In infants and children, what is the primary factor leading to cardiac arrest?

The primary factor leading to cardiac arrest in infants and children is severe hypoxia and bradycardia. In the pediatric population, the pathophysiology of cardiac arrest often differs from that in adults, where conditions like heart disease are more prevalent. Infants and young children are particularly susceptible to respiratory issues, and a significant decrease in oxygen levels (hypoxia) can quickly result in bradycardia, or a slow heart rate. This bradycardia can precede cardiac arrest and may occur as a compensatory mechanism in response to hypoxia.

When oxygen delivery to the heart and other vital organs is inadequate due to respiratory distress or obstruction, the body's compensatory responses are triggered. If the hypoxia is not addressed, the heart may slow down and eventually lead to cardiac arrest. Therefore, focusing on managing breathing and ensuring adequate oxygenation is critical when treating infants and children at risk for this outcome.

Other factors listed, such as chronic lung disease, electrolyte imbalance, and cardiomyopathy, can contribute to various health issues but are less common as primary direct causes of cardiac arrest in the pediatric population compared to severe hypoxia and bradycardia. These conditions may be considerations in the broader scope of care but do not represent the