Myocardial ischemia is one of the more common causes of chest pain in adults. Angina pectoris, or angina for short, is the term used when chest pain is thought to be attributable to myocardial ischemia. In patients with myocardial ischemia, chest pain is often but not always present, although other associated symptoms with ischemia may be present (such as exertional shortness of breath, nausea, diaphoresis, fatigue). This has been termed “silent ischemia,” although it may be more accurately termed “painless ischemia.” (See "Silent myocardial ischemia: Diagnosis".)
For those patients suspected of myocardial ischemia, timely diagnosis and treatment is necessary to reduce morbidity and mortality. Rapid diagnosis is particularly important in patients with a possible acute coronary syndrome. (See "Initial evaluation and management of suspected acute coronary syndrome in the emergency department".)
This topic will review the pathophysiology, clinical features and diagnosis of ischemic chest pain. Discussions of other cardiac and noncardiac causes of chest pain, and their clinical presentations, are found elsewhere. (See "Diagnostic approach to chest pain in adults" and "Differential diagnosis of chest pain in adults".)
PATHOPHYSIOLOGY OF MYOCARDIAL ISCHEMIA
Myocardial ischemia, and consequently angina, occurs whenever myocardial oxygen demand exceeds oxygen supply (table 1).
Myocardial oxygen demand — There are four major factors that determine myocardial work and therefore myocardial oxygen demand: