Left ventricular diastolic filling pattern predicts cardiopulmonary determinants of functional capacity in patients with congestive heart failure

Background Abnormalities of diastolic function are an important determinant of exercise intolerance in patients with heart failure. However, the relat ion between left ventricular filling pattern and cardiopulmonary exercise p erformance has not been adequately studied. Methods Thirty-one patients with idiopathic (n = 14) or ischemic (n = 17) d ilated cardiomyopathy, demonstrated by coronary angiography, and radionucli de ejection fraction 30.5% +/- 9% underwent cardiopulmonary exercise testin g with a modified Naughton protocol and a complete echocardiographic study. Patients were subdivided into restrictive and nonrestrictive groups accord ing to their Doppler transmitral flow pattern. Gas exchange data were measu red during exercise testing. The relation of left ventricular filling patte rn to cardiopulmonary parameters was assessed in both groups. Results Exercise duration was similar in the restrictive and nonrestrictive groups but significant differences were Found in oxygen consumption (VO2) at peak exercise (14.3 +/- 2.4 vs 20.4 +/- 4.7 mL/kg per minute; P <.001) a nd at the anaerobic threshold (VO2AT) (13 +/- 2.2 vs 17.3 +/- 3 mL/kg per m inute; P <.001). Simple linear regression analysis revealed that both peak VO2 and VO2AT were significantly correlated with the ratio of peak early (E wave) to late (A wave) transmitral filling velocity, early filling deceler ation time, atrial filling fraction, and A-wave velocity but not with left ventricular ejection fraction. Multivariate regression analysis gave only t he peak A-wave velocity as an independent predictor for both peak VO2 and V O2AT Conclusions In patients with heart failure, abnormalities of diastolic func tion are the most important determinant of exercise intolerance. A restrict ive transmitral flow pattern by Doppler echocardiography is a marker of dim inished cardiopulmonary exercise performance in these patients.