Evaluation of relationship between myocardial contractile state and left ventricular function in patients with aortic regurgitation.

Abstract

We studied the relationship between myocardial contractile state and left ventricular functional response to exercise in 14 asymptomatic patients with isolated moderate-to-severe aortic regurgitation and six control subjects. The slope of the systolic blood pressure-left ventricular endsystolic volume (pressure-volume) relationship determined by radionuclide ventriculography during angiotensin infusion was used as an indirect measure of myocardial contractility and was compared with left ventricular ejection fraction at rest and during both isometric handgrip and dynamic bicycle exercise. The slope of the pressure-volume relationship was significantly lower in patients with aortic regurgitation than in the control subjects (1.75 + 0.57 vs 2.78 + 0.42, p < 0.01). The slope correlated exponentially with resting ejection fraction and was linearly related to changes in left ventricular ejection fraction during both handgrip and bicycle exercise. In patients with aortic regurgitation, resting ejection fraction may overestimate myocardial function. The slope of the pressure-volume relationship measured during afterload stress and left ventricular ejection fraction response to exercise intervention more reliably reflect the degree of left ventricular dysfunction. Circulation 71, No. 1, 31-38, 1985. PATIENTS with aortic regurgitation may remain asymptomatic for many years even with significant left ventricular dysfunction" 2 and the optimal timing of aortic valve replacement is controversial. Left ventricular ejection fraction is often normal at rest,SA but may respond abnormally to exercise.5-9 The mechanism of the abnormal response is difficult to define because of markedly altered loading conditions in such patients.The slope of end-systolic pressure-volume relationship has been shown to be a sensitive index of myocardial contractile state independent of preload.'-'3 The utility of this measurement as an index of myocardial contractility in man has been enhanced since systolic blood pressure measured noninvasively can be substituted for left ventricular end-systolic pressure without significantly altering its validity.'3-'7 The purpose of this study was to determine the systolic blood pressure-left ventricular end-systolic volume (pressure- volume) relationship in patients with aortic regurgitation and to correlate this parameter with left ventricular performance during both isometric handgrip and dynamic bicycle exercise. MethodsStudy patients. Fourteen asymptomatic patients (13 men and one woman, mean age 36 years, range 24 to 44) with isolated moderate-to-severe aortic regurgitation were studied. Four patients had undergone cardiac catheterization and had aortic regurgitation of angiographic grade III out of IV, with no peak systolic pressure gradient, no mitral regurgitation, and normal coronary arteries. The remaining 10 patients had clinical signs of isolated moderately severe aortic regurgitation, with pulse pressure of more than 55 mm Hg and cardiomegaly on radiographs. In all 10 patients echocard...

Assessment of left ventricular long axis contraction can detect early myocardial dysfunction in asymptomatic patients with severe aortic regurgitation

“…4 6 7 Borer and colleagues reported that patients whose ejection fraction decreased on exercise by more than 5% had a 12.5%/year risk of developing heart failure or subclinical left ventricular dysfunction, compared with only 1.9%/year if the ejection fraction response was normal; the risk was 8.8%/year if the ejection fraction on exercise was less than 50% 4. We applied the same cut off to differentiate between patients with good and poor exercise responses; a fall in ejection fraction on exercise of less than 5% was taken as no change, as this value—used by Borer and colleagues—corresponded to more than 2 SD of our intraobserver variability for this measurement.…”

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

“…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 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.…”