What is the primary condition that leads to atrial fibrillation (AFib)?

Atrial fibrillation (AFib) is commonly associated with structural and electrical changes in the heart, particularly in the atria. Left atrial enlargement is a key factor contributing to the development of AFib. When the left atrium is enlarged, often due to chronic conditions that lead to increased left atrial pressure, it creates an environment that is conducive to the initiation and maintenance of AFib.

This enlargement typically occurs in response to conditions like hypertension, mitral valve disease, or other factors that chronically increase the workload on the heart. As the left atrium stretches, the electrical conduction pathways become disrupted, leading to abnormal rhythms such as AFib. Understanding this mechanism emphasizes the importance of addressing underlying conditions that can lead to left atrial enlargement, which can, in turn, help prevent the onset of atrial fibrillation.

While conditions such as mitral valve stenosis, coronary artery disease, and heart failure can contribute to AFib and affect the overall cardiac function, they often do so by promoting left atrial enlargement or directly impacting the heart’s structure and electrical activity. However, the primary condition specifically recognized for initiating changes that lead to AFib is chronic left atrial enlargement.