Pulse

The pulse is the rhythmic pressure wave felt in an artery with each heartbeat, caused by the surge of blood expelled from the left ventricle during systole. It can be felt at multiple sites on the body where arteries run close to the surface: the radial artery at the wrist, the carotid artery in the neck, the femoral artery in the groin, the brachial artery in the inner arm, and others.

The pulse provides several pieces of clinical information. Rate refers to the number of beats per minute: a normal adult resting rate is 60 to 100 bpm, below 60 is bradycardia, and above 100 is tachycardia. Rhythm indicates the regularity of the heartbeat: a regular pulse suggests normal sinus rhythm, while an irregularly irregular pulse (varying timing and strength from beat to beat) is characteristic of atrial fibrillation. Character and volume (the strength and quality of the pulse wave) indicate the state of cardiac output and peripheral circulation: a weak, thready pulse suggests reduced cardiac output, as seen in shock.

In cardiac arrest, cardiac output ceases and no pulse can be felt. Checking for a carotid pulse is part of the resuscitation algorithm to confirm cardiac arrest before commencing CPR, though this check should take no more than 10 seconds as an absent or uncertain pulse should prompt immediate initiation of CPR. During CPR, effective chest compressions can produce a detectable carotid pulse, and return of a spontaneous pulse (return of spontaneous circulation, or ROSC) is the goal of resuscitation.

Pulse oximetry (measuring blood oxygen saturation using a probe on the finger) also detects the pulse and is used continuously in critical care to monitor heart rate and oxygen levels.