Angina: Symptoms, Types, Causes and Treatment

Angina pectoris, commonly referred to simply as angina, is a clinical syndrome characterized by discomfort or pain in the chest due to insufficient blood supply to the heart muscle. It is a warning sign of underlying heart issues, most notably coronary artery disease, and can have a significant impact on a person's daily life. Understanding the symptoms, types, causes, and available treatments of angina is crucial for effective management and improved quality of life. This comprehensive guide explores each facet of angina with the latest research and clinical consensus.

Symptoms of Angina

Angina symptoms are often stereotypical, but they can vary widely among individuals, sometimes presenting in subtle or atypical ways. Recognizing these symptoms promptly is vital for early intervention and prevention of serious cardiac events.

Symptom	Description	Typicality (Men/Women)	Source(s)
Chest pain	Pressure, tightness, or burning in the chest; may radiate to neck, jaw, or arm	More typical in men; women may have less typical pain	1 3
Shortness of breath	Feeling of not getting enough air, especially during exertion	Common in both; more frequent in women	1 2
Nausea	Feeling sick to the stomach	More often in women	1
Weakness	Unusual fatigue or lack of energy	More often in women	1 2
Back/neck pain	Pain in upper back, neck, or jaw	More common in women	1
Sweating	Cold, clammy sweat	Both sexes	2 3
Palpitations	Awareness of heart beating	Sometimes present	2

Table 1: Key Symptoms of Angina

Typical vs. Atypical Symptoms

• Typical angina presents as chest pain or discomfort, often described as a pressure or squeezing sensation behind the breastbone. This may radiate to the left arm, neck, jaw, or back, especially during physical exertion or emotional stress. The pain usually subsides with rest or nitroglycerin 3 8.
• Atypical symptoms are more common in women and may include:
  • Shortness of breath
  • Fatigue or weakness
  • Nausea or loss of appetite
  • Upper back or jaw pain
  • “Stabbing” or “knifelike” sensations rather than pressure 1

Symptom Variation by Sex

Research shows that while classic chest pain is common in both sexes, women are more likely to have less typical symptoms, including:

• Shortness of breath (74% in women vs. 60% in men)
• Weakness (74% in women vs. 48% in men)
• Nausea and loss of appetite
• Upper back pain and stabbing or knifelike pain 1

Emotional and Psychological Symptoms

• Anxiety, irritability, and depression frequently accompany angina, especially in those experiencing frequent episodes or significant lifestyle limitations 2.
• Fatigue and sleep disturbances are also common and can worsen quality of life 2.

Recognizing Angina

It’s important to note that not all chest pain is angina, and not all angina presents as chest pain. Some patients—especially women, older adults, and those with diabetes—may have silent or atypical symptoms. Prompt recognition and assessment by healthcare providers are essential for proper diagnosis and management.

Types of Angina

Angina is not a one-size-fits-all condition. Its clinical presentation can differ based on the underlying mechanism, triggers, and predictability of symptoms. Understanding these variants helps tailor treatment and risk management.

Type	Description	Key Triggers/Features	Source(s)
Stable	Predictable, occurs with exertion or stress	Relieved by rest/nitroglycerin	3 12
Unstable	New, worsening, or at rest; unpredictable	Higher risk, may precede heart attack	1 4
Variant (Prinzmetal)	Occurs at rest, caused by coronary spasm	Transient ST-segment elevation	4 6
Microvascular	Chest pain with normal coronary arteries	More common in women, exertional or at rest	6 7 9
Mixed	Both exertion and rest episodes	Combination of triggers	5

Table 2: Types of Angina

Stable Angina

• Definition: Predictable chest pain or discomfort that occurs with physical exertion or emotional stress and is relieved by rest or nitroglycerin.
• Pattern: Symptoms remain stable over time, appearing at a certain level of activity and resolving with rest 3 12.
• Clinical significance: Indicates underlying coronary artery disease but is generally less immediately dangerous than unstable forms.

Unstable Angina

• Definition: New onset, worsening, or pain occurring at rest; unpredictable and more severe.
• Risk: Signals a higher risk of heart attack (myocardial infarction) and requires urgent medical evaluation 1 4.
• Features: Symptoms may not fully resolve with rest or nitroglycerin.

Variant Angina (Prinzmetal’s)

• Definition: Episodic, often severe chest pain, usually at rest, caused by spasms of the coronary arteries.
• Diagnostic clue: Transient ST-segment elevation during pain episodes 4 6.
• Triggers: Often unrelated to exertion; can occur at night or early morning.

Microvascular Angina

• Definition: Angina-like symptoms with evidence of myocardial ischemia but normal or near-normal coronary arteries on angiography.
• Population: More common in women and can occur during exertion or at rest 6 7 9.
• Mechanism: Dysfunction or spasm of small coronary vessels (microcirculation).

Mixed Angina

• Definition: Patients experience both predictable (exertional) and unpredictable (rest) angina episodes.
• Complexity: Reflects both supply and demand issues in the heart’s oxygen balance 5.

Causes of Angina

Understanding the root causes of angina is fundamental for prevention and targeted therapy. Angina arises when the heart muscle doesn't receive enough oxygen-rich blood, usually due to narrowed or dysfunctional blood vessels.

Cause	Mechanism	Common Types Affected	Source(s)
Coronary artery disease (CAD)	Obstructive atherosclerotic plaques	Stable, Unstable, Mixed	3 4 8 10
Coronary artery spasm	Sudden narrowing/constriction of artery	Variant (Prinzmetal’s)	4 6
Microvascular dysfunction	Abnormal vessel dilation/constriction	Microvascular, Mixed	6 7 9
Thrombus formation	Non-occlusive blood clot on a plaque	Unstable	4
Increased oxygen demand	Fever, tachycardia, hypertension, etc.	Stable, Mixed	8 10

Table 3: Major Causes of Angina

Coronary Artery Disease (CAD)

• Pathophysiology: The most common cause of angina. Plaques made up of cholesterol and other substances build up in the coronary arteries, restricting blood flow to the myocardium 3 8 10.
• Stable angina typically results from fixed, partial blockages.
• Unstable angina often involves a sudden change, such as plaque rupture and the formation of a non-occlusive thrombus, which further reduces blood flow and increases risk 4.

Coronary Artery Spasm

• Mechanism: Transient, intense constriction of an epicardial coronary artery (not necessarily at the site of atherosclerotic plaque) 4 6.
• Result: Sudden reduction in blood flow, leading to variant (Prinzmetal’s) angina.

Microvascular Dysfunction

• Description: The small vessels (microvasculature) within the heart fail to dilate properly or go into spasm, limiting blood delivery even when major arteries are clear 6 7 9.
• Associated with: Women, those with persistent symptoms after revascularization, and some forms of cardiomyopathy.

Thrombus Formation

• Role: In unstable angina, small blood clots develop on disrupted plaques, partially blocking blood flow. These can grow or break loose, potentially causing heart attacks 4.

Increased Oxygen Demand

• Triggers: Conditions that increase the heart’s workload can precipitate angina, especially if underlying blockages exist. Common examples include:
  • Physical exertion
  • Emotional stress
  • Fever
  • Accelerated heart rate (tachycardia)
  • Hypertension 8 10

Treatment of Angina

Managing angina involves both relieving symptoms and reducing the risk of heart attack or death. Treatment is individualized, taking into account the type of angina, underlying causes, comorbidities, and patient preferences.

Treatment	Purpose/Action	Typical Indication	Source(s)
Beta-blockers	Lower heart rate, reduce demand	First-line for stable angina	12 13 14
Calcium channel blockers	Vasodilation, reduce workload	Alternative or adjunct to beta-blockers	12 13 14
Nitrates	Dilate blood vessels, relieve pain	Acute and chronic symptom relief	12 13 14
Second-line agents	Metabolic/other effects	For refractory symptoms	13 14 15
Antiplatelet therapy	Prevent clot formation	Especially unstable angina	4 12
Lifestyle modification	Address risk factors	All types	12 14
Revascularization	Restore blood flow	Severe/refractory cases	12 14
Adjunctive therapies (e.g., acupuncture)	Symptom reduction, quality of life	Select patients	11

Table 4: Main Treatments for Angina

First-Line Medications

• Beta-blockers: Lower heart rate and reduce myocardial oxygen demand. Shown to reduce cardiac events and improve survival, especially post-heart attack. Generally first-line unless contraindicated 12 13 14.
• Calcium channel blockers: Promote vasodilation and reduce heart workload. Useful if beta-blockers are not tolerated or insufficient 12 13.
• Short-acting nitrates: Provide rapid relief of acute angina attacks; all patients should be prescribed sublingual nitroglycerin for on-demand use 12 13 14.

Second-Line and Adjunctive Agents

• Long-acting nitrates, ivabradine, nicorandil, ranolazine, trimetazidine: Used when symptoms persist despite first-line therapy or in those with contraindications 13 14 15.
  • Trimetazidine: Modifies cardiac metabolism without affecting heart rate or blood pressure, beneficial as an add-on or in special populations (e.g., diabetics, those with left ventricular dysfunction) 15.
• Antiplatelet therapy: Essential in unstable angina to prevent clot progression (e.g., aspirin, ticlopidine, glycoprotein IIb/IIIa inhibitors) 4 12.

Non-Drug Therapies

• Lifestyle modifications: Smoking cessation, healthy diet, weight control, regular physical activity, and management of hypertension, diabetes, and cholesterol are crucial 12 14.
• Revascularization: Procedures such as percutaneous coronary intervention (angioplasty/stenting) or coronary artery bypass grafting may be required for severe or refractory angina 12 14.
• Adjunctive therapies: Techniques like acupuncture have shown some benefit in reducing angina attacks when combined with standard therapy 11.

Personalized Approach

• No single antianginal medication has proven superior in head-to-head trials; therapy is often tailored to the individual, and combination therapy is common 13 14.
• Selection of treatment takes into account comorbidities, side effect profiles, patient preferences, and underlying mechanisms (e.g., avoiding beta-blockers in vasospastic angina) 14.

Conclusion

Angina is a complex clinical syndrome with diverse symptoms, causes, and treatment options. Early recognition and individualized management are key to improving outcomes and quality of life.

Key Points:

• Angina symptoms vary, with women often experiencing atypical presentations such as shortness of breath, fatigue, or back pain 1.
• The major types of angina include stable, unstable, variant (Prinzmetal’s), microvascular, and mixed forms, each with distinct features and triggers 3 4 6 7 9.
• The primary causes of angina are obstructive coronary artery disease, coronary artery spasm, microvascular dysfunction, thrombus formation, and increased cardiac demand 3 4 6 7 8 10.
• Management includes medications (beta-blockers, calcium channel blockers, nitrates, second-line agents), lifestyle changes, antiplatelet therapy, and sometimes revascularization 12 13 14 15.
• No single therapy is superior for all patients; treatment should be individualized, often requiring combination therapy and consideration of comorbidities 13 14 15.
• Adjunctive therapies such as acupuncture may help reduce symptom frequency and improve quality of life for some patients 11.

Empowering patients and clinicians with knowledge of angina’s nuances supports timely diagnosis, effective treatment, and better long-term outcomes.