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Assessment of Myocardial Collateral Blood Flow with Contrast Echocardiography.

Kaul S - Korean Circ J (2015)

Bottom Line: Collateral flow under resting conditions (if >25% of normal) is enough to maintain myocardial viability, but may be insufficient to prevent myocardial ischemia under stress.Myocardial contrast echocardiography is arguably the gold standard for experimental and clinical measurement of collateral flow.This review describes several experimental and clinical studies that highlight the importance of the collateral circulation in coronary artery disease.

View Article: PubMed Central - PubMed

Affiliation: Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA.

ABSTRACT
Humans have pre-formed collateral vessels that enlarge with ischemia. In addition, new vessels can be formed within ischemic zones from pre-formed endocardial arcades of vessels providing rich collateral flow. Collateral flow under resting conditions (if >25% of normal) is enough to maintain myocardial viability, but may be insufficient to prevent myocardial ischemia under stress. Coronary angiography is a poor tool for collateral flow assessment. Myocardial contrast echocardiography is arguably the gold standard for experimental and clinical measurement of collateral flow. This review describes several experimental and clinical studies that highlight the importance of the collateral circulation in coronary artery disease.

No MeSH data available.


Related in: MedlinePlus

Images from a dog undergoing 6 hours of left anterior descending artery occlusion with a large MCE defined risk area (A), confirmed by radiolabeled microspheres (B). The risk area is mostly filled with collateral flow several seconds later (C) resulting in a very small infarct (D). The rest of the risk area is supplied by collateral flow that is lower than in the normal remote myocardium. Thus, the circumferential extent of abnormal wall thickening was greater than the circumferential extent of infarction. MCE: myocardial contrast echocardiography.
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Figure 7: Images from a dog undergoing 6 hours of left anterior descending artery occlusion with a large MCE defined risk area (A), confirmed by radiolabeled microspheres (B). The risk area is mostly filled with collateral flow several seconds later (C) resulting in a very small infarct (D). The rest of the risk area is supplied by collateral flow that is lower than in the normal remote myocardium. Thus, the circumferential extent of abnormal wall thickening was greater than the circumferential extent of infarction. MCE: myocardial contrast echocardiography.

Mentions: Fig. 7 is an example of a perfusion defect on MCE (Fig. 7A) that corresponds in size to that using radiolabeled microspheres, which is the gold standard for quantification of nutrient blood flow (Fig. 7B). The infarct size on post-mortem examination is much smaller (Fig. 7D) because of extensive collateral blood flow, as seen in a MCE image late after microbubble destruction (Fig. 7C). Fig. 8 depicts the flow-function relation where the red dots represent infarcted tissue, the blue dots represent normal remote tissue and the green dots represent the collateral-supplied zones on the infarct margins. All data points fall on the same line, indicating that there is no tethering; but functional disparities are explained solely by disparities in flow.


Assessment of Myocardial Collateral Blood Flow with Contrast Echocardiography.

Kaul S - Korean Circ J (2015)

Images from a dog undergoing 6 hours of left anterior descending artery occlusion with a large MCE defined risk area (A), confirmed by radiolabeled microspheres (B). The risk area is mostly filled with collateral flow several seconds later (C) resulting in a very small infarct (D). The rest of the risk area is supplied by collateral flow that is lower than in the normal remote myocardium. Thus, the circumferential extent of abnormal wall thickening was greater than the circumferential extent of infarction. MCE: myocardial contrast echocardiography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4580691&req=5

Figure 7: Images from a dog undergoing 6 hours of left anterior descending artery occlusion with a large MCE defined risk area (A), confirmed by radiolabeled microspheres (B). The risk area is mostly filled with collateral flow several seconds later (C) resulting in a very small infarct (D). The rest of the risk area is supplied by collateral flow that is lower than in the normal remote myocardium. Thus, the circumferential extent of abnormal wall thickening was greater than the circumferential extent of infarction. MCE: myocardial contrast echocardiography.
Mentions: Fig. 7 is an example of a perfusion defect on MCE (Fig. 7A) that corresponds in size to that using radiolabeled microspheres, which is the gold standard for quantification of nutrient blood flow (Fig. 7B). The infarct size on post-mortem examination is much smaller (Fig. 7D) because of extensive collateral blood flow, as seen in a MCE image late after microbubble destruction (Fig. 7C). Fig. 8 depicts the flow-function relation where the red dots represent infarcted tissue, the blue dots represent normal remote tissue and the green dots represent the collateral-supplied zones on the infarct margins. All data points fall on the same line, indicating that there is no tethering; but functional disparities are explained solely by disparities in flow.

Bottom Line: Collateral flow under resting conditions (if >25% of normal) is enough to maintain myocardial viability, but may be insufficient to prevent myocardial ischemia under stress.Myocardial contrast echocardiography is arguably the gold standard for experimental and clinical measurement of collateral flow.This review describes several experimental and clinical studies that highlight the importance of the collateral circulation in coronary artery disease.

View Article: PubMed Central - PubMed

Affiliation: Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA.

ABSTRACT
Humans have pre-formed collateral vessels that enlarge with ischemia. In addition, new vessels can be formed within ischemic zones from pre-formed endocardial arcades of vessels providing rich collateral flow. Collateral flow under resting conditions (if >25% of normal) is enough to maintain myocardial viability, but may be insufficient to prevent myocardial ischemia under stress. Coronary angiography is a poor tool for collateral flow assessment. Myocardial contrast echocardiography is arguably the gold standard for experimental and clinical measurement of collateral flow. This review describes several experimental and clinical studies that highlight the importance of the collateral circulation in coronary artery disease.

No MeSH data available.


Related in: MedlinePlus