What is Angina Pectoris?
Angina pectoris is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, or arms that is typically triggered by exertion or emotional stress and relieved by rest or nitroglycerin, representing a symptom of myocardial ischemia (inadequate oxygen supply to the heart muscle). 1, 2
Core Clinical Features
The discomfort of angina pectoris has four defining characteristics that help distinguish it from other causes of chest pain:
Location
- Usually retrosternal (behind the breastbone) but can radiate to:
- Jaw or teeth
- Shoulder blades
- Either arm extending to wrist and fingers
- Neck
- Upper abdomen (epigastric area)
- Back 2
Character of Discomfort
The sensation is typically described as:
- Pressure, tightness, or heaviness
- Strangling or constricting feeling
- Burning sensation
- Not sharp, stabbing, or fleeting pain 2
Duration and Triggers
- Brief episodes, typically not more than 10 minutes, often less
- Provoked by physical exertion (walking uphill, climbing stairs)
- Triggered by emotional stress
- Worsened by cold weather, wind, or heavy meals
- Often worse in the morning 2
Relief Pattern
- Rapidly disappears within minutes when triggering factors stop
- Relieved by rest
- Responds quickly to sublingual or buccal nitroglycerin 1, 2
Types of Angina
Angina is classified into distinct categories based on pattern and severity 3:
Stable Angina
- Predictable pattern without recent change in frequency
- Relieved by rest and/or sublingual/transdermal medications
- Represents chronic myocardial ischemia 3
Unstable Angina
- Rest angina (prolonged, usually >20 minutes)
- New-onset severe angina (CCS Class III or IV)
- Crescendo pattern with increasing severity
- This is a medical emergency requiring immediate evaluation 1, 3
Variant Angina (Prinzmetal Angina)
- Occurs spontaneously, typically at rest
- Does not require physical exertion
- Associated with coronary vasospasm
- Often shows transient ST-segment elevation on ECG 3
Associated Symptoms
Beyond chest discomfort, patients may experience:
- Shortness of breath (dyspnea)
- Fatigue or weakness
- Nausea or vomiting
- Sweating
- Sense of impending doom
- Burping or restlessness 2
Important caveat: Women, elderly patients, and those with diabetes may present with atypical symptoms or predominantly experience associated symptoms rather than classic chest pain 4, 5.
Underlying Pathophysiology
Angina pectoris results from myocardial ischemia—an imbalance between oxygen supply and demand in the heart muscle 6, 7. While atherosclerotic coronary artery disease is the most common cause, angina can also result from:
- Coronary microvascular dysfunction
- Coronary vasospasm
- Hypertrophic cardiomyopathy
- Aortic stenosis
- Other conditions affecting myocardial oxygen delivery 2
Severity Grading
The Canadian Cardiovascular Society (CCS) grading scale classifies angina severity 3:
- Class I: Angina only with strenuous/prolonged exertion
- Class II: Slight limitation; angina with rapid walking, climbing stairs, or stress
- Class III: Marked limitation; angina walking 1-2 blocks or climbing one flight of stairs
- Class IV: Inability to perform any activity without discomfort; symptoms may occur at rest
Clinical Significance
Approximately 11.1 million Americans have chronic stable angina, with over 400,000-500,000 new cases diagnosed annually 8, 6, 9. Angina itself is a predictor of major adverse cardiac events and significantly impairs quality of life, warranting comprehensive evaluation and treatment 6.
Key Distinction
Angina is not a disease but a symptom—specifically, it signals that the heart muscle is not receiving adequate oxygen. The term should be confined to cases where symptoms can be attributed to myocardial ischemia, though similar symptoms can arise from esophageal, pulmonary, or chest wall disorders 2.