2.4 - Diseases of the Cardiovascular System

Cardiac muscle cell repair capability

Damaged cardiac muscle cells have extremely limited abilities to repair themselves or replace dead cells via mitosis; newly formed or repaired cells are rarely as functional as the originals, so cardiac function is typically reduced after damage

Cardiac stem cells

At least some stem cells remain within the heart that continue to divide and potentially replace dead cardiac cells

Myocardial infarction cell replacement

Following a heart attack, dead cardiac cells are often replaced by patches of scar tissue

Coronary artery disease (CAD)

Narrowing or blockage of the coronary arteries due to atherosclerosis, which restricts blood flow to the heart

Atherosclerosis

A chronic condition characterized by the accumulation of fatty deposits, cholesterol, and other substances in arterial walls, leading to narrowed and hardened arteries that impair blood flow and increase cardiovascular disease risk

Cholesterol (cardiovascular relevance)

A type of fat in the blood; high levels contribute to atherosclerosis

Ischemia

Insufficient blood supply to an organ or part of the body, often due to a blockage in an artery

Myocardial infarction (heart attack)

Occurs when a portion of the heart muscle dies because of a lack of oxygen due to a blockage in a coronary vessel

Angina pectoris (CAD context)

Chest pain suffered when a coronary artery is partially blocked due to plaque, often characterized by radiating pain in the left arm

Common heart attack symptoms

Shortness of breath, pain or pressure over the chest, pain/pressure/fullness or squeezing in the arms, back, jaw, neck, or between the shoulders, lightheadedness, cold sweat, and upset stomach or urge to vomit

Additional heart attack signs in women

Some women may feel very tired for days or weeks before a heart attack, and may experience heartburn, a cough, heart flutters, or loss of appetite

Heart failure

A condition where the heart is unable to pump blood effectively, causing fluid buildup, fatigue, and shortness of breath

Arrhythmias

Irregular heart rhythms that can range from benign to life-threatening

Palpitations

A symptom of arrhythmia resulting in the sensation of a skipped or added heartbeat, which can cause dizziness, lightheadedness, or fainting; generally not life-threatening unless persistent or severe

Bradycardia (disease definition)

An abnormally slow heart rate, typically below 60 beats per minute in adults; may be normal in athletes, but can also indicate an underlying problem such as electrical system issues or heart disease

Bradycardia symptoms

Dizziness, fainting, fatigue, shortness of breath, or chest pain

Tachycardia (disease definition)

An abnormally fast heart rate, generally defined as above 100 beats per minute in adults

Tachycardia causes

Stress, anxiety, fever, excessive caffeine or nicotine intake, heart conditions, electrolyte imbalances, or hormonal changes

Tachycardia symptoms

Palpitations, dizziness, lightheadedness, chest discomfort, shortness of breath, or fainting

First steps in CAD/MI treatment

Smoking cessation and treatment of high blood pressure

Smoking's effect on cardiovascular risk

Accelerates the development of atherosclerosis and increases cardiovascular disease risk by damaging the arterial lining, leading to plaque buildup, narrowed blood vessels, and elevated blood pressure

Lifestyle ways to lower CAD/MI risk

Lowering dietary cholesterol, weight loss, stress reduction, and increased physical activity

Exercise's effect on cardiovascular function

Increases the heart's strength and efficiency, improves cardiac output, strengthens the heart muscle, promotes blood vessel dilation, and decreases the heart's workload, reducing the likelihood of cardiac events like MI

Aspirin (CAD/MI treatment)

Reduces coagulation, lowering the risk of thrombosis

Propranolol

A drug that blocks sympathetic stimulation and slows the heart rate

Nitroglycerin

Causes vasodilation to help reduce the afterload on the heart

Calcium ion channel blockers (CAD/MI treatment)

Block the movement of calcium into muscle tissue, reducing cardiac contractility

Balloon angioplasty

A procedure in which a surgeon threads a plastic tube into an arm or leg artery, guides it to the plaque-clogged segment of a coronary artery, then inflates a balloon on the tube's end to force the vessel open

Coronary artery bypass graft (CABG)

A surgical procedure in which a segment of another blood vessel from the patient's body is stitched from the aorta to a coronary artery past the point of obstruction

CABG naming convention

Named by the number of vessels repaired; as many as four coronary arteries can be rerouted, so a CABG may be called a single, double, triple, or quadruple coronary bypass