Combined Systolic Time Intervals and M-Mode Echocardiography in the Evaluation of Central Hemodynamics in Primary Pulmonary Hypertension

Abstract

8 patients with moderate to severe primary pulmonary hypertension underwent systolic time intervals, M-mode echocardiography, and direct hemodynamic studies in order to determine the correlation between noninvasive parameters and hemodynamic variables and to evaluate the utility of these noninvasive studies in primary pulmonary hypertension. The ratio of the pre-ejection period to left ventricular ejection time (PEP/LVET) of the systolic time intervals was abnormally increased ( > 0.42) for each subject; the increase in the PEP/LVET was secondary to a shortening of the left ventricular ejection time in 4 patients, prolongation of the pre-ejection period in 1, or a combination of such, noted in 3. In contrast, echocardiographic parameters of left ventricular function, specifically, percent change in the minor axis of the left ventricle with systole, velocity of circumferential fiber shortening, and ejection fraction, were normal. In addition, a very good correlation was noted between PEP/LVET and total pulmonary resistance (r value = -0.89), while the echocardiographic parameters correlated well with stroke volume and cardiac indices (r values ranged from 0.68 to 0.72). These results indicate that in primary pulmonary hypertension, systolic time intervals provide an estimation of overall cardiac-cardiovascular performance, 653 Means Hallrather than left ventricular function alone, which in turn, is validly examined by M-mode echocardiography