Diagnosis
If coronary heart disease is suspected a thorough physical assessment will be undertaken. This will include an assessment of risk factors and current symptoms. Additional tests to assist with making an accurate diagnosis may also be undertaken. Tests may include:
Blood tests
These check the levels of such things as electrolytes, blood cells, clotting factors and hormones in the blood. Specific enzymes and proteins that can indicate problems with the heart will be tested for.
Electrocardiogram (ECG)
A resting ECG records the electrical activity of the heart when at rest. This may show changes that indicate the heart muscle is not receiving enough oxygen. Electrical activity of the heart will be recorded using electrodes placed on the arms, legs and chest.
Exercise ECG/ Exercise Tolerance Test (ETT)
This test is designed to assess the heart’s response to exercise and stress. It involves walking on an exercise treadmill or riding an exercise bike for up to 12 minutes at varying degrees of speed and incline. Continuous ECG and blood pressure recordings are taken and symptoms of coronary artery disease such as shortness of breath, and pain in the chest, jaw or arm will be noted. A doctor and an ECG technician will be present at all times. Results based on the ECG, blood pressure recordings and any symptoms experienced can indicate whether coronary heart disease is present.
Echocardiography
Echocardiography is the use of ultrasound waves to display the movements of the heart as it beats. The image produced allows doctors to measure precisely the dimensions of the heart, to view the structures of the heart (such as the heart valves), and to assess any damage to the heart muscle.
Stress Echocardiography
This test, also referred to as a “stress echo”, involves the administering of certain medications into the blood stream through a drip in the hand or arm while the echocardiogram is being performed. These medications stimulate the heart and mimic the effect of exercise. This test is often used for people who are unable to exercise for medical reasons.
Angiogram
An angiogram (also known as cardiac catheterisation) is a diagnostic test that involves inserting a small, flexible tube (catheter) into an artery in the wrist or groin. Heart function and efficiency can also be assessed during this test.
CT Angiography
This computerised x-ray technology uses multiple cross sectional x-ray images to create detailed three-dimensional pictures of the heart. A contrast dye is injected through a vein in the arm and x-rays are taken while the person is lying on a specialised x-ray table. This is a non-invasive test that takes approximately ten minutes to perform, with a total hospital stay of only one to two hours.
Nuclear Isotope Imaging
Nuclear isotope imaging involves the injection of a radioactive compound called a tracer into the bloodstream. Computer generated pictures of the tracer are then taken as it moves through the heart. From these images it is possible to assess how the heart is functioning and detect any narrowed or blocked blood vessels. Nuclear isotope imaging techniques include: multigated radionuclide angiography (MUGA) and single photon emission computed tomography (SPECT).
Treatment
Depending on test results, various treatment options will be considered. Treatment may include medication, coronary angioplasty (with or without coronary artery stenting), or coronary artery bypass surgery (sometimes abbreviated to CABG). Treatment is aimed at reducing or eliminating symptoms andreducing the risk of having a heart attack.
Medications
Classes of medications commonly used to treat coronary heart disease include:
- Beta Blockers - These medications slow the heart rate and reduce the blood pressure thus reducing the heart’s workload.
- Nitrates - These medications dilate (widen) the arteries making it easier for blood to be pumped through.
- Calcium Channel Blockers/Calcium Antagonists - These medications work by slowing the entry of calcium into the heart and blood vessel walls. This relaxes the arteries causing them to dilate. This lowers the blood pressure and reduces the heart’s workload.
- ACE Inhibitors - These medications prevent the constriction of peripheral blood vessels thereby reducing the pressure against which the heart must pump.
Aspirin will also be prescribed (unless there's a medical reason not to) as it helps to prevent the formation of blood clots.
Coronary Angioplasty and Stenting
Coronary angioplasty is a non-surgical technique used to widen narrowed coronary arteries. The procedure is similar to an angiogram and involves inserting a balloon-tipped catheter into a narrowed coronary artery. As with an angiogram the catheter will be inserted through an incision in the groin or wrist. The patient will be awake but sometimes mildly sedated for the duration of the procedure. The balloon is positioned at the site of the narrowing in the coronary artery. It is then inflated, compressing the plaque and slightly stretching the artery wall. This increases the diameter of the artery and therefore improves the flow of blood to the heart.
Coronary angioplasty and stenting has a high success rate but it is not an appropriate treatment for all people with coronary artery disease. If the narrowings in the coronary arteries are numerous and severe, surgery may need to be considered.
Coronary Artery Bypass Surgery (CABG)
Coronary artery bypass surgery involves using a blood vessel taken from elsewhere in the body to restore blood flow beyond the area of narrowed artery. This is done by grafting one end of the blood vessel to the blocked coronary artery below the blockage or narrowing and the other end to the aorta, thus “bypassing” the blockage. Chest wall arteries, arteries from the forearm, and veins from the legs can be used as graft vessels. The operation takes approximately three to four hours and the average length of stay in hospital is five to seven days. The breastbone is cut during the procedure and can take up to eight weeks to heal. Patients will be advised to limit activities during this time.
Prevention
There are a number of steps that can be taken to prevent or reduce the risk of developing coronary heart disease. These include:
- Eating a healthy, balanced diet
- Limiting alcohol
- Not smoking
- Undertaking regular physical exercise – 30 minutes most days of the week
- Maintaining a healthy body weight
- Maintaining healthy blood cholesterol levels
- Effectively treating medical conditions such as diabetes and high blood pressure
- Being aware of risk factors.