Coronary Artery Disease Overview

Study Notes

Coronary Artery Disease (CAD)

A condition where coronary arteries narrow or become blocked, usually due to atherosclerosis (plaque buildup)
Restricts blood flow to the heart muscle, potentially leading to chest pain (angina), heart attacks, and other complications.

Types of CAD

Obstructive Coronary Artery Disease: Plaque buildup narrows coronary arteries, the most common type
Nonobstructive Coronary Artery Disease: Narrowing caused by conditions besides plaque buildup, such as:
- Irregular constrictions (coronary vasospasm)
- Heart tissue compressing coronary arteries (myocardial bridging)
- Damage to artery lining (endothelial dysfunction)
Spontaneous Coronary Artery Dissection (SCAD): A sudden tear in the coronary artery wall blocks blood flow, often presenting as a heart attack

Signs and Symptoms

Chest pain (angina), fullness, or pressure
Fatigue
Heart palpitations, or rapid heartbeat sensations
Shortness of breath (dyspnea)
Swelling in hands or feet

Pathophysiology

Central adiposity: Increased fat storage in the abdomen, leading to:
- Increased fasting blood glucose
- Production of adipokines by adipose cells
Metabolic Syndrome:
- Insulin resistance
- Increased fasting blood glucose
- Dyslipidemia (abnormal blood lipid levels)
- Hypertension
- Chronic inflammation
Direct atherogenic effects: Directly contribute to the formation of atherosclerosis
Atherosclerosis: Plaque builds up in the arteries, narrowing them.

Medical Management

Risk Factor Control: Manage underlying conditions like hypertension, diabetes mellitus, and hyperlipidemia.
Lifestyle Modifications:
- Smoking cessation
- Regular physical activity (at least 150 minutes of moderate-intensity exercise per week)
- Healthy diet (low in saturated fats, trans fats, cholesterol, and salt; high in fruits, vegetables, whole grains, and lean proteins)
- Weight management

Procedures

Electrocardiogram (ECG): Detects ischemic changes, arrhythmias, previous myocardial infarctions, or ongoing ischemia. May show ST-segment changes, T-wave inversions, or Q waves indicative of CAD.
Echocardiography (Stress Echocardiogram): Evaluates heart structure and function, helps assess underlying conditions.
Nuclear Stress Test (Myocardial Perfusion Imaging): Involves injecting a radioactive tracer to assess blood flow to the heart muscle, identifying areas of reduced perfusion suggesting CAD.
Coronary CT Angiography (CCTA): Non-invasive imaging technique using computed tomography (CT) to visualize coronary arteries, detecting the presence of plaques, stenosis, and anatomical anomalies.
Cardiac Magnetic Resonance Imaging (MRI): Non-invasive imaging method providing detailed information about heart muscle viability, perfusion, and anatomy. Stress cardiac MRI can be used to evaluate myocardial ischemia and scarring.
Coronary Angiography (Cardiac Catheterization): Considered the "gold standard" for diagnosing CAD. Involves inserting a catheter into the coronary arteries to visualize them under X-ray, providing direct visualization of coronary artery anatomy, the location and severity of stenosis, and other abnormalities. If significant stenosis is found, interventions like percutaneous coronary intervention (PCI) with stenting may be performed during the same procedure.
Intravascular Ultrasound (IVUS): High-frequency sound waves to create images of the inside of coronary arteries. Used to determine the extent of plaque buildup, the thickness of artery walls, and the effectiveness of stenting.