The response of the abnormal heart to exercise.

NUMEROUS STUDIES have established the constant association of certain hemodynamic abnormalities and the clinical state of congestive heart failure. Indeed, certain abnormalities are particular to this state: for example, elevation of right ventricular diastolic pressure at rest in patients with acquired heart disease is universally found in the presence of right ventricular failure; similarly, resting pulmonary artery hypertension is associated with left ventricular failure. On the other hand, certain other circulatory abnormalities, notably a reduced cardiac output or an increased blood volume, while frequently seen in conjunction with congestive heart failure, do not invariably accompany it and may be observed in its absence. Since certain pressure-flow abnormalities also have been found in the noncongested state either at rest or more commonly during exercise,'-8 it has been concluded that there is a fairly wide spectrum of hemodynamic disturbances in the abnormal heart.8 Lewis et al.2 even proposed a hypothetic series of curves to describe left ventricular performance as the heart progressively fails. The purpose of this study was to establish the earliest type of hemodynamic dysfunction in patients with myocardial disease and to characterize the further stages of cardiac dysfunction up to and including advanced congestive heart failure. Patients with cardiac disease who had never been in failure, those who had recovered from clinical congestive