Confusion, Ataxia, and Wide-Complex Tachycardia: What Caused This Arrhythmia?

Abstract

A previously healthy 36-year-old woman presented at the emergency department with gradual-onset confusion, ataxia, and aphasia. Her vital signs were normal. On physical examination, she reacted to painful stimuli but was nonverbal and unable to follow commands. Initial laboratory results revealed no abnormalities. Computed tomograms of the head and results of a lumbar puncture were nondiagnostic. During hospitalization, the patient decompensated and needed emergency intubation and vasopressor support. An electrocardiogram (ECG) was obtained ( Fig. 1). An echocardiogram revealed an acute reduction of left ventricular ejection fraction (range, 0.35-0.40) and anterior wall-motion abnormalities. Notable laboratory results included troponin I, 17.1 ng/mL; normal thyroid values; and negative toxicology screening. Which of the following diagnoses explains the ECG?A) Supraventricular tachycardia with aberrant conduction B) Bidirectional ventricular tachycardia C) Drug toxicity D) Accelerated junctional rhythm