Twenty-five-year-old woman with palpitations and hypertrophic cardiomyopathy

Clinical introduction A 25-year-old woman with a diagnosis of hypertrophic cardiomyopathy (HCM) and pre-excitation on ECG presented with unexplained syncope and daily palpitation. Genetic testing was positive for lysosome-associated membrane protein 2 (LAMP2) mutation which confirmed the diagnosis of Danon disease. Her younger sister was diagnosed with a similar condition and received a defibrillator implantation. Her 12-lead ECG (figure 1) and a long strip tracing (figure 2) are shown below. Question Where is the location of the accessory pathway and what is the next appropriate management? Anteroseptal pathway and catheter ablation Mid-septal pathway and pacemaker/defibrillator implantation Right lateral pathway and catheter ablation Fasciculoventricular pathway and electrophysiological study Left lateral pathway and electrophysiological study