Collateral flow velocity alterations in the supply and receiving coronary arteries during angioplasty for total coronary occlusion

Flow to myocardium following coronary occlusion may not originate solely from collateral channels. Some flow might be derived from overlapping coronary arteries which also perfuse tissue within the territory of the obstructed vessel prior to occlusion. Left atrial microsphere injection during perfusion of the left anterior descending (LAD) artery from a special reservoir containing microsphere-free blood and again after LAD occlusion permitted measurement of noncollateral overlap and total ischemic LAD (TIF) flows, respectively, and mathematical derivation of true collateral flow (TCF). Whereas TIF averaged 0.25 +/- 0.03 ml/min per g, TCF was 0.14 +/- 0.03 ml/min per g, only 50.6% of TIF. The remainder of the TIF represented either inadvertant inclusion of normally perfused tissue with the ischemic LAD myocardium or actual overlap of LAD and left circumflex circulations. 86RbCl was injected simultaneously with the microspheres following coronary occlusion. 86Rb and microsphere densities in the whole heart and ischemic area were closely correlated, although microsphere distribution tended to be more heterogeneous. No segment of ischemic myocardium containing 86Rb was free of microspheres. Therefore, the geometry of undeveloped collateral channels is adequate to permit passage of 15-micron particles. Absolute 86Rb flows were consistently less than microsphere flows.

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Prognostic value of non-invasive coronary artery flow velocity assessment in elderly patients

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.097 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

E Kalinina ◽

A Zagatina ◽

N Zhuravskaya ◽

D Shmatov

Keyword(s):

Myocardial Infarction ◽

Coronary Artery ◽

Elderly Patients ◽

Flow Velocity ◽

Coronary Arteries ◽

Coronary Flow ◽

Prognostic Value ◽

Area Under Curve ◽

Left Coronary Artery ◽

Maximal Velocity

Abstract Funding Acknowledgements Type of funding sources: None. Background There is a high prevalence of coronary artery disease (CAD) in the elderly population. However, symptoms of CAD are often non-specific. Dyspnoe, non-anginal pains are among the main symptoms in older patients. Exercise tests are of limited feasibility in these patients, due to neuro-muscular weakness, physical deconditioning, and orthopaedic limitations. Pharmacological tests often are contraindicated in a substantial percentage of elderly patients. Some recent studies indicate using local flow acceleration during routine echocardiography has prognostic potential for coronary artery assessments without stress testing. The aim of the study was to define the prognostic value of coronary artery ultrasound assessment in patients ≥75 years old. Methods This is a prospective cohort study. Patients ≥ 75 years old who underwent routine echocardiography with additional scans for coronary arteries over a period of 24 months were included in the study. The study group consisted of 80 patients aged 75-90 years (56 women; mean age 79 ± 4). Initial exams were performed for other reasons, primarily for arterial hypertension. Fifteen patients had known CAD. Death, non-fatal myocardial infarction (MI), and revascularization were defined as major adverse cardiac events (MACE). All patients were followed up with at a median of 32 months. Results There were 34 patients with high local velocities in the left coronary artery. Eight deaths, two non-fatal myocardial infarctions occurred, and 13 revascularizations were performed. With a ROC analysis, a coronary flow velocity >110 cm/s was the best predictor for risk of death (area under curve 0.84 [95% CI 0.74–0.92]; sensitivity 75%; specificity 88%). Only the maximal velocity in proximal left-sided coronary arteries was independently associated with death (HR 1.03, 95% CI 1.01; 1.05; p < 0.002), or death/MI (HR 1.03, 95% CI 1.01; 1.04; p < 0.0001). The cut-off value of 66 cm/s was a predictor of all MACE (area under curve 0.87 [95% CI 0.77–0.94]; sensitivity 80%; specificity 86%). Any causes of death or MI occurred more frequently in patients with velocities of >66 cm/s (27% vs. 2%; p < 0.002). The rates of MACE were 58.0% vs. 2%; p < 0.0000001, respectively. Conclusion The analysis of coronary flow in the left coronary artery during echocardiography can be used as a predictor of outcomes in elderly patients. Maximal velocities in proximal left-sided coronary arteries is independently associated with further death or myocardial infarction.

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Coronary Flow Velocity Reserve and Aortic Distensibility Indices in Hypertensive Patients with Hypercholesterolaemia and Normal Epicardial Coronary Arteries

Clinical and Experimental Hypertension ◽

10.1080/10641960903030186 ◽

2009 ◽

Vol 31 (4) ◽

pp. 380-387 ◽

Cited By ~ 2

Author(s):

Attila Nemes ◽

Tamás Forster ◽

Miklós Csanády

Keyword(s):

Flow Velocity ◽

Coronary Arteries ◽

Coronary Flow ◽

Aortic Distensibility ◽

Coronary Flow Velocity Reserve ◽

Hypertensive Patients ◽

Coronary Flow Velocity

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The Prognostic Value of Coronary Flow Velocity Reserve in Two Coronary Arteries During Vasodilator Stress Echocardiography

Journal of the American Society of Echocardiography ◽

10.1016/j.echo.2018.09.002 ◽

2019 ◽

Vol 32 (1) ◽

pp. 81-91 ◽

Cited By ~ 3

Author(s):

Lauro Cortigiani ◽

Fausto Rigo ◽

Francesco Bovenzi ◽

Rosa Sicari ◽

Eugenio Picano

Keyword(s):

Flow Velocity ◽

Coronary Arteries ◽

Coronary Flow ◽

Prognostic Value ◽

Stress Echocardiography ◽

Vasodilator Stress ◽

Coronary Flow Velocity Reserve ◽

Coronary Flow Velocity

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Impact on Diabetes Mellitus on the Epicardial Coronary Flow Velocity Assessed by the Thrombolysis in Myocardial Infarction Frame Count

Angiology ◽

10.1177/0003319708321187 ◽

2008 ◽

Vol 60 (4) ◽

pp. 431-440 ◽

Cited By ~ 1

Author(s):

Ahmet Soylu ◽

Kurtulus Ozdemir ◽

Mehmet Akif Duzenli ◽

Mehmet Yazici ◽

Mehmet Tokac

Keyword(s):

Diabetes Mellitus ◽

Myocardial Infarction ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Flow Velocity ◽

Coronary Arteries ◽

Coronary Flow ◽

Coronary Flow Velocity ◽

And Gender

The aim of this study is to evaluate the effect of type 2 diabetes mellitus on epicardial coronary flow velocity assessed by the thrombolysis in myocardial infarction frame count. The thrombolysis in myocardial infarction frame count was measured in 272 coronary arteries from 101 patients with type 2 diabetes mellitus and in 271 coronary arteries from 104 age- and gender-matched patients without type 2 diabetes mellitus referred for coronary angiography. The thrombolysis in myocardial infarction frame count was measured only in normal arteries or in arteries without significant lesion. By both univariate and multivariate analysis, the thrombolysis in myocardial infarction frame count was not related with either type 2 diabetes mellitus or the duration and glycated hemoglobin levels in the patients with type 2 diabetes mellitus. The thrombolysis in myocardial infarction frame count was significantly associated with body surface area, heart rate, and proximal coronary artery diameter. Type 2 diabetes mellitus did not affect epicardial coronary flow velocity assessed by the thrombolysis in myocardial infarction frame count.

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Abstract W P211: Investigating the Cause for “Collateral Failure” in Stroke-in-Progression: Intracranial Pressure Elevation Reduces Flow Through Collateral Vessels

Stroke ◽

10.1161/str.45.suppl_1.wp211 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Daniel Beard ◽

Damian McLeod ◽

Neil J Spratt

Keyword(s):

Intracranial Pressure ◽

Flow Velocity ◽

Cerebral Perfusion ◽

Perfusion Pressure ◽

Minor Stroke ◽

Collateral Flow ◽

Mca Occlusion ◽

Intracranial Pressure Elevation ◽

Flow Through ◽

Collateral Vessels

Background: Adequacy of the collateral circulation is a major determinant of outcome in stroke patients. Recent human imaging data indicates that collateral failure, rather than reperfusion-reocclusion is the most common cause for early progression in minor stroke. Our previous experimental data shows that intracranial pressure (ICP) rises transiently 24 h after even minor stroke. Herein, we investigated the effect of ICP manipulation on blood flow through collateral vessels during MCA occlusion. Methods: We developed and validated a method to quantify flow velocity and vessel diameter of anterior-middle cerebral artery (ACA-MCA) leptomeningeal collaterals in rats during stroke, using fluorescent microspheres. BIood flow velocity and diameter was quantified in individual collateral vessels and used to calculate absolute flow during MCA occlusion and reperfusion (n = 6). In separate experiments, ICP was increased after MCA occlusion by fluid infusion into the lateral ventricles and effects on relative collateral flow were determined (n = 4). Results: In vitro validation indicated accurate flow quantification (R 2 = 0.99, P<0.0001). Collateral flow was seen to switch from bidirectional to unidirectional flow (toward occluded vessel) and increase by 595 ± 134 % within 10 min of vessel occlusion. Direction and flow changes were variable after MCA reperfusion, however there was a mean flow reduction of 52 ± 15 % by 5 mins. Artificially elevating ICP during MCA occlusion caused a reduction of cerebral perfusion pressure which was strongly correlated with collateral flow reduction (R 2 = 0.90, p<0.0001). Discussion: Our method permits real time quantification of flow through individual collateral vessels during stroke and reperfusion. Intracranial pressure elevation reduced collateral flow, proportional to its effect on cerebral perfusion pressure. Coupled with our previous data indicating significant ICP elevation after even minor stroke, this suggests that transient ICP elevation is the possible cause of the collateral failure recently described in patients with stroke-in-progression.

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Influence of neutrophil depletion on myocardial function and flow after reversible ischemia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1989.256.2.h341 ◽

1989 ◽

Vol 256 (2) ◽

pp. H341-H351 ◽

Cited By ~ 4

Author(s):

P. G. O'Neill ◽

M. L. Charlat ◽

L. H. Michael ◽

R. Roberts ◽

R. Bolli

Keyword(s):

Polymorphonuclear Leukocytes ◽

Coronary Occlusion ◽

Critical Factor ◽

Wall Thickening ◽

Collateral Flow ◽

Vascular Abnormalities ◽

Reversible Ischemia ◽

Neutrophil Depletion ◽

Mediate Cell

We explored the role of polymorphonuclear leukocytes (PMN) in the genesis of contractile dysfunction (myocardial "stunning") and of vascular abnormalities after reversible ischemia. Open-chest dogs underwent a 15-min coronary occlusion and 4 h of reperfusion (REP); treated animals (n = 16) received intravenous goat antiserum against canine PMN, whereas controls received nonimmune goat serum (n = 10) or saline (n = 15). In treated dogs, the average blood PMN levels were 10% of those in saline controls. During ischemia, collateral flow tended to be higher, and paradoxical systolic wall thinning tended to be less in neutropenic dogs, but despite this, recovery of wall thickening after REP was not enhanced in these animals. Similarly, arrhythmias during ischemia or REP did not differ among the three groups. Four hours after REP, both resting and minimal coronary resistance (the latter assessed by adenosine infusion) were higher in the stunned compared with the nonischemic myocardium; these vascular derangements, however, were similar in all three groups. Thus profound neutropenia failed to attenuate mechanical dysfunction, to reduce arrhythmias, and to prevent vascular abnormalities after a 15-min coronary occlusion. Although previous studies have suggested that neutrophils mediate cell death during prolonged ischemia, the present findings suggest that PMN do not contribute importantly to the damage associated with brief, reversible ischemia. The duration of flow reduction may be a critical factor determining whether PMN exacerbate ischemic injury.

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Effects of time on volume and distribution of coronary collateral flow

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1976.230.2.279 ◽

1976 ◽

Vol 230 (2) ◽

pp. 279-285 ◽

Cited By ~ 40

Author(s):

ML Marcus ◽

RE Kerber ◽

J Ehrhardt ◽

FM Abboud

Keyword(s):

Blood Flow ◽

Vascular Resistance ◽

Coronary Occlusion ◽

Marked Decrease ◽

Relative Proportion ◽

Collateral Flow ◽

Coronary Vascular Resistance ◽

Collateral Blood Flow ◽

Coronary Collateral Flow ◽

Hemodynamic Measurements

Changes in the volume and distribution of collateral blood flow were studied during the 1st h after coronary occlusion in nine open-chest dogs. Labeled microspheres (7-10 mum) were injected into the left atrium prior to and 20 s, 5 min, and 60 min after acute occlusion of the midcircumflex coronary artery so that myocardial perfusion to small segments of the entire left ventricle could be measured. The segmental perfusions were classified as normally perfused, severely hypoperfused, moderately hypoperfused, and borderline hypoperfused. Standard hemodynamic measurements were obtained and relative coronary vascular resistance to the normally perfused and hypoperfused zones was calculated. The principal conclusions of the study are as follows: 1) during the 1st h after coronary occlusion the collateral flow to the hypoperfused myocardium increases substantially; 2) the increase in collateral flow is distributed fairly evenly to various hypoperfused zones and is associated with a marked decrease in coronary vascular resistance; and 3) as a result of this influx in collateral flow the size of the hypoperfused area decreases and the relative proportion of severely hypoperfused segments within the hypoperfused area decreases.

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