Evidence for Functional Relevance of an Enhanced Expression of the Na ⁺ -Ca ²⁺ Exchanger in Failing Human Myocardium

The increased expression of the Na(+)-Ca2+ exchanger is a possible explanation for the increased inotropic potency of the Na+ channel activator BDF 9148 in failing human myocardium. The increase in exchanger molecules could be of functional relevance for the modulation of cardiac contractility by agents that increase the intracellular Na+ concentration. Enhancement of Na(+)-Ca2+ exchanger activity might be a powerful mechanism for increasing cardiac contractility in chronic heart failure.