Use of the Frank-Starling mechanism during exercise is linked to exercise-induced 130912s in arterial load.

MedStar author(s):
Citation: American Journal of Physiology - Heart & Circulatory Physiology. 302(1):H349-58, 2012 Jan 1.PMID: 22003052Institution: MedStar Heart & Vascular InstituteForm of publication: Journal ArticleMedline article type(s): Journal Article | Research Support, N.I.H., Extramural | Research Support, N.I.H., Intramural | Research Support, Non-U.S. Gov'tSubject headings: *Exercise/ph [Physiology] | *Hemodynamics | *Models, Cardiovascular | *Muscle Contraction | *Muscle, Skeletal/bs [Blood Supply] | Adult | Aged | Analysis of Variance | Arteries/ph [Physiology] | Baltimore | Blood Pressure | Cardiac Output | Compliance | Exercise Test | Female | Heart Rate | Humans | Longitudinal Studies | Male | Middle Aged | Stroke Volume | Time Factors | Vascular Resistance | Ventricular Function, LeftLocal holdings: Available online through MWHC library: 2008-2010ISSN:
  • 0363-6135
Name of journal: American journal of physiology. Heart and circulatory physiologyAbstract: Effective arterial elastance(E(A)) is a measure of the net arterial load imposed on the heart that integrates the effects of heart rate(HR), peripheral vascular resistance(PVR), and total arterial compliance(TAC) and is a modulator of cardiac performance. To what extent the 130912 in E(A) during exercise impacts on cardiac performance and aerobic capacity is unknown. We examined E(A) and its relationship with cardiovascular performance in 352 healthy subjects. Subjects underwent rest and exercise gated scans to measure cardiac volumes and to derive E(A)[end-systolic pressure/stroke volume index(SV)], PVR[MAP/(SV*HR)], and TAC(SV/pulse pressure). E(A) varied with exercise intensity: the E(A) between rest and peak exercise along with its determinants, differed among individuals and ranged from -44% to +149%, and was independent of age and sex. Individuals were separated into 3 groups based on their E(A)I. Individuals with the largest increase in E(A)(group 3;E(A)>=0.98 mmHg.m(2)/ml) had the smallest reduction in PVR, the greatest reduction in TAC and a similar increase in HR vs. group 1(E(A)<0.22 mmHg.m(2)/ml). Furthermore, group 3 had a reduction in end-diastolic volume, and a blunted increase in SV(80%), and cardiac output(27%), during exercise vs. group 1. Despite limitations in the Frank-Starling mechanism and cardiac function, peak aerobic capacity did not differ by group because arterial-venous oxygen difference was greater in group 3 vs. 1. Thus the 130912 in arterial load during exercise has important effects on the Frank-Starling mechanism and cardiac performance but not on exercise capacity. These findings provide interesting insights into the dynamic cardiovascular alterations during exercise.All authors: Becker LC, Chantler PD, Ferrucci L, Fleg JL, Gerstenblith G, Lakatta EG, Melenovsky V, Najjar SS, Schulman SPDigital Object Identifier: Date added to catalog: 2013-09-17
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Journal Article MedStar Authors Catalog Article Available 22003052

Available online through MWHC library: 2008-2010

Effective arterial elastance(E(A)) is a measure of the net arterial load imposed on the heart that integrates the effects of heart rate(HR), peripheral vascular resistance(PVR), and total arterial compliance(TAC) and is a modulator of cardiac performance. To what extent the 130912 in E(A) during exercise impacts on cardiac performance and aerobic capacity is unknown. We examined E(A) and its relationship with cardiovascular performance in 352 healthy subjects. Subjects underwent rest and exercise gated scans to measure cardiac volumes and to derive E(A)[end-systolic pressure/stroke volume index(SV)], PVR[MAP/(SV*HR)], and TAC(SV/pulse pressure). E(A) varied with exercise intensity: the E(A) between rest and peak exercise along with its determinants, differed among individuals and ranged from -44% to +149%, and was independent of age and sex. Individuals were separated into 3 groups based on their E(A)I. Individuals with the largest increase in E(A)(group 3;E(A)>=0.98 mmHg.m(2)/ml) had the smallest reduction in PVR, the greatest reduction in TAC and a similar increase in HR vs. group 1(E(A)<0.22 mmHg.m(2)/ml). Furthermore, group 3 had a reduction in end-diastolic volume, and a blunted increase in SV(80%), and cardiac output(27%), during exercise vs. group 1. Despite limitations in the Frank-Starling mechanism and cardiac function, peak aerobic capacity did not differ by group because arterial-venous oxygen difference was greater in group 3 vs. 1. Thus the 130912 in arterial load during exercise has important effects on the Frank-Starling mechanism and cardiac performance but not on exercise capacity. These findings provide interesting insights into the dynamic cardiovascular alterations during exercise.

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