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Impact of right pulmonary vein anatomical variations on the phrenic nerve trajectory and pulmonary vein isolation strategy: Preprocedural imaging and 3D mapping insights

Year: 2025

Type: article

Abstract: BACKGROUND: Predicting phrenic nerve (PN) location based on right pulmonary vein (RPV) anatomy using preablation imaging may help avoid PN injury. OBJECTIVE: The purpose of this study was to determine the relationship between RPV anatomical variations and PN trajectory. METHODS: One hundred three consecutive patients who underwent preablation computed tomography or magnetic resonance imaging had RPV anatomy identified as typical with separate right superior PV (RSPV) and right inferior PV (RIPV) showing distal branching vs right middle PV (RMPV) or early branching of the RSPV. PN location was identified using high-output pacing (50 mA × 2 ms) over 3 contiguous RPV ostial and paraseptal antral zones: RSPV, RPV carina, and RIPV. The relationship between anatomical variations and the PN trajectory, with the need to adjust planned ablation lines to more distal antral position (greater than additional 10 mm from the ostium), was determined. RESULTS: Early branching of the RSPV occurred in 24%, and an RMPV was present in 21% with anatomical variations more frequent in women (65% vs 38%; P=.01). PN capture extending to the RIPV antrum was significantly more common in patients with an RMPV (59.1%; prevalence ratio [PR] 10.3; 95% confidence interval [CI] 2.5-43.2) or early branching of the RSPV (64%; PR 10.9; 95% CI 2.7-44) compared to typical anatomy (3.6%). Antral ablation line adjustments to avoid PN injury were required in 28% of patients, more frequently in those with an RMPV (50%; PR 5.6; 95% CI 2-15.7) or early branching (56%; PR 5.2; 95% CI 1.3-15.3) compared to typical anatomy (7.1%). CONCLUSION: RMPV or early branching of the RSPV increases the likelihood of PN capture in the RIPV proximal antrum by 10-fold and requires a more distal antral ablation line to avoid phrenic nerve injury.

Source: Heart Rhythm

DOI: 10.1016/j.hrthm.2025.02.033