梗死前心绞痛对初次急性心肌梗死后QTd及严重室性心律失常的影响

Effects of preinfarction angina pectoris on severe ventricular arrhythmia and QTd in patients with first acute myocardial infarction

目的 :观察 2 4h内心绞痛发作对初次急性心肌梗死 (AMI)患者住院期间严重室性心律失常及 QT离散度 (QTd)的影响。方法 :184例初次 AMI患者 ,分为梗死前心绞痛 (PA)组 ,5 8例 ;无梗死前心绞痛 (NPA)组 ,12 6例。观察住院期间心脏并发症及 QTd。结果 :两组间一般临床情况、冠心病危险因素、AMI前用药情况、AMI后抗心律失常药物使用、溶栓成功率及入院后肌酸磷酸激酶 (CK)及其 MB亚型 (CK- MB)峰值无显著差异。PA组及 NPA组早期 QTd分别为 (5 6 .2 2± 18.40 )及 (84.45±2 1.90 ) m s,(P<0 .0 5 ) ;晚期 QTd分别为 (5 0 .6 7± 16 .34 )及 (6 4.18± 16 .41) ms(P<0 .0 5 )。PA组严重室性心律失常、心力衰竭、心源性休克发生率及院内心源性病死率明显低于 NPA组。结论 :梗死前心绞痛显著降低 AMI患者住院期间 QTd值及严重室性心律失常的发生率。

Objective: To observe the effects of angina pectoris on severe ventricular arrhythmia and QTd in patients with first acute myocardial infarction(AMI). Methods: One hundred and eight four cases of first AMI were divided into 2 groups: PA group, angina pectoris occurred within 24 h before AMI onset ( n =58), NPA group, no preceeding angina pectoris occurred ( n =126). Occurrence of complications and QTd were investigated during hospitalization. Results: The basic clinical characteristics, coronary risk factors, medication before infarction, treatments after admission with antiarrhythmic agents, site of infarction, successful rate of thrombolysis and peak CK, CK MB were not statistically different. Early QTd in PA group and NPA group were (56.22±18.40) ms vs (84.45±21.90) ms, respectively, P <0.05, late QTd in PA group and NPA group were (50.67± 16.34) ms vs (64.18(16.41) ms, respectively, P <0.05. Comparison with NPA group, incidence of severe ventricular arrhythmia, heart failure, cardiogenic shock and rate of cardiac mortality in hospital was lower in PA group. Conclusion: Preinfarction angina pectoris can significantly reduce the incidence of severe ventricular arrhythmia and QTd in the patients with first AMI, suggesting that these favorable effects might be associated with protective effects of ischemic preconditioning on myocardium and ventricular pump function and improvement of repolarizative asynchronism in ventricular myocardium. [