Key role of left ventricular untwisting in endurance cyclists at onset of exercise

2021 ◽  
Author(s):  
Omar Izem ◽  
Laurent Mourot ◽  
Nicolas Tordi ◽  
Antoine Grandperrin ◽  
Philippe Obert ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Speckle Tracking Echocardiography ◽  
Young Male ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Filling Rate ◽  
Ventricular Filling Pressure ◽  
Basal Rotation ◽  
Ventricular Filling

The rise in oxygen consumption during the transition from rest to exercise is faster in those who are endurance-trained than those who have sedentary lifestyles, partly due to a more efficient cardiac response. However, data regarding this acute cardiac response in trained individuals are limited to heart rate (HR), stroke volume and cardiac output. Considering this, we compared cardiac kinetics, including left ventricular (LV) strains and twist/untwist mechanics, between endurance-trained cyclists and their sedentary counterparts. Twenty young, male, trained cyclists and 23 untrained participants aged 18-25 years performed five similar constant workload exercises on a cyclo-ergometer (target HR: 130 bpm). During each session, LV myocardial diastolic and systolic linear strains, as well as torsional mechanics, were assessed using speckle-tracking echocardiography. Cardiac function was evaluated every 15s during the first minute and every 30s thereafter, until 240s. Stroke volume increased during the first 30-45s in both groups, but to a significantly greater extent in trained cyclists (31% vs 24%). Systolic parameters were similar in both groups. Transmitral peak filling velocity and peak filling rate responded faster to exercise and with greater amplitude in trained cyclists. Left ventricular filling pressure was lower in the former, while LV relaxation was greater, but only at the base of the left ventricle. Basal rotation and peak untwisting rate responded faster and to a greater extent in the cyclists. This study provides new mechanical insights into the key role of LV untwisting in the more efficient acute cardiac response of endurance-trained athletes at onset of exercise.

scholarly journals Pathogenetic treatment of chronic heart failure: the role of torasemide

2015 ◽  
Vol 12 (3) ◽  
pp. 56-62
Author(s):  
N B Perepech
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Diastolic Dysfunction ◽  
Clinical Studies ◽  
Clinical Manifestations ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Ventricular Filling Pressure ◽  
Ventricular Filling

The article discusses the torasemide pharmacokinetic characteristics which are favourably different from furosemide characteristics. We paid attention to the fact that torasemide had anti-aldosteronic and antifibrotic effects; all these characteristics were alien to other diuretics nature. The results of clinical studies showed torasemide ability to prevent the development and reverse myocardial fibrosis. Taking into account modern representations concerning the pathogenesis of chronic heart failure, in particular the role of diastolic dysfunction in developing haemodynamic compromise, we substantiated torasemide application as a part of complex pharmacotherapy of chronic heart failure in patients with elevated left ventricular filling pressure before the appearance of clinical manifestations of stagnation.

scholarly journals Time courses of central hemodynamics during rapid changes in posture

2014 ◽  
Vol 116 (9) ◽  
pp. 1182-1188 ◽  
Author(s):  
Patrik Sundblad ◽  
Jonas Spaak ◽  
Lennart Kaijser
Keyword(s):  
Left Ventricle ◽  
Stroke Volume ◽  
Pressure Difference ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Ventricular Filling Pressure ◽  
Leg Exercise ◽  
Time Courses ◽  
The Right ◽  
Ventricular Filling

Changes in posture cause blood volume redistribution, affecting cardiac filling and stroke volume (SV). We hypothesized that the time courses of ventricular filling would differ between the right and left ventricle during a rapid (2 s) tilt and that changes in right ventricular filling pressure would be more swift because of the direct coupling to the systemic circulation. We further hypothesized that the transient imbalance between right and left ventricular filling pressure would influence left ventricular SV changes. Right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), left ventricular stroke volume, heart rate, and arterial pressure were recorded beat-by-beat during rapid tilts from supine to upright positions and back again, during rest and dynamic 100-W leg exercise. RAP changes had a faster time course than PCWP during down-tilts, both during rest and exercise (1 ± 1 vs. 6 ± 2 s and 2 ± 2 vs. 6 ± 2 s, respectively; P < 0.05). This discrepancy caused a transient decrease in the end-diastolic pressure difference between the right and left ventricle. The decreased pressure difference in diastole impeded left ventricular filling because of ventricular interdependence, causing SV to fall transiently. The mechanisms of ventricular interdependence were also involved in reverse during up-tilt, where SV was maintained for 2–3 s despite falling PCWP. Furthermore, the decrease in RAP during up-tilt in the resting condition was biphasic with an initial fast and a second slower component, which might suggest the effect of venous valves. This was not seen during dynamic leg exercise where blood pooling is prevented by the venous muscle pump.

Impaired left ventricular filling due to right-to-left ventricular interaction in patients with pulmonary arterial hypertension

2006 ◽  
Vol 290 (4) ◽  
pp. H1528-H1533 ◽  
Author(s):  
C. Tji-Joong Gan ◽  
Jan-Willem Lankhaar ◽  
J. Tim Marcus ◽  
Nico Westerhof ◽  
Koen M. Marques ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Left Atrial ◽  
Interventricular Septum ◽  
Left Ventricular ◽  
Left Ventricular Filling ◽  
Filling Rate ◽  
End Diastolic Volume ◽  
Ventricular Interaction ◽  
Pulmonary Arterial ◽  
Ventricular Filling

The aim of this study was to investigate the contribution of direct right-to-left ventricular interaction to left ventricular filling and stroke volume in 46 patients with pulmonary arterial hypertension (PAH) and 18 control subjects. Stroke volume, right and left ventricular volumes, left ventricular filling rate, and interventricular septum curvature were measured by magnetic resonance imaging and left atrial filling by transesophageal echocardiography. Stroke volume, left ventricular end-diastolic volume, and left ventricular peak filling rate were decreased in PAH patients compared with control subjects: 28 ± 13 vs. 41 ± 10 ml/m2( P < 0.001), 46 ± 14 vs. 61 ± 14 ml/m2( P < 0.001), and 216 ± 90 vs. 541 ± 248 ml/s ( P < 0.001), respectively. Among PAH patients, stroke volume did not correlate to right ventricular end-diastolic volume or mean pulmonary arterial pressure but did correlate to left ventricular end-diastolic volume ( r = 0.62, P < 0.001). Leftward interventricular septum curvature was correlated to left ventricular filling rate ( r = 0.64, P < 0.001) and left ventricular end-diastolic volume ( r = 0.65, P < 0.001). In contrast, left atrial filling was normal and not correlated to left ventricular end-diastolic volume. In PAH patients, ventricular interaction mediated by the interventricular septum impairs left ventricular filling, contributing to decreased stroke volume.

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