974-42 Determinants of Pulmonary Hypertension Associated with Left Ventricular Dysfunction

The elevation of systolic pulmonary artery pressure (S-PAP) is an important prognostic variable in patients with left ventricular dysfunction (LVD). The potential determinant of pulmonary hypertension have not been consistently measured and remain ill defined. In 93 patients (age=6B±13 years) with primary LVD (Ejection Fraction <50%, mean±SO=31±10%), the S-PAP was prospectively measured using Doppler tricuspid regurgitant velocity. The correlations between S-PAP and LV diastolic volume (R=0.19, P=NS). LVejection fraction (R=–0.23, p=0.024). cardiac index (R=–0.22, P=0.04). left atrial volume (R=0.31, P=0.002) were weak. Stronger correlations were observed with mitral regurgitant fraction (R=0.46, p=0.0001). effective regurgitant orifice (ERO, R=0.48, P=0.0001), mitral deceleration time (DT) R=–0.62, P=0.0001) and E/A ratio (R=0.43, P=0.002). With multivariate analysis, the only independent predictors of S-PAP were mitral deceleration time (P=0.0001), mitral effective regurgitant orifice IP=0.0003) and age (P=0.007). The S-PAP of patients with similar EF are shown below:DT > 150 (msec)DT ≤150 (msec)PEF:≤3039±1361±1200001EF ≤3040±1057±1000001ERO <15 (mm2)ERO≤ 15 (mm2)PEF:≤3049±1660±13002EF ≤3040±1055±110.0001We conclude that in patients with primary systolic LV dysfunction, the independent determinant of pulmonary hypertension are the diastolic stiffness of LV as estimated by the mitral deceleration time and the degree of functional mitral regurgitation as measured by the effective regurgitant orifice but not by the degree of LV systolic dysfunction. These data help explain the wide variation of hemodynamic compromise in patients with similar degree of LV dysfunction