Sustained left ventricular diastolic dysfunction after exercise in patients with dilated cardiomyopathy

To investigate the recovery process of exercise induced diastolic dysfunction in heart failure, using Doppler echocardiographic techniques.

Transmitral flow velocity profiles and standard noninvasive haemodynamic indices were obtained serially over seven days after symptom limited bicycle exercise tests in 18 patients with dilated cardiomyopathy and eight normal subjects. In three patients with cardiomyopathy we also measured the pulmonary capillary wedge pressure for 24 hours after exercise.

The intensity of exercise, as assessed by respiratory gas analysis, was lower in patients with dilated cardiomyopathy than in normal subjects. Despite the higher exercise level, all haemodynamic variables returned to baseline within one hour after exercise in normal subjects. In contrast, patients with dilated cardiomyopathy showed a sustained decrease in the peak early diastolic filling velocity and a sustained increase in the deceleration time of early filling for 24 hours or more after exercise. Because other haemodynamic variables recovered within one hour after exercise even in patients with dilated cardiomyopathy, the postexercise changes in ventricular filling were not explained by changes in loading conditions.

Exercise induced diastolic left ventricular dysfunction of the failing heart persists for 24 hours or more after exercise. The efficacy of exercise training on a daily basis in dilated cardiomyopathy requires further evaluation.