Heart Disease

Definition

This information item focuses upon heart disease resulting from atherosclerotic changes - the changes that occur because of the build up of plaques or fatty streaks on the interior walls of the blood vessels that supply oxygenated blood to the heart muscle. This is also known as coronary artery disease.

Description

The heart is a muscular pump in the chest. Throughout life it beats continuously and rhythmically to send blood to the lungs and the rest of the body.

The normal heart weighs approximately 10 1/2 ounces and is about the size of your fist. It beats 60 to 120 times a minute, depending on whether you are excited or resting.

The average blood cell makes a round trip through the body's arteries and veins every 60 seconds, and can hit speeds of up to 10 mph. The heart pumps your five quarts of blood around your body 500 times a day.

When the arteries become clogged with deposits made up of "bad" cholesterol, plaque, scar tissue, or calcium, the heart has a harder time circulating blood. This clogging causes a myriad of heart problems from angina pectoris (chest pain) to heart failure to a heart attack.

Causes and Risk Factors

The primary risk factors for the development of atherosclerotic heart disease are smoking, sedentary lifestyle, hypertension, diabetes, hypercholesterolemia, and a genetic predisposition to the disease.

Symptoms

In its early stages there are no symptoms. The first symptom is usually angina pectoris (chest pain) or heart attack.

Angina pectoris is discomfort or pain in the chest, typically, brought on by exertion and relieved by rest. The pain may be a dull ache in the middle of the chest or a feeling of pressure that may spread up to the neck or down the arms.

The major symptoms of a heart attack are intense chest pain, suddenly cold, sweating, weakness and nausea.

Diagnosis

The diagnosis of this problem is based upon clinical history and physical exam. Confirmatory tests include electrocardiography (electrodes are connected to the chest and heart activity is monitored) and measurement of the level of serum creatine kinase enzymes released into the blood by the damaged muscle. Another method is the heart imaging technique called an angiography (injection of dye into the arteries followed by x-ray).

Treatment

There are several treatment methods that will help improve blood flow through the arteries:

Medications

Beta blockers (propranolol, atenolol, nadolol, pindolol, labetolol). Beta blockers lower blood pressure by reducing the amount of blood pumped by the heart. These drugs may also reduce the risk of a subsequent heart attack in patients who have already had one. Possible side effects include fatigue, impotence, abnormalities in fatty substances in the blood and interference with blood-sugar regulation.

Calcium-channel blockers (nifedipine, nicardipine, verapamil, diltiazem). Calcium channel blockers relax blood-vessel walls, thereby lowering pressure. They are also quite expensive and may cause side effects such as constipation and swollen legs. There are also Nitrate-based drugs and vasodilator drugs.

Balloon Angioplasty

A nonsurgical procedure designed to dilate (widen or expand) narrowed coronary arteries. It works as follows:

First, a doctor inserts a thin plastic tube (a catheter) into an artery in your arm or leg. He or she then guides this catheter to the aorta (the large artery that conducts blood from the heart to the rest of the body). From there it passes into the coronary arteries.

As the doctor guides the catheter to the coronary arteries, the procedure is monitored by a special x-ray camera called a fluoroscope. Once the catheter is passed into the narrowed coronary artery, a second, smaller catheter with a balloon on its' tip is passed through the first catheter. You can think of this as one "pipe" passed through another.

As this second catheter is passed through the first, the balloon remains deflated; however, once the balloon tip reaches the narrowed part of the coronary artery, it's inflated. When the balloon is inflated, it compresses the plaque and enlarges the diameter of the opening within the blood vessel. After that, the balloon is deflated and the catheters are withdrawn.

The result of this procedure is that the blood vessel is dilated, and blood can flow more easily through the (formerly narrowed) part of the coronary artery.

In some situations a stent (small hollow tube) is placed to actually keep the artery open.

Bypass Graft Surgery

Bypass graft surgery was introduced as a way of treating coronary artery disease. In this operation (abbreviated as CABG and sometimes pronounced "cabbage"), cardiac surgeons remove part of the blood vessel (graft) from somewhere else in the body and attach it to a narrowed or blocked coronary artery so the muscle ordinarily supplied by the vessel can be nourished again. For many people who suffer from unremitting angina, CABG can provide dramatic relief.

The principle of bypass graft surgery is to construct a new channel so blood can get around the atherosclerotic blockages in the coronary arteries. Therefore, instead of trying to scrape out the plaques, the surgeon uses a segment of a vessel from another part of the body to transport blood to the far side of the obstruction. Usually the grafts are fashioned from one of the large, accessible saphenous veins that run down the inside of the leg, although recently there has been a trend towards using the internal mammary arteries located under the chest wall.

Electrophysiologic devices (Pacemakers)

The job of the pacemaker is to maintain a minimum safe heart rate by delivering to the pumping chambers appropriately timed electrical impulses that replace the heart's normal rhythmic pulses.

The device designed to perform this life-sustaining role consists of a power source about the size of a silver dollar (containing the battery) and, control circuits, and wires, or "leads, that connect the power source to the chambers of the heart.

The leads are placed in contact with the right atrium or the right ventricle, or both. They allow the pacemaker to sense and stimulate in various combinations, depending on where the pacing is required.

Prevention

You can do several things to prevent heart disease:

Begin or sustain some regular physical activity. Even a modest amount of activity each day will lower your LDL cholesterol and raise your HDL cholesterol. Exercise also improves your heart's pumping efficiency, benefits your circulation and increases your overall strength and endurance.

Increase your consumption of vegetables, fresh fruits, low-fat milk and other dairy products, grains, fish and poultry. The main objective here is to replace foods high in saturated fat with healthier foods. Multiple sources of information exist that will help you create a heart-healthy diet.

Know your cholesterol, LDL, HDL and triglyceride levels. The level of cholesterol in your blood is a good indicator of the health of your heart and blood vessels. Generally, the higher your cholesterol level, the greater your risk of heart disease.

• Ldl stands for low-density lipoprotein. LDLs carry cholesterol around the body. LDLs deposit cholesterol in blood vessels where they can eventually build up and restrict blood flow. The more LDLs you have, the higher your risk factor for heart disease.

• Hdl stands for high-density lipoprotein. HDLs remove cholesterol from artery walls and carry it to the liver, which breaks it down.

• Triglycerides are a type of fat present in foods and manufactured in the liver. The higher your triglyceride level, the greater your risk of heart disease.

Watch your weight. Obesity raises triglyceride levels, which in turn promotes heart disease. Diet and physical activity should help you lower and maintain your weight.

Know your family's history of heart conditions. A family history of obesity, diabetes, heart attack, stroke or high blood pressure increases your risk of heart disease so consult a cardiologist before the age of 55 for males and 65 for females.

Pay attention to the pain. If you feel your vitality generally slipping, have a checkup. If you are having chest pains go to the nearest emergency room.

Reduce your stress.

Don't smoke.

Limit the amount of alcohol you consume.

Questions to Ask Your Doctor

Are the symptoms I'm having related to heart disease?

Which test is the most reliable for diagnosing heart disease?

What type of treatment you will recommend?

What can I do to reverse the course of my heart disease?

Can you help me work through how to develop an improved program of physical activity? And the same for diet?

Am I a candidate for surgery?