for cancer patients with high mortality rates.
... of the American Heart Association Cardiology Patient Page Aspirin Jeremy S. Paikin , John W. Eikelboom Download PDF https:// ... treatment of heart attack and stroke. How Does Aspirin Work? Aspirin reduces the risk of heart attacks ...
ERIC Educational Resources Information Center
Wells, M. B.; Turner, S.; Martin, D. M.; Roy, A.
1997-01-01
A study of 120 British adults with intellectual disability found they had higher risk factors of developing coronary heart disease and stroke than the general population. There was a greater incidence of obesity and considerably lower physical activity levels than the general population. Several also had abnormal cholesterol readings. (CR)
ERIC Educational Resources Information Center
Yessis, Jennifer; Riley, Barbara; Stockton, Lisa; Brodovsky, Sharon; Von Sychowski, Shirley
2013-01-01
The Heart and Stroke Foundation's Spark Together for Healthy Kids™ (Spark) is a multiyear initiative in Ontario, Canada, that takes a population approach to obesity prevention. It focuses on creating healthy environments by improving access to healthy foods and physical activity, with an emphasis on strengthening the advocacy capacity of…
Obesity and heart failure as a mediator of the cerebrorenal interaction.
Jindal, Ankur; Whaley-Connell, Adam; Sowers, James R
2013-01-01
The obesity epidemic is contributing substantially to the burden of cardiovascular disease including heart disease and congestive heart failure, in the United States and the rest of the world. Overnutrition as a driver of obesity, promotes alterations in fatty acid, lipid, and glucose metabolism that influence myocardial function and progression of heart failure from diastolic to systolic failure. The association of progressive heart failure and progressive chronic kidney disease is well documented and often referred to as the cardiorenal syndrome, as well as a prognosticator for cerebrovascular disease (e.g. stroke). Whether the relationship between obesity, heart disease/failure and risk for chronic kidney disease and stroke is direct or a confluence of risk factors is poorly understood. Copyright © 2013 S. Karger AG, Basel.
Importance of the splanchnic vascular bed in human blood pressure regulation.
NASA Technical Reports Server (NTRS)
Rowell, L. B.; Detry, J.-M. R.; Blackmon, J. R.; Wyss, C.
1972-01-01
Three-part experiment in which five subjects were exposed to lower body negative pressure (LBNP) at -50 mm Hg below the iliac crests. Duration of LBNP to earliest vagal symptoms was 7 to 21 min; all data are expressed as changes from control period to the last measurements before these symptoms. In part I, forearm blood flow (by Whitney gauge) fell 45% during LBNP. In part II, splanchnic blood flow (from arterial clearance hepatic extraction of indocyanine green) fell 32% and splanchnic vascular resistance rose 30%. In part III, cardiac output fell 28%, stroke volume 51%, and central blood volume 21%. Total peripheral resistance and heart rate rose 19% and 52%. Of the reduction in total vascular conductance, decreased splanchnic conductance accounted for approximately 33%; skin plus muscle conductance decreased similarly.
[Myocardial contractility and hemodynamics in hypothyroidism].
Selivonenko, V G
1977-01-01
The author determined the phasic structure of the systole of the left ventricle by the method of polycardiography and hemodynamics in 20 patients suffering from hypothyrodism. Blood plasma and erythrocyte electrolytes were examined at the same time. Patients with hypothyroidism displayed a phasic syndrome of hypodynamia and a marked correlation between the phase of the synchronous contraction, the period of ejection, the strength of contraction of the left ventricle and the electrolyte content. Sodium and magnesium produced the greatest influence on the phasic structure of the systole; potassium and calcium had a lesser effect. The heart stroke volume diminished; as to the cardiac index, expenditure of the energy of cardiac contractions directed to the maintenance of movement of 1 litre of the minute blood volume; the external work, and the peripheral vascular resistance displayed no significant change.
High Blood Pressure, Afib and Your Risk of Stroke
... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More High Blood Pressure, AFib and Your Risk of Stroke Updated:Aug ... have a stroke for the first time have high blood pressure . And an irregular atrial heart rhythm — a condition ...
Pullicino, Patrick; Thompson, John L P; Barton, Bruce; Levin, Bruce; Graham, Susan; Freudenberger, Ronald S
2006-02-01
Warfarin is widely prescribed for patients with heart failure without level 1 evidence, and an adequately powered randomized study is needed. The Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction study is a National Institutes of Health-funded, randomized, double-blind clinical trial with a target enrollment of 2860 patients. It is designed to test with 90% power the 2-sided primary null hypothesis of no difference between warfarin (International Normalized Ratio 2.5-3) and aspirin (325 mg) in 3- to 5-year event-free survival for the composite endpoint of death, or stroke (ischemic or hemorrhagic) among patients with cardiac ejection fraction < or =35% who do not have atrial fibrillation or mechanical prosthetic heart valves. Secondary analyses will compare warfarin and aspirin for reduction of all-cause mortality, ischemic stroke, and myocardial infarction (MI), balanced against the risk of intracerebral hemorrhage, among women and African Americans; and compare warfarin and aspirin for prevention of stroke alone. Randomization is stratified by site, New York Heart Association (NYHA) heart class (I vs II-IV), and stroke or transient ischemic attack (TIA) within 1 year before randomization versus no stroke or TIA in that period. NYHA class I patients will not exceed 20%, and the study has a target of 20% (or more) patients with stroke or TIA within 12 months. Randomized patients receive active warfarin plus placebo or active aspirin plus placebo, double-blind. The results should help guide the selection of optimum antithrombotic therapy for patients with left ventricular dysfunction.
Howard, George; Cushman, Mary; Prineas, Ronald J.; Howard, Virginia J.; Moy, Claudia S.; Sullivan, Lisa M.; D’Agostino, Ralph B.; McClure, Leslie A.; Pulley, Lea Vonne; Safford, Monika M.
2009-01-01
Purpose Geographic variation in risk factors may underlie geographic disparities in coronary heart disease (CHD) and stroke mortality. Methods Framingham CHD Risk Score (FCRS) and Stroke Risk Score (FSRS) were calculated for 25,770 stroke-free and 22,247 CHD-free participants from the REasons for Geographic And Racial Differences in Stroke cohort. Vital statistics provided age-adjusted CHD and stroke mortality rates. In an ecologic analysis, the age-adjusted, race-sex weighted, average state-level risk factor levels were compared to state-level mortality rates. Results There was no relationship between CHD and stroke mortality rates (r = 0.04; p = 0.78), but there was between CHD and stroke risk scores at the individual (r = 0.68; p < 0.0001) and state (r = 0.64, p < 0.0001) level. There was a stronger (p < 0.0001) association between state-level FCRS and state-level CHD mortality (r = 0.28, p = 0.18), than between FSRS and stroke mortality (r = 0.12, p = 0.56). Conclusions Weak associations between CHD and stroke mortality and strong associations between CHD and stroke risk scores suggest geographic variation in risk factors may not underlie geographic variations in stroke and CHD mortality. The relationship between risk factor scores and mortality was stronger for CHD than stroke. PMID:19285103
... is also used to reduce the risk of heart attack and stroke in patients at risk for these ... survival in patients with heart failure after a heart attack. Ramipril is in a class of medications called ...
Alter, P; Rupp, H; Rominger, M B; Klose, K J; Maisch, B
2008-01-01
In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.
NASA Technical Reports Server (NTRS)
Convertino, Victor A.
2002-01-01
The development of orthostatic hypotension and instability immediately after return from spaceflight has been a significant operational problem to astronauts for more than four decades. Significant reductions in stroke volume and peripheral vascular resistance contribute to ineffective maintenance of systemic arterial blood pressure during standing after spaceflight despite compensatory elevations in heart rate. The primary mechanism underlying reduced stroke volume appears to be a reduction in preload associated with reduced circulating blood volume, although cardiac atrophy might also contribute. Space flight and ground based experiments have demonstrated that an inability to provide adequate peripheral vasoconstriction in astronauts that become presyncopal may be associated with several mechanisms including reduced sympathetic nerve activity, arterial smooth muscle atrophy and/or hyporeactivity, hypersensitivity of beta-adrenergic receptors, etc. In addition, an inability to provide adequate tachycardia in presyncopal subjects may be associated with reduced carotid-cardiac baroreflex sensitivity. Based on the current knowledge and understanding of cardiovascular mechanisms that are altered during exposure to microgravity, a major focus of future research should be directed to the systematic evaluation of potential countermeasures that specifically target and restore the function of these mechanisms. Based on a preliminary systematic evaluation presented in this review, acute physical exercise designed to elicit maximal effort, G-suit inflation, artificial gravity, and specific pharmacological interventions, alone or in combination, have shown promise as successful countermeasures that provide protection against post-flight orthostatic intolerance.
Convertino, Victor A
2002-12-01
The development of orthostatic hypotension and instability immediately after return from spaceflight has been a significant operational problem to astronauts for more than four decades. Significant reductions in stroke volume and peripheral vascular resistance contribute to ineffective maintenance of systemic arterial blood pressure during standing after spaceflight despite compensatory elevations in heart rate. The primary mechanism underlying reduced stroke volume appears to be a reduction in preload associated with reduced circulating blood volume, although cardiac atrophy might also contribute. Space flight and ground based experiments have demonstrated that an inability to provide adequate peripheral vasoconstriction in astronauts that become presyncopal may be associated with several mechanisms including reduced sympathetic nerve activity, arterial smooth muscle atrophy and/or hyporeactivity, hypersensitivity of beta-adrenergic receptors, etc. In addition, an inability to provide adequate tachycardia in presyncopal subjects may be associated with reduced carotid-cardiac baroreflex sensitivity. Based on the current knowledge and understanding of cardiovascular mechanisms that are altered during exposure to microgravity, a major focus of future research should be directed to the systematic evaluation of potential countermeasures that specifically target and restore the function of these mechanisms. Based on a preliminary systematic evaluation presented in this review, acute physical exercise designed to elicit maximal effort, G-suit inflation, artificial gravity, and specific pharmacological interventions, alone or in combination, have shown promise as successful countermeasures that provide protection against post-flight orthostatic intolerance.
Swift, Andrew J; Capener, Dave; Hammerton, Charlotte; Thomas, Steven M; Elliot, Charlie; Condliffe, Robin; Wild, Jim M; Kiely, David G
2015-01-01
Sex differences exist in both the prevalence and survival of patients with idiopathic pulmonary arterial hypertension (IPAH). Men are less frequently affected by the condition but have worse outcome as compared to females. We sought to characterise the sex related differences in right ventricular remodelling in age matched male and female patients with IPAH using cardiac magnetic resonance imaging (MRI). A case controlled pair-matched study was conducted with patients matched by age and sex. Steady state free precession (SSFP) MRI of the heart was performed at 1.5T. Cardiac volume, function and mass measurements were corrected for age, sex and BSA according to reference data. 40 age and sex matched patients with IPAH were identified. The mean age was 57 (SD 17) in both male and female cohorts. Men had proportionally lower right ventricular (RV) ejection fraction, RV stroke volume and LV stroke volume than females, p=0.028, p=0.007 and p=0.013, respectively. However, there was no significant difference in RV mass or haemodynamic indices of mPAP and PVR between males and females. Male patients with IPAH have proportionally worse RV function despite similar afterload. We hypothesise that adaptive remodelling of the RV in response to increased afterload in IPAH is more effective in females.
Swift, Andrew J.; Capener, Dave; Hammerton, Charlotte; Thomas, Steven M.; Elliot, Charlie; Condliffe, Robin; Wild, Jim M.; Kiely, David G.
2015-01-01
Purpose Sex differences exist in both the prevalence and survival of patients with idiopathic pulmonary arterial hypertension (IPAH). Men are less frequently affected by the condition but have worse outcome as compared to females. We sought to characterise the sex related differences in right ventricular remodelling in age matched male and female patients with IPAH using cardiac magnetic resonance imaging (MRI). Methods A case controlled pair-matched study was conducted with patients matched by age and sex. Steady state free precession (SSFP) MRI of the heart was performed at 1.5T. Cardiac volume, function and mass measurements were corrected for age, sex and BSA according to reference data. Results 40 age and sex matched patients with IPAH were identified. The mean age was 57 (SD 17) in both male and female cohorts. Men had proportionally lower right ventricular (RV) ejection fraction, RV stroke volume and LV stroke volume than females, p=0.028, p=0.007 and p=0.013, respectively. However, there was no significant difference in RV mass or haemodynamic indices of mPAP and PVR between males and females. Conclusion Male patients with IPAH have proportionally worse RV function despite similar afterload. We hypothesise that adaptive remodelling of the RV in response to increased afterload in IPAH is more effective in females. PMID:25996939
... Director of Heart Failure, and Director of Cardiac MRI, Providence VA Medical Center and the Cardiovascular Institute ... stroke . Diagnosis Imaging with echocardiography, CT, and/or MRI Primary heart tumors are difficult to diagnose because ...
2010-01-01
Introduction We developed a minimally invasive, closed chest pig model with the main aim to describe hemodynamic function during surface cooling, steady state severe hypothermia (one hour at 25°C) and surface rewarming. Methods Twelve anesthetized juvenile pigs were acutely catheterized for measurement of left ventricular (LV) pressure-volume loops (conductance catheter), cardiac output (Swan-Ganz), and for vena cava inferior occlusion. Eight animals were surface cooled to 25°C, while four animals were kept as normothermic time-matched controls. Results During progressive cooling and steady state severe hypothermia (25°C) cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), maximal deceleration of pressure in the cardiac cycle (dP/dtmin), indexes of LV contractility (preload recruitable stroke work, PRSW, and maximal acceleration of pressure in the cardiac cycle, dP/dtmax) and LV end diastolic and systolic volumes (EDV and ESV) were significantly reduced. Systemic vascular resistance (SVR), isovolumetric relaxation time (Tau), and oxygen content in arterial and mixed venous blood increased significantly. LV end diastolic pressure (EDP) remained constant. After rewarming all the above mentioned hemodynamic variables that were depressed during 25°C remained reduced, except for CO that returned to pre-hypothermic values due to an increase in heart rate. Likewise, SVR and EDP were significantly reduced after rewarming, while Tau, EDV, ESV and blood oxygen content normalized. Serum levels of cardiac troponin T (TnT) and tumor necrosis factor-alpha (TNF-α) were significantly increased. Conclusions Progressive cooling to 25°C followed by rewarming resulted in a reduced systolic, but not diastolic left ventricular function. The post-hypothermic increase in heart rate and the reduced systemic vascular resistance are interpreted as adaptive measures by the organism to compensate for a hypothermia-induced mild left ventricular cardiac failure. A post-hypothermic increase in TnT indicates that hypothermia/rewarming may cause degradation of cardiac tissue. There were no signs of inadequate global oxygenation throughout the experiments. PMID:21092272
Dehydration, hemodynamics and fluid volume optimization after induction of general anesthesia.
Li, Yuhong; He, Rui; Ying, Xiaojiang; Hahn, Robert G
2014-01-01
Fluid volume optimization guided by stroke volume measurements reduces complications of colorectal and high-risk surgeries. We studied whether dehydration or a strong hemodynamic response to general anesthesia increases the probability of fluid responsiveness before surgery begins. Cardiac output, stroke volume, central venous pressure and arterial pressures were measured in 111 patients before general anesthesia (baseline), after induction and stepwise after three bolus infusions of 3 ml/kg of 6% hydroxyethyl starch 130/0.4 (n=86) or Ringer's lactate (n=25). A subgroup of 30 patients who received starch were preloaded with 500 ml of Ringer's lactate. Blood volume changes were estimated from the hemoglobin concentration and dehydration was estimated from evidence of renal water conservation in urine samples. Induction of anesthesia decreased the stroke volume to 62% of baseline (mean); administration of fluids restored this value to 84% (starch) and 68% (Ringer's). The optimized stroke volume index was clustered around 35-40 ml/m2/beat. Additional fluid boluses increased the stroke volume by ≥10% (a sign of fluid responsiveness) in patients with dehydration, as suggested by a low cardiac index and central venous pressure at baseline and by high urinary osmolality, creatinine concentration and specific gravity. Preloading and the hemodynamic response to induction did not correlate with fluid responsiveness. The blood volume expanded 2.3 (starch) and 1.8 (Ringer's) times over the infused volume. Fluid volume optimization did not induce a hyperkinetic state but ameliorated the decrease in stroke volume caused by anesthesia. Dehydration, but not the hemodynamic response to the induction, was correlated with fluid responsiveness.
Yang, Xiaomeng; Li, Zixiao; Zhao, Xingquan; Wang, Chunjuan; Liu, Liping; Wang, Chunxue; Pan, Yuesong; Li, Hao; Wang, David; Hart, Robert G; Wang, Yilong; Wang, Yongjun
2016-02-01
Guidelines recommend oral anticoagulation for ischemic stroke patients with atrial fibrillation, and previous studies have shown the underuse of anticoagulation for these patients in China. We sought to explore the underlying reasons and factors that currently affect the use of warfarin in China. From June 2012 to January 2013, 19 604 patients with acute ischemic stroke were admitted to 219 urban hospitals voluntarily participating in the China National Stroke Registry II. Multivariable logistic regression models using the generalized estimating equation method were used to identify patient/hospital factors independently associated with warfarin use at discharge. Among the 952 acute ischemic stroke patients with nonvalvular atrial fibrillation, 19.4% were discharged on warfarin. The risk of bleeding (52.8%) and patient refusal (31.9%) were the main reasons for not prescribing anticoagulation. Larger/teaching hospitals were more likely to prescribe warfarin. Older patients, heavy drinkers, patients with higher National Institutes of Health Stroke Scale score on admission were less likely to be given warfarin, whereas patients with history of heart failure and an international normalized ratio between 2.0 and 3.0 during hospitalization were significantly associated with warfarin use at discharge. The rate of warfarin use remains low among patients with ischemic stroke and known nonvalvular atrial fibrillation in China. Hospital size and academic status together with patient age, heart failure, heavy alcohol drinking, international normalized ratio in hospital, and stroke severity on admission were each independently associated with the use of warfarin at discharge. There is much room for improvement for secondary stroke prevention in nonvalvular atrial fibrillation patients in China. © 2015 American Heart Association, Inc.
Lee, Dong-Wook; Hong, Yun-Chul; Min, Kyoung-Bok; Kim, Tae-Shik; Kim, Min-Seok; Kang, Mo-Yeol
2016-01-01
Recently, the emergence of long working hours and the associated conditions such as coronary heart disease (CHD) and stroke have gained attention. The aim of this study was to investigate the association between long working hours and the 10-year-risk of CHD and stroke, estimated by Jee's health risk-appraisal model for ischemic heart disease. We analyzed data from Koreans who randomly enrolled in Korean National Health and Nutrition Examination Survey 2008-2012 and finally included 13,799 participants. The participants were classified as per their working hours: 0-30 h/week, 31-39 h/week, 40 h/week, 41-50 h/week, 51-60 h/week, 61-70 h/week, 71-80 h/week, and >80 h/week. The risks for CHD and stroke were determined using Jee's health risk-appraisal model. Multiple logistic regression was used to analyze the association between working hours and 10-year risk for CHD. The 10-year risks for CHD and stroke were significantly and positively associated with working hours in both men and women. Furthermore, higher risks for CHD and stroke were associated with longer working hours in women. Long working hours are significantly associated with the risks of CHD and stroke, estimated by Jee's health risk-appraisal model. This study suggests the need for proper management of working hours to reduce CHD risk and stroke risk in the Korean population.
Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke
Xing, Shihui; Lacey, Elizabeth H.; Skipper-Kallal, Laura M.; Jiang, Xiong; Harris-Love, Michelle L.; Zeng, Jinsheng
2016-01-01
The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor’s lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion–symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter volumes in these clusters related to verbal working memory capacity, but not other cognitive functions. Further, grey matter volumes in these areas were greater in stroke survivors than healthy control subjects. To confirm this result, 10 chronic left hemisphere stroke survivors with no history of aphasia were identified. Grey matter volumes in right temporoparietal clusters were greater in stroke survivors with aphasia compared to those without history of aphasia. These findings suggest that the grey matter structure of right hemisphere posterior dorsal stream language homologues independently contributes to language production abilities in chronic left hemisphere stroke, and that these areas may undergo hypertrophy after a stroke causing aphasia. PMID:26521078
Chen, Dongdong; Lee, Jinhwan; Gu, Xiaohuan; Wei, Ling
2015-01-01
Apelin is a peptide originally isolated from bovine stomach tissue extracts and identified as an endogenous ligand of the APJ receptor; recent work showed that apelin ameliorates the ischemic injury in the heart and the brain. Being an analogue to the angiotensin II receptor, the apelin/APJ signaling may mediate angiogenesis process. We explored the noninvasive intranasal brain delivery method and investigated therapeutic effects of apelin-13 in a focal ischemic stroke model of mice. Intranasal administration of apelin-13 (4 mg/kg) was given 30 min after the onset of stroke and repeated once daily. Three days after stroke, mice received apelin-13 had significantly reduced infarct volume and less neuronal death in the penumbra. Western blot analyses showed upregulated levels of apelin, apelin receptor APLNR, and Bcl-2 and decreased caspase-3 activation in the apelin-13-treated brain. The proinflammatory cytokines tumor necrosis factor-alpha, interleukin-1β, and chemokine monocyte chemoattractant protein-1 mRNA increased in the ischemic brain, which were significantly attenuated by apelin-13. Apelin-13 remarkably reduced microglia recruitment and activation in the penumbra according to morphological features of Iba-1-positive cells 3 days after ischemia. Apelin-13 significantly increased the expression of angiogenic factor vascular endothelial growth factor and matrix metalloproteinase-9 14 days after stroke. Angiogenesis illustrated by collagen IV + /5-bromo-2′-deoxyuridin + colabeled cells was significantly increased by the apelin-13 treatment 21 days after stroke. Finally, apelin-13 promoted the local cerebral blood flow restoration and long-term functional recovery. This study demonstrates a noninvasive intranasal delivery of apelin-13 after stroke, suggesting that the reduced inflammatory activities, decreased cell death, and increased angiogenesis contribute to the therapeutic benefits of apelin-13. PMID:26391329
American Heart Association's Call to Action for Payment and Delivery System Reform.
Bufalino, Vincent J; Berkowitz, Scott A; Gardner, Timothy J; Piña, Ileana L; Konig, Madeleine
2017-08-15
The healthcare system is undergoing a transition from paying for volume to paying for value. Clinicians, as well as public and private payers, are beginning to implement alternative delivery and payment models, such as the patient-centered medical home, accountable care organizations, and bundled payment arrangements. Implementation of these new models will necessitate delivery system transformation and will actively involve all fields of medical care, in particular medicine and surgery. This call to action, on behalf of the American Heart Association's Expert Panel on Payment and Delivery System Reform, serves to offer support and direction for further involvement by the American Heart Association. In doing so, it (1) provides baseline review and definition of the present models and some of the early results of these delivery models, including outcomes; (2) initiates a conversation within the American Heart Association on the impact of payment and delivery system reform, as well as how the American Heart Association should engage in the interest of patients; (3) issues a call to action to our organization and to cardiovascular and stroke health professionals across the country to become educated about these models so to as to understand their impact on patient care; and (4) asks the government and other funding agencies, including the American Heart Association, to begin supporting and prioritizing meaningful research endeavors to further evaluate these models. © 2017 American Heart Association, Inc.
Guan, Ling; Collet, Jean-Paul; Mazowita, Garey; Claydon, Victoria E
2018-01-01
Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye's fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or "stressors," respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke.
Guan, Ling; Collet, Jean-Paul; Mazowita, Garey; Claydon, Victoria E.
2018-01-01
Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye’s fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or “stressors,” respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke. PMID:29556209
Batty, G David; Shipley, Martin; Smith, George Davey; Kivimaki, Mika
2015-09-01
While cohort studies have revealed a range of risk factors for coronary heart disease and stroke, the extent to which the strength of these associations varies according to duration of follow-up in studies with extended disease surveillance is unclear. This was the aim of the present study. Initiated in 1967/70, the original Whitehall study is an on-going cohort study of 15,402 male UK government workers free of coronary heart disease when they took part in a baseline medical examination during which a range of standard risk factors was measured. In analyses in which we stratified by duration of follow-up, there was evidence of time-dependency for most risk factor-disease relationships. Thus, the associations of systolic and diastolic blood pressure, total cholesterol and cigarette smoking with coronary heart disease and stroke diminished in strength with increasing duration of follow-up, whereas the magnitude of the body mass index-coronary heart disease relation was unchanged. For example, the age-adjusted hazard ratios (95% confidence interval) for cigarette smoking (versus never smoked) in relation to coronary heart disease were: 2.49 (1.80, 3.44), 1.65 (1.34, 2.03), 1.36 (1.15, 1.61) and 1.32 (1.10, 1.58) for follow-up periods 0-10, 10-20, 20-30 and 30+ years, respectively. Despite a general diminution in the strength of effect over time, even in the fourth decade of follow-up, classic risk factors retained some predictive capacity for coronary heart disease and, to a lesser degree, stroke. © The European Society of Cardiology 2014.
Whincup, Peter H; Gilg, Julie A; Emberson, Jonathan R; Jarvis, Martin J; Feyerabend, Colin; Bryant, Andrew; Walker, Mary; Cook, Derek G
2004-01-01
Objective To examine the associations between a biomarker of overall passive exposure to tobacco smoke (serum cotinine concentration) and risk of coronary heart disease and stroke. Design Prospective population based study in general practice (the British regional heart study). Participants 4729 men in 18 towns who provided baseline blood samples (for cotinine assay) and a detailed smoking history in 1978-80. Main outcome measure Major coronary heart disease and stroke events (fatal and non-fatal) during 20 years of follow up. Results 2105 men who said they did not smoke and who had cotinine concentrations < 14.1 ng/ml were divided into four equal sized groups on the basis of cotinine concentrations. Relative hazards (95% confidence intervals) for coronary heart disease in the second (0.8-1.4 ng/ml), third (1.5-2.7 ng/ml), and fourth (2.8-14.0 ng/ml) quarters of cotinine concentration compared with the first (≥ 0.7 ng/ml) were 1.45 (1.01 to 2.08), 1.49 (1.03 to 2.14), and 1.57 (1.08 to 2.28), respectively, after adjustment for established risk factors for coronary heart disease. Hazard ratios (for cotinine 0.8-14.0 ν ≥ 0.7 ng/ml) were particularly increased during the first (3.73, 1.32 to 10.58) and second five year follow up periods (1.95, 1.09 to 3.48) compared with later periods. There was no consistent association between cotinine concentration and risk of stroke. Conclusion Studies based on reports of smoking in a partner alone seem to underestimate the risks of exposure to passive smoking. Further prospective studies relating biomarkers of passive smoking to risk of coronary heart disease are needed. PMID:15229131
The real estate factor: quantifying the impact of infarct location on stroke severity.
Menezes, Nina M; Ay, Hakan; Wang Zhu, Ming; Lopez, Chloe J; Singhal, Aneesh B; Karonen, Jari O; Aronen, Hannu J; Liu, Yawu; Nuutinen, Juho; Koroshetz, Walter J; Sorensen, A Gregory
2007-01-01
The severity of the neurological deficit after ischemic stroke is moderately correlated with infarct volume. In the current study, we sought to quantify the impact of location on neurological deficit severity and to delineate this impact from that of volume. We developed atlases consisting of location-weighted values indicating the relative importance in terms of neurological deficit severity for every voxel of the brain. These atlases were applied to 80 first-ever ischemic stroke patients to produce estimates of clinical deficit severity. Each patient had an MRI and National Institutes of Health Stroke Scale (NIHSS) examination just before or soon after hospital discharge. The correlation between the location-based deficit predictions and measured neurological deficit (NIHSS) scores were compared with the correlation obtained using volume alone to predict the neurological deficit. Volume-based estimates of neurological deficit severity were only moderately correlated with measured NIHSS scores (r=0.62). The combination of volume and location resulted in a significantly better correlation with clinical deficit severity (r=0.79, P=0.032). The atlas methodology is a feasible way of integrating infarct size and location to predict stroke severity. It can estimate stroke severity better than volume alone.
Bonaiuti, Donatella; Sioli, Paolo; Fumagalli, Lorenzo; Beghi, Ettore; Agostoni, Elio
2011-08-01
Acute medical complications often prevent patients with stroke from being transferred from stroke units to rehabilitation units, prolonging the occupation of hospital beds and delaying the start of intensive rehabilitation. This study defined incidence, timing, duration and risk factors of these complications during the acute phase of stroke. A retrospective case note review was made of hospital admissions of patients with stroke not associated with other disabling conditions, admitted to a stroke unit over 12 months and requiring rehabilitation for gait impairment. In this cohort, a search was made of hypertension, oxygen de-saturation, fever, and cardiac and pulmonary symptoms requiring medical intervention. Included were 135 patients. Hypertension was the most common complication (16.3%), followed by heart disease (14.8%), oxygen de-saturation (7.4%), fever (6.7%) and pulmonary disease (5.2%). Heart disease was the earliest and shortest complication. Most complications occurred during the first week. Except for hypertension, all complications resolved within 2 weeks.
NASA Technical Reports Server (NTRS)
Iwasaki, K. I.; Zhang, R.; Zuckerman, J. H.; Pawelczyk, J. A.; Levine, B. D.; Blomqvist, C. G. (Principal Investigator)
2000-01-01
Adaptation to head-down-tilt bed rest leads to an apparent abnormality of baroreflex regulation of cardiac period. We hypothesized that this "deconditioning response" could primarily be a result of hypovolemia, rather than a unique adaptation of the autonomic nervous system to bed rest. To test this hypothesis, nine healthy subjects underwent 2 wk of -6 degrees head-down bed rest. One year later, five of these same subjects underwent acute hypovolemia with furosemide to produce the same reductions in plasma volume observed after bed rest. We took advantage of power spectral and transfer function analysis to examine the dynamic relationship between blood pressure (BP) and R-R interval. We found that 1) there were no significant differences between these two interventions with respect to changes in numerous cardiovascular indices, including cardiac filling pressures, arterial pressure, cardiac output, or stroke volume; 2) normalized high-frequency (0.15-0.25 Hz) power of R-R interval variability decreased significantly after both conditions, consistent with similar degrees of vagal withdrawal; 3) transfer function gain (BP to R-R interval), used as an index of arterial-cardiac baroreflex sensitivity, decreased significantly to a similar extent after both conditions in the high-frequency range; the gain also decreased similarly when expressed as BP to heart rate x stroke volume, which provides an index of the ability of the baroreflex to alter BP by modifying systemic flow; and 4) however, the low-frequency (0.05-0.15 Hz) power of systolic BP variability decreased after bed rest (-22%) compared with an increase (+155%) after acute hypovolemia, suggesting a differential response for the regulation of vascular resistance (interaction, P < 0.05). The similarity of changes in the reflex control of the circulation under both conditions is consistent with the hypothesis that reductions in plasma volume may be largely responsible for the observed changes in cardiac baroreflex control after bed rest. However, changes in vasomotor function associated with these two conditions may be different and may suggest a cardiovascular remodeling after bed rest.
Gong, Jie; Chen, Xinguang; Li, Sijian
2015-01-01
To evaluate the efficacy of the program Keep Moving toward Healthy Heart and Healthy Brain (KM2H2) in encouraging physical activities for the prevention of heart attack and stroke among hypertensive patients enrolled in the Community-Based Hypertension Control Program (CBHCP). Cluster randomized controlled trial with three waves of longitudinal assessments at baseline, 3 and 6 months post intervention. Community-based and patient-centered self-care for behavioral intervention in urban settings of China. A total of 450 participants diagnosed with hypertension from 12 community health centers in Wuhan, China were recruited, and were randomly assigned by center to receive either KM2H2 plus standard CBHCP care (6 centers and 232 patients) or the standard care only (6 centers and 218 patients). KM2H2 is a behavioral intervention guided by the Transtheoretical Model, the Model of Personalized Medicine and Social Capital Theory. It consists of six intervention sessions and two booster sessions engineered in a progressive manner. The purpose is to motivate and maintain physical activities for the prevention of heart attack and stroke. Heart attack and stroke (clinically diagnosed, primary outcome), blood pressure (measured, secondary outcome), and physical activity (self-report, tertiary outcome) were assessed at the individual level during the baseline, 3- and 6-month post-intervention. Relative to the standard care, receiving KM2H2 was associated with significant reductions in the incidence of heart attack (3.60% vs. 7.03%, p < .05) and stroke (5.11% vs. 9.90%, p<0.05), and moderate reduction in blood pressure (-3.72 mmHg in DBP and -2.92 mmHg in DBP) at 6-month post-intervention; and significant increases in physical activity at 3- (d = 0.53, 95% CI: 0.21, 0.85) and 6-month (d = 0.45, 95% CI: 0.04, 0.85) post-intervention, respectively. The program KM2H2 is efficacious to reduce the risk of heart attack and stroke among senior patients who are on anti-hypertensive medication. Findings of this study provide solid data supporting a formal phase-III trial to establish the effectiveness of KM2H2 for use in community settings for prevention. ISRCTN Register ISRCTN12608966.
Yan, Zhaoli; Zhang, Xinyue; Li, Chunlin; Jiao, Shouchun; Dong, Wenyao
2017-05-01
Background The relationships between dietary intake of soy foods and risk of cardiovascular disease are uncertain. The aims of this study were to evaluate and summarize the evidence on the association between consumption of soy and risk of cardiovascular disease (including stroke and coronary heart disease). Methods We systematically searched the MEDLINE and EMBASE databases from their inception up to 22 February 2016. We included only observational studies, and used random-effects models to calculate summary relative risks (SRRs) and 95% confidence intervals (CIs). Results A total of 10 prospective cohort and seven case-control studies met the inclusion criteria. There were a total of 17,269 cardiovascular disease events, including 6265 stroke events, 10,806 coronary heart disease events, and 198 other cardiovascular disease events. A significant negative association was shown between soy intake and risk of cardiovascular disease (SRR = 0.84 95% CI: 0.75-0.94; p heterogeneity <0.001, I 2 = 71.4%). Subgroup meta-analyses indicated that a statistically significant protective effect was primarily observed in case-control studies and in Asian populations. There was a borderline significant association between intake of tofu and the risk of cardiovascular disease (SRR = 0.80, 95% CI: 0.64-1.00). A significant negative association was shown for the association between soy intake and risk of stroke (SRR = 0.82, 95% CI: 0.68-0.99) and coronary heart disease (SRR = 0.83, 95% CI: 0.72-0.95). There were no associations between soy isoflavones consumption and risk of cardiovascular disease, stroke, and coronary heart disease. Conclusion Overall evidence indicated that consumption of soy was negatively associated with the risk of cardiovascular disease, stroke, and coronary heart disease risk.
Kidney stones may increase the risk of coronary heart disease and stroke
Peng, Jian-Ping; Zheng, Hang
2017-01-01
Abstract Background: We aimed to quantitatively assess the potential relationship between kidney stones and coronary heart disease or stroke. Methods: A meta-analysis was conducted on eligibly studies published before 31 May 2016 in PubMed or Embase. The data were pooled, and the relationship was assessed by the random-effect model with inverse variance-weighted procedure. The results were expressed as relative risk (RR) with 95% confidence intervals (95%CI). Results: Eight studies of 11 cohorts (n = 11) were included in our analysis with 3,658,360 participants and 157,037 cases. We found that a history of kidney stones was associated with increased risk of coronary heart disease (CHD) (RR = 1.24; 95%CI: 1.14–1.36; I2 = 79.0%, n = 11); similar effect on myocardial infarction, a serious condition of CHD, was observed (RR = 1.24; 95%CI: 1.10–1.40; I2 = 80.4%, n = 8). We also found that a history of kidney stones may increase the risk of stroke (RR = 1.21, 95%CI: 1.06–1.38; I2 = 54.7%, n = 4). In subgroup analysis, the risk of coronary heart disease was higher in men (RR = 1.23, 95%CI: 1.02–1.49) while the risk for stroke was higher in women (RR = 1.12; 95%CI: 1.03–1.21). No obvious publications bias was detected (Egger test: P = .47). Conclusion: Kidney stones are associated with increased risk of coronary heart disease and stroke, and the effect may differ by sex. PMID:28834909
Devereux, Richard B; Bang, Casper N; Roman, Mary J; Palmieri, Vittorio; Boman, Kurt; Gerdts, Eva; Nieminen, Markku S; Papademetriou, Vasilios; Wachtell, Kristian; Hille, Darcy A; Dahlöf, Björn
2015-11-01
In the Losartan Intervention for End Point Reduction in Hypertension (LIFE) study, 4.8 years' losartan- versus atenolol-based antihypertensive treatment reduced left ventricular hypertrophy and cardiovascular end points, including cardiovascular death and stroke. However, there was no difference in myocardial infarction (MI), possibly related to greater reduction in myocardial oxygen demand by atenolol-based treatment. Myocardial oxygen demand was assessed indirectly by the left ventricular mass×wall stress×heart rate (triple product) in 905 LIFE participants. The triple product was included as time-varying covariate in Cox models assessing predictors of the LIFE primary composite end point (cardiovascular death, MI, or stroke), its individual components, and all-cause mortality. At baseline, the triple product in both treatment groups was, compared with normal adults, elevated in 70% of patients. During randomized treatment, the triple product was reduced more by atenolol, with prevalences of elevated triple product of 39% versus 51% on losartan (both P≤0.001). In Cox regression analyses adjusting for age, smoking, diabetes mellitus, and prior stroke, MI, and heart failure, 1 SD lower triple product was associated with 23% (95% confidence interval 13%-32%) fewer composite end points, 31% (18%-41%) less cardiovascular mortality, 30% (15%-41%) lower MI, and 22% (11%-33%) lower all-cause mortality (all P≤0.001), without association with stroke (P=0.34). Although losartan-based therapy reduced ventricular mass more, greater heart rate reduction with atenolol resulted in larger reduction of the triple product. Lower triple product during antihypertensive treatment was strongly, independently associated with lower rates of the LIFE primary composite end point, cardiovascular death, and MI, but not stroke. © 2015 American Heart Association, Inc.
Millard, Heather R; Musani, Solomon K; Dibaba, Daniel T; Talegawkar, Sameera A; Taylor, Herman A; Tucker, Katherine L; Bidulescu, Aurelian
2018-02-01
Several mechanisms have been described through which dietary intake of choline and its derivative betaine may be associated in both directions with subclinical atherosclerosis. We assessed the association of dietary intake of choline and betaine with cardiovascular risk and markers of subclinical cardiovascular disease. Data from 3924 Jackson Heart Study (JHS) African-American participants with complete food frequency questionnaire at baseline and follow-up measurements of heart disease measures were used. Multivariable linear regression models were employed to assess associations between choline and betaine intake with carotid intima-media thickness, coronary artery calcium, abdominal aortic calcium and left ventricular mass. Cox proportional hazards regression models were used to estimate associations with time to incident coronary heart disease (CHD), ischemic stroke and cardiovascular disease (CVD). During an average nine years of follow-up, 124 incident CHD events, 75 incident stroke events and 153 incident CVD events were documented. In women, greater choline intake was associated with lower left ventricular mass (p = 0.0006 for trend across choline quartiles) and with abdominal aortic calcium score. Among all JHS participants, there was a statistically significant inverse association between dietary choline intake and incident stroke, β = -0.33 (p = 0.04). Betaine intake was associated with greater risk of incident CHD when comparing the third quartile of intake with the lowest quartile of intake (HR 1.89, 95 % CI 1.14, 3.15). Among our African-American participants, higher dietary choline intake was associated with a lower risk of incident ischemic stroke, and thus putative dietary benefits. Higher dietary betaine intake was associated with a nonlinear higher risk of incident CHD.
Cavalcante, Denise de Fátima Barros; Brizon, Valéria Silva Cândido; Probst, Livia Fernandes; Meneghim, Marcelo de Castro; Pereira, Antonio Carlos; Ambrosano, Gláucia Maria Bovi
2018-01-01
The objective was to analyze whether socioeconomic factors related to the context and those related to the model of care-specifically the coverage of primary care by the Family Health Strategy (ESF)-had an impact on hospitalizations due to heart failure (HF) and stroke, in the State of São Paulo/Brazil between 1998 and 2013. A longitudinal ecological study involving 645 municipalities was conducted in the state of São Paulo/Brazil from 1998 to 2013, using the Hospital Information System (SIH-DataSUS database). The hospitalizations for primary care sensitive conditions: Stroke and heart failure (HF) that correspond to the International Classification of Diseases (ICD 10): I50, I63 to I67; I69, G45 to G46 were analyzed longitudinally during the period indicated regarding the percentage of people covered by the Family Health Program (PSF) adjusted for confounders (population size, gross domestic product -GDP and human development index- HDI). There was a significant decrease in the number of hospitalizations for heart failure and stroke per 10000 (inhabitants) in the period (p <0.0001), with a significant relationship with increased proportion of ESF (p <0.0001), and this remained significant even when possible confounders (population size, GDP and HDI) were included in the model (p <0.0001). GDP per capita was close to or higher than that if many European countries, which shows the relevance of the study. The health care model based on the Family Health Strategy positively impacted hospitalization indicators for heart failure and stroke, indicating that this model is effective in the prevention of primary care sensitive conditions.
Hippocampal volume and memory performance in children with perinatal stroke.
Gold, Jeffrey J; Trauner, Doris A
2014-01-01
Pediatric neurologists and neonatologists often are asked to predict cognitive outcome after perinatal brain injury (including likely memory and learning outcomes). However, relatively few data exist on how accurate predictions can be made. Furthermore, although the consequences of brain injury on hippocampal volume and memory performance have been studied extensively in adults, little work has been done in children. We measured the volume of the hippocampus in 27 children with perinatal stroke and 19 controls, and measured their performance on standardized verbal and non-verbal memory tests. We discovered the following: (1) As a group, children with perinatal stroke had smaller left and right hippocampi compared with control children. (2) Individually, children with perinatal stroke demonstrated 1 of 3 findings: no hippocampal loss, unilateral hippocampal loss, or bilateral hippocampal volume loss compared with control children. (3) Hippocampal volume inversely correlated with memory test performance in the perinatal stroke group, with smaller left and right hippocampal volumes related to poorer verbal and non-verbal memory test performance, respectively. (4) Seizures played a significant role in determining memory deficit and extent of hippocampal volume reduction in patients with perinatal stroke. These findings support the view that, in the developing brain, the left and right hippocampi preferentially support verbal and nonverbal memory respectively, a consistent finding in the adult literature but a subject of debate in the pediatric literature. This is the first work to report that children with focal brain injury incurred from perinatal stroke have volume reduction in the hippocampus and impairments in certain aspects of declarative memory. Copyright © 2014 Elsevier Inc. All rights reserved.
De Marco, Marina; de Simone, Giovanni; Roman, Mary J; Chinali, Marcello; Lee, Elisa T; Russell, Marie; Howard, Barbara V; Devereux, Richard B
2009-01-01
Prehypertension (defined by JNC-7) frequently evolves to hypertension (HTN) and increases cardiovascular risk. It is unclear whether metabolic and/or cardiac characteristics favor development of HTN in prehypertensive subjects. We evaluated baseline anthropometric, laboratory and echocardiographic characteristics of 625 untreated prehypertensive participants in the Strong Heart Study (SHS), without prevalent cardiovascular disease (63% women; 22% diabetes; mean age 59±7 years) to identify predictors of 4-year incidence of hypertension. Diabetes was assessed by ADA criteria and diabetes-specific definition of hypertension was used. Four-year incidence of HTN was 38%. Incident HTN was independently predicted by baseline systolic blood pressure (OR= 1.60 per 10 mmHg, 95% CI=1.30-2.00; p<0.0001), waist circumference (OR=1.10 per 10 cm, 95% CI=1.01-1.30; p=0.04) and diabetes (OR= 2.73, 95% CI=1.77-4.21; p<0.0001), with no significant effect for age, gender, HbA1c, HOMA index, CRP, fibrinogen, LDL-HDL cholesterol, tryglicerides, plasma creatinine or urine albumin/creatinine. Higher left ventricular mass index (OR=1.15 per 5 g/m2.7, 95% CI=1.01-1.25; p= 0.03) or stroke volume index (OR=1.25 per 5 ml/m2.04, 95% CI=1.10-1.50; p= 0.03) were also identified, together with baseline systolic blood pressure and presence of diabetes, as independent predictors of incident HTN, without additional predictive contribution from other anthropometric, metabolic or echocardiographic parameters (all p>0.10). Thus, progression to HTN in 38% of SHS pre-hypertensive participants could be predicted by higher left ventricular mass and stroke volume in addition to baseline systolic blood pressure and prevalent diabetes. PMID:19720957
2018-05-01
Heart involvement is the most important prognostic determinant in AL amyloidosis patients. Echocardiography is a cornerstone for the diagnosis and provides important prognostic information. We studied 754 patients with AL amyloidosis who underwent echocardiographic assessment at the Mayo Clinic, including a Doppler-derived measurement of stroke volume (SV) within 30 days of their diagnosis to explore the prognostic role of echocardiographic variables in the context of a well-established soluble cardiac biomarker staging system. Reproducibility of SV, myocardial contraction fraction, and left ventricular strain was assessed in a separate, yet comparable, study cohort of 150 patients from the Pavia Amyloidosis Center. The echocardiographic measures most predictive for overall survival were SV index <33 mL/min, myocardial contraction fraction <34%, and cardiac index <2.4 L/min/m 2 with respective hazard ratios (95% confidence intervals) of 2.95 (2.37-3.66), 2.36 (1.96-2.85), and 2.32 (1.91-2.80). For the subset that had left ventricular strain performed, the prognostic cut point was -14% (hazard ratios, 2.70; 95% confidence intervals, 1.84-3.96). Each parameter was independent of systolic blood pressure, Mayo staging system (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and troponin), and ejection fraction on multivariable analysis. Simple predictive models for survival, including biomarker staging along with SV index or left ventricular strain, were generated. SV index prognostic performance was similar to left ventricular strain in predicting survival in AL amyloidosis, independently of biomarker staging. Because SV index is routinely calculated and widely available, it could serve as the preferred echocardiographic measure to predict outcomes in AL amyloidosis patients. © 2018 American Heart Association, Inc.
Central and peripheral hemodynamic responses to passive limb movement: the role of arousal
Venturelli, Massimo; Amann, M.; McDaniel, J.; Trinity, J. D.; Fjeldstad, A. S.
2012-01-01
The exact role of arousal in central and peripheral hemodynamic responses to passive limb movement in humans is unclear but has been proposed as a potential contributor. Thus, we used a human model with no lower limb afferent feedback to determine the role of arousal on the hemodynamic response to passive leg movement. In nine people with a spinal cord injury, we compared central and peripheral hemodynamic and ventilatory responses to one-leg passive knee extension with and without visual feedback (M+VF and M-VF, respectively) as well as in a third trial with no movement or visual feedback but the perception of movement (F). Ventilation (V̇e), heart rate, stroke volume, cardiac output, mean arterial pressure, and leg blood flow (LBF) were evaluated during the three protocols. V̇e increased rapidly from baseline in M+VF (55 ± 11%), M-VF (63 ± 13%), and F (48 ± 12%) trials. Central hemodynamics (heart rate, stroke volume, cardiac output, and mean arterial pressure) were unchanged in all trials. LBF increased from baseline by 126 ± 18 ml/min in the M+VF protocol and 109 ± 23 ml/min in the M-VF protocol but was unchanged in the F protocol. Therefore, with the use of model that is devoid of afferent feedback from the legs, the results of this study reveal that, although arousal is invoked by passive movement or the thought of passive movement, as evidenced by the increase in V̇e, there is no central or peripheral hemodynamic impact of this increased neural activity. Additionally, this study revealed that a central hemodynamic response is not an obligatory component of movement-induced LBF. PMID:22003056
Russo, Cesare; Jin, Zhezhen; Palmieri, Vittorio; Homma, Shunichi; Rundek, Tatjana; Elkind, Mitchell S V; Sacco, Ralph L; Di Tullio, Marco R
2012-08-01
Increased arterial stiffness and wave reflection have been reported in heart failure with normal ejection fraction (HFNEF) and in asymptomatic left ventricular (LV) diastolic dysfunction, a precursor of HFNEF. It is unclear whether women, who have higher frequency of HFNEF, are more vulnerable than men to the deleterious effects of arterial stiffness on LV diastolic function. We investigated, in a large community-based cohort, whether sex differences exist in the relationship among arterial stiffness, wave reflection, and LV diastolic function. Arterial stiffness and wave reflection were assessed in 983 participants from the Cardiovascular Abnormalities and Brain Lesions study using applanation tonometry. The central pulse pressure/stroke volume index, total arterial compliance, pulse pressure amplification, and augmentation index were used as parameters of arterial stiffness and wave reflection. LV diastolic function was evaluated by 2-dimensional echocardiography and tissue-Doppler imaging. Arterial stiffness and wave reflection were greater in women compared with men, independent of body size and heart rate (all P<0.01), and showed inverse relationships with parameters of diastolic function in both sexes. Further adjustment for cardiovascular risk factors attenuated these relationships; however, a higher central pulse pressure/stroke volume index predicted LV diastolic dysfunction in women (odds ratio, 1.54; 95% confidence intervals, 1.03 to 2.30) and men (odds ratio, 2.09; 95% confidence interval, 1.30 to 3.39), independent of other risk factors. In conclusion, in our community-based cohort study, higher arterial stiffness was associated with worse LV diastolic function in men and women. Women's higher arterial stiffness, independent of body size, may contribute to their greater susceptibility to develop HFNEF.
Multi-Ethnic Study of Atherosclerosis (MESA)
2016-07-28
Atherosclerosis; Cardiovascular Diseases; Heart Diseases; Coronary Artery Disease; Coronary Disease; Stroke; Myocardial Infarction; Heart Failure; Diabetes Mellitus, Type 2; Hypertension; Diabetes Mellitus
Change of heart dimensions and function during pregnancy in goats.
Szaluś-Jordanow, Olga; Czopowicz, Michał; Witkowski, Lucjan; Moroz, Agata; Mickiewicz, Marcin; Frymus, Tadeusz; Markowska-Daniel, Iwona; Bagnicka, Emilia; Kaba, Jarosław
2018-03-08
The study aimed to evaluate the effect of pregnancy on heart diameters and function in goats. Transthoracic echocardiography of 12 female dairy goats of two Polish regional breeds was performed. A Mindray M7 diagnostic ultrasound system with Phased Array transducer was used. Simultaneously, electrocardiography was recorded. All animals were examined four times - at mating season, at the end of the first trimester, at the end of the second trimester and just before kidding. Eleven measurements were taken each time: aortic and left atrial diameter (AoD and LAD), right and left ventricular internal diameter in diastole (RVIDd and LVIDd), left ventricular internal diameter in systole (LVIDs), inter-ventricular septum thickness in diastole and systole (IVSd and IVSd) and left ventricular posterior wall in diastole and systole (LVPWd and LVPWs), maximum left and right ventricular outflow tract velocity (RVOT Vmax and LVOT Vmax). Nine consecutive measurements were derived: the ratio of the left atrial diameter to the aortic diameter (AoD/LAD), left ventricular fractional shortening (FS%), left ventricular ejection fraction (EF%), maximum outflow tract pressure gradients (RVOT PGmax and LVOT PGmax), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV), stroke volume (SV) and cardiac output (CO). HR, LAD, LVPWs, IVSs increased significantly in the first trimester. AoD and RVIDd were significantly higher around parturition. LVIDd, FS%, EF%, SV and CO rose both in the first and third trimester. No measurement decreased during pregnancy. The study confirms that pregnancy causes changes in the heart size and functioning. Copyright © 2018. Published by Elsevier Ltd.
Risk modelling study for carotid endarterectomy.
Kuhan, G; Gardiner, E D; Abidia, A F; Chetter, I C; Renwick, P M; Johnson, B F; Wilkinson, A R; McCollum, P T
2001-12-01
The aims of this study were to identify factors that influence the risk of stroke or death following carotid endarterectomy (CEA) and to develop a model to aid in comparative audit of vascular surgeons and units. A series of 839 CEAs performed by four vascular surgeons between 1992 and 1999 was analysed. Multiple logistic regression analysis was used to model the effect of 15 possible risk factors on the 30-day risk of stroke or death. Outcome was compared for four surgeons and two units after adjustment for the significant risk factors. The overall 30-day stroke or death rate was 3.9 per cent (29 of 741). Heart disease, diabetes and stroke were significant risk factors. The 30-day predicted stroke or death rates increased with increasing risk scores. The observed 30-day stroke or death rate was 3.9 per cent for both vascular units and varied from 3.0 to 4.2 per cent for the four vascular surgeons. Differences in the outcomes between the surgeons and vascular units did not reach statistical significance after risk adjustment. Diabetes, heart disease and stroke are significant risk factors for stroke or death following CEA. The risk score model identified patients at higher risk and aided in comparative audit.
Risk factors in various subtypes of ischemic stroke according to TOAST criteria.
Aquil, Nadia; Begum, Imtiaz; Ahmed, Arshia; Vohra, Ejaz Ahmed; Soomro, Bashir Ahmed
2011-05-01
To identify the frequency of risk factors in various subtypes of acute ischemic stroke according to TOAST criteria. Cross-sectional, observational study. Ziauddin Hospital, Karachi, from January to December 2007. Patients with acute ischemic stroke were enrolled. Studied variables included demographic profile, history of risk factors, physical and neurological examination, and investigations relevant with the objectives of the study. Findings were described as frequency percentages. Proportions of risk factors against subtypes was compared using chi-square test with significance at p < 0.05. Out of the 100 patients with acute ischemic stroke, mean age at presentation was 63.5 years. Risk factor distribution was hypertension in 85%, Diabetes mellitus in 49%, ischemic heart disease in 30%, dyslipedemia in 22%, smoking in 9%, atrial fibrillation in 5%, and previous history of stroke in 29%. The various subtypes of acute ischemic stroke were lacunar infarct in 43%, large artery atherosclerosis in 31%, cardioembolic type in 8%, stroke of other determined etiology in 1% and stroke of undetermined etiology in 18%. Hypertension and Diabetes were the most important risk factors in both large and small artery atherosclerosis. In patients with cardio-embolic stroke significant association was found with ischemic heart disease (p=0.01). Importance and relevance of risk factors evaluated for subtypes rather than ischemic stroke as a whole should be reflected in preventive efforts against the burden of ischemic stroke.
Fox, Christine K.; Sidney, Stephen; Fullerton, Heather J.
2014-01-01
Background and Purpose A better understanding of the stroke risk factors in children with congenital heart disease (CHD) could inform stroke prevention strategies. We analyzed pediatric stroke associated with CHD in a large community-based, case-control study. Methods From 2.5 million children (< 20 years) enrolled in a Northern California integrated healthcare plan, we identified ischemic and hemorrhagic strokes and randomly selected age and facility-matched stroke-free controls (3 per case). We determined exposure to CHD (diagnosed prior to stroke) and used conditional logistic regression to analyze stroke risk. Results CHD was identified in 15/412 cases (4%) versus 7/1,236 controls (0.6%). Children (28 days – 20 years) with CHD had 19-fold (Odds Ratio [OR] 19; 95% Confidence Interval [CI] 4.2, 83) increased stroke risk compared to controls. History of CHD surgery was associated with >30-fold increased risk of stroke (OR 31; CI 4, 241 compared to controls). After excluding peri-operative strokes, a history of CHD surgery still increased childhood stroke risk (OR 13; CI 1.5, 114). The majority of children with stroke and CHD were outpatient at the time of stroke, and almost half the cases who underwent cardiac surgery had their stroke >5 years after the most recent procedure. An estimated 7% of ischemic and 2% of hemorrhagic childhood strokes in the population were attributable to CHD. Conclusions CHD is an important childhood stroke risk factor. Children who undergo CHD surgery remain at elevated risk outside of the peri-operative period, and would benefit from optimized long-term stroke prevention strategies. PMID:25516197
Howard, George; McClure, Leslie A; Moy, Claudia S; Howard, Virginia J; Judd, Suzanne E; Yuan, Ya; Long, D Leann; Muntner, Paul; Safford, Monika M; Kleindorfer, Dawn O
2017-07-01
The standard for stroke risk stratification is the Framingham Stroke Risk Function (FSRF), an equation requiring an examination for blood pressure assessment, venipuncture for glucose assessment, and ECG to determine atrial fibrillation and heart disease. We assess a self-reported stroke risk function (SRSRF) to stratify stroke risk in comparison to the FSRF. Participants from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke) were evaluated at baseline and followed for incident stroke. The FSRF was calculated using directly assessed stroke risk factors. The SRSRF was calculated from 13 self-reported questions to exclude those with prevalent stroke and assess stroke risk. Proportional hazards analysis was used to assess incident stroke risk using the FSRF and SRSRF. Over an average 8.2-year follow-up, 939 of 23 983 participants had a stroke. The FSRF and SRSRF produced highly correlated risk scores ( r Spearman =0.852; 95% confidence interval, 0.849-0.856); however, the SRSRF had higher discrimination of stroke risk than the FSRF (c SRSRF =0.7266; 95% confidence interval, 0.7076-0.7457; c FSRF =0.7075; 95% confidence interval, 0.6877-0.7273; P =0.0038). The 10-year stroke risk in the highest decile of predicted risk was 11.1% for the FSRF and 13.4% for the SRSRF. A simple self-reported questionnaire can be used to identify those at high risk for stroke better than the gold standard FSRF. This instrument can be used clinically to easily identify individuals at high risk for stroke and also scientifically to identify a subpopulation enriched for stroke risk. © 2017 American Heart Association, Inc.
Symptomatic pulmonary embolism among stroke patients in Taiwan: a retrospective cohort study.
Chen, Chih-Chi; Lee, Tsong-Hai; Chung, Chia-Ying; Chang, Wei-Han; Hong, Jia-Pei; Huang, Li-Ting; Tang, Simon F T; Chen, Chih-Kuang
2012-01-01
Stroke patients are at particular risk for developing pulmonary embolism (PE), which is a cardiovascular emergency associated with a high mortality rate. Little information is available on symptomatic PE in Asian stroke patients. To determine the frequency of symptomatic PE in ischemic and hemorrhagic stroke patients; to identify common characteristics and risk factors of symptomatic PE in Taiwanese stroke patients; and to compare the difference between fatal PE and nonfatal PE among these stroke patients. This is a retrospective cohort study of stroke patients admitted between January 2002 and December 2009 to a tertiary referral center in Northern Taiwan. We used the International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify eligible patients. We determined annual frequency and risk factors of symptomatic PE. We also compared the difference between ischemic stroke patients with fatal and nonfatal PE. Among the admitted stroke patients, 21,129 (78.87%) had ischemic strokes and 5,662 (21.13 %) had hemorrhagic strokes. There were 14 (0.066%) ischemic and 1 hemorrhagic stroke (0.018%) patients included in this study. Of the recruited stroke patients, 64.29% had past heart disease history, especially atrial fibrillation (42.86%). Patients with fatal PE showed a significantly lower poststroke Glasgow Coma Scale (GCS) motor component than patients with nonfatal PE. Symptomatic PE is not common in stroke patients in Taiwan. Clinicians need to keep this fatal disease in mind, especially for persons with heart disease like atrial fibrillation. Stroke patients with impaired poststroke GCS motor components seemed to have a greater mortality risk if they have symptomatic PE.
Vafina, E Z; Abzalov, R A; Abzalov, N I; Nikitin, A S; Gulyakov, A A
2014-06-01
We analyzed parameters of the pumping function of the heart in rats subjected to enhanced motor activity after a preliminary 70-day hypokinesia under conditions of α- and β-adrenergic receptor stimulation with norepinephrine followed by blockade of β-adrenergic receptor with propranolol (obsidian) and α1-adrenergic receptors with doxazosin. After norepinephrine administration, the HR and cardiac output were higher in rats with enhanced physical activity after preliminary hypokinesia than in rats with low physical activity. After propranolol administration, stroke volume and cardiac output in 100-day-old rats with limited activity were lower, and HR higher was than in rats with enhanced physical activity after preliminary 70-day hypokinesia. After administration of doxazosin, rats with limited motor activity demonstrated more pronounced changes in HR than rats with enhanced physical activity after preliminary 70-day hypokinesia.
Cardiovascular responses of women to lower body negative pressure
NASA Technical Reports Server (NTRS)
Frey, M. A. B.; Mathes, K. L.; Hoffler, G. W.
1986-01-01
The effects of lower body negative pressure (LBNP) on the cardiovascular response of 20 women between 23-43 years are evaluated. Calf circumference and cardiovascular data were recorded for women in the follicular and luteal phases of the menstrual cycle at -30, -40, and -50 mm Hg LBNP. The data reveal that the two menstrual phases did not cause differences in the way women respond to LBNP. It is observed that during LBNP calf circumference is enlarged; transthoracic impedance, and heart rate are increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure, and cardiac output are reduced; and total peripheral resistance is elevated. The experimental data are compared to Montgomery et al. (1979). It is noted that the response of women to -50 mm Hg LBNP is similar to that of men; however, women adapt to stresses on the cardiovascular system with greater heart rate adjustments.
Sibir'ianov, A R; Sergeeva, N V; Podzolko, T Iu
2013-01-01
The present study was designed to study the influence of classical back and neck massage on the functional state of the cardiovascular system and its regulation under conditions of short-term physical loading in the healthy adolescents. It was shown that a course of classical massage promoted the reduction of arterial pressure in all children and the heart rate frequency in the boys. This effect was apparent as a reaction of blood circulation to the dosed physical exercises manifested as a rise in the heart rate frequency and stroke volume. The effects of classical massage were shown to be mediated through the alteration of the levels and mechanisms of regulation of the blood circulatory system and the enhancement of humoral and metabolic segmental sympathetic influences associated with the adaptation to the impact of massage therapy.
[Heart rate and energy expenditure during extravehicular activity in different time of day].
Stepanova, S I; Katuntsev, V P; Osipov, Iu Iu; Galichiĭ, V A
2013-01-01
The article discusses the comparative heart rate (HR) characteristics associated with day and night extravehicular activities (EVA). HR was commonly higher in the night but not in the daytime. Presumably, the reason is psychological and physiological challenges of the night work on the background of natural performance decrement. These circumstances could lead to elevation of psychic tension and, consequently, increase of heartbeats to a greater extent as compared with daytime EVA. According to the correlation analysis data, the pattern of HR relation to physical loads evaluated by energy expenditure in the daytime was other than at night, i.e. it was positive unlike the nighttime correlation. We cannot exclude it that in the daytime increase in cardiac output (CO) in response to physical work was largely due to increase in HR, whereas it was stroke volume that dominated during night work; at least, it could support CO fully in the periods of low loading.
Bio-logging of physiological parameters in higher marine vertebrates
NASA Astrophysics Data System (ADS)
Ponganis, Paul J.
2007-02-01
Bio-logging of physiological parameters in higher marine vertebrates had its origins in the field of bio-telemetry in the 1960s and 1970s. The development of microprocessor technology allowed its first application to bio-logging investigations of Weddell seal diving physiology in the early 1980s. Since that time, with the use of increased memory capacity, new sensor technology, and novel data processing techniques, investigators have examined heart rate, temperature, swim speed, stroke frequency, stomach function (gastric pH and motility), heat flux, muscle oxygenation, respiratory rate, diving air volume, and oxygen partial pressure (P) during diving. Swim speed, heart rate, and body temperature have been the most commonly studied parameters. Bio-logging investigation of pressure effects has only been conducted with the use of blood samplers and nitrogen analyses on animals diving at isolated dive holes. The advantages/disadvantages and limitations of recording techniques, probe placement, calibration techniques, and study conditions are reviewed.
NASA Astrophysics Data System (ADS)
Ford, Steven J.; Deán-Ben, Xosé L.; Razansky, Daniel
2015-03-01
The fast heart rate (~7 Hz) of the mouse makes cardiac imaging and functional analysis difficult when studying mouse models of cardiovascular disease, and cannot be done truly in real-time and 3D using established imaging modalities. Optoacoustic imaging, on the other hand, provides ultra-fast imaging at up to 50 volumetric frames per second, allowing for acquisition of several frames per mouse cardiac cycle. In this study, we combined a recently-developed 3D optoacoustic imaging array with novel analytical techniques to assess cardiac function and perfusion dynamics of the mouse heart at high, 4D spatiotemporal resolution. In brief, the heart of an anesthetized mouse was imaged over a series of multiple volumetric frames. In another experiment, an intravenous bolus of indocyanine green (ICG) was injected and its distribution was subsequently imaged in the heart. Unique temporal features of the cardiac cycle and ICG distribution profiles were used to segment the heart from background and to assess cardiac function. The 3D nature of the experimental data allowed for determination of cardiac volumes at ~7-8 frames per mouse cardiac cycle, providing important cardiac function parameters (e.g., stroke volume, ejection fraction) on a beat-by-beat basis, which has been previously unachieved by any other cardiac imaging modality. Furthermore, ICG distribution dynamics allowed for the determination of pulmonary transit time and thus additional quantitative measures of cardiovascular function. This work demonstrates the potential for optoacoustic cardiac imaging and is expected to have a major contribution toward future preclinical studies of animal models of cardiovascular health and disease.
Umesawa, Mitsumasa; Iso, Hiroyasu; Date, Chigusa; Yamamoto, Akio; Toyoshima, Hideaki; Watanabe, Yoshiyuki; Kikuchi, Shogo; Koizumi, Akio; Kondo, Takaaki; Inaba, Yutaka; Tanabe, Naohito; Tamakoshi, Akiko
2008-07-01
Limited evidence is available about the relations between sodium and potassium intakes and cardiovascular disease in the general population. The objective was to investigate relations between sodium and potassium intakes and cardiovascular disease in Asian populations whose mean sodium intake is generally high. Between 1988 and 1990, a total of 58,730 Japanese subjects (n = 23,119 men and 35,611 women) aged 40-79 y with no history of stroke, coronary heart disease, or cancer completed a lifestyle questionnaire including food intake frequency under the Japan Collaborative Cohort Study for Evaluation of Cancer Risk sponsored by the Ministry of Education, Sports and Science. After 745,161 person-years of follow-up, we documented 986 deaths from stroke (153 subarachnoid hemorrhages, 227 intraparenchymal hemorrhages, and 510 ischemic strokes) and 424 deaths from coronary heart disease. Sodium intake was positively associated with mortality from total stroke, ischemic stroke, and total cardiovascular disease. The multivariable hazard ratio for the highest versus the lowest quintiles of sodium intake after adjustment for age, sex, and cardiovascular disease risk factors was 1.55 (95% CI: 1.21, 2.00; P for trend < 0.001) for total stroke, 2.04 (95% CI: 1.41, 2.94; P for trend < 0.001) for ischemic stroke, and 1.42 (95% CI: 1.20, 1.69; P for trend < 0.001) for total cardiovascular disease. Potassium intake was inversely associated with mortality from coronary heart disease and total cardiovascular disease. The multivariable hazard ratio for the highest versus the lowest quintiles of potassium intake was 0.65 (95% CI: 0.39, 1.06; P for trend = 0.083) for coronary heart disease and 0.73 (95% CI: 0.59, 0.92; P for trend = 0.018) for total cardiovascular disease, and these associations were more evident for women than for men. A high sodium intake and a low potassium intake may increase the risk of mortality from cardiovascular disease.
Sickle cell trait and incident ischemic stroke in the Atherosclerosis Risk in Communities study.
Caughey, Melissa C; Loehr, Laura R; Key, Nigel S; Derebail, Vimal K; Gottesman, Rebecca F; Kshirsagar, Abhijit V; Grove, Megan L; Heiss, Gerardo
2014-10-01
Numerous case reports describe stroke in individuals with sickle cell trait (SCT) in the absence of traditional risk factors for cerebrovascular disease. To date, no prospective epidemiological studies have investigated this association. A population-based sample of blacks (n=3497; mean age=54 years; female=62%) was followed from 1987 to 2011 in the Atherosclerosis Risk in Communities (ARIC) study, contributing a total of 65 371 person-years. Hazard ratios and incidence rate differences for ischemic stroke were estimated, contrasting SCT to homozygous hemoglobin A. Models were adjusted for age, sex, smoking, diabetes mellitus, hypertension, total cholesterol, atrial fibrillation, and coronary heart disease. SCT was identified in 223 (6.4%) participants. During a median follow-up of 22 years, 401 subjects experienced incident stroke (89% ischemic). Incident ischemic stroke was more frequent among those with SCT (13%) than those with homozygous hemoglobin A (10%). SCT was associated with an ischemic stroke hazard ratio of 1.4 (1.0-2.0) and an incidence rate difference amounting to 1.9 (0.4-3.8) extra strokes per 1000 person-years. We observed an increased risk of ischemic stroke in blacks with SCT. Further investigation of the incidence and pathophysiology of stroke in patients with SCT is warranted. © 2014 American Heart Association, Inc.
Sieslack, Anne K; Dziallas, Peter; Nolte, Ingo; Wefstaedt, Patrick; Hungerbühler, Stephan O
2014-10-12
Right ventricular (RV) volume and function are important diagnostic and prognostic factors in dogs with primary or secondary right-sided heart failure. The complex shape of the right ventricle and its retrosternal position make the quantification of its volume difficult. For that reason, only few studies exist, which deal with the determination of RV volume parameters. In human medicine cardiac magnetic resonance imaging (CMRI) is considered to be the reference technique for RV volumetric measurement (Nat Rev Cardiol 7(10):551-563, 2010), but cardiac computed tomography (CCT) and three-dimensional echocardiography (3DE) are other non-invasive methods feasible for RV volume quantification. The purpose of this study was the comparison of 3DE and CCT with CMRI, the gold standard for RV volumetric quantification. 3DE showed significant lower and CCT significant higher right ventricular volumes than CMRI. Both techniques showed very good correlations (R > 0.8) with CMRI for the volumetric parameters end-diastolic volume (EDV) and end-systolic volume (ESV). Ejection fraction (EF) and stroke volume (SV) were not different when considering CCT and CMRI, whereas 3DE showed a significant higher EF and lower SV than CMRI. The 3DE values showed excellent intra-observer variability (<3%) and still acceptable inter-observer variability (<13%). CCT provides an accurate image quality of the right ventricle with comparable results to the reference method CMRI. CCT overestimates the RV volumes; therefore, it is not an interchangeable method, having the disadvantage as well of needing general anaesthesia. 3DE underestimated the RV-Volumes, which could be explained by the worse image resolution. The excellent correlation between the methods indicates a close relationship between 3DE and CMRI although not directly comparable. 3DE is a promising technique for RV volumetric quantification, but further studies in awake dogs and dogs with heart disease are necessary to evaluate its usefulness in veterinary cardiology.
Human Physiology in an Aquatic Environment.
Pendergast, David R; Moon, Richard E; Krasney, John J; Held, Heather E; Zamparo, Paola
2015-09-20
Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system. Copyright © 2015 John Wiley & Sons, Inc.
Stroke Risk and Mortality in Patients With Ventricular Assist Devices.
Parikh, Neal S; Cool, Joséphine; Karas, Maria G; Boehme, Amelia K; Kamel, Hooman
2016-11-01
Ventricular assist devices (VADs) have advanced the management of end-stage heart failure. However, these devices are associated with hemorrhagic and thrombotic complications, including stroke. We assessed the incidence, risk factors, and outcomes of ischemic and hemorrhagic stroke after VAD placement. Using administrative claims data from acute care hospitals in California, Florida, and New York from 2005 to 2013, we identified patients who underwent VAD placement, defined by the International Classification of Diseases, Ninth Revision, Clinical Modification code 37.66. Ischemic and hemorrhagic strokes were identified by previously validated coding algorithms. We used survival statistics to determine the incidence rates and Cox proportional hazard analyses to examine the associations. Among 1813 patients, we identified 201 ischemic strokes and 116 hemorrhagic strokes during 3.4 (±2.0) years of follow-up after implantation of a VAD. The incidence of stroke was 8.7% per year (95% confidence interval [CI], 7.7-9.7). The annual incidence of ischemic stroke (5.5%; 95% CI, 4.8-6.4) was nearly double that of hemorrhagic stroke (3.1%; 95% CI, 2.6-3.8). Women faced a higher hazard of stroke than men (hazard ratio, 1.6; 95% CI, 1.2-2.1), particularly hemorrhagic stroke (hazard ratio, 2.2; 95% CI, 1.4-3.4). Stroke was strongly associated with subsequent in-hospital mortality (hazard ratio, 6.1; 95% CI, 4.6-7.9). The incidence of stroke after VAD implantation was 8.7% per year, and incident stroke was strongly associated with subsequent in-hospital mortality. Notably, ischemic stroke occurred at nearly twice the rate of hemorrhagic stroke. Women seemed to face a higher risk for hemorrhagic stroke than men. © 2016 American Heart Association, Inc.
Cardiac hypertrophy limits infarct expansion after myocardial infarction in mice.
Iismaa, Siiri E; Li, Ming; Kesteven, Scott; Wu, Jianxin; Chan, Andrea Y; Holman, Sara R; Calvert, John W; Haq, Ahtesham Ul; Nicks, Amy M; Naqvi, Nawazish; Husain, Ahsan; Feneley, Michael P; Graham, Robert M
2018-04-17
We have previously demonstrated that adult transgenic C57BL/6J mice with CM-restricted overexpression of the dominant negative W v mutant protein (dn-c-kit-Tg) respond to pressure overload with robust cardiomyocyte (CM) cell cycle entry. Here, we tested if outcomes after myocardial infarction (MI) due to coronary artery ligation are improved in this transgenic model. Compared to non-transgenic littermates (NTLs), adult male dn-c-kit-Tg mice displayed CM hypertrophy and concentric left ventricular (LV) hypertrophy in the absence of an increase in workload. Stroke volume and cardiac output were preserved and LV wall stress was markedly lower than that in NTLs, leading to a more energy-efficient heart. In response to MI, infarct size in adult (16-week old) dn-c-kit-Tg hearts was similar to that of NTL after 24 h but was half that in NTL hearts 12 weeks post-MI. Cumulative CM cell cycle entry was only modestly increased in dn-c-kit-Tg hearts. However, dn-c-kit-Tg mice were more resistant to infarct expansion, adverse LV remodelling and contractile dysfunction, and suffered no early death from LV rupture, relative to NTL mice. Thus, pre-existing cardiac hypertrophy lowers wall stress in dn-c-kit-Tg hearts, limits infarct expansion and prevents death from myocardial rupture.
NASA Astrophysics Data System (ADS)
Jenkins, Michael W.; Peterson, Lindsy; Gu, Shi; Gargesha, Madhusudhana; Wilson, David L.; Watanabe, Michiko; Rollins, Andrew M.
2010-11-01
Hemodynamics is thought to play a major role in heart development, yet tools to quantitatively assess hemodynamics in the embryo are sorely lacking. The especially challenging analysis of hemodynamics in the early embryo requires new technology. Small changes in blood flow could indicate when anomalies are initiated even before structural changes can be detected. Furthermore, small changes in the early embryo that affect blood flow could lead to profound abnormalities at later stages. We present a demonstration of 4-D Doppler optical coherence tomography (OCT) imaging of structure and flow, and present several new hemodynamic measurements on embryonic avian hearts at early stages prior to the formation of the four chambers. Using 4-D data, pulsed Doppler measurements could accurately be attained in the inflow and outflow of the heart tube. Also, by employing an en-face slice from the 4-D Doppler image set, measurements of stroke volume and cardiac output are obtained without the need to determine absolute velocity. Finally, an image plane orthogonal to the blood flow is used to determine shear stress by calculating the velocity gradient normal to the endocardium. Hemodynamic measurements will be crucial to identifying genetic and environmental factors that lead to congenital heart defects.
Muntner, Paul; Whittle, Jeff; Lynch, Amy I.; Colantonio, Lisandro D.; Simpson, Lara M.; Einhorn, Paula T.; Levitan, Emily B.; Whelton, Paul K; Cushman, William C.; Louis, Gail T.; Davis, Barry R.; Oparil, Suzanne
2016-01-01
Background Variability of blood pressure (BP) across outpatient visits is frequently dismissed as random fluctuation around a patient’s underlying BP. Objective: Examine the association between visit-to-visit variability (VVV) of systolic and diastolic BP (SBP and DBP) on cardiovascular disease and mortality outcomes. Design Prospective cohort study Setting Post-hoc analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Participants 25,814 ALLHAT participants. Measurements VVV of SBP was defined as the standard deviation (SD) across BP measurements obtained at 7 visits conducted from 6 to 28 months following ALLHAT enrollment. Participants free of cardiovascular disease events during the first 28 months of follow-up were followed from the month 28 study visit through the end of active ALLHAT follow-up. Outcomes included fatal coronary heart disease or non-fatal myocardial infarction, all-cause mortality, stroke and heart failure. Results There were 1194 cases of fatal CHD or non-fatal MI, 1948 deaths, 606 cases of stroke and 921 cases of heart failure during follow-up. After multivariable adjustment including mean SBP, the hazard ratio comparing participants in the highest versus lowest quintile of SD of SBP (≥14.4 mmHg versus <6.5 mmHg) was 1.30 (1.06–1.59) for fatal coronary heart disease or non-fatal myocardial infarction, 1.58 (1.32–1.90) for all-cause mortality, 1.46 (1.06–2.01) for stroke, and 1.25 (0.97–1.61) for heart failure. Higher VVV of DBP was also associated with cardiovascular disease events and mortality. Limitations Long-term outcomes were not available. Conclusions Higher VVV of SBP is associated with increased cardiovascular disease and mortality risk. Future studies should examine whether reducing VVV of BP lowers this risk. Primary funding source National Institutes of Health PMID:26215765
Predictors of short- and long-term mortality in first-ever ischaemic older stroke patients.
Hsu, Chia-Yu; Hu, Gwo-Chi; Chen, Yi-Min; Chen, Chiu-Hsiang; Hu, Yu-Ning
2013-12-01
Predictors of short- and long-term all-cause mortality of older stroke patients were explored. Cox regression models were used to estimate the relative risk and 95% confidence intervals (CI) in the database entries of 636 older stroke patients aged 70 years and over. National Institutes of Health Stroke Scale (NIHSS) score on admission, age and coronary heart disease were significantly associated with 28-day death. The hazard ratios for the predictors of long-term mortality were as follows: NIHSS score, 1.1 (95% CI: 1.07-1.1); serum glucose level, 1.08 (95% CI: 1.01-1.2); serum triglyceride level, 0.6 (95% CI: 0.4-0.8); age, 1.04 (95% CI: 1.01-1.08); and coronary heart disease, 2.7 (95% CI: 1.4-5.4). NIHSS score on admission, age and coronary heart disease are independent predictors of short- and long-term mortality. Higher glucose and lower triglyceride level are significantly associated with the long-term mortality. © 2013 The Authors. Australasian Journal on Ageing © 2013 ACOTA.
[Cerebrovascular risk factors seen in a university hospital].
Hernández Chávez, M; Samsó Zepeda, C; López Espejo, M; Escobar Henríquez, R; Mesa Latorre, T
2014-09-01
Risk factors (RF) in pediatric stroke differ from those of adults, and they include a wide range of diseases such as heart disease, infections, leukemias, and inborn errors of metabolism. To describe RF for ischemic stroke in a pediatric population, and to examine the relationship of RF with age, sex and type of stroke. An analysis was made of database of 114 children and adolescents with ischemic stroke from January 2003 to July 2012. Risk factors were stratified into 6 categories and ischemic strokes were classified as arterial and venous. We compared the RF with age, sex, and type of stroke (chi2 and OR). The median age was 2.5 years, with 74 (62.2%) males. No RF was identified in 7.9% of patients, and 67% had more than one RF. The most common RF were acute systemic diseases (56.1%), heart disease (35.1%), and chronic systemic diseases (29.8%). There was a statistically significant association between acute systemic disease and age less than 5 years (P<.001), and between chronic systemic disease and age 5 years or more (P<.02). The RF of heart disease was associated with arterial infarction (P<.05), and the acute head and neck disease RF was associated with venous infarction (P<.05). The RF for ischemic stroke are multiple in the pediatric population, and some of them are associated with a specific age and type of stroke. The detection of these factors may help in the primary prevention of people at risk, an early diagnosis, and treatment and prevention of recurrences. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Bonaca, Marc P; Goto, Shinya; Bhatt, Deepak L; Steg, P Gabriel; Storey, Robert F; Cohen, Marc; Goodrich, Erica; Mauri, Laura; Ophuis, Ton Oude; Ruda, Mikhail; Špinar, Jindřich; Seung, Ki-Bae; Hu, Dayi; Dalby, Anthony J; Jensen, Eva; Held, Peter; Morrow, David A; Braunwald, Eugene; Sabatine, Marc S
2016-09-20
In the PEGASUS-TIMI 54 trial (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54), ticagrelor reduced the risk of major adverse cardiovascular events when added to low-dose aspirin in stable patients with prior myocardial infarction, resulting in the approval of ticagrelor 60 mg twice daily for long-term secondary prevention. We investigated the incidence of stroke, outcomes after stroke, and the efficacy of ticagrelor focusing on the approved 60 mg twice daily dose for reducing stroke in this population. Patients were followed for a median of 33 months. Stroke events were adjudicated by a central committee. Data from similar trials were combined using meta-analysis. Of 14 112 patients randomly assigned to placebo or ticagrelor 60 mg, 213 experienced a stroke; 85% of these strokes were ischemic. A total of 18% of strokes were fatal and another 15% led to either moderate or severe disability at 30 days. Ticagrelor significantly reduced the risk of stroke (hazard ratio, 0.75; 95% confidence interval, 0.57-0.98; P=0.034), driven by a reduction in ischemic stroke (hazard ratio, 0.76; 95% confidence interval, 0.56-1.02). Hemorrhagic stroke occurred in 9 patients on placebo and 8 patients on ticagrelor. A meta-analysis across 4 placebo-controlled trials of more intensive antiplatelet therapy in 44 816 patients with coronary disease confirmed a marked reduction in ischemic stroke (hazard ratio, 0.66; 95% confidence interval, 0.54-0.81; P=0.0001). High-risk patients with prior myocardial infarction are at risk for stroke, approximately one-third of which are fatal or lead to moderate-to-severe disability. The addition of ticagrelor 60 mg twice daily significantly reduced this risk without an excess of hemorrhagic stroke but with more major bleeding. In high-risk patients with coronary disease, more intensive antiplatelet therapy should be considered not only to reduce the risk of coronary events, but also of stroke. URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01225562. © 2016 American Heart Association, Inc.
Hausken, T; Li, X N; Goldman, B; Leotta, D; Ødegaard, S; Martin, R W
2001-07-01
To develop a non-invasive method for evaluating gastric emptying and duodenogastric reflux stroke volumes using three-dimensional (3D) guided digital color Doppler imaging. The technique involved color Doppler digital images of transpyloric flow in which the 3D position and orientation of the images were known by using a magnetic location system. In vitro, the system was found to slightly underestimate the reference flow (by average 8.8%). In vivo (five volunteers), stroke volume of gastric emptying episodes lasted on average only 0.69 s with a volume on average of 4.3 ml (range 1.1-7.4 ml), and duodenogastric reflux episodes on average 1.4 s with a volume of 8.3 ml (range 1.3-14.1 ml). With the appropriate instrument settings, orientation determined color Doppler can be used for stroke volume quantification of gastric emptying and duodenogastric reflux episodes.
Healthy Heart Collaboration and Developed Toolkit
Impact: EPA is raising awareness of heart disease and its link to air pollution and other environmental factors as a partner in Million Hearts, a national initiative to prevent heart attacks and strokes. The talk will provide an up to date review of the evidence linking air poll...
Impact of Infarct Size on Blood Pressure in Young Patients with Acute Stroke.
Bonardo, Pablo; Pantiú, Fátima; Ferraro, Martín; Chertcoff, Anibal; Bandeo, Lucrecia; Cejas, Luciana León; Pacha, Sol; Roca, Claudia Uribe; Rugilo, Carlos; Pardal, Manuel Maria Fernández; Reisin, Ricardo
2018-06-01
Hypertension can be found in up to 80% of patients with acute stroke. Many factors have been related to this phenomenon such as age, history of hypertension, and stroke severity. The aim of our study was to determine the relationship between infarct volume and blood pressure, at admission, in young patients with acute ischemic stroke. Patients younger than 55 years old admitted within 24 hours of ischemic stroke were included. Socio-demographic variables, systolic blood pressure, diastolic blood pressure, and infarct volume at admission were assessed. Statistical analysis: mean and SEM for quantitative variables, percentages for qualitative, and Spearman correlations ( p value < 0.05 was considered statistically significant). Twenty-two patients (12 men), mean age: 44.64 ± 1.62 years. The most frequent vascular risk factors were: hypertension, smoking, and overweight (40.9%). Mean systolic and diastolic blood pressure on admission were: 143.27 ± 6.57 mmHg and 85.14 ± 3.62 mmHg, respectively. Infarct volume: 11.55 ± 4.74 ml. Spearman correlations: systolic blood pressure and infarct volume: p = 0.15 r : -0.317; diastolic blood pressure and infarct volume: p = 0.738 r: -0.76. In our series of young patients with acute ischemic stroke, large infarct volume was not associated with high blood pressure at admission.
Hautvast, Gilion L T F; Salton, Carol J; Chuang, Michael L; Breeuwer, Marcel; O'Donnell, Christopher J; Manning, Warren J
2012-05-01
Quantitative analysis of short-axis functional cardiac magnetic resonance images can be performed using automatic contour detection methods. The resulting myocardial contours must be reviewed and possibly corrected, which can be time-consuming, particularly when performed across all cardiac phases. We quantified the impact of manual contour corrections on both analysis time and quantitative measurements obtained from left ventricular short-axis cine images acquired from 1555 participants of the Framingham Heart Study Offspring cohort using computer-aided contour detection methods. The total analysis time for a single case was 7.6 ± 1.7 min for an average of 221 ± 36 myocardial contours per participant. This included 4.8 ± 1.6 min for manual contour correction of 2% of all automatically detected endocardial contours and 8% of all automatically detected epicardial contours. However, the impact of these corrections on global left ventricular parameters was limited, introducing differences of 0.4 ± 4.1 mL for end-diastolic volume, -0.3 ± 2.9 mL for end-systolic volume, 0.7 ± 3.1 mL for stroke volume, and 0.3 ± 1.8% for ejection fraction. We conclude that left ventricular functional parameters can be obtained under 5 min from short-axis functional cardiac magnetic resonance images using automatic contour detection methods. Manual correction more than doubles analysis time, with minimal impact on left ventricular volumes and ejection fraction. Copyright © 2011 Wiley Periodicals, Inc.
Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.
Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E
2016-01-01
The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter volumes in these clusters related to verbal working memory capacity, but not other cognitive functions. Further, grey matter volumes in these areas were greater in stroke survivors than healthy control subjects. To confirm this result, 10 chronic left hemisphere stroke survivors with no history of aphasia were identified. Grey matter volumes in right temporoparietal clusters were greater in stroke survivors with aphasia compared to those without history of aphasia. These findings suggest that the grey matter structure of right hemisphere posterior dorsal stream language homologues independently contributes to language production abilities in chronic left hemisphere stroke, and that these areas may undergo hypertrophy after a stroke causing aphasia. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
[Broad ischemic stroke revealing infective endocarditis in a young patient: about a case].
Ravelosaona, Fanomezantsoa Noella; Razafimahefa, Julien; Randrianasolo, Rahamefy Odilon; Rakotoarimanana, Solofonirina; Tehindrazanarivelo, Djacoba Alain
2016-01-01
Broad ischemic stroke is mainly due to a cardiac embolus or to an atheromatous plaque. In young subjects, one of the main causes of ischemic stroke (broad ischemic stroke in particolar) is embolic heart disease including infective endocarditis. Infective endocarditis is a contraindication against the anticoagulant therapy (which is indicated for the treatment of embolic heart disease complicated by ischemic stroke). One neurologic complications of infective endocarditis is ischemic stroke which often occurs in multiple sites. We here report the case of a 44-year old man with afebrile acute onset of severe left hemiplegia associated with a sistolic mitral murmur, who had fever in hospital on day 5 with no other obvious source of infection present. Brain CT scan showed full broad ischaemic stroke of the right middle cerebral artery territory and doppler ultrasound, performed after stroke onset, showed infective endocarditis affecting the small mitral valve. He was treated with 4 weeks of antibiotic therapy without anticoagulant therapy ; evolution was marked by the disappearance of mitral valve vegetations and by movement sequelae involving the left side of the body. In practical terms, our problem was the onset of the fever which didn't accompany or pre-exist patient's deficit, leading us to the misdiagnosis of ischemic stroke of cardioembolic origin. This case study underlines the importance of doppler ultrasound, in the diagnosis of all broad ischemic strokes, especially superficial, before starting anticoagulant therapy.
Understanding the Role of Autoimmune Disorders on the Initial Presentation of Cardiovascular Disease
2015-04-20
Myocardial Infarction; Ischemic Stroke; Stroke; Subarachnoid Haemorrhage; Venous Thrombosis; Transient Ischemic Attack; Stable Angina Pectoris; Unstable Angina; Heart Failure; Peripheral Arterial Disease; Abdominal Aortic Aneurysm
Resting Heart Rate Predicts Depression and Cognition Early after Ischemic Stroke: A Pilot Study.
Tessier, Arnaud; Sibon, Igor; Poli, Mathilde; Audiffren, Michel; Allard, Michèle; Pfeuty, Micha
2017-10-01
Early detection of poststroke depression (PSD) and cognitive impairment (PSCI) remains challenging. It is well documented that the function of autonomic nervous system is associated with depression and cognition. However, their relationship has never been investigated in the early poststroke phase. This pilot study aimed at determining whether resting heart rate (HR) parameters measured in early poststroke phase (1) are associated with early-phase measures of depression and cognition and (2) could be used as new tools for early objective prediction of PSD or PSCI, which could be applicable to patients unable to answer usual questionnaires. Fifty-four patients with first-ever ischemic stroke, without cardiac arrhythmia, were assessed for resting HR and heart rate variability (HRV) within the first week after stroke and for depression and cognition during the first week and at 3 months after stroke. Multiple regression analyses controlled for age, gender, and stroke severity revealed that higher HR, lower HRV, and higher sympathovagal balance (low-frequency/high-frequency ratio of HRV) were associated with higher severity of depressive symptoms within the first week after stroke. Furthermore, higher sympathovagal balance in early phase predicted higher severity of depressive symptoms at the 3-month follow-up, whereas higher HR and lower HRV in early phase predicted lower global cognitive functioning at the 3-month follow-up. Resting HR measurements obtained in early poststroke phase could serve as an objective tool, applicable to patients unable to complete questionnaires, to help in the early prediction of PSD and PSCI. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.
Ben Assayag, Einor; Eldor, Roy; Korczyn, Amos D; Kliper, Efrat; Shenhar-Tsarfaty, Shani; Tene, Oren; Molad, Jeremy; Shapira, Itzhak; Berliner, Shlomo; Volfson, Viki; Shopin, Ludmila; Strauss, Yehuda; Hallevi, Hen; Bornstein, Natan M; Auriel, Eitan
2017-09-01
Type 2 diabetes mellitus (T2DM) is associated with diseases of the brain, kidney, and vasculature. However, the relationship between T2DM, chronic kidney disease, brain alterations, and cognitive function after stroke is unknown. We aimed to evaluate the inter-relationship between T2DM, impaired renal function, brain pathology on imaging, and cognitive decline in a longitudinal poststroke cohort. The TABASCO (Tel Aviv brain acute stroke cohort) is a prospective cohort of stroke/transient ischemic attack survivors. The volume and white matter integrity, ischemic lesions, and brain and hippocampal volumes were measured at baseline using 3-T MRI. Cognitive tests were performed on 507 patients, who were diagnosed as having mild cognitive impairment, dementia, or being cognitively intact after 24 months. At baseline, T2DM and impaired renal function (estimated creatinine clearance [eCCl] <60 mL/min) were associated with smaller brain and hippocampal volumes, reduced cortical thickness, and worse white matter microstructural integrity. Two years later, both T2DM and eCCl <60 mL/min were associated with poorer cognitive scores, and 19.7% of the participants developed cognitive decline (mild cognitive impairment or dementia). Multiple analysis, controlling for age, sex, education, and apolipoprotein E4, showed a significant association of both T2DM and eCCl <60 mL/min with cognitive decline. Having both conditions doubled the risk compared with patients with T2DM or eCCl <60 mL/min alone and almost quadrupled the risk compared with patients without either abnormality. T2DM and impaired renal function are independently associated with abnormal brain structure, as well as poorer performance in cognitive tests, 2 years after stroke. The presence of both conditions quadruples the risk for cognitive decline. T2DM and lower eCCl have an independent and additive effect on brain atrophy and the risk of cognitive decline. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01926691. © 2017 American Heart Association, Inc.
Xu, Yan-Hong; Wang, Xing-De; Yang, Jia-Jun; Zhou, Li; Pan, Yong-Chao
2016-01-01
Autonomic dysfunction is common after stroke, which is correlated with unfavorable outcome. Phase-rectified signal averaging is a newly developed technique for assessing cardiac autonomic function, by detecting sympathetic and vagal nerve activity separately through calculating acceleration capacity (AC) and deceleration capacity (DC) of heart rate. In this study, we used this technique for the first time to investigate the cardiac autonomic function of patients with acute hemispheric ischemic stroke. A 24-hour Holter monitoring was performed in 63 patients with first-ever acute ischemic stroke in hemisphere and sinus rhythm, as well as in 50 controls with high risk of stroke. DC, AC, heart rate variability parameters, standard deviation of all normal-to-normal intervals (SDNN), and square root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals (RMSSD) were calculated. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the severity of stroke. We analyzed the changes of DC, AC, SDNN, and RMSSD and also studied the correlations between these parameters and NIHSS scores. The R-R (R wave to R wave on electrocardiogram) intervals, DC, AC, and SDNN in the cerebral infarction group were lower than those in controls (P=0.003, P=0.002, P=0.006, and P=0.043), but the difference of RMSSD and the D-value and ratio between absolute value of AC (|AC|) and DC were not statistically significant compared with those in controls. The DC of the infarction group was significantly correlated with |AC|, SDNN, and RMSSD (r=0.857, r=0.619, and r=0.358; P=0.000, P=0.000, and P=0.004). Correlation analysis also showed that DC, |AC|, and SDNN were negatively correlated with NIHSS scores (r=-0.279, r=-0.266, and r=-0.319; P=0.027, P=0.035, and P=0.011). Both DC and AC of heart rate decreased in patients with hemispheric infarction, reflecting a decrease in both vagal and sympathetic modulation. Both DC and AC were correlated with the severity of stroke.
1993-09-30
history of deep vein thrombosis, cerebral embolus, stroke , congestive heart failure, or ischemic heart disease will not be eligible. No concurrent...Jabbari B Seizures , and Parkinsonism. Neurology 43(4): 836-38, 1993. I Mullin JC Localizing Right Septal Accessory Pathways Using the Maximally Pre...Encephalomyopathy, Lactic Acidosis, Stroke -like I Chuang S, Merante F, Episodes (MELAS): Clinical, Radiological, Pathological, and Genetic Robinson BH
Cardiac and Vascular Function in Bedrested Volunteers: Effects of Artificial Gravity Training
NASA Technical Reports Server (NTRS)
Meng, M.; Platts, S.; Stenger, M.; Diedrich, A.; Schlegel, T.; Natapoff, A.; Knapp, C.; Evans, J.
2007-01-01
Cardiovascular effects of an artificial gravity (AG) countermeasure on deconditioned male volunteers were studied. In two groups of men we measured cardiovascular parameters at rest and in response to 30 minutes of 80 deg. head up tilt (HUT) before, at the end of, and four days following 21 days of 6 deg. head down bed rest (HDBR). One group (N=7) underwent no countermeasure while the other (N=8) received a daily, one hour, dose (2.5 gz at the foot, decreasing to 1.0 gz at the heart) of AG training on the Johnson Space Center short radius centrifuge. Cardiovascular parameters measured included heart rate, blood pressure, stroke volume, cardiac output, peripheral vascular resistance, plasma volume shifts, and vasoactive hormones. Untrained subjects exhibited shorter tilt survival (on average 8 minutes shorter) compared to trained subjects. By the end of bed rest, mean heart rate (MHR) was elevated in both groups (both supine and during tilt). In addition, treated subjects demonstrated lower, tilt-induced, increases in MHR four days following HDBR, indicating a more rapid return to pre bed rest conditions. Results from an index of autonomic balance (percentage of MHR spectral power in the respiratory frequency range) in control of heart rate are consistent with the interpretation that parasympathetic nervous system withdrawal was responsible for both tilt- and bed rest-induced increases in MHR. Our data support our pre-study hypothesis that AG treatment would lessen cardiovascular effects of deconditioning in bed rested men and suggest that AG should be further pursued as a space flight countermeasure.
NASA Technical Reports Server (NTRS)
Nandi, P. S.; Spodick, D. H.
1977-01-01
The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.
Cardiovascular Conditions of Childhood
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Medications Used to Treat Heart Failure
... and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you learn about conditions, treatments and procedures related to heart disease and stroke. Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...
Risks for Heart Valve Problems
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Wan, Ruiqian; Ahmet, Ismayil; Brown, Martin; Cheng, Aiwu; Kamimura, Naomi; Talan, Mark; Mattson, Mark P.
2009-01-01
It has been reported that dietary energy restriction, including intermittent fasting (IF), can protect heart and brain cells against injury and improve functional outcome in animal models of myocardial infarction and stroke. Here we report that IF improves glycemic control and protects the myocardium against ischemia-induced cell damage and inflammation in rats. Echocardiographic analysis of heart structural and functional variables revealed that IF attenuates the growth-related increase in posterior ventricular wall thickness, , end systolic and diastolic volumes, and reduces the ejection fraction. The size of the ischemic infarct 24 hours following permanent ligation of a coronary artery was significantly smaller, and markers of inflammation (infiltration of leukocytes in the area at risk and plasma IL-6 levels) were less, in IF rats compared to rats on the control diet. IF resulted in increased levels of circulating adiponectin prior to and after myocardial infarction. Because recent studies have shown that adiponectin can protect the heart against ischemic injury, our findings suggest a potential role for adiponectin as a mediator of the cardioprotective effect of IF. PMID:19423320
Aerobic Stimulus Induced by Virtual Reality Games in Stroke Survivors.
Silva de Sousa, Julio Cesar; Torriani-Pasin, Camila; Tosi, Amanda Barboza; Fecchio, Rafael Yokoyama; Costa, Luiz Augusto Riani; Forjaz, Cláudia Lúcia de Moraes
2018-05-01
To evaluate whether virtual reality games (VRGs) in stroke survivors produce significant and reproducible heart rate and oxygen consumption (V˙o 2 ) responses during their execution, corresponding to an intensity between the anaerobic threshold (AT) and the respiratory compensation point (RCP). Single-subject, repeated-measure design. Stroke survivors registered from a rehabilitation program. Chronic hemiparetic stroke survivors (N=12; 10 men; mean age ± SD, 58±12y) rated at 3 or 4 in the Functional Ambulation Categories. Participants underwent, in a random order, 2 identical sessions of VRGs (console Xbox 360 + Kinect) and 1 control session (38min watching a movie). The VRG sessions were composed of 4 sets of VRGs (3min of tennis, 1min for changing the game, and 4min of boxing) interspaced with 2 minutes of rest. Heart rate and V˙o 2 were measured during the experimental sessions and compared with heart rate and V˙o 2 obtained at AT and RCP assessed during a maximal cardiopulmonary exercise test. Heart rate and V˙o 2 during VRGs had good reproducibility (intraclass correlation coefficients, ≥.91 and ≥.85, respectively; coefficients of variation, ≤6.7% and ≤13.7%, respectively). Heart rate during VRGs was similar to AT and significantly lower than RCP (P≤.05), while V˙o 2 was significantly lower than AT and RCP (P<.05). An acute session of VRGs composed of tennis and boxing games using the console XBox 360 + Kinect promotes reproducible responses of heart rate and V˙o 2 that corresponded, respectively, to AT and below AT, characterizing a low-intensity aerobic stimulus. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Hu, Gwo-Chi; Hsu, Chia-Yu; Yu, Hui-Kung; Chen, Jiann-Perng; Chang, Yu-Ju; Chien, Kuo-Liong
2014-02-01
To investigate the relationship between the volume of inpatient rehabilitation therapy and mortality among patients with acute ischemic stroke, as well as to assess whether the association varies with respect to stroke severity. A retrospective study with a cohort of consecutive patients who had acute ischemic stroke between January 1, 2008, and June 30, 2009. Referral medical center. Adults with acute ischemic stroke (N=1277) who were admitted to a tertiary hospital. Not applicable. Stroke-related mortality. During the median follow-up period of 12.3 months (ranging from January 1, 2008, to December 31, 2009), 163 deaths occurred. Greater volume of rehabilitation therapy was associated with a reduced risk of all-cause and cardiovascular mortality (P for trend <.001 for both). Compared with the first tertile, the third tertile of rehabilitation volume was associated with a 55% lower risk of all-cause mortality (hazard ratio [HR]=.45; 95% confidence interval [CI], .30-.65) and a 50% lower risk of cardiovascular mortality (HR=.50; 95% CI, .31-.82). The association did not vary with respect to stroke severity (P for interaction = .45 and .73 for all-cause and cardiovascular mortality, respectively). The volume of inpatient rehabilitation therapy and mortality were significantly inversely related in the patients with ischemic stroke. Thus, further programs aimed at promoting greater use of rehabilitation services are warranted. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Zefirov, T L; Ziyatdinova, N I; Gainullin, A A; Zefirov, A L
2002-05-01
Experiments on rats showed that blockade of hyperpolarization-activated currents moderates tachycardia induced by beta-adrenoceptor agonist isoproterenol and potentiates the increase in stroke volume produced by this agonist. Electrical stimulation of the vagus nerve against the background of isoproterenol treatment augmented bradycardia and increased stroke volume. Blockade of hyperpolarization-activated currents followed by application of isoproterenol moderated vagus-induced bradycardia and had no effect on the dynamics of stroke volume.
Shen, W F; Roubin, G S; Fletcher, P J; Choong, C Y; Hutton, B F; Harris, P J; Kelly, D T
1985-02-01
The effects of upright and supine position on cardiac response to exercise were assessed by radionuclide ventriculography in 15 patients with moderate to severe aortic regurgitation (AR) and in 10 control subjects. In patients with AR, heart rate was higher during upright exercise, but systolic and diastolic blood pressure and left ventricular (LV) output were similar during both forms of exercise. LV stroke volume and end-diastolic volume were not altered during supine exercise. LV end-systolic volume increased and ejection fraction decreased during supine exercise, but both were unchanged during upright exercise. Of 15 patients, 5 in the upright and 12 in the supine position had an abnormal LV ejection fraction response to exercise (p less than 0.01). Right ventricular ejection fraction increased and regurgitant index decreased with both forms of exercise and was not significantly different between the 2 positions. Thus, posture is important in determining LV response to exercise in patients with moderate to severe AR.
Contribution of Established Stroke Risk Factors to the Burden of Stroke in Young Adults.
Aigner, Annette; Grittner, Ulrike; Rolfs, Arndt; Norrving, Bo; Siegerink, Bob; Busch, Markus A
2017-07-01
As stroke in young adults is assumed to have different etiologies and risk factors than in older populations, the aim of this study was to examine the contribution of established potentially modifiable cardiovascular risk factors to the burden of stroke in young adults. A German nationwide case-control study based on patients enrolled in the SIFAP1 study (Stroke In Young Fabry Patients) 2007 to 2010 and controls from the population-based GEDA study (German Health Update) 2009 to 2010 was performed. Cases were 2125 consecutive patients aged 18 to 55 years with acute first-ever stroke from 26 clinical stroke centers; controls (age- and sex-matched, n=8500, without previous stroke) were from a nationwide community sample. Adjusted population-attributable risks of 8 risk factors (hypertension, hyperlipidemia, diabetes mellitus, coronary heart disease, smoking, heavy episodic alcohol consumption, low physical activity, and obesity) and their combinations for all stroke, ischemic stroke, and primary intracerebral hemorrhage were calculated. Low physical activity and hypertension were the most important risk factors, accounting for 59.7% (95% confidence interval, 56.3-63.2) and 27.1% (95% confidence interval, 23.6-30.6) of all strokes, respectively. All 8 risk factors combined explained 78.9% (95% confidence interval, 76.3-81.4) of all strokes. Population-attributable risks of all risk factors were similar for all ischemic stroke subtypes. Population-attributable risks of most risk factors were higher in older age groups and in men. Modifiable risk factors previously established in older populations also account for a large part of stroke in younger adults, with 4 risk factors explaining almost 80% of stroke risk. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00414583. © 2017 American Heart Association, Inc.
Carroll, John D; Vemulapalli, Sreekanth; Dai, Dadi; Matsouaka, Roland; Blackstone, Eugene; Edwards, Fred; Masoudi, Frederick A; Mack, Michael; Peterson, Eric D; Holmes, David; Rumsfeld, John S; Tuzcu, E Murat; Grover, Frederick
2017-07-04
Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice with efforts to optimize outcomes and minimize the learning curve. The goal of this study was to assess the degree to which increasing experience during the introduction of this procedure, separated from other outcome determinants including patient and procedural characteristics, is associated with outcomes. The authors evaluated the association of hospital TAVR volume and patient outcomes for TAVR by using data from 42,988 commercial procedures conducted at 395 hospitals submitting to the Transcatheter Valve Therapy Registry from 2011 through 2015. Outcomes assessed included adjusted and unadjusted in-hospital major adverse events. Increasing site volume was associated with lower in-hospital risk-adjusted outcomes, including mortality (p < 0.02), vascular complications (p < 0.003), and bleeding (p < 0.001) but was not associated with stroke (p = 0.14). From the first case to the 400th case in the volume-outcome model, risk-adjusted adverse outcomes declined, including mortality (3.57% to 2.15%), bleeding (9.56% to 5.08%), vascular complications (6.11% to 4.20%), and stroke (2.03% to 1.66%). Vascular and bleeding volume-outcome associations were nonlinear with a higher risk of adverse outcomes in the first 100 cases. An association of procedure volume with risk-adjusted outcomes was also seen in the subgroup having transfemoral access. The initial adoption of TAVR into practice in the United States showed that increasing experience was associated with better outcomes. This association, whether deemed a prolonged learning curve or a manifestation of a volume-outcome relationship, suggested that concentrating experience in higher volume heart valve centers might be a means of improving outcomes. (STS/ACC Transcatheter Valve Therapy Registry [TVT Registry]; NCT01737528). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Kamel, Hooman; Healey, Jeff S.
2017-01-01
Cardiac embolism accounts for an increasing proportion of ischemic strokes, and might multiply several-fold over the next decades. However, research points to several potential strategies to stem this expected rise in cardioembolic stroke. First, although one-third of strokes are of unclear cause, it is increasingly accepted that many of these cryptogenic strokes arise from a distant embolism rather than in-situ cerebrovascular disease, leading to the recent formulation of “embolic stroke of undetermined source” (ESUS) as a distinct target for investigation. Second, recent clinical trials have indicated that ESUS may often stem from subclinical atrial fibrillation (AF) which can be diagnosed with prolonged heart-rhythm monitoring. Third, emerging evidence indicates that a thrombogenic atrial substrate can lead to atrial thromboembolism even in the absence of AF. Such an atrial cardiopathy may explain many cases of ESUS, and oral anticoagulant drugs may prove to reduce stroke risk from atrial cardiopathy given its parallels to AF. Non-vitamin K antagonist oral anticoagulant (NOAC) drugs have recently expanded therapeutic options for preventing cardioembolic stroke and are currently being tested for stroke prevention in patients with ESUS, including specifically those with atrial cardiopathy. Fourth, increasing appreciation of thrombogenic atrial substrate and the common co-existence of cardiac and extra-cardiac stroke risk factors suggests benefits from global vascular risk factor management in addition to anticoagulation. Finally, improved imaging of ventricular thrombus plus the availability of NOAC drugs may lead to better prevention of stroke from acute myocardial infarction and heart failure. PMID:28154101
Busingye, Doreen; Pedigo, Ashley; Odoi, Agricola
2011-12-01
The objective of this study was to investigate temporal changes in geographic access to emergency heart attack and stroke care. Network analysis was used to compute travel time to the nearest emergency room (ER), cardiac, and stroke centers in Middle Tennessee. Populations within 30, 60, and 90 min driving time to the nearest ER, cardiac and stroke centers were identified. There were improvements in timely access to cardiac and stroke centers over the study period (1999-2010). There were significant (p<0.0001) increases in the proportion of the population with access to cardiac centers within 30 min from 29.4% (1999) to 62.4% (2009) while that for stroke changed from 5.4% (2004) to 46.1% (2010). Most (96%) of the population had access to an ER within 30 min from 1999 to 2010. Access to care has improved in the last decade but more still needs to be done to address disparities in rural communities. Copyright © 2011 Elsevier Ltd. All rights reserved.
Heart Disease and Stroke Statistics
... or cases are combined. The incidence of a cardiovascular disease in the United States is estimated by multiplying ... accurate data available for assessing the impact of cardiovascular diseases and stroke. These data are compiled from death ...
Neuroimaging Identifies Patients Most Likely to Respond to a Restorative Stroke Therapy.
Cassidy, Jessica M; Tran, George; Quinlan, Erin B; Cramer, Steven C
2018-02-01
Patient heterogeneity reduces statistical power in clinical trials of restorative therapies. Valid predictors of treatment responsiveness are needed, and several have been studied with a focus on corticospinal tract (CST) injury. We studied performance of 4 such measures for predicting behavioral gains in response to motor training therapy. Patients with subacute-chronic hemiparetic stroke (n=47) received standardized arm motor therapy, and change in arm Fugl-Meyer score was calculated from baseline to 1 month post-therapy. Injury measures calculated from baseline magnetic resonance imaging included (1) percent CST overlap with stroke, (2) CST-related atrophy (cerebral peduncle area), (3) CST integrity (fractional anisotropy) in the cerebral peduncle, and (4) CST integrity in the posterior limb of internal capsule. Percent CST overlap with stroke, CST-related atrophy, and CST integrity did not correlate with one another, indicating that these 3 measures captured independent features of CST injury. Percent injury to CST significantly predicted treatment-related behavioral gains ( r =-0.41; P =0.004). The other CST injury measures did not, neither did total infarct volume nor baseline behavioral deficits. When directly comparing patients with mild versus severe injury using the percent CST injury measure, the odds ratio was 15.0 (95% confidence interval, 1.54-147; P <0.005) for deriving clinically important treatment-related gains. Percent CST injury is useful for predicting motor gains in response to therapy in the setting of subacute-chronic stroke. This measure can be used as an entry criterion or a stratifying variable in restorative stroke trials to increase statistical power, reduce sample size, and reduce the cost of such trials. © 2018 American Heart Association, Inc.
Human Cardiovascular Adaptation to Weightlessness
NASA Technical Reports Server (NTRS)
Norsk, Peter
2011-01-01
Entering weightlessness (0 G) induces immediately a shift of blood and fluid from the lower to the upper parts of the body inducing expansion of the cardiac chambers (Bungo et al. 1986; Charles & Lathers 1991; Videbaek & Norsk 1997). For many years the effects of sudden 0 G on central venous pressure (CVP) was discussed, and it puzzled researchers that CVP compared to the 1-G supine position decreased during the initial hours of spaceflight, when at the same time left atrial diameter increased (Buckey et al. 1996). By measuring esophageal pressure as an estimate of inter-pleural pressure, it was later shown that this pressure decreases more than CVP does during 0 G induced by parabolic flights (Videbaek & Norsk 1997). Thus, transmural CVP is increased, which distends the cardiac chambers. This unique lung-heart interaction whereby 1) inter-pleural pressure decreases and 2) central blood volume is expanded is unique for 0 G. Because transmural CVP is increased, stroke volume increases according to the law of Frank-Starling leading to an increase in cardiac output, which is maintained increased during months of 0 G in space to levels of some 25% above that of the 1-G seated position (Norsk unpublished). Simultaneously, sympathetic nervous activity is at the level of the upright 1-G posture, which is difficult to explain based on the high stroke volume and decreased blood pressure and systemic vascular resistance. This paradox should be explored and the mechanisms revealed, because it might have implications for estimating the cardiovascular risk of travelling in space.
Preiss, David; Giles, Thomas D; Thomas, Laine E; Sun, Jie-Lena; Haffner, Steven M; Holman, Rury R; Standl, Eberhard; Mazzone, Theodore; Rutten, Guy E; Tognoni, Gianni; Chiang, Fu-Tien; McMurray, John J V; Califf, Robert M
2013-09-01
Risk factors for stroke are well-established in general populations but sparsely studied in individuals with impaired glucose tolerance. We identified predictors of stroke among participants with impaired glucose tolerance in the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial. Cox proportional-hazard regression models were constructed using baseline variables, including the 2 medications studied, valsartan and nateglinide. Among 9306 participants, 237 experienced a stroke over 6.4 years. Predictors of stroke included classical risk factors such as existing cerebrovascular and coronary heart disease, higher pulse pressure, higher low-density lipoprotein cholesterol, older age, and atrial fibrillation. Other factors, including previous venous thromboembolism, higher waist circumference, lower estimated glomerular filtration rate, lower heart rate, and lower body mass index, provided additional important predictive information, yielding a C-index of 0.72. Glycemic measures were not predictive of stroke. Variables associated with stroke were similar in participants with no prior history of cerebrovascular disease at baseline. The most powerful predictors of stroke in patients with impaired glucose tolerance included a combination of established risk factors and novel variables, such as previous venous thromboembolism and elevated waist circumference, allowing moderately effective identification of high-risk individuals.
Zhang, Dongfeng; Wang, Weijing; Li, Fang
2016-10-18
Resting heart rate is linked to risk of coronary artery disease, stroke, sudden death and noncardiovascular diseases. We conducted a meta-analysis to assess these associations in general populations and in populations of patients with hypertension or diabetes mellitus. We searched PubMed, Embase and MEDLINE from inception to Mar. 5, 2016. We used a random-effects model to combine study-specific relative risks (RRs). We used restricted cubic splines to assess the dose-response relation. We included 45 nonrandomized prospective cohort studies in the meta-analysis. The multivariable adjusted RR with an increment of 10 beats/min in resting heart rate was 1.12 (95% confidence interval [CI] 1.09-1.14) for coronary artery disease, 1.05 (95% CI 1.01-1.08) for stroke, 1.12 (95% CI 1.02-1.24) for sudden death, 1.16 (95% CI 1.12-1.21) for noncardiovascular diseases, 1.09 (95% CI 1.06-1.12) for all types of cancer and 1.25 (95% CI 1.17-1.34) for noncardiovascular diseases excluding cancer. All of these relations were linear. In an analysis by category of resting heart rate (< 60 [reference], 60-70, 70-80 and > 80 beats/min), the RRs were 0.99 (95% CI 0.93-1.04), 1.08 (95% CI 1.01-1.16) and 1.30 (95% CI 1.19-1.43), respectively, for coronary artery disease; 1.08 (95% CI 0.98-1.19), 1.11 (95% CI 0.98-1.25) and 1.08 (95% CI 0.93-1.25), respectively, for stroke; and 1.17 (95% CI 0.94-1.46), 1.31 (95% CI 1.12-1.54) and 1.57 (95% CI 1.39-1.77), respectively, for noncardiovascular diseases. After excluding studies involving patients with hypertension or diabetes, we obtained similar results for coronary artery disease, stroke and noncardiovascular diseases, but found no association with sudden death. Resting heart rate was an independent predictor of coronary artery disease, stroke, sudden death and noncardiovascular diseases over all of the studies combined. When the analysis included only studies concerning general populations, resting heart rate was not associated with sudden death. © 2016 Canadian Medical Association or its licensors.
Gill, Sudeep S; Bronskill, Susan E; Paterson, J Michael; Whitehead, Marlo
2012-01-01
Objective To assess the risk of systemic adverse events associated with intravitreal injections of vascular endothelial growth factor inhibiting drugs. Design Population based nested case-control study. Setting Ontario, Canada. Participants 91 378 older adults with a history of physician diagnosed retinal disease identified between 1 April 2006 and 31 March 2011. Cases were 1477 patients admitted to hospital for ischaemic stroke, 2229 admitted for an acute myocardial infarction, 1059 admitted or assessed in an emergency department for venous thromboembolism, and 2623 admitted for congestive heart failure. Event-free controls (at a ratio of 5:1) were matched to cases on the basis of year of birth, sex, history of the outcome in the previous 5 years, and diabetes. Main exposure measure Exposure to vascular endothelial growth factor inhibiting drugs identified within 180 days before the index date. Results After adjustment for potential confounders, participants who had ischaemic stroke, acute myocardial infarction, congestive heart failure, or venous thromboembolism were not more likely than control participants to have been exposed to either bevacizumab (adjusted odds ratios of 0.95 (95% confidence interval 0.68 to 1.34) for ischaemic stroke, 1.04 (0.77 to 1.39) for acute myocardial infarction, 0.81 (0.49 to 1.34) for venous thromboembolism, and 1.21 (0.91 to 1.62) for congestive heart failure) or ranibizumab (adjusted odds ratios 0.87 (0.68 to 1.10) for ischaemic stroke, 0.90 (0.72 to 1.11) for acute myocardial infarction, 0.88 (0.67 to 1.16) for venous thromboembolism, and 0.87 (0.70 to 1.07) for congestive heart failure). Similarly, a secondary analysis of exclusive users of bevacizumab or ranibizumab showed no differences in risk between the two drugs (adjusted odds ratios for bevacizumab relative to ranibizumab of 1.03 (0.67 to 1.60) for ischaemic stroke, 1.23 (0.85 to 1.77) for acute myocardial infarction, 0.92 (0.51 to 1.69) for venous thromboembolism, and 1.35 (0.93 to 1.95) for congestive heart failure). These findings were consistent for all but one outcome in subgroup analyses. Conclusions Intravitreal injections of bevacizumab and ranibizumab were not associated with significant risks of ischaemic stroke, acute myocardial infarction, congestive heart failure, or venous thromboembolism. PMID:22763393
Recognizing Advanced Heart Failure and Knowing Your Options
... and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you learn about conditions, treatments and procedures related to heart disease and stroke. Popular Articles 1 Understanding Blood Pressure Readings 2 Sodium and Salt 3 Heart Attack Symptoms ...
Gong, Jie; Chen, Xinguang; Li, Sijian
2015-01-01
Objective To evaluate the efficacy of the program Keep Moving toward Healthy Heart and Healthy Brain (KM2H2) in encouraging physical activities for the prevention of heart attack and stroke among hypertensive patients enrolled in the Community-Based Hypertension Control Program (CBHCP). Design Cluster randomized controlled trial with three waves of longitudinal assessments at baseline, 3 and 6 months post intervention. Setting Community-based and patient-centered self-care for behavioral intervention in urban settings of China. Participants A total of 450 participants diagnosed with hypertension from 12 community health centers in Wuhan, China were recruited, and were randomly assigned by center to receive either KM2H2 plus standard CBHCP care (6 centers and 232 patients) or the standard care only (6 centers and 218 patients). Intervention KM2H2 is a behavioral intervention guided by the Transtheoretical Model, the Model of Personalized Medicine and Social Capital Theory. It consists of six intervention sessions and two booster sessions engineered in a progressive manner. The purpose is to motivate and maintain physical activities for the prevention of heart attack and stroke. Outcome Measures Heart attack and stroke (clinically diagnosed, primary outcome), blood pressure (measured, secondary outcome), and physical activity (self-report, tertiary outcome) were assessed at the individual level during the baseline, 3- and 6-month post-intervention. Results Relative to the standard care, receiving KM2H2 was associated with significant reductions in the incidence of heart attack (3.60% vs. 7.03%, p < .05) and stroke (5.11% vs. 9.90%, p<0.05), and moderate reduction in blood pressure (-3.72mmHg in DBP and -2.92 mmHg in DBP) at 6-month post-intervention; and significant increases in physical activity at 3- (d = 0.53, 95% CI: 0.21, 0.85) and 6-month (d = 0.45, 95% CI: 0.04, 0.85) post-intervention, respectively. Conclusion The program KM2H2 is efficacious to reduce the risk of heart attack and stroke among senior patients who are on anti-hypertensive medication. Findings of this study provide solid data supporting a formal phase-III trial to establish the effectiveness of KM2H2 for use in community settings for prevention. Trial Registration ISRCTN Register ISRCTN12608966 PMID:26426421
Modrall, J Gregory; Chung, Jayer; Kirkwood, Melissa L; Baig, M Shadman; Tsai, Shirling X; Timaran, Carlos H; Valentine, R James; Rosero, Eric B
2014-07-01
Prior studies have demonstrated improved clinical outcomes for surgeons with a high-volume experience with certain open vascular operations. A high-volume experience with carotid artery stenting (CAS) improves clinical outcomes. Moreover, it is not known whether experience with other endovascular procedures, including percutaneous coronary interventions (PCIs), is an adequate substitute for experience with CAS. The goal of this study was to quantify the effect of increasing clinician volume of CAS, endovascular aneurysm repair (EVAR), and thoracic endovascular aortic aneurysm repair (TEVAR), and PCI on the outcomes for CAS. The Nationwide Inpatient Sample was analyzed to identify patients undergoing CAS for the years 2005 to 2009. Clinicians were stratified into tertiles of low-volume, medium-volume, and high-volume groups by annual volume of CAS, EVAR/TEVAR, and PCI. Multiple logistic regression analyses were used to examine the relationship between clinician volume and a composite outcome of the in-hospital stroke and death rate after CAS. Between 2005 and 2009, 56,374 elective CAS procedures were performed nationwide, with a crude in-hospital stroke and death rate of 3.22%. A median of nine CAS procedures (interquartile range, 3-20) were performed annually per clinician. As expected, stroke and death rates for CAS decreased with increasing volume of CAS performed by a clinician (low-volume vs medium-volume vs high-volume: 4.43% vs 2.89% vs 2.27%; P = .0001). Similar patterns were noted between clinicians' volume of EVAR/TEVAR (low-volume vs medium-volume vs high-volume: 4.58% vs 3.18% vs 2.16%; P = .0023). In contrast, increasing PCI volume was not associated with decreased stroke and death rates after CAS (low-volume vs medium-volume vs high-volume: 2.99% vs 3.18% vs 3.55%; P = .35). After adjusting for patient and hospital characteristics, clinician volume of CAS (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.74-0.94; P = .003) and EVAR/TEVAR (OR, 0.85; 95% CI, 0.75-0.97; P = .020) remained significant predictors of stroke and death after CAS, whereas increasing clinician volume of PCI was associated with significantly increasing likelihood of stroke or death after CAS (OR, 1.025; 95% CI, 1.004-1.047; P = .019). The stroke and death rate for CAS to treat carotid stenosis is inversely affected by the number of CAS and EVAR/TEVAR procedures performed by a clinician. In contrast, a high-volume experience with PCI is not associated with improved outcomes after CAS. Copyright © 2014 Society for Vascular Surgery. All rights reserved.
Mortality After Pediatric Arterial Ischemic Stroke.
Beslow, Lauren A; Dowling, Michael M; Hassanein, Sahar M A; Lynch, John K; Zafeiriou, Dimitrios; Sun, Lisa R; Kopyta, Ilona; Titomanlio, Luigi; Kolk, Anneli; Chan, Anthony; Biller, Jose; Grabowski, Eric F; Abdalla, Abdalla A; Mackay, Mark T; deVeber, Gabrielle
2018-05-01
Cerebrovascular disease is among the top 10 causes of death in US children, but risk factors for mortality are poorly understood. Within an international registry, we identify predictors of in-hospital mortality after pediatric arterial ischemic stroke (AIS). Neonates (0-28 days) and children (29 days-<19 years) with AIS were enrolled from January 2003 to July 2014 in a multinational stroke registry. Death during hospitalization and cause of death were ascertained from medical records. Logistic regression was used to analyze associations between risk factors and in-hospital mortality. Fourteen of 915 neonates (1.5%) and 70 of 2273 children (3.1%) died during hospitalization. Of 48 cases with reported causes of death, 31 (64.6%) were stroke-related, with remaining deaths attributed to medical disease. In multivariable analysis, congenital heart disease (odds ratio [OR]: 3.88; 95% confidence interval [CI]: 1.23-12.29; P = .021), posterior plus anterior circulation stroke (OR: 5.36; 95% CI: 1.70-16.85; P = .004), and stroke presentation without seizures (OR: 3.95; 95% CI: 1.26-12.37; P = .019) were associated with in-hospital mortality for neonates. Hispanic ethnicity (OR: 3.12; 95% CI: 1.56-6.24; P = .001), congenital heart disease (OR: 3.14; 95% CI: 1.75-5.61; P < .001), and posterior plus anterior circulation stroke (OR: 2.71; 95% CI: 1.40-5.25; P = .003) were associated with in-hospital mortality for children. In-hospital mortality occurred in 2.6% of pediatric AIS cases. Most deaths were attributable to stroke. Risk factors for in-hospital mortality included congenital heart disease and posterior plus anterior circulation stroke. Presentation without seizures and Hispanic ethnicity were also associated with mortality for neonates and children, respectively. Awareness and study of risk factors for mortality represent opportunities to increase survival. Copyright © 2018 by the American Academy of Pediatrics.
Bodapati, Rohan K; Kizer, Jorge R; Kop, Willem J; Kamel, Hooman; Stein, Phyllis K
2017-07-21
Heart rate variability (HRV) characterizes cardiac autonomic functioning. The association of HRV with stroke is uncertain. We examined whether 24-hour HRV added predictive value to the Cardiovascular Health Study clinical stroke risk score (CHS-SCORE), previously developed at the baseline examination. N=884 stroke-free CHS participants (age 75.3±4.6), with 24-hour Holters adequate for HRV analysis at the 1994-1995 examination, had 68 strokes over ≤8 year follow-up (median 7.3 [interquartile range 7.1-7.6] years). The value of adding HRV to the CHS-SCORE was assessed with stepwise Cox regression analysis. The CHS-SCORE predicted incident stroke (HR=1.06 per unit increment, P =0.005). Two HRV parameters, decreased coefficient of variance of NN intervals (CV%, P =0.031) and decreased power law slope (SLOPE, P =0.033) also entered the model, but these did not significantly improve the c-statistic ( P =0.47). In a secondary analysis, dichotomization of CV% (LOWCV% ≤12.8%) was found to maximally stratify higher-risk participants after adjustment for CHS-SCORE. Similarly, dichotomizing SLOPE (LOWSLOPE <-1.4) maximally stratified higher-risk participants. When these HRV categories were combined (eg, HIGHCV% with HIGHSLOPE), the c-statistic for the model with the CHS-SCORE and combined HRV categories was 0.68, significantly higher than 0.61 for the CHS-SCORE alone ( P =0.02). In this sample of older adults, 2 HRV parameters, CV% and power law slope, emerged as significantly associated with incident stroke when added to a validated clinical risk score. After each parameter was dichotomized based on its optimal cut point in this sample, their composite significantly improved prediction of incident stroke during ≤8-year follow-up. These findings will require validation in separate, larger cohorts. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.
Shams, Tanzila; Auchus, Alexander P; Oparil, Suzanne; Wright, Clinton B; Wright, Jackson; Furlan, Anthony J; Sila, Cathy A; Davis, Barry R; Pressel, Sara; Yamal, Jose-Miguel; Einhorn, Paula T; Lerner, Alan J
2017-11-01
The visual analogue scale is a self-reported, validated tool to measure quality of life (QoL). Our purpose was to determine whether baseline QoL predicted strokes in the ALLHAT study (Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial) and evaluate determinants of poststroke change in QoL. In the ALLHAT study, among the 33 357 patients randomized to treatment arms, 1525 experienced strokes; 1202 (79%) strokes were nonfatal. This study cohort includes 32 318 (97%) subjects who completed the baseline visual analogue scale QoL estimate. QoL was measured on a visual analogue scale and adjusted using a Torrance transformation (transformed QoL [TQoL]). Kaplan-Meier curves and adjusted proportional hazards analyses were used to estimate the effect of TQoL on the risk of stroke, on a continuous scale (0-1) and by quartiles (≤0.81, >0.81≤0.89, >0.89≤0.95, >0.95). We analyzed the change from baseline to first poststroke TQoL using adjusted linear regression. After adjusting for multiple stroke risk factors, the hazard ratio for stroke events for baseline TQoL was 0.93 (95% confidence interval, 0.89-0.98) per 0.1 U increase. The lowest baseline TQoL quartile had a 20% increased stroke risk (hazard ratio=1.20 [95% confidence interval, 1.00-1.44]) compared with the reference highest quartile TQoL. Poststroke TQoL change was significant within all treatment groups ( P ≤0.001). Multivariate regression analysis revealed that baseline TQoL was the strongest predictor of poststroke TQoL with similar results for the untransformed QoL. The lowest baseline TQoL quartile had a 20% higher stroke risk than the highest quartile. Baseline TQoL was the only factor that predicted poststroke change in TQoL. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000542. © 2017 American Heart Association, Inc.
Kim, Tae-Hoon; Yang, Pil-Sung; Uhm, Jae-Sun; Kim, Jong-Youn; Pak, Hui-Nam; Lee, Moon-Hyoung; Joung, Boyoung; Lip, Gregory Y H
2017-06-01
The CHA 2 DS 2 -VASc stroke score (congestive heart failure, hypertension, age ≥75 (doubled), diabetes mellitus, prior stroke or transient ischemic attack (doubled), vascular disease, age 65-74, female) is used in most guidelines for risk stratification in atrial fibrillation (AF), but most data for this score have been derived in Western populations. Ethnic differences in stroke risk may be present. Our objective was to investigate risk factors for stroke in AF and application of the CHA 2 DS 2 -VASc score in an Asian AF population from Korea. A total of 5855 oral anticoagulant-naive nonvalvular AF patients aged ≥20 years were enrolled from Korea National Health Insurance Service Sample cohort from 2002 to 2008 and were followed up until December 2013. The incidence rates (per 100 person-years) of ischemic stroke were 3.32 in the total population, being 0.23 in low-risk (CHA 2 DS 2 -VASc score 0 [male] or 1 [female]) and 4.59 in high-risk patients (CHA 2 DS 2 -VASc ≥2). Incidence rates of ischemic stroke or the composite thromboembolism end point showed a clear increase with increasing CHA 2 DS 2 -VASc score. On multivariable analysis, significant associations between CHA 2 DS 2 -VASc risk factors and ischemic stroke were observed; however, the significance of vascular disease or diabetes mellitus was attenuated after multivariate adjustment, and female sex (hazard ratio, 0.73; 95% confidence interval, 0.64-0.84) had a lower risk of ischemic stroke than males. Patients who were categorized as low risk consistently had an event rate <1% per year. The performance of CHA 2 DS 2 -VASc score in Asians is comparable with that in Western populations. The score shows good performance in defining the truly-low-risk AF patients for stroke/thromboembolism. © 2017 American Heart Association, Inc.
Improvement on the auxiliary total artificial heart (ATAH) left chamber design.
Andrade, Aron; Fonseca, Jeison; Legendre, Daniel; Nicolosi, Denys; Biscegli, Jose; Pinotti, Marcos; Ohashi, Yukio; Nosé, Yukihiko
2003-05-01
The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow. The ATAH left and right stroke volumes are 38 ml and 34 ml, respectively, giving approximately 5 L/min of cardiac output at 160 bpm. Flow visualization studies were performed in critical areas on the ATAH left chamber. A closed circuit loop was used with water and glycerin (37%) at 25 degrees C. Amberlite particles (80 mesh) were illuminated by a 1 mm planar helium-neon laser light. With left mean preload fixed at 10 mm Hg and the afterload at 100 mm Hg, the heart rate varied from 60 to 200 bpm. Two porcine valves were used on the inlet and outlet ports. The flow pattern images were obtained using a color micro-camera and a video recorder. Subsequently, these images were digitized using a PC computer. A persistent stagnant flow was detected in the left chamber inlet port. After improvement on the left chamber design, this stagnant flow disappeared.
Cholesterol testing and results
... profile results; Hyperlipidemia-results; Lipid disorder test results; Heart disease - cholesterol results ... at an earlier age if you have: Diabetes Heart disease Stroke High blood pressure A strong family history ...
Soares, Bruno P; Tong, Elizabeth; Hom, Jason; Cheng, Su-Chun; Bredno, Joerg; Boussel, Loic; Smith, Wade S; Wintermark, Max
2010-01-01
The purpose of this study was to compare recanalization and reperfusion in terms of their predictive value for imaging outcomes (follow-up infarct volume, infarct growth, salvaged penumbra) and clinical outcome in acute ischemic stroke patients. Twenty-two patients admitted within 6 hours of stroke onset were retrospectively included in this study. These patients underwent a first stroke CT protocol including CT-angiography (CTA) and perfusion-CT (PCT) on admission, and similar imaging after treatment, typically around 24 hours, to assess recanalization and reperfusion. Recanalization was assessed by comparing arterial patency on admission and posttreatment CTAs; reperfusion, by comparing the volumes of CBV, CBF, and MTT abnormality on admission and posttreatment PCTs. Collateral flow was graded on the admission CTA. Follow-up infarct volume was measured on the discharge noncontrast CT. The groups of patients with reperfusion, no reperfusion, recanalization, and no recanalization were compared in terms of imaging and clinical outcomes. Reperfusion (using an MTT reperfusion index >75%) was a more accurate predictor of follow-up infarct volume than recanalization. Collateral flow and recanalization were not accurate predictors of follow-up infarct volume. An interaction term was found between reperfusion and the volume of the admission penumbra >50 mL. Our study provides evidence that reperfusion is a more accurate predictor of follow-up infarct volume in acute ischemic stroke patients than recanalization. We recommend an MTT reperfusion index >75% to assess therapy efficacy in future acute ischemic stroke trials that use perfusion-CT.
Boshuizen, Hendriek C; Lanti, Mariapaola; Menotti, Alessandro; Moschandreas, Joanna; Tolonen, Hanna; Nissinen, Aulikki; Nedeljkovic, Srecko; Kafatos, Anthony; Kromhout, Daan
2007-02-15
The authors aimed to quantify the effects of current systolic blood pressure (SBP) and serum total cholesterol on the risk of mortality in comparison with SBP or serum cholesterol 25 years previously, taking measurement error into account. The authors reanalyzed 35-year follow-up data on mortality due to coronary heart disease and stroke among subjects aged 65 years or more from nine cohorts of the Seven Countries Study. The two-step method of Tsiatis et al. (J Am Stat Assoc 1995;90:27-37) was used to adjust for regression dilution bias, and results were compared with those obtained using more commonly applied methods of adjustment for regression dilution bias. It was found that the commonly used univariate adjustment for regression dilution bias overestimates the effects of both SBP and cholesterol compared with multivariate methods. Also, the two-step method makes better use of the information available, resulting in smaller confidence intervals. Results comparing recent and past exposure indicated that past SBP is more important than recent SBP in terms of its effect on coronary heart disease mortality, while both recent and past values seem to be important for effects of cholesterol on coronary heart disease mortality and effects of SBP on stroke mortality. Associations between serum cholesterol concentration and risk of stroke mortality are weak.
Premature ventricular complexes on screening electrocardiogram and risk of ischemic stroke.
Agarwal, Sunil K; Chao, Jennifer; Peace, Frederick; Judd, Suzanne E; Kissela, Brett; Kleindorfer, Dawn; Howard, Virginia J; Howard, George; Soliman, Elsayed Z
2015-05-01
Premature ventricular complexes (PVCs) detected from long-term ECG recordings have been associated with an increased risk of ischemic stroke. Whether PVCs seen on routine ECG, commonly used in clinical practice, are associated with an increased risk of ischemic stroke remains unstudied. This analysis included 24 460 participants (aged, 64.5+9.3 years; 55.1% women; 40.0% blacks) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who were free of stroke at the time of enrollment. PVCs were ascertained from baseline ECG (2003-2007), and incident stroke cases through 2011 were confirmed by an adjudication committee. A total of 1415 (5.8%) participants had at least 1 PVC at baseline, and 591 developed incident ischemic stroke during an average (SD) follow-up of 6.0 (2.0) years. In a cox proportional hazards model adjusted for age, sex, race, geographic region, education, previous heart disease, systolic blood pressure, blood pressure-lowering medications, current smoking, diabetes mellitus, left ventricular hypertrophy by ECG, and aspirin use and warfarin use, the presence of PVCs was associated with 38% increased risk of ischemic stroke (hazard ratio [95% confidence interval], 1.38 [1.05-1.81]). PVCs are common on routine screening ECGs and are associated with an increased risk of ischemic stroke. © 2015 American Heart Association, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hurwitz, R.A.; Treves, S.; Freed, M.
The ability to quantitate aortic (AR) or mitral regurgitation (MR), or both, by radionuclide angiocardiography was evaluated in children and young adults at rest and during isometric exercise. Regurgitation was estimated by determining the ratio of left ventricular stroke volume to right ventricular stroke volume obtained during equilibrium ventriculography. The radionuclide measurement was compared with results of cineangiography, with good correlation between both studies in 47 of 48 patients. Radionuclide stroke volume ratio was used to classify severity: the group with equivocal regurgitation differed from the group with mild regurgitation (p less than 0.02); patients with mild regurgitation differed frommore » those with moderate regurgitation (p less than 0.001); and those with moderate regurgitation differed from those with severe regurgitation (p less than 0.01). The stroke volume ratio was responsive to isometric exercise, remaining constant or increasing in 16 of 18 patients. After surgery to correct regurgitation, the stroke volume ratio significantly decreased from preoperative measurements in all 7 patients evaluated. Results from the present study demonstrate that a stroke volume ratio greater than 2.0 is compatible with moderately severe regurgitation and that a ratio greater than 3.0 suggests the presence of severe regurgitation. Thus, radionuclide angiocardiography should be useful for noninvasive quantitation of AR or MR, or both, helping define the course of young patients with left-side valvular regurgitation.« less
Li, Chao-jin-zi; Du, Xiao-xia; Yang, Kun; Song, Lu-ping; Li, Peng-kun; Wang, Qiang; Sun, Rong; Lin, Xiao-ling; Lu, Hong-yu; Zhang, Tong
2016-01-01
Young stroke patients have a strong desire to return to the society, but few studies have been conducted on their rehabilitation training items, intensity, and prognosis. We analyzed clinical data of young and middle-aged/older stroke patients hospitalized in the Department of Neurological Rehabilitation, China Rehabilitation Research Center, Capital Medical University, China from February 2014 to May 2015. Results demonstrated that hemorrhagic stroke (59.6%) was the primary stroke type found in the young group, while ischemic stroke (60.0%) was the main type detected in the middle-aged/older group. Compared with older stroke patients, education level and incidence of hyperhomocysteinemia were higher in younger stroke patients, whereas, incidences of hypertension, diabetes, and heart disease were lower. The average length of hospital stay was longer in the young group than in the middle-aged/older group. The main risk factors observed in the young stroke patients were hypertension, drinking, smoking, hyperlipidemia, hyperhomocysteinemia, diabetes, previous history of stroke, and heart disease. The most accepted rehabilitation program consisted of physiotherapy, occupational therapy, speech therapy, acupuncture and moxibustion. Average rehabilitation training time was 2.5 hours/day. Barthel Index and modified Rankin Scale scores were increased at discharge. Six months after discharge, the degree of occupational and economic satisfaction declined, and there were no changes in family life satisfaction. The degrees of other life satisfaction (such as friendship) improved. The degree of disability and functional status improved significantly in young stroke patients after professional rehabilitation, but the number of patients who returned to society within 6 months after stroke was still small. PMID:28123417
Stefanidou, Maria; Das, Rohit R; Beiser, Alexa S; Sundar, Banu; Kelly-Hayes, Margaret; Kase, Carlos S; Devinsky, Orrin; Seshadri, Sudha; Friedman, Daniel
2017-04-01
We examined the incidence of seizures following ischemic stroke in a community-based sample. All subjects with incident ischemic strokes in the Framingham Original and Offspring cohorts between 1982 and 2003 were identified and followed for up to 20 years to determine incidence of seizures. Seizure-type was based on the 2010 International League Against Epilepsy (ILAE) classification. Disability was stratified into mild/none, moderate and severe, based on post-stroke neurological deficit documentation according to the Framingham Heart Study (FHS) protocol and functional status was determined using the Barthel Index. An initial ischemic stroke occurred in 469 subjects in the cohort and seizures occurred in 25 (5.3%) of these subjects. Seizure incidence was similar in both large artery atherosclerosis (LAA) (6.8%) and cardio-embolic (CE) (6.2%) strokes. No seizures occurred following lacunar strokes. The predominant seizure type was focal seizure with or without evolution to bilateral convulsive seizure. One third of participants had seizures within the first 24h from stroke onset and half of all seizures occurred within the first 30days. On multivariate analysis, moderate and severe disability following stroke was associated with increased risk of incident seizure. Seizures occurred in approximately 5% of subjects after an ischemic stroke. One third of these seizures occurred in the first 24h after stroke and none followed lacunar strokes. Focal seizures with or without evolution in bilateral convulsive seizures were the most common seizure type. Moderate and severe disability was predictive of incident seizures. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
Murata, Makoto; Adachi, Hitoshi; Oshima, Shigeru; Kurabayashi, Masahiko
2017-01-01
In a given individual, a consistent relationship exists between oxygen uptake (V˙O 2 ) and heart rate (HR) during exercise. The quotient of V˙O 2 and HR (V˙O 2 /HR) is called the oxygen pulse (O 2 pulse), and its value is dependent on stroke volume (SV). However, it is difficult to believe that the O 2 pulse would indicate the SV when HR has been modified as with the use of beta-adrenergic receptor blockers (BB). Until now, the effect of BB on peak O 2 pulse has not been precisely studied. We tried to clarify the effect of BB on the relationship between O 2 pulse and SV. Of 699 consecutive heart disease subjects who performed cardiopulmonary exercise tests (CPX) from 2012 to 2014, we enrolled 430 subjects who had sinus rhythm and could perform CPX until exhaustion. One hundred and fifty-seven subjects were taking BB. SV was evaluated during CPX using impedance cardiography, and we compared the peak O 2 pulse with peak SV between patients without BB (Group A) and with BB (Group B). The HRs at rest and peak exercise in Group A were greater than those in Group B (74.4±13.0/min vs. 71.8±11.3/min, p<0.01, 134.9±21.7/min vs. 124.9±23.6/min, p<0.01, respectively). The regression line of the peak O 2 pulse against the peak SV was steeper in Group B than in Group A. When we divided the patients into two groups according to the average values of the peak SV and peak V˙O 2 , O 2 pulse/SV ratio in Group B above the average was greater than that in Group A, whereas it was similar in the two groups that were below average. We found that the increase in the O 2 pulse was disproportionately greater than the SV that was measured by impedance cardiography when a BB was used in patients with preserved SV and exercise tolerance. Copyright © 2016. Published by Elsevier Ltd.
Menêses, Annelise Lins; Forjaz, Cláudia Lúcia de Moraes; de Lima, Paulo Fernando Marinho; Batista, Rafael Marinho Falcão; Monteiro, Maria de Fátima; Ritti-Dias, Raphael Mendes
2015-03-01
The study aims to evaluate the effects of the order of endurance and resistance exercises on postexercise blood pressure (BP) and hemodynamics in hypertensive women. Nineteen hypertensive women underwent 3 sessions: control (50 minutes rest), endurance (50-60% of heart rate reserve) followed by resistance exercise (50% of 1 repetition maximum) (E + R), and resistance followed by endurance exercise (R + E). Before and 30 minutes after each session, BP, peripheral vascular resistance, cardiac output, stroke volume, and heart rate were measured. Postexercise increases in systolic (E + R: +1 ± 3 mm Hg and R + E: +3 ± 3 mm Hg), diastolic (E + R: +3 ± 1 mm Hg and R + E: +3 ± 2 mm Hg), and mean BP (E + R: +3 ± 1 mm Hg and R + E: +3 ± 2 mm Hg) were significantly lower after the exercise sessions compared with the control session (p ≤ 0.05). The exercise sessions abolished the increases in peripheral vascular resistance (E + R: +0.00 ± 0.04 mm Hg·min·L and R + E: +0.05 ± 0.05 mm Hg·min·L) and the decreases in cardiac output (E + R: +0.04 ± 0.28 L·min and R + E: -0.26 ± 0.28 L·min) observed after the control session (p ≤ 0.05). After the exercise sessions, stroke volume decreased (E + R: -14 ± 3 ml and R + E: -9 ± 4 ml) and heart rate increased (E + R: +5 ± 1 b·min and R + E: +4 ± 1 b·min) in comparison with the control session (p ≤ 0.05). For all the variables, there were no significant differences between the exercise sessions. Regardless of the order of endurance and resistance exercises, combined exercise sessions abolished increases in BP observed in a control condition due to a reduction in peripheral vascular resistance and increases in cardiac output. Thus, combined exercises should be prescribed to individuals with hypertension to control their BP, regardless of the order they are accomplished.
Atrial Fibrillation: Complications
... of this page please turn JavaScript on. Feature: Atrial Fibrillation Atrial Fibrillation: Complications Past Issues / Winter 2015 Table of Contents ... has two major complications—stroke and heart failure. Atrial Fibrillation and Stroke Click to enlarge image This illustration ...
Decline in Cardiovascular Mortality: Possible Causes and Implications.
Mensah, George A; Wei, Gina S; Sorlie, Paul D; Fine, Lawrence J; Rosenberg, Yves; Kaufmann, Peter G; Mussolino, Michael E; Hsu, Lucy L; Addou, Ebyan; Engelgau, Michael M; Gordon, David
2017-01-20
If the control of infectious diseases was the public health success story of the first half of the 20th century, then the decline in mortality from coronary heart disease and stroke has been the success story of the century's past 4 decades. The early phase of this decline in coronary heart disease and stroke was unexpected and controversial when first reported in the mid-1970s, having followed 60 years of gradual increase as the US population aged. However, in 1978, the participants in a conference convened by the National Heart, Lung, and Blood Institute concluded that a significant recent downtick in coronary heart disease and stroke mortality rates had definitely occurred, at least in the US Since 1978, a sharp decline in mortality rates from coronary heart disease and stroke has become unmistakable throughout the industrialized world, with age-adjusted mortality rates having declined to about one third of their 1960s baseline by 2000. Models have shown that this remarkable decline has been fueled by rapid progress in both prevention and treatment, including precipitous declines in cigarette smoking, improvements in hypertension treatment and control, widespread use of statins to lower circulating cholesterol levels, and the development and timely use of thrombolysis and stents in acute coronary syndrome to limit or prevent infarction. However, despite the huge growth in knowledge and advances in prevention and treatment, there remain many questions about this decline. In fact, there is evidence that the rate of decline may have abated and may even be showing early signs of reversal in some population groups. The National Heart, Lung, and Blood Institute, through a request for information, is soliciting input that could inform a follow-up conference on or near the 40th anniversary of the original landmark conference to further explore these trends in cardiovascular mortality in the context of what has come before and what may lie ahead. © 2017 American Heart Association, Inc.
Did we misunderstand how to calculate total stroke work in mitral regurgitation by echocardiography?
Shingu, Yasushige; Matsui, Yoshiro
2012-01-01
Total stroke work (TSW) is used for the estimation of cardiac efficiency in mitral regurgitation (MR). We should be cautious about the interpretation of this parameter, especially when it is assessed by non-invasive methods such as echocardiography. For the calculation of regurgitant stroke work, regurgitant volume is usually multiplied by left atrial (LA) pressure. However, by considering the left ventricular (LV) pressure-volume loop, it would be more appropriate to multiply regurgitant volume and the LV pressure, not the atrial one. We might underestimate TSW when we use LA pressure for the estimation of regurgitant stroke work.
... of heart surgery) that may involve inserting coronary stents (metal tubes surgically placed in clogged blood vessels ... heart attack or stroke. If you have a stent, there is also a higher risk that you ...
"Keep the Beat" Healthy Blood Pressure Helps Prevent Heart Disease | NIH MedlinePlus the Magazine
... Keep the Beat": Healthy Blood Pressure Helps Prevent Heart Disease Past Issues / Winter 2010 Table of Contents Your ... a condition that also increases the chance of heart disease and stroke. High blood pressure is especially common ...
Traylor, Matthew; Adib-Samii, Poneh; Thijs, Vincent; Sudlow, Cathie; Rothwell, Peter M.; Boncoraglio, Giorgio; Dichgans, Martin; Meschia, James; Maguire, Jane; Levi, Christopher; Rost, Natalia S.; Rosand, Jonathan; Hassan, Ahamad; Bevan, Steve; Markus, Hugh S.
2016-01-01
Background and Purpose— Elevated plasma homocysteine levels are associated with stroke. However, this might be a reflection of bias or confounding because trials have failed to demonstrate an effect from homocysteine lowering in stroke patients, although a possible benefit has been suggested in lacunar stroke. Genetic studies could potentially overcome these issues because genetic variants are inherited randomly and are fixed at conception. Therefore, we tested the homocysteine levels–associated genetic variant MTHFR C677T for association with magnetic resonance imaging–confirmed lacunar stroke and compared this with associations with large artery and cardioembolic stroke subtypes. Methods— We included 1359 magnetic resonance imaging–confirmed lacunar stroke cases, 1824 large artery stroke cases, 1970 cardioembolic stroke cases, and 14 448 controls, all of European ancestry. Furthermore, we studied 3670 ischemic stroke patients in whom white matter hyperintensities volume was measured. We tested MTHFR C677T for association with stroke subtypes and white matter hyperintensities volume. Because of the established association of homocysteine with hypertension, we additionally stratified for hypertension status. Results— MTHFR C677T was associated with lacunar stroke (P=0.0003) and white matter hyperintensity volume (P=0.04), but not with the other stroke subtypes. Stratifying the lacunar stroke cases for hypertension status confirmed this association in hypertensive individuals (P=0.0002), but not in normotensive individuals (P=0.30). Conclusions— MTHFR C677T was associated with magnetic resonance imaging–confirmed lacunar stroke, but not large artery or cardioembolic stroke. The association may act through increased susceptibility to, or interaction with, high blood pressure. This heterogeneity of association might explain the lack of effect of lowering homocysteine in secondary prevention trials which included all strokes. PMID:26839351
Hemphill, J Claude; Greenberg, Steven M; Anderson, Craig S; Becker, Kyra; Bendok, Bernard R; Cushman, Mary; Fung, Gordon L; Goldstein, Joshua N; Macdonald, R Loch; Mitchell, Pamela H; Scott, Phillip A; Selim, Magdy H; Woo, Daniel
2015-07-01
The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of spontaneous intracerebral hemorrhage. A formal literature search of PubMed was performed through the end of August 2013. The writing committee met by teleconference to discuss narrative text and recommendations. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Oversight Committee and Stroke Council Leadership Committee. Evidence-based guidelines are presented for the care of patients with acute intracerebral hemorrhage. Topics focused on diagnosis, management of coagulopathy and blood pressure, prevention and control of secondary brain injury and intracranial pressure, the role of surgery, outcome prediction, rehabilitation, secondary prevention, and future considerations. Results of new phase 3 trials were incorporated. Intracerebral hemorrhage remains a serious condition for which early aggressive care is warranted. These guidelines provide a framework for goal-directed treatment of the patient with intracerebral hemorrhage. © 2015 American Heart Association, Inc.
Blood Volume: Its Adaptation to Endurance Training
NASA Technical Reports Server (NTRS)
Convertino, Victor A.
1991-01-01
Expansion of blood volume (hypervolemia) has been well documented in both cross-sectional and longitudinal studies as a consequence of endurance exercise training. Plasma volume expansion can account for nearly all of the exercise-induced hypervolemia up to 2-4 wk; after this time expansion may be distributed equally between plasma and red cell volumes. The exercise stimulus for hypervolemia has both thermal and nonthermal components that increase total circulating plasma levels of electrolytes and proteins. Although protein and fluid shifts from the extravascular to intravascular space may provide a mechanism for rapid hypervolemia immediately after exercise, evidence supports the notion that chronic hypervolemia associated with exercise training represents a net expansion of total body water and solutes. This net increase of body fluids with exercise training is associated with increased water intake and decreased urine volume output. The mechanism of reduced urine output appears to be increased renal tubular reabsorption of sodium through a more sensitive aldosterone action in man. Exercise training-induced hypervolemia appears to be universal among most animal species, although the mechanisms may be quite different. The hypervolemia may provide advantages of greater body fluid for heat dissipation and thermoregulatory stability as well as larger vascular volume and filling pressure for greater cardiac stroke volume and lower heart rates during exercise.
Age at Natural Menopause and Risk of Ischemic Stroke: The Framingham Heart Study
Lisabeth, Lynda D; Beiser, Alexa S; Brown, Devin L; Murabito, Joanne M; Kelly-Hayes, Margaret; Wolf, Philip A
2009-01-01
Background Women have increased lifetime stroke risk and more disabling strokes compared with men. Insights into the association between menopause and stroke could lead to new prevention strategies for women. The objective of this study was to examine the association of age at natural menopause with ischemic stroke risk in the Framingham Heart Study. Methods Participants included women who survived stroke-free until age 60, experienced natural menopause, did not use estrogen prior to menopause, and who had complete data (n=1,430). Participants were followed until first ischemic stroke, death, or end of follow-up (2006). Age at natural menopause was self-reported. Cox proportional hazards models were used to examine the association between age at natural menopause (<42, 42-54, ≥55) and ischemic stroke risk adjusted for age, systolic blood pressure, atrial fibrillation, diabetes, current smoking, cardiovascular disease and estrogen use. Results There were 234 ischemic strokes identified. Average age at menopause was 49 years (sd=4). Women with menopause at ages 42-54 (HR=0.50; 95% CI:0.29-0.89) and at ages ≥55 (HR=0.31; 95% CI:0.13-0.76) had lower stroke risk compared with those with menopause <42 years adjusted for covariates. Women with menopause before age 42 had twice the stroke risk compared to all other women (HR=2.03; 95% CI: 1.16-3.56). Conclusion In this prospective study, age at natural menopause before age 42 was associated with increased ischemic stroke risk. Future stroke studies with measures of endogenous hormones are needed to inform the underlying mechanisms so that novel prevention strategies for mid-life women can be considered. PMID:19233935
Ashouri, Hazar; Orlandic, Lara; Inan, Omer T.
2016-01-01
Unobtrusive and inexpensive technologies for monitoring the cardiovascular health of heart failure (HF) patients outside the clinic can potentially improve their continuity of care by enabling therapies to be adjusted dynamically based on the changing needs of the patients. Specifically, cardiac contractility and stroke volume (SV) are two key aspects of cardiovascular health that change significantly for HF patients as their condition worsens, yet these parameters are typically measured only in hospital/clinical settings, or with implantable sensors. In this work, we demonstrate accurate measurement of cardiac contractility (based on pre-ejection period, PEP, timings) and SV changes in subjects using ballistocardiogram (BCG) signals detected via a high bandwidth force plate. The measurement is unobtrusive, as it simply requires the subject to stand still on the force plate while holding electrodes in the hands for simultaneous electrocardiogram (ECG) detection. Specifically, we aimed to assess whether the high bandwidth force plate can provide accuracy beyond what is achieved using modified weighing scales we have developed in prior studies, based on timing intervals, as well as signal-to-noise ratio (SNR) estimates. Our results indicate that the force plate BCG measurement provides more accurate timing information and allows for better estimation of PEP than the scale BCG (r2 = 0.85 vs. r2 = 0.81) during resting conditions. This correlation is stronger during recovery after exercise due to more significant changes in PEP (r2 = 0.92). The improvement in accuracy can be attributed to the wider bandwidth of the force plate. ∆SV (i.e., changes in stroke volume) estimations from the force plate BCG resulted in an average error percentage of 5.3% with a standard deviation of ±4.2% across all subjects. Finally, SNR calculations showed slightly better SNR in the force plate measurements among all subjects but the small difference confirmed that SNR is limited by motion artifacts rather than instrumentation. PMID:27240380
Hemodynamic and neurohormonal responses to extreme orthostatic stress in physically fit young adults
NASA Astrophysics Data System (ADS)
Grasser, E. K.; Goswami, N.; Rössler, A.; Vrecko, K.; Hinghofer-Szalkay, H.
2009-04-01
Blood pressure stability may be jeopardized in astronauts experiencing orthostatic stress. There is disagreement about cardiovascular and endocrine stress responses that emerge when a critical (presyncopal) state is reached. We studied hemodynamic and neurohormonal changes as induced by an orthostatic stress paradigm (head-up tilt combined with lower body negative pressure) that leads to a syncopal endpoint. From supine control to presyncope, heart rate increased by 78% and thoracic impedance by 12%. There was a 49% fall in stroke volume index, 19% in mean arterial blood pressure, 14% in total peripheral resistance index and 11% in plasma volume. Plasma norepinephrine rose by 107, epinephrine by 491, plasma renin activity by 167, and cortisol by 25%. Hemodynamic and hormonal changes of clearly different magnitude emerge in presyncope as compared to supine rest. Additional studies are warranted to reveal the exact time course of orthostatic changes up to syncopal levels.