Partial hindlimb occlusion during coronary artery occlusion reduces the susceptibility to ventricular arrhythmias via the intrinsic adenosine receptor system in conscious rats

Abstract

Temporary occlusion of coronary arteries can lead to potentially lethal arrhythmias. The arrhythmias are triggered directly by ischemia or during the reperfusion phase. Remote conditioning induced by ischemia in distant organs protects the heart from ischemic/reperfusion injury. However, the effect of remote conditioning on ischemia‐induced ventricular arrhythmias is unknown. Therefore, we tested the hypothesis that partial hindlimb occlusion during coronary artery occlusion reduces the susceptibility to ventricular arrhythmias. To test this hypothesis, 7 rats were instrumented for recording arterial pressure and ECG. A Doppler ultrasonic flow probe and vascular occluder were placed around the terminal aorta. Finally, a snare was placed around the left main coronary artery. The response to coronary artery occlusion during partial hindlimb occlusion was determined in conscious rats. Occlusion of the left main coronary artery resulted in tachy‐arrhythmias that culminated in ventricular fibrillation within 4.56 ± 0.15 min. Partial hindlimb occlusion during coronary artery occlusion culminated in ventricular fibrillation within 6.29 ± 0.49 min. Adenosine receptor blockade (theophylline, 10 mg/kg) attenuated the cardioprotective effects of remote conditioning (4.62 ± 0.79 min). Supported by HL67713