Stable<unk>  Also known as 'effort<unk> ', this refers to the classic type of<unk>  related to myocardial ischemia. A typical presentation of stable<unk>  is that of chest discomfort and associated symptoms precipitated by some activity (running, walking, etc.) with minimal or non-existent symptoms at rest or after administration of sublingual nitroglycerin. Symptoms typically abate several minutes after activity and recur when activity resumes. In this way, stable<unk>  may be thought of as being similar to intermittent claudication symptoms. Other recognized precipitants of stable<unk>  include cold weather, heavy meals, and emotional stress. Unstable<unk>  Unstable<unk>  (UA) (also "crescendo<unk> "; this is a form of acute coronary syndrome) is defined as<unk>  pectoris that changes or worsens. It has at least one of these three features: # it occurs at rest (or with minimal exertion), usually lasting more than 10 minutes # it is severe and of new-onset (i.e., within the prior 4–6 weeks) # it occurs with a crescendo pattern (i.e., distinctly more severe, prolonged, or frequent than before). UA may occur unpredictably at rest, which may be a serious indicator of an impending heart attack. What differentiates stable<unk>  from unstable<unk>  (other than symptoms) is the pathophysiology of the atherosclerosis. The pathophysiology of unstable<unk>  is the reduction of coronary flow due to transient platelet aggregation on apparently normal endothelium, coronary artery spasms, or coronary thrombosis. The process starts with atherosclerosis, progresses through inflammation to yield an active unstable plaque, which undergoes thrombosis and results in acute myocardial ischemia, which, if not reversed, results in cell necrosis (infarction). Studies show that 64% of all unstable<unk> s occur between 22:00 and 08:00 when patients are at rest. In stable<unk> , the developing atheroma is protected with a fibrous cap. This cap may rupture in unstable<unk> , allowing blood clots to precipitate and further decrease the area of the coronary vessel's lumen. This explains why, in many cases, unstable<unk>  develops independently of activity. Cardiac syndrome X Cardiac syndrome X, sometimes known as microvascular<unk>  is characterized by<unk> -like chest pain, in the context of normal epicardial coronary arteries (the largest vessels on the surface of the heart, prior to significant branching) on angiography. The original definition of cardiac syndrome X also mandated that ischemic changes on exercise (despite normal coronary arteries) were displayed, as shown on cardiac stress tests. The primary cause of cardiac syndrome X is unknown, but factors apparently involved are endothelial dysfunction and reduced flow (perhaps due to spasm) in the tiny "resistance" blood vessels of the heart. Since microvascular<unk>  is not characterized by major arterial blockages, it is harder to recognize and diagnose. Microvascular<unk>  was previously considered a rather benign condition, but more recent data has changed this attitude. Studies, including the Women's Ischemia Syndrome Evaluation (WISE), suggest that microvascular<unk>  is part of the pathophysiology of ischemic heart disease, perhaps explaining the higher rates of<unk>  in women than in men, as well as their predilection towards ischemia and acute coronary syndromes in the absence of obstructive coronary artery disease.
Angina
Gastroesophageal reflux disease
Chest pain
Heartburn
Carditis
Shingles
Abdominal angina
Cholecystitis