Potentials and limitations of ventricular torsion as indicator of cardiac function.

New non-invasive imaging techniques allow quantification of torsion of the left ventricle (LV). Presently, it is not well know what torsion can add as an indicator of left ventricular pump function. A frame work for understanding of cardiac motion has been designed that is based on general principles of mechanics. In this frame work experimental and clinical findings on torsion were related to various indices of LV function. The time courses of torsion and volume have much information in common. However, the rate of torsion during isovolumic relaxation provides important information on rate of LV pressure decay. Most importantly, assessment of the relation between torsion and the changing inner diameter during ejection renders unique information about the transmural gradient of contractile performance of the LV myocardium.