If the EKG (Electrocardiography) shows that there is an acute heart attack (myocardial infarction), then the goal is to open the blocked artery as soon as possible and restore blood supply to the heart muscle.
When a heart attack strikes, the key thing to remember is that time equals muscle. The longer the delay in seeking medical care, the more heart muscle will be damaged. There is a window of opportunity to restore blood supply to the heart muscle by unblocking the affected heart artery. Treatments must be done in a hospital and include administration of clot-busting drugs to dissolve the clot at the site of the ruptured plaque and heart catheterization and angioplasty (in which the blood vessel is opened by balloon, often with adjunctive placement of a stent), or both.
Emergency Medical Treatment
Hospitals have established treatment plans to minimize the time to diagnose and treat people with heart attack. National guidelines suggest that an electrocardiogram (EKG) be done within 10 minutes of the patient’s arrival in the ER.
Many things will occur at the same time as the EKG being completed. The doctor will take a history and complete a physical exam while the nurses start an intravenous line, place heart monitor lines on the chest, and administer oxygen.
Medications are used to try to restore blood supply to the heart muscle. If it wasn’t taken prior to arrival in the ER, aspirin will be used for its anti-platelet action. Nitroglycerin will be used to dilate blood vessels. Heparin or enoxaparin (Lovenox) will be used to thin the blood. Morphine can also be used for pain control.
There are two options (depending on the resources at the hospital) if the EKG shows an acute heart attack (myocardial infarction), and if there are no contraindications.
Heart catheterization
The favored treatment is heart catheterization. Tubes are threaded through the femoral artery in the groin or through the brachial artery in the elbow, into the coronary arteries, and the area of blockage is identified.
Angioplasty
Angioplasty (angio= artery + plasty=repair) is then considered if possible. A balloon is placed at the blockage site and as it opens, it squashes the plaque into the blood vessel wall. Afterwards, a stent or a mesh cage is placed across the angioplasty site to keep it from closing down. Guidelines recommend that the time from the time the patient presents to the hospital to having the blood vessel open be less than 90 minutes.
Not all hospitals have the capabilities of doing heart catheterizations 24 hours a day, and may transfer the patient with an acute heart attack to a hospital that has that technology available. If the transfer time will delay angioplasty treatment beyond the 90 minute window recommendation, clot-busting drugs may be considered to dissolve the blood clot that has obstructed the coronary artery. Tissue plasminogen activator (TPA or TNK) can be used intravenously. After TPA infusion, the patient may still be transferred for heart catheterization and further care.
If the EKG is normal but the history is suggestive of an heart attack or angina, the evaluation will continue with the blood tests described above. However, the patient will likely be treated as if the heart attack was happening with aspirin, oxygen, nitroglycerin and blood thinning medications until the presence of heart damage is proven not to be present. The treatment presumes heart disease until proven otherwise.
Heart Attack Complications
When a heart attack occurs, part of the heart muscle dies and is ultimately replaced with scar tissue. This leaves the heart weaker and less able to meet the needs of the body. This will lead to exercise intolerance including early fatigue or shortness of breath on exertion. The amount of disability is dependent on the amount of muscle pumping function lost.
Muscle that loses its blood supply becomes electrically irritable. This may cause a short circuit of the electrical conduction system of the heart. This may cause ventricular fibrillation, a situation where the ventricles do not beat in a coordinated function. Instead, they jiggle like a bowl of Jello and cannot pump blood to the body. Sudden death occurs. Patients are kept in the ER or admitted to the hospital while assessing chest pain to monitor their heart rhythm and hopefully prevent sudden death from acute heart attack or unstable angina which may result in ventricular fibrillation.
If this rhythm occurs while monitored in the hospital, it can be rapidly treated with no adverse sequelae.
