Heart Disease
By Dr. Philip Ho Yew Choong
Hospital Pantai Putri
Heart disease affects almost all of us in some way or another. It would be unusual for anyone not to have a relative or friend who suffers from some form of heart disease. In fact, heart disease is the leading cause for hospital admissions as well as being one of the commonest cause of death. In this brief article, I shall try to give an overview of what types of heart diseases affect us as well as how we can diagnose and treat these illnesses.
Types of heart disease
There are many different types of heart diseases and as such, they may present with very different symptoms. Some examples are given below:
1.Ischaemic heart disease-narrowing of the coronary(heart) vessels
2.Heart failure-this may occur following a heart attack or in a
condition known as cardiomyopathy
3.Valvular heart disease-the valves are either leaking or hardened
4.Rhythm disturbances-the heart either beats too fast or too slow or
irregularly
5.Hole in the heart-this may be from birth or after a heart attack
This is a condition in which there are blockages in the coronary(heart) vessels. Almost everyone will have progressive narrowing of the coronary vessels as they grow older. These blockages are due to cholesterol deposition on the inner surface of the blood vessels. What is not fully understood, however, is why some people develop it when they are 90 years old whereas some others may develop it when they are as young as 30 years old.
From research surveys we have identified certain characteristics which put individuals at higher risk of developing heart disease. These characteristics are known as risk factors.
What are the risk factors for ischaemic heart disease?
While we are unable to predict with certainty who will develop heart disease in the future, we do know that certain characteristics will put an individual at higher risk of developing IHD.
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MODIFIABLE
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NON MODIFIABLE
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Smoking
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Age
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Hypertension
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Male sex
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Diabetes Mellitus
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Family history
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Sedentary lifestyle
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Race
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High Cholesterol
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Stressful environment
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The benefit of knowing the risk factors for heart disease is that we can reduce each personﾒs risk of developing heart disease by controlling the modifiable risk factors. Whilst it is obvious that we cannot prevent age from catching up, alter our sex or change our parental lineage, we can refrain from smoking, seek medical attention to assure optimum hypertensive and diabetic control, exercise regularly and eat healthy diets.
It is also a good practice for healthy individuals to go for regular medical check ups to assess oneﾒs risk factors and to take preventive measures before developing heart disease. After all, prevention is better than cure.
What does heart disease feel like?
Some of us have a higher threshold for pain whilst others have a lower threshold. It is not the intensity of pain which tells you that you have heart disease. In fact many individuals describe a dull gripping sensation rather than sharp pain when they have a heart attack.
The classical description of chest pain originating from IHD is a central dull ache, which occurs during strenuous activity. This is called angina. Most often, this occurs when doing unaccustomed exercise, lifting heavy objects or climbing up a slope. The ache is relieved by rest and subsides in 5-10 minutes depending on the severity of the blockages. The pain can also be felt in the left side or can radiate to the jaw or left arm. There may be transient shortness of breath as well.
These are warning signs that you have blockages in the arteries and you should seek early medical attention to determine the severity of the blockages.
If left unattended, the blockages gradually worsen up to a point when the blood flow is so slow that the blood clots in the artery. If this happens, then the individual will suffer a heart attack (myocardial infarct in medical terms).
Diagnosis of IHD
Several tests will be done such as a resting 12 lead ECG which will show signs of previous heart attacks(infarct),a chest X ray which will show the size of the heart and presence of any fluid in the lungs and certain blood tests to determine the blood sugar and cholesterol levels.
The main screening test for IHD is the stress test. During this test, you will be required to walk on a motorised treadmill machine which will run at standard preprogrammed speeds. It will gradually increase in speed every 3 minutes as you complete each stage. During this time you will have a continuous ECG tracing. The test ends when you reach your target heart rate or when you feel chest pain or are too tired to continue. The important point to remember is that it is not how far you can walk but whether your ECG changes with exertion. If there are ECG changes when you are exercising compared to resting, then you have a high probability of having heart disease. This is called a positive stress test.
CORONARY ANGIOGRAM
If you have a positive stress test, then you will be advised to undergo a coronary angiogram. The purpose of this test is to determine the severity of the blockages.
This test is done as an inpatient procedure and you will be required to stay in hospital for 2-3 days. It is done under local anaesthesia and you will be awake during the procedure. After the local anaesthetic is given, a needle will be inserted into your artery either from the leg or from the arm. A small tube called a catheter will be passed along the vessels until it reaches your coronary arteries(see diagram).Then contrast will be injected into your coronary arteries and pictures will be taken with a sophisticated angiogram machine. The pictures will enable your cardiologist to determine how many of the 3 main vessels have blockages and how severe the blockages are.
Since this is an invasive procedure, there is a risk of developing complications such as a stroke or heart attack during the procedure. However, the risk is less than 1%.
BALLOON ANGIOPLASTY
This procedure is also done under local anaesthesia in the catheterisation laboratory. The catheter is inserted and a balloon is inserted into the artery which is narrowed. The balloons come in various sizes and your cardiologist will choose one which fits the diameter of your natural blood vessel. When the balloon has been placed in the appropriate position, then balloon will be inflated for a duration of 30 seconds to 1 minute. This is repeated several times until satisfactory results are obtained.
Coronary stenting
Coronary artery bypass grafting (CABG)
Bypass surgery is recommended for patients who have extensive blockages or if the left main stem artery is narrowed. It is necessary to have a coronary angiogram performed first to determine how many and where the blockages are prior to surgery. Recovery period from an uncomplicated operation is usually 10 days in hospital with a further 1 month at home. The overall risk of bypass surgery is in the region of 5% but this varies depending on the patientﾒs age, general health and other factors such as the presence of diabetes or kidney failure.
HEART ATTACK (Myocardial infarct)
A heart attack occurs when the diseased vessel is suddenly occluded by a blood clot. This presents with chest pain like angina but is continuous and is not relieved by rest or GTN tablets. This is a medical emergency and the patient should seek urgent treatment in a hospital which has a coronary care unit (CCU).
An ECG will usually show typical changes of an infarct (heart attack) and this can be confirmed in the emergency department by a rapid troponin T test on a blood sample.
Once admitted to CCU, the patient will be monitored closely with a continuous ECG tracing, blood pressure and pulse rate. Intravenous drugs will be given to reduce the strain on the heart as well as to dilate the coronary blood vessels. Aspirin and heparin will be given to prevent further clots from forming.
If the patient arrives early enough, streptokinase or tPA can be given intravenously to break up the clots which have already formed to enable blood to flow again in the occluded vessel.
Once the patient has been stabilised, your cardiologist will discuss the option of performing a coronary angiogram to determine the extent of blockages. It is important to understand that streptokinase or tPA will only dissolve the clots and that the cholesterol plaques still need to be attended to.
In uncomplicated heart attacks, the patient will usually stay in CCU for 3 days and can be discharged after 1 week of hospital stay. Thereafter, recuperation at home for 1 month is recommended.
TREATMENT OF PATIENTS WITH IHD (ischaemic heart disease)
If you have been recently diagnosed to have IHD, the first thing to remember is that worrying will not improve your condition but can worsen it. There are many people walking around who are suffering from IHD and leading relatively normal lives.
Some lifestyle changes would obviously be necessary. Smoking will have to be stopped and if you are overweight, you will need to start on a diet programme to achieve your ideal weight. Obesity will put added strain on your heart.
Even if you are not overweight, you will need to eat a low cholesterol diet. This would mean avoidance of fatty foods, deep fried meat, crabs, prawns, oysters, red meat, egg yolks etc. Your cardiologist will be monitoring your cholesterol levels every 4-6 months. The target level if you have heart disease is 4.5mmol/L.
After you have had your coronary angiogram done and the extent of blockages are known, then your cardiologist will be able to advise you when to start on an exercise programme. This exercise programme should be gradual as you build up your stamina. Do not attempt to run 5 km on your first day! The types of exercises recommended for heart patients are brisk walking, cycling, swimming or jogging. You are not advised to go to the gym and start weight lifting! You should try to exercise for at least 30 minutes 3 times a week. It is important to bring along your GTN pills with you when you go out walking or jogging in case you get chest pains. Try to avoid secluded areas and preferably go with a healthy friend who can help you in case of an emergency. If you cannot find a partner to go with you, try to bring a cellular phone so that you can call for help in case of an emergency.
You will be prescribed several drugs to take on a regular basis. Follow the cardiologistﾒs instructions and inform him if you have any side effects instead of stopping the medications on your own. There may be alternative drugs that he can prescribe for you.
Make sure that you have your GTN in all the familiar placesﾅ.by your bedside, downstairs in the hall, in the car etc. You should put one tablet under your tongue if you experience chest pain. If the pain is not relieved, then come to the hospital for an urgent ECG. The GTN tablets need to be protected from sunlight and need to be changed after a few months to ensure that you have a fresh supply when you need it.
During your follow up visits, you will be examined and a stress test will be done at regular intervals. This is to detect any recurrences at an early stage. To derive maximum benefit from your visits you need to be frank and honest about your progress. Tell your cardiologist if the medications are suitable for you and whether you have been compliant with your diet and exercise programme.
Depending on the severity of the blockages, your cardiologist will then advise you on the most appropriate form of treatment. Those individuals who have early blockages can be managed with medication alone. These medications help to prevent heart attacks and weakening of the heart muscles. They will also help in relieving symptoms of angina as well as retard the progression of existing blockages. However, medications alone seldom reverse existing blockages.
If you have 1-2 vessels which are blocked, then your cardiologist will discuss the option of balloon angioplasty with you.
If you have multiple areas of blockages, then perhaps the best option would be to go for a coronary artery bypass operation.
These are simple guidelines but treatment needs to be tailored to meet the needs of each individual. There may be other factors such as age, general health, kidney failure, patient preference etc which may alter the cardiologistﾒs decision on which modality of treatment to choose.
Echocardiogram
This is a non invasive test using a specialised ultrasound machine. It will enable your cardiologist to determine the overall contactile strength of your heart as well as to determine whether your valves are functioning properly.
Balloon angioplasty has become more popular in recent years as the patients are able to go home 1-2 days later provided no complications occur. The patients also do not have large scars to heal and the risk is less than going for a bypass operation. However, in individuals who have multiple areas of stenosis (blockages), there is a chance of recurrence. Recurrence is related to the extent of the original disease as well as the control of other risk factors ie smoking, diabetes, hypertension, exercise, cholesterol etc. In patients who develop recurrence of blockages, repeat balloon angioplasty can be performed as often as necessary. This is unlike bypass surgery which is difficult to perform the second or third time. Balloon angioplasty can also be offered to some individuals who have had bypass surgery done previously but have now developed blockages of the grafts.
If your cardiologist is unable to obtain satistactory results with the balloon inflation alone, then he will implant a coronary stent. This is a metallic structure which is somewhat like a spring loaded onto the balloon. The stent with the balloon will then be inserted through the catheter and placed at the stenotic (blocked) vessel. This stent will be left in the vessel and all other equipment withdrawn.
After taking a careful history, your cardiologist will do a physical examination to look specifically at your pulse, blood pressure, heart size and whether you have any murmurs.
