Transient Occlusion of the Left Anterior Descending Coronary Artery in Pigs

Abstract

The purpose of this study was to define a model of transient coronay occlusion (CO) in the open-chest pig. The left anterior descending (LAD) coronary artery was occluded at its mid-length in 45 white pigs and reperfusion was performed after 30, 45, 60 or 90 min. One group of 9 animals with permanent CO served as control. During the occlusion period only slight hemodynamic changes were observed, but a period of ventricular arrhythmias was consistently observed between 15 and 30 min after CO, with an incidence of ventricular fibrillation (VF) in 8 cases (18%). All but 1 of the animals with VF could be defibrillated in less than 1 min or 3 electrical countershocks. Complex arrhythmias with marked hypotension were consistently observed after reperfusion. Histological examination showed a patent coronary artery lumen and minor changes in the LAD coronary artery at the site of occlusion in the reperfused animals and completely occluded arteries in the control group. Two pigs (4.4%) died during the night following CO. Transient CO can be performed safely in pigs with a very low complication rate and a high 24-hour survival rate.

Comparative study of left ventricular wall motion and of reperfusion arrhythmias as signs of successful coronary recanalization

“…In our study the establishment of wall motion was achieved after 12.26 ± 4.4 min, so we did not have cases of prolonged recovery. However, after 15 min of occlusion and ischemia, segmental wall motions were established 30-min later, which corresponds to the literature data (Galinanes et al 1987;Nearing et al, 1994;Rosenbaum et al, 1994).…”

CaMKII inhibition has dual effects on spontaneous Ca2+ release and Ca2+ alternans in ventricular cardiomyocytes from mice with a gain-of-function RyR2 mutation

“…In paper 3, an in vivo model of MI in pigs was used to investigate the effect of the strong antioxidant NAC on reperfusion arrhythmias. The thorax was opened by sternotomy and MI started by clamping of the LAD for 90 min, before reperfusion for 1 h. The benefit of open-thorax surgery includes the ability to easily access and control the point of occlusion (179,180). One can also observe contractile function visually during the experimental protocol.…”

Myocardial oxidative stress is increased in early reperfusion, but systemic antioxidative therapy does not prevent ischemia-reperfusion arrhythmias in pigs

“…We therefore only took samples from all areas at 60 min reperfusion, when the protocol was completed and immediately before the pigs were euthanized. Additionally, this procedure exposes the heart to unphysiological temperatures, and heat loss may be further exaggerated by evaporation, resulting in cooling of the epicardial surface ( 59 – 61 ). Although we aimed to preserve a constant temperature by superfusing the heart with warmed NaCl, this could have affected arrhythmia incidence in our study, although similarly in both the Ctrl and NAC groups ( 62 ).…”