What is the correct method for assessing the heart rate of a four-month-old infant?

The method for assessing the heart rate of a four-month-old infant is to auscultate for 60 seconds. This approach is specifically important for young infants because their heart rates can vary significantly. Auscultation allows for a more precise measurement by counting the beats directly through a stethoscope over a full minute. This is particularly important in infants, as their heart rates tend to be higher and can fluctuate due to various factors such as activity level, body temperature, and crying.

Measuring the heart rate over a full minute also helps to account for any irregularities that may occur in a shorter timeframe. While palpating the pulse can be done, it may not be as accurate at this age due to the small size and rapid variability of an infant's heart rate. Therefore, auscultating for a full 60 seconds is the most reliable method for obtaining an accurate heart rate in a four-month-old infant.