INTRACORONARY DOPPLER FLOW VELOCITY-MEASUREMENTS IN 2 PATIENTS WITH SOLITARY CORONARY OSTIUM - IS THERE TRUE OBSTRUCTION

Background Coronary anomalies in the absence of other major cardiac ma lformations are rare, with an incidence of less than 1-1.5%. Although most have been incidental findings without clinical relevance, a subgr oup of anomalies has been identified that are associated with cardiac symptoms or even sudden cardiac death. This subgroup includes an ectop ic origin and abnormal course of the left coronary artery from the rig ht sinus of Valsalva. Results We examined two patients with this anoma ly. In patient I the left main coronary artery took a deep intramural course anterior to the pulmonary trunk, and in patient II the left ant erior descending coronary artery took its course between the pulmonary trunk and ascending aorta. Both anomalies were identified by coronary angiography and that in patient I was confirmed by surgery. Intracoro nary Doppler flow velocity measurements during cardiac catheterization , including atrial pacing in patient II, demonstrated significant flow acceleration in both patients. This occurred within the intramural se gment (in patient I) and in the segment between the pulmonary artery a nd ascending aorta (in patient II). Conclusions These findings indicat e that external Vessel compression is one pathophysiological mechanism that leads to ischaemia and a longstanding history of cardiac symptom s in these patients. Invasive haemodynamic measurements such as these have not previously been available.