Distinctive electrophysiological properties of pulmonary veins in patients with atrial fibrillation

Atrial fibrillation (AF) is frequently initiated from pulmonary veins (PVs), but little is known of the electrophysiological properties of PVs. Two groups were studied: 28 patients (49+/-13 years old) with paroxysmal AF and 20 control patients (49+/-14 years old) without AF. Effective and functional refractory period and conduction time from PV to left atrium (LA) were compared in the 2 groups by use of programmed stimulation with a single extrastimulus in the PVs and LA. In the AF group, the venous effective refractory periods (ERPs) were shorter than that of the LA: 185+/-71 versus 253+/-21 ms, P