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At least 19 recordsLinked to original sources
PubMed2001

Intravascular ultrasound assessment of the stenoses location and morphology in the left main coronary artery in relation to anatomic left main length.

Eighty-seven left main stenoses were evaluated by angiography and intravascular ultrasound. Intravascular ultrasound analysis included left main length (bifurcation to ostium), stenosis location, stenosis length, stenosis external elastic membrane, lumen, plaque & media cross-sectional area (CSA), plaque burden (plaque & media/external elastic membrane CSA), calcium arc, calcium length, eccentricity, and remodeling index (stenosis/reference external elastic membrane CSA). Long anatomic left main arteries (length > or =10 mm, n = 43) were compared with short anatomic left main arteries (length <10 mm, n = 44) regarding stenosis location. Ostial (proximal third of left main artery) (n = 32) and nonostial (midthird and distal third) stenoses (n = 55) were compared regarding stenosis morphology. Short anatomic left main arteries developed stenoses more frequently near the ostium (ostium 55%, bifurcation 38%). Conversely, long anatomic left main arteries developed stenoses more frequently near the bifurcation (ostium 18%, bifurcation 77%, p = 0.001). Ostial left main stenoses were more common in women (44% vs 20%, p = 0.02), had larger lumen area (6.2 +/- 2.2 vs 4.6 +/- 2.3 mm(2), p = 0.002), less plaque burden (62 +/- 15% vs 80 +/- 9%, p <0.0001), less calcification (arc = 78 +/- 65 degrees vs 195 +/- 101 degrees, p <0.0001), and more negative remodeling (remodeling index = 0.87 +/- 0.19 vs 1.01 +/- 0.21, p = 0.005) than nonostial left main stenoses. Most ostial left main stenoses were categorized as eccentric (97% vs 76%, p = 0.01). Short and long left main arteries develop stenoses at different locations. Stenosis morphology was significantly different in these 2 locations.

Aged↗
PubMed1991

Exercise testing and left main coronary artery stenosis. Can patients with left main disease be identified?

Exercise testing is commonly used to evaluate patients with coronary artery disease who have serious anatomic characteristics. To study the characteristic exercise test variables in patients with left main coronary artery disease, the computerized data base of the Hungarian Institute of Cardiology Exercise Test Laboratory was used. Among 2,378 patients who had undergone a supine bicycle exercise test and who had abnormal coronary angiographic results, 65 patients with significant (greater than 50 percent diameter narrowing) stenosis of the left main coronary artery were found. The 65 patients were subgrouped according to their previous history and other vessel involvement. Nine patients had isolated left main coronary artery disease and no myocardial infarction (group 1); 28 patients had left main coronary artery stenosis and another diseased vessel but no prior myocardial infarction (MI) (group 2); and 28 patients had left main coronary artery disease, another diseased vessel, and a prior MI (group 3). For comparison, the 27 patients selected to be the control group (group C) had no history of MI but had significant stenosis of both the left anterior descending and the left circumflex arteries. Exercise time, calculated oxygen consumption, maximal work load, time to ST depression, prevalence of ST segment depression, and maximal ST depression were similar in the groups. Maximal heart rate and double product were higher in group 1, but we could find no single variable or group of variables characteristic of left main coronary artery disease.

Coronary Angiography↗
PubMed1992

Left main coronary trunk compression by dilated main pulmonary artery in atrial septal defect. Report of three cases.

Narrowing of the left main coronary trunk, which was compressed by the dilated pulmonary artery, was associated with atrial septal defect in three adults. One of them had severe pulmonary hypertension. Coronary angiograms revealed localized narrowing of the left main coronary trunk, and the left main coronary trunk had a concave shape. No stenosis of other coronary arteries was observed. In all patients the atrial septal defect was closed with a polytetrafluoroethylene patch. In the patient with 75% narrowing of the left main coronary trunk, aorta-coronary bypass was performed; it was not performed in the two with 50% narrowing. In two survivors postoperative coronary angiograms showed that the narrowing of the left main coronary trunk improved or disappeared. These results suggest that markedly dilated pulmonary arteries easily compress the left main coronary trunk and cause narrowing, which improves after atrial septal defect closure.

Constriction, Pathologic↗
PubMed2004

[Main clinical and surgical determinants of in-hospital mortality after surgical revascularization of left main coronary artery stenosis: 2 year retrospective study (1998-1999)].

UNLABELLED: Stenosis of left main coronary artery (LMCA) is a common finding on coronary angiographies (7 to 10%). Mortality is very high for conservative therapy in comparison with surgery, which provides very good long-term outcome and is accepted as the standard therapy of this condition. Over the last few years, percutaneous coronary intervention (PCI) has become a new alternative in selected patients. AIM OF THE STUDY: To assess in hospital mortality in subjects referred to our surgical unit for coronary artery bypass grafting (CABG) and to identify the main clinical and surgical determinants of in-hospital mortality. METHODS: Two year retrospective analysis (1998-1999) of in-hospital mortality and morbidity of patients having left main stenosis referred for CABG. RESULTS: Among a group of 1443 patients operated for coronary heart disease, LMCA stenosis was found in 330 patients (22.9%). The mean age was 63 +/- 8.6 years. Elective surgery was done in 173 patients (52.4%), and acute operation (i.e. urgent, emergent or desperate) in 157 patients (47.6%). The total in-hospital mortality was 4.2% (14/330). Elective surgery in-hospital mortality was 1.7% (3/173) and urgent surgery in-hospital mortality was 7% (11/157). The main risk factors of in-hospital mortality were age > 68 years, low ejection fraction (LVEF<0.4), history of myocardial infarction, gender (female) and urgency of the operation. CONCLUSION: The proportion of patients undergoing CABG for left main stenosis is relatively high in our center and their mortality is quite low especially for elective operations. As the mortality of patients treated by PCI for LMCA stenosis is similar to surgery in high-risk patients, we postulate that this approach can be a real alternative treatment for such patients. Because of its potential benefit, combined revascularisation is also an alternative that should be considered in some cases. Furthermore, as a new generation of coated stents has emerged in the treatment of restenosis after PCI, we hypothesize that this method can in the near future be accepted as equivalent to surgery. However several randomized clinical trials must first be conduced prove this point.

Age Factors↗
PubMed1998

Physician partnering in Maine: an update from the Maine Medical Assessment Foundation.

BACKGROUND: The Maine Medical Assessment Foundation (MMAF) has involved the participation of hundreds of physicians in study groups to analyze data on small-area variation and assess physician decision-making patterns. In 1991 the MMAF model was replicated across a tri-state area (Maine, New Hampshire, and Vermont) in an effort called the Outcomes Dissemination Project. THE OUTCOMES DISSEMINATION PROJECT: Five specialty study groups, each meeting three times a year, examined local and national utilization data and guidelines and research findings, participated in outcomes studies and patient education, and disseminated their findings through society presentations and other feedback efforts. Physician surveys indicated that all but one of the study groups were successful in making their existence and activities known to the broader medical community. PARTNERING WITH PURCHASERS AND MEDICAID: In the "Partnership Projects," the MMAF and relevant study groups, collaborating with a Maine business coalition, analyzed variations in utilization across employers, types of health plans (for example, health maintenance organization, preferred provider organization, fee-for-service), and small areas. Through this process, coalition members learned about small-area analysis and the implications of variations in utilization for cost and quality. The first year of the collaborative projects focused on several issues, including the development and dissemination of a practice guideline for the care of patients with chest pain; the dissemination of a practice guideline for the treatment of patients with acute low back pain; and a project designed to address cesarean section rates. SUMMARY: Innovative partnerships have been crafted to allow the tenets of the MMAF's working relationships with the medical community to remain intact, ensuring the ongoing interest and cooperation of hundreds of Maine physicians.

Community Networks↗
PubMed2001

Total occlusion of left main coronary artery by dilated main pulmonary artery in a patient with severe pulmonary hypertension.

A 34-year-old woman was admitted to the hospital because of recently aggravated right heart failure without angina for 5 months. When she was 25 years old, patch repair with Polytetrafluoroethylene (PTFE) was performed for the secondum type of atrial septal defect (ASD) with moderate pulmonary hypertension. The chest PA, echocardiography and cardiac catheterization at current admission revealed Eisenmenger syndrome without intracardiac shunt. Chest CT scan with contrast revealed markedly dilated pulmonary trunk, both pulmonary arteries and concave disfigurement of the left side of the ascending aorta suggesting extrinsic compression, as well as total occlusion of the ostium of the left main coronary artery that was retrogradly filled with collateral circulation from the right coronary artery. The coronary angiography showed normal right coronary artery and the collaterals that come out from the conus branch to the mid-left anterior descending artery (LAD) and that from distal right coronary artery to the left circumflex artery (LCX) and to the distal LAD, respectively. On aortography, the left main coronary artery was not visualized with no stump, suggestive of total occlusion of the ostium of the left main coronary artery. From our experience, it is possible to say that the occlusion of the ostium of the left main coronary can be induced by the dilated pulmonary artery trunk due to ASD with pulmonary hypertension and that, if the ASD closure was too late, the narrowing or obstruction of the left coronary artery could not be resolved even after operation owing to irreversible pulmonary hypertension.

Adult↗
PubMed2001

[Left main coronary trunk compression by dilated main pulmonary artery in a patient with atrial septal defect].

A 12-year-old girl with atrial septal defect combined with pulmonary hypertension and 90% stenosis of the left main coronary artery caused by dilated pulmonary artery was scheduled for atrial septal closure and coronary artery bypass graft under general anesthesia. During the echocardiographic examination to evaluate the anatomical relationship between the pulmonary artery and left main coronary trunk, bradycardia and a depression of ST-segment on electrocardiogram appeared suddenly when the operator compressed the pulmonary artery with a probe of echocardiography from the operative field. The circulatory collapse and ischemic change on electrocardiogram might have been caused by a further reduction of blood flow to the left main coronary trunk narrowed originally by dilated pulmonary artery. Although various etiologies, such as atherosclerosis, syphilis, and congenital abnormalities are widely known to cause stenosis of the left main coronary trunk, external compression by dilated pulmonary artery has not been widely known. Malignant arrhythmias from coronary artery compression with subsequent ischemia could contribute to an incidence of sudden death. Coronary angiography and magnetic resonance imaging are useful for the preoperative evaluation. Careful management is needed to protect such a patient from ischemic event in the perioperative period.

Anesthesia, General↗
PubMed1994

[A case report of patch angioplasty of the left main coronary artery for isolated left main coronary artery disease].

A 49-year-old woman was admitted to our hospital because of palpitation and right shoulder pain. Examinations showed isolated left main coronary artery disease. Surgical angioplasty of left main coronary artery was considered. The left main stem was approached anteriorly. Pericardium was chosen for patch material and the left main coronary artery was enlarged from 1.5 to 4.0 mm in diameter. Postoperative course was very stable, and postoperative angiography revealed an excellent result.

Angioplasty↗
PubMed1991

Analysis of the chainlength dependence of lipid phase transition temperatures: main and pretransitions of phosphatidylcholines; main and non-lamellar transitions of phosphatidylethanolamines.

The dependence on chainlength, n, of the temperatures at which the various thermotropic phase transitions in phospholipid bilayers take place can be fitted to high accuracy with an expression of the form: Tt = Tt infinity (1-A/(n-d)) where Tt infinity, A and d are the constants to be fitted. This expression works well with literature values for the main and pretransitions of saturated straight-chain phosphatidylcholines, for the main transition of isobranched- and anteisobranched-chain phosphatidylcholines, and for the main and non-lamellar phase transitions of saturated straight-chain phosphatidylethanolamines, and also for diacylglycerol glycolipids. The parameters in the fit can be related thermodynamically to the calorimetric properties of the phase transition. The constants A and d are related to the end effects in the chainlength dependence of the transition enthalpy and transition entropy, respectively, and the transition temperature extrapolated to infinite chainlength, Tt infinity, is determined by the ratio of the incremental transition enthalpy and transition entropy per methylene group. A reasonable correspondence is found between the chainlength dependence of the transition temperature and of the transition enthalpy and transition entropy for saturated straight-chain diacylphosphatidylcholines. It is likely, however, that the expression for the chainlength dependence of the transition temperature may be of more general applicability, because, on the one hand of the greater inherent precision of the transition temperature measurements, and on the other hand because the expression for the transition temperature is of more general validity, provided that the chainlength dependence of the incremental transition enthalpy and entropy are the same.

Gels↗
PubMed1999

Catheter-based reperfusion of unprotected left main stenosis during an acute myocardial infarction (the ULTIMA experience). Unprotected Left Main Trunk Intervention Multi-center Assessment.

The ULTIMA registry was a prospective, multicenter, international registry of 277 patients who underwent percutaneous coronary interventions of unprotected left main trunk stenosis. The 40 patients who underwent an emergency percutaneous left main intervention for acute myocardial infarction are the focus of this study. We compared the results of primary angioplasty with primary stenting, characterizing both the short-term (in-hospital) and long-term (12-month) outcomes. Of the 40 patients, 23 underwent primary angioplasty, whereas 17 underwent primary stenting. The angiographic success rate was an 88% for the cohort. The in-hospital death or coronary artery bypass grafting rate was 65% for the entire group, 74% for the percutaneous transluminal coronary angioplasty group (PTCA), and 53% for the stent group (p = 0.2). The in-hospital death rate was 55% for the entire cohort, 70% for the PTCA group, and 35% for the stent group (p = 0.1). The 12-month rate of death or bypass surgery was 83% and 58% for the PTCA and stent groups, respectively (p = 0.047). The 12-month survival rate was 35% and 53% for the PTCA and stent groups, respectively (p = 0.18). Bypass surgery was required in 6 patients in the PTCA group and 2 patients in the stent group (p = 0.07). Patients undergoing percutaneous interventions for unprotected left main myocardial stenosis during an acute myocardial infarction are critically ill; an initial percutaneous revascularization approach appears feasible and may be the preferred revascularization strategy. Primary stenting was associated with improved clinical outcomes.

Aged↗
PubMed1981

Determination of three main antileprosy drugs and their main metabolites in serum by high-performance liquid chromatography.

The simultaneous analysis of main antileprosy drugs such as 4,4'-diaminodiphenyl sulfone (DDS), clofazimine, rifampicin and their main metabolites in serum was examined by high-performance liquid chromatography using a muBondapak C18 column. When the drugs dissoluted from serum were developed by tetrahydrofuran-0.5% acetic acid (40:60), clofazimine and rifampicins could be analyzed separately. Apart from the mutual separation of water-soluble conjugates of DDS, the individual analysis of DDS, its main liposoluble metabolite and a few related sulfone compounds is possible when the drugs are first developed by acetonitrile-water (20:80). By the use of tetrahydrofuran-water (50:50) containing PIC B-5, the rapid measurement of clofazimine isolated from the other compounds is also possible.

Animals↗
PubMed1997

Stent placement in surgically reimplanted left main coronary artery in patient with anomalous origin of left main coronary artery from pulmonary artery.

Surgical repair of a 29-year-old woman's left coronary artery with an anomalous origin from the pulmonary artery was performed by reimplantation of the left main artery into the aorta, together with coronary artery bypass grafting. Subsequent stenosis of the reimplanted left main artery was treated with successful Palmaz-Schatz stent placement.

Adult↗
PubMed2003

An alternative way of characterising the bonding in compounds featuring main-group elements and with the potential for multiple bonding: on the dissociation of binary main-group hydrides.

Herein the bonding in compounds featuring main-group elements and with the potential for multiple bonding is studied theoretically by examination of their fragmentation into two fragments that still exhibit the same structure as they had in the molecule prior to dissociation. The fragments were calculated both in their electronic ground state and in an excited electronic state, in which the number of unpaired electrons is equal to the maximal number of bonds in the compounds before dissociation. The energies of the fragmentation processes (DeltaE(frag)) can be more directly linked to the bond strengths than the dissociation energies (DeltaE(diss)), because of the absence of any secondary effects like relaxation of the electronic state or of the geometry of the fragments. These relaxation energies of the fragments (DeltaE(frag)) are also studied herein. The energies derived in this work allow for an accurate comparison of the bonding properties in main-group-element hydrides. The trends of the fragmentation and relaxation energies are discussed in detail. It will be shown that the relaxation energies allow for a classification of the bonds ("classical" sigma and pi bonds or donor-acceptor interactions), while the fragmentation energies are good quantitative measures for the total bond strength. Similar calculations are on the way to explore the bonding in systems in which the hydrogen atoms are replaced by organic groups or halogen atoms.

Journal Article↗
PubMed1998

New left main trunk reconstruction technique using a flap of the main pulmonary arterial wall.

A new technique is described for ostiumplasty of the left main coronary artery using a flap of the main pulmonary arterial wall. Venous or pericardial patches are conventionally used to enlarge coronary ostial lesions, we used a flap of the pulmonary arterial wall with expectation that it is viable over the long term. This technique seems to surpass conventional coronary artery bypass grafting.

Angina Pectoris↗
PubMed1993

Supported angioplasty with synchronized retroperfusion in high-risk patients with left main trunk or near left main trunk obstruction.

To test the feasibility of synchronized retroperfusion (SRP) as a support device of percutaneous transluminal coronary angioplasty (PTCA) for high-risk patients, 10 patients with left main trunk or near left main trunk obstruction underwent PTCA with SRP. An 8.5F retroperfusion catheter was inserted from the antecubital vein into the coronary sinus. Arterial blood was supplied through the catheter into the myocardium with a retroperfusion pump during the diastolic phase by means of ECG triggering. In all patients, the narrowings were successfully dilated and an improvement of more than 20% in the luminal diameter stenosis was achieved; however, narrowing of more than 50% (58%) remained in one patient. In all patients, systemic hemodynamics was maintained for more than 30 seconds during balloon inflation. In seven patients, a 60-second balloon inflation was possible without any collapse of systemic hemodynamics. To test the protective effect of SRP on myocardial ischemia and impairment of systemic hemodynamics, balloon inflation without SRP was performed in eight patients after successful dilatation. The duration for balloon inflation with SRP (71 +/- 30 seconds; n = 8) was significantly longer than that without SRP (56 +/- 30 seconds; n = 8). The decrease in systolic aortic pressure, the increase in pulmonary diastolic pressure, and ST-T segment elevation in the precordial lead of ECG during balloon inflation with SRP were less than those during balloon inflation without SRP. After PTCA, angina was not provoked by exercise stress testing in any of the 10 patients. We concluded that SRP is a beneficial support device of PTCA for high-risk patients.

Aged↗
PubMed1994

Influence of right coronary artery stenosis on exercise test responses and survival in patients with left main or left main equivalent disease.

Forty-two patients with angiographically documented left main coronary artery (LM) disease (luminal occlusion > or = 50%) and 30 patients with left main equivalent (LMEQ) disease (> or = 70% luminal occlusion of both the proximal left anterior descending artery and proximal left circumflex artery) were studied to determine the role of right coronary artery (RCA) involvement on exercise test responses and survival. Significant (> or = 70%) RCA stenosis was present in 30 (72%) of the 42 LM patients and 16 (53%) of the 30 LMEQ patients. No significant differences were observed between LM and LMEQ patients in any clinical or exercise variables or survival. Thus both groups were combined for analysis of the influence of RCA involvement (i.e., LM/LMEQ with RCA versus LM/LMEQ without RCA disease). Greater ischemic responses were observed in the LM/LMEQ group with significant stenosis of the RCA. The presence of RCA stenosis was associated with significantly greater horizontal or downsloping ST-segment depression during exercise (2.4 +/- 1.2 mm vs 1.3 +/- 1.4 mm; p < 0.001), and prolonged recovery time until normalization of the ST segment (3.2 +/- 1.4 min vs 2.0 +/- 1.9 min; p < 0.01). The LM/LMEQ without RCA disease group behaved like the subgroup with two-vessel disease, and responses of the LM/LMEQ group with RCA disease were similar to the group with three-vessel disease. The annual survival in LM/LMEQ with RCA disease was worse than that in LM/LMEQ without RCA disease (average annual mortality rates = 7.5% vs 1.0%, respectively; p = 0.05). Infarct-free survival in LM/LMEQ with RCA disease was also lower than that in LM/LMEQ without RCA disease. Thus although patients with LM and LMEQ were similar in terms of survival and exercise responses, the presence of RCA stenosis was associated with significantly greater ST-segment depression, a prolonged recovery time until normalization of the ST segment, a fivefold increase in the death rate, and higher morbidity from myocardial infarction over a 5-year period of follow-up. Involvement of the RCA should be considered when making decisions concerning medical-surgical management of patients with severe coronary artery disease.

Aged↗