Introduction: Corrected QT interval (QTc) has been demonstrated as a marker of sudden cardiac death (SCD). Cardiac magnetic resonance (CMR) has unique property to demonstrate myocardial fibrosis. The relationship of QTc with myocardial fibrosis and its territories has not been explored.
Methods: . 450 patients referring for delayed enhancement CMR were consecutively enrolled. Patients were categorized according to the presence of fibrosis. Electrocardiogram (ECG) was performed on the same day and QTc was analyzed.
Results: Mean age was 67+12 years and 58% were male. Myocardial fibrosis was present in 33.1%. The QTc was significantly longer in patients with fibrosis, compared to those without fibrosis (456 ms vs. 447 ms, p 0.02). Furthermore, QTc was significantly increased in the scar of RCA territory, but not in LAD or LCX territories. The association between each territory QTc and fibrosis was established.
Conclusions: This is the first to establish the correlation between QTc and myocardial fibrosis, particularly RCA territory. These findings may emphasis myocardial fibrosis using CMR as a potential risk of repolarization abnormally. The association between fibrosis and arrhythmia outcomes warrants further study.