Like any organ in the body, the heart has its own blood supply that provides nourishment for it. The blood supply to the heart is provided by the coronary arteries, which carry oxygen and other vital nutrition that keep the heart functioning. With aging or with improper diet, fatty plaques can develop inside the lining of these arteries, which can result to its narrowing. This narrowing of the coronary arteries due to deposition of fatty plaques is called Coronary heart disease.
Coronary heart disease puts an individual at risk for a heart attack or a myocardial infarction. A heart attack is a life-threatening medical emergency that happens when part of the heart loses its blood supply for a long time. If the coronary artery is blocked because of a clot in combination with plaques that narrow down the lumen of the artery, the heart muscle loses its blood supply and dies. Consequently, the heart is not able to do its work of pumping blood to the rest of the body, leading to even more fatal complications.
Coronary heart disease is a very sneaky condition because it often presents with no symptoms at first. It remains silent for a very long time until the arterial occlusion or blockage becomes significant enough to cause a angina or disruption of heart cells. When a heart attack happens, an individual might experience the following symptoms:
- Severe pain or heaviness in the center of the chest that is not localized to a single point
- Pain or discomfort that radiates to other areas like the jaw, neck, left shoulder, left arm, back or epigastric area
- Difficulty of breathing
- Diaphoresis or cold sweats associated with feeling of doom
- Palpitations or the feeling of rapid or uneven heartbeats
- Nausea or vomiting
The recognition of any of these symptoms warrants activation of the Emergency Response Team or calling an ambulance. In general, the longer the heart is devoid of its blood supply, the more permanent the damages are and the lesser the chances for the heart to recover. Hence, it is crucial to recognize the symptoms of heart attack immediately so that actions can be taken to re-establish the blood supply as soon as possible.
In addition to a good history and physical examination, a physician might request for blood tests that detect chemicals in the blood that are indicative of a recent heart attack. In addition, an electrocardiogram (ECG) can also be done to record the pattern of contraction of the heart and detect any abnormalities. An echocardiography or 2D-echo is like an ultrasound for the heart, which checks for the activity of the heart muscles and visualizes its structure and contractility. A coronary angiogram (cardiac catheterization) , which is a more invasive test, is done to document any occlusion in the coronary arteries. This is done by accessing a peripheral vessel (like the one in the inguinal area) with a guidewire that traces its path to the heart. Once the wire is in the coronary vessels, a contrast material that lights up in X-rays is injected to show where the area of obstruction or narrowing is. The great thing about a coronary angiogram is that it is not only diagnostic but it can also be therapeutic. Under the same set-up, several interventions can be done to address the obstruction or the narrowing. The clot can be taken out immediately, or the narrowing can be dilated in the same setting.
Time is the most important element in the treatment of heart attack. The sooner the treatment is given, the better the chances of recovery. Treatments include:
- Oxygen—given via face mask to improve the oxygenation in the body
- Nitroglycerine—this helps to relax and widen the arteries so that more blood can flow through it
- Pain-killers (morphine)—decrease the severity of the chest pain
- Blood thinners—prevents formation of more clots
- Beta blockers—slows down the heart to decrease its requirement for oxygen
There are three possible ways of re-establishing blood supply to the heart:
- Clot busters. These medications are given intravenously to dissolve the clots in the coronary vessels.
- Angioplasty. This is done in the same manner as a coronary angiogram. Once the guidewire is in the defective coronary vessel, the clot can be taken out to relieve the obstruction. In case of a narrowed vessel, it can be dilated using a balloon; then a stent can be placed in it to keep it permanently open.
- Bypass surgery: If angioplasty is not possible or if there are too many occluded vessels, a heart bypass surgery is necessary. In a heart bypass surgery, the occluded portion of the vessels is bypassed by grafting a donor vessel (usually a vessel that is taken from the legs) and creating a new pathway for the blood supply of the heart.
After an episode of a heart attack, some of the symptoms might resolve completely while others might remain permanent. The heart might recover completely or it might remain permanently damaged. One thing is for sure: after an episode of a heart attack, a person will be given maintenance medications that have to be taken for life. Some of these medications include blood thinners (to prevent repeated clot formation in the future), lipid-lowering drugs (to prevent plaque formation in the lining of the vessels), and anti-hypertensive medications (to control blood pressure). Compliance to these maintenance medications is very important to prevent recurrence of a heart attack.
A heart attack can be prevented by controlling the factors that increase the likelihood of its occurrence. These risk factors are:
- Coronary Heart disease: Coronary heart disease is the greatest risk factor for heart attack. It can be controlled by lifestyle modification (diet and exercise) and by compliant intake of maintenance medications. ECGs, echocardiograms and cardiac catheterizations may also be used to diagnose coronary artery disease. Another test that is normally used is called a stress test. During this test, the patient is asked to run or walk on a treadmill while they are hooked up to an ECG machine. The heart rhythm is traced throughout the procedure and doctors can monitor whether there is enough blood supplying the heart during active movement. If a patient is unable to walk or run, the increased workload on the heart required for the test can be artificially simulated using medication.
- Hypercholesterolemia: High levels of cholesterol in the blood can lead to development of plaques and clots. This can be prevented by proper diet and medications.
- Hypertension: Compliance to antihypertensive medications and proper lifestyle changes can keep the blood pressure controlled and decrease the workload of the heart.
- Diabetes: Diabetes is linked to other metabolic diseases like hypercholesterolemia and hypertension. Diabetes can be controlled by proper diet and medications.
- Obesity: Obesity is linked to hypercholesterolemia, which predisposes an individual to develop plaques or clots. This is can be controlled by proper diet and exercise.
- Smoking: Smoking can cause a narrowing of the blood vessels, which increases the risk for heart attack. Quit smoking now, or do not smoke at all.
With the advancement of medical equipment to diagnose heart attacks more rapidly, new medications and less invasive surgical techniques, more and more patients recover from a heart attack nowadays. However, it is very important that a patient understands long-term recovery may require lifestyle adjustments such as healthy eating and stopping smoking. These may prove to be even more important than the actual medications they are discharged with.