Abstract
BACKGROUND: Atrial fibrillation (AF) typically affects the elderly persons. Personalized therapy for young patients needs to be considered. CASE SUMMARY: A 28-year-old young woman presented with recurrent palpitations for over 10 years and had previously received a diagnosis of "paroxysmal AF" elsewhere. She experienced recurrence postablation and poor drug response. A repeated electrophysiological study indicated multifocal atrial tachycardia, primarily 2 types originating from the sinus venosus, and successful ablation was performed. No atrial arrhythmias were observed during 6-month postoperative follow-up. The familial predisposition was genetically confirmed, with the patient carrying a pathogenic TNNI3K gene variant. DISCUSSION: This case was challenging because of unstable activation sequences. A sequential ablation strategy targeting individual morphologies was crucial. The strong family history underscored the role of genetic testing. TAKE-HOME MESSAGES: Cautious, nonempirical management is vital for young patients with "AF". Non-pulmonary vein, embryologically categorized AF triggers should be considered. Genetics can elucidate the underlying substrate.