Cardiac Death in Patients with Peripheral Vascular Disease and QT Dispersion

In patients with peripheral artery disease, additional cardiac diseases such as coronary artery disease and hypertension are frequent findings. The existence of coronary atherosclerosis is the Icading factor predicting prognosis. The aim of study was to investigate cardiac death in paticnts with peripheral artery disease without cardiac symptoms and its relation with QT dispersion. The study group consisted of 35 patients (aged 61 ±7 years, 32 males, 3 females) who underwent surgical treatmont because of peripheral arteriopathy and 72 age-matched controls (aged 61±1 years, 54 males, ı8 females). In all subjects, risk factors wcre evaluated with physical examination and laboratory findings. Echocardiographic and 12- lead electrocardiographic examinations were made and QTc interval and QT dispersion were calculated. The study group was followed for two years and cardiac deaths were recorded. Echocardiographic findings were normal in 13 patients (37%), left ventricular hypertrophy and left ventricular dilatation (isolated or accompanying an increase in left ventricular wall thickness) were detected in the remaining patients (63% ). In the control group, echocardiographic findings were normal except in 2 subjects (%3). QT, QTc interval and QT dispersion were significantly prolonged in the patients group compared with the controls. Subjects with a QT dispersion longer than 50 ms (mean of the control ± 2 SD) were 18 cases in the patients group and one in the control group. During the follow-up period, patients died due to cardiac events in the patients group, whereas nobody in the control group. In patients with peripheral artery disease, a QT dispersion of 50 ms had 86% sensitivity, 57% specificity, 33% positive predictivity and 94% negative predictivity in predicting cardiac death. In 5 of the 7 patients who died during the study period, left ventricular dilatation and a QT dispersion langer than 50 ms had been detected. It is concluded that in patients with peripheral artery disease who are asymptomatic for cardiac diseases, echocardiographic findings and QT dispersion are useful methods to predict the risk of cardiac death.