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Epidemiology
Pathophysiology
Coronary artery disease is generally caused by atherosclerotic luminal narrowing, resulting in insufficient coronary blood flow to the myocardium. The process consists of subintimal atheroma deposition, leading to arterial luminal stenosis or occlusion and wall thickening.
Clinical features
Typically, significant coronary atherosclerosis becomes manifest as angina, but it can also present with anginal-equivalent symptoms, including dyspnea, dizziness, syncope, and pulmonary edema. Malignant coronary disease leading to ischemic cardiomyopathy is associated with congestive symptoms. Identified factors that contribute to severe atherosclerotic coronary artery disease include obesity, hypercholesterolemia, obesity, diabetes, tobacco use, and sedentary lifestyle.
Diagnostics
Twelve-lead electrocardiography is initially used to diagnose myocardial ischemia. Further investigation consists of exercise stress testing, evaluation of myocardial enzymes (i.e., CPK-MB, troponin), echocardiography, and coronary angiography.
Treatment
Initial medical management of acute myocardial ischemia consists of beta blockade, nitrates, anti-platelet therapy, and supplemental oxygen. After precise delineation of coronary arteriopathy, definitive treatment consists of coronary artery bypass grafting (CABG) or percutaneous angioplasty and stenting.
Outcomes/prognosis
CABG carries an overall mortality of about 3 percent; elective primary coronary bypass carries a mortality rate of approximately 1.7 percent. Complications associated with CABG include renal failure, neurologic injury, heart failure, hemorrhage, respiratory failure, and renal dysfunction. Overall, CABG achieves excellent outcomes with respect to anginal relief and resumption of normal activities. In general, completeness and durability of revascularization is superior with surgical revascularization versus percutaneous interventions.
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Coronary artery disease represents the most common cause of insufficient oxygen delivery to the myocardium, referred to as myocardial ischemia. Understanding the pathophysiology of arterial disease with subintimal atheroma and plaque formation has been a breakthrough of modern medicine. Even with our advanced understanding of heart disease, it remains the most common cause of death for Americans. Cardiovascular disease claims more lives (men and women) than cancer, trauma, and pulmonary disease combined.1
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The first coronary artery bypass grafting (CABG) operation, using saphenous vein conduit, was performed by Dr. David Sabiston at Johns Hopkins Hospital in 1962 and has evolved into the “gold standard” therapy for patients with multivessel coronary artery disease. Despite advances in percutaneous interventional techniques, CABG remains among the most frequently performed operations in the United States, associated with approximately US$50 billion in annual health care expenditures.
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Normal Coronary Anatomy and Physiology
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The right and left coronary arteries originate from the ascending aorta behind their respective aortic valve leaflets, usually in the upper third of the sinuses of Valsalva.2 By convention, the artery that supplies the posterior descending artery (PDA) determines the coronary dominance. The coronary circulation is classified as “right dominant” if the PDA is supplied by the right coronary artery and ...