Effects of Halothane, Fentanyl, and Propofol-Fentanyl Anesthesia on Functional Recovery of Stunned Myocardium in Dogs. |
Kyung Yeon Yoo, Gyoung Yub Rhee, In Chae Jang, Chang Young Jeong |
1Department of Anesthesiology, Chonnam National University, Kwang-Ju, Korea. 2Department of Anesthesiology, Kwang-Ju, Korea. |
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Abstract |
BACKGROUND Stunned myocardium may be mediated by intracellular Ca2+ overloading or oxygen derived-free radicals. Halothane and propofol have been shown to block Ca2+ channels. Propofol is also known to have antioxidant properties. The present study was aimed to investigate the effects of anesthetics on recovery of postischemic, reperfused myocardium in open-chest dogs. Incidence of ventricular arrhythmia upon ischemia and reperfusion was also determined. METHODS Forty dogs were subjected to 15 min occlusion of left anterior descending coronary artery (LAD) followed by 3 hr reperfusion during halothane (n=10), fentanyl (n=12), or propofol plus fentanyl (n=11) anesthesia. Regional contractile function was assessed using percent systolic shortening (%SS), the preload recruitable stroke work slope (Mw), and peak systolic intramyocardial pressure (IMPs).
Diastolic function was evaluated using time constant for isovolumic intramyocardial pressure decline of left ventricle (IMP-tau) and percent post-systolic shortening (%PSS). RESULTS %SS in the halothane, fentanyl, and propofol-fentanyl groups was similar at 3 hours of reperfusion (58%, 60%, and 55% of baseline value, respectively). Moreover, Mw recovered to the baseline values in the early reperfusion period in all three groups.
However, IMP-tau was significantly prolonged in the halothane group throughout the 3 hour reperfusion period, whereas it remained unchanged in the fentanyl and propofol-fentanyl groups. Coronary occlusion was associated with 9, 33, and 0% mortality rate due to ventricular fibrillation upon ischemia and reperfusion in the halothane, fentanyl, and propofol-fentanyl groups, respectively. CONCLUSION These findings indicate that halothane, but not fentanyl and propofol- fentanyl, impairs myocardial relaxation, while recovery pattern of contractile function do not differ among three groups, and that halothane and propofol reduce reperfusion arrhythmia in the canine model of myocardial stunning. |
Key Words:
Heart stunned myocardium; diastolic function; systolic myocardial function; Anesthetics; volatile halothane; Anesthetic; intravenous fentanyl; propofol |
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