Contraction-relaxation coupling is unaltered by heart failure status in human myocardium

According to the Bowditch effect, increased cardiac contraction frequency leads to stronger contraction. To maintain end-organ perfusion, for each change in contractile rate, a compensatory parallel change in relaxation rate is necessary Heart failure (HF) was once thought to be primarily a disease of contractility, but it has become clear that it presents with relaxation dysfunction and insufficient ventricular filling before contractile pathology in more than half of HF patients. Whether contraction and relaxation rates are coupled in human myocardium is not well understood.