When assessing a 4-month-old male infant's heart rate, which action is correct?

Auscultating the heart rate at the 4th intercostal space for 60 seconds is the correct approach for assessing an infant's heart rate. This area is located where the heart is best heard, providing an accurate measurement of the heart's sounds and rhythm. For infants, a thorough assessment often involves counting the heart rate for a full minute to account for any fluctuations and ensure an accurate reading, especially given their higher and variable heart rates compared to older children and adults.

In clinical practice, listening to the heart over the appropriate intercostal space allows the examiner to hear the heart sounds clearly. For infants, the 4th intercostal space aligns with the anatomical location of the heart, facilitating effective auscultation.

Alternative methods, such as palpating pulses in other areas, may not provide as reliable or comprehensive a measurement in infants. The brachial pulse can also be used but is typically an adjunct method rather than the primary means of assessing heart rate. Additionally, while the radial pulse can be assessed in older children and adults, it is not the best option for infants because it is less palpable due to their smaller size.