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Dr. Kenneth Rosenfield, of Massachusetts General Hospital in Boston, explains why every second counts when it comes to saving your heart muscle during a heart attack.
The first phase of heart attack treatment will be emergency treatment designed to save your life and limit disabling damage to the heart muscle. After that, treatment will be focused on recovery and prevention of future heart attacks.
Heart attack patients today have a much greater chance of survival than in decades past. They also are far more likely to be able to return to the quality of life that is normal for them. Consider, for example, the high-profile heart attack case of President Eisenhower in the mid-1950s. After the president had a heart attack, he remained in the hospital for seven weeks, and his recovery was not officially announced until months later. Today, a patient who undergoes angioplasty and stenting to stop a heart attack will typically be home within a few days.
When you arrive at the hospital as a heart attack patient, the initial focus will be on diagnosing the heart attack and stabilizing your condition. Treatment will be determined by the location and position of blockages in your arteries leading to the heart and by the capabilities of the hospital. (Not all hospitals may be able to perform all procedures.)
Treatment to stop the heart attack and reopen the arteries will consist of a range of three options: clot busters, angioplasty and stenting, and cardiac bypass graft surgery. A patient may also require treatment for cardiac arrest caused by the heart attack.
Clot Buster Medications
These medications, also referred to as thrombolytics, are powerful drugs used to quickly break up blood clots that can cause a heart attack. Clot busters are administered in the hospital through the veins to break up existing blood clots to try to restore blood flow. However, if there is underlying blockage from plaque in the vessel, then this blockage from plaque will remain even after thrombolytics. The thrombolytics dissolve the red blood cells and platelets that have gathered on top of ruptured plaque and completely obstructed blood flow. By restoring some flow, even if there is still, for instance, a 90 percent blockage remaining, the heart attack will be halted. However, even after thrombolytics, cardiac catheterization may be indicated at some point to treat the underlying blockage from plaque.
Angioplasty and Stenting
Angioplasty is a procedure that can stop a heart attack that is in progress by restoring normal blood flow through a blocked artery. During angioplasty a very thin wire is threaded through a blood vessel to the site of a blockage and then beyond it. Over this wire, small catheters may be advanced to try to suck out some of the clot. Also, balloons may be advanced over the wire to the site of blockage and then expanded to push the material that is causing the blockage out of the way. The goal is to reopen the blood vessel to as close to a normal diameter as possible, allowing blood to flow freely. In most cases, a stent is used. During this procedure, a metal, mesh tube called a stent will also be placed over the wire. The stent is expanded into place to permanently prop the artery open. Without a stent, an artery that has had a blockage cleared through angioplasty may collapse, once again cutting off blood flow.
The quicker a patient receives angioplasty to restore blood flow to the heart, the better the chances for a good outcome. Research shows that when patients suffering major heart attacks undergo angioplasty within 90 minutes of their arrival at the hospital, they are much more likely to survive the event and avoid significant damage to their heart. This is called door-to-balloon time, because it measures the time from when the patient enters the hospital to when an angioplasty balloon is expanded to clear the blockage causing the heart attack.
Today in the United States, nearly all heart attack patients who require emergency angioplasty to open blocked arteries are treated within the recommended 90 minutes from hospital arrival, a dramatic improvement from only five years ago when less than half of patients suffering a heart attack could expect to be treated within the 90-minute door-to-balloon time.
Cardiac Bypass Graft Surgery
Bypass surgery is typically recommended if blockages are present that are not optimally treated with stents. The decision to recommend bypass surgery may be because the blockages are in critical locations in the arteries of the heart, if the blockages in the heart are multiple and diffuse, or if a lengthy portion of an artery leading to the heart is narrowed. During bypass surgery, a surgeon takes arteries or veins from other parts of the body, such as the chest and the legs, and sews them onto the diseased arteries in the heart, beyond the obstruction that is blocking the blood vessel. The new arteries and veins serve to detour blood flow around the blockage, keeping blood flowing to the heart muscle.
A defibrillator is a device used to shock the heart’s rhythm back to normal. The heartbeat is governed by a series of natural electrical impulses within the heart. Application of a strong electrical shock to the heart can essentially reset the heart’s rhythm.
When a patient is having a heart attack, the heart muscle is being starved of the oxygen it needs to function. This can trigger dangerous, abnormal heart rhythms and even stop the heartbeat completely, a condition known as cardiac arrest. While not part of the heart attack itself, this disruption of the heart rhythm is also a life-threatening medical emergency that requires treatment.
Not all defibrillators are used in hospital emergency situations. Some patients can be identified ahead of time as being in danger of experiencing life-threatening heart rhythms. This risk will be determined by an electrophysiologist, a cardiologist who specializes in the heart’s electrical system. These patients may receive an implantable cardioverter defibrillator (ICD) or biventricular (BiV) ICD, each of which are devices that are surgically placed in the chest and that have leads (insulated wires) into the heart. If the implanted device detects an abnormal heart rhythm, it can painlessly pace the heart at a fast rate (overdrive pacing). If pacing is not successful, it can deliver a shock to get the heart back to a normal rhythm. A BiV ICD may also be implanted in patients for whom the amount of blood leaving the heart during each contraction (the ejection fraction) is not high enough to sustain healthy functioning.