Forward ejection fraction: a new index of left ventricular function in mitral regurgitation.

Previous studies have shown that a normal LVEF is not a reliable index of LV function in MR. We hypothesized that the forward EF, which is the forward stroke volume (measured by Fick or thermodilution) divided by end-diastolic volume (measured by contrast ventriculography) may be a useful index of LV function, since it represents LV emptying into the aorta. This index was examined in 54 patients with chronic MR who had normal EF (greater than or equal to 50%). There were significant correlations between the forward EF and the end-diastolic volume index (r = -0.69, p less than 0.001), end-systolic volume index (r = -0.64, p less than 0.001), cardiac index (r = 0.43, p less than 0.01), and the ratio of systolic pressure-to-end-systolic volume (r = 0.65, p less than 0.001). Patients were divided into two groups according to the forward EF: group I (n = 34) had forward EF less than or equal to 35%; and group II (n = 20) had forward EF greater than 35%. Of the 32 patients who subsequently underwent mitral valve replacement, 24 patients were in group I and eight patients were in group II. At a mean follow-up of 35 months, four patients died; all of them were in group I. Improvement in functional class occurred in 75% of surgical survivors (80% in group I and 63% in group II, p = NS). These preliminary data suggest that forward EF may be a useful index of LV performance in patients with MR who have normal EF.

Age-related changes in cardiovascular performance in mitral regurgitation: analysis of 61 patients.

This study examines the cardiovascular performance in relation to age in 61 patients with moderate or severe chronic mitral regurgitation (MR). Coronary artery disease (CAD) (50% or more diameter narrowing of one or more major coronary arteries) was present in 20 patients (33%). Patients less than 60 years (n = 33) had lower pulmonary artery pressure, systolic arterial pressure, left ventricular (LV) end-diastolic pressure, and pulmonary artery wedge pressure than the patients greater than or equal to 60 years (n = 28) (p less than 0.05). In the 41 patients without associated CAD, the LV end-diastolic pressure and systemic arterial pressure were higher in patients greater than or equal to 60 years (n = 14) than patients less than 60 years (n = 27) (p less than 0.05). The LV end-diastolic pressure showed an age-related increase in the presence or absence of CAD. Thus, older patients with MR have higher LV end-diastolic pressure, probably because of an increase in myocardial stiffness.