Mitral Valve Stenosis and the Most Common Arrhythmias: Understanding Atrial Fibrillation

Among the various cardiac complications associated with rheumatic heart disease, mitral valve stenosis often leads to a range of atrial arrhythmias. These rhythm disturbances typically begin with premature atrial contractions and can progress to more severe conditions such as atrial tachycardia, atrial flutter, and eventually paroxysmal or chronic atrial fibrillation.

Why Atrial Arrhythmias Develop in Mitral Stenosis

The primary cause of these rhythm abnormalities lies in the structural changes brought on by mitral valve narrowing. As the valve orifice decreases in size, blood flow from the left atrium to the left ventricle during diastole becomes restricted. This obstruction leads to increased pressure within the left atrium, prompting the chamber to dilate in an attempt to compensate.

Structural and Functional Changes Leading to Atrial Fibrillation

In addition to mechanical stress, chronic inflammation from rheumatic fever contributes to fibrosis of the atrial wall. This fibrotic change disrupts normal electrical conduction pathways in the atrium, creating an environment conducive to the development of atrial fibrillation (AFib).

The Impact of Atrial Fibrillation on Heart Function

Once atrial fibrillation develops, it can significantly impair cardiac performance. The loss of coordinated atrial contraction reduces ventricular filling efficiency, which in turn lowers cardiac output. This decline in heart function can worsen symptoms of heart failure, increase the risk of thromboembolic events, and reduce overall quality of life.

Managing atrial fibrillation in the context of mitral stenosis is crucial for preventing further complications. Treatment strategies often include rate or rhythm control, anticoagulation therapy, and in some cases, interventional or surgical valve repair or replacement.