Successful catheter ablation of ventricular fibrillation storm in acute myocardial infarction by eliminating triggering premature ventricular contraction at the remote site from the exit

Figure 1. A: Electrocardiograms and intracardiac electrograms of the triggering premature ventricular contraction (PVC) before catheter ablation. The earliest Purkinje potential preceded the QRS onset by 150 ms. Fluoroscopy shows the location of a multielectrode linear mapping catheter placed along the left ventricle (LV) posterior septum. B: Activation map of the triggering PVC before catheter ablation. The PVC exit was located at the apical LV posterior septum. LAO = left anterior oblique; LAT = local activation time; RAO = right anterior oblique.

Figure 2. A: Twelve-lead electrocardiogram and intracardiac electrograms of the triggering premature ventricular contraction (PVC) at the first radiofrequency application site. The Purkinje potential preceded the triggering PVC by 170 ms. B: Twelve-lead electrocardiogram and intracardiac electrograms of the triggering PVC after 14 catheter ablation applications. The triggering PVC was preceded by a chevron pattern in the distal His–left posterior fascicle–Purkinje activation, with the earliest site preceding the QRS onset by 180 ms. Fluoroscopy shows the location of the multielectrode linear mapping catheters. ABL = ablation catheter; H = His potential; His = His catheter; LAO = left anterior oblique; LV = left ventricle; RAO = right anterior oblique.

Figure 3. A: Twelve-lead electrocardiogram and intracardiac electrograms of the triggering premature ventricular contraction (PVC) at the successful radiofrequency (RF) application site. The Purkinje potential preceded the triggering PVC by 270 ms at the left anterior fascicle (LAF) region where RF application eliminated the PVCs. This abnormal potential could only be recorded before the PVC. B: The bipolar voltage map of the left ventricle (LV). The successful ablation site was located at the scar border zone in the voltage map. C: Schematic of the proposed PVC circuit. The PVC originated from Purkinje fiber at the basal anterior LV septum, and the impulse retrogradely came into the proximal left posterior fascicle (LPF), traveled via the damaged Purkinje network in the LPF region, and broke out to the apical LV posterior septum while retrogradely activating the His bundle. The yellow dotted line and arrows indicate the presumed pathways that trigger the PVC. Red tags indicate all RF application sites. ABL = ablation catheter; Bi = bipolar voltage map; His = His catheter; LAO = left anterior oblique; RAO = right anterior oblique.