Bilateral stellate ganglion block attenuates myocardial ischemia and ventricular arrhythmia

Abstract

Stellate ganglion block (SGB) is a useful procedure to relieve symptoms of sympathetically maintained pain. However, little is known about its effect on myocardial ischemia. Thus, the aim of this study was to investigate the effects of bilateral stellate ganglion block (SGB) on acute myocardial ischemia and its effect on ventricular arrhythmia in ischemic rats. Under general anesthesia with isoflurane, thirteen Sprague-Dawley rates, weighing 290–400g, were instrumented with arterial and left ventricular catheters and EKG electrodes. Then the rats were divided into 2 groups: Group I (N=6: treatment group), underwent bilateral SGB before a 10 min coronary artery occlusion and followed by a 30 min reperfusion period. Group II (N=7: control group) underwent a similar ischemic insult without SGB. We recorded central and peripheral hemodynamics and arrhythmias. Bilateral SGB was performed according to our newly developed technique using 0.2 ml of bupivacaine 0.25%. Ten minutes after coronary artery occlusion, the ST segment increased from a baseline of 0 to 0.063 ± 0.03 mV in group I animals, and from 0 to 0.5 ± 0.06 MV in group II animals (P<0.001). Furthermore, 5 out of 7 rats in group II had ventricular tachycardia or fibrillation as the result of coronary occlusion and reperfusion injury. On the contrary, only 1 out of 6 rats in group I had ventricular tachycardia from similar myocardial insult. We conclude that bilateral stellate ganglion block attenuated the ST segment changes and arrhythmias associated with acute myocardial ischemia in rats. Further studies are underway to study its underlying mechanisms.