Postoperative Evaluation of Myocardial Blood Flow in Aorta-to-Coronary Artery Vein Bypass Grafts Using the Xenon-Residue Detection Technic

Lichtlen, Paul R.; Moccetti, T; Halter, Jeffrey B.; Schönbeck, M; Senning, Å

doi:10.1161/01.cir.46.3.445

Cited by 38 publications

(8 citation statements)

References 20 publications

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“…35 42 Several experimental studies documented that a decrease in flow rate in a severely obstructed artery tends to increase the degree of obstruction that is necessary to impede flow.3-6, [17][18][19] Whether this consideration is a major determinant of the findings presented in this study must be proved. Most experimental studies considered the effects of changes in flow rates in a single vessel.…”

Section: Discussionmentioning

confidence: 93%

“…Despite the well-known differences between coronary anatomy of humans and dogs,'4 blood flow in the left anterior descending artery of man was also significantly higher than in the right coronary artery in several studies using the 133-xenon clearance tech- [40][41][42] nique. Of particular interest are the angiographic data reported by Cosby et al,43 who showed that stenosis of the right coronary artery was the most frequent finding in patients with coronary artery disease, particularly if angina pectoris was present.…”

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

Quantitative difference in "critical" stenosis between right and left coronary artery in man.

Rafflenbeul¹,

Urthaler²,

P³

et al. 1980

Circulation

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Coronary artery stenoses that limit blood flow below demand are considered critical. In this comparative study we investigated whether the same degree of stenosis in either the proximal third of the right coronary artery (RCA) or the proximal third of the left anterior descending artery (LAD) causes critical flow reduction. Lesions were quantified from 35-mm cinefilms in multiple projections using a vernier caliper. These morphometric measurements were correlated with various manifestations of critical flow reduction, such as angina pectoris, development of collateral vessels and segmental wall motion abnormalities. In 13 patients with anginal pain and isolated RCA stenosis, the mean degree of obstruction was 63% area stenosis, which was significantly lower (p < 0.05) than that measured in 17 symptomatic patients who had isolated obstructions of the LAD (77% area stenosis). In patients with an identical degree of obstruction (78%) in either the LAD or RCA, collateral vessels were angiographically demonstrable in 53% of the RCA stenoses but in only 29% of the LAD stenoses. Furthermore, when the stenoses were less than 63% in the RCA and LAD, regional wall motion abnormalities were more frequently (p < 0.05) associated with RCA than with LAD stenoses. These observations indicate that a significantly smaller percent area of stenosis is critical in the RCA than in the LAD.

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 98%

Quantitative difference in "critical" stenosis between right and left coronary artery in man.

Rafflenbeul¹,

Urthaler²,

P³

et al. 1980

Circulation

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“…"-" In general, the studies have indicated the efficacy of aortocoronary bypass grafts for myocardial revascularization under conditions of rest," and in a few patients, with exercise. '2' 13 Comparisons have not been made, however, between preand postoperative flow characteristics of individual patients.…”

Section: Additional Indexing Wordsmentioning

confidence: 99%

The Effect of Aortocoronary Bypass Grafts on Myocardial Blood Flow Reserve and Treadmill Exercise Tolerance

et al. 1974

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Twenty-five patients had myocardial blood flow reserve determinations (percentage increase in myocardial blood flow with stress), treadmill exercise tests and coronary and bypass cineangiography preand postaortocoronary bypass surgery. Twenty of the patients had the postoperative studies performed three months after operation, three at two months and two at five and six months, respectively.Eleven of the 25 patients had all significant coronary artery obstructions (75%1 or greater) bypassed and all grafts were open at the time of restudy. Preoperatively, blood flow reserve had been abnormal in nine and all had positive treadmill tests. Postoperatively, all eleven patients had normal myocardial blood flow response to stress and treadmill tests were negative in ten (one patient was not restudied on the treadmill).In six patients, no patent grafts could be demonstrated. These patients continued to show abnormal blood flow reserve and positive treadmill studies.Eight of the 25 patients had partial revascularization in that some grafts were open, some closed, and some significantly occlusive lesions were not bypassed. Four of these eight patients had normal flow and treadmill studies and the remainder continued to have an abnormal response to one or both of the measurements.The relationship between treadmill exercise response, myocardial blood flow reserve, and graft patency was significant at the 0.005 level for patients with all grafts open or closed. No significant correlation was obtained between any of the measurements in those patients with partial revascularization.The data indicate that successful aortocoronary bypass grafting provides myocardial revascularization as reflected in a return to normal of the myocardial blood flow reserve and response to treadmill stress testing. Additional Indexing Words:Coincidence counting Revascularization Rubidium-84 SEVERAL STUDIES assessing the effects of aortocoronary bypass surgery in relief of angina pectoris' and on left ventricular performance have been reported.2 5 There also have been studies measuring graft and myocardial blood flow at the time of surgery6`10 and in the postoperative period."-" In Computer ST-segment quantitation general, the studies have indicated the efficacy of aortocoronary bypass grafts for myocardial revascularization under conditions of rest," and in a few patients, with exercise.'2' 13 Comparisons have not been made, however, between preand postoperative flow characteristics of individual patients.The purpose of this study was to determine whether myocardial blood flow reserve, the ability to increase myocardial blood flow with increased myocardial oxygen demand, and exercise capacity as measured by treadmill exercise testing were improved following aortocoronary bypass surgery. Patients were studied before and from two to six months after insertion of bypass grafts. Myocardial blood flow, as measured by a coincidence counting system and single bolus of 84Rb'5-'7 and treadmill exercise responses were compared with the patency of the grafts a...

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“…Atherosclerosis is major cause of cardiovascular disease, including the myocardial infraction (MI). Coronary artery bypass grafting is recognized to improve symptoms and prolong survival for MI (37,43). Apart from the human greater saphenous vein, the human radial artery is the other major conduit of choice for the coronary arteries bypass grafts.…”

Section: Introductionmentioning

confidence: 99%

Functional Characterization of Intracellular pH Regulators Responsible for Acid Extrusion in Human Radial Artery Smooth Muscle Cells

Lee

Tsai²,

Chang³

et al. 2014

Chin. J. Physiol.

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Intracellular pH (pHi) is a critical factor influencing many important cellular functions. Acid extrusion carriers such as an Na⁺/H⁺ exchanger (NHE) Na⁺/HCO₃⁻ cotransporter (NBC) and monocarboxylate transporters (MCT) can be activated when cells are in an acidic condition (pHi < 7.1). Human radial artery smooth muscle cells (HRASMC) is an important conduit in coronary artery bypass graft surgery. However, such far, the pHi regulators have not been characterized in HRASMCs. We therefore investigated the mechanism of pHi recovery from intracellular acidosis and alkalosis, induced by NH₄Cl-prepulse and Na-acetate-prepulse, respectively, using intracellular 2',7'-bis(2-carboxethyl)-5(6)- carboxy-fluorescein (BCECF)-fluorescence in HRASMCs. Cultured HRASMCs were derived from the segments of human radial artery that were obtained from patients undergoing bypass grafting. The resting pHi is 7.22 ± 0.03 and 7.17 ± 0.02 for HEPES- (nominally HCO₃⁻-free) and CO₂/HCO₃⁻- buffered solution, respectively. In HEPES-buffered solution, a pHi recovery from induced intracellular acidosis could be blocked completely by 30 μM HOE 694 (3-methylsulfonyl-4-piperidinobenzoyl, guanidine hydrochloride) a specific NHE inhibitor, or by removing [Na⁺]₀. In 3% CO₂/HCO₃⁻-buffered solution, HOE 694 slowed the pHi recovery from the induced intracellular acidosis only, while adding together with DIDS (a specific NBC inhibitor) or removal of [Na⁺]₀ entirely inhibited the acid extrusion. Moreover, α-cyano-4-hydroxycinnamate (CHC; a specific blocker of MCT) blocked the lactate-induced pHi changes. In conclusion, we demonstrate, for the first time, that 3 different pHi regulators responsible for acid extruding, i.e. NHE and NBC, and MCT, are functionally co-existed in cultured HRASMCs.

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Postoperative Evaluation of Myocardial Blood Flow in Aorta-to-Coronary Artery Vein Bypass Grafts Using the Xenon-Residue Detection Technic

Cited by 38 publications

References 20 publications

Quantitative difference in "critical" stenosis between right and left coronary artery in man.

Quantitative difference in "critical" stenosis between right and left coronary artery in man.

The Effect of Aortocoronary Bypass Grafts on Myocardial Blood Flow Reserve and Treadmill Exercise Tolerance

Functional Characterization of Intracellular pH Regulators Responsible for Acid Extrusion in Human Radial Artery Smooth Muscle Cells

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