The apical pulse represents the actual beating of the heart, heard or felt directly over the heart’s apex. It provides a precise indicator of heart rate and rhythm, reflecting the contractions of the left ventricle as it pumps oxygenated blood into the aorta. This direct assessment of heart function distinguishes it from peripheral pulses, such as those felt at the wrist or neck, which are pressure waves traveling through arteries. The apical pulse offers valuable insights into cardiac health.
Locating the Apical Pulse
To find the apical pulse in adults, the specific anatomical landmark is the fifth intercostal space at the midclavicular line on the left side of the chest. The midclavicular line is an imaginary vertical line that extends downwards from the middle of the collarbone. The intercostal spaces are the spaces between the ribs.
To locate this precise spot, begin by feeling for the sternal notch at the top of the breastbone, then moving down to the Angle of Louis, which corresponds to the second rib. Counting downwards from the second intercostal space, the fifth intercostal space is typically found just below the nipple on the left side for most adults. For infants and young children, the apical pulse is generally located at the fourth intercostal space at the left midclavicular line.
When attempting to feel or listen for the apical pulse, the patient should ideally be in a supine (lying flat on their back) or seated position. If using a stethoscope, place the diaphragm directly on the bare skin at the identified location. In individuals with larger breasts, it may be helpful to ask them to gently reposition breast tissue to expose the area.
Expect to hear a clear “lub-dub” sound when listening with a stethoscope. This “lub-dub” represents one cardiac cycle, with “lub” corresponding to the closure of the atrioventricular valves (S1) and “dub” to the closure of the semilunar valves (S2).
Measuring the Apical Pulse
Accurately measuring the apical pulse requires a stethoscope and a watch with a second hand or a digital timer. Before placing the stethoscope on the patient’s chest, warm the diaphragm by holding it in your palm for a few seconds to prevent startling the patient.
Ensure the patient is positioned comfortably, with their chest exposed for direct stethoscope placement. Place the diaphragm of the stethoscope firmly over the point of maximal impulse (PMI), the previously located fifth intercostal space at the midclavicular line.
Once heart sounds are heard, count each “lub-dub” as one beat. For accuracy, especially if the heart rhythm appears irregular or if the patient is taking cardiac medications, count the beats for a full 60 seconds. If the rhythm is regular, counting for 30 seconds and multiplying by two can provide an accurate rate.
Note the total number of beats per minute and observe the regularity of the rhythm. A normal resting heart rate for adults ranges from 60 to 100 beats per minute. Record the apical pulse rate, noting if the rhythm was regular or irregular, and any other observations.
Understanding Its Importance
Checking the apical pulse is often preferred in scenarios where peripheral pulses are difficult to assess. This includes infants and young children, where radial pulses can be challenging to palpate. Similarly, in obese individuals, peripheral pulses may be obscured by tissue, making the apical pulse a more reliable option.
The apical pulse provides a more accurate assessment of heart function, particularly in individuals with cardiac conditions like arrhythmias, where heart contractions may not consistently produce a palpable peripheral pulse. An irregular apical pulse can indicate underlying conditions such as atrial fibrillation or heart valve disease.
Monitoring the apical pulse is also valuable for patients on specific cardiac medications, such as digoxin or beta-blockers, as it helps assess the medication’s effect on heart rate and rhythm. It offers direct insight into the heart’s mechanical activity, ensuring a precise evaluation of cardiovascular status.