ejection fraction the fraction of blood ejected from the heart
into the arteries, normally this ranges from 60 to 75%; a low
ejection fraction is less than 40%; often used as a marker of
ventricular contractility. heart failure failure of the heart to pump sufficient blood from
the chambers into the aorta; inadequate supply of blood
reaches organs and tissues. left ventricular dysfunction poor ventricular contractility, this
leads to heart failure. preload the degree of ventricular muscle stretch present at the
onset of myocardial contraction; often expressed as end
diastolic volume or pressure. venodilatation dilation of veins, as may occur during hot
weather, hot baths, and by some drugs such as ACE inhibitors
and nitroglycerin.
WHEN A HEART ATTACK BEGINS, THE individual is suddenly stricken by pain in the center of the chest. This pain is often unbearable and may be a pressure-like discomfort accompanied by difficult breath¬ing, profuse sweating, and a strange frightened feeling. The cause of a heart attack in the majority of cases is a blockage of a coronary artery that feeds the heart muscle with blood containing oxygen, glucose, sodium, potassium, calcium, and other nutrients. In more than 90% of patients, the blockage has been shown conclusively to be due to a blood clot. This blood clot is often present on the surface of a partially obstructing plaque of atheroma that shows fissuring (rupture or ulceration). The blocked artery cuts off blood to a segment of heart muscle (myocardium), the cells of which die because they are deprived of the nutrients in the blood. This death of heart muscle cells is called a myocardial infarction (see Fig. 1).

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• I. PERSPECTIVE
  More than one million patients have an acute myocardial infarction in the United States annually and more than 40% of these patients die within the first hour. Of those admitted to the hospital, approximately 15% die during hospitalization. Additionally, more than one million patients with symptoms suggestive of acute myocardial infarction are admitted annually to coronary care units. In the year 2000 more than 12 million people died because of cardiovascular disorders mainly caused by atheroma and subsequent thrombosis (atherothrombosis). It is estimated that in the year 2025 more than 24 million people will die from this disease in a world population of approximately 7.4 billion. Intensive research is required to prevent atherothrombosis rather than the management of its complications which include fatal and nonfatal heart attack, angina, heart failure, abdominal aortic aneurysm, stroke, kidney failure, and peripheral vascular disease causing intermittent claudication and gangrene of the lower limb.
• II. CAUSES AND PATHOPHYSIOLOGY
  The cause of a heart attack in the majority of cases is a blockage of a coronary artery by a blood clot. This clot usually occurs on the surface of a partially obstructing plaque of atheroma (see the figures in the chapter Atherosclerosis/Atherothrombosis). The surface of a plaque ruptures and the plaque contains substances that increase the clotting of blood. A clot therefore forms on the surface of the rupture and also inside the plaque. The ruptured plaque, by direct release of tissue factor and exposure of the subintima, is highly thrombogenic. Exposed collagen further provokes platelet aggregation. Some plaques, particularly those that have a high lipid content and a thin fibrous cap, are prone to rupture (see the chapter Atherosclerosis/Atherothrombosis). Considerable research has been done during the past decade on the complexity and the instability of vulnerable plaques.
• III. DOOR-TO-NEEDLE TIME
  As outlined above, in the majority of individuals the cause of a heart attack is a clot (thrombosis) in one of the coronary arteries. This clot can be dissolved by special drugs (thrombolytic agents). For this thrombolytic treat¬ment to be most effective, it should be given within three hours from the onset of the symptoms of a heart attack, that is, three hours from the onset of chest pain, which is the most common symptom. Beyond six hours, the chance of success with this treatment is remote, because the heart muscle cells become irreversibly damaged and die between four and six hours after the blood supply has been cut off. Many patients are given treatment from 6 to 12 h after the onset of their symptoms with the hope of saving a few lives. The number of lives saved by treating 1000 patients with thrombolytic therapy given at less than 1, 3, 6, and 12 h from the onset of symptoms are 65, 27, 25, and 8, respectively. Widespread advice to the population at risk is crucial. Less than 33% of heart attack victims presently receive therapy within four hours of the onset of symptoms.
• IV. SYMPTOMS
  The symptoms of a heart attack are often typical and easy to recognize. In some patients, however, symptoms can be so varied that both the patient and the doctor can be misled.
• V. PHYSICAL SIGNS
  During the examination of a patient the following physical signs and abnormalities may be observed:
• VI. MIMICS OF A HEART ATTACK
  Several conditions cause symptoms that can mimic heart attacks. These are the most common:
• VII. AMBULANCE TRANSPORT A. What to do Before the Ambulance Arrives
  If you think you are experiencing the symptoms and signs of a heart attack (see Section IV) you should get to the hospital emergency room as quickly as possible. Denial or wishful thinking that the pain will disappear in the next hour is about the worst thing you can do. Do not try to reach a physician for advice. Call the ambulance first, then ask someone to make a call to your doctor or cardiologist. If you cannot reach the doctor, leave a message; do not wait for a reply. If you are fortunate to live in an area where a mobile heart ambulance exists, then please use this service. If this is not available, use 911 or ambulance service. If no ambulances are available, have someone drive you immediately to an emergency room. Do not drive yourself to the hospital if you have pain lasting longer than 15 minutes, particularly if you have unusual profuse sweating, shortness of breath, dizziness, or feel weak.
• VIII. WHAT TO EXPECT IN THE HOSPITAL
  If you still have pain on arrival at the emergency room, you can be reassured that the pain will be relieved within five minutes. Usually no time is wasted. The emergency room staff are primed to move quickly to deal with ambulance cases, particularly those suspected to be heart attack victims. You are mainly expected to say to the nurse or the doctor that you are having chest pain. Point to the area of pain, indicating whether it is severe or very severe and that you are scared and would like something as soon as possible for the pain. You can then cooperate by answering all the other questions that the doctor may wish to ask. You will usually have to state whether you are allergic to medications. You will quickly receive an intravenous injection of morphine, which relieves the pain in two to five minutes. Because the injection is given intravenously, very small doses are used; for example, it may be given in 2-mg increments every minute until the pain is completely relieved. Do not be embarrassed to say that you are scared. A heart attack makes everyone afraid, and the doctor may sometimes forget this. Also, relief of pain by morphine can prevent some complications of a heart attack.
• IX. DIAGNOSTIC TESTS
  A. Electrocardiogram
• X. SPECIFIC MANAGEMENT
  A. Pain
• XI. CLINICAL TRIALS
  A. Meta-Analysis
• XII. NON-ST ELEVATION MYOCARDIAL INFARCTION
  A. Diagnosis
• XIII. COMPLICATIONS OF MYOCARDIAL INFARCTION
  A. Arrhythmias
• XIV. HEART ATTACK AND EMOTIONAL IMPACT
  For most people, suffering a heart attack is a traumatic mental experience. Uncertainty about the financial impact, the work situation, relationships, and in particular, sexual activity may cause depression and anxiety. Social workers, nurses, and the medical team must find time to listen and talk to the patient. Explanations and answers must be clear so that the patient understands that, after a heart attack, a normal life can be possible. The sophisticated gadgets of modern medicine cannot replace the reassuring words of an understanding, caring physician.
• XV. DEPRESSION AND ANXIETY
  The majority of heart attack patients experience some degree of depression and anxiety. To combat this complication, both the doctor and the nurses must communicate with the patient in an open and frank manner so that the patient can air feelings and have all questions answered during the time in the hospital. A social worker may have to be involved in some cases, and supportive home visits, advice on job orientation, and discussions regarding financial matters may be necessary. Two weekly visits to an understanding family doctor may help to dissipate depression with the recognition that all is not lost. The doctor should reassure the patient that depression and anxiety with the associated weakness and tiredness are normal and will be alleviated with time. It takes six weeks for the damaged muscle to heal and form a firm scar. During the same six weeks, anxiety and depression dissipate in the majority of patients. The first four weeks will be tough. Thereafter, the assistance of an exercise program, the ability to drive again, and the return of sexual activity may help to lift the despair. Time heals all wounds, including the muscle damage and psycholog¬ical insults. A few (less than 1% of patients) require anti-depressant drugs. These are nonaddicting and can be very useful when given as a single bedtime dose for 3 to a maximum of 12 weeks. An exercise rehabilitation program is useful in many respects and is of definite assistance in the management of most heart attack patients (see the chapter Depression and the Heart).
• XVI. DIET AFTER A HEART ATTACK
  A low-salt diet is prescribed only for patients with heart failure who require water pills (diuretics) or digoxin, as well as for the previously hypertensive patient (see Table 3). Patients are advised on the use of a weight-reduction diet and a modified diet to reduce cholesterol and saturated fat intake. Lipid-lowering drugs are administered to patients who have an LDL cholesterol greater than 100 mg/dl (2.5 mmol).
• XVII. REHABILITATION, RETIREMENT, AND TRAVEL
  Most patients under age 65 can return to work between 6 and 12 weeks after discharge. The return date takes into account the patient’s age, financial resources, existing diseases, and type of work. The physical and emotional stress associated with the job should be thoroughly explored.
• XVIII. RETIREMENT AND TRAVEL
  A. Retirement
• XIX. SEXUAL ACTIVITIES
  Sex is a part of living. For the majority, it is one of the most enjoyable, satisfying, stress-relieving activities that life provides. Most of what is said regarding heart attacks and sexual activity relates to men, because the heart attack rate is far more common in men than women at age 35–65. Also, men have far more hang-ups about sex than women, especially because a man cannot will an erection. Fear interferes with performance; thus some men, due to a lack of proper discussion with their doctor before hospital discharge, develop fears that may cause problems with sexual function. In addition, the female partner develops fear and apprehension that intercourse could cause the death of her husband. The female partner may therefore turn the whole thing off. This disturbance in a marital relationship can be quite traumatic and increase the anxiety and depression that is so common after a heart attack.
• XX. BETA-BLOCKERS
  Beta-blocking drugs were discussed in the chapter Angina, and the present discussion explains the rationale for their use in patients after a heart attack. Beta-blockers block the action of adrenaline and noradrenaline at receptor sites on the surface of cells. They cause a reduction in heart rate; therefore, less oxygen is required by the weakened heart muscle. They decrease the force of contraction of the heart muscles, and this further decreases the work and the amount of oxygen required by the heart. Most of the effects on the heart and arteries are related to this blocking of the actions of stress hormones. Beta-blockers stabilize the heart rhythm and can prevent premature beats such as those that are precipitated by mental and physical stress. They can prevent some episodes of ventricular fibrillation, which is the cause of sudden death.
• XXI. EPLERENONE (INSPRA)
  In the EPHESUS study reported by Pitt et al., eplerenone, a selective aldosterone blocker, administered to patients with left ventricular dysfunction after myocardial infarc¬tion proved beneficial. In the study 3313 patients were randomly assigned eplerenone, 25 mg daily to a maximum of 50 mg or placebo and 3319 patients were administered optimal medical therapy.
• XXII. CASE HISTORY OF A HEART PATIENT
  O.W., age 47, was sitting watching television when he suddenly felt a pain in the center of his chest. The pain felt like nothing he had ever experienced before. The entire lower two-thirds of his breastbone and part of his left chest felt as if someone was crushing him in a vice. He started to feel weak and afraid, and he loosened his collar to relieve the feeling of strangulation. He called his wife for some antacid for what he assumed must be terrible indigestion due to the high-fat meal he had eaten 30 minutes earlier. Two antacid tablets did not relieve the pain and he started
• XXIII. RISK FACTORS AND PREVENTION
  The identification of factors that increase the risk of heart attack has been made possible by various population studies including the well-known Framingham Study. Its statistical correlation has been consistent enough to enable researchers to state with confidence that high blood cholesterol, high blood pressure (hypertension), and cigarette smoking are major risk factors and, if present, increase your probability of having a fatal or nonfatal heart attack or stroke. These risk factors can be subdivided into three groups.
• XXIV. HEART ATTACK PREVENTION DIET
  Consult the tables in the Cholesterol chapter and follow the advice given in Sections A, B, and C below. This will fulfill the recommendation of fat intake to be 30% of food energy. You will receive enough polyunsaturated fat and protein without having to do complicated calculations. The American Heart Association Prudent Diet gives similar recommendations.
• BIBLIOGRAPHY
  Ambrose, J. A., D’Agate, D. J. et al. Plaque rupture and intracoronary