Objective To investigate effect of left vagal stimulation and autonomic nerve blockade on the electrophysiological properties of the left superior pulmonary veins (LSPV). Method In seven adult mongrel dogs, the effective refractory period (ERP) changed in the distal LSPV(LSPV-D), medial LSPV(LSPV-M) and proximal LSPV(LSPV-P) along with atrial fibrillation(AF) inducibility were studied in the baseline state, during left vagal trunk stimulating and in the present of autonomic blockade. Result The left vagal s...