What method is preferred for determining heart rate in an infant?

The apical pulse is the preferred method for determining heart rate in an infant because it allows for accurate measurement directly over the heart. In infants, the heart is relatively small and located more centrally in the chest, making it easier to assess the heartbeat effectively at the apex of the heart, typically found near the left fifth intercostal space, in the midclavicular line.

Using the apical pulse is particularly important in infants due to their high resting heart rates, which can range from 120 to 160 beats per minute, and the relatively small size of their peripheral pulses. This method is less susceptible to external factors that may affect peripheral pulse palpation, such as low blood pressure, dehydration, or vasoconstriction. Taking the apical pulse also allows for the assessment of rhythm and any irregularities that may occur, providing valuable data for clinical evaluation.

Other methods like the radial pulse, carotid pulse, or femoral pulse might be more challenging to assess in infants due to their smaller anatomy and higher heart rate, which can make those pulses difficult to palpate accurately. Hence, the apical pulse is recognized as the gold standard for heart rate measurement in this age group.