Influence of prosthesis size and left ventricular mass on left ventricular diastolic reserve in patients with aortic valve prostheses.

ABSTRACT

BACKGROUND AND AIM OF THE STUDY The study aim was to determine the influence of valve size and left ventricular (LV) mass on long-term LV diastolic reserve in patients subjected to aortic valve replacement for stenosis. METHODS: Seventy-four patients (33 women, 41 men; mean age 64 years) after aortic valve replacement with 40 pericardial bioprostheses and 34 bileaflet mechanical prostheses were studied. All valves were of nominal size 19, 21 or 23 mm. The patients were studied by Doppler echocardiography, at rest and during peak effort, between 12 and 47 months after valve replacement. RESULTS: All patients achieved significantly increased heart rate, blood pressure and cardiac output in response to effort. Effort also significantly modified transvalvular pressure drops and valve areas. The mean diastolic reserve was 29.3 ml, and mean stroke volume reserve 23.2 ml; in neither case were there any significant differences between valve types, or among valve sizes. CONCLUSION: At about one year after surgery, the diastolic reserve of patients subjected to aortic valve replacement on account of stenosis was considerable, and independent of valve size. Despite the persistence of LV hypertrophy after valve replacement, LV diastolic function during effort was similar to that of the normal heart.