cardiovascular disorders
Unstable Angina
Introduction
Unstable angina results from acute obstruction of a coronary artery without myocardial infarction. Symptoms include chest discomfort with or without dyspnea, nausea, and diaphoresis. Diagnosis is by electrocardiography (ECG) and the presence or absence of serologic markers. Treatment is with antiplatelet drugs, anticoagulants, nitrates, statins, and beta-blockers. Coronary angiography with percutaneous intervention or coronary artery bypass surgery is often necessary. (See also Overview of Acute Coronary Syndromes (ACS) .) Unstable angina is a type of Overview of Acute Coronary Syndromes (ACS) that is defined as one or more of the following in patients whose cardiac marker levels do not meet criteria for Rest Angina Pectoris that is prolonged (usually New-onset angina of at least class 3 severity in the Canadian Cardiovascular Society (CCS) classification (see table) Increasing angina, ie, previously diagnosed angina that has become distinctly more frequent, more severe, longer in duration, or lower in threshold (eg, increased by≥1 CCS class or to at least CCS class 3) Unstable angina is clinically unstable and often a prelude to myocardial infarction or Overview of Arrhythmias or, less commonly, to sudden death. 