Heart Encyclopedia

In-depth clinical insights and data-driven intelligence on major cardiovascular conditions.

Coronary Artery Disease

Pathophysiology of CAD

Coronary artery disease (CAD) develops when the major blood vessels that supply the heart become damaged or diseased. Cholesterol-containing deposits (plaque) in the coronary arteries and inflammation are usually the primary culprits. When plaque builds up, it narrows the coronary arteries, decreasing blood flow to the heart. Eventually, the reduced blood flow may cause chest pain (angina), shortness of breath, or other coronary artery disease signs and symptoms. A complete blockage can cause a heart attack.

CAD often develops over decades. Symptoms might not be noticed until there is a significant blockage or a heart attack. Taking a heart-healthy lifestyle approach can make a huge impact on preventing the progression of this disease.

Diagnostic Insight

Clinical detection often involves Stress Testing, CT Angiography, or Cardiac Catheterization to visualize the extent of arterial stenosis (narrowing).

Clinical Risk Factors

• Hypercholesterolemia (High LDL)
• Chronic Hypertension
• Type 2 Diabetes Mellitus
• Tobacco Use & Vaping
• Sedentary Lifestyle
• Advanced Biological Age

Cardiac Arrhythmia

Electrical System Failures

A heart arrhythmia is an irregular heartbeat. Heart rhythm problems occur when the electrical impulses that coordinate your heartbeats don't work properly, causing your heart to beat too fast, too slow or irregularly. Heart arrhythmias may feel like a fluttering or racing heart and are often harmless. However, some heart arrhythmias may cause bothersome — sometimes even life-threatening — signs and symptoms.

Common types include Atrial Fibrillation (AFib), which is a rapid, uncoordinated heart rate, and Bradycardia, where the heart beats too slowly to provide enough oxygen-rich blood to the body.

Diagnostic Insight

Standard detection uses Electrocardiograms (ECG/EKG), Holter monitors (wearable ECG), or Event recorders to capture the irregular electrical patterns.

Primary Symptoms

• Palpitations (Racing Heart)
• Lightheadedness or Syncope
• Chest Discomfort
• Profound Weakness
• Shortness of Breath

Congestive Heart Failure

The Inability to Pump

Heart failure, sometimes known as congestive heart failure, occurs when the heart muscle doesn't pump blood as well as it should. When this happens, blood often backs up and fluid can build up in the lungs, causing shortness of breath. Certain heart conditions, such as narrowed arteries in the heart (coronary artery disease) or high blood pressure, gradually leave the heart too weak or stiff to fill and pump blood properly.

Heart failure can be ongoing (chronic), or it may start suddenly (acute). Treatment can improve the signs and symptoms of heart failure and may help you live longer. Lifestyle changes — such as losing weight, exercising, reducing salt in your diet and managing stress — can improve your quality of life.

Diagnostic Insight

Echocardiograms are the primary tool to measure Ejection Fraction (EF), which determines how much blood the heart pumps out with each contraction.

Stage Indicators

• Peripheral Edema (Swelling)
• Reduced Exercise Tolerance
• Persistent Nocturnal Cough
• Rapid or Irregular Pulse
• Abdominal Swelling (Ascites)

Cardiomyopathy

Structural Muscle Abnormalities

Cardiomyopathy is a disease of the heart muscle that makes it harder for the heart to pump blood to the rest of the body. Cardiomyopathy can lead to heart failure. The main types of cardiomyopathy include dilated, hypertrophic and restrictive cardiomyopathy. Treatment — which might include medications, surgically implanted devices, heart surgery or, in severe cases, a heart transplant — depends on the type of cardiomyopathy and how serious it is.

As cardiomyopathy worsens, the heart becomes weaker. It's less able to pump blood through the body and maintain a normal electrical rhythm. This can lead to heart failure or an irregular heartbeat (arrhythmia).

Diagnostic Insight

Cardiac MRI and Genetic testing are often utilized to differentiate between the various types of cardiomyopathy and determine hereditary risks.

Hereditary & Acquired Risks

• Family History of Heart Disease
• Long-term High Blood Pressure
• Heart Valve Problems
• Prior Heart Attack Damage
• Chronic Rapid Heart Rate

Myocardial Infarction

Acute Ischemic Events

A heart attack (myocardial infarction) happens when the flow of blood to the heart is severely reduced or blocked. The blockage is usually due to a buildup of fat, cholesterol and other substances in the heart (coronary) arteries. These fatty, cholesterol-containing deposits are called plaques. The process of plaque buildup is called atherosclerosis. Sometimes, a plaque can rupture and form a clot that blocks blood flow. A lack of blood flow can damage or destroy part of the heart muscle.

A heart attack is a medical emergency. If you think you're having a heart attack, call 911 or your local emergency number immediately. The sooner you get treatment, the better your chances of survival and recovery.

Diagnostic Insight

Emergency Troponin blood tests and an immediate ECG are the "gold standard" for diagnosing an active heart attack in a clinical setting.

Emergency Red Flags

• Crushing Chest Pressure
• Pain Radiating to Jaw/Arm
• Cold Sweats & Nausea
• Impending Sense of Doom
• Sudden Severe Fatigue