Beginning a new section on cardiac care which is intended as a reference reading only and not as a medical manual or as a substitute for self treatment.
Please seek competent medical help if any medical problems arise.
This section covers the incidence, type of heart disease, risk factors and prevention with dietary guidelines which are helpful to you to make knowledgeable decision about your diet.
Key terms used for your understanding:
Angina or Ischemia: Chest pain due to insufficient flow of blood to the heart.
Arteriosclerosis: Loss of elasticity, hardening and thickening of the arterial walls.
Atherosclerosis: A form of arteriosclerosis characterized by narrowing of the arterial walls due to accumulation of fat and calcification.
Coronary heart disease (CHD) or Coronary artery disease (CAD) or Cardiovascular disease (CVD): Terms to describe the disease states that involve the network of blood vessels connected to the heart and their clinical manifestations.
Myocardial Infarction: Ischemia leading to tissue damage and necrosis. This condition can cause sudden death if medical attention is delayed.
Heart is a cone shaped hollow muscular organ and one of the most important organs of the body. The function of the heart is to maintain a constant and unmitigated supply of blood throughout the body. It is this organ that acts as a pump through a series of events known as the Cardiac Cycle. The heart is a muscular organ situated in the thoracic cavity between the lungs and is located in the lower portion on the left side below the chest. It is about the size of a fist and weighs a little less than a pound.
The heart is composed of three layers-
- Pericardium is the tough protective membrane and prevents friction between heart and other surrounding organs.
- Myocardium comprises of specialized muscle tissue called the cardiac muscle. This muscle is found exclusively in the heart.
- Endocardium forms a lining to the myocardium.
The heart has four chambers and four major valves. The right and left chambers are divided by a muscular wall called the Septum. The upper chambers are called the Atria and the lower chambers are called the Ventricles.
Network of blood vessels carry the blood from the heart through out the body. These are called the arteries and veins. The arteries transport oxygenated blood from the heart and the veins carry blood with carbon-dioxide into the heart. (Pulmonary arteries carry the un-oxygenated blood to the lungs and pulmonary veins carry the oxygenated blood from the lungs into the heart)
The two major coronary arteries are the left and the right coronary artery. The left coronary artery carries blood to the left side of the heart and the right coronary artery carries blood to the right side of the heart. The oxygenated blood from the lungs enters the left side of the heart and it is the job of the left ventricle to carry this oxygenated blood to all cells and parts of the body. Damage to this part of the heart can cause serious problem following a heart attack as it the left ventricle that is most dense with muscles.
Electrical changes in the heart.
The heart has an intrinsic pattern of regulating the heart beats. There are small groups of specialized neuromuscular cells in the myocardium that initiate and conduct impulses of contraction on the heart muscle. The Sino arterial node or the SA node is described as the ‘pace maker’ of the heart. It is this SA node that initiates impulses that stimulate the myocardium and causes the heart to beat rhythmically. The contraction and expansion process of the heart is known as the ‘heart beats’. The heart normally beats about 72 times a minute. With each beat the heart pumps approximately 70ml blood into the aorta. It is suggested that when not exerting too much your heart can beat 50 to 100 times a minute and circulates roughly about 5 liters of blood. When there is more exertion or stress it beats faster as the demand for oxygen and nutrients are more than normal. In people who lead an active life the rate of heart beat is slower than in people who lead a sedentary life. A pulse rate of 60 to 70 indicates normal functioning of the heart and a pulse rate of above 80 is an indication to consult your physician and modify your lifestyle. By taking the pulse of an individual it is possible to obtain and study the pattern of heart function. By taking the pulse of an individual it is possible to obtain more information like the rate at which the heart is beating, the rhythm or the regularity with which the heart beats occur and the strength or the volume of the beat.
Some factors that affect or increase the pulse rate are age, sex, exercise and emotional factors.
Cardiac out put.
Cardiac out put is the amount of blood ejected from the heart by each contraction of the ventricles or the amount ejected per minute. To maintain normal blood pressure a sufficient quantity ob blood must circulate through the vessels. Blood pressure is the pressure which the blood exerts on the walls of the blood vessels. The contraction of the left ventricle pushes blood into the aorta. The pressure produced at this time is termed as the systolic blood pressure. In an adult it is about 120mmHg. The pressure within the arteries when the heart is resting following the ejection of blood is the diastolic blood pressure. It is about 80mmHg in an adult. The blood pressure is expressed as BP =12O/80 mmHg.
Every organ and cell in the body requires and depends on a constant supply of nutrients as does the heart. It is the responsibility of the two coronary arteries to carry out this function of providing nutrients to the heart.
Cardiovascular disease (CVD) is one of the leading health problems in the western world. In India too, especially in the cities the incidence of heart disease is increasing at an alarming rate. Studies have shown that in our country 35 percent deaths occur due to CVD alone. Compared to cities the incidence of CVD in villages is lower. This is the result of urbanization and modern erratic life styles. With more information and knowledge about the factors causing such problems and by understanding the preventive measures it is possible to prevent heart diseases or ailments.
Coronary heart disease (CHD) also known as Coronary artery disease (CAD) is the most deadly form of cardiovascular disease. It is a slow and progressive condition and shows its symptoms much later. CHD is characterized by myocardial infarction (Ischemia) in the coronary arteries resulting in tissue damage or necrosis and sudden death. It is also characterized by disturbances in the heart rhythm or heart beat (ventricular fibrillation) and dizziness calling for immediate medical attention. Symptoms like suffocation, tightness or constriction and heaviness are usually experienced by people suffering from myocardial infarction. This condition is also called Angina. The pain can radiate to close by areas of the chest like the neck, arms and shoulders. Quick action can save many lives!
Heart Failure: When the pumping of blood by the heart is reduced considerably heart failure is the result. It often takes many years for this condition to develop. So, with a little consciousness and modification of your life style prevention is possible. Symptoms include edema in the limbs or extremities and pulmonary congestion or collection of fluid in the lungs.
Atherosclerosis: A major cause of CHD is atherosclerosis or hardening of the arteries where the walls of the blood vessels become thick and lose their elasticity. In atherosclerosis the blood vessels become narrow due to the accumulation of lipid cholesterol deposits and in arteriosclerosis there is a build up of calcium deposits. Both conditions have similar effect on the circulation. Atherosclerosis is the main cause of heart attacks and strokes and clot formation which obstructs the flow of blood and oxygen through the arteries. It is a slow progressive disease and manifests in the form of high blood pressure, heart attacks or angina and strokes. This condition also causes the arteries to become less permeable due to which ischemia or cell starvation occurs. It is important to understand that despite new and modern methods and technology in the diagnosis and treatment of CHD, the first sign or discomfort is a warning and should not be ignored. The first sign itself is life threatening as the condition is often asymptomatic in the initial stages. Most often people misunderstand the symptom and treat it for stomach problems or indigestion.
Myocardial Ischemia is characterized by disturbances in the heart rhythm or heart beat (ventricular fibrillation). Symptoms are dizziness and irregular heart beats and requires immediate medical attention. Other symptoms include heaviness, suffocation, tightness or constriction in the chest. This is also called ‘Angina’. This pain can radiate to close by areas of the chest like the neck, arms and shoulders. Medical attention should be given as soon as possible.
Heart failure: When the pumping of the blood by the heart is reduced considerably heart failure is the end result. Symptoms include pulmonary congestion and edema in the limbs. It takes a long time or some years before symptoms surface. So, even a lifestyle change can prevent it.
Cardiovascular diseases (CVD) are not just a disease of the aged or older people alone. The incidence of heart diseases is on the rise even in the age group of forties and fifties. The question often asked is whether heart diseases can be prevented and the answer is YES. It is important to study and understand the causes and the risk factors involved. A risk factor is often a habit or trait that increases the chances of developing a heart problem. Prevention of CVD involves identifying and management of the risk factors. Some of the common risk factors are listed below.
1. Blood fats or lipids (cholesterol, triglycerides and phospholipids).
Increased levels of serum cholesterol are the primary cause of heart disease as they lead to clogging of the arteries. Blood cholesterol level of 150mg /dl is considered desirable, 200 -220mg/dl is considered borderline and 240mg/dl is considered high. Cholesterol becomes a problem when an excess of low density lipoproteins or LDL is present in the blood. These are the primary transporters of cholesterol in the blood. This excess can trigger formation of plaques on the artery walls. High levels of other circulating fat in the blood like the triglycerides also increase the risk of cardio vascular diseases.
2. High level of blood sugar or diabetes.
Diabetes enhances the chances of heart attacks and is considered a major risk factor. In diabetes, the metabolic process of carbohydrates is upset and the level of sugar in the blood is elevated. Due to inadequate secretion of insulin the cells in the body are not able to utilize the sugar. Diabetes also affects the blood vessels and hastens the hardening of blood vessels. Both type 1 and type 2 diabetes can increase the risk of CVD.
Hypertension causes vascular injury and is a major risk factor for heart attacks, congestive heart failure and strokes. 120/80 is considered to be the normal level of blood pressure. When the blood pressure is high the heart is under tremendous strain to pump blood into the arteries. Hypertension can be caused by stress, cigarette smoking, obesity and high sodium intake.
Cigarette smoking is also one of the major causes of all fatal heart attacks. Chances of a heart attack are three times higher in smokers. Smoking directly influences thrombus and plaque formation. Both nicotine and its byproducts cause the heart to pump faster resulting in strain on the heart muscles (the carbon monoxide that is inhaled while smoking causes the formation of cholesterol deposits).
5. Sedentary life.
Studies and research have substantiated the fact incidence of heart attack is much less in people who exercise regularly and lead an active life. Exercise is essential to remove all energy blocks and will give a new lease of life to ones entire musculoskeletal structure. Sedentary lifestyle also increases the chances of developing obesity which is a causative factor in developing heart and its related problems.
Obesity is an excess of body fat. Obesity is defined as having a BMI (body mass index) greater than 30.A person who is 20 percent over the norm for their height, build and age is considered obese. Obesity has been linked to development of CVD and a host of other disorders like diabetes, hypertension, high cholesterol and triglyceride levels, kidney trouble and psychological problems.
7. Elevated levels of homocysteine in the blood.
Homocysteine is a sulphur containing amino acid. Elevated levels have been linked to CAD and strokes. High level of homocysteine damages the cell lining of the coronary arteries and interferes with the clotting mechanism. Deficiency of vitamin B12, folic acid, low levels of thyroid hormone, excessive smoking and kidney diseases have been linked to elevation of homocysteine in the blood.
Stress is considered a major factor that can accelerate ones heart rate and blood pressure resulting in progressive narrowing of the arteries. The heart stress nexus is characterized by increased heart rate, disturbances in the heart rhythm, increased blood pressure and an increase in blood clotting and blood thickness.
Other factors include age, sex, heredity or family history of cardiovascular diseases.
The key to maintaining a healthy heart is prevention or preventive measures that can curb the formation of blockages. Prevention is priority for two reasons: the incidence of cases in our country and in the west is rising and the incidences among the young are on the increase. It is recommended to get oneself medically examined on an annual basis after the age of 35 so that high risk individuals can be identified and treated.
Prevention should begin from a young age to avoid formation of fat deposits in children and teenagers. The principles of prevention are the same for all but varies in its degree of aggressiveness with regard to age and the type.
Primary prevention groups include infants, children and young adults who have no disease symptoms. This involves measures like healthy eating, healthy lifestyle habits, regular exercise and avoiding smoking.
Secondary prevention involves the treatment of cardiovascular heart disease that has manifested in the form of high blood pressure, anginal pain and breathlessness and hardening of the blood vessels. Special attention is given to people who have such symptoms as they are at very risk of subsequent myocardial infarction. A cardiology check up is recommended to identify early development of CVD or for early detection of blockages. Serious and rigorous diet therapy and lifestyle changes are required to slow down the development of lesions.
Tertiary preventive method aims at individuals who are already suffering from heart disease and are being treated for rehabilitation and reversal of condition. At this stage it is necessary to slow down ones pace of work (reduce work stress), stop smoking, control hypertension, weight, diabetes and reduce serum cholesterol levels. Emphasis should be on a diet with plenty of grains, legumes, fruits, vegetables, herbs, low fat dairy products and sprouts. All meat eaters should consciously avoid red meat, organ meat and should opt for poultry or fish. Lacto ovovegetarians can opt for egg whites. Individuals suffering from hypertension and heart diseases should keep a check on high use of salt.
Steps to “Eating for heart health”
Diet and exercise play an important role in the management of heart diseases and hypertension. The diet must consist of foods in amounts needed to maintain desirable body weight.
Following a balanced diet can help to reduce your risk of heart disease by lowering blood pressure, cholesterol and weight. Make sure your diet includes plenty of whole grains, sprouts, greens, vegetables, fruits, nuts and herbs.
- Opt for heart healthy fats like vegetable oils, olive oils, ground nut, rice bran, sunflower, sesame oils. Avoid butter, coconut, palm oils and processed foods with trans fats. Avoid fats in the form of salad dressings and spreads as these are high in saturated fatty acids. A teaspoon of flax seeds can be added into your daily diet. They are good sources of essential fatty acids.
- Have 3 to 4 helpings of fruits and vegetables in your daily diet. They are great sources of vitamins, minerals, phyto chemicals and fiber.
- Limit the use of processed or canned foods in view of the fact that these foods are not only rich in fat but also in sodium.
- Avoid all stimulating beverages like coffee, tea etc as they contain substances like caffeine and tannin. These substances stimulate nerves and muscles causing an increase in the pulse rate.
- Avoid alcohol. Like tea and coffee alcohol too is a stimulant that can affect the nerves and the liver.
- Tobacco or smoking has been reported in medical books to be a potential poison. Studies have shown that nicotine stimulates and increases the secretion of adrenalin and nor adrenalin in the blood. This can lead to hardening of the blood vessels, irregular heart beats, anginal pain and heart attacks.
- Exercise plays a pivotal role in prevention of cardio vascular diseases. Regular exercise benefits the heart by increasing its efficiency and tolerance. Select a routine or pattern that suits you so that continuity can be maintained. Calisthenics, pilates, treadmill, ball exercises, stretching, resistance training and yoga are recommended. Ensure that these are done under supervision. Yoga postures or asanas exercise every part of the body. It stretches, tones the entire skeletal system, muscles, joints and the spine. Yoga keeps all internal organs, nerves and the glands in radiant health. The pranayama or the yogic breathing helps to calm your mind and revitalize the body. Meditation is another powerful practice in bringing about calmness and balance.
- Eat more complex carbohydrates and avoid simple carbohydrates. Include whole grain cereals like whole wheat or multi grain breads and pasta, brown rice, oat and oat bran and millets.