Which of the following is not a cause of arrhythmias?

High cholesterol is associated with cardiovascular disease but does not directly cause arrhythmias in the same way that other conditions do. Arrhythmias are irregularities in the heartbeat that can result from various triggers affecting the electrical conduction system of the heart.

Coronary artery disease can lead to reduced blood flow to the heart muscle, potentially causing arrhythmias due to ischemia. Heart valve issues may disrupt the normal flow of blood through the heart, leading to changes in the heart's electrical activity. Hyperventilation can cause changes in the body’s chemistry that may affect heart rhythms, especially through its effects on carbon dioxide levels and acidity in the blood.

In contrast, while high cholesterol contributes to the development of atherosclerosis and coronary artery disease, it does not directly disturb the electrical pathways that control heartbeat regularity, making it less relevant as a direct cause of arrhythmias.