The Relationship between Coronary Artery Aneurysm and QT Interval Dispersion in Acute Phase of Kawasaki Disease

OBJECTIVE QT dispersion (QTd) has been proposed as a marker of ventricular repolarization inhomogeneity and several investigations have proved the relationship between it and cardiac ischemia, ventricular arrhythmia and sudden cardiac death. The aim of this study was to assess the relation between coronary artery involvement and QTd, and QTc dispersion (QTcd) in the acute phase of Kawasaki disease (KD). METHODS We studied 65 patients with acute KD. Patients were divided into 3 groups. Group one consisted of 48 patients without coronary artery involvement. Group two comprised 13 patients with small to medium size aneurysm. In Group three there were 4 patients with giant aneurysm or multiple small to medium size aneurysms or thrombosis in coronary arteries. For each patient 12 lead electrocardiography was obtained, and QT, QTc, QTd, QTcd, and RR interval were calculated. FINDINGS There were 40 males and 25 females with a mean age of 41.4±31.1 months. There was no significant difference in QT, QTc, RR measurements between 3 groups. QTd was greater in group 3 versus group 1 and 2, but the difference was not statistically significant (P=0.06). QTcd was significantly greater in group 3 than in groups 1 and 2 (75.02±11.53 ms versus 46.82±15.39 ms and 48.88±10. 55 ms respectively (P = 0.04). The sensitivity of QTcd ≥60 ms to detect the patients with severe coronary arteries involvement was 100%, the specificity was 93.4%, positive predictive value was 50%, negative predictive value was 100%, and accuracy was 93.8%. CONCLUSION QTcd can be used as a predictive factor for diagnosis of severe coronary arteries involvement in the acute phase of KD.