Case Studies In Small Animal

Cardiovascular Medicine

Case 13

Coronary Artery Angiograms

Aortic root injection

The catheter has been advanced from the right carotid artery into the proximal ascending aorta where an injection of a radioiodinated contrast agent has been made. Only one coronary ostium can be seen with all of the coronary branches originating from it. The left anterior descending (LAD) coronary artery is the largest and descends down the front of the heart. The right coronary (RC) artery is seen as the most dorsal artery in this plane and is immediately below the label. It is normal. The left circumflex (LCx) coronary artery is fed by a small branch that appears to course ventrally and then horizontally. It is immediately above the label.

The catheter tip has now been placed selectively in the right coronary ostium and an injection of contrast agent made. All of the coronary artery branches fill simultaneously. The left anterior descending (LAD) coronary artery can again be seen originating from the right coronary ostium. The right coronary (RC) artery also originates from this ostium and is normal. The left circumflex coronary artery is fed by a small branch that appears to originate from the LAD and from a number of collateral vessels that also originate from the LAD. The upper small branch appears to wrap around a structure, which happens to be the area of the pulmonic valve or just ventral to it.

The only additional thing seen here is what appears to be a circle just caudal to the right coronary ostium. This frame was taken in systole so that the branch that feeds the left circumflex (LCx) coronary artery has moved dorsally (up) making it look like it connects to the right coronary (RC) artery. This is an illusion but does make it look like these arteries are encircling the pulmonic valve region. LAD - left anterior descending

Video clip of aortic root angiogram

Contrast agent was injected into the root of the aorta. Only one coronary ostium leading to a large coronary artery can be seen on the ventral border of the aortic root. The large artery is the left anterior descending coronary artery. Two smaller arteries can be seen coursing backward. The upper one is the right and the bottom one is the left circumflex. The left circumflex initially goes ventrally and then courses caudally. The bend it takes as it goes from coursing ventrally to coursing caudally occurs as it goes around the region of the pulmonic valve.

Video clip of a selective injection of contrast agent into the right coronary ostium

Contrast agent was injected selectively into the right coronary ostium (ventral aspect of aortic root). Similar to the aortic root injection, the contrast first flows into the large left anterior descending coronary artery. It can then be seen coursing around the pulmonic valve region (encircles it) to turn again into the left circumflex coronary artery (lower) and right coronary artery (upper). At the very end you can see contrast (faintly) coming back into the great cardiac vein, immediately above the right coronary artery.