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ECGs in the ED.

CASE A 13-year-old boy presents to the Emergency Department complaining of a sustained episode of palpitations following soccer practice. The episode started abruptly and resolved gradually with rest. This was the first time he recalls having that kind of symptom. There has been no chest pain, shortness of breath, dizziness, or syncope. He denies headache, nausea, or vomiting. He normally has no exercise intolerance. The past medical history is noncontributory. There have been no prior hospitalizations or surgeries. He takes no medications and has no known drug allergies. The family history is noncontributory for congenital heart disease, arrhythmia, or sudden death. He attends eighth grade and lives with both parents and a healthy brother. There are no known ill contacts. In the Emergency Department, the patient is acyanotic and in no distress. He is alert and interactive. The temperature is 37.2-C. The heart rate is 74 bpm and the respiratory rate is 18 per minute. The blood pressure is 112/68. There are moist mucous membranes. There is no jugular venous distension. The chest is clear to auscultation. The cardiac exam has a normally active precordium with a regularly irregular rhythm. There is a normal first heart sound and a soft, physiologically splitting second heart sound. There is no gallop. There is a II/VI vibratory systolic ejection murmur heard especially on the post-extrasystolic beats. The pulses are full and equal. The abdomen is soft and nontender without organomegaly. The extremities are warm and well-perfused. An electrocardiogram was performed while the patient complained of another sustained episode of palpitations in the Emergency Department (Fig. 1).