The Relationship between ST-T Electrical Alternans on EKG and Ventricular Arrhythmia

ABSTRACT

In order to observe the development of ventricular arrhythmia during regional myocardial ischemia and reperfusion, especially under the presence or absence of ST-T electrical alternans on epicardial EKG. The proximal left descending coronary artery(LAD) was ligated for 20 minutes and then reperfused suddenly in twenty-three cats. Standard lead EKG(Lead??, chest lead EKG and epicardial lead EKG were recorded simultaneously during the occlusion and reperfusion respectively. During the ligation of LAD, STEA was observed in thirteen cats(56.5%). In occlusion period, the incidence of ventricular tachycardia in STEA positive group was significantly higher than in the negative group(p<0.01) and arrhythmic score was significantly higher(p<0.005) also In the reperfusion period the incidence of vefntricular fibrillation in STEA positive group was significantly higher than in the negative group(p<0.025). But there was the tendency to be higher in arrhythmic score of STEA positive group. There were no differences in heart rate, systolic left ventricular pressure, ST elevation and ST width in both groups. Most forms of ST-T of sinus rhythm before and after development of ventricular premature beat was low form(L). It was concluded that at the presence of STEA on EKG, the incidence of ventricular arrhythmia was more prevalent. So, STEA can be available as a marker of ventricular arrhythmia and prognostic factor.