Content Reviewers:Lisa Miklush, PhD, RNC, CNS, Janine Eagon MS, APNP, CNS, RNC-OB
Contributors:Aileen Lin, MScBMC, Jennifer Montague, PhD, Rachel Yancey, Bianca Mancas, RN, Kelsey LaFayette, DNP, ARNP, FNP-C, Paige Randall, MS, RN, CNE, CEN
Every time the heart beats, it creates a pulse that sends blood into the arteries throughout the body, delivering oxygen and nutrients to organs and tissues. When assessing your patient’s pulse, you are evaluating their general cardiovascular health, while following the steps of the Clinical Judgment Measurement Model or CJMM to make clinical decisions about patient care.
Okay, let’s review the physiology of a pulse, which is a pressure wave that’s generated when the left ventricle contracts. This creates a palpable pulse as blood is pushed through the arterial system. You can assess your patient’s pulse centrally by auscultating the apical pulse over the apex of the heart at the point of maximal impulse and counting the beats for a full minute.
Normally, the apical pulse has two sounds: S1, or lub, and S2, or dub. Both S1 and S2 are produced when certain heart valves close in response to heart muscle contraction. You can also assess a pulse distally, using your second and third fingers to lightly palpate over peripheral pulse sites, most commonly the radial artery.
Now, the pulse is an indirect measure of cardiac output, which is the amount of blood the heart pumps in one minute. When you take your patient’s pulse, you’ll be assessing the rate, rhythm, and amplitude. When the pulse is faster than normal, it’s called tachycardia. With tachycardia the heart has less time to fill with blood, so there’s less blood pumped out with each heartbeat, reducing cardiac output. On the flipside, if the heart rate is too slow, it’s called bradycardia. With bradycardia, cardiac output is also reduced, since blood isn’t pumped out fast enough to meet the needs of the body.
Your patient’s pulse should also be regular. An irregular pulse, or arrhythmia, can be caused by electrolyte imbalances or certain types of heart disease, and can affect cardiac output by decreasing cardiac filling time or impairing contraction of the ventricles. Likewise, an expected finding is a pulse that can be felt with your fingers while applying moderate pressure. A weak, thready pulse is associated with decreased cardiac output, whereas a full, bounding pulse can be associated with increased cardiac output.
Alright, when assessing a patient’s pulse, you’ll use the Clinical Judgment Measurement Model to gather and recognize important cues. In addition to the pulse rate, you will recognize other objective cues associated with alterations in pulse, like an irregular rhythm, weak, thready pulse, as well as subjective cues like dizziness, palpitations, chest pain, or shortness of breath. You will also recognize other factors like anxiety, stress, pain, fever, and hypoxia, as well as certain medications that can speed up the pulse, like bronchodilators or slow down the pulse, like beta blockers. Additionally, the pulse rate tends to decrease with age and during sleep.