The Big Ticker: Heart Disease
Nov 6, 2013
Clench your fist—that’s about the size of your heart. Located in the center of your chest, the heart beats about one hundred thousand times a day, pumping five to six quarts of blood per minute.
Once the blood receives oxygen from the lungs, the heart sends the blood from the aorta through the arteries and into the capillaries, which are smaller, thinner blood vessels. Then, once the capillaries have brought oxygen and nutrients to every cell in the body, the blood is redeposited into the veins, and from there it goes back to the heart for the cycle to begin again.
So what we have here is a plumbing system essentially, a smart pump with different connecting parts that circulates blood throughout the body. The heart itself is made up of four chambers—the two up top are called the atria, the two on the bottom are called the ventricles—connected by a set of valves. And the whole system is set in motion, or beats, thanks to the electrical impulses sent out by a small bundle of specialized cells in the right atrium that act as the heart’s natural pacemaker, causing the muscles of this organ to contract and relax.
Any malfunction of this blood pump is known as heart disease, of which one of the most common types is coronary artery disease. It is the No. 1 killer of both men and women in the United States killing more nearly half a million Americans each year.
Coronary artery disease, also known as coronary heart disease, is a narrowing and obstruction of the coronary arteries, which are responsible for bringing oxygen and nutrients to the heart itself. As early as your teen years, fat deposits begin to develop in some of these arteries, and as time goes by, the fat deposits build up, ultimately creating an obstruction that begins to decrease the amount of blood to the heart and cause an inflammation as the artery tries to heal itself.
Over time the fat deposits in the arteries begin to harden, and you begin to get deposits of small platelets that compound the obstruction. All of this can lead not only to a significant narrowing of the arteries, but to blood clots that may either obstruct the artery or get dislodged and create further obstructions elsewhere in the plumbing system.
One of the consequences of this narrowing or total obstruction of the coronary artery is ischemia, which occurs when there is an insufficient supply of oxygenated blood for the heart muscle. Any activity—eating, excitement, or changes in temperature—can make the problem worse.
One of the most common symptoms of ischemia is angina, which is a discomfort, heaviness, pressure, numbness, or squeezing feeling in the chest. Sometimes it is mistaken for indigestion or heartburn. It is usually felt in the chest, but it can also migrate to the arms, especially the left shoulder. Other symptoms include shortness of breath, irregular heartbeats or palpitation, a very fast heartbeat, nausea, and sweating. If this ischemia is not corrected, if it lasts more than 30 minutes and does not get better, a heart attack may result.
In a heart attack, the heart muscle begins to fail, either through a very erratic electrical stimulation called an arrhythmia or by stopping altogether. It is important to recognize these symptoms because early intervention could save your life.
A doctor can tell you if you have coronary artery disease by discussing your symptoms, especially shortness of breath, taking your medical history, and looking at your risk factors, in particular, smoking, cholesterol, blood pressure, and sugar control. There are a host of diagnostic tests your doctor can do, such as an electrocardiogram (ECG or EKG); an exercise stress test; an ultrafast CAT scan, which looks for calcium deposits in your coronary artery; and cardiocatheterization, which can help determine the degree of obstruction of the artery.
If you are diagnosed with coronary artery disease, treatment is threefold. The first has to do with lifestyle changes, like quitting smoking, starting to exercise, and keeping to a low-fat, low-sodium, low-cholesterol diet.
The second aspect of treatment is medication, which may be needed to get your heart working more effectively. Other medication will be prescribed to reduce the cholesterol.
The third aspect of treatment has to do with procedures to help improve the blood flow through the coronaries. One possibility is a balloon angioplasty, in which a small balloon-tipped catheter is inserted into the coronary arteries and then inflated to open up the clogged artery. Another possibility is placing a small, metal stent inside the artery to keep it open and improve blood flow.
A heart bypass operation takes place when total replacement of the piece of the coronary that is obstructed becomes necessary.
Plumbing Vs. Electrical Problems
Other types of cardiac disease have nothing to do with obstruction of the coronaries but with the way the electrical system of the heart works. Sometimes the specialized cells that electrically stimulate the heart become dysfunctional, and you can develop an arrhythmia, where the heart beats either too slowly, too quickly, or out of sync. These conditions can be diagnosed with an electrocardiogram, and sometimes medications alone can help to regulate the rhythm.
Another common problem is heart failure. This occurs when the heart can no longer effectively pump all the blood that it receives. Heart failure affects about five million Americans, and it’s the leading cause of hospitalization of people older than 65. Many times, heart failure is due to prior damage caused by coronary artery disease, or by arrhythmias that have weakened the function of the heart. Ultimately, heart failure creates a backlog of pressure into the lungs, and people with heart failure tend to have difficulty breathing. Depending on the cause of the heart failure, different medications are available for treating it.
The valves of the heart are another source of heart problems. The valves can be damaged at birth or through infection. Abnormal or infected valves can interfere with normal blood flow and heart function and can lead to major cardiac disease. Surgery may be needed to replace the valves.
Sometimes the lining of the heart may be infected, a condition called pericarditis. If this membrane is inflamed, the heart may not beat properly. Valve abnormalities, arrhythmias, and heart failure all have a common symptom—shortness of breath or difficulty catching your breath. If you have this problem, see a cardiologist to get the correct diagnosis and treatment.
The heart is a remarkable organ. It is the core of life, and its beat is central to your survival. Keeping it in prime working order is of paramount concern.