Irregular narrow complex tachycardia misdiagnosed as atrial fibrillation

Dual atrioventricular (AV) node physiology may manifest with clinically significant tachycardia that is often misdiagnosed, sometimes with severe consequences.56 y/o female referred for atrial fibrillation (AF) ablation. She had a 3-year history of recurrent intermittent palpitations. 12-lead ECG