• The many types of symptoms that are associated with myocardial infarction
• What you should do if you think you are having a heart attack
• The kinds of problems that myocardial infarction can cause
• What kinds of tests are done to see whether a person has an acute myocardial infarction
• What kinds of treatments are offered to a person suffering from acute myocardial infarction
• What kinds of tests are done on a person recovering from myocardial infarction
• What kinds of treatments are offered to a person recovering from acute myocardial infarction
• What the long-term picture looks like for a person who has had myocardial infarction

When people do have symptoms with their MIs, the symptoms can be quite mild (often in older people), can be severe (worst pain the person has ever had), or anything in between. See the patient_forum on angina for a list of the kinds of symptoms that are associated with angina. The symptoms of MI are similar, but often more severe. In addition (or instead), people having MI can have cold sweats, nausea and sometimes vomiting, lightheadedness or even loss of consciousness, and shortness of breath that can be very severe.

Thus, only a qualified physician should make the diagnosis of myocardial infarction. The diagnosis is hard to make accurately in some cases. The proof for this statement comes to two observations about contemporary practice in the United States. The first observation is that the leading cause of malpractice suits in the U.S. is when patients with acute MI are sent home by a doctor with a different diagnosis (for example, indigestion). The second observation is that the leading complaint of hospital administrators about emergency room doctors is that they are admitting too many people with the diagnosis of "possible myocardial infarction." The administrators find that most of these patients have some other diagnosis (for example, indigestion) when the case is investigated in the hospital. So, MI is a very hard diagnosis to make accurately even for well-trained physicians. The safest action is to treat all symptoms that might be MI as if they were a real MI until a qualified person says that they are not. Do not make this decision yourself unless you know what you are doing. In that case, remember that a doctor who treats him/herself has a fool for a patient.

Are we trying to scare you? No. We want you understand the reality of this disease as clearly as possible so that you can make informed decisions.

Mechanical complications include:

• cardiogenic shock, in which the heart muscle is too weak to pump enough blood to maintain adequate blood flow to the body. Most patients with cardiogenic shock die, but some can survive if proper treatment is begun promptly.

• pulmonary edema, in which the heart muscle is too weak to drain blood from the veins in the lungs. In this case, fluid crosses from the veins in the lung into the airspaces (alveoli) in the lung, and the person becomes short of breath. The severity of the pulmonary edema can vary from mild to life-threatening, and usually can be treated effectively if the proper diagnosis is made and if the heart muscle recovers function.

• rupture of the wall or a valve in the heart, with leakage of blood between the chambers of the heart or into the space around the heart. In this case, pulmonary edema or cardiac tamponade can develop. Either situation, the blood pressure can fall rapidly, and the person can die quickly unless accurate diagnosis and therapy occur quickly.

The major blood flow complication would be an increase in the size of the myocardial infarction, either in the same area as the original infarction or in a different area. This can sometimes be treated effectively.

The take-home lesson is that myocardial infarction is not a simple problem. Any infarction, no matter how small, can turn into a life-threatening situation over a matter of minutes. A person with acute myocardial infarction must be cared for in a cardiac intensive care unit by nurses with experience in this area supervised by physicians with specialty training in cardiovascular diseases. Only this degree of training and experience can ensure that problems can be recognized and treated before they kill the patient.

The initial diagnosis is based on the history (what the patient reports), the 12-lead electrocardiogram, and certain blood tests. In the first hours of symptoms, the history is the most important. The blood tests are the most definitive, but they are most sensitive only after 12 to 24 hours after the symptoms start.

The problem with the delay is that heart muscle begins to die within an hour after the symptoms start, and the process is complete in many people within six hours after symptoms start. It is very important to save as much muscle as possible in order to avoid problems during and after the acute phase of the infarction. Therefore, skilled physicians are aggressive in determining whether the symptoms represent a myocardial infarction (MI) or not.

When the symptoms suggest MI, the electrocardiogram supports the diagnosis, and other conditions do not interfere, many expert physicians proceed immediately with treatment for MI (see below). When the symptoms suggest MI strongly but the electrocardiogram does not support the diagnosis, many will recommend emergency left heart and coronary angiography (also called "catheterization"). This test allows the diagnosis of MI to be made with near-certainty. It also allows the physicians to proceed immediately with treatments that open blockages and restore blood flow in the heart.

When the symptoms suggest MI, but not as strongly, and when the electrocardiogram does not support the diagnosis, skilled physicians will often do an echocardiogram to look at the motion of the walls of the heart. The diagnosis of MI is supported when the echocardiogram shows that some parts of the heart walls move normally but others do not ("focal wall motion abnormalities"). If all parts of the heart walls move normally, the person could still be having an acute MI that does not affect a lot of heart muscle. In this situation, however, many good physicians will choose to wait for the blood test results rather than expose the person to the risks of emergency left heart and coronary angiography. Remember that we are talking about symptoms that are not particularly suggestive of acute MI. If the symptoms had been more suggestive, then the previous paragraph would have applied.

What kinds of treatments are offered to a person suffering from acute myocardial infarction

Many studies have been done to determine what the very best treatment is for this situation. The studies show that immediate treatment with asprin (160 mg chewed, not swallowed) is quick, safe, and somewhat effective. All patients with acute MI should be considered for treatment either with a thrombolytic ("clot buster") drug or with immediate angioplasty. This decision is a matter of professional judgement, and depends in part on the details of the case and the track record of the various parts of the hospital in getting things done.

Other medications may also be used, including heparin (a blood thinner), intravenous nitroglycerin (to help relax the coronary arteries), inotropic drugs (to help the heart pump more strongly if it has become too weak), and diuretic drugs (to help the kidneys get rid of excess water). The available data suggest that calcium blockers should not be used routinely in acute MI.

These tests may also be repeated after the person has recovered under some circumstances such as changing symptoms, a history of silent MI, or the need for on-going clearance for a stressful occupation.

• aspirin
• beta-blocking drugs (if tolerated)
• afterload-reducing drugs (if left ventricular function is impaired), and
• reduction in risk factors such as elevated cholesterol and use of cigarettes.

Monitored exercise rehabilitation certainly helps people feel better, and there is some evidence that it prolongs life.