What clinical sign might suggest heart failure in a newborn?

A clinical sign that suggests heart failure in a newborn is an irregular heart rhythm. In newborns, heart failure can manifest as changes in cardiac function, which can lead to arrhythmias, or irregularities in heart rhythm. This can occur due to various underlying conditions, including structural heart problems or volume overload.

An irregular heart rhythm may be accompanied by other signs such as poor feeding, lethargy, or respiratory distress. Early identification of these cardiac issues is crucial to managing potential heart failure and preventing further complications.

The other options do not provide significant indicators of heart failure. A normal respiratory rate can be misleading, as newborns can sometimes maintain normal rates even while having underlying cardiac issues. Stable blood pressure is also not a reliable indicator alone, as newborns can present with heart failure even with normal blood pressure readings. Consistent temperature readings do not correlate with cardiac function and thus are not relevant in identifying signs of heart failure.