B-PO04-153 SUBTLE REPOLARIZATION ABNORMALITIES IN IDIOPATHIC VENTRICULAR FIBRILLATION ARE UNCOVERED BY NONINVASIVE ELECTROCARDIOGRAPHIC IMAGING, BUT NOT THE 12-LEAD ELECTROCARDIOGRAM

Sudden cardiac arrest is most often due to ventricular fibrillation (VF). When no cause found during diagnostic follow-up, classified as idiopathic VF. We hypothesize that subtle repolarization abnormalities may predispose VF, but cannot be detected from the 12-lead electrocardiogram (ECG). To study presence of time (RT) gradients in patients with VF using ECG and noninvasive electrocardiographic imaging (ECGI). In control individuals without cardiovascular disease survivors we manually determined heart-rate corrected QT interval (QTc) peak-to-end T wave (Tp-Te) ECG. ECGI was performed a custom-made setup noninvasively map RT isochrones on epicardium determine maximum local gradient (RTG). included 10 11 (iVF). Figure 1 shows both QTc Tp-Te did not differ between these groups. However, uncovered steeper compared controls (P=0.03). Noninvasive ECGI, standard ECG, can uncover Steeper could play role induction through unidirectional conduction block. improve mechanistic understanding risk assessment apparently