HEART HEALTH
The heart is a blood-filled bag of muscle, about the size of a fist, located in the centre of the chest, deep to the breast bone. The muscle contracts about 70 times a minute, to pump blood around the body. In 24 hours, the heart beats approximately 1, 00,000 times and 7500 litres of blood pass through the heart in one day.
Like any other active tissue, the heart muscle needs a good blood supply of oxygen. It gets this from the blood stream. Its supply is taken, not from the blood which is being pumped through the heart, but from separate little arteries, the coronary arteries. The nutrients for the heart muscle are carried to it by two blood vessels – the left coronary artery (LCA) and right coronary artery (RCA).
ANGIOGRAM OF A HEALTHY HEART:
These two arteries are named coronaries, because they appear to provide crow for the heart. These arteries branch off from the main artery, the aorta and then divide into smaller branches which fan out all over the surface of the heart.
Coronary Heart Disease (CHD)
There are many different types of heart disease. The most common and tragic type that causes heart attack is called Coronary Heart Disease (CHD).
What goes wrong?
The coronary arteries are unique. They need to supply the heart and are so designed they pursue a wavy course instead of a straight line, so that they can adapt themselves to the beating of the heart. When the heart relaxes to receive blood and bulges, the blood vessels on its surface straighten out. When the heart squeezes and pumps the blood out, it becomes smaller. The blood vessels assume a wavy outline. The inner lining of the blood vessels is very smooth.
Over a period of many years, starting in early adult life, the walls of these arteries become ‘furred up’ with a fatty deposit called atheroma. If the atheroma gets too thick and the arteries too narrow, the blood supply to the heart muscle can become restricted or even blocked. This is coronary heart disease. Coronary heart disease indicates that the heart muscle does not receive the necessary oxygen for its functioning.
Coronary heart disease is a worldwide disease. It remains the major cause of morbidity and mortality in all developed world and in
CHD has 2 main forms: angina and heart attack.
What is angina? In simple words, angina may be called a cry on the part of the heart muscle devoid of adequate blood supply, consequently, cutting down its oxygen supply and threatening its life. Thus it is the question of supply and demand. If the narrowing of the coronary arteries is very gradual, then the first signs of trouble may
only be noticed when the heart is having to work harder than usual. Because the blood flow through the arteries is restricted, anything which makes the heart pump a little faster than usual- even if one walks, climbs steps, runs (equal to climbing two flights of stairs)- starves the heart of blood.
This brings on a heavy cramp-like pain across the chest, like a huge weight. Sometimes the pain spreads to the neck, shoulder, arm or jaw. It usually fades away after a few minutes rest.
This kind of pain is known as angina. It is not the same as heart attack because it is usually relieved by a short period of rest or relaxation. Any angina episode lasting for more than half an hour,, not subsiding with rest and specific drugs, associated with excessive sweating, dizziness, nausea and vomiting should be taken as acute heart attack and should immediately be reported to a doctor or any emergency room in a hospital, Somebody who suffers from angina does have a higher than average risk of having a heart attack. But angina itself can be relieved or controlled by drugs and in severe cases by surgery.
What is a heart attack?
A heart attack happens when there is a sudden and sever blockage in one of the coronary arteries, so that the blood supply to part of the heart muscle is cut off. The blockage is usually caused by a blood clot forming in an artery already damaged by the fatty atheroma. This is called coronary thrombosis.
The part of the heart muscle affected is severely damaged causing the pain that is the most common symptom of a heart
attack. The pain is usually, but not always a crushing vice-like ache felt in the chest. It can spread to the neck, jaw or arm. It does not usually ease off for several hours. As well as being in pain, the person usually sweats, feels faint, giddy, sick or vomiting. Sometimes the chest pain may not be severe, but other symptoms may be dominant.
In some cases, the effects of the blockage can be so severe that the heart stops beating altogether. This is called a cardiac arrest. Unless the heart starts beating within a few minutes, the person will die. About 50% of all fatal heart attack cases die within half an hour, often before medical help arrives. Some of the people could be saved by prompt emergency first - aid.
What causes Coronary Heart Disease?
What it is in our everyday lives that increase the risk of heart attack and angina? The results of the researchers show that there is no single cause of CHD. Instead there seems to be several different factors, which together may tip the balance against the heart. These are referred to as ‘risk factors’. eg: raised serum cholesterol, cigarette
smoking, elevated blood pressure, physical inactivity, obesity, diet, diabetes mellitus, continuing stress conditions, alcohol intake, heavy coffee drinking (more than 9 cups per day), etc.
Of course some people are more likely to suffer from CHD than others. For example, the tendency to die young from CHD can run in family. And certainly the incidence of CHD increases with age. The narrowing of the arteries which can lead to angina or heart attack tends to get worse with advancing age. In general, men are most at risk from heart disease than women. A man in his late forties is five times more likely to suffer CHD than a woman of the same age. But after menopause, a woman loses the protective effect of her hormones and her chances of suffering from heart disease are almost equal to a man’s. The risk of CHD in women appears to be 2 or 3 times greater than when oral contraceptive pills are used.
Cholesterol and CHD
Fat in the blood and tissues are called lipids and consist of cholesterol (HDL cholesterol and LDL cholesterol) and triglycerides.
Cholesterol is one of the natural substances in the blood. It is a type of fat which is essential to normal health. It is present in the membranes of every cell in the body and it is also used as the starting point for making some hormones.
Cholesterol is mostly made from the fat in the food we eat – animal fat, oils, milk, yolk of the egg, liver and kidneys, shell fish (prawns and lobster), fatty red meat. If there is a lot of fat in our diet, we may have a high level of cholesterol in our blood, a thick greasy sludge may form, which starts to block the blood vessel. The blood vessels of the heart are particularly vulnerable to becoming blocked and the result can be CHD. Egg white, fish, chicken, peas, beans, skimmed milk, skimmed milk cheese, salads, and polyunsaturated oils are safe from the point of view of cholesterol.
The cholesterol in our body is in many forms, (High density lipoprotein) HDL cholesterol is the ‘friendly’ cholesterol. It constitutes about 20-25% of the total
| cholesterol in the blood. It is generally regarded as ‘protective’ cholesterol. There is an inverse relationship between CHD and the HDL concentration. (Low density lipoprotein)LDL cholesterol is the ‘bad’ cholesterol. It is the carrier of about 70% of the total cholesterol. For a healthy heart, it is desirable to have a blood LDL to HDL ratio of 2:1, Total Cholesterol | |
| < 200 mg/dl | Desirable blood cholesterol |
| 200-239 mg/dl | Borderline-high blood cholesterol |
| > 240 mg/dl | High blood cholesterol |
| LDL Cholesterol | |
| < 130 mg/dl | Desirable LDL cholesterol |
| 130-159 mg/dl | Borderline-high risk LDL |
| > 160 mg/dl | High risk LDL cholesterol |
| HDL cholesterol | |
| Males > 50 mg/dl | Favourable |
| 40-50 mg/dl | Standard risk level |
| < 40 mg/dl | Risk indicator |
| Females > 60 mg/dl | Favourable |
| 45-60 mg/dl | Standard risk indicator |
| < 45 mg/dl | Risk indicator |
| Triglycerides | |
| Ratio of total cholesterol HDL cholesterol | < 4.5 |
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