Prevention & Recovery
The ABCs of heart disease
Prevention & Recovery
The ABCs of heart disease
If you're worried about heart disease, you're wise. In Canada more women and men die of heart-related causes than of anything else. The good news is that you can do a lot to improve your odds for heart health, such as adopting good eating habits, exercising regularly, quitting smoking and staying up-to-date on the latest diagnostic techniques and treatments. The following is an A-to-Z primer on what's new and what you need to know to get – and stay – heart healthy.
ASA: Can taking an acetylsalicylic acid (ASA) tablet every day really keep the heart doctor at bay? Yes – but only for some people. ASA reduces the amount of hormonelike prostaglandins that can cause platelets to stick together and form blood clots. These clots can block coronary arteries, which causes heart attacks. An inexpensive and readily available therapy, ASA can be beneficial for people who have experienced angina (chest pain) or who have had a heart attack or a stroke caused by blocked arteries. For healthy people, however, ingesting regular doses of ASA to prevent a heart attack may not be a good idea. Taking ASA may prevent an initial heart attack but it may also cause bleeding or stomach irritation, so the dose and pattern of use are important. Check with your doctor before embarking on long-term ASA therapy.
Beta-blockers: This potentially lifesaving therapy blocks the action of the hormones epinephrine and norepinephrine, which are released when you are under stress. Beta-blockers slow the heartbeat, decrease blood pressure, normalize some irregular heartbeats and reduce contraction of the heart muscle. They're a recommended therapy for people who have suffered a heart attack, and although they still aren't prescribed as often as they should be, the number is on the rise. Patients who take this medicine tend to live longer than those who don't, and beta-blockers have also been proven beneficial in even the sickest patients who have congestive heart failure, a condition in which the heart is too weak to pump blood to the rest of the body.
Calcium Channel Blockers: Although there is much less controversy than a few years ago, this class of blood-pressure medication can't shake the controversy completely. Although CCBs are useful for lowering blood pressure, controlling symptoms and treating complications of heart attacks, such as arrhythmias, short-acting calcium channel blockers should be avoided as they may increase the risk of death in some patients. It was once found that CCB users have an increased risk of heart attacks and heart failure compared with those on other medications, but the Heart and Stroke Foundation says that is not the case with the CCBs currently being prescribed.
Defibrillators: These lifesaving devices deliver an electric shock to the heart to restore a normal heartbeat after cardiac arrest or to stabilize an irregular heartbeat. But speed is of the essence: studies show that survival rates after cardiac arrest decline by approximately seven to 10 per cent for each minute before defibrillation. Up to 45,000 Canadians die of sudden cardiac arrest each year. Ambulance workers and firefighters routinely carry defibrillators, but the Heart and Stroke Foundation declares that more should be put in public places, such as shopping malls, office buildings, casinos and sports arenas. Families or close friends of a patient who is at increased risk of sudden death can purchase their own defibrillator, but that decision should first be discussed with their physician.
Exercise: Most people know exercise is good for the heart; it can lower blood pressure and help control blood lipids, which are fats and oils that include triglycerides, phospholipids and cholesterol. Organizations dedicated to heart health recommend 30 minutes or more of moderate exercise most every day. However, research shows that short bursts of vigorous physical activity – as little as 10 minutes long – can also be beneficial if done several times a day.
Folic acid: Folic acid can cut your risk of heart disease. Studies have shown that it reduces the level of the amino acid homocysteine in the body – and high homocysteine levels have been linked to some heart diseases. In fact, high homocysteine levels are similar in terns of heart-related risk to smoking, elevated cholesterol and high blood pressure. Homocysteine metabolism is partly controlled by folic acid and other dietary B vitamins, including B6 and B12, so adopt a healthy diet to ensure adequate intake of B vitamins.
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Gene therapy: This heart therapy involves inserting altered genes into dead or unresponsive heart muscle to stimulate the growth of newer blood vessels. Canada entered the competitive gene-therapy research fray when the Heart & Stroke/Richard Lewar Centre of Excellence opened. This multimillion-dollar center focuses on developing novel gene-based approaches to diagnosing and treating two of the most important heart-related problems facing Canadians: hardening of the arteries and heart failure.
Hormone replacement therapy: Research once suggested that HRT significantly lowered the risk of heart disease in post-menopausal women. Unfortunately that is no longer the case. The Heart and Stroke Foundation now recommends that women with pre-existing heart disease avoid HRT and that young, healthy women not embark on HRT solely for the prevention of heart disease. Although HRT does help protect against osteoporosis and offers relief of menopausal symptoms, if you are approaching menopause and do not suffer from heart disease, the risks may still be greater than the benefits. Discuss your options with your doctor.
Inflammation: What makes some people with normal blood cholesterol levels drop dead of a heart attack? It might be due to low levels of inflammation attacking the heart. It has been proven that hardening of the arteries, or atherosclerosis, is an inflammatory disease like arthritis. In both cases the disease is the immune system's response to an injury. With arthritis the body attacks its own joints; with inflammatory heart disease its focus is the coronary arteries. In response to an injury in the wall of the artery, possibly caused by high blood cholesterol or smoking, the immune system mounts an inflammatory response that may lead to the rupture of plaque buildup in the artery. Doctors can now measure inflammation, using a simple blood test, to determine who is prone to a heart attack.
J-curve phenomenon: Blood cholesterol that is too high is linked to heart disease, but so is cholesterol that is too low. This phenomenon, when illustrated on a graph that plots the cholesterol levels in large groups of people against mortality from heart disease, often appears as a J-shaped curve. The curve shows that those with the higher levels of cholesterol closer to the top of the curve are more likely to die from heart disease. However, it also shows that those with the lowest cholesterol also have increased heart-related mortality. This phenomenon does not mean that lowering cholesterol is harmful. Normal cholesterol treatments do not cause the abnormally low levels associated with increased mortality. The same J-curve phenomenon can be seen with high blood pressure.
Kawasaki disease: This mysterious illness, characterized by fever, rash and swelling of hands and feet and other areas of the body, affects mostly young children. It's a leading cause of heart disease in these kids; in as many as 20 per cent of them, the heart is affected.
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Lipoprotein: There are several kinds of these particles in the blood. Research shows that people who have high levels of one of them – a lipoprotein called Lp(a) – have a 70 per cent greater risk of suffering a heart attack over a period of a decade than those with lower concentrations. The findings are based on a review of 27 studies involving more than 5,200 people who have survived a heart attack or had heart disease. Levels of Lp(a) are largely determined by genetics, and lowering levels with the B vitamin, niacin, can help prevent heart attacks.
Margarine: Cholesterol-lowering margarines can be found on grocery store shelves in the United States. These products contain either sterol esters from vegetable oils, soybean and corn, or stanol esters from wood pulp, which may help lower LDL levels by 10 to 14 per cent. These products don't replace cholesterol-lowering drugs and don't prevent the underlying cause of elevated LDL. Current Canadian legislation allows certain health claims on specific food products, but this margarine still isn't sold in Canada yet.
Nuts: Despite their reputation for being a forbidden food, nuts can actually be quite good for your heart. Nuts, including walnuts and peanuts, lower total cholesterol and LDL cholesterol without lowering the health-promoting HDL cholesterol. Eating nuts frequently can lower the risk of coronary heart disease by up to 50 per cent. Nuts are low in saturated fat and high in monounsaturated and polyunsaturated fats. They also contain plant protein, dietary fibre, plant sterols and phytochemicals, all of which may protect the heart, and they are a good natural source of vitamin E. But beware: many of the nuts on the supermarket shelves are salted and roasted in hydrogenated oils, both heart-unhealthy additives.
Obesity: Once thought to be only one of the contributing factors in heart disease, obesity is now considered a major risk factor. When body fat is centered on the abdomen, the risks are especially high. The World Health Organization defines obesity as having a body mass index (BMI) of 30 or higher, which translates into being about 30 pounds (66 kilograms) or more overweight. BMI, one method of determining body fat, is calculated by dividing weight in kilograms by height in metres squared. Researchers have discovered genes that contribute to obesity and have developed prescription weight-loss drugs.
Patches: This transdermal (through the skin) mode of drug delivery is proving to be a boon to heart patients and others wishing to avoid heart-related problems. Because drugs delivered by patches are absorbed through the skin, often there are few, if any, of the stomach-related side-effects that can accompany oral medications, although they can cause minor skin irritation. Patches are now thin, discreet and stick better than older products. For smoking cessation, nicotine patches are among the most useful aids. In angina treatment, patches deliver a predetermined amount of nitroglycerin to alleviate chest pain. Nitroglycerin increases the size of the coronary blood vessels to allow more blood to flow to the heart.
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Q-T wave syndrome: Long Q-T syndrome (LQTS) is a rare hereditity defect in the heart's electrical system, which usually occurs in otherwise healthy children or young adults. The term comes from the pattern of the heart's electrical signal as recorded on an electrocardiogram (ECG or EKG). People with this abnormal heart rhythm may suffer sporadic fainting spells or may show no symptoms. The condition can be fatal. So if an unusual fainting episode occurs in an otherwise healthy person, it should be checked out by a doctor.
Red wine: There is strong evidence that drinking alcoholic beverages has a positive impact on the heart. A 1999 analysis revealed that moderate drinking could translate into an almost 25 per cent reduction in risk of coronary heart disease. Among other things, alcohol may increase HDL cholesterol and inhibit the clumping together of platelets. The benefits of drinking alcohol apply to all types of alcohol – not just red wine. Some alcoholic beverages may contain compounds such as antioxidants that are especially good for the heart. But the Heart and Stroke Foundation of Canada does not recommend drinking alcohol for the sole purpose of reducing your risk of heart attack and stroke. If you already drink regularly, they advise that healthy adults imbibe no more than two drinks per day, with a weekly limit of nine for women and 14 for men. While a daily drink may be heart healthy, binge drinking raises blood pressure, which puts extra strain on your heart. Heavy alcohol consumption can also lead to liver disease.
Stents: More and more cardiologists are using these tiny mesh tubes to help keep arteries open after operations to remove the plaque that has narrowed them. According to the Cardiac Care Network of Ontario in Toronto, at least one stent is being implanted in 90 per cent of patients in that province who undergo an angioplasty. (Angioplasty involves inflating a balloon inside an artery to clear a blockage.) Patients who have a stent inserted into the artery at the same time as the angioplasty are less likely to need another angioplasty up to six months after treatment. And if that stent is coated with an anti-inflammatory drug that is released over several weeks to further inhibit the formation of plaque, the patient is even less likely to have a repeated procedure. But you must remember, stents are primarily used for managing symptoms, not for prolonging lives.
Tissue Plasminogen Activator (tPA): This clot-busting drug has been used for years to treat heart attack patients and is now being prescribed for certain stroke patients. In some patients treated with tPA soon after stroke symptoms appear, there is an immediate and dramatic reversal of symptoms, but only patients with an ischemic stroke – which is caused by blood clots in the arteries that supply the brain as opposed to a hemorrhagic stroke, which is caused by bleeding in the brain – can be treated with tPA. The drug breaks up the clots and restores blood flow to the brain. The problem is that it has to be administered within three hours of the onset of symptoms. The Heart and Stroke Foundation supports on-going research by the Stroke Network, which is organizing centers to administer tPA.
Unsaturated fats: These are the healthy fats, at least when compared with saturated fats found in animal products and palm and coconut oils. Unlike saturated fats, which raise blood cholesterol, unsaturated fats help lower cholesterol. According to nutrition experts, consuming no more than 10 per cent of your total calories from polyunsaturated fats can optimally reduce your risk of heart disease. A diet rich in monounsaturated fats also reduces your risk, but perhaps not as much. Sources of polyunsaturated fats include safflower, sesame, soy and sunflower seed oils; monounsaturated fats come from olive, canola and peanut oils. Both types are liquid at room temperature. Although these fats should be used in place of saturated fats, there are unclear links to other health problems such as gallstones and cancer.
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Vitamin E: Believing that vitamin E can help fight heart disease seems to make good sense. After all, it's an antioxidant and therefore supposed to promote good health. But a new Canadian-led study shows that vitamin E does nothing to prevent heart disease and, in fact, may be harmful to people who have existing heart problems such as blocked arteries, diabetes or other heart disease risk factors. The Heart and Stroke Foundation recommends that you get your vitamin E naturally – in fruit, vegetables and fish – but not in capsule form.
Waiting lists: You've heard about them; you may even have been on one of them. Waiting lists for cardiac surgery, such as bypass operations, are part and parcel of the Canadian health-care system. Having to wait for surgery is stressful and, in many cases, presents an economic burden to people who must take time off work. But now Canadians in seven provinces can use the Internet to track wait times for health services, including cardiac surgery. This allows patients to make more informed decisions about where they seek their health care. However, all sites stress that prior to making any changes to your medical treatment, you should discuss the decision with your physician or specialist.
X Syndrome: Chances are you know someone whose cholesterol levels are normal and who eats a low-fat diet but still suffered a heart attack. Many of these people may have Syndrome X, a metabolic disorder that is being talked about more and more in medical circles. People with this disorder can't move glucose into designated cells properly. Unlike people with type 2 diabetes, people with Syndrome X manufacture enough insulin to overcome insulin resistance so they avoid becoming diabetic. However, the very high levels of insulin that remain in their bloodstream promote damage to arteries, which can precipitate a heart attack.
Youth: Thanks to sedentary lifestyles, many heart-related risk factors such as plaque buildup in arteries already exist in adolescence. That's why it's important for families to instill heart-healthy habits when kids are young.
Zzzzz: People with certain sleep disorders are more likely to have high blood pressure, which puts them at greater risk for heart problems. One recent study published in The Journal of the American Medical Association also showed that sleep apnea, a serious interrupted breathing pattern sometimes characterized by snoring, could signal the presence of high blood pressure.
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