What is indicated by a normal EKG tracing of a heart rate less than 60 beats per minute?

A normal EKG tracing of a heart rate less than 60 beats per minute indicates sinus bradycardia. In this situation, the heart rhythm originates from the sinoatrial (SA) node, maintaining a consistent pattern, but with a slower than normal rate. In adults, bradycardia is defined as a resting heart rate lower than 60 beats per minute.

Sinus bradycardia can be a normal physiological response, particularly in well-conditioned athletes or during sleep. It can also occur due to various medical conditions, medications, or in response to high vagal tone. The distinguishing factor is that the rhythm remains sinusoidal, meaning the regularity and morphology of the P waves and QRS complexes remain intact, while the heart rate indicates bradycardia.

Recognizing the characteristics of sinus bradycardia is essential for clinicians, as it helps determine if further evaluation or intervention is necessary based on the patient’s symptoms and clinical situation.