Coronary arteriography in dogs following blunt cardiac trauma: a longitudinal assessment

The purpose of the study was to examine the effects of blunt cardiac trauma on the epicardial coronary arteries of dogs by using sequential coronary arteriographic studies. A direct impact to the anterior surface of the heart at a velocity of 12 m/sec was delivered by an air pressurized impactor in eight of ten dogs with the chest open and the pericardium intact. Selective coronary arteriograms were performed percutaneously with the chest closed starting just before trauma and repeated afterward at intervals of 3 hours, 3 days, 2 weeks, and 5 weeks. Two of ten dogs were sham operated and did not undergo impact to the heart. The coronary arteries in these two dogs remained angiographically normal throughout the study period. In dogs that underwent impact and were maintained for the entire duration of the study (seven of eight dogs), injury to the epicardial coronary arteries occurred in every instance. Injury was limited mostly to branches of the left anterior descending and right coronary arteries. The left circumflex coronary artery, which was posterior to the site of impact, was always spared. The types of injury included complete branch occlusion, partial coronary obstruction, extravasation, and in one instance, an arteriovenous fistula. In nearly all instances, these injuries became evident angiographically between 3 hours and 3 days after impact and usually were completely resolved after 2 to 5 weeks. These observations indicate that the epicardial coronary arteries may be compromised by nonpenetrating cardiac impact. The resulting coronary pathology, however, resolved within a few weeks after injury.