Response to heart failure therapy: Ventricular volume changes vs. 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 is the stage when therapy should be intensified. The dynamic shape changes during the cardiac cycle in valvular regurgitation, when ventricular volumes are within the normal range, have proved that shape changes are clearly dissociated from volume changes in the early stages. In advanced heart failure, several therapeutic interventions to decrease the ventricular equator and hence the volume, have been tried with variable success. However, the ventricular shape may still be spherical, leading to suboptimal function. The aim in any therapy for heart failure should therefore be to achieve near normal left ventricular anatomy and physiology, with shape assessment as the surrogate marker of therapeutic success.