An unusual case of nonsustained ventricular tachycardia

A 54-year-old woman with advanced cirrhosis secondary to hepatitis C, end-stage kidney failure on hemodialysis, and nonischemic cardiomyopathy was admitted to the medical intensive care unit for treatment of a superior vena cava (SVC) thrombus involving a recently implanted cardioverter-defibrillator (ICD). During her hospitalization, the patient abruptly developed frequent ventricular ectopy with up to 20 beat runs of hemodynamically significant nonsustained ventricular tachycardia. Because ventricular ectopy was not previously seen in the patient, the sudden onset prompted a thorough evaluation. After other causes were excluded, a recently placed scopolamine patch was removed; the ventricular ectopy completely resolved within 24 hours and did not recur for the remainder of the patient's extended hospitalization. While anticholinergic syndrome is associated with a vagally mediated sinus tachycardia, ventricular arrhythmias have not previously been reported with scopolamine, to the best of the authors' knowledge. The observed cardiac side effects of scopolamine rarely occur at therapeutic doses. Scopolamine is metabolized primarily in the liver and excreted by the kidneys, so renal and hepatic impairment should be considered when initiating and dosing this medication. Because anticholinergic medications including scopolamine are commonly used in various clinical settings, we believe that clinicians should be aware of this significant but completely reversible adverse effect.