Cardioversion of pre-excited atrial fibrillation leading to ventricular fibrillation- case report and review of literature.

Pre-excited, fast conducting atrial fibrillation (AF) is a serious life-threatening arrhythmia that requires urgent pharmacological or electrical cardioversion. When anti-arrhythmic medications fail to restore sinus rhythm, biphasic, direct current (DC) cardioversion is required. Appropriate synchronization of the DC shock with the QRS is crucial, however not easily achieved. Since the QRS-T complexes in pre-excited AF are severely distorted, the diagnosis of inaccurate synchronization may be overlooked. Here, we report a unique case where during electrical cardioversion of pre-excited AF with inappropriate synchronization on the T wave inadvertently resulted in ventricular fibrillation (VF), and review the literature.