Cardiac arrest can occur due to which of the following conditions besides a blockage of blood vessels?

Cardiac arrest can indeed occur due to drowning because this situation leads to a lack of oxygen being supplied to the body, particularly the heart and brain. When a person is submerged in water, they may experience asphyxiation, which can quickly lead to cardiac arrest due to the heart not receiving the necessary oxygen. This is a critical aspect of first aid and emergency response, as recognizing the signs of drowning and the subsequent risks is vital in performing effective CPR and resuscitation.

While breathing emergencies, excessive fatigue, and high blood pressure can also lead to serious health concerns, they operate in different mechanisms compared to drowning. Breathing emergencies primarily affect the lungs but do not necessarily lead to immediate cardiac arrest if oxygenation is restored. Excessive fatigue might contribute to cardiac events over time, but it is not an immediate cause. High blood pressure poses a risk for heart disease, but again, it doesn't directly cause the heart to stop beating in the acute sense like drowning does. Thus, among these options, drowning is the condition most directly associated with causing cardiac arrest through a lack of oxygen.