The Heavy Heart: An Unusual Cause of Ventricular Tachycardia

Abstract

A 17-year-old female presented to the emergency department with a one-hour history of abdominal pain, nausea, vomiting and weakness. Physical examination on admission revealed a heart rate of 106 beats per minute, blood pressure of 136/88 mmHg and a respiratory rate of 25 breaths per minute. Her medical history was unremarkable with no prior medical comorbidities or surgical history. She denied taking any prescribed or over the counter medications. The initial ECG showed ventricular tachycardia (VT) (Figure 1), with investigations revealing a normal troponin I level of <0.03ng/ml (reference range <0.3 ng/mL), elevated N-terminal pro-brain natriuretic peptide level of 439.2 ng/L (reference range <300 ng/L) and normal serum potassium level of 4.0 mmol/L (reference range 3.5-5.3 mmol/L). Over the next hours, the patient developed shallow respirations, with rapid worsening of muscle weakness involving all four limbs. An arterial blood gas obtained on room air revealed severe acidosis (pH, 7.178) and hypoxemia (PaO2, 65.8 mmHg). A repeated blood test conducted four hours after admission noted profound hypokalemia (serum potassium, 1.9 mmol/L).