Variations in the Number of Pulmonary Veins Draining into Left Atrium and its Clinical Significance

Background : Pulmonary veins, normally two on each side bring oxygenated blood from lungs to left atrium. During early embryonic life, absorption of pulmonary venous network by the left primitive atrial chamber results in opening of four pulmonary veins which drain independently into its chamber. The extent of absorption and hence, the number of pulmonary veins which open into left atrium may vary. Objective : The study was done to observe the variation in the number of pulmonary veins opening in the left atrium. Materials and method : The present study was done on 30 formalin fixed hearts of unknown age and sex which were obtained from the department of anatomy, Government medical college, Chandigarh. These hearts were observed for the variations in pulmonary ostia on right and left sides and were compared on both sides and also with the earlier data. Results : In 8 (26.67%) out of these 30 hearts, variations were observed in the number of pulmonary veins and ostia either on one side or on both sides of the left atrium. 22 hearts (73.33%) out of 30 hearts had normal pulmonary veins which opened into left atrium via two separate pulmonary ostia, on either side. Conclusion : Knowledge of number of pulmonary veins and their ostia locations is important to ensure that all ostia are ablated, as ectopic foci may go untreated in variant veins.