Heart Attack Treatment Plans

The treatment of a heart attack varies somewhat from case to case. The first rule, however, is to get the person to a hospital as soon as possible. Almost one-third of people who have a heart attack die before reaching the hospital. Of those who do get to a hospital, the vast majority will recover.

Complete cardiac arrest (meaning that the heart stops beating) can occur at any time during a heart attack. Even if cardiac arrest occurs, the patient has a good chance of survival if cardiopulmonary resuscitation (CPR) is started within four minutes of the arrest. CPR is a simple technique using mouth-to-mouth ventilation and chest compressions to pump oxygenated blood to the brain even though the victim's heart is not beating. Although CPR is a simple technique to learn, it cannot be learned from a book. CPR courses are taught by local chapters of the American Heart Association and American Red Cross. If everyone were trained in CPR, an estimated 100,000 lives would be saved each year in the United States alone.

Once a person having a heart attack reaches a hospital, medical care will proceed through several phases. In the immediate phase, emergency treatment to reduce the severity of the attack is begun. Diagnostic tests are performed to confirm that a heart attack is occurring, how severe it is, and what part of the heart is involved. If the patient is hemodynamically unstablethat is, blood pressure is not sufficient to provide blood to all the body's organssteps will be taken to improve the function of the heart. If there are major heart rhythm disturbances, medication will be started to treat them.
Once the patient is stabilized, the care focuses on monitoring the patient for potential complications. Complications are most likely to occur within the first few days following a heart attack. If no complications occur, or when any complications have been treated and resolved, the patient begins a phase of rehabilitation along with treatment to prevent future heart attacks.

Immediate Treatment of Heart Attack, Emergency Care

Once a heart attack has occurred, the myocytes try to protect themselves from ischemia. Whenever they are starved for oxygen, myocytes stop contracting, conserving the last of their energy. They can exist like this for up to three hours, after which time they have sustained irreversible damage and will begin to die. This three-hour period is the "window of opportunity" during which some medical treatments can actually reverse the heart attack. After this time, at least a small area of the heart muscle will have died.

The first steps taken in the emergency room are to confirm that a heart attack is occurring and, at the same time, to begin treatment. Initial treatment includes supportive measures such as administering oxygen and giving morphine for the chest pain. Morphine also dilates the blood vessels, thus reducing the workload on the heart. Nitroglycerine, another medicine to dilate blood vessels, may also be administered. In many cases, one of the beta blocker drugs is given. These drugs slow the heart's rate and decrease the force of its contraction, lowering the heart's oxygen requirements.
For the majority of patients, the initial supportive care is continued while the medical team determines how severe the heart attack is. An EKG is performed and continuous monitoring of the patient's heart rhythm is started. The final diagnosis often is made by analyzing blood to determine if it contains certain enzymes that are normally found only in heart muscle. If these are present in the blood, some heart muscle cells have died. It may take three to twelve hours for cardiac enzymes to be detected, however.

In some cases, nuclear medicine scans with thallium or technetium can also be performed to detect heart attacks. Echocardiography (ultrasound of the heart) may also be used to assess the heart's pumping action. In a few cases, emergency angiography may be performed to find the site of coronary disease, and even to treat it.
During the first hours after a heart attack (and for several days thereafter), dysrhythmias are quite likely to occur and are a common cause of death. One of the most important parts of the initial treatment, therefore, is careful monitoring to detect any dysrhythmia. As a general rule, this involves admission for several days to a coronary care unit that has continuous EKG monitoring. Medicine to treat the dysrhythmia is not given preventively, but is kept ready for use if needed.

During a heart attack, there is always some degree of heart failure, although this may be so mild that it can only be detected by sensitive tests. If the heart failure is significant enough to cause clinical symptoms, however, it must be treated medically. A large number of inotropesmedications that improve the heart's pumping abilityare available to treat heart failure. Vasodilators, which decrease the pressure that the heart must pump against, may also be used to treat heart failure. During the early period after a heart attack, these medications are usually given intravenously, since this route allows them to work almost immediately.

A patient who develops heart failure will also require invasive monitoringcatheters inserted into some of the blood vessels to measure the pressures. An arterial catheter (small tube) is often inserted in the artery at the wrist. This monitor allows measurement of the exact blood pressure generated with each heartbeat. Arterial pressure measurements allow much more accurate monitoring than a routine blood pressure taken with a cuff and stethoscope. Complications from arterial catheters are very rare.
The catheters are threaded into the superior vena cava and right atrium of the heart, where they can measure the "filling pressure" of the heart. This allows doctors to determine the patient's fluid status. Too much fluid can worsen heart failure, while too little fluid does not allow the heart to fill properly. In about 2 percent of cases, the procedure of central venous catheter insertion causes a collapsed lung. If this occurs, another tube may be inserted into the chest to reexpand the lung.


If the heart failure is severe, it may become necessary to insert a pulmonary artery catheter. This catheter, similar in appearance to the central venous catheter, is inserted in the same place. A pulmonary artery catheter is quite long and is advanced through the right atrium and ventricle and into the pulmonary artery. This catheter allows very accurate determination of the pressures in the various parts of the heart. It can also be used to determine the cardiac output, the number of liters of blood the heart is pumping each minute. This information allows doctors to determine rapidly which medications will be of most benefit in treating the patient's heart failure.

Some heart attack patients may be treated differently, however. If a patient reaches a hospital within an hour or so after the symptoms of heart attack have begun, thrombolytic therapy may be started. Thrombolytic therapy is the use of clot-dissolving drugs in an attempt to remove the blood clot blocking the coronary artery. In thrombolytic therapy, one of several drugs may be given directly into a vein.
Thrombolytic therapy is based on the idea that heart attacks are usually caused by a blood clot forming over the plaque in a coronary artery. If the clot is dissolved, blood flow can be restored. This has to take place soon after the heart attack, before the myocytes have completely died. If thrombolytic therapy is given within two hours from the start of heart attack symptoms, almost 80 percent of patients will have restored blood flow to some degree. If it is given later than two hours, few patients will benefit.
There is currently a lot of controversy about how effective thrombolytic therapy is and when it is most useful. Most experts agree the therapy reduces mortality if used in the first hour. Most also agree that it does not appear to be very effective for persons over seventy-five years of age, or for diabetics. The therapy does have some risks, including allergic reactions to the medication and abnormal bleeding from other parts of the body. For this reason, the treatment cannot be used in persons at risk of bleeding (ulcer patients, for example).

Angiography may be performed soon after admission for a heart attack, or it may be delayed for a few days to allow the patient to stabilize. If angiography demonstrates multiple or particularly dangerous blockages, an emergency procedure such as angioplasty may be performed to relieve the obstruction.
Angioplasty (see chapter 9) consists of inserting a small balloon at the site of the blockage during cardiac catheterization, then inflating the balloon to flatten the plaque in the coronary artery. Attempts have been made to use angioplasty, in addition to thrombolytic therapy, to relieve the obstruction during a heart attack. It is still not clear for what cases this technique is beneficial or when it should be used.
A few heart attack patients are found to have such severe, widespread coronary artery disease that emergency coronary bypass surgery is performed almost immediately. This is usually reserved for cases when it is felt that the entire left main coronary artery, or several smaller coronary arteries, are so filled with plaque that the heart attack may spread to involve these areas.