ANATOMY OF THE HEART
“The heart is located midway between the two lungs, leaning a bit to the left of center,” explains Dr. Wattanapol. “The heart is comprised of an independent cardiac muscle that’s wrapped by a thin protective sac called the pericardium. The heart’s weight ranges from about 200 to 425 grams.”
Dr. Wattanapol continues: “In a single day, the average heart will contract 100,000 times as it pumps out blood to the lungs and throughout the human body. The heart works non-stop, 24 hours a day, without any breaks.”
The key components of the heart include:
- Pericardium: This is the thin lining that surrounds the heart.
- Coronary arteries: Located outside the pericardium, the two main coronary arteries supply blood to the cardiac muscle - one serves the left side of the heart, while the other serves the right side.
- Cardiac muscle: With each contraction, the cardiac muscle fulfills its purpose of pumping blood out into the body's circulatory system. Each contraction creates pressure that helps keep blood flowing. The cardiac muscle is critical to life; irregularities in contractions can ultimately reduce blood flow and lead to life-threatening problems.
- Endocardium and cardiac valve: The endocardium is the thin innermost layer of tissue that lines the heart's four chambers.
Another important element of the heart is its electrical system. “The heart muscle produces electricity when it contracts and expands,” Dr. Wattanapol explains. “That electrical energy flows to the heart’s four chambers, providing the energy needed to maintain the cardiac muscle’s rhythmic beating that keeps blood flowing throughout the body.”
The heart is the core of the body’s complex circulatory system. A vast number of health conditions and irregularities can impair its ability to function properly. The specific conditions that comprise heart disease can be categorized into types, depending on the cause of the condition.
Some types of heart disease are present at birth (congenital), while other types occur later in life. Heart disease symptoms
and severity can vary greatly from one person to another.
The leading types of heart disease:
- Congenital heart disease: This describes a group of conditions affecting the heart that occur during the development of the fetus, prior to birth (“in utero”). Possible causes of congenital heart problems include viral infections and exposure to chemicals or drugs during pregnancy; these can cause a baby to be born with a defect in the heart’s walls, valve stenosis and mitral regurgitation, among others.
- Rheumatic heart disease: Rheumatic heart disease can often be traced to a throat infection. In a typical case, as the patient’s immune system responds to fight the throat infection, the response triggers other infections in one or more organs and can cause inflammation and permanent damage to the heart valves.
- Heart muscle (hypertensive) disease: Having high blood pressure for a long period of time can lead to hypertensive disease. This disease results in serious damage to the cardiac muscle.
- Coronary artery disease (atherosclerosis): The gradual build-up of artery-clogging plaque is the most common cause of coronary artery disease. It is most often caused by accumulation of plaque in the blood vessels. Therefore, the blood vessels can not supply enough blood to the heart as usual.
- Pericardial heart disease: Inflammation of the pericardium - often the result of viral infection, bacterial infection, or tuberculosis - causes pericardial heart disease. Treatments for this type of heart disease are highly effective, except in cases where cancer has spread to the pericardium.
- Cardiac arrhythmia: This condition describes problems related to the heart’s electrical system, such as abnormalities in the electrical pathways. Risk factors include reduced blood supply to the heart, stress and anxiety, and consumption of alcohol, caffeine, and some drugs.
- Heart infection: Patients with a heart defect or abnormality are more susceptible to heart infections. When an infection causes an abscess, puss, or dental cavities, bacteria from the infected site can enter the body’s blood stream and eventually flow to the heart. Heart infections are typically found in patients with compromised immune systems. Intravenous drug use is also a risk factor.
- Heart cancer: This rare form of cancer usually results from the spread of cancer cells from adjacent organs such as the lungs or breasts.
CARING FOR YOUR HEART
While there’s little that can be done to prevent congenital heart problems, there are many ways to reduce the risk of developing most types of heart disease.
“The health of your heart is something that people can influence,” says Dr. Wattanapol. “An easy way to get started is through lifestyle changes. Eating right, exercising regularly, reducing stress, and quitting smoking are four of the most important steps you can take to protect against the key heart disease risk factors - high blood pressure, diabetes, and high cholesterol.”
What’s your heart disease risk? Take the quiz and find out.
- Are you a male over the age of 45 or a female over the age of 55? (Yes/No)
- Does a family member have heart disease? (Yes/No)
- Do you smoke? (Yes/No)
- Is your alcohol consumption excessive? (Yes/No)
- Are you obese? (Yes/No)
- Is your cholesterol level over 200? (Yes/No)
- Is your triglyceride level over 150? (Yes/No)
- Is your blood pressure higher than 140/90? (Yes/No)
- Do you frequently suffer from stress or anxiety? (Yes/No)
- Do you frequently eat junk food or high-fat foods? (Yes/No)
- Are you leading a sedentary, inactive lifestyle? (Yes/No)
If you answered “yes” to at least three questions, you may be at greater risk for heart disease. Your doctor can help assess your risk for developing heart disease and create a prevention plan to keep you “heart healthy.”
Source: Thailand Ministry of Public Health
Posted by Bumrungrad International
January 23, 2009