Coronary collateral circulation in the pig: correlation of collateral flow with coronary bed size

Abstract

Coronary bed sizes were measured in pigs. The left anterior descending bed occupies about 31% of the heart, the right coronary bed about 38% of the heart and the left circumflex bed about 31% of the heart is (including atria). The right coronary artery supplies about 81% of the right ventricle and 23% of the left ventricle with its blood supply. The remaining portion of the right ventricle is supplied by the LAD. The collateral circulation was measured in each of the 3 coronary beds using tracer microspheres. Measurements, are in ml/min/100 g. Transmural collateral flow in the LC is 5.6, the LAD 1.0, the RC in LV 3.7 and the RC in RV 4.3. Our experiments showed that the coronary bed sizes were relatively uniform in pigs, but that collateral flow was significantly different between the beds.

Ischemic cardiomyopathy in pigs with two-vessel occlusion and viable, chronically dysfunctional myocardium

“…Transition to hibernating myocardium occurred after 3-4 mo (average 107 days) and was accompanied by regional reductions in oxygen consumption (27) and flow (17,18). Although the LAD supplies ϳ40% of the pig left ventricle (35), LV ejection fraction in animals with hibernating myocardium and one-vessel occlusion was the same as sham-instrumented controls (17). In the present study, both the LAD and LC arteries were instrumented, thereby increasing the total LV mass at risk.…”

“…In the present study, both the LAD and LC arteries were instrumented, thereby increasing the total LV mass at risk. Based on previous measurements in pigs, we would estimate the risk area subjected to reversible ischemia to exceed 60% of the left ventricle (35).…”

Low zero-flow pressure and minimal capacitance effect on diastolic coronary arterial pressure-flow relationships during maximum vasodilation in swine.

“…19, 20 The LAD supplies about half of the left ventricular mass12 12 and the LAD vascular bed has a lower collateral flow compared with the circumflex and right coronary arterial vascular beds. 12 We elected to occlude the RCA because it supplies about the same mass of the left ventricle as the circumflex artery,12 13 and the RCA may be more likely to be the source of collateral flow to the LAD than the circumflex artery.2' Since the RCA and circumflex artery were not occluded simultaneously, we cannot exclude the possibility that there is some contribution of collateral flow to the distal LAD from the circumflex artery during RCA occlusion. The only way to exclude any possibility of collateral flow would have been to transiently occlude all three coronary vessels.…”

Effect of long-term exercise on regional myocardial function and coronary collateral development after gradual coronary artery occlusion in pigs.

“…The pigs' chests were closed, and the animals were allowed to recover. Experimental Protocol During a 4-week recovery period, the pigs were placed on the treadmill 1 In pigs with Konigsberg transducers, the ejection phase was defined as the time from peak left ventricular pressure rise (peak dP/dt) to 20 msec before peak negative dP/dt13 (Figure 1) or the corresponding points on the RT interval of the electrocardiographic trace. In a previous study from this laboratory,14 we established that the timing of systole could be determined by the electrocardiogram from epicardial electrocardiographic leads.…”