What is a common cause of atrial fibrillation?

Increased atrial pressure or volume is a well-recognized trigger for atrial fibrillation. When there is an elevation in atrial pressure, it can lead to both structural and electrical changes in the atrial tissues. These changes promote the development of abnormal electrical conduction pathways and can result in the disorganized electrical activity characteristic of atrial fibrillation.

This is often seen in conditions such as heart failure, hypertension, and valvular heart disease, where remodeling of the atria occurs due to chronic volume overload or pressure overload. The distension of the atrial walls from increased volume can stretch the myocardium, leading to ectopic foci that initiate and sustain fibrillation.

Other options, while they may be associated with cardiac conditions, do not directly lead to atrial fibrillation in the same way. For instance, decreased heart rate is generally not a cause but rather is more commonly seen in bradyarrhythmic conditions. Hyperkalemia can affect cardiac function and may lead to other arrhythmias, but it is not a primary cause of atrial fibrillation. Similarly, coronary artery spasm can cause ischemic events and angina but does not directly result in atrial fibrillation. Understanding these nuances highlights why increased atr