Resumen:
BACKGROUND Electrophysiological studies in patients with atrial fibrillation demonstrated the presence of etectrical conduction between superior and inferior left pulmonary veins (PVs) that makes electrical disconnection of individual PVs difficult. Anatomically, the prevalence, sizes, and locations of the interpulmonary connections have not been investigated systematically. METHODS We retrieved 112 PVs from 28 patients who died from noncardiac causes (43 +/- 13 years, 17 mates). Dissections of subepicardial myocardial strands at the venoatrial junctions were made in 10 hearts, and histological sections were made in the remaining 18 hearts. RESULTS We found histological variations in the muscular width of the interpulmonary isthmus between ipsilateral left and right PVs (2.7 +/- 0.5 mm vs 1.7 +/- 0.5 mm; P < .05). Histologic sections of 15 hearts revealed myocardial strands 0.2-3.5 mm thick crossing obliquely at the Left isthmus in 53%, at the right isthmus in 33%, and at both isthmuses in 14% of hearts to connect with the myocardial sleeves of adjacent veins. In 40% of hearts there were additional direct bridges connecting the anterior or posterior watts of the veins. The crossing myocardial str...