Abstract
The usefulness of systolic time intervals, diastolic time intervals and echocardiography in evaluating left ventricular (LV) function was determined in 69 patients with severe congestive heart failure. All systolic time intervals were markedly abnormal (preejection period/LV ejection time 0.59 ± 0.18 vs 0.30 ± 0.04, preejection period index 170 ± 37 vs 117 ± 11, LV ejection time index 372 ± 26 vs 410 ± 17; patients vs control subjects, p < 0.05). Diastolic time intervals in patients were not different from those in control subjects. Echocardiographic measurements were all markedly abnormal (LV end-diastolic dimension 6.9 ± 1.0 vs 4.8 ± 0.4 cm, patients vs control subjects, p < 0.05). No pattern of abnormalities distinguished ischemic cardiomyopathies from idiopathic dilated cardiomyopathies. The presence of LV conduction delay did not substantially alter results, except that exclusion of patients with LV conduction delay normalized the total time of systole (QA2) index (from 542 ± 40 to 531 ± 31 ms) and reduced but did not normalize prolongation in the preejection period index (from 170 ± 37 to 162 ± 29 ms). No systolic or diastolic interval strongly correlated with any hemodynamic or other independent measure of LV performance. Twenty-four patients were given inotropic or unloading agents, which significantly improved hemodynamic values. Systolic and diastolic intervals were measured at baseline and at maximal hemodynamic effect. The correlation of changes in hemodynamics with changes in systolic and diastolic intervals was only modest. Thus, although systolic time intervals and associated echocardiographic measurements can detect abnormal LV function, they cannot reliably detect a change in LV function or distinguish gradations of abnormality. Diastolic intervals correlate only modestly with changes in hemodynamic values.
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