Abstract

Background: Presence of an extra pulmonary ostium found in the left atrium during routine cadaveric dissection. Normally, four pulmonary veins (PV), two from each lung, return oxygenated blood to the left atrium (LA) and open into it through two pulmonary ostia, one on either side, since during embryonic development the primordial pulmonary vein and its principal branches merge with the atrial wall as the left atrium grows, giving rise to the four pulmonary veins. Structural variations can be observed by the degree of incorporation of the branches, thus affecting the number of openings in the left atrium. Clinically, pulmonary veins can trigger foci of electrical activity in atrial fibrillation, occasionally cause disorders like Total Anomalous Pulmonary Venous Return (TAPVR), cause abnormalities in electrical activity of the heart depending upon the number of pulmonary veins draining into the left atrium, and lead to perioperative bleeding during surgical and endoscopic procedures if the patient presents with unknown venous anatomy. Recent research has shown that about 36% of patients may have changes in pulmonary venous architecture, which could be the cause of ectopic cardiac activity. Method: Regular dissection was performed on an 80-year-old formalin-fixed female cadaver. The left atrium of the heart was studied externally to observe variation in pulmonary drainage pattern. The presence of an extra pulmonary ostium was seen on the left aspect of the left atrium. Tracing it towards the lung architecture showed the remnant structure in the root of the left lung, along with other openings, thus exhibiting one of the five different drainage variations explained in previous studies. Discussion: The number of pulmonary veins draining into the left atrium may range from one to five. In this cadaveric heart, one extra pulmonary vein was found between the left superior and inferior pulmonary veins. A common ostium is most frequently observed among the left-side, whereas an additional pulmonary vein is more commonly identified on the right side. In the cadaver though additional vein was found on the left side rather than the right. Conclusion: Knowledge of variations in the number and arrangement of pulmonary veins is clinically important, as the pulmonary veins are a major source of ectopic atrial electric activity thus of importance to cardiologists, radiologists and surgeons.

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