Pattern of coronary arterial circulation and anastomoses in post mortem angiographic studies of human hearts.

Hearts from 131 unselected medicolegal autopsies have been studied. The age of the subjects ranged from 5 to 80 years old. After the coronary arteries were injected with radio opaque dye in gelatin the hearts were dissected and angiograms taken. Depending upon the pattern of coronary artery circulation, the hearts, were categorised into 3 groups. Group I or right preponderant heart was found in 63% of cases, group II or heart with 'balanced circulation' was present in 25% of cases while group III or 'left preponderant' heart was seen in 12% of the cases. This pattern of circulation is similar to that observed in the western population. Coronary collateral circulation was seen in all hearts, of all age groups. However, mild degree of anastomoses were common in the first three decades of life while in the later decades anastomoses were often marked. Hearts with grade III and IV coronary occlusions showed moderate to marked anastomoses in 70% of the cases. Myocardial scars were seen in 24 hearts. Of these, 22 had grade III and IV occlusions in their coronary arteries while, only 2 hearts had grade II occlusive lesions. The anastomoses were moderate to marked in 67% of these hearts.