24.14: Pulse
When the heart pumps blood out, arterial elastic fibers play a crucial role in sustaining a high-pressure gradient. They expand to accommodate the received blood and then recoil - a process known as the pulse that can be either manually palpated or electronically quantified. Despite a reduction in its effect with increased distance from the heart, elements of the pulse's systolic and diastolic components persist, observable even at the arteriole level.
The pulse serves as a clinical indicator of a patient's health status, documented in terms of beats per minute. Both the pulse rate and its strength bear significant clinical value. A high or irregular pulse rate could be a result of physical exertion or other transient factors, but it might also signal a cardiac condition. The strength of the pulse reflects the power of ventricular contraction and cardiac output. A robust pulse implies high systolic pressure, whereas a weak pulse suggests a decline in systolic pressure, potentially necessitating medical intervention.
To manually palpate the pulse, one places the fingertips lightly across a superficial artery. This procedure is typically performed using the radial artery in the wrist or the common carotid artery in the neck, although any palpable superficial artery may be utilized. Frequent pulse sites include the temporal and facial arteries in the head, brachial arteries in the upper arm, femoral arteries in the thigh, popliteal arteries behind the knees, posterior tibial arteries near the medial tarsal regions, and dorsalis pedis arteries in the feet. Additionally, an assortment of commercial electronic devices are accessible for pulse measurement.
Beyond merely indicating heart rate, evaluation of pulse can provide a wealth of information about a patient's health. A rapid or irregular pulse may signify a cardiac disorder such as arrhythmia, or it could be a symptom of conditions such as anxiety, dehydration, or fever. Pulsus paradoxus, a notable decrease in pulse strength during inspiration, could indicate pericardial effusion or severe asthma. A bounding pulse, on the other hand, might suggest aortic valve insufficiency or hyperthyroidism. The absence of a pulse in a peripheral artery could imply arterial occlusion and is considered a medical emergency. Therefore, pulse assessment forms a vital part of clinical examinations, aiding in early detection and diagnosis of numerous health conditions.
