Effect of local radiofrequency denervation on ventricular effective refractory period and ventricular arrhythmia susceptibility after acute myocardial infarction / 第二军医大学学报

ABSTRACT

Objective To introduce a new method of local denervation by ablation and to observe its effect on ventricular effective refractory periods and ventricular arrhythmia susceptibility after acute myocardial infarction. Methods Eighteen mongrel dogs were used to make myocardial infarction model by ligation of the 1st diagonal artery. Then local denervation was achieved by using six radiofrequency ablations (each at 8 W for 2 min) along the left anterior descending artery. Effective refractory periods were tested at six sites on the left ventricular epicardium (above, in and below the infarction areas, 2 sites each area) before and after local denervation by S1S2 stimulation. Ventricular arrhythmia was also induced after myocardial infarction and after denervation by burst pacing, and the number of arrhythmia episodes was recorded. Results The effective refractory periods were significantly prolonged after ablation ([191. 3±24. 9] ms vs [209. 0±27. 2] ms, P<0. 05). And the prolongation of effective refractory periods in infarcted area ([11. 3±8. 8] ms) was significantly shorter than those in the other 2 areas ([23. 2±10. 2] ms and [18. 7±11. 5] ms). After ablation, 8 of the 11 susceptible dogs were free of induced ventricular arrhythmia, while 3 of them were still inducible by burst pacing. The induced ventricular arrhythmia rate was reduced from 61.1% (11/18) to 16.7 %(3/18) (P = 0. 007). Conclusion The method in this study is promising for preventing ventricular arrhythmia in patientswith acute myocardial infarction receiving percutaneous coronary intervention.