Close Call From a Sweet Twist: A Case of Licorice-Induced Torsades De Pointes

Abstract

Torsades de pointes (TdP) is a life-threatening cardiac arrhythmia that can result from QT interval prolongation, sometimes secondary to medication adverse effects and electrolyte derangements. We present a 95-year-old Hispanic male with advanced chronic kidney disease (CKD) that was evaluated for dizziness and progressive weakness. The diagnosis of severe symptomatic hypokalemia and QT prolongation was made, and the patient was admitted for telemetry monitoring and aggressive intravenous electrolyte replacements. While under observation, the patient experienced syncope due to ventricular tachycardia (VT) with episodes of torsades de pointes. Due to refractory potassium depletion and hypertension, workup for hyperaldosteronism revealed renal potassium wasting, inappropriately normal plasma renin levels, and almost undetectable aldosterone levels. Careful analysis revealed the excessive chronic daily ingestion of licorice-containing candy twists and tea, which may cause pseudohyperaldosteronism. Licorice is a commonly used natural product that is available in many forms. It is sometimes used as a natural supplement and as a sweetener that can be widely found in many food products. Excessive ingestion can lead to apparent mineralocorticoid excess, reduced plasma potassium, sodium retention, hypertension, and metabolic alkalosis. Hypokalemia can be severe in some patients and lead to fatal cardiac arrhythmias such as ventricular tachycardia and torsades de pointes. Careful analysis is essential in cases of refractive hypokalemia and renal potassium wasting, especially in elderly patients with underlying renovascular disease.

Keywords: hypokalemia; licorice; other causes of hypokalemia; pseudohyperaldosteronism; qt prolongation; refractory hypokalemia; resistant hypertension; secondary hypertension; supplements; torsades de pointes (tdp).

Figure 1. Baseline and arrival ECG

(A) The patient’s baseline ECG without QT interval prolongation and with an averaged QT/QTc of 403/434 ms and post-premature ventricular contraction (PVC) QT of 400 ms. (B) Admission ECG with evidence of frequent premature ventricular contractions (PVCs) in bigeminy pattern, T-wave flattening, and prolonged QT intervals averaged at 534 ms and post-PVC at 580 ms Adm, admission; ECG, electrocardiogram; QTc, corrected QT

Figure 2. Torsades de pointes and licorice candy twists

(A) ECG trace obtained during polymorphic ventricular tachycardia on the cardiac telemetry, with evidence of torsades de pointes (TdP) and the characteristic twisting of peaks. (B) The illustration shows chewy ropes of candy licorice twists as a common source of licorice and hence the metaphoric title of “Close Call From a Sweet Twist,” referring to the licorice-provoked TdP aVR, augmented vector right; aVL, augmented vector left; aVF, augmented vector foot; ECG, electrocardiogram