Left ventricular contractile function in aortic stenosis evaluated by isovolumic and ejection phase indexes.

This study is to reappraise the usefulness of isovolumic as compared to ejection phase indexes for detecting abnormal left ventricular contractile function patients with a common hemodynamic abnormality, namely, chronic left ventricular pressure overload. In 41 subjects with pure or predominant aortic stenosis left ventricular pressure measurements were performed by micromanometry. Single-plane left ventricular cineangiograms were carried out in the right anterior oblique (RAO) and the A-P position. The isovolumic contractile indexes we used in this study were peak measured velocity of shortening of the contractile elements (Vpm) and Vmax obtained from linear extrapolation of total pressure-velocity curves. The end-diastolic and end-systolic RAO cineventriculograms served for the calculation of the ejection phase parameters mean velocity of circumferential fiber shortening (VCF) and mean normalized systolic ejection rate (MNSER). Of the 41 patients, Vpm was depressed in 16 (39 per cent), Vmax in 17 (42 per cent), VCF in 12 (29 per cent), and MNSER in 14 (34 per cent). When the isovolumic and the ejection phase parameters were combined, 24 patients (59 per cent) were found to have at least one of the four contractile indexes below normal. In 26 of the 41 patients the isovolumic and the ejection phase indexes provided the same conclusions as to normality of left ventricular function. In contrast, 15 patients showed discordant isovolumic and ejection phase indexes. An increased left ventricular end-diastolic pressure was only inconsistently related to an abnormal left ventricular function because in 7 of 28 patients with an end-diastolic pressure above 14 mm. Hg all contractile indexes were normal. Furthermore, a normal end-diastolic pressure was present in three of 24 patients with depressed myocardial function. It is concluded that in chronic left ventricular pressure overload from aortic stenosis neither the isovolumic nor the ejection phase indexes are superior in sensitivity for assessing contractile function. In this clinical setting the combination of both types of indexes appears to be the most reliable way for identifying patients with depressed contractile function of theleft ventricle in the basal state.