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PubMedDate not supplied

[Coronary collateral circulation: its importance and significance in ischemic cardiopathy].

With the purpose of studying coronary collateral circulation and if it has influence in manifestations, complications, prognosis and mortality in patients with ischemic heart disease, we studied 52 patients, 41 male and 11 female, mean age 56 years, who died. All of them had a complete medical record and were seen with regularity until death. They had good quality coronaragraphy and ventriculography. Post-mortem study was done in all of them. They were placed in two groups: group I (27 patients) who had adequate collateral circulation and group II (25 patients) without adequate collateral circulation. We found that group I patients had angina more frequently prior to myocardial infarction (p less than 0.005) with greater duration (30 months). Complications during the acute phase of myocardial infarction were more common in patients without collateral circulation (p less than 0.001). Although we did not find statistically significant differences, we could observe that patients without adequate collateral circulation have less survival, disturbances in ventricular wall mo-motion are more frequently found and there is more incidence of sudden death. There was no significant difference between the apparition of myocardial infarction in patients with or without adequate coronary collateral circulation. Diabetic patients had less collateral circulation than non diabetics (p less than 0.05). We conclude that the protective role of collateral circulation in ischemic heart disease is established, diminishing complications during acute myocardial infarction and providing for longer survival.

Adult↗
PubMedDate not supplied

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

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.

Animals↗
PubMed1986

The response of the coronary collateral circulation to acute administration of nifedipine: an angiographic and ergometric study.

To evaluate the role of collaterals in patients with effort angina we retrospectively compared the coronary cineangiograms of 14 subjects ("responders") who improved their exercise tolerance after acute nifedipine therapy with 14 subjects ("non-responders") with the same symptomatology who did not respond to the same treatment. The status of collaterals was graded with a score from a minimum of 0 to a maximum of 5. The responders showed a greater score than the non-responders (3 +/- 1 vs. 1 +/- 1, P less than 0.001), whereas there was no difference in the number of stenosed vessels between the two groups (1.8 +/- 0.9 vs. 2 +/- 0.8). Thus, in patients with effort angina and critical coronary stenosis, the presence of an efficient coronary collateral circulation can favour the increase in coronary flow reserve after vasodilator therapy. Our results suggest that the grading of collaterals may add useful information to the simple classification of one-, two- or three-vessel coronary artery disease.

Adult↗
PubMed1976

Comparison of the coronary collateral circulation in dogs and baboons after coronary occlusion.

The relevance to man of experimental observations on coronary collateral blood flow (CCBF) in dogs has been questioned. The effect of 2 to 3 hour coronary occlusions in the anesthetized dog and a primate, the baboon, were therefore compared, with CCBF measured by injections of 85Kr distal to occlusion with precordial counting. Before killing, additional isotope was infused to compare inner/outer wall flow distribution and myocardial tissue samples were analyzed for electrolyte content. Effects of nitrates on hemodynamics and metabolism were also compared in dog and baboon. Similar values for CCBF and resistance following occlusions were found in dog and baboon (flow approximately 25 per cent control, calculated resistance increase four- to sevenfold). Greater subendocardial ischemia in both species was indicated by isotope distribution less to the inner wall, but electrolyte changes (k+ less and Na+ greater in the ischemic area compared to nonischemic) were similar transmurally in both species. Hemodynamic responses to nitrate infusion (isosorbide dinitrate) were similar, with increase in CCBF and decrease in resistance. In neither group were inner/outer wall isotope distribution or electrolyte changes influenced by nitrate. The coronary collateral response to occlusion is similar in dog and baboon in terms of both hemodynamics and metabolic changes. After 2 to 3 hours of coronary occlusion some hemodynamic benefit may be demonstrated with nitrates but no metabolic advantage, at least in the central area of ischemia.

Animals↗
PubMed2004

[Formation and function of coronary collateral circulation and their influencing factors].

OBJECTIVE: To clarify the formation and function of coronary collateral circulation (CCC) in coronary artery disease (CAD) patients with severe coronary artery stenosis and their influencing factors. METHODS: Coronary angiography was performed on 266 CAD patients with severe coronary stenosis. CCC formation was evaluated by Rentrop rating on those 266 patients and 401 severe stenosis arteries; while in CCC formed patients, CCC function was evaluated by Werner collateral collection (CC) rating. The formation, function of CCC and their influencing factors were analyzed and compared. RESULTS: CCC formation in those severe stenosis coronary arteries was related to the severity of coronary stenosis: the forming rate of CCC was 42.6% in vessels with 90%-94% stenosis (Group A), 56.9% with 95%-99% stenosis (Group B) and 93.0% with 100% stenosis (Group C) (p <0 .01). Between CCC forming and non-forming groups, there was no significant difference in age, gender, incidence of MI, hypertension and diabetes, history of smoking and serum levels of HDL-C and LDL-C (P > 0.05). In the CCC formation group, serum HDL-C level was the highest in the CC Grade 2 group (according to Werner function rating) and the lowest in the CC Grade 0 group (P < 0.05). Whereas, LDL-C level was the lowest in the CC Grade 2 group and the highest in the CC Grade 0 group (P < 0.05). CONCLUSION: Severity of coronary stenosis was the major influencing factor in CCC formation and function, and the rate of CCC formation increased with the exacerbation of coronary stenosis. Serum HDL-C and LDL-C level had no relationship with CCC formation, but related to CCC function. Better CCC function was found in patients with high level of HDL-C whereas the patients with high level of LDL-C had spoiled CCC function.

Cholesterol, HDL↗
PubMed2006

Coronary collateral circulation: the effects of smoking and alcohol.

OBJECTIVE: The presence or absence of coronary collaterals is of vital importance during acute ischemia. Smoking and alcohol have been suggested to play a role, but data are scarce. We examined the extent to which smoking and alcohol use affect the presence of coronary collateral circulation. METHODS: Cross-sectional study in 242 patients, admitted for elective PTCA. Smoking was defined as past or current. Pack years were calculated and categorized into never-smokers (reference-category): <10, 10-19, 20-29, and >or=30 pack years. Alcohol consumption was defined as past or current, and categorized into never-users (reference-category): <1, 1-10, 11-20, and >or=21 units per week (UPW). Collaterals were graded with Rentrop's classification. Coronary collateral presence was defined as Rentrop-grade >or=1. RESULTS: Current smoking (odds ratio (OR) 4.17; 95% confidence interval (CI) 1.79-9.71) was positively associated, while pack years of smoking was not related. Current alcohol intake showed a J-shaped tendency with coronary collateral presence, while past moderate alcohol consumption was inversely associated (OR 0.19; 95% CI 0.04-0.98). CONCLUSIONS: Smoking and (to some extent) alcohol use are associated with collateral presence. The results support the view that life-style factors may affect the formation of coronary collaterals in patients with ischemic cardiac disease.

Aged↗
PubMed1991

Effects of nitroglycerin and diltiazem on well-developed coronary collateral circulation in conscious dogs.

The purpose of the present study was to compare the effects of nitroglycerin and diltiazem on coronary collateral circulation. Studies were conducted in 8 conscious dogs instrumented for the measurement of left circumflex coronary artery (LCCA) flow, subendocardial segment lengths in areas perfused by the LCCA, and left anterior descending coronary artery (LAD). Brief, repeated LCCA occlusions sufficiently developed collateral vessels for the resting metabolic requirement in the LCCA region. One week following the cessation of repeated LCCA occlusions, two-minute coronary occlusions with and without drug pretreatment were performed on separate days. The ischemic responses to coronary occlusions were not altered by diltiazem (50 micrograms/kg, IV), but nitroglycerin (5 micrograms/kg, IV) attenuated myocardial ischemia definitely. The authors conclude that nitroglycerin produces greater effects than diltiazem in attenuating myocardial ischemia in the collateral dependent zone when effects of each drug on systemic and coronary circulation were minimized by pretreatment with small doses.

Animals↗
PubMed1999

Effect of Salvia Miltiorrhiza on coronary collateral circulation in dogs with experimental acute myocardial infarction.

To evaluate the effect of Salvia Miltiorrhiza on coronary collateral circulation in dogs with experimental acute myocardial infarction, 12 dogs were randomly divided into Salvia Miltiorrhiza group (group D) and control group (group C). Acute myocardial infarction model was established in all dogs, Salvia Miltiorrhiza or saline was administered to the 2 groups respectively for 21 days. Coronary angiography was performed before and after ligation of coronary artery. The capillaries and distribution vessel density in tissue sections of myocardia were assessed. Angiography 2 h and 22 days after ligation of coronary artery revealed significant augmentation of collateral vessels, and capillaries and distribution vessel density in ischemic zone on day 22 showed statistically significant augmentation in group D as compared with that of controls (P < 0.05 and P < 0.01). It is concluded that Salvia Miltiorrhiza might improve the opening and formation of coronary collateral circulation of ischemic myocardia in dogs and thereby protecting myocardia from ischemia.

Animals↗
PubMed2000

Quantitatively assessed coronary collateral circulation and restenosis following percutaneous revascularization.

AIMS: A high degree of collateral supply to a vascular area where a percutaneous transluminal coronary angioplasty (PTCA) has been performed represents a haemodynamic force competing with the antegrade flow through the dilated lesion. Therefore, our purpose was to determine whether patients with restenosis following PTCA have a higher collateral flow to the recipient vessel than patients without restenosis. METHODS AND RESULTS: In 200 consecutive PTCA patients, an intracoronary pressure-derived collateral flow index (CFI) was determined quantitatively during balloon occlusion, using simultaneous measurements of the mean aortic pressure (P(ao)) and of the intracoronary pressure distal to the occluded stenosis (P(occl)), as well as the estimated central venous pressure (CVP=5 mmHg): CFI=(P(occl)-CVP)/(P(ao)-CVP). Sixty-four patients had an angiographic follow-up examination after at least 2 months, and were subdivided into patients with restenosis (>50% diameter stenosis, n=34) and patients without restenosis (n=30). Patients with restenosis had a significantly higher collateral flow index at the initial coronary angiography than patients without restenosis (0.26 +/- 0.14 vs 0.12 +/- 0.09; P<0.0001). CONCLUSIONS: Patients with restenosis after PTCA show a more extended collateral supply to this recipient area than patients without restenosis. Well developed collaterals to a revascularized region are a risk factor for restenosis of the treated lesion.

Adult↗
PubMed1991

Exercise training and coronary collateral circulation.

This review examines the potential for an exercise-induced increase in coronary collateral circulation, with specific reference to the role and functional significance of collateral vessels, highlighting animal and human studies in particular, and their inherent methodological limitations. Exercise training may enhance myocardial oxygen supply by promoting transient periods of myocardial ischemia, a potent trigger of collateral growth. Some human studies have shown that moderate-to-high intensity training can result in a higher double product at the onset of angina and/or ischemic ST-segment depression, suggesting that myocardial oxygen supply has increased. Attempts to use thallium-201 exercise scintigraphy to assess myocardial perfusion before and after a physical training program have produced conflicting data, whereas angiographic studies in group trials have, without exception, yielded disappointing results. Thus, direct evidence that exercise stimulates collateralization in humans is lacking.

Animals↗
PubMed1999

[Effect of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction].

OBJECTIVE: To evaluate the effect and mechanism of puerarin on coronary collateral circulation in dogs with experimental acute myocardial infarction. METHOD: Twelve dogs were randomly divided into puerarin (Gegen su, G) group and control(C) group, the acute myocardial infarction model was built in all dogs. Puerarin or saline was administered for 21 days. Coronary angiography was performed before and after ligating coronary artery. The capillaries and distribution vessel density in tissue sections of myocardium were assessed. RESULT: Angiography on hour 2 and day 22 after ligating coronary artery revealed significant augmentation of collateral vessels in G group versus controls. Capillaries and distribution vessel density in ischemic and infarctive zone on day 22 revealed statistically significant augmentation in G group versus controls (P < 0.05 and P < 0.01). CONCLUSION: Puerarin might improve the opening and forming of coronary collateral circulation to ischemic myocardium in dogs and protect ischemic myocardium.

Animals↗
PubMed1982

Effect of physical training on coronary collateral circulation of the rat.

The influence of physical training on coronary collateral circulation following acute ligation of the left coronary artery was determined in pentobarbital-anesthetized rats. Coronary blood flows were determined with 15-microns microspheres during a wide range of perfusion pressures and during adenosine infusion. The demarcation between normal and ischemic tissue was achieved using nitroblue tetrazolium strain and thioflavin S fluorescence. Contractile performance was not altered by training, with the exception of a lower left ventricular end-diastolic pressure when afterload was elevated. Blood flow to and the size of the central ischemic zone were not influenced by training. However, in border zones, where collateral dependent flow is expected to be most pronounced, blood flow as a percent of normal was increased (16%, P less than 0.02) in trained animals. This increased was abolished by coronary vasodilation with adenosine. These results indicate that training caused a limited increase in collateral blood flow to the border zone. Further, tissue reactivity to adenosine following short periods of ischemia is normal in trained rats but decreased in border (11%) and ischemic (21%, P less than 0.05) zones in sedentary rats. Whether his small increase in blood flow to the border tissue, along with a retained capacity for dilatation, could lead to an improved salvage of tissue remains to be evaluated.

Adenosine↗
PubMed1991

The coronary collateral circulation in normal goats.

This study was undertaken to evaluate the coronary collateral circulation of the goat. Year old, castrated male goats were anesthetized with sodium pentobarbital. A branch of the left circumflex coronary artery was dissected and a snare placed around it. Regional myocardial blood flow was measured by injecting colored microspheres into the left atrium before and during 3 hr of occlusion of this coronary artery. The Area At Risk for infarction, as defined by a left atrial injection of Brilliant Green dye, was divided into a central Ischemic zone and a peripheral Ischemic Border zone. The degree of overlap in the blood flow distributions between the risk and the nonrisk areas was quantitatively assessed by injecting microspheres directly into the artery to the Area At Risk. Baseline blood flow to the normally perfused goat myocardium was 1.13 +/- 0.18 ml/min/g (mean +/- SE). Following occlusion, the flow to the Ischemic zone was 0.07 +/- 0.03 ml/min/g and to the Ischemic Border zone was 0.31 +/- 0.18 ml/min/g. Flow to either zone did not increase during the 3-hr observation period. Overlap at the perimeter of the risk and nonrisk areas was approximately 22%. We conclude that flow to the Ischemic zone is low because the goat has few native collateral blood vessels, and that flow to the Ischemic Border zone is significantly affected by overlap with normal myocardium.

Animals↗
PubMed2005

Ultrasound imaging versus morphopathology in cardiovascular diseases. Coronary collateral circulation and atherosclerotic plaque.

This review article is aimed at comparing the results of histopathological and clinical imaging studies to assess coronary collateral circulation in humans. The role of collaterals, as emerging from morphological studies in both normal and atherosclerotic coronary vessels, is described; in addition, present role and future perpectives of echocardiographic techniques in assessing collateral circulation are briefly summarized.

Cardiovascular Diseases↗