All about coronary artery disease

DR. M. R. Bhuyian
To know about heart disease and to understand heart disease, we should know something about the heart. Heart is such an organ which goes on working from birth till death. Heart is made up of a special type of tissue and is sort of a pump, which supplies blood to the whole body. If heart remains totally blocked or inoperative for a couple of minutes then life comes to an end.
Two-thirds of the heart usually occupies the left, side of the chest whereas remaining one third occupies the right side of the chest. An average heart is about 12 centimeter long and eight centimeter wide. It weighs about 300 grams in case of male and about 250 grams in case of female. It has four chambers, two above and two below. The upper chambers are called atrium while the lower chambers are called ventricle. These atrium and ventricles-are again partitioned into right, and left, chambers. The It. chambers of the heart contains pure (Oxygenated) blood while the right, chambers impure (deoxygenated) blood. The main function of the heart is to receive impure (deoxygenated) blood from all over the body through the right, chambers and to send the same to the lungs for purification (oxygenation) and to distribute fresh (pure or oxygenated) blood to all the parts of the body through artery. Oxygen is very essential for all the cells. If there is lack of supply by the heart then the cells suffer from lack of oxygen. The life of cells depends on oxygen.
Like any other organs or parts of the body the heart requires oxygen for it's survival and activities. The heart gets its blood supplies and through the blood, the
vital oxygen, through coronary arteries.
If for some reason the coronary arteries fail partially or totally to supply adequate blood to the heart muscles, then heart itself suffers from oxygen deficiency and the condition is then called coronary artery disease (CAD) or 'ischemia. If ischemia continues for quite sometime (i.e.. coronary artery disease) it may precipitate or lead to sudden heart attack.
It may be thus said that ischemic heart disease arises due to impairment of blood supply inside the coronary arteries. This sort of impairment or block is usually caused by accumulation of fat inside the lumen of the artery. In layman's term it is block and in terms of medical science the impairment or the accumulation of fat causing impairment is called atheroma.
If total blockage of a coronary artery causes heart attack then the portion of the heart muscle supplied by the particular artery becomes necrosed or dead. In the term of medical science this is known as myocardial infarction.
As told earlier the heart derives oxygen from the blood supply of two main coronary arteries namely, the left and the right coronary arteries.
These arteries directly come out from the aorta. The left coronary artery divides into two major branches at the very beginning one of which is known as left anterior descending artery (LAD) and the other as left circumflex artery (LCX). Thus the three main sources supplying oxy¬gen to the heart are the RCA, LAD and LCX. If any one of these are occluded then the patient will feel chest pain with or without compression. Usually after the age of 40, there develops minor or negligible blocks in every person. However blockage amounting to 50 per cent or
more is taken to be disease and 70 per cent or more requires treatment. A blood clot (thrombus), if formed over or inside the block, the respective artery becomes 100 per cent blocked causing heart attack.
A block of 50 per cent or above in one artery is known as single vessel disease, two blocks and blocks in three arteries are likewise called double and triple vessel disease respectively.
Why heart attack occurs is not known. But prolonged observation and studies has identified some probable reasons or factors responsible for heart attac.
 These are commonly known as coronary risk factors.
These factors are again divided into three parts i.e. modifiable risk factor, unmodifiable risk factor and miscellaneous.
If we could control all these risk factors, we could prevent heart disease. Factors which could by controlled by human beings are known as (a) modifiable. They are:
1. Hypertension or high blood pressure.
2. Diabetes
3. Smoking
4. Hyperlipidimia or high cholesterol level. The factor which could not be controlled by man are (b) unmodifi¬able risk factors. They are:
1. Sex
2. Age
3. Family history-or family disease trait
(c) Miscellaneous:
1. Overweight or obesity
2. Lack of physical activity or exercise
3. Strain
4. Personality
Uncontrolled hypertension could give rise to ischemic heart disease. High blood pressure may cause numerous small cracks inside the artery and fat deposit may take place over these cracks. Besides this the thickness of the heart muscle increases due to high blood pressure resulting in greater oxygen requirement.
There tends to be high concentration of cholesterol or fat in the blood of diabetic patients, and their platelets could easily tend to clot.
Besides this the lumen of the coronary arteries of diabetic patients tends to narrow due to higher regeneration of cells of the walls of the arteries due to quantitative difference of insulin in blood in the diabetic patients. Risk of heart disease is much higher in the smokers group. Those who smoke half a packet of cigarettes are 2 times more prone to get heart disease then non smokers and a man smoking a whole packet a day is at three times more risk of getting heart disease than a non smoker.
There is nicotine in tobacco smoke.
This nicotine narrows the lumen of coronary vessels. Those who smoke, usu¬ally have higher Low Density Lipoprotien (i.e. LDL or bad cholesterol/and lower High Density Lipoprotein (i.e., HDL or good cholesterol.)
That's the reason the fat accumulates easily on the arterial walls. Moreover there is more fibrinogens in the blood of the smokers which makes the blood to clot quickly. The risk factors which could not be controlled humanly are sex, age and genetic factors.
The rate and trend of heart disease among male and female are not the same.
Women are relatively safe from heart disease upto the age group of 45-50 yrs. due to hormonal effects. Males below the age of 40 are 8 times more at risk of getting heart disease than women. But ratio of ischemic heart disease among men and women become almost equal at around the age of 65 yrs.

All about coronary artery disease

DR. M. R. Bhuyian To know about heart disease and to understand heart disease, we should know something about the heart. Heart is such an organ which goes on working from birth till death. Heart is made up of a special type of tissue and is sort of a pump, which supplies blood to the whole body. If heart remains totally blocked or inoperative for a couple of minutes then life comes to an end. Two-thirds of the heart usually occupies the left, side of the chest whereas remaining one third occupies the right side of the chest. An average heart is about 12 centimeter long and eight centimeter wide. It weighs about 300 grams in case of male and about 250 grams in case of female. It has four chambers, two above and two below. The upper chambers are called atrium while the lower chambers are called ventricle. These atrium and ventricles-are again partitioned into right, and left, chambers. The It. chambers of the heart contains pure (Oxygenated) blood while the right, chambers impure (deoxygenated) blood. The main function of the heart is to receive impure (deoxygenated) blood from all over the body through the right, chambers and to send the same to the lungs for purification (oxygenation) and to distribute fresh (pure or oxygenated) blood to all the parts of the body through artery. Oxygen is very essential for all the cells. If there is lack of supply by the heart then the cells suffer from lack of oxygen. The life of cells depends on oxygen. Like any other organs or parts of the body the heart requires oxygen for its survival and activities. The heart gets its blood supplies and through the blood, the vital oxygen, through coronary arteries. If for some reason the coronary arteries fail partially or totally to supply adequate blood to the heart muscles, then heart itself suffers from oxygen deficiency and the condition is then called coronary artery disease (CAD) or ischemia. If ischemia continues for quite sometime (i.e.. coronary artery disease) it may precipitate or lead to sudden heart attack. It may be thus said that ischemic heart disease arises due to impairment of blood supply inside the coronary arteries. This sort of impairment or block is usually caused by accumulation of fat inside the lumen of the artery. In laymans term it is block and in terms of medical science the impairment or the accumulation of fat causing impairment is called atheroma. If total blockage of a coronary artery causes heart attack then the portion of the heart muscle supplied by the particular artery becomes necrosed or dead. In the term of medical science this is known as myocardial infarction. As told earlier the heart derives oxygen from the blood supply of two main coronary arteries namely, the left and the right coronary arteries. These arteries directly come out from the aorta. The left coronary artery divides into two major branches at the very beginning one of which is known as left anterior descending artery (LAD) and the other as left circumflex artery (LCX). Thus the three main sources supplying oxygen to the heart are the RCA, LAD and LCX. If any one of these are occluded then the patient will feel chest pain with or without compression. Usually after the age of 40, there develops minor or negligible blocks in every person. However blockage amounting to 50 per cent or more is taken to be disease and 70 per cent or more requires treatment. A blood clot (thrombus), if formed over or inside the block, the respective artery becomes 100 per cent blocked causing heart attack. A block of 50 per cent or above in one artery is known as single vessel disease, two blocks and blocks in three arteries are likewise called double and triple vessel disease respectively. Why heart attack occurs is not known. But prolonged observation and studies has identified some probable reasons or factors responsible for heart attac. These are commonly known as coronary risk factors. These factors are again divided into three parts i.e. modifiable risk factor, unmodifiable risk factor and miscellaneous. If we could control all these risk factors, we could prevent heart disease. Factors which could by controlled by human beings are known as (a) modifiable. They are: 1. Hypertension or high blood pressure. 2. Diabetes 3. Smoking 4. Hyperlipidimia or high cholesterol level. The factor which could not be controlled by man are (b) unmodifiable risk factors. They are: 1. Sex 2. Age 3. Family history-or family disease trait (c) Miscellaneous: 1. Overweight or obesity 2. Lack of physical activity or exercise 3. Strain 4. Personality Uncontrolled hypertension could give rise to ischemic heart disease. High blood pressure may cause numerous small cracks inside the artery and fat deposit may take place over these cracks. Besides this the thickness of the heart muscle increases due to high blood pressure resulting in greater oxygen requirement. There tends to be high concentration of cholesterol or fat in the blood of diabetic patients, and their platelets could easily tend to clot. Besides this the lumen of the coronary arteries of diabetic patients tends to narrow due to higher regeneration of cells of the walls of the arteries due to quantitative difference of insulin in blood in the diabetic patients. Risk of heart disease is much higher in the smokers group. Those who smoke half a packet of cigarettes are 2 times more prone to get heart disease then non smokers and a man smoking a whole packet a day is at three times more risk of getting heart disease than a non smoker. There is nicotine in tobacco smoke. This nicotine narrows the lumen of coronary vessels. Those who smoke, usually have higher Low Density Lipoprotien (i.e. LDL or bad cholesterol/and lower High Density Lipoprotein (i.e., HDL or good cholesterol.) Thats the reason the fat accumulates easily on the arterial walls. Moreover there is more fibrinogens in the blood of the smokers which makes the blood to clot quickly. The risk factors which could not be controlled humanly are sex, age and genetic factors. The rate and trend of heart disease among male and female are not the same. Women are relatively safe from heart disease upto the age group of 45-50 yrs. due to hormonal effects. Males below the age of 40 are 8 times more at risk of getting heart disease than women. But ratio of ischemic heart disease among men and women become almost equal at around the age of 65 yrs.