Which condition does NOT predispose the heart to arrhythmias?

Increased physical activity does not typically predispose the heart to arrhythmias. While physical activity can elevate heart rate and modify cardiac function, it usually does not create an environment conducive to arrhythmias under normal circumstances. In fact, regular exercise and physical conditioning can strengthen the heart and improve its efficiency, often leading to a lower resting heart rate and better cardiovascular health.

On the other hand, electrolyte imbalances, certain drugs like digitalis, and hypoxia all create physiological conditions that disrupt normal cardiac electrical activity. Electrolyte imbalances can affect the conduction pathways in the heart, altering rhythm and potentially leading to arrhythmias. Digitalis, a medication often used to treat heart conditions, can have arrhythmogenic effects if not monitored properly. Hypoxia, or lack of oxygen, can impair cardiac function and lead to irregular rhythms as the heart struggles to maintain adequate oxygen supply to tissues. Each of these conditions directly impacts the electrical stability of the heart, making them more likely to result in arrhythmias.