How many beats per minute is considered within the normal range for sinus rhythm?

A normal sinus rhythm is characterized by a specific range of heart rates, which typically lies between 60 and 100 beats per minute. This range is important because it indicates that the heart is functioning properly and following the electrical conduction pathways established by the sinoatrial (SA) node. The SA node is the natural pacemaker of the heart that initiates each heartbeat at a regular pace.

When heart rates fall below 60 beats per minute, it is referred to as bradycardia, which can suggest that the heart is either too slow or that there is an underlying condition affecting heart activity. Conversely, a rate exceeding 100 beats per minute can be classified as tachycardia, indicating that the heart is racing, which might be due to stress, activity, or a medical condition.

These distinctions emphasize the significance of maintaining a heart rate within the 60-100 beats per minute range to ensure effective circulation and adequate oxygen delivery throughout the body. This understanding provides a foundational context for assessing heart rhythm in various clinical scenarios in nuclear medicine and general healthcare.