Coronary Artery Disease (CAD), also called Coronary Artery Disorders, is the leading cause of death worldwide. It occurs when the coronary arteries, which supply blood and oxygen to the heart muscle, become narrowed or blocked due to atherosclerosis—the buildup of fatty plaques inside the arterial walls. This restriction of blood flow leads to ischemia (reduced oxygen supply), which can result in angina pectoris (chest pain), myocardial infarction (heart attack), or even death.
Understanding CAD is critical for both prevention and management, especially since many of its risk factors are modifiable through lifestyle changes and medical intervention.
Pathophysiology of Coronary Artery Disease
Normal artery: Coronary arteries are elastic tubes that deliver oxygen-rich blood to the heart.Key Point: CAD is a progressive disease that develops silently over years before symptoms appear.
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Risk Factors for CAD
CAD risk factors are classified into non-modifiable and modifiable categories.
Non-Modifiable Risk Factors
Age: Risk increases after age 45 in men and 55 in women.Modifiable Risk Factors
- Diabetes mellitus
- Hypertension (high blood pressure)
- Smoking
- Obesity
- Physical inactivity
- High cholesterol (LDL, triglycerides)
- Metabolic syndrome
Insight: While you can’t change your genetics or age, you can significantly reduce CAD risk by modifying lifestyle-related factors.
Signs and Symptoms of CAD
CAD often remains asymptomatic until significant narrowing occurs. Symptoms arise due to ischemia (reduced oxygen supply) to the myocardium.
Myocardial Ischemia
Definition: Reduced oxygen delivery to the heart muscle.Symptoms:
- Chest discomfort or pain
- Fatigue
- Shortness of breath
Angina Pectoris
Definition: Chest pain caused by myocardial ischemia.Types:
- Stable angina: Triggered by activity, relieved by rest.
- Unstable angina: Occurs at rest, warning sign of an impending heart attack.
Symptoms:
- Chest pain/pressure (radiating to jaw, neck, arm, or back)
- Dyspnea (shortness of breath)
- Fatigue, sweating, nausea
Myocardial Infarction (Heart Attack)
Definition: Complete blockage of coronary artery leading to myocardial cell death.Symptoms:
- Severe, crushing chest pain
- Pain unrelieved by rest or nitroglycerin
- Cold sweats, dizziness, loss of consciousness
Key Point: Ischemia = ↓ O₂; Infarction = Death of myocardial cells
Diagnosis of CAD
1. Blood Tests – Lipid Profile
LDL (Low-Density Lipoprotein): “Bad cholesterol” – promotes plaque buildup.
- Desired level: <100 mg/dL
HDL (High-Density Lipoprotein): “Good cholesterol” – removes cholesterol from blood vessels.
- Desired level: >60 mg/dL
2. Electrocardiogram (ECG)
- Detects electrical changes in the heart.
- Key findings: ST-segment or T-wave changes suggesting ischemia or infarction.
3. Additional Diagnostic Tests (not in the chart but clinically relevant)
- Echocardiogram – evaluates heart structure and function.
- Stress test – monitors ECG changes during exercise.
- Coronary angiography – visualizes coronary artery blockages.
Treatment of CAD
Management of CAD focuses on relieving symptoms, preventing progression, and reducing complications.
1. Lifestyle and Non-Pharmacological Interventions
Heart-healthy diet: Low sodium, low fat, high fiber.Regular physical activity:
- 75 minutes of moderate-intensity OR
- 150 minutes of vigorous-intensity weekly.
2. Medications
- Statins: Lower LDL cholesterol.
- Antihypertensives: Beta-blockers, ACE inhibitors, ARBs.
- Antiplatelets (Aspirin, Clopidogrel): Reduce clot formation.
- Nitrates: Relieve angina.
3. Surgical Interventions
- Coronary Stent/Angioplasty: Opens narrowed arteries using a balloon and stent.
- Coronary Artery Bypass Graft (CABG): Uses grafts to reroute blood flow around blockages.
Prevention of CAD
Prevention strategies can delay or stop the progression of CAD:
- Control hypertension and diabetes
- Quit smoking
- Follow a balanced diet (rich in fruits, vegetables, omega-3 fatty acids)
- Exercise regularly
- Maintain healthy weight
- Get routine check-ups for cholesterol and blood pressure
Comparative Table: LDL vs HDL
| Type of Cholesterol | Full Form | Nickname | Desired Level | Effect on Heart Health |
|---|---|---|---|---|
| LDL | Low-Density Lipoprotein | “Bad cholesterol” | <100 mg/dL | Deposits fat in arteries → Atherosclerosis |
| HDL | High-Density Lipoprotein | “Good cholesterol” | >60 mg/dL | Removes cholesterol from arteries → Protective |
Conclusion
Coronary Artery Disease (CAD) is a preventable yet life-threatening condition. By identifying risk factors early, making lifestyle modifications, undergoing regular screenings, and following appropriate treatments, individuals can significantly reduce their risk of heart attack and complications.
The message is clear: lower LDL, raise HDL, exercise regularly, eat heart-healthy, and quit smoking.
FAQs on Coronary Artery Disease
Q1: What is the main cause of CAD?
The buildup of fatty plaques in coronary arteries (atherosclerosis) is the primary cause.
Q2: How is CAD different from a heart attack?
CAD is the underlying disease (blocked arteries), while a heart attack is the acute complication when blood flow is completely cut off.
Q3: Can CAD be reversed?
Plaques cannot be fully reversed, but progression can be slowed or stabilized with medication and lifestyle changes.
Q4: What is the best diet for CAD prevention?
The Mediterranean diet (rich in olive oil, nuts, whole grains, vegetables, and fish) is considered one of the most heart-protective.
Q5: Is CAD hereditary?
Yes, family history increases risk, but lifestyle interventions can still greatly reduce the chances of developing CAD.
