Effects Of Autonomic Nerves System On Paroxysmal Atrial Fibrillation Originating From The Pulmonary Veins

Objective Atrial fibrillation is the most common arrhythmia in clinic, and more than 90% of foci are located within pulmonary veins. The mechanism of atrial fibrillation is not clear, and autonomic nerves system maybe involves it. This study set up a animal model of paroxysmal atrial fibrillation and investigate effect of left vagal stimulation and autonomic nerve blockade on the electrophysiological properties of the pulmonary veins, which would show how the autonomic nerve blockade contribute to atrial fibrillation.Method Twenty adult mongrel dogs was divided to two groups . The effective refractory period (ERP) changed in distant (-D), medial (-M) and proximal (-P) parts of the left superior pulmonary veins(LSPV), left inferior pulmonary veins (LIPV), right superior pulmonary veins (RSPV) and right inferior pulmonary veins (RIPV) along with atrial fibrillation inducibility were studied in the baseline state, during left vagal trunk stimulating and in the present of autonomic blockade.Result: 1) A model of focal atrial fibrillation originating from the pulmonary veins was accomplished in eighteen dogs. The inducibility of atrial fibrillation is 29.58% as S₁S₁ stimulating; 2) Under the baseline state, the ERP of LSPV-P is shorter than LSPV-D(106.7±9.4 vs 118.3±13.0 ms, P<0.05). There is no significant difference during the left vagal stimulating and vagal blocking, while the ERP of LSPV-P is longer than LSPV-D(151.7±11.2 vs 136.1±7.8 ms, P<0.05) in presence of atropine and propranolol. The ERP in distant and proximal parts of LIPV, RSPV and RIPV is no difference expect that the ERP of RSPV-M is...