Left ventricular filling measured by Doppler echocardiography during dynamic exercise in patients with myocardial...

To assess left ventricular diastolic properties in response to dynamic exercise, mitral inflow velocity integrals were measured by pulsed-wave Doppler echocardiography in ten patients with myocardial infarction and in ten normal subjects, and simultaneous left ventricular pressure was obtained with micromanometry in the patients. Early filling velocity integrals were maintained in the patients during exercise. Late filling velocity integrals were not augmented during exercise in the patients, but were increased in the normal subjects. In the patients, there was an increase in mitral valve opening pressure, left ventricular end-diastolic pressure, and the time constant of left ventricular isovolumic pressure decay. The lowest diastolic pressure and the number of time constants that had elapsed before the lowest diastolic pressure remained unchanged. These results show that in patients with myocardial infarction, early filling is maintained by an increase in driving pressure during exercise, despite incomplete relaxation. Augmentation of late filling, seen in normal subjects, is impaired in patients with myocardial infarction, probably due to an increase in left ventricular stiffness.