Coronary Artery Disease (CAD): Understanding the Leading Cause of Heart Attacks
Coronary Artery Disease (CAD) is one of the most common cardiovascular conditions and a leading cause of heart attacks and chest pain worldwide. This condition develops when the coronary arteries — the vessels that supply blood and oxygen to the heart muscle — become narrowed or blocked by fatty deposits called plaques, a process known as atherosclerosis.
CAD affects millions globally and is a leading cause of morbidity and mortality. Understanding its pathophysiology is crucial for healthcare professionals and essential for NCLEX success.
Key Terms You Must Know
CAD Terminology at a Glance
Atherosclerosis
- Buildup of fatty plaques in the arterial walls — the primary underlying cause of CAD. Develops slowly over years through inflammation and lipid deposition in arterial walls.
Angina
- Chest pain or discomfort due to reduced oxygen supply to the heart muscle (ischemia). Can be stable (predictable with exertion) or unstable (unpredictable and dangerous).
Myocardial Infarction (MI)
- Heart attack resulting from complete blockage of blood flow to a portion of the heart. Causes irreversible cardiac tissue death if not treated promptly.
Acute Coronary Syndrome (ACS)
- Umbrella term that includes unstable angina, NSTEMI, and STEMI. All involve reduced coronary blood flow and require urgent medical management.
Risk Factors for CAD
Modifiable risk factors account for up to 90% of CAD cases. Lifestyle interventions can significantly reduce the burden of heart disease.
Modifiable vs. Non-Modifiable Risk Factors
Modifiable Risk Factors
- Smoking — damages arterial walls and accelerates plaque formation
- Hypertension — strains the heart and damages arterial walls
- High LDL Cholesterol — directly contributes to plaque buildup
- Diabetes — damages blood vessels and accelerates atherosclerosis
- Obesity and Sedentary Lifestyle — increases blood pressure and cholesterol
- Metabolic Syndrome — cluster of high BP, blood sugar, abdominal fat, and abnormal cholesterol
Non-Modifiable Risk Factors
- Family history and genetics — genetic predisposition increases risk independent of lifestyle
- Age — risk increases significantly with age (men over 45, women over 55)
- Sex — men are at higher risk earlier; women's risk rises after menopause
Signs and Symptoms
CAD symptoms can vary significantly between individuals and may be absent in some cases — this is called silent ischemia, and is particularly common in patients with diabetes.
Classic Signs and Symptoms of CAD
- Chest Pain (Angina): — Pressure, squeezing, or burning sensation that may radiate to the arm, jaw, neck, or back
- Shortness of Breath: — Especially during physical exertion — often accompanies chest discomfort
- Fatigue: — Unusual tiredness during physical activity — a common early and frequently overlooked symptom
- Dizziness and Palpitations: — May occur in more advanced stages of the disease
- Cold Sweats (Diaphoresis): — Often accompanies chest discomfort during ischemic episodes
Recognizing Atypical CAD Presentations
Women, diabetic patients, and elderly individuals often present with atypical symptoms — jaw pain, epigastric discomfort, unusual fatigue, or nausea — rather than classic chest pain. These atypical presentations are frequently tested on the NCLEX and must be recognized to avoid delayed or missed treatment.
Diagnosis
Diagnostic Approach for CAD
- Electrocardiogram (ECG/EKG): Records electrical activity of the heart; detects ischemic changes, ST depression or elevation, and arrhythmias
- Blood Tests: Lipid profile for cholesterol levels; cardiac enzymes (troponin, CK-MB) to detect myocardial cell damage
- Stress Tests: Exercise treadmill or pharmacological stress test to evaluate heart function under increased oxygen demand
- Echocardiogram: Ultrasound imaging to assess heart wall motion, valve function, and ejection fraction
- Coronary Angiography: Gold standard — contrast dye imaging to directly visualize the location and severity of blockages in coronary arteries
Treatment Approaches
CAD Treatment: Lifestyle, Medications, and Procedures
Lifestyle Modifications
- Heart-healthy diet low in saturated fats (Mediterranean-style)
- Regular aerobic exercise (150 minutes per week at moderate intensity)
- Smoking cessation — the single most impactful modifiable change
- Weight management and stress reduction techniques
Medications
- Antiplatelets (aspirin) — prevent clot formation on plaques
- Statins — lower LDL cholesterol and stabilize plaques
- ACE inhibitors and beta-blockers — manage blood pressure and cardiac workload
- Nitrates — relieve angina through vasodilation
Procedures
- Percutaneous Coronary Intervention (PCI) — angioplasty with stent placement to open blocked arteries
- Coronary Artery Bypass Graft (CABG) — surgical rerouting of blood flow around blocked arteries
Key Takeaways: Coronary Artery Disease
- CAD develops from atherosclerosis — progressive fatty plaque buildup in the coronary arteries
- Modifiable risk factors account for approximately 90% of CAD cases — lifestyle changes save lives
- Classic symptom is chest pressure or squeezing that may radiate to the arm, jaw, or back
- Women, diabetics, and elderly patients often present atypically — fatigue, jaw pain, or nausea
- Troponin is the most specific cardiac biomarker for diagnosing myocardial infarction
- Treatment includes lifestyle modifications, medications (aspirin, statins), PCI, and CABG
- Prevention through management of modifiable risk factors is the most effective long-term strategy