Atrial Substrate Predicts Pulmonary Vein Isolation Success

In a study, published in the Journal of the American Heart Association, researchers sought to identify relationships between low-voltage zones (LVZs), transition zones, and atrial fibrillation in patients undergoing first pulmonary vein isolation (PVI). Based on prospective data, authors found LVZs had lower impact on outcomes in paroxysmal versus persistent atrial fibrillation, “suggesting that not all LVZs have equal prognostic implications,” they summarized.

This prospective multicenter study included 262 patients (31% female) with a mean age of 61 ± 11 years and either paroxysmal (n=130) or persistent (n=132) atrial fibrillation. Researchers assessed LVZs and transition zones on high-density electroanatomical maps obtained prior to PVI.

Atrial Substrate Features Correlate With PVI Outcomes

A total of 73 (28%) patients had recurrence at 28 months of follow-up. The researchers reported an extension of more than 5% and 15% LVZ in paroxysmal (hazard ratio [HR], 4.4; 95% CI, 2.0-9.8; P<.001) and persistent (HR, 1.9; 95% CI, 1.1-3.7; P=.04) atrial fibrillation, respectively, was associated with recurrence.

In addition, the authors found a significant association between LVZs and transition zones and (P<.001) LVZs and left atrial volume index (P<.001). Reportedly, 30% of patients had significantly increased left atrial volume index without LVZs, and 8% of patients had LVZs despite normal LAVI. Authors stated older age, female sex, oncological history, and increased atrial fibrillation recurrence were more common in the latter subgroup.

In closing, researchers noted “a proportional area of moderately decreased voltages accompanies LVZs, suggesting a continuous substrate instead of the dichotomous division of healthy or diseased tissue.”

They further summarized that “LAVI generally correlates with LVZs, but a small subgroup of patients may present with disproportionate atrial remodeling, despite normal LAVI.”

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