What happens to heart rate during primary apnoea?

During primary apnoea, the heart rate typically falls due to the lack of adequate ventilation and subsequent oxygen deprivation. This stage occurs when a newborn is not breathing effectively, leading to a decrease in oxygen levels in the blood. The body's response to this hypoxic state is to initially attempt to compensate, but as the level of oxygen declines further, the heart rate drops.

Blood pressure usually remains relatively stable during this initial response because the body is activating compensatory mechanisms to maintain perfusion to vital organs despite drops in heart rate. Therefore, the observation that heart rate falls while blood pressure does not change is accurate for primary apnoea. This underscores the significance of recognizing the state of the newborn and the physiological responses that occur during these critical moments.