Assessment Of Response To Heart Failure Therapy: Ventricular Volume Changes Versus Shape Changes

Abstract

The prolate ellipsoid left ventricular geometry is crucial for its unique contraction and relaxation patterns. Perturbations in optimal cardiac function preceding overt heart failure ensue when this ellipsoid shape assumes a more spherical configuration. This stage of spherical configuration, prior to overt dilatation, is when therapy should be intensified. The dynamic shape changes during the cardiac cycle of systole and diastole in valvular regurgitations when ventricular volumes are within normal range have proved that shape changes are clearly dissociated from volume changes in the early stages. In the scenario of advanced heart failure, several therapeutic interventions have been tried with variable success. These therapies aim at decreasing the ventricular equator, and hence its volume. However, the ventricular shape may still be spherical leading to suboptimal function. The aim in any therapy for heart failure should be therefore to achieve near normal left ventricular anatomy and physiology, with shape assessment as the surrogate marker of therapeutic success.