BRANCHING PATTERNS IN CORONARY-ARTERY AND ISCHEMIC AREAS INDUCED BY CORONARY ARTERIAL-OCCLUSION IN THE CLAWN MINIATURE PIG

This study of 28 CLA WN miniature pigs (male 17, female 11, mean weigh t 29 kg) was undertaken to investigate the coronary arterial branching patterns and the ischemic area induced by surgical occlusion of the l eft anterior descending artery (LAD) and change in the ischemic area o ver time. These results were compared with those in dogs, which have f requently been used in myocardial ischemic research. Regarding the cor onary arterial branching pattern, there were fewer ventricular branche s from the right and left coronary arteries than in dogs. The septal b ranches arose from only the LAD and the posterior descending artery (P D). The largest septal artery branched from the LAD. There were two ty pes of septal artery branching patterns. In approximately 80% of the C LA WN miniature pigs, the PD arose from the right coronary artery (Rig ht dominance). The peculiarity of the coronary arterial branching patt ern in the CLA WN miniature pigs was more similar to human beings than to dogs. The ischemic area induced by occlusion at three-fifths dista l section of the LAD was 12.1% to 22.6% (mean 17.1%) of the left ventr icle. The ischemic area in all animals that died of global left ventri cular malfunction and hemodynamic instability after LAD occlusion was more than 25% of the left ventricle.