Anatomical analysis of the PV-LA junction revealed muscular discontinuities in 36% of segments and highly co-located adrenergic and cholinergic nerves, creating substrates for re-entry.
Observational (n=8)
OBJECTIVES: This study sought to examine the muscle connections and autonomic nerve distributions at the human pulmonary vein (PV)-left atrium (LA) junction. BACKGROUND: One approach to catheter ablation of atrial fibrillation (AF) is to isolate PV muscle sleeves from the LA. Elimination of vagal response further improves success rates. METHODS: We performed immunohistochemical staining on 192 circumferential venoatrial segments (32 veins) harvested from 8 autopsied human hearts using antibodies to tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT). RESULTS: Muscular discontinuities of widths 0.1 to 5.5 mm (1.1 +/- 1.0 mm) and abrupt 90 degrees changes in fiber orientation were found in 70 of 192 (36%) and 36 of 192 (19%) of PV-LA junctions, respectively. Although these anisotropic features were more common in the anterosuperior junction (p 50% of PV-LA segments, creating significant substrates for re-entry. Adrenergic and cholinergic nerves have highest densities within 5 mm of the PV-LA junction, but are highly co-located, indicating that it is impossible to selectively target either vagal or sympathetic nerves during ablation procedures.
Tan et al. (2006) conducted an observational in Atrial fibrillation (context) (n=8). Anatomical and immunohistochemical analysis of the PV-LA junction was evaluated on Muscular discontinuities and autonomic nerve distributions. Anatomical analysis of the PV-LA junction revealed muscular discontinuities in 36% of segments and highly co-located adrenergic and cholinergic nerves, creating substrates for re-entry.