[The role of Ca2+, entering the cell during reperfusion, in the mechanism of initiation and maintenance of reperfusion arrhythmias].

: The role of calcium ions entering cells upon reperfusion of ischemic myocardium for reperfusion arrhythmias has been investigated on the model of isolated rat right ventricle perfused through coronary artery. Manipulation by concentration of calcium ions in the reperfusion solution demonstrates that calcium ions entering cells upon reperfusion do not play a major role in the initiation of reperfusion extrasystoles and tachycardias, but have a significant influence on the maintenance of tachycardias. Multielectrode mapping revealed a focal source as the mechanism underlying reperfusion arrhythmias at low concentration or in the absence of calcium ions in the reperfusion solution.