Intracellular calcium handling in isolated ventricular myocytes from patients with terminal heart failure.

Abstract

BACKGROUNDExperiments were performed in human ventricular myocytes to investigate properties of excitation-contraction coupling in patients with terminal heart failure. Myocytes were isolated from left ventricular myocardium of patients with cardiac failure caused by dilated or ischemic cardiomyopathy undergoing transplantation. These results were compared with those obtained from cells of healthy donor hearts that for technical reasons were not suitable for transplantation.METHODS AND RESULTS[Ca2+]i transients and Ca2+ currents were recorded from isolated cells under voltage clamp perfused internally with the Ca2+ indicator fura 2. In cells that were stimulated externally, the cell-permeant form of the indicator, fura 2-AM, was used. When action potentials were to be recorded, cells were stimulated in current clamp mode. Unstimulated Ca2+ current densities were not significantly different in myopathic and control cells. In diseased myocytes, resting [Ca2+]i levels were 165 +/- 61 nmol/l, compared with 95...