[Anatomic variation of the aortic coronary openings (apropos of 80 dissections)].

A series of 80 heart dissections, compared with a survey of the literature shows that:--both coronary ostia are usually in the right anterior and in the left posterior position, in the commissural plane, at the level of the corresponding sinus of Valsalva (the left one being often superior in size to the right one).--anatomic variations of the coronary ostia (especially variations of the left coronary ostium) may be summed up into 3 patterns: Variations in number : sometimes, there is only one aortic coronary ostium, usually owing to a left coronary artery originating from the pulmonary artery; a common aortic ostium for a single coronary artery is not frequent. Multiple ostia are the most common variations : an accessory artery may arise from a separate ostium (often the "third coronary artery" from the right aortic sinus; sometimes the anterior descending and the circumflex arteries may originate from separated orifices). Variations in origin remain few, affecting most often the left ostium. Variations in size reflect the corresponding coronary plexus preponderance.