Pulse

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.