Cardiovascular response to dynamic exercise in patients with chronic symptomatic mild-to-moderate and severe aortic regurgitation.

Abstract

Fifteen patients with symptomatic mild-to-moderate and severe chronic aortic regurgitation (AR) performed supine bicycle exercise while measurements of rest (1) in patients with mild-to-moderate AR, the PAWP is generally normal at rest and exercise, (2) in most of those with severe AR, the PAWP is elevated at rest and increases significantly with exercise, which is the likely mechanism for dyspnea on exertion in these patients, (3) the cardiac index in both groups is normal at rest and increases on exercise, (4) the increase in cardiac output results from both an increased heart rate and forward stroke volume, (5) the increase in forward stroke volume results from reductions of RgV and RgF, (6) the RgV and RgF are decreased due to a decreased SVR, and (7) the ejection fraction response to exercise is variable and correlates best with changes in SVR with exercise.

ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease

“…In 1 study (275), the LV ejection fraction during exercise was an independent risk factor. However, the direction and magnitude of change in ejection fraction from rest to exercise is related not only to myocardial contractility (279) but also to severity of volume overload (271,278 -280) and exercise-induced changes in preload and peripheral resistance (280). In 2 multivariate analyses (271,276), only age and end-systolic dimension on initial study were independent predictors of outcome, as were the rate of increase in end-systolic dimension and decrease in resting ejection fraction during serial longitudinal studies (271).…”

2008 Focused Update Incorporated Into the ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease

“…However, the direction and magnitude of change in ejection fraction from rest to exercise is related not only to myocardial contractility 279 but also to severity of volume overload 271,278 -280 and exerciseinduced changes in preload and peripheral resistance. 280 In 2 multivariate analyses, 271,276 only age and end-systolic dimension on initial study were independent predictors of outcome, as were the rate of increase in end-systolic dimension and decrease in resting ejection fraction during serial longitudinal studies. 271 During a mean follow-up period of 8 years, patients with initial end-systolic dimensions greater than 50 mm had a likelihood of death, symptoms, and/or LV dysfunction of 19% per year.…”

“…The ejection fraction response to exercise has not proved to have independent prognostic value in patients undergoing surgery. 254 The change in ejection fraction with exercise is a relatively nonspecific response related to both severity of volume load 271,296,300,301 and exercise-induced changes in preload and peripheral resistance 280 that develop early in the natural history of AR. AVR should also not be recommended in asymptomatic patients with normal systolic function merely because of evidence of LV dilatation as long as the dilatation is not severe (end-diastolic dimension less than 75 mm or endsystolic dimension less than 55 mm).…”

ACC/AHA 2006 Guidelines for the Management of Patients With Valvular Heart Disease

“…In 1 study (275), the LV ejection fraction during exercise was an independent risk factor. However, the direction and magnitude of change in ejection fraction from rest to exercise is related not only to myocardial contractility (279) but also to severity of volume overload (271,278 -280) and exercise-induced changes in preload and peripheral resistance (280). In 2 multivariate analyses (271,276), only age and end-systolic dimension on initial study were independent predictors of outcome, as were the rate of increase in end-systolic dimension and decrease in resting ejection fraction during serial longitudinal studies (271).…”