SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The role of coronary collateral circulation in limiting ischemia and infarction has been studied prospectively. Transient occlusion of a coronary artery angioplasty has provided evidence that collateral circulation decreases wall motion abnormalities, ST segment changes, and lactate production. Patients who have collateral flow also have a better outcome after coronary artery dissection and acute closure than patients without collateral flow. Collateral circulation also limits infarct size during acute myocardial infarction with and without thrombolysis. Although collateral flow may decrease coronary artery bypass graft patency in certain subgroups of patients, the perioperative infarct rate and mortality is decreased. Growth factors have been identified that increase the development collateral circulation and may improve ventricular function in the setting of myocardial infarction.
The coronary collateral circulation of 162 patients suffering from atherosclerosis and coronary insufficiency (coronary artery disease) was studied. It was found to be present in 44 patients, or 27.1%; homocoronary in 9%, intercoronary in 90.9%. As other Authors have previously reported, anastomotic circulation is more developed when the coronary occlusion exceeds 75%. Not one of the 44 cases with normal coronary arteries or occlusion inferior to 75% presented collateral circulation. In addition, it was found to be present more frequently in cases with three branch lesions. The time of insurgence of coronary insufficiency seems to condition the development of anastomotic circulation which appears more frequently when the symptoms have been present for more than 5 years (43.9%). Anastomotic circulation is also found more frequently (48.4%) in patients who have suffered myocardial infarction and who have angina. Collateral circulation was not found in any of the 46 patients with unstable isolated angina; this seems to show the importance, in its pathogenesis, of the functional factor (spasm). In conclusion, we may say that anastomotic circulation is more developed: 1) in cases of severe occlusive lesions (in severe coronary occlusive disease/atherosclerosis) (85%);2) in three branch lesions; 3) in cases of long standing symptomatology; 4) in stable angina and in angina t infarction.
BACKGROUND AND HYPOTHESIS: Although it is well established that diabetes mellitus (DM) induces more severe coronary artery disease (CAD), it is not known whether it contributes to the development of coronary collateral circulation. The present study examines coronary collateral circulation in diabetic and nondiabetic patients with angiographically verified CAD. METHODS: The study group consisted of 463 diabetic patients (382 men, 81 women) with a mean age of 60.3 +/- 8.8 years, and 227 nondiabetic subjects (159 men, 68 women) with a mean age of 59.2 +/- 9 years. The extension and functional capacity of coronary collateral circulation was assessed according to the Cohen and Rentrop grading system of 0 to III. RESULTS: We found that diabetic patients had grade III collateral circulation more frequently than nondiabetic subjects (13.2 vs. 8.5%, p < 0.01). This finding was even more pronounced in diabetic men aged < 55 years compared with both nondiabetic men (20 vs. 3.4%, p < 0.001) and diabetic women (20 vs. 2.2%, p < 0.001). Grade III collateral circulation was found to develop mainly at the left anterior descending (LAD) coronary artery and the right coronary artery (RCA), where complete occlusions of coronary arteries usually occur. CONCLUSIONS: Diabetic patients with CAD develop more extensive coronary collateral circulation than nondiabetic subjects, especially men aged < 55 years. The collateral circulation mainly develops at the LAD and RCA.
The collateral circulation in the rat small intestine was studied by evaluating the viability of an intestinal segment after its primary mesenteric vascular supply had been interrupted. After ligation of the main mesenteric branches of a 30-cm segment of either jejunum or ileum, viability was assessed immediately by the fluorescence pattern observed under ultraviolet illumination after the peripheral intravenous injection of sodium fluorescein. Viability was assessed again at 48 hours by the fluorescein technique and by gross and histologic examination. With the marginal vessels intact, the collateral circulation was able to sustain 10 per cent of the entire length of small intestine beyond the point of devascularization. On the other hand, when the marginal vessels had been ligated, this length of sustained intestine proved to be negligible. With respect to the above findings, there was no difference in the extent or pattern of collateral circulation at different levels along the small intestine, from proximal jejunum to jejuno-ileal junction to terminal ileum. Systemic infusion of a vasodilator, isoproterenol, was found to substantially decrease the length of small intestine maintained viable by collateral flow. This was associated with a greater decrease in systemic vascular resistance than in mesenteric vascular resistance, which resulted in a drop in mesenteric blood flow. In each of the above studies, the ultimate viability of the intestine by histologic section at 48 hours correlated closely with the fluorescein pattern immediately after devascularization. These studies demonstrate that the collateral circulation of the small intestine is extensive and sufficient to maintain viability in a substantial proportion of the length of the entire intestine.(ABSTRACT TRUNCATED AT 250 WORDS)
The extent and functional capacity of coronary collateral circulation in patients with systemic hypertension has not been elucidated. In the present study, 313 patients with coronary artery disease were studied to evaluate coronary collateral circulation in relation to the presence of systemic hypertension and left ventricular hypertrophy. Patients had greater than or equal to 95% diameter luminal obstruction of either the left anterior descending or the right coronary artery. Patients were classified into 2 groups: The hypertensive group consisted of 61 patients, mean age 55 +/- 9 years, with systemic hypertension, and the normotensive group consisted of 252 patients, mean age 53 +/- 8 years, without hypertension. The hypertensive group had more severe angina pectoris and less history of healed myocardial infarction than the normotensive group (p less than 0.001). Left ventricular wall thickness was 1.26 +/- 0.1 cm in the hypertensive and 1.03 +/- 0.06 cm in the normotensive group (p less than 0.001). The hypertensive group had more extensive coronary collateral circulation than the normotensive group (p less than 0.01). There was a positive relation between coronary collateral circulation and left ventricular wall thickness (p less than 0.001). These results indicate that patients with systemic hypertension and coronary artery disease have an increase in coronary collateral circulation corresponding to the degree of left ventricular wall thickness.