What is Coronary Artery Disease?
The blood vessels of the heart (coronary arteries) transport blood and oxygen to the heart muscle. When these vessels become narrow or blocked, this becomes coronary artery disease.
In most cases, this blockage is due to the buildup of fatty substances (cholesterol) in the walls of the blood vessels. This leads to the narrowing of the space within the blood vessel (lumen), or a total blockage in more serious situations.
What is a Heart Attack?
A heart attack is a type of coronary disease. It occurs when a narrow artery within the heart suddenly becomes totally blocked. This means that part of the heart muscle has its blood supply completely cut off (i.e. hypoxia) which causes the heart to lose its ability to contract (contractile function) and pump blood. This also leads to that portion of the heart dying and lead to irreversible damage. The only way to save the heart is to medically bring back blood flow to that section.
Content by Dr. P.K. Lee, Cardiologist
Men have a higher risk earlier in life, but the women’s risk increases after menopause until it is similar to that of men
- Family History
In the immediate family, presence of heart disease in men before 65 and women before 55 indicate an increase risk in other family members
- High Blood Pressure
- High Blood Cholesterol
- Having Diabetes
- Being overweight
- Lack of regular exercise
Understanding High Blood Pressure
“High blood pressure” or hypertension is one of the most commonly seen diseases in a family doctor’s office. In B.C. 1 in every 3 people who pass away die due to a disease related to hypertension and its related complications.
In the human body the heart functions as a pump. The heart pumps blood through blood vessels to supply all of the body with blood. In this process a certain blood pressure must be maintained for the blood to be circulated through the body properly. Blood pressure is the pressure exerted upon the walls of blood vessels when blood circulates. The unit for measuring blood pressure is “millimeters of mercury” (mmHg). The blood pressure measured will be different when the heart contracts and relaxes. When the heart contracts, blood pressure will increase (systolic); when the heart relaxes, blood pressure will decrease (diastolic).
Risk Factors/Factors that determine blood pressure:
Signs & Symptoms
High blood pressure usually does not display any signs or symptoms. Some patients may experience headache, dizziness, fatigue, nervousness, insomnia and nosebleed but most patients are only diagnosed when they have their routine checkup with their family doctor. Even the first test cannot fully explain the problem so 2-3 tests are required for an accurate diagnosis. Generally, the blood pressure between the right and left arms are the same. But in very rare cases some people will have different blood pressure in their arms. In such cases the arm with higher blood pressure should be taken as accurate.
The chart below provides you with the numerical values of blood pressure for your reference. If you are a diabetic patient you should subtract 5 from all of the numbers.
When you have your blood pressure checked, you should also check for blood sugar and cholesterol level, urinalysis, kidney function, lung x-ray and eyes.
|Category||Systolic (mm/hg)||Diastolic (mm/hg)|
|Ideal||< 120||< 80|
|60+ years old||< 130||< 85|
|Normal, slightly high||130-139||85-90|
|Severe hypertension||≥ 180||≥ 110|
- Regular exercise
- Healthy Diet
Common High Blood Pressure Medications:
Some people can rely on exercise, losing weight, changing their lifestyle, or changing their diet to control their blood pressure. Although these changes are an important aspect of treatment without medication those changes alone may not be sufficient. Your doctor will determine if you need to take medication.
High blood pressure is a lifelong disease. If patients are required to take medication, they should take their medication according to their doctor’s instructions in order to enjoy a long healthy life. By controlling their high blood pressure, they will also prevent: damage to the heart vessels; heart attacks; stroke; blood clots; kidney failure; and other complications.
Useful information about taking blood pressure medications:
- Medications should be taken at the same time daily to be effective
- If you tend to forget to take your medication(s), place the medication bottle(s) next to things you use daily, like breakfast plates
- Most medications require up to 6 weeks to be fully effective, so be patient
- Do not start a new medication before bedtime in case your blood pressure becomes too low over night
- Long-acting medications (such as CR, SR, CD, XL) should be taken whole on a daily basis; you should never cut the pills into smaller pieces
- Taking a variety of low dose combination drugs rather than a single high dose drug is more effective and has less side effects
- Many patients require 2 or 3 types of medications at the same time to effectively keep their blood pressure within the ideal range
- Do not hesitate to use a few different types of medications, the most important thing is to protect the blood vessels and prevent complications from developing
- Do not take / exchange other patients’ medications; everyone’s health and reactions to medications are different, so let your physician decide the best combination for you
Current medical treatment for high blood pressure can be categorized as:
Lowers sodium and water content in the body which lowers the volume of blood going through the heart and decreases blood pressure
- Function: diuretic, eliminate edema, lower blood pressure
- Appropriate for: congestive heart failure, edema
- Not appropriate for: gout, kidney failure
- Side effects: long term effects are on blood fat, blood sugar, uric acid, blood electrolyte imbalance, and especially loss of Potassium and Sodium which will require food consumption to replenish
- Examples: Thiazides (HCTZ); HCTZ/ Amiloride (Moduret); Idapamide (Lozide); Spironolactone (Aldactone); Loop diuretics (Furosemide)
- Function: lowers blood pressure, treats arrhythmia and angina, slows heart rate
- Appropriate for: post heart attack, teenager with fast heart rate
- Not appropriate for: people with slow heart rate, asthmatic patients, chronic obstructive pulmonary disease, and severe peripheral arterial disease
- Side effects: fatigue, slow heartbeat, dizziness
- Note: people at the age of 60+ should not take this medication alone; these medications should not be discontinued abruptly as they need to be tapered off gradually.
- Examples: Atenolol (Tenormin); Metoprolol (Lopressor SR); Bisoprolol (Monocor); Propranolol (Inderal); Acebutolol (Sectral); Pindolol (Visken); Nadolol (Corgard)
Calcium Channel Blockers
- Function: lowers blood pressure, treats angina and arrhythmias
- Appropriate for: angina, high blood pressure
- Not appropriate for: congestive heart failure
- Side effects: swelling in the feet, headache, flush
- Note: should always use the long acting (CD, SR, XL) version rather than the short acting CCB, only requires to be taken once a day. Some CCB will slow down the heart rate as well (eg. Diltiazem, Verapamil). Taking Beta Blocker at the same time may cause dizziness because of decreasing heart rate and lowering blood pressure too much.
- Examples: Nifedipine (Adalat XL); Amlodipine (Norvasc); Felodipine (Renedil, Plendil); Diltiazem (Cardiazem CD, Tiazac); Verapamil (Isoptin SR)
ACEI-Angiotensin Converting Enzyme Inhibitors
- Function: lowers blood pressure, protects the heart, blood vessels, and kidney.
- Appropriate for: diabetics, congestive heart failure patients, post myocardial infarction, enlarged left heart and proteinuria patients,
- Not appropriate for: Black people, Renal Artery Stenosis, Kidney function failure, women trying to get pregnant
- Side effects: severe coughing (especially in Asians)
- Examples: Ramipril (Altace); Perindopril (Coversyl); Captopril (Capoten); Enalapril (Vasotec); Fosinopril (Monopril); Lisinopril (Prinivil, Zestril); Quinapril (Accupril); Trandolapril (Mavik); Benazepril (Lotensin)
ARBs-Angiotensin II Receptor Blockers
- Function: this type of medication has similar function as ACE inhibitors, it can protect the heart, blood vessel, and kidneys without causing coughing or other adverse reactions. This is a newer drug than ACE inhibitors.
- Appropriate for: Patients that cannot take ACE inhibitor
- Examples: Valsartan (Diovan); Irbesartan (Avapro); Candesartan (Atacand); Losartan (Cozaar); Telmisartan (Micardis); Eprosartan (Teveten)
- Function: lowers blood pressure, treats enlarged prostate
- Appropriate for: older men with an enlarged prostate
- Side effects: Postural hypotension and fainting, especially during first dose syncope. Drug dose should be increased gradually. Be extra cautious and move slowly when getting out of bed. Avoid driving at the first 24 hours. This drug should not be taken alone for the first time.
- Examples: Prazosin (Minipress); Doxazosin (Cardura); Terazosin (Hytrin)
Direct Renin Inhibitor
This is one of the newest drugs for lowering blood pressure
- Function: prevents the body from releasing angiotensin II which cause blood vessel to contract. As a result, blood vessels will be relaxed, lowering blood pressure.
- Not appropriate for: Pregnant women and anyone that’s below the age of 18years old
- Examples: Aliskiren (Rasilez)
Blood pressure Medication Combinations
These are drugs that combine two separate drugs into one pill to make it more convenient to use.
ACEI-Angiotensin Converting Enzyme Inhibitors + Diuretic
Ramipril + HCTZ (Altace-HCT)
Perindopril + Indapamide (Coversyl-Plus)
Lisinopril + HCTZ (Zestoretic, Prinzide)
Quinapril + HCTZ (Accuretic)
Enalapril + HCTZ (Vaseretic)
ARBS + Diuretic
Candesartan + HCTZ (Atacand-plus)
Valsartan + HCTZ (Diovan HCT)
Losartan + HCTZ (Hyzaar)
Irbesartan + HCTZ (Avalide)
Telmisartan + HCTZ (Micardis Plus)
Beta blocker + Diuretic
Atenolol + HCTZ (Tenoretic)
Propranolol + HCTZ (Inderide)
With the current available blood pressure medication, blood pressure can be effectively controlled with the correct pairing of medication and lifestyle. For patients that have high blood pressure, you should always take your medication on time and you should provide your doctor with your blood pressures for their reference. Measure your blood pressure two to three times a week after resting for 10 mins.
For hypertensive patients, the following factors may affect the effectiveness of the blood pressure medications:
- Did not take medications regularly or forgot to take medications
- Medication dose is too low
- Combination of medications being taken is inappropriate
- Poor diet and excessive amount of salt in diet
- Being overweight
- Smoking or excessive drinking
- Sleep apnea
- Psychiatric patients with other medications that interact negatively with hypertension drugs, e.g. Anti-inflammatory: NSAID, Cox-2 inhibitor, steroid drugs, contraceptive, decongestant, etc.
- Other disease that affects blood pressure, e.g. kidney failure, kidney blood vessel disease, adrenal tumor, pheochromocytoma, etc.
Hypertension patients on long term medication for lowering blood pressure should always carry their list of medication in case of emergency. Most importantly they should keep in touch with their doctor and return for periodic checkups. With the joint effort of the patient and doctor, hypertensive patients’ can enjoy a healthy life with controlled blood pressure.
Content by Dr. Thomas Ho, Family Physician
Cholesterol is a type of fat in the blood, and can be classified into two types:
- Low density lipoprotein cholesterol, also known as “bad” cholesterol because it can accumulate in the blood vessels. This causes thickening and hardening of the arteries which results in impaired blood circulation and may cause a heart attack. See figure.
- High density lipoprotein cholesterol, also known as the “good” cholesterol because it can transport the “bad” cholesterol to the liver where it can be removed from the body.
There is also another type of fat in the blood called triglycerides (neutral fat). Although it is not a type of cholesterol, triglyceride levels can increase and cause harm to the body and hyperlipidemia due to overweight, heavy drinking, or consuming too many sweets.
High cholesterol levels are a very important factor that causes heart diseases. Cholesterol is produced by our liver and we also get it from eating animal food products that contains cholesterol (e.g. beef, pork, dairy, egg yolk, cheese, butter, offal, lobster, crab, and mussels, etc.). Lowering your “bad” cholesterol levels can help prevent coronary heart disease, heart disease, stroke, and other diseases.
How to control cholesterol?
- Knowing the types of fats: Choosing a low-fat diet can reduce “bad” cholesterol level. Try to avoid eating food with high cholesterol, e.g. fatty meat, chicken skin, duck skin, pork skin, offal, egg yolk, homo-milk, and cream.
- Maintain a standard body weight: Your doctor and dietician can guide you with the appropriate BMI and healthy lifestyle.
- Exercise routinely and in moderation
- Stop smoking
- Drink alcohol in appropriate amount, according to your doctor’s instructions
- Take prescription drug on a timely manner
How much fat and cholesterol does the body require?
In a healthy diet plan fat should account for 25-30% of the daily calorie intake; this is approximately 55-65 grams. A controlled low cholesterol level is less than 200mg of cholesterol.
Before starting any new exercise regime, make sure to check with your doctor.
Exercise helps prevent or control cardiovascular disease in many ways. It helps to control the impact of many of the risk factors of heart disease, such as: high cholesterol, high blood pressure, obesity, stress and diabetes. There is also strong evidence that frequent exercise strengthens the heart and prevents heart attacks.
How do you exercise the heart effectively? You must engage in sports with a lot of physical activity. This will significantly accelerate your heartbeat and strengthen the heart. Such activities are called “aerobics activities” . Examples include: cycling, swimming, brisk walking, stair climbing, running and jogging. Some activities that also have a lot of benefits but are not aerobic activities are working in the garden, walking leisurely, bowling and weightlifting. . Ideally, in order to stay healthy a person should exercise 5-7 times a week, with each time lasting 30–60 minutes.
Your heart rate is the number of times your heart beats each minute. The goal of aerobic exercising is to reach 50–75% of your “maximum heart rate” while you exercise. This is your target heartbeat range. To calculate your target range, first calculate your maximum heart rate. One quick way of calculating this is to subtract your age from 220. For example, a forty year old person calculates their maximum heart rate as: 220 – 40 = 180. Then to get your target heartbeat range divide the result by 2 to get the lower number and divide your maximum by 4 and multiply that by 3 to get the higher number. For example, a 40-year-old doing aerobic exercise would aim for between 90 -135 heartbeats per minute (180/2 = 90 and 180/4=45*3=135). When you initially start exercising, set you target at the lower end of the range, for example 60%. As you increase your fitness, you can set your target higher, for example 85%.
The best exercise is something you like and can stick with. Walking is one of the best exercises because it is simple, easy, safe and inexpensive. The amount of calories burned with brisk walking is similar to running, but the risk of injury is much less. Walking does not require special training or equipment. You just need a pair of good shoes. It is also an aerobic and weight-bearing exercise and so is beneficial for your heart while at the same time it helps prevents osteoporosis.
- Choose a sport that you enjoy.
- Exercise 30 minutes daily. If necessary split your exercise into 3 sessions of 10 minutes each.
- Gradually build up your routine to allow your body to adapt to the exercise.
- Before starting actual exercise do preparation exercise and stretch your limbs.
- Choose an exercise with an appropriate pace
- Gradually slow down towards the end of your exercise.
- After the exercise routine loosen up and stretch your limbs.
- If you do not exercise for a few days, don’t jump right into intense activity.
- If you find yourself bored, switch to another form of exercise.
- If you want to lose weight, it is important to have a balanced diet as well as regular exercise
Content by Dr. Anthony Fung, Cardiologist
Eat a heart healthy diet which includes watching your:
The following symptoms often appear in people with blocked heart (coronary) blood vessels:
- Chest pains: Feelings of tightness or pressure on the chest, which usually appears during physical activities or mentally stressful situations. Usually, the discomfort spreads from the chest to the left shoulder and arm and sometimes up to the jaw and throat. Initially, the discomfort appears during relatively demanding activities such as a brisk uphill walk or climbing stairs. A short rest or a decrease in speed can alleviate the discomfort. For some patients, nitroglycerin tablets under the tongue or oral nitroglycerin sprays relieves the discomfort. However, as the disease progresses, this symptom can occur even while doing light activities or while resting.
- Shortness of breath: Patients experience shortness of breath in mild or active physical activities. He/she has difficulties carrying out normal activities. This is due to the heart muscle’s decreased ability to contract. As the disease progresses, shortness of breath becomes more serious even during light activities or resting. Lying down at night can produce the same feeling. Patients can use more pillows to elevate their bodies for easier breathing. Severe shortness of breath or fainting can lead to heart attack.
- Edema: Ankle swelling is a sign of excess fluid collecting in the cavities or tissues of the body.
- Irregular heartbeats (Heart palpitations): The patient may experience irregular heartbeat due to instability in the “electric circuit” which is the system that triggers the heart to beat. Heartbeats can suddenly become rapid and irregular.
- Sudden death: Unfortunately, as many as one-third of patients are discovered with coronary heart disease after a heart attack or sudden death.
Content by Dr. P.K. Lee, Cardiologist
Coronary disease is best diagnosed by a person’s medical history and a medical check-up by their doctor. If a patient exhibits any of the symptoms listed and/or has several of the risk factors, the patient should go for a heart check-up. Currently there are several ways to help diagnose the presence of coronary disease.
Commonly used methods for heart check-ups are:
ECG measures the electrical activity of the heart to test how well your heart is functioning. Electrodes are placed on the skin of the chest and of the arms and legs. On the electrocardiogram, the pulse beats of the heart are shown as waves. Each time the heart beats, it produces the wave shown in the image.
ECG can be used to determine:
- Irregular or abnormal heartbeats (arrhythmia)
- Decrease in blood or oxygen supply to the heart
- Previous heart attacks
- Damage to heart tissues
Exercise Stress Test
If a patient has chest pains and the doctor suspects it is due to coronary disease, the doctor will usually suggest an exercise endurance test. Electrodes connected to an ECG machine will be attached to the patient while the patient walks on a treadmill. The treadmill is slightly tilted to simulate going up a hill and it gradually increases in speed during the test which requires the patient to walk faster.
As the body exerts more effort to walk and then run faster, the heart will require more blood and the heart beats faster. As the heart beats faster, the blood pressure will go up. If the blood supply to the heart is not enough for the faster speeds, the ECG will display irregularities.
Through the exercise stress test, the doctor can diagnose problems with the heart blood vessels being blocked and also more accurately determine what level of exercise is most suitable for the patient.
Myocardial Perfusion Scan (MIBI)
When the doctor wants to know more about the heart’s blood supply and suspects the narrowing of coronary arteries, a nuclear scan may be required. The patient will be injected with a small amount of radioactive material (called thallium or MIBI). The patient lies on a special bed with a camera above (gamma camera) which takes pictures of radioactive activity. If a portion of the heart does not receive normal blood supply it will show as a blank space in the scanned image.
The first set of images is taken while the patient is at rest. Then the patient does the exercise stress test. A second set of images is taken after the patient completes the exercise. If the patient cannot perform the exercise due to muscle of skeletal problems, the patient may be prescribed dipyridamole (Dipyridamole or Persantine) to simulate the effect of actual exercise.
An echocardiogram is a test that uses sound waves to record the heart’s motion This test allows the doctor to check the functioning of the heart and its valves. When the patient has abnormal heart murmurs, has previously had a heart attack, or is suspected of having valve issues, an echocardiogram is required.
Computer Tomography (CT Scan)
CT scans use x-ray and sophisticated computer technology to obtain “the most conclusive” image. During the scan, the patient lies down on a narrow table and the body is pushed into the machine. Usually, a pigmented substance is injected into the veins of the patient to enable the doctor to see the vascular network of the heart. Some patients may have a sensitivity to this pigment and the scan can be done without it in this case. If you belong to this group, inform your doctor when he schedules the scan.
CT scans allows the doctor to clearly see the heart’s arteries, intravascular fat deposits, and any damage or death in the heart tissues.
Magnetic Resonance Imaging (MRI)MRI machine
MRI uses magnetic fields and radio waves of different frequencies to take high quality images of the heart. It does not use x-ray. MRI is very useful for people with congenital heart problems or for determining the extent of heart damage in people who have had heart attacks.
Coronary Angiography (Cath)
Coronary angiography enables the doctor to observe the heart and its blood vessels. Although other tests (such as MIBI or CT scan) can assist the doctor in diagnosing blockage in coronary arteries, coronary angiography is the most effective method. It is done in the hospital. The doctor usually threads a small tube from the patient’s femoral artery or wrist artery into the coronary arteries. X-ray dye is injected into the coronary arteries and flows into the smaller arteries of the heart. The path of the dye and any interruptions is recorded.
If the heart has severe blockages, a balloon angioplasty or a stent placement can be done. If a heart bypass surgery is required, it can also be done after this procedure.
Content by Dr. Anthony Fung, Cardiologist
- Quit smoking: Not only does this reduce the chance of you getting heart disease or if you already have heart disease then having it get worse, it also reduces the risk of stroke and lung cancer.
- Control high blood pressure: The usual goal is to keep blood pressure below 140/90 mmHg. In certain cases (for patients with diabetes, kidney failure or heart failure) the doctor will set an even lower goal.
- Control cholesterol levels: For people with coronary disease and diabetes, doctors will have stricter guidelines than for the general public. Borderline levels of cholesterol are definitely not good enough. Patients must ask their doctors for an acceptable cholesterol level for them since it is dependent on their coronary situation. To get a patient’s cholesterol level to where it should be usually requires both a controlled diet and medication.
- Control diabetes: Maintaining a healthy glucose level decreases the risk of diabetic complications, including the risk of cardiovascular disease complications.
- Control body weight: Patients should maintain a reasonable weight based on their gender and height. The waistline is also an important guide for preventing vascular diseases. A reasonable waistline for Asian men is less than 35 cm and for Asian women is less than 31 cm.
Exercise regularly: Exercise at least four times a week for 30 minutes each time.
Medication for Coronary Disease
- Nitroglycerin mouth sprays and nitroglycerin tablets placed under the tongue can be used for quick relief of chest pains. Those who frequently experience chest pains should always carry either the spray or tablets. If these do not help the chest pain the patient should go to the Emergency room.
- Oral nitroglycerin tablets or skin patches are used to prevent the return of chest pains (note: skin patches should stay on for 12 hours)
Blood thinners (Anti-platelet drugs)
- These drugs help prevent blood clots from forming in the blood and blocking the blood vessels. This reduces the risk of heart attacks.
- Aspirin is the most common drug of this type. If the patient has adverse reactions to aspirin, Clopidogrel (Plavix) may be used instead. In more severe cases Warfarin can be used.
- After a procedure such as balloon angioplasty or stent placements the patient is usually prescribed aspirin and Clopidogrel (Plavix). The medication is required from anywhere between a month to a year depending on the type of balloon or stent inserted. Failure to continue with medication can increase the risk of sudden blood vessel blockages and heart attacks.
- Helpful in the treatment of chest pains
- Helps prevent another heart attack
- Used to treat heart failure (weakened hearts)
- Used to treat irregular heart beats
ACEI-Angiotensin Converting Enzyme Inhibitors
- Used to treat heart failure (shows good results when taken with B-blockers)
- Used to treat high blood pressure
- Used to treat kidney failure especially when related to diabetes
- One side effect observed among Chinese people is a dry cough. In this case another group of drugs unlikely to cause a cough can be substituted (ARBs: Angiotensin Receptor Blockers)
Content by Dr. P.K. Lee, Cardiologist