Myocardial dysfunction after electrical defibrillation.
We hypothesized that electrical shocks that defibrillate hearts successfully also produce myocardial injury, but only in settings in which the myocardium is underperfused. Myocardial function was measured in isolated, conventionally perfused or underperfused rat hearts during sinus rhythm and conventionally perfused or underperfused hearts during ventricular fibrillation (VF) after delivery of a sham, a 0.4 J, or a 0.7 J shock. In underperfused hearts, the dP/dt, negative dP/dt, left ventricular diastolic pressure and left ventricular pressure-volume relationships demonstrated significant impairment in myocardial function. Impairment increased with the higher energy shocks. This contrasted with normally perfused hearts, whether in sinus rhythm or during VF, in which shocks resulted in no significant impairment. Electrical shocks therefore produce myocardial injury but only when myocardial perfusion is reduced.
Institute of Critical Care Medicine, 1695 North Sunrise Way, Building #3, 92262, Palm Springs, CA, USA.
Hitoshi
H
Yamaguchi
Max
M
Weil
Wanchun
W
Tang
Takashi
T
Kamohara
Xiaohua
X
Jin
Joe
J
Bisera
D000818:Animals; D009202:Cardiomyopathies / Q000209:etiology*; D003326:Coronary Circulation / Q000502:physiology; D004554:Electric Countershock / Q000009:adverse effects* / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D014693:Ventricular Fibrillation / Q000150:complications