Mechanical determinants of myocardial energy turnover

Energy turnover of the left ventricle does not differ in isovolumic contractions and contractions where pressure is released from peak to zero. This experimental result corresponds to predictions from a time varying elastance model of the mechanical and energetic properties of the left ventricle. To assess the validity of this model for cardiac muscle in general, experiments were designed to investigate whether mechanical and energetic behaviour of isolated cardiac muscle preparations could also be predicted from the time varying elastance model. The results obtained so far indicate, however, that not all experimental results can be accommodated by the model. This suggests that the value of the model may be limited.