Ventricular interdependence: how does it impact on hemodynamic evaluation in clinical practice?

Abstract

The left (LV) and right ventricles (RV) are enclosed in a stiff envelope, the pericardium. They have similar enddiastolic volumes, and there is no free space for acute ventricular dilatation within a normal pericardial space. Thus, when RV end-diastolic volume increases owing to increased RV loading, it can only occur at the expense of the space devoted to the left ventricle, which is prevented from dilating to as large an end-diastolic volume as it would otherwise given its distending pressure. From a practical point of view this reduced LV end-diastolic volume is accompanied by decreases in LV diastolic compliance, such that for the same LV distending pressure LV end-diastolic volume is less. This point was described in a previous Physiological Note [1]. LV impaired relaxation by RV enlargement is evidenced by Doppler examination of mitral flow velocity (Fig. 1).