Objective:To explore the malignant arrhythmia of swine models in plugging left anterior descending artery (LAD) at different segments and its association with QT and QTc interval. Methods:Total 22 swine were chosen to undergo occlusion of coronary artery with balloon angioplasty. The animals were randomly divided into 3 groups according to the occlusion position of balloon:①Sham group:no occlusion of LAD(n = 4);② The occlusion at lower 1/3 segment of LAD group(n = 9); ③ The occlusion at middle segment of LAD group(n = 9). Then the incidence of malignant arrhythmia (ventricular tachycardia or ventricular fibrillation) was observed in the process of molding,and the QT and QTc interval were analyzed after models made successfully. Results:The incidence of ventricular fibrillation in the middle segment of LAD plugging group was significantly higher than the lower 1/3 segment of LAD plugging group (100% vs 33.33%,P < 0.05). After the models constructed,the QT interval between the two groups showed no significant difference [(362.11±29.18) ms vs (338.78 ± 22.65) ms,P > 0.05]. However,the QTc interval was significantly longer in the middle segment of LAD plugging group than in the lower 1/3 segment of LAD plugging group[ (462.67 ± 27.55) ms vs (425.56 ± 21.96)ms,P < 0.01). Conclusion:Malignant arrhythmia after acute myocardial infarction in swine models was associated with prolonged QTc interval.