Transient changes in P-wave terminal force after electrical cardioversion of persistent atrial fibrillation

BACKGROUND: P-wave terminal force in lead V1 (PWTFV1) reflects left atrial remodeling and is associated with atrial fibrillation (AF) outcomes, but its time course after electrical cardioversion of persistent AF is unclear. METHODS: We retrospectively analyzed 108 patients with persistent AF after successful electrical cardioversion, with 12‑lead electrocardiograms at 30 min, 1 month, and 3 months. Terminal P-wave duration (PNTV1) and amplitude (PNAV1) in lead V1 were measured and PWTFV1 calculated as their product; changes are expressed in absolute magnitude. Correlations with left atrial diameter and categorical classification (abnormal if magnitude ≥4000 ms·μV) were assessed. RESULTS: PNTV1 increased at 1 month versus 30 min (60 ± 25 vs 58 ± 19 ms; P = 0.018) and returned to baseline at 3 months (57 ± 19 ms; P = 0.83; Friedman P = 0.031). PNAV1 was unchanged (P = 0.37). PWTFV1 increased transiently in magnitude at 1 month (-4294 ± 2545 vs -4079 ± 2138 ms·μV; P = 0.022) and normalized at 3 months (-4039 ± 2060 ms·μV; P = 0.64). PWTFV1 did not correlate with left atrial diameter (all |ρ| ≈ 0.05, P ≥ 0.61), and categorical classification was unchanged (57/108 abnormal throughout; no patient reclassified). CONCLUSION: PWTFV1 shows transient, duration-driven variability after cardioversion, peaking at 1 month. The change is small, does not alter categorical classification, and is not mirrored by left atrial size, consistent with ongoing atrial recovery rather than stable remodeling. Timing of assessment matters when PWTFV1 is interpreted as a continuous measure.