Long-Term Frequency Gradients During Persistent Atrial Fibrillation in Sheep Are Associated With Stable Sources in the Left Atrium.

The article reports that in sheep, transition from paroxysmal to persistent atrial fibrillation (AF) presents continuous left atrial (la)-to-right atrial (RA) dominant frequency (DF) gradients in vivo accompanied by enlargement of the posterior LA. The researchers also tested the hypothesis that an LA-to-RA DF difference is linked with LA drivers in persistent AF. After AF was induced via RA tachypacing, electrograms were acquired from an RA lead and a loop recorder implanted near the LA.