Article
Computer Science, Information Systems
Mohanad Alkhodari, Herbert F. Jelinek, Shiza Saleem, Leontios J. Hadjileontiadis, Ahsan H. Khandoker
Summary: This study aimed to investigate the ability of heart rate variability (HRV) in categorizing CAD patients into multiple LVEF groups, based on optimizing indices extracted from HRV data to form HFpEF, HFmEF, and HFrEF categories. The findings showed that HRVEF groups exhibited consistent patterns throughout the diurnal cycle, with various HRV indices playing significant roles in differentiating between HRVEF groups at different time periods.
Article
Neurosciences
Junichiro Hayano, Norihiro Ueda, Masaya Kisohara, Emi Yuda, Robert M. Carney, James A. Blumenthal
Summary: In post-AMI patients, the risk of mortality in patients with low LVEF is mainly predicted by indices reflecting decreased HRV or HR responsiveness and cardiac parasympathetic dysfunction, while in patients without low LVEF, the risk is mainly predicted by a combination of indices reflecting decreased HRV or HR responsiveness and indicator reflecting abrupt large HR changes suggesting sympathetic involvement.
FRONTIERS IN NEUROSCIENCE
(2021)
Review
Cardiac & Cardiovascular Systems
Alia S. Alhakak, John R. Teerlink, Joann Lindenfeld, Michael Boehm, Giuseppe M. C. Rosano, Tor Biering-Sorensen
Summary: LVET is the time interval from aortic valve opening to closure in which the left ventricle ejects blood into the aorta. It has long been used to assess left ventricular function and contractility, but recent interest focuses on its use as a measure of therapeutic action for heart failure patients. This review provides an overview of LVET measurement methods, mechanistic understanding, association with outcomes, mechanisms behind LVET shortening in heart failure, and potential drug implications.
EUROPEAN JOURNAL OF HEART FAILURE
(2021)
Article
Cardiac & Cardiovascular Systems
Rachel J. Skow, Nicole A. Garza, Damsara Nandadeva, Brandi Y. Stephens, Alexis N. Wright, Ann-Katrin Grotle, Benjamin E. Young, Paul J. Fadel
Summary: Emerging evidence suggests that COVID-19 may affect cardiac autonomic function, but the limited findings in young adults have been inconclusive. This study found no significant differences in heart rate variability and cardiac baroreflex sensitivity between young adults with persistent symptoms following COVID-19, those who were asymptomatic, and controls who never had COVID-19. However, there were significant relationships between measures of cardiac autonomic function and time since diagnosis, suggesting that COVID-19-related changes in cardiac autonomic function are transient in young, otherwise healthy adults.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2022)
Article
Clinical Neurology
Bruce D. Nearing, Imad Libbus, Gerrard M. Carlson, Badri Amurthur, Bruce H. KenKnight, Richard L. Verrier
Summary: This study shows that chronic high-intensity vagus nerve stimulation improves intrinsic heart rate recovery, heart rate turbulence slope, and left ventricular ejection fraction over a period of 3 years. The correlated favorable effects on heart rate turbulence slope suggest enhanced baroreceptor function in response to vagus nerve stimulation.
CLINICAL AUTONOMIC RESEARCH
(2021)
Article
Cardiac & Cardiovascular Systems
Sebastian Rosch, Karl-Patrik Kresoja, Christian Besler, Karl Fengler, Anne Rebecca Schoeber, Maximilian von Roeder, Christian Luecke, Matthias Gutberlet, Karin Klingel, Holger Thiele, Karl-Philipp Rommel, Philipp Lurz
Summary: In this study, patients with heart failure with preserved ejection fraction (HFpEF) were stratified based on left ventricular ejection fraction (LVEF), resulting in distinct morphologic and pathophysiologic subphenotypes. Patients with LVEF ranging from 50% to 60% demonstrated reduced contractility, impaired ventriculo-arterial coupling, and higher extracellular volume fraction, while patients with LVEF >60% exhibited a hypercontractile state with excessive left ventricular afterload and diminished preload reserve.
Review
Cardiac & Cardiovascular Systems
Brian P. Halliday, Roxy Senior, Dudley J. Pennell
Summary: The measurement of left ventricular ejection fraction (LVEF) has been a key component in imaging studies for cardiac patients, but its utility as a prognostic indicator has diminished in certain populations such as heart failure patients with preserved ejection fraction (HF-PEF) and those with valvular heart disease. Assessing myocardial strain, particularly global longitudinal strain (GLS), holds promise in improving risk stratification and therapy selection for these patients. Additional studies are needed to fully integrate GLS into routine clinical practice and improve patient outcomes.
EUROPEAN HEART JOURNAL
(2021)
Review
Cardiac & Cardiovascular Systems
Brian P. Halliday, Roxy Senior, Dudley J. Pennell
Summary: Traditional methods of assessing cardiac function like LVEF are no longer accurate in predicting prognosis for heart failure patients, highlighting the need for better indicators such as GLS to improve risk stratification and accuracy of disease assessment. For patients with heart failure and valvular heart disease, GLS may be a superior option to consider.
EUROPEAN HEART JOURNAL
(2021)
Article
Health Care Sciences & Services
Konstantinos Spathoulas, Vasiliki Tsolaki, George E. Zakynthinos, Dimitrios Karelas, Demosthenes Makris, Epaminondas Zakynthinos, John Papanikolaou
Summary: This study suggests that bedside echocardiographic assessment of LVEF, VTI, and their adjustment to corresponding SVR values in ICU provides valuable insights into understanding SC phenotypes, underlying vasoplegia, and cardiac output fluctuations in septic shock.
JOURNAL OF PERSONALIZED MEDICINE
(2022)
Article
Biology
Liliya Poskotinova, Elena Krivonogova, Denis Demin, Tatyana Zenchenko
Summary: This study investigated the synchronization between heart rate variability (HRV) in the low-frequency range and variations in geomagnetic induction in individuals with normal and high blood pressure. The results showed that there was significant synchronization between HRV and geomagnetic induction in individuals with normal blood pressure, indicating a potential risk of dysregulation of vascular tone in individuals with high blood pressure.
Article
Radiology, Nuclear Medicine & Medical Imaging
Shuang Li, Yining Wang, Wenjing Yang, Di Zhou, Baiyan Zhuang, Jing Xu, Jian He, Gang Yin, Xiaohan Fan, Weichun Wu, Piyush Sharma, Arlene Sirajuddin, Andrew E. Arai, Shihua Zhao, Minjie Lu
Summary: This retrospective study aimed to identify clinical and cardiac MRI risk factors for adverse events in patients with dilated cardiomyopathy (DCM) and left ventricular ejection fraction (LVEF) of 35% or higher. The results showed that myocardial scar at late gadolinium enhancement (LGE) MRI equal to or greater than 7.1% of the LV mass was associated with sudden cardiac death (SCD) or aborted SCD.
Article
Medicine, General & Internal
Joshua Saef, Trejeeve Martyn, Anusha Ray Dey, Rola Khedraki, Lauren Ives, Patrick Collier, Wael A. Jaber, Jerry D. Estep, Mazen Hanna, Wai Hong Wilson Tang
Summary: This study reveals that in patients with impaired left ventricular ejection fraction (LVEF) due to ATTR-CM, more than one-third of patients showed improvement in LVEF over time, while those with a decrease in LVEF had worse long-term outcomes.
JOURNAL OF CLINICAL MEDICINE
(2023)
Article
Medicine, General & Internal
Gabriele Pestelli, Valeria Pergola, Giuseppe Totaro, Marco Previtero, Patrizia Aruta, Antonella Cecchetto, Andrea Fiorencis, Chiara Palermo, Sabino Iliceto, Donato Mele
Summary: Correcting LVET can help to assess the severity of aortic stenosis (AS) more accurately, regardless of the hemodynamic conditions.
JOURNAL OF CLINICAL MEDICINE
(2022)
Article
Medicine, General & Internal
Banafsheh Arshi, Sven Geurts, Martijn J. Tilly, Marten van den Berg, Jan A. Kors, Dimitris Rizopoulos, M. Arfan Ikram, Maryam Kavousi
Summary: HRV indices are associated with worse systolic function in men and improvement in left atrial size in women. Higher HRV is associated with a higher risk of new-onset HF in men.
Article
Environmental Sciences
Erica M. Marshall, Jason C. Parks, Emily K. Erb, Stacie M. Humm, J. Derek Kingsley
Summary: This study compared the cardiac autonomic responses following bilateral and unilateral upper-body acute resistance exercise. The results showed that both types of exercise led to decreased heart rate variability and baroreflex sensitivity, which did not recover within 30 minutes.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Neurosciences
Bartek Kulas, Stephen A. Klassen, M. Erin Moir, J. Kevin Shoemaker
Summary: This study examines the effects of baroreceptor unloading and volitional end-expiratory apnea on the firing patterns of sympathetic postganglionic neurons. The results suggest that these factors can modify the discharge rate, recruitment, and latency of sympathetic neurons.
JOURNAL OF NEUROPHYSIOLOGY
(2022)
Article
Neurosciences
Rory A. Marshall, Adam M. S. Luchkanych, Jude S. Morton, Natasha G. Boyes, Alexander Zhai, Darcy D. Marciniuk, Yixue Mei, Elric Y. Allison, J. Kevin Shoemaker, Baraa K. Al-Khazraji, Matti D. Allen, Corey R. Tomczak, T. Dylan Olver
Summary: Ventricular arrhythmias are associated with cerebral hypoperfusion and neurological impairment. This study found that irregular heartbeats, both single and multiple, influence cerebral haemodynamics in a population-specific, arrhythmia-type and organ-dependent manner. The magnitude of these haemodynamic perturbations is greatest in heart failure patients with reduced ejection fraction and is inversely related to cognitive performance. Chronic arrhythmias may exacerbate existing cerebral hypoperfusion in these patients.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Physiology
T. Dylan Olver, Mark B. Badrov, Matti D. Allen, Nicole S. Coverdale, J. Kevin Shoemaker
Summary: The study examines the relationship between muscle sympathetic nerve activity (MSNA), vascular compliance, and peripheral blood flow responses. It reveals that during apnea, increases in MSNA are associated with reductions in vascular compliance and decreased blood flow rate. However, during static handgrip exercise, despite increased MSNA, there is an increase in vascular compliance that is unrelated to blood flow increases.
PHYSIOLOGICAL REPORTS
(2022)
Article
Physiology
Patrick Siedlecki, J. Kevin Shoemaker, Tanya D. Ivanova, S. Jayne Garland
Summary: This study investigated the cardiovascular response and cardiac baroreflex sensitivity to postural perturbations. Results showed that heart rate varied with intensity of perturbations, while systolic blood pressure and cBRS were not intensity-dependent. Additionally, cBRS was elevated post-perturbations compared to baseline, indicating an effect on the stability of the cardiac baroreflex.
PHYSIOLOGICAL REPORTS
(2022)
Article
Physiology
Eric T. Hedge, Richard L. Hughson
Summary: During the COVID-19 pandemic, some young healthy individuals experienced a loss of cardiorespiratory fitness, while others maintained their fitness but gained weight. These changes could potentially increase the risk of adverse health outcomes and disease later in life.
JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Article
Physiology
Andrew W. D'Souza, Stephen A. Klassen, Mark B. Badrov, Sophie Lalande, J. Kevin Shoemaker
Summary: This study found that spontaneous baroreflex control of muscle sympathetic nerve activity and action potential subpopulations is weakened in older adults compared to young adults, while sympathetic transduction is also impaired in older adults. The findings suggest that aging may lead to an enhanced central arc of the baroreflex to compensate for impairments in the peripheral arc.
JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Article
Physiology
Leah M. Mann, Jason S. Chan, Sarah A. Angus, Connor J. Doherty, Benjamin P. Thompson, Glen E. Foster, Richard L. Hughson, Paolo B. Dominelli
Summary: Hypercapnic chemosensitivity is influenced by acute exercise, aerobic fitness, and sex. In this study, we found that higher fitness participants did not necessarily have lower chemosensitivity, but males had a higher chemoresponse compared to females. These findings suggest that sex, unlike aerobic fitness, has an impact on peripheral hypercapnic chemosensitivity.
JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Article
Cardiac & Cardiovascular Systems
M. Erin Moir, Stephen A. Klassen, Mair Zamir, J. W. Hamner, Can Ozan Tan, J. Kevin Shoemaker
Summary: Increasing evidence suggests that cerebrovascular compliance plays a role in regulating cerebral blood flow, but the mechanisms involved in humans are still unknown. This study investigated the impact of neural, endothelial, and myogenic mechanisms on vascular compliance in the cerebral and forearm vascular beds. The results showed that adrenergic, cholinergic, and myogenic mechanisms all contribute to the regulation of vascular compliance, with myogenic mechanisms exerting more specific control in the brain.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2023)
Article
Physiology
Carmelo J. Mastrandrea, Eric T. Hedge, Andrew D. Robertson, George A. Heckman, Joanne Ho, Federico Granados Unger, Richard L. Hughson
Summary: Prolonged bedrest can cause orthostatic hypotension and intolerance of upright posture. This randomized controlled trial investigated if exercise could mitigate orthostatic intolerance in healthy older adults after 14-day head-down bedrest. The results showed that high-intensity interval exercise did not benefit post-HDBR orthostatic tolerance in older adults, and multiple factors were associated with the reduction in cerebral blood velocity leading to intolerance.
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2023)
Article
Physiology
Eric T. Hedge, Robert Amelard, Richard L. Hughson
Summary: Nonintrusive estimation of oxygen uptake (V_O2) is possible with wearable sensor technology and artificial intelligence. This study aimed to test the accuracy of a machine learning model in predicting dynamic V_O2 across exercise intensities, including slower V_O2 kinetics observed during heavy exercise. The results showed that the model accurately predicted V_O2 kinetics and enabled nonintrusive monitoring of cardiorespiratory dynamics during moderate and heavy exercise.
JOURNAL OF APPLIED PHYSIOLOGY
(2023)
Article
Physiology
Richard L. Hughson, Eric T. Hedge, Carmelo J. Mastrandrea
Summary: Cardiorespiratory fitness declines with age and can be accelerated by inactivity and bed rest. The recovery timeline for adults aged 55-65 is unknown, and the effectiveness of exercise during bed rest is unexplored in this age group. A study found that approximately 1 hour of daily exercise protected the cardiorespiratory fitness of adults aged 55-65 during 2 weeks of bed rest.
JOURNAL OF APPLIED PHYSIOLOGY
(2023)
Article
Neurosciences
Stephen A. Klassen, Mark B. Badrov, M. Erin Moir, J. Kevin Shoemaker
Summary: This study found that during fatiguing volitional exercise in humans, descending cortical signals and ascending skeletal muscle metaboreflex signals have divergent control over baroreflex resetting of sympathetic action potential discharge. Both isometric hand-grip exercise and postexercise circulatory occlusion reset baroreflex control of sympathetic action potentials to higher blood pressures. However, only postexercise circulatory occlusion increased the baroreflex gain of medium-sized sympathetic action potentials.
JOURNAL OF NEUROPHYSIOLOGY
(2023)
Article
Neurosciences
Andrew W. D'Souza, Ryosuke Takeda, Kazumasa Manabe, Sarah L. Hissen, Takuro Washio, Geoff B. Coombs, Belinda Sanchez, Qi Fu, J. Kevin Shoemaker
Summary: The impact of age on exercise pressor responses differs between males and females. Older males exhibit larger increases in blood pressure and total peripheral resistance during handgrip exercise compared to younger males. However, age does not have a significant effect on these responses in females. Testosterone levels play a role in the observed sex-specific differences. These findings highlight the importance of considering biological sex when studying age-related changes in neuro-cardiovascular control during exercise.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Endocrinology & Metabolism
Eric T. Hedge, Laurence Vico, Richard L. Hughson, Carmelo J. Mastrandrea
Summary: The hemodynamics of human skeletal remain inadequately studied, particularly the assessment of weight-bearing bones during walking and after periods of immobility. This study investigated the tibial hemodynamics of older adults before and after a period of head-down bed rest. The results showed slower desaturation kinetics in the tibia during walking and faster tHb kinetics upon standing, with altered oxygenated hemoglobin kinetics after bed rest. These findings highlight the need for further investigation into tibial hemodynamics in humans.
Article
Cardiac & Cardiovascular Systems
Andrew W. D'Souza, Sarah L. Hissen, Kazumasa Manabe, Ryosuke Takeda, Takuro Washio, Geoff B. Coombs, Belinda Sanchez, Qi Fu, J. Kevin Shoemaker
Summary: Sympathetic vascular transduction is attenuated in older adults compared to young adults, and there is an inverse relationship between the central and peripheral arcs of the baroreflex. Age and sex have independent and interactive effects on sympathetic vascular transduction and sympathetic neurohemodynamic balance in humans.
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
(2023)