Scenario: A 48-year-old male triathlete applied for life insurance that required a 24-hour Holter study. Below are 2 rhythm strips in lead II; the top one was obtained at noon and the lower strip was obtained later in the afternoon at 6 PM. The athlete had no complaints.

The top strip shows sinus bradycardia at 37/min with an early repolarization pattern. The bottom strip indicates sinus bradycardia at 54/min with premature junctional contractions (PJCs).

Bradycardia is a heart rate slower than 60/min and is well characterized in athletes who may experience nocturnal bradycardia of less than 40/min due to parasympathetic tone. In addition, an early repolarization pattern is evidenced by the J wave at the end of the QRS complex. PJCs are premature depolarizations (contractions) originating from either the AV node or the His-Purkinje system. Because PJCs do not originate in the atria,...

You do not currently have access to this content.