The Value Of The Planar Qrs-t Angle On Cardiac Dysfunction In Patients With Old Myocardial Infarction

ObjectiveTo explore a method of surface electrocardiogram for assessing cardiac dysfunction in patients with old myocardial infarction.Methods1000 patients with old myocardial infarction in Anzhen hospital from Jan, 2008 to Jan,2009 were analyzed retrospectively. Old myocardial infarction was defined after the acute myocardial infarction 6 months (≥6 months), body surface electrocardiogram show pathological Q wave at least in two lead. According to the left ventricular ejection fraction (LVEF),1000 patients were divided into 2 groups:Heart failure group (LVEF< 50%, n=297) and heart function normal group (LVEF>50%, n=703). Respectively take the planar QRS-T angle> 80°,> 90°,> 100°as the cutoff, analyzed assessment value of planar QRS-T angle for the LVEF of old myocardial infarction.ResultsAmong these 1000 patients,822 (82.2%) were male and 178(17.8%)were female,the mean age was 59.3±10.5 years (34-89 years).485 (48.5%) were anterior wall myocardial infarction,475 (47.5%) were inferior wall myocardial infarction, another mode were less. In 1000 patients,554(55.4%)hypertension, 309 (30.9%) diabetes mellitus,433 (43.3%) dyslipidemia,580 (58.0%) smokero The average planar QRS-T angle was 88.5±50.6°. The planar QRS-T angle<80°was 366,80.1°-90°was 22 examples,90.1°-100°was 190 examples, > 100°422 examples, respectively take the planar QRS-T included angle> 80°, > 90°,> 100°as the cutoff, the ROC curve analysis demonstrated that diagnosis sensitivity of every cueoff is 63%,76%,56%, the specificity is 69%,74%,81%, the Area Under Curve (AUC)is 0.27,0.72,0.31, so the planar QRS-T angle> 90°had optimal sensitivity and specificity, the AUC is biggest. Partial correlation analysis demonstrated that the planar QRS-T angle and LVEF was negative correlation (r=-0.406, p< 0.01), the LVEF was lower, the relationship with planar QRS-T angle was better. In the anterior wall myocardial infarction, the sensitivity and the specificity of the planar QRS-T angle> 90°for heart failure is 91%,48%, the AUC is 0.72; in the inferior wall myocardial infarction, the planar QRS-T angle> 90°respectively is 89%,50%, the AUC is 0.69.compared with anterior wall myocardial infarction, the sensitivity and the specificity of the planar QRS-T angle> 90°for heart failure is better. the smoking history, the sex, the dyslipidemia exceptionally had not affected to the planar QRS-T angle, P> 0.05.ConclusionThe planar QRS-T angle and LVEF of old myocardial infarction patients is negative correlation, the larger the planar QRS-T angle is, the lower the LVEF is. The planar QRS-T angle> 90°had optimal sensitivity and specificity(76%,74%)for cardiac dysfunction in old myocardial infarction patients. the planar QRS-T angle may be an easy and feasible index for assessing cardiac dysfunction in patients with old myocardial infarction.