Which cardiac chamber diameter best predicts maintenance of sinus rhythm after successful cardioversion in atrial fibrillation?

Which cardiac chamber diameter best predicts maintenance of sinus rhythm after successful cardioversion in atrial fibrillation?

• A. Right ventricle
• B. Left ventricle
• C. Left atrium
• D. Right atrium

Answer: (C)

In atrial fibrillation, structural remodeling of the atria, especially the left atrium, drives the arrhythmia and its persistence. The left atrium enlarges over time due to ongoing irregular rhythm and hemodynamic stress, and this enlargement is associated with fibrosis and electrical heterogeneity that create a substrate for reentry and AF maintenance. After successful cardioversion, patients with a larger left atrium have a higher chance of AF returning because the atrial substrate for sustaining sinus rhythm remains unfavorable. The other chambers are less directly tied to the atrial remodeling process that sustains AF, so their sizes are not as predictive of whether sinus rhythm will be maintained. Although left atrial volume measurements are often used and are even more informative than simple diameter, the left atrial size in general best predicts maintenance of sinus rhythm after cardioversion.

In atrial fibrillation, structural remodeling of the atria, especially the left atrium, drives the arrhythmia and its persistence. The left atrium enlarges over time due to ongoing irregular rhythm and hemodynamic stress, and this enlargement is associated with fibrosis and electrical heterogeneity that create a substrate for reentry and AF maintenance. After successful cardioversion, patients with a larger left atrium have a higher chance of AF returning because the atrial substrate for sustaining sinus rhythm remains unfavorable. The other chambers are less directly tied to the atrial remodeling process that sustains AF, so their sizes are not as predictive of whether sinus rhythm will be maintained. Although left atrial volume measurements are often used and are even more informative than simple diameter, the left atrial size in general best predicts maintenance of sinus rhythm after cardioversion.