A middle-aged man with a medical history of hypertension developed sudden-onset palpitations and chest pain while watching television. Emergency medical services diagnosed the patient with supraventricular tachycardia (SVT) and administered adenosine, which terminated the tachyarrhythmia. The patient’s chest pain also abated promptly with the resolution of the SVT, and the patient denied any further symptoms. The patient was taken to the emergency department (ED), where electrocardiographic findings demonstrated normal sinus rhythm without any ST-deviation. The patient remained asymptomatic and denied exertional and nonexertional chest discomfort or dyspnea prior to the episode.

The emergency physician performed a physical examination and ordered laboratory tests, which yielded normal results except for an elevated troponin I level of 1.82 ng/mL. A cardiologist was consulted, and the patient agreed to admission to the coronary care unit for further management. The repeated troponin I testing at 6 hours later revealed that the level had increased to 5.95 ng/mL, but the patient remained asymptomatic.