A pulse is the rhythmic throbbing felt in arteries, caused by the heart pumping blood through the circulatory system. Assessing a pulse is a fundamental way to gauge the heart’s activity and overall circulatory health, serving as a basic indicator of a person’s physiological state.
Understanding Central Pulses
Central pulses are located closer to the heart, directly reflecting its pumping efficiency. These include the carotid and femoral pulses, found in the torso. Peripheral pulses, such as those in the wrist (radial) or foot (dorsalis pedis), can diminish or disappear when blood pressure is low, such as during fainting or shock.
Because central pulses are less affected by low blood pressure, they are useful in emergency situations like cardiopulmonary resuscitation (CPR) or when assessing severe dehydration. The presence of a central pulse indicates the heart is still generating blood flow, even if peripheral circulation is compromised, providing immediate insight into circulatory status.
Key Locations for Central Pulses
The primary central pulse sites include the carotid arteries in the neck, the femoral arteries in the groin, and the apical pulse heard over the chest. The carotid pulse is located on either side of the neck, near the windpipe, just below the jawline. These arteries supply oxygenated blood directly from the heart to the brain.
The femoral pulse is found in the groin area, specifically in the crease where the thigh meets the abdomen, transporting oxygenated blood to the lower extremities. The apical pulse, also known as the point of maximal impulse (PMI), is located on the left side of the chest, usually at the fifth intercostal space at the midclavicular line in adults. This location corresponds to the bottom portion of the heart, allowing for a direct assessment of cardiac contractions.
Assessing Central Pulses
To assess the carotid pulse, a person should be sitting upright or lying at a slight angle. The examiner gently places the pads of their index and middle fingers on one side of the neck, between the windpipe and the large neck muscle. It is important to apply gentle pressure and never palpate both carotid arteries simultaneously, as this can reduce blood flow to the brain.
For the femoral pulse, the person should lie flat on their back. The examiner places their index and middle fingers midway between the pubic bone and the hip bone, just below the inguinal ligament. Firm, yet gentle, pressure is applied to feel the pulsation. The apical pulse is assessed using a stethoscope. The stethoscope’s diaphragm is placed over the fifth intercostal space at the left midclavicular line, and the heart sounds (“lub-dub”) are counted.
Interpreting Central Pulse Findings
Interpreting central pulse characteristics provides insights into cardiovascular health. The pulse rate, measured in beats per minute (bpm), ranges from 60 to 100 bpm in a resting adult. A pulse rate consistently above 100 bpm is termed tachycardia, which can be associated with conditions like anxiety, fever, infection, dehydration, or an overactive thyroid. Conversely, a rate below 60 bpm is called bradycardia, which may occur in athletes, during sleep, or indicate heart block or an underactive thyroid.
The rhythm of the pulse should be regular, with even intervals between beats. An irregular pulse suggests an arrhythmia, such as atrial fibrillation. The quality or strength of the pulse also conveys information. A “bounding” pulse, described as strong and forceful, can be found in states of increased blood volume or conditions like aortic regurgitation or hyperthyroidism. A “weak” or “thready” pulse, which feels faint and diminished, may indicate reduced blood volume or poor cardiac output, seen in conditions such as heart failure, shock, or severe dehydration. The complete absence of a central pulse is a medical emergency, often signaling cardiac arrest, where the heart has stopped pumping blood effectively.