All That Is Wide Is Not Ventricular Tachycardia: A Case Highlighting Supraventricular Tachycardia as an Alternative in Stable Wide Complex Tachycardia With Reversible Cardiomyopathy

Wide complex tachycardia (WCT) is often treated as ventricular tachycardia (VT). However, it can also be supraventricular tachycardia (SVT) with aberrant conduction, which is rarely life-threatening. Accurately differentiating VT from SVT with aberrancy guides appropriate therapy. We present a case that highlights the value of structured electrocardiogram (ECG) analysis in hemodynamically stable WCT and demonstrates reversible alcohol-related SVT-induced cardiomyopathy in a patient with familial susceptibility. A 51-year-old previously healthy woman presented to urgent care with four hours of palpitations and sharp substernal chest pain radiating to the right neck, accompanied by anxiety, nausea, and mild dyspnea. She had consumed alcohol heavily two days earlier and was hemodynamically stable. ECG showed a regular borderline WCT (QRS 114 milliseconds) at 192 beats per minute, flagged by machine interpretation as possible acute MI, prompting urgent transfer to the emergency department (ED). En route, she received IV amiodarone with resolution of symptoms. In the ED, repeat ECG revealed sinus WCT (QRS 121 milliseconds, at 105 beats per minute) with a left bundle branch block. Troponins and electrolytes were normal. Echocardiogram demonstrated a left ventricular ejection fraction (LVEF) of 22%. Invasive coronary angiography showed no obstructive disease. Cardiac MRI revealed no late gadolinium enhancement. She was started on full guideline-directed medical therapy (GDMT). Further history revealed prior vagal-responsive palpitations and a child with SVT requiring ablation. She was discharged with a 14-day ambulatory monitor showing SVT burden