Pattern of left ventricular diastolic filling associated with right ventricular enlargement

Abstract

Right ventricular (RV) dilatation associated with pressure overload may alter left ventricular (LV) geometry resulting in abnormal diastolic function as demonstrated by a smaller LV diastolic volume for a given LV diastolic pressure. To determine whether abnormalities in LV geometry due to RV dilatation result in abnormalities in the LV diastolic filling pattern, we obtained pulsed Doppler transmitral recordings from 23 patients with RV dilatation with RV systolic pressure estimated to be <40 mm Hg (group 1), 18 patients with RV dilatation and RV systolic pressures ≥ 40 mm Hg (group 2) and 33 normal patients. RV systolic pressures were estimated from continuous wave Doppler peak tricuspid regurgitation velocities using the modified Bernoulli equation. Diastolic filling parameters in group 1 patients were similar to normals. In group 2 patients, increased peak atrial filling velocity (76 ± 14 vs 57 ± 12 cm/s, p < 0.001), decreased peak rapid filling velocity/peak atrial filling velocity (1.1 ± 0.4 vs 1.5 ± 0.4, p < 0.01), increased atrial filling fraction (41 ± 14 vs 30 ± 10%, p < 0.01) and prolongation of the atrial filling period (171 ± 47 vs 152 ± 39 ms, p < 0.05) were noted compared with the normal group. RV enddiastolic size and LV end-systolic shape were significantly correlated with the atrial filling fraction in group 2 patients. In patients with RV dilatation and RV systolic pressures ≥ 40 mm Hg, there is increased reliance on atrial systolic contribution to the LV filling volume.