Circumflex artery occlusion

Huey B, Beller G, Kaiser O, Gibson R. A comprehensive analysis of myocardial infarction due to left circumflex artery occlusion comparison with infarction due to right coronary and left anterior descending artery occlusion. J Am Coll Cardiol 1988 12 1156. 

The eversion graft model for producing thrombosis in the rabbit artery was first described by Hergrueter et al. (1988) and later modified by Jang et al. (1989, 1990) and Gold et al. (1991). A 4- to 6-mm segment of the rabbit femoral or the dog left circumflex artery is excised, everted and then reimplanted into the vessel by end-to-end anastomoses. After restoration of the blood flow, a platelet-rich occlusive thrombus forms rapidly leading to complete occlusion of the vessel. 

In our preliminary study utilizing a model of myocardial infarction in rabbits, when antimyosin IL, IgG-L, PL, or saline placebo were delivered concomitant with circumflex coronary artery occlusion for 45 min... 

Fig. 19 Nitroblue tetrazolium stained heart sections of rabbits with acute myocardial infarction treated with PL (left panel), saline placebo (middle panel) and IL (right panel). The sites of left circumflex coronary artery occlusion can be seen in the middle and right panels to be at the 4th slices by the presence of the silk sutures. Normal myocardium is stained purple or brown, whereas the infarcted regions remain as light colored regions.

Step 1 assess the ST segment in lead I. In the case of depression, the occlusion is located in the RCA, and in the case of elevation, it is located in the circumflex artery (LCX). When the ST segment is isoelectric, one should proceed to Step 2. 

Shen Wei, Xing Hui, Wang Man, Gong Lan. Myocardial infarction due to isolated left circumflex or right coronary artery occlusion. Chin Med J 1991 104 369. 

P12. Petropoulos, P., Influence of hyperbaric oxygenation on the haemodynamic changes and mortality after circumflex coronary artery occlusion. In Clinical Application of Hyperbaric Oxygen (I. Boerema, W. H. Brummelkamp, and N. G. Meijne, eds.), pp. 84r-99. Elsevier, Amsterdam, 1964. 

R3. Roshe, J., and Allen, W., Effects of hyperbaric oxygenation on left circumflex coronary artery occlusion in dogs. Surg. Forum 16, 208-209 (1964). 

ECG Discrimination Between Right and Left Circumflex Coronary Arterial Occlusion in Patients With cute Inferior Myocardial Infarction... 

In Fig. 2.2, the PET perfusion images show severe stenosis or occlusion of the left circumflex (LCx) and right (RCA) coronary arteries with a moderately severe stenosis of the left anterior descending (LAD) coronary artery proximal to its second diagonal branch. The ejection fraction (EF) and regional LV contraction were normal. Therefore, this example illustrates purely ischemic myocardium without scar and without injured or poorly contracting myocardium. 

Fig. 2.2 Positron emission tomography (PET) perfusion images showing severe stenosis/ occlusion of the left circumflex (LCx) and right (RCA) coronary arteries with...

Gold et al. (1991) modified the model to be used in tho-racotomized dogs in partial obstructed left circumflex coronary arteries. The combination of reduced blood flow due to the constrictor, along with an abnormal non-endothelial surface, produces total thrombotic occlusion within 5 min. 

A 31-year-old woman suddenly developed central chest pain, with a normal electrocardiogram. Changes in troponin and creatine kinase MB were consistent with acute myocardial infarction. Drug screening was positive for amphetamines and barbiturates. Coronary angiography showed an aneurysm with 99% occlusion of the proximal left circumflex coronary artery and extravasation of contrast material. A stent was inserted percutaneously and antegrade flow was achieved without residual stenosis. 

Bairey CN, Shah PK, Lew AS, Hulse S. Electrocardiographic differentiation of occlusion of the left circumflex versus the right coronary artery as a cause of inferior acute myocardial infarction. Am J Cardiol 1987 60 456. 

In the Folts model, tirofiban (0.3mg/kg i.v.) gave 85% inhibition of ADP or collagen induced platelet aggregation, and abolished cyclic flow variations in the canine left circumflex coronary artery, with a short duration of action (18min). In the electrically induced thrombosis model, an infusion of tirofiban (10 g/kg/min), which produced 90% inhibition of platelet aggregation ex vivo, delayed or fully prevented occlusive thrombosis in the canine left circumflex coronary artery [145],... 

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