Heart Rate Thresholds and Definitions

Normal Adult Pulse Rate and Bradycardia

The American Heart Association defines a normal resting pulse rate as 60-100 beats per minute, with bradycardia defined as <60 bpm and tachycardia as >100 bpm, though clinically significant bradycardia typically occurs at <50 bpm and more appropriate thresholds may be 50-90 bpm for normal sinus rhythm 1, 2
Bradycardia is formally defined as a heart rate <60 beats per minute, but this technical definition does not always indicate pathology 1, 2
Clinically significant bradycardia that causes symptoms typically occurs at heart rates <50 beats per minute, which is the working definition used in emergency cardiac care 1, 2, 3, 4
Treatment should focus on whether the bradycardia is causing symptoms, not just on the heart rate number alone 1, 2
Asymptomatic or minimally symptomatic patients do not necessarily require treatment unless the rhythm is likely to progress to become life-threatening 1, 2

Tachycardia is often a compensatory response to underlying conditions rather than a primary problem requiring rate control 5, 6
Treatment must be directed toward identifying and treating the underlying cause, not directly slowing the heart rate with medications 5, 6
Rate-controlling medications can precipitate cardiovascular collapse when tachycardia is compensatory for hypotension or maintaining cardiac output 6