Case Presentation:

A 44–year–old man with no significant past medical history was admitted to the hospital for further evaluation of intermittent chest pain. He had no similar episodes in the past. He denied symptoms of dizziness, syncope or shortness of breath. His father had premature coronary artery disease. Otherwise, no history of arrhythmia or sudden cardiac death was reported in family. Physical exam, including vitals, was normal. Serial cardiac biomarkers and EKG were also normal. He underwent an exercise stress echocardiogram during which he felt lightheaded. His heart rate escalated from 160 beats per minute to 255 beats per minute. Corresponding EKG recording revealed a polymorphic ventricular tachycardia. The test was stopped and prompt return to normal sinus rhythm was noted on cessation of exercise. A trans–thoracic echocardiogram did not show any abnormality. His serum chemistry, including a magnesium level, was normal. Patient later underwent coronary artery catheterization, which was also unremarkable. He was started on oral beta–blocker therapy and remained asymptomatic until he was discharged home after 1 more day. A close follow up with cardiology, at discharge, was scheduled for evaluation for implantable cardioverter–defibrillator (ICD) placement.

Discussion:

Exercise stress test is commonly performed in the hospital. Very rarely, we may encounter young patients experiencing a fatal arrhythmia during testing. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is one such arrhythmia. It is a familial disorder, with mutation identified in two genes (RyR2 and CASQ2). Sporadic cases without family history may also be encountered. The estimated prevalence of CPVT is 1:10,000. It can be precipitated due to emotional or physical stress. Symptoms at presentation may vary from syncope or dizziness to sudden cardiac death. Affected individuals have a structurally normal heart and a normal baseline electrocardiogram. Diagnosis is clinical, based on positive family history and response to exercise or catecholamine infusion. Management involves avoidance of competitive sports, initiation of beta blocker therapy and most patients may ultimately require an ICD placement to avoid sudden cardiac death.

Conclusions:

Although CPVT is rarely encountered, physicians should be aware of this fatal arrhythmia. It can present in susceptible individuals undergoing a stress test. A careful personal and family history is important to suspect this disorder although sporadic cases can also manifest for the first time. Once diagnosed, it is important to initiate adequate treatment and proper counseling.