2.8 Common Heart Diseases

Introduction

The heart is a vital organ that works continuously throughout life. However, it can be affected by various diseases that impair its function. These disorders of the heart and blood vessels are called cardiovascular disorders. They are the leading cause of untimely death in humans. This topic explains common heart diseases, including coronary heart disease, myocardial infarction, and angina.

Definition

Cardiovascular disorders are the disorders of the heart and blood vessels. They are the leading cause of untimely death in man.

The common heart diseases discussed here are:

• Coronary heart disease — includes arteriosclerosis, atherosclerosis, thrombosis, and embolism
• Myocardial infarction — heart attack; death of heart muscle due to lack of oxygen
• Angina — chest pain due to reduced blood flow to the heart

Main Idea

Cardiovascular disorders are the leading cause of untimely death in man. They include conditions that affect the heart and blood vessels, such as coronary heart disease, myocardial infarction, and angina.

Core Concept

Overview of Common Heart Diseases

Detailed Explanation

1. Coronary Heart Disease

What it is: Coronary heart disease refers to conditions that affect the coronary arteries (the arteries that supply blood to the heart muscle).

Key terms:

What happens in coronary heart disease:

• Arteriosclerosis: Hardening of the arteries.
• Atherosclerosis: Deposition of materials (cholesterol) in the arteries.
• Plaques: Deposits of cholesterol increase in size and begin to block arteries.
• Clot formation: Plaques can cause a clot to form on the irregular arterial wall.
• Thrombus: As long as the clot remains stationary, it is called a thrombus.
• Embolus: If the clot breaks away, it may block an artery at another location. The dislodged clot moving along with the blood is called an embolus.
• Haemorrhage: Hardened arteries lose their elasticity and may get ruptured, a process known as haemorrhage.

Simple explanation: Coronary heart disease is when the arteries supplying the heart become hard and narrow due to cholesterol deposits. This reduces blood flow to the heart muscle.

2. Myocardial Infarction

What it is: If the embolus or large plaque blocks a vessel in one of the coronary arteries of the heart, a portion of the heart muscle will not get a supply of oxygen. Due to lack of oxygen, this portion of heart muscle dies.

Key term:

• Infarction means death due to lack of oxygen.
• The whole process is called myocardial infarction (heart attack).

What happens:

• A coronary artery is blocked by an embolus or large plaque.
• A portion of the heart muscle does not get oxygen.
• The heart muscle cells die (infarction).
• This can lead to heart failure or death.

Simple explanation: A heart attack happens when a blood clot blocks a coronary artery. The heart muscle beyond the blockage is starved of oxygen and dies.

Treatment:

• Medical treatment: Use of an enzyme that dissolves blood clot.
• Coronary bypass surgery: Blood vessels from elsewhere in the patient's body are grafted to coronary arteries to improve blood supply to heart muscles.
• Angioplasty: Mechanical widening of a narrow or totally blocked coronary artery.

Prevention:

• Avoid food rich in salt and fats.
• Maintain healthy body weight.
• Control blood pressure.
• Do regular walk and exercise.
• Avoid smoking.
• Avoid stress.

3. Angina

What it is: Angina is chest pain or discomfort that happens when the heart is not receiving enough oxygen-rich blood.

What happens:

• The heart may beat faster and harder to gain more blood, causing a noticeable pain.
• Angina is not a disease. It is a symptom and a warning sign of heart disease.

Symptoms:

• Fatigue
• Nausea or vomiting
• Shortness of breath
• Sweating a lot

Simple explanation: Angina is chest pain that occurs when the heart muscle does not get enough oxygen. It is a warning sign that something is wrong with the heart's blood supply.

Intermediate Level

Common heart diseases include:

• Arteriosclerosis = hardening of arteries.
• Atherosclerosis = deposition of cholesterol plaques.
• Thrombus = stationary clot.
• Embolus = dislodged clot.
• Haemorrhage = rupture of hardened arteries.

• Blockage of coronary artery → heart muscle dies.
• Treatment: clot-dissolving enzymes, bypass surgery, angioplasty.
• Prevention: healthy diet, exercise, no smoking, stress management.

• Chest pain due to reduced blood flow to heart.
• Symptoms: fatigue, nausea, shortness of breath, sweating.
• Angina is a warning sign of heart disease.

Important Points

• - The disorders of the heart and blood vessels are called cardiovascular disorders.
• - Cardiovascular disorders are the leading cause of untimely death in man.
• - Arteriosclerosis is hardening of the arteries.
• - Atherosclerosis is the deposition of materials in the arteries.
• - The deposits of cholesterol are called plaques.
• - Plaques increase in size and begin to block arteries.
• - A stationary clot is called a thrombus.
• - A dislodged clot moving along with the blood is called an embolus.
• - Hardened arteries lose their elasticity and may get ruptured, a process known as haemorrhage.
• - If the embolus or large plaque blocks a vessel in one of the coronary arteries, a portion of the heart muscle dies. This is called myocardial infarction.
• - Infarction means death due to lack of oxygen.
• - Angina is chest pain or discomfort that happens when the heart is not receiving enough oxygen-rich blood.
• - Angina is not a disease. It is a symptom and a warning sign of heart disease.
• - The main symptoms of angina are fatigue, nausea or vomiting, shortness of breath, and sweating a lot.

Remember

• - Cardiovascular disorders = heart and blood vessel disorders
• - Arteriosclerosis = hardening of arteries
• - Atherosclerosis = cholesterol deposition
• - Plaques = cholesterol deposits
• - Thrombus = stationary clot
• - Embolus = dislodged clot
• - Haemorrhage = rupture of hardened arteries
• - Myocardial infarction = heart attack, death of heart muscle
• - Infarction = death due to lack of oxygen
• - Angina = chest pain, warning sign of heart disease
• - Treatment: clot-dissolving enzymes, bypass surgery, angioplasty
• - Prevention: healthy diet, exercise, no smoking, stress management

Common Mistakes

• 1. Confusing arteriosclerosis and atherosclerosis.
• - Arteriosclerosis = hardening of arteries.
• - Atherosclerosis = deposition of cholesterol plaques.
• 2. Mixing up thrombus and embolus.
• - Thrombus = stationary clot.
• - Embolus = dislodged clot that moves.
• 3. Thinking angina is a disease.
• - Angina is a symptom and a warning sign of heart disease, not a disease itself.
• 4. Confusing myocardial infarction with angina.
• - Myocardial infarction = heart muscle dies.
• - Angina = chest pain, but heart muscle does not die.
• 5. Forgetting the treatment options for myocardial infarction.
• - Medical treatment (clot-dissolving enzymes), bypass surgery, angioplasty.
• 6. Believing heart disease only affects older people.
• - Heart disease can affect younger people too, especially with risk factors like smoking, obesity, and diabetes.
• 7. Thinking heart disease cannot be prevented.
• - Heart disease can be prevented by healthy diet, exercise, no smoking, and stress management.

Quick Revision

60-Second Revision

• Cardiovascular disorders = heart and blood vessel disorders
• Arteriosclerosis = hardening of arteries
• Atherosclerosis = cholesterol deposition
• Plaques = cholesterol deposits
• Thrombus = stationary clot
• Embolus = dislodged clot
• Haemorrhage = rupture of hardened arteries
• Myocardial infarction = heart attack, death of heart muscle
• Infarction = death due to lack of oxygen
• Angina = chest pain, warning sign of heart disease
• Treatment = clot-dissolving enzymes, bypass surgery, angioplasty
• Prevention = healthy diet, exercise, no smoking, stress management
• Warning: Do not confuse angina (chest pain) with myocardial infarction (heart muscle death).