Knowledge Centre

Frequently Asked Questions

What are the major risk factors for heart disease?

The major risk factors for heart disease (also called cardiovascular disease or CVD) are smoking, high cholesterol levels, high blood pressure, physical inactivity, obesity, diabetes, age, gender, and heredity (including race).

What is high blood pressure and how is it treated?

Your heart pumps blood through a network of arteries, veins, and capillaries. The moving blood pushes against the arterial walls, and this force is measured as blood pressure.

High blood pressure results from the tightening of very small arteries (arterioles) that regulate the blood flow through your body. As these arterioles tighten (or constrict), your heart has to work harder to pump blood through the smaller space, and the pressure inside the vessels grows.

High blood pressure is so dangerous because it often has no symptoms. High blood pressure tends to run in families. Men are at higher risk than women, and blacks are at greater risk than whites.

In most cases, high blood pressure can be controlled by eating a low-fat low-salt diet; losing weight, if necessary; beginning a regular exercise program; learning to manage stress; quitting smoking; and drinking alcohol in moderation, if at all. Medicines, called antihypertensives, are available if these changes do not help control your blood pressure.

What is cholesterol and why is it so important?

Cholesterol is a fat-like substance (lipid) found in all body cells. Your liver makes all of the cholesterol your body needs to form cell membranes and make certain hormones. Extra cholesterol enters your body when you eat foods that come from animals (meats, eggs, and dairy products). Although we often blame the cholesterol found in foods that we eat for raising blood cholesterol, the main culprit is saturated fat, which is also found in our food.

Cholesterol travels to cells through the bloodstream in special carriers called lipoproteins. Two of the most important lipoproteins are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Doctors look at how LDL and HDL relate to each other and to total cholesterol.

LDL particles deliver cholesterol to your cells. LDL cholesterol is often called "bad cholesterol" because high levels are thought to lead to the development of heart disease. Too much LDL in the blood causes plaque to form on artery walls, which starts a disease process called atherosclerosis. When plaque builds up in the coronary arteries that supply blood to the heart, you are at greater risk for having a heart attack.

HDL particles carry cholesterol from your cells back to your liver, where it can be eliminated from your body. HDL is known as "good cholesterol" because high levels are thought to lower your risk for heart disease.

What are triglycerides?

Triglycerides are fats that provide energy for your muscles. Like cholesterol, they are delivered to your body's cells by lipoproteins in the blood. If you eat foods with a lot of saturated fat or carbohydrates, you will raise your triglyceride levels. Elevated levels are thought to lead to a greater risk for heart disease.

Although triglycerides serve as a source of energy for your body, very high levels can lead to diabetes, pancreatitis, and chronic kidney disease. As triglyceride levels rise, HDL levels fall, which may help explain why people with high triglycerides appear to have an increased risk for heart disease.

What is atherosclerosis?

Atherosclerosis is a condition where a waxy substance forms inside the arteries that supply blood to your heart. This substance, called plaque, is made of cholesterol, fatty compounds, calcium, and fibrin (a blood-clotting material). Scientists think atherosclerosis begins when the very inner lining of the artery (the endothelium) is damaged. High blood pressure, high levels of cholesterol, fat, and triglycerides in the blood, and smoking are believed to lead to the development of plaque.

Atherosclerosis may continue for years without causing symptoms until an artery becomes almost completely blocked.

What is coronary bypass surgery?

Bypass surgery improves the blood flow to the heart with a new route, or "bypass," around a section of clogged or diseased artery.

The surgery involves using a section of blood vessel from another part of the body to bypass a part of the diseased coronary artery. This graft creates a new route for blood to flow, so that the heart muscle will get the oxygen-rich blood it needs. The procedure may be a double, triple, or even quadruple bypass depending on the number of arteries affected.

Coronary bypass surgery has proved safe and effective for many patients who have the procedure. You can expect to stay in the hospital for about a week after surgery, including at least 1 to 3 days in the Intensive Care Unit (ICU). Your doctor will recommend a cardiac rehabilitation program to help you recover.

What treatment options are available to a patient with narrowed or blocked arteries?

A severely narrowed coronary artery may need treatment to reduce the risk of a heart attack. Coronary bypass surgery is one form of treatment, but there are other therapies that have been found effective among carefully selected patients.

  • Angioplasty, which opens narrowed arteries, is performed by interventional cardiologists. They use a small balloon-tipped catheter that they inflate at the blockage site to flatten the plaque against the artery wall. A thin wire is inserted into an artery in the leg and is guided to the site of narrowing in the coronary artery. The catheter is slipped over this guidewire and positioned at the blockage, where the balloon is inflated. After treatment, the wire, catheter, and balloon are removed. The hospital stay and recovery time for this procedure are shorter than that of bypass.
  • A stent procedure is often used in conjunction with balloon angioplasty. It involves implanting a mesh-like metal device into an artery at a site narrowed by plaque. The stent keeps the vessel open for proper blood flow.
  • Atherectomy may be an option for certain patients who cannot have balloon angioplasty. A high-speed drill on the tip of a catheter is used to shave plaque from artery walls.
  • Laser ablation uses a catheter that has a metal or fiber optic probe on the tip. The laser uses light to "burn" away plaque and open the vessel enough so that a balloon can further widen the opening.
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  • Percutaneous trans myocardial revascularization (PTMR) is performed by a cardiologist in the cardiac catheterization laboratory. Using a laser that has been feedthrough a catheter to the heart, the cardiologist creates tiny holes in the heart muscle. These holes become channels for blood to flow to oxygen-starved areas of the heart. Researchers believe that the procedure may cause new vessels to form, reducing the pain of angina. PTMR is used for patients who have not responded to other treatments such as medicines, angioplasty, or coronary artery bypass surgery.
What is a pacemaker and how does it work?

A pacemaker is a surgically implanted device that helps to regulate your heartbeat. Pacemakers use batteries to produce electrical impulses that make the heart pump. The impulses flow through tiny wires (called leads) that are attached to the heart. The impulses are timed to flow at regular intervals.

Most pacemakers work only when they are needed. These are called demand pacemakers. They have a sensing device that either shuts off the pacemaker if the heartbeat is above a certain rate or turns the pacemaker on when the heart is beating too slowly.

Pacemaker batteries can last up to five years or longer. Pacemakers and batteries can be replaced during a minor surgical procedure.

What is congestive heart failure?

Heart failure means your heart is not pumping as well as it should to deliver oxygen-rich blood to your body's cells.

Congestive heart failure (CHF) happens when the heart's weak pumping action causes a buildup of fluid (called congestion) in your lungs and other body tissues. CHF usually develops slowly. You may go for years without symptoms, and the symptoms tend to get worse with time. This slow onset and progression of CHF is caused by your heart's own efforts to deal with its gradual weakening. Your heart tries to make up for this weakening by enlarging and by forcing itself to pump faster to move more blood through your body.

Many therapies can help to ease the workload of your heart. Treatment options include lifestyle changes, medicines, trans catheter interventions, and surgery.

What does the term "enlarged heart" mean?

An enlarged heart means the heart is larger than normal because of heredity or disorders and diseases such as obesity, high blood pressure, and viral illnesses. Sometimes doctors do not know what makes the heart enlarge.

What is cardiac catheterization?

Cardiac catheterization is the method doctors use to perform many tests and procedures for diagnosing and for treating coronary artery disease. Cardiac catheterization is used for tests such as angiography and electrophysiology studies (EPS).

The method involves threading a long, thin tube (called a catheter) through an artery or vein in the leg or arm and into the heart. Depending on the type of test your doctor has ordered, different things may happen during cardiac catheterization. For example, a dye may be injected through the catheter to see the heart and its arteries (a test called angiography), or electrical impulses may be sent through the catheter to study irregular heartbeats (tests called electrophysiology studies).

What is carotid artery disease?

Carotid artery disease is a form of disease that affects the vessels leading to the head and brain (cerebrovascular disease). Like the heart, the brain's cells need a constant supply of oxygen-rich blood. This blood supply is delivered to the brain by the 2 large carotid arteries in the front of your neck. If these arteries become clogged or blocked, you can have a stroke.

Carotid artery disease is usually caused by atherosclerosis, which is a hardening and narrowing of the arteries. As we age, fat deposits, cholesterol, calcium, and other materials build up on the inner walls of the arteries. This build-up forms a wax-like substance called plaque. As the plaque builds up, the arteries become narrower, and the flow of blood through the arteries becomes slower.

Lifestyle changes, medicines, trans catheter interventions, or surgery can be used to treat carotid artery disease and lower your risk of a stroke.

What is a stroke and what are the warning signs of stroke?

A stroke is an injury to the brain that may also severely affect the body. A stroke happens when blood supply to part of the brain is cut off or when there is bleeding into or around the brain. This can happen if a blood clot blocks an artery in the brain or neck or if a weakened artery bursts in the brain.

Risk factors for stroke include high blood pressure, smoking, heart disease, diabetes, and a high red blood cell count. The risk of stroke also increases with age. Heavy alcohol use increases your risk of bleeding (hemorrhagic) strokes.

The warning signs for stroke may include a sudden, temporary weakness or numbness in your face or in your arm or leg; trouble talking or understanding others who are talking; temporary loss of eyesight, especially in one eye; double vision; unexplained headaches or a change in headache pattern; temporary dizziness or staggering when walking; or a transient ischemic attack (TIA).

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