THEODORE CHAN, MD, RICHARD A. HARRIGAN, M, and WILLIAM J. BRADY, MD
Dr Chan is professor of clinical medicine and medical director in the department of emergency medicine at the University of California, San Diego School of Medicine. Dr Harrigan is associate professor of emergency medicine at Temple University School of Medicine in Philadelphia. Dr Brady is associate professor of emergency medicine and internal medicine and vice chair of the department of emergency medicine at the University of Virginia School of Medicine in Charlottesville.
A 44-year-old man presents to the emergency department (ED) with light-headedness, nausea, and vomiting of 1 day's duration. He has also had intermittent palpitations but denies chest pain, dyspnea, and weakness. He also denies previous cardiac disease, cardiac risk factors, and a family history of heart disease. However, 6 months earlier he experienced an episode of syncope while walking; he did not seek medical attention for it.
His temperature is 36.2ºC (98.2ºF); heart rate, 225 beats per minute; respiration rate, 20 breaths per minute; and blood pressure, 96/49 mm Hg. Head, ears, eyes, nose, and throat are normal, and there is no evidence of jugular venous distention. His chest is clear symmetrically, and auscultation reveals a regular tachycardia with no gallops, rubs, or murmurs. Abdominal findings are normal, and his extremities show no cyanosis or edema. Because of the patient's nonspecific complaints and tachycardic pulse, an ECG is obtained (shown here).
Which of the following diagnoses is best supported by the ECG and clinical findings?
- Sinus tachycardia.
- Supraventricular tachycardia with aberrancy.
- Ventricular tachycardia or flutter.
- Atrial fibrillation.
- Atrioventricular (AV) nodal reentry tachycardia without aberrancy.
(Answer and discussion on next page.)
