Texas Heart Institute journal
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In Part 1 of this review, we discussed how plaque rupture is the most common underlying cause of most cases of unstable angina/non-ST-segment-elevation myocardial infarction (UA/NSTEMI) and how early risk stratification is vital for the timely diagnosis and treatment of acute coronary syndromes (ACS). Now, in Part 2, we focus on the medical therapies and treatment strategies (early conservative vs early invasive) used for UA/NSTEMI. We also discuss results from various large randomized controlled trials that have led to the contemporary standards of practice for, and reduced morbidity and death from, UA/NSTEMI. ⋯ An early-invasive-treatment strategy is of most benefit to high-risk patients, whereas an early-conservative strategy is recommended for low-risk patients. Adjunctive medical therapy with acetylsalicylic acid, clopidogrel or another adenosine diphosphate antagonist, glycoprotein IIb/IIIa inhibitors, and either low-molecular-weight heparin or unfractionated heparin, in the appropriate setting, further reduces the risk of ischemic events secondary to thrombosis. Short- and long-term inhibition of platelet aggregation should be achieved by appropriately evaluating the risk of bleeding complications in these patients.
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The initial and long-term benefits of coronary artery bypass grafting depend upon maintaining the coronary blood flow supplied by the graft. In order to devise a scoring system for predicting graft patency, we evaluated presumptive correlations between saphenous vein graft patency and the characteristics of saphenous veins that were used as conduits in coronary revascularization. We prospectively evaluated 1,000 saphenous vein segments that were implanted in 403 consecutive patients who underwent on-pump coronary artery bypass grafting at our hospital from January 2006 through February 2009. ⋯ A cutoff score of 7 yielded 87.8% sensitivity and 82.8% specificity. Our scoring system has good prognostic value. We believe that it can assist surgeons in choosing the most appropriate conduit and target vessel for coronary artery bypass grafting, especially in high-risk patients who are particularly dependent on blood flow through saphenous vein grafts.
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Extrinsic compression of the left main coronary artery by a massively dilated pulmonary artery in patients who have severe pulmonary hypertension can lead to significant myocardial ischemia. A 58-year-old man with a large patent ductus arteriosus and Eisenmenger syndrome presented with angina at rest and worsening heart failure of 3 months' duration. ⋯ Multislice computed tomographic imaging after 6 months showed stent patency and the intimate relation of the stented vessel to the dilated main pulmonary trunk. We discuss diagnostic and management issues pertaining to this uncommon clinical entity.
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Case Reports
The risk of performing cardiopulmonary bypass in malaria patients: a small case series.
The effects of cardiopulmonary bypass on patients who have active or dormant malaria are unknown. What is known is that malaria-induced hemolysis can be exacerbated by cardiopulmonary bypass. We report 3 cases in which patients with active or dormant malaria underwent open-heart surgery. ⋯ We suggest preoperative quinine prophylaxis for patients with a history of malaria whose blood smears are negative for parasites, and we advocate more radical preoperative treatment with quinine for patients whose blood smears are positive at presentation. These measures appear to prevent hemolysis and fever during both the preoperative and postoperative periods. However, there is need of a multicenter study to ascertain the actual effects of cardiopulmonary bypass on patients with malaria.
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The incidence of arrhythmias after acute myocardial infarction of the inferior wall varies with the affected segment and increases when there is right ventricular involvement. This paper provides a clear review of the blood supply to the conduction system and gives an anatomic explanation of that supply. We dissected 20 human hearts after anterograde and retrograde injection of latex. ⋯ The incidence of arrhythmias after acute myocardial infarction of the inferior wall is greater when the occlusion of the coronary trunk is at or near the origin. This is due to the existence of the right superior descending artery, which is given off by the right coronary trunk less than 1 cm from the origin. The arrhythmias caused by the occlusion of the circumflex artery are due to the existence of Kugel's artery, which displays a peculiar anastomotic pattern.