[The defining role of calcium entering cells during ischemia as the mechanism for initiating reperfusion arrhythmias].
The role of calcium ions entering cells upon both reperfusion and previous ischemia for reperfusion arrhythmias has been studied on the experimental model of isolated rat right ventricle perfused through coronary artery. Manipulation by concentration of calcium ions in both perfusion and reperfusion solutions demonstrates that calcium ions entering cells during ischemia but not upon reperfusion play a dominant role in the initiation of reperfusion tachysystoles (RTS) and reperfusion extrasystoles. It is shown that mechanisms of reperfusion fibrillations (RF) are more sensitive than ones of RTS to changes of the intracellular calcium concentration. For example, RF have been easily suppressed by calcium concentration decreasing at any stage of the experiment: upon reperfusion, or during previous ischemia, whereas RTS have not been suppressed even under total removal of calcium from solutions either before initiation of ischemia or during following reperfusion. Multielectrode mapping revealed focal sources arising as the mechanism underlying not only reperfusion arrhythmias as it has been shown before [4.7] but also arrhythmias that have been observed through experiments.
Burashnikov
A Iu
AIu
Medvinskiĭ
A B
AB
hkin
N I
NI
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004566:Electrodes; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar
D002118:Calcium