- Coronary Heart Disease
- Peripheral Arterial Disease
Heart disease is the leading cause of death in the United States.
1. What Is Cardiovascular System and Its Function?
The cardiovascular system is made of the heart, blood vessels, and the blood and is responsible for the following functions:
- Transport and supply the body’s tissues and organs with oxygen (O2) and nutrients.
- Transport hormones from secreting glands to target glands, tissues, and organs.
- Stabilize body temperature
- Maintain homeostasis (optimal functioning of the body such as fluid balance and body temperature).
- Transport of carbon dioxide (CO2) and metabolic waste (waste products from the metabolism of cells).
The blood vessels transport oxygen from the lungs through the respiratory circulation and nutrients from the digestive system.
Carbon monoxide is collected from tissues and organs by the blood and transported by the vessels to the lung for respiratory elimination.
Metabolic waste is also collected by the blood from the tissues and organs and transported by the vessels for elimination by the kidneys (urine), skin (sweating), and bowels.
The movement of blood within the body is ensured by the heart that works like the blood pump.
1.1. What Is Heart and Its Function?
The heart is a muscular organ that pumps blood carrying oxygen and nutrients to the body while also pumping out blood carrying dioxide of carbon and metabolic waste to organs such as lungs (CO2), skin, kidneys, and bowels.
- What Is the Structure of the Heart?
The human heart is a muscle made of 3 layers of tissue: the endocardium (inner layer), myocardium (middle layer), and the epicardium (outer layer).
The right and left atria (plural of atrium) receive the blood from veins and the right and left ventricles to pump out the blood from the heart.
However, valves exist between the atria and ventricles and are known as atrioventricular valves.
The valve between the right atrium and the right ventricle is known as the tricuspid valve, while the one between the left atrium and the left ventricle is known as the mitral valve or cuspid valve.
The heart also contains valves that connect between the right ventricle and the pulmonary trunk known as the semilunar valve, and between the left ventricle and the aorta known as the aortic semilunar valve.
During the contraction of the ventricles, the tricuspid and mitral valves close to prevent the blood from flowing back into the atria, while the semilunar and aortic semilunar valves open to allow the blood to flow out through the aorta and the pulmonary trunk.
- What Is the Function of the Heart?
The heart works as a pump that allows the flow of blood from the right atrium to the right ventricle where it is pumped out into the pulmonary trunk (large blood artery) to the lungs.
At the same time, blood coming from the lungs flow into the left atrium then into the left ventricle where it is pumped out through the aorta (largest blood artery) to the systemic system (circulation carrying blood to organs and tissues in the body).
1.2. What Are Arteries?
Arteries are blood vessels that mainly carry oxygenated blood to organs and tissues of the body. The largest artery of the body is the aorta which carries blood from the left ventricle of the heart.
Arteries branch into smaller ones known as arterioles (smaller arteries) which further branch into capillaries involved in microcirculation.
1.3. What Are Veins?
Veins are blood vessels that mainly carry deoxygenated blood from organs and tissues of the heart. Examples of body veins include the cardiac veins.
Like Arteries veins also have venules (smaller veins), and capillaries.
2. Most Common Cardiovascular Diseases
2.1. Coronary Heart Disease (CHD)
Coronary Heart Disease, also known as coronary artery disease or ischemic heart disease, is associated with the reduction in blood supply to the heart muscle due to the thickening of the heart arteries.
The thickening of the heart arteries is due to atherosclerosis.
Atherosclerosis is a disease of elastic and large arteries caused by the formation of atheroma (plaque build-up). It is considered a chronic inflammatory as inflammation is involved in the process of atherosclerosis .
2.1.1. What Are the Symptoms of Coronary Heart Disease?
An acute coronary event may manifest with the following symptoms:
- Angina (feeling of chest pressure or tightness, burning)
- Shortness of breath
- Neck pain
2.1.2. What Are the Risk factors for Coronary Heart Disease?
They are many factors that can increase the risk of coronary heart disease:
- High blood pressure
- Lack of physical activity
- High levels of cholesterol in the blood
- Family history
A stroke is the interruption of blood supply to the brain causing the death of brain cells. The longer is the lack of blood supply the more damage is caused to the brain.
2.2.1. What Causes Stroke?
The causes are associated with any event that causes the interruption of blood supply to the brain. The main causes are the following:
- Ischemic stroke which is due to a blockage of an artery.
- Hemorrhagic stroke due to the bursting of an artery causing hemorrhagie.
A transient ischemic attack is when the interruption of the blood supply is temporary.
2.2.2. What Are the Symptoms of Stroke?
A stroke manifests with the following symptoms:
- Facial paralysis on one side
- Trouble speaking or understanding others
- Difficulty lifting arms due weakness and numbness
It is extremely important to call for an emergency to prevent further damage to the brain.
2.2.3. What Are the Risk Factors for Stroke?
The following conditions increase the risk of stroke:
- Hypertension (high blood pressure)
- High cholesterol level in the blood
- Irregular heartbeats
2.3. What Is Peripheral Arterial Disease?
Peripheral Arterial Disease (PAD) is characterized by the blocking or narrowing of the blood vessels that carry blood to the legs.
The narrowing or blockage of the blood vessels is associated with atherosclerosis.
2.3.1. What Are the Symptoms of Peripheral Arterial Disease?
Due to the lack of blood supply to the legs, the following symptoms may manifest:
- Aches or cramps when walking (claudication) can happen to the hip, thigh, buttock, or calf
- Hair loss in the legs
- Change in skin color of the affected leg
2.3.2. What Are the Risk factors for Peripheral Arterial Disease?
The following factors can increase the risk of peripheral arterial disease:
- Age (above 60 years)
- High cholesterol level in the blood
Heart disease is the leading cause of death and is associated with risk factors such as diabetes, unhealthy diet, overweight and obesity, excessive alcohol use, and lack of activity and exercise. Therefore, changes in lifestyles can significantly prevent the consequence of heart diseases.