Text. Control of Blood Pressure

The pressure in the arteries can be increased in various ways. For one, the heart can pump with more force, putting out more fluid each second. Another possibility is that the large arteries can lose their normal flexibility and become stiff, so that they can't expand when the heart pumps blood through them. Thus, the blood from each heartbeat is forced through less space than nor­mal, and the pressure increases. That's what happens in elderly people whose arterial walls become thickened and stiff because of arterio­sclerosis. Blood pressure is similarly increased in vasoconstriction—when the tiny arteries (arterioles) are temporarily constricted as a result of stimulation by nerves or by hormones in the blood. A third way in which the pressure in the arteries can be increased is for more fluid to be added to the system. This happens when the kid­neys malfunction and aren't able to remove enough salt and water from the body. The volume of blood in the body increases, so the blood pres­sure increases.

Conversely, if the heart's pumping activity di­minishes, if the arteries are dilated, or if fluid is removed from the system, the pressure falls. Ad­justments of these factors are governed by changes in kidney function and in the autonomic nervous system—the part of the nervous system that regulates many body functions automati­cally.

The sympathetic nervous system, which is part of the autonomic nervous system, temporarily in­creases blood pressure during the fight-or-flight response (the body's physical reaction to a threat). The sympathetic nervous system in­creases both the speed and force of the heart­beats. It also narrows most arterioles, but it ex­pands those in certain areas, such as in skeletal muscle, where an increased blood supply is needed. In addition, the sympathetic nervous sys­tem decreases the kidney's excretion of salt and water, thereby increasing the body's blood vol­ume. The sympathetic nervous system also re­leases the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline), which stim­ulate the heart and blood vessels.

The kidneys control blood pressure in several ways. If blood pressure rises, they increase their excretion of salt and water, which lowers blood volume and brings the blood pressure back down to normal. Conversely, if blood pressure falls, the kidneys decrease their excretion of salt and water, so that blood volume increases and blood pres­sure returns to normal. The kidneys also can increase blood pressure by secreting an enzyme called renin, which triggers the production of hormone called angiotensin, which in turn triggers the release of a hormone called aldosterone.

Because the kidneys are important in controlling blood pressure, many kidney diseases and abnormalities can cause high blood pressure. For example, a narrowing of the artery supplying one of the kidneys (renal artery stenosis) can cause hypertension. Kidney inflammation of various types and injury to one or both kidneys can also cause blood pressure to rise.

Causes

In about 90 percent of people with high blood pressure, the cause isn't known and the condition is referred to as essential or primary hyperten­sion. Essential hypertension probably has more than one cause. Several changes in the heart and blood vessels probably combine to elevate the blood pressure.

When the cause is known, the condition is called secondary hypertension. In 5 to 10 percent of the people with high blood pressure, the cause is kidney disease. In 1 to 2 percent, the cause is a condition such as a hormonal disorder or the use of certain drugs such as oral contraceptives (birth control pills). A rare cause of high blood pressure, pheochromocytoma is a tumor of the adrenal gland that produces the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline).

Obesity, a sedentary lifestyle, stress, and ex­cessive amounts of alcohol or salt in food all can play a role in the development of high blood pres­sure in people who have an inherited sensitivity.

Stress tends to cause the blood pressure to in­crease temporarily, but blood pressure usually returns to normal once the stress is over. This explains "white coat hypertension," in which the stress of visiting a doctor's office causes the blood pressure to raise high enough to be diagnosed as high blood pressure in someone who, at other times, has normal blood pressure. In susceptible people, these brief increases in blood pressure are thought to cause damage that eventually re­sults in permanently high blood pressure, even though the stress may no longer be present. This theory that temporary high blood pressure can give rise to permanent high blood pressure hasn't been proved.

Symptoms

In most people, high blood pressure causes no symptoms, despite the coincidental occurrence of certain symptoms that are widely—but erro­neously—believed to be associated with high blood pressure: headaches, nosebleeds, dizzi­ness, flushed face, and tiredness. Although peo­ple with high blood pressure may have these symptoms, they occur just as frequently in those with normal blood pressure.

If a person has high blood pressure that's se­vere or long-standing and untreated, symptoms such as headache, fatigue, nausea, vomiting, shortness of breath, restlessness, and blurred vi­sion occur because of damage to the brain, eyes, heart, and kidneys. Occasionally, people with se­vere high blood pressure develop drowsiness and even coma caused by brain swelling. This condi­tion, called hypertensive encephalopathy, re­quires emergency treatment.

Diagnosis

Blood pressure is measured after the person sits or lies for 5 minutes. A reading of 140/90 mm Hg or more is considered high, but a diagno­sis can't be based on a single high reading. Some­times, even several high readings aren't enough to make the diagnosis. If a person has an initial high reading, the blood pressure is measured again and then measured twice on at least two other days to make sure that the high blood pres­sure persists. The readings not only determine the presence of high blood pressure but also are used to classify its severity.

After high blood pressure has been diagnosed, its effects on key organs, especially the blood ves­sels, heart, brain, and kidneys, are usually evalu­ated. The retina (the light-sensitive membrane on the inner surface of the back of the eye) is the only place where a doctor can directly view the effects of high blood pressure on arterioles. The assumption is that the changes in the retina are similar to changes in blood vessels elsewhere in the body, such as the kidneys. To examine the retina, a doctor uses an ophthalmoscope (an in­strument that provides a view of the inside of the eye). By determining the degree of damage to the retina (retinopathy), a doctor can classify the se­riousness of the high blood pressure.

Changes in the heart—particularly enlarge­ment because of the increased work required to pump blood at the increased pressure—can be detected by electrocardiography and chest x-rays. In the early stages, such changes are best detected by echocardiography (a test that uses ultrasound waves to create an image of the heart). An abnormal heart sound, called the fourth heart sound, which can be heard with a stethoscope, is one of the earliest heart changes caused by high blood pressure.

Early indications of kidney damage are de­tected primarily by examining the person's urine. The presence of blood cells and albumin (a type of protein) in the urine, for example, can indicate such damage.

A doctor also looks for the cause of the high blood pressure, especially in a younger person, even though a cause is identified in less than 10 percent of people. The higher the blood pressure and the younger the patient, the more extensive the search for a cause is likely to be. The evalua­tion may include x-ray and radioisotope studies of the kidney, a chest x-ray, and examinations of blood and urine for certain hormones.

To detect a kidney problem, a doctor first takes a medical history, asking about previous kidney problems. Then during the physical examination, the area of the abdomen over the kidneys is checked for tenderness. A stethoscope is placed over the abdomen to listen for a bruit (the sound caused by blood rushing through a narrowing in the artery supplying the kidney). A urine speci­men may be sent to the laboratory for analysis, and x-rays or ultrasound scans of the kidney's blood supply and other tests of the kidneys are performed, if necessary.

When pheochromocytoma is the cause, break­down products of the hormones epinephrine (adrenaline) and norepinephrine (noradrenaline) show up in the urine. Usually, these hormones also produce various combinations of severe headache, anxiety, an awareness of a rapid or irregular heart rate (palpitations), excessive per­spiration, tremor, and paleness.

Other rare causes of high blood pressure may be detected by certain routine tests. For example, measuring the potassium level in the blood can help detect hyperaldosteronism, and measur­ing the blood pressure in both arms and legs can help detect coarctation of the aorta.

Prognosis

Untreated high blood pressure increases a per­son's risk of developing heart disease (such as heart failure or heart attack), kidney failure, and stroke at an early age. High blood pressure is the most important risk factor for stroke. It's also one of the three major risk factors for heart attack (myocardial infarction) that a person can do something about; the other two are smoking and high blood cholesterol levels. Treatment that low­ers high blood pressure greatly decreases the risk of stroke and heart failure. Such treatment may also decrease the risk of heart attack, although not as dramatically. Without treatment, fewer than 5 percent of people with malignant hyper­tension survive for a year.

Treatment

Essential hypertension can't be cured, but it can be treated to prevent complications. Because high blood pressure itself has no symptoms, doc­tors try to avoid treatments that make people feel bad or interfere with their lifestyle. Before any drugs are prescribed, alternative measures are usually tried.

Overweight people with high blood pressure are advised to reduce their weight to ideal levels. Changes in diet for those with diabetes, obesity, or high blood cholesterol levels also are impor­tant for overall cardiovascular health. Cutting down to less than 2.3 grams of sodium or 6 grams of sodium chloride a day (while maintaining an adequate intake of calcium, magnesium, and po­tassium) and reducing daily alcohol intake to less than 24 ounces of beer, 8 ounces of wine, or 2 ounces of 100-proof whiskey may make drug ther­apy for high blood pressure unnecessary. Mod­erate aerobic exercise is helpful. People with es­sential hypertension don't have to restrict their activities as long as their blood pressure is con­trolled. Smokers should stop smoking.

Often, doctors recommend that people with high blood pressure should monitor their blood pressure at home. Those who monitor their own blood pressure are probably more likely to follow a doctor's recommendations regarding treat­ment.

 

Notes:

erroneously ошибочно

awareness информированность

blurred vision затуманенное зрение

restlessness беспокойство

obesity ожирение

drowsiness сонливость

brain swelling отёк мозга

 

Atherosclerosis

Text.

 

Arteriosclerosis is a general term for several diseases in which the wall of an artery becomes thicker and less elastic. The most important and most common of these diseases is atherosclero­sis, in which fatty material accumulates under the inner lining of the arterial wall.

Atherosclerosis can affect the arteries of the brain, heart, kidneys, other vital organs, and the arms and legs. When atherosclerosis develops in the arteries that supply the brain (carotid arter­ies), a stroke may occur; when it develops in the arteries that supply the heart (coronary arteries), a heart attack may occur.

In the United States and most other Western countries, atherosclerosis is the leading cause of illness and death. Despite significant medical ad­vances, coronary artery disease (which results from atherosclerosis and causes heart attacks) and atherosclerotic stroke are responsible for more deaths than all other causes combined.

Causes

Atherosclerosis begins when white blood cells called monocytes migrate from the bloodstream into the wall of the artery and are transformed into cells that accumulate fatty materials. In time, these fat-laden monocytes accumulate, leading to a patchy thickening in the inner lining of the ar­tery. Each area of thickening (called an athero­sclerotic plaque or atheroma) is filled with a soft cheeselike substance consisting of various fatty materials, principally cholesterol, smooth muscle cells, and connective tissue cells. Atheromas may be scattered throughout the medium and large arteries, but usually they form where the arteries branch off—presumably because the constant turbulence at these areas injures the arterial wall, making it more susceptible to atheroma forma­tion.

Arteries affected with atherosclerosis lose their elasticity, and as the atheromas grow, the arteries narrow. With time, the atheromas collect calcium deposits, may become brittle, and may rupture. Blood may then enter a ruptured atheroma, mak­ing it larger, so that it narrows the artery even more. A ruptured atheroma also may spill its fatty contents and trigger the formation of a blood clot (thrombus). The clot may further narrow or even occlude the artery, or it may detach and float downstream where it causes an occlusion (em­bolism).

Symptoms

Usually, atherosclerosis doesn't produce symp­toms until it severely narrows the artery, or until it causes a sudden obstruction. Symptoms de­pend on where the atherosclerosis develops; thus, they may reflect problems in the heart, the brain, the legs, or almost anywhere in the body.

As atherosclerosis severely narrows an artery, the areas of the body it serves may not receive enough blood, which carries oxygen to the tis­sues. The first symptom of a narrowing artery may be pain or cramps at times when the blood flow can't keep up with the body's demand for oxygen. For instance, during exercise, a person may feel chest pain (angina) because of a lack of oxygen to the heart, or while walking, a person may feel leg cramps (intermittent claudication) because of a lack of oxygen to the legs. Typically, these symptoms develop gradually as the atheroma slowly narrows the artery. However, when an obstruction occurs suddenly—for example, when a blood clot lodges in an artery—the symptoms come on suddenly.

 

What Is Arteriolosclerosis?

Arteriolosclerosis is a less common type of arteriosclerosis that primarily affects the inner and middle layers of the walls of small muscular arteries (arterioles). This disease occurs mainly in people who have high blood pressure.

 

Risk Factors

The risk of developing atherosclerosis in­creases with high blood pressure, high blood cho­lesterol levels, cigarette smoking, diabetes, obe­sity, a lack of exercise, and advancing age. Having a close relative who developed atherosclerosis at an early age also puts a person at risk. Men have a higher risk than women, though after meno­pause, the risk increases in women and eventually equal that in men.

People with the inherited disease homocystinuria develop extensive atheroma formation, par­ticularly at a young age. The disease affects many arteries but doesn't primarily affect the coronary arteries, which supply the heart. In contrast, in the inherited disease familial hypercholesterolemia, extremely high levels of blood cholesterol cause atheromas to form in the coronary arteries much more than in other arteries.

Prevention and Treatment

To help prevent atherosclerosis, a person needs to eliminate the controllable risk factors— high blood cholesterol levels, high blood pres­sure, cigarette smoking, obesity, and lack of ex­ercise. So depending on a particular person's risk factors, prevention may consist of lowering cho­lesterol levels, quit­ting smoking, losing weight, and beginning an ex­ercise program. Fortunately, taking steps to achieve some of these goals helps achieve others. For instance, starting an exercise program helps a person lose weight, which in turn helps lower cholesterol levels and blood pressure. Quitting smoking helps lower cholesterol levels and blood pressure.

In people who already have a high risk of heart disease, smoking is particularly dangerous. Ciga­rette smoking decreases the level of good choles­terol (high-density lipoprotein cholesterol or HDL cholesterol) and increases the level of bad cholesterol (low-density lipoprotein cholesterol or LDL cholesterol). Smoking also raises the level of carbon monoxide in the blood, which may in­crease the risk of injury to the lining of the arterial wall, and smoking constricts arteries already nar­rowed by atherosclerosis, further decreasing the amount of blood reaching the tissues. Plus, smok­ing increases the blood's tendency to clot, so it increases the risk of peripheral arterial disease, coronary artery disease, stroke, and obstruction of an arterial graft after surgery. A smoker's risk of coronary artery disease is directly related to the number of cigarettes smoked daily. People who quit smoking have only half the risk of those who continue to smoke— regardless of how long they smoked before quit­ting. Quitting also decreases the risk of death after coronary artery bypass surgery or a heart attack. Additionally, quitting decreases illness and the risk of death in those who have atherosclerosis in arteries other than those that supply the heart and brain.

In short, the best treatment for atherosclerosis is prevention. When atherosclerosis becomes se­vere enough to cause complications, a doctor must treat the complications themselves—an­gina, heart attack, abnormal heart rhythms, heart failure, kidney failure, stroke, or obstructed pe­ripheral arteries.

 

Notes:

brittle хрупкий; нервный; нестабильный

patchy очаговый

spill проливаться, разливаться

presumably вероятно; предположительно

intermittent claudication перемежающаяся хромота

 

Coronary Artery Disease

Text A. Introduction.

Coronary artery disease is a condition in which fatty deposits accumulate in the cells lining the wall of a coronary artery and obstruct the blood flow.

Fatty deposits (called atheromas or plaques) build up gradually and are scattered in the large branches of the two main coronary arteries, which encircle the heart and supply it with blood; this gradual process is known as atherosclerosis. Atheromas bulge into the arteries, narrow­ing them. As the atheromas enlarge, portions may rupture and enter the bloodstream, or small blood clots may form on their surfaces.

For the heart to contract and pump blood nor­mally, the heart muscle (myocardium) requires a continuous supply of oxygen-enriched blood from the coronary arteries. But as an obstruction of a coronary artery worsens, ischemia (inade­quate blood supply) to the heart muscle can de­velop, causing heart damage. The most common cause of myocardial ischemia is coronary artery disease. The major complications of coronary ar­tery disease are angina and heart attack (myocardial infarction).

Coronary artery disease affects people of all races, but the incidence is extremely high among whites. However, race itself doesn't seem to be as important a factor as a person's lifestyle: specifi­cally, a high-fat diet, smoking, and a sedentary lifestyle increase the risk of coronary artery dis­ease.

In the United States, cardiovascular disease is the leading cause of death among both sexes, and coronary artery disease is the major cause of car­diovascular disease. The death rate is higher for men than for women, especially between the ages of 35 and 55. After age 55, the death rate for men declines, and the rate for women continues to climb. Compared with the death rates for whites, those for black men are higher until age 60 and those for black women are higher until age 75.

 

Notes:

obstruct препятствовать, затруднять

high-fat diet высококалорийное питание

sedentary lifestyle вести сидячий образ жизни

Text B. Angina

 

Angina, also called angina pectoris, is temporary chest pain or a sensation of pressure that occurs while heart muscle isn't receiving enough oxygen.

The heart's oxygen needs are determined by how hard the heart is working—how fast the heart is beating and how strong the beats are. Physical exertion and emotions make the heart work harder and thus increase the heart's oxygen needs. When the arteries are narrowed or blocked so that blood flow to the muscle can't increase to meet the need for more oxygen, ischemia may occur, resulting in pain.

Causes

Usually, angina results from coronary artery disease. But it can result from other causes, including abnormalities of the aortic valve, espe­cially aortic valve stenosis (narrowing of the aortic valve), aortic valve regurgitation (leakage of the aortic valve), and hypertrophic subaortic stenosis. Because the aortic valve is near the entrance to the coronary arteries, these abnormalities reduce blood flow through the coronary arteries. Arterial spasm (sudden temporary con­striction of an artery) may also cause angina, and severe anemia may reduce the supply of oxygen to the heart muscle, triggering angina.

Symptoms

Not everyone with ischemia experiences an­gina. Ischemia without angina is called silent ischemia. Doctors don't understand why ischemia is sometimes silent.

Most commonly, a person feels angina as a pres­sure or ache beneath the sternum (breastbone). Pain also may occur in the left shoulder or down the inside of the left arm; through the back; in the throat, jaw, or teeth; and occasionally down the right arm. Many people describe the feeling as discomfort rather than pain.

Typically, angina is triggered by physical activ­ity, lasts no more than a few minutes, and subsides with rest. Some people experience angina predictably with a certain degree of exertion. In other people, episodes occur unpredictably. Of­ten, angina is worse when exertion follows a meal. And it's usually worse in cold weather. Walking into the wind or moving from a warm room into the cold air may start an angina attack. Emotional stress may also cause or worsen angina. Some­times, experiencing a strong emotion while rest­ing or experiencing a bad dream during sleep can cause angina.

Variant angina results from a spasm of the large coronary arteries on the surface of the heart. It's called variant because it's characterized by pain while at rest, not on exertion, and by certain changes in the electrocardiogram (ECG) during an episode of angina.

Unstable angina refers to angina in which the pattern of symptoms changes. Because the characteristics of angina in a given person usually re­main constant, any change—such as more severe pain, more frequent attacks or attacks occurring with less exertion or during rest—is serious. Such changes in symptoms usually reflect a rapid pro­gression of coronary artery disease, with an in­creasing obstruction of a coronary artery because an atheroma has ruptured or a clot has formed. The risk of a heart attack is high. Unstable angina is a medical emergency.

Diagnosis

A doctor diagnoses largely by a person's description of the symptoms. Between and even during attack of angina, a physical examination or an ECG may reveal little, if anything abnormal. During an attack, the heart rate may increase slightly, blood pressure may grow up, and a doctor may hear characteristic change in the heartbeat while listening with a stethoscope. During an attack of typical angina, a doctor may detect changes in ECG, but ECG maybe normal between episodes, even in a person with extensive coronary artery disease.

When symptoms a typical, the diagnosis is usually easy for a doctor. The kind of pain, it's location, and it's association with exertion, meals, weather, and other factors may help a doctor make the diagnosis. Certain tests may help deter­mine the severity of the ischemia and the presence and extent of coronary artery disease.

Exercise tolerance testing (a test in which the person walks on a treadmill while being moni­tored by an ECG) can help in evaluating the se­verity of coronary artery disease and the ability of the heart to respond to ischemia. The results also may help determine the need for coronary arteriography or surgery.

Radionuclide imaging combined with exercise tolerance testing may provide a doctor with valuable information about a person's angina. Ra­dionuclide imaging not only confirms the presence of ischemia but also identifies the region and amount of heart muscle affected and shows the amount of blood flow reaching the heart muscle.

Exercise echocardiography is a test in which im­ages (echocardiograms) are obtained by bouncing ultrasound waves off the heart. The test is harmless and shows heart size, movement of the heart muscle, blood flow through the heart valves, and valve function. Echocardiograms are obtained at rest and at peak exercise. When isch­emia is present, the pumping motion of the wall of the left ventricle is abnormal.

Coronary arteriography may be performed when a diagnosis of coronary artery disease or ischemia isn't certain. However, most commonly, this test is used to determine the severity of coronary artery disease and to help evaluate whether the person needs a procedure to improve blood flow—either coronary artery bypass surgery or angioplasty.

In a few people with typical symptoms of angina and an abnormal exercise tolerance test, coronary arteriography doesn't confirm the presence of coronary artery disease. In some of these peo­ple, the small arteries in the heart muscle are abnormally constricted. Many questions remain about this condition, which some experts call syndrome X. Usually, symptoms improve when people with this.syndrome take nitrates or beta-blocker drugs. The prognosis for someone with syndrome X is good.

Continuous ECG monitoring with a Holter moni­tor (a portable, battery-powered ECG recorder) reveals abnormalities indicating silent ischemia in some patients. Doctors debate the significance of silent ischemia, but generally the severity of coronary artery disease determines the extent of silent ischemia and therefore the prognosis. An ECG also helps diagnose variant angina by detecting certain changes that occur when angina develops during rest.

Angiography (movie-type x-rays of arteries taken after a dye is injected) sometimes can detect spasm in coronary arteries that don't have an atheroma. Sometimes, certain drugs are given to produce the spasm during angiography.

Prognosis

Key factors in predicting what may happen to people who have angina include age, the extent of coronary artery disease, the severity of symp­toms, and, most of all, the degree of normal heart muscle function. The more coronary arteries af­fected or the worse the blockage of the arteries, the poorer the prognosis. The prognosis is surprisingly good in a person with stable angina and normal pumping ability (ventricular muscle function). Re­duced pumping ability dramatically worsens the outlook.

Treatment

Treatment begins with attempts to prevent cor­onary artery disease, to slow its progression, or to reverse it by dealing with its known causes (risk factors). Primary risk factors, such as elevated blood pressure and elevated cholesterol levels, are treated promptly. Cigarette smoking is the most important preventable risk factor in coro­nary artery disease.

Treatment of angina depends partially on the severity and stability of the symptoms. When symptoms are stable and mild to moderate, re­ducing risk factors and using drugs may be most effective. When symptoms get worse rapidly, im­mediate hospitalization and drug treatment are usual. If the symptoms don't markedly subside with drug treatment, diet, and lifestyle changes, angiography may be used to determine if coro­nary artery bypass surgery or angioplasty is feasible.

Stable Angina Treatment

Treatment is designed to prevent or reduce ischemia and minimize symptoms. Four types of drugs are available: beta-blockers, nitrates, cal­cium antagonists, and antiplatelet drugs.

Unstable Angina Treatment

Frequently, people with unstable angina are hospitalized, so that drug therapy can be closely monitored and other therapies can be used if nec­essary. These patients receive drugs to reduce the clotting tendency of blood. Both heparin, an anticoagulant that decreases blood clotting, and aspirin may be prescribed. Also, beta-blockers and intravenous nitroglycerin are given to reduce the workload of the heart. If drugs aren't effective, coronary arteriography and angioplasty or bypass surgery may be necessary.

 

Notes:

trigger способствовать началу

jaw челюсть

coronary artery bypass surgery аортокоронарное шунтирование

feasible возможный, осуществимый

 

Text C. Heart Attack

 

Heart attack (myocardial infarction) is a medical emergency in which some of the heart's blood sup­ply is suddenly severely restricted or cut off, causing heart muscle (myocardium) to die from lack of ox­ygen.

Some people use the term heart attack loosely, applying it to other heart conditions. But in this chapter, the term refers specifically to a myocardial infarction.

Causes

A heart attack usually occurs when a blockage in a coronary artery severely restricts or cuts off the blood supply to a region of the heart. If the supply is cut off or greatly reduced for more than a few minutes, heart tissue dies.

The heart's ability to keep pumping after a heart attack is directly related to the extent and location of the damaged tissue (infarction). Be­cause each coronary artery supplies a specific section of the heart, the location of the damage is determined by which artery is blocked. If more than half of the heart tissue is damaged, the heart generally can't function, and severe disability or death is likely. Even when damage is less exten­sive, the heart may be unable to pump adequately, resulting in heart failure or shock. The damaged heart may enlarge, partly to compensate for the de­crease in pumping ability (a larger heart beats more forcefully). The enlargement also may re­flect the heart muscle damage itself. Enlargement after a heart attack suggests a worse prognosis than a normal heart size.

A blood clot is the most common cause of a blocked coronary artery. Usually, the artery is already partially narrowed by atheromas. As dis­cussed, an atheroma may rupture or tear and cre­ate more blockage, which promotes clot forma­tion. The ruptured atheroma not only restricts the flow of blood through an artery, but also makes platelets stickier, further encouraging clots to form.

An uncommon cause of a heart attack is a clot from part of the heart itself. Sometimes a clot (embolus) forms in the heart, breaks away, and lodges in a coronary artery. Another uncommon cause is a spasm of a coronary artery that stops blood flow. Spasm may be caused by drugs such as cocaine or by smoking, but sometimes the cause is unknown.

Symptoms

About two out of three people who have heart attacks experience intermittent chest pain, shortness of breath, or fatigue a few days beforehand. The episodes of pain may become more frequent even after less and less physical exertion. Such unstable angina may culminate in a heart attack. Usually, the most recognizable symptom is pain in the middle of the chest that may spread to the back, jaw, or left arm; less often, it spreads to the right arm. The pain may occur in one or more of these places and not in the chest at all. The pain of a heart attack is similar to the pain of angina but is generally more severe, lasts longer, and isn't relieved by rest or nitroglycerin. Less often, pain is felt in the abdomen, where it may be mistaken for indigestion, especially because belching may bring partial or temporary relief.

Other symptoms include a feeling of faintness and a heavy pounding of the heart. Irregular heartbeats (arrhythmias) may seriously interfere with the heart's pumping ability or may cause the heart to stop pumping effectively (cardiac arrest), leading to a loss of consciousness or death.

During a heart attack, a person may become restless, sweaty, and anxious and may experience a sense of impending doom. The lips, hands, or feet may turn slightly blue. An elderly person may become disoriented.

Despite all the possible symptoms, as many as one out of five people suffering a heart attack have only mild symptoms or none at all. Such a silent heart attack may be recognized only on a routine electrocardiogram (ECG) some time afterward.

Diagnosis

Whenever a man over age 35 or a woman over age 50 complains of chest pain, a doctor usually considers the possibility of a heart attack. But several other conditions can produce similar pain: pneumonia, a blood clot in the lung (pulmonary embolism), inflammation of the membrane that surrounds the heart (pericardi­tis), rib fracture, spasm of the esophagus, indi­gestion, or chest muscle tenderness after injury or exertion. An ECG and certain blood tests can usually confirm the diagnosis of a heart attack in a few hours.

The ECG is the most important initial diagnostic test when a doctor suspects a heart attack. In many instances, it immediately shows that a per­son is having a heart attack. Several abnormalities may show up on the ECG, depending mainly on the size and location of the heart muscle damage. If a person has had previous heart problems that altered the ECG, the current muscle damage may be harder for doctors to detect. If a few ECGs over several hours are normal, a doctor considers a heart attack unlikely, but certain blood and other tests help in this determination.

The levels of certain enzymes in the blood can be measured to help diagnose a heart attack. An enzyme called CK-MB is normally found in heart muscle and is released into the blood when heart muscle is damaged. Elevated levels show up in the blood within 6 hours of a heart attack and persist for 36 to 48 hours. Levels of CK-MB are usually checked when the person is admitted to the hospital and at 6- to 8-hour intervals for the next 24 hours.

When ECG and CK-MB test results don't provide enough information, an echocardiogram or radio-nuclide imaging may be done. Echocardiograms may show reduced motion in part of the wall of the left ventricle (the heart chamber that pumps blood to the body), suggesting damage from a heart attack. Radionuclide imaging may show a persistent reduction in blood flow to a region of the heart muscle, suggesting a scar (dead tissue) caused by a heart attack.

Treatment

A heart attack is a medical emergency. Half of the deaths from heart attacks occur in the first 3 or 4 hours after symptoms begin. The sooner treatment begins, the better the chances of sur­vival. Anyone having symptoms that might indi­cate a heart attack should get prompt medical attention.

A person suspected of having a heart attack is usually admitted to a hospital that has a cardiac care unit. In the unit, the person's heart rhythm and blood pressure and the amount of oxygen in the blood are closely monitored to assess heart damage. Nurses in these units are specially trained to care for people with heart problems and to handle cardiac emergencies.

Initial Treatment. Usually, a person is immediately given an aspi­rin tablet to chew. This therapy improves the chances of survival by reducing the clot in the coronary artery. Because decreasing the heart's workload also helps limit tissue damage, a beta-blocker may be given to slow the heart rate and make the heart work less hard to pump blood through the body.

Often, oxygen is given through a face mask or a tube with prongs inserted into the nostrils. This therapy increases the oxygen pressure in the blood, which provides more oxygen to the heart and keeps heart tissue damage to a minimum.

If a blocked coronary artery can be cleared quickly, heart tissue may be saved. Blood clots in an artery often can be dissolved by thrombolytic therapy, using drugs such as streptokinase, urokinase, and tissue plasminogen activator. To be effective, the drugs are given intravenously within 6 hours of the start of heart attack symptoms. After 6 hours, some damage is permanent, and removing the blockage probably doesn't help. Early treatment increases blood flow in 60 to 80 percent of people and keeps heart tissue damage to a minimum. Aspirin, which prevents platelets from forming blood clots, or heparin, which also stops clotting, may enhance the effectiveness of thrombolytic therapy.

Because thrombolytic therapy can cause bleed­ing, it generally isn't given to people who have gastrointestinal bleeding, have severe high blood pressure (hypertension), have had a recent stroke, or have had surgery during the month be­fore the heart attack. Elderly people who don't have any of these conditions can safely receive thrombolytic therapy.

Some cardiovascular treatment centers use angioplasty or coronary artery bypass surgery right after the heart attack instead of thrombolytic therapy.

If the drugs used to increase coronary artery blood flow don't also relieve the patient's pain and distress, morphine is usually injected. This drug also has a calming effect and reduces the work of the heart. Nitroglycerin can relieve pain by reducing the work of the heart. Usually, it's first given intravenously.

Subsequent Treatment. Because excitement, physical exertion, and emotional distress place stress on the heart and make it work harder, a person who has just had a heart attack should stay in bed in a quiet room for a few days. Visitors are usually limited to fam­ily members and close friends. Watching televi­sion may be permitted if the programs don't cause stress. Smoking is a major risk factor for coronary artery disease and heart attack. Smok­ing is prohibited in most hospitals and is certainly prohibited in cardiac care units. Moreover, a heart attack is a compelling reason to stop smoking.

Stool softeners and gentle laxatives may be used to prevent constipation. If the person can't pass urine or if the doctors and nurses must keep track of the precise amount of urine produced, a bladder catheter is used.

Nervousness and depression are common after a heart attack. Because severe nervousness can stress the heart, a mild tranquilizer may be pre­scribed. To deal with mild depression and denial of illness, which are common after a heart attack, patients and their families and friends are encouraged to talk about their feelings with doctors, nurses, and social workers.

Drugs called angiotensin converting enzyme (ACE) inhibitors can reduce heart enlargement in many patients who suffer a heart attack. There­fore, these drugs are routinely given to patients a few days after a heart attack.

Prognosis and Prevention

Most people who survive for a few days after a heart attack can expect a full recovery, but about 10 percent die within a year. Most deaths occur in the first 3 or 4 months, typically in people who continue to have angina, ventricular arrhythmias, and heart failure.

To estimate whether a person will have more heart problems or needs additional treatment, a doctor may order certain tests. For instance, a person may have to wear a Holter monitor, which records the ECG for 24 hours, so a doctor can see if arrhythmias or episodes of silent ischemia are occurring. An exercise tolerance test (a test in which the person runs on a treadmill while being monitored by an ECG) before or shortly after discharge can help determine how well the per­son is doing after the heart attack and whether ischemia is continuing. If these tests reveal arrhythmias or ischemia, drug therapy may be rec­ommended. If ischemia persists, a doctor may recommend coronary arteriography to evaluate the possibility of angioplasty or bypass surgery to restore blood flow to the heart.

Many doctors recommend one baby aspirin, one half of an adult aspirin, or one full adult as­pirin daily after a heart attack. Because aspirin prevents platelets from forming clots, it reduces the risk of death and the risk of a second heart attack by 15 to 30 percent. People with an allergy to aspirin may take ticlopidine as an alternative. Doctors also prescribe beta-blockers because they reduce the risk of death by about 25 percent. The more serious the heart attack, the more benefit these drugs provide. However, some people can't tolerate the side effects, and not everyone benefits.

Rehabilitation

Cardiac rehabilitation is an important part of recovery. Remaining in bed for longer than 2 or 3 days leads to physical deconditioning and some­times to depression and a sense of helplessness. Barring complications, heart attack patients usu­ally progress to chair rest, passive exercise, walking to the bathroom and nonstressful work or reading by the third or fourth day after the heart attack. Most people go home after a week or less in the hospital.

Over the next 3 to 6 weeks, a person should slowly increase activity. Most people can safely resume sexual activity 1 or 2 weeks after leaving the hospital. If shortness of breath and chest pain don't occur, a full range of normal activity can be resumed after about 6 weeks.

After a heart attack, a doctor and patient should discuss risk factors that contribute to coronary artery disease, especially ones the patient can change. Quitting smoking, losing weight, controlling blood pressure, reducing blood cholesterol levels through diet or medication, and performing daily aerobic exercises all help reduce the risk of coronary artery disease.

Notes:

intermittent pain перемежающаяся боль

loss of consciousness потеря сознания

sense of impending doom чувство приближающегося конца (гибели)

resume возобновлять

EXERCISES

 

Exercise 1. Make up sentences of your own using the following words and phrases from the texts to the chapter “Abnormal Heart Rhythms”.

 

to work efficiently, reliably and continuously over a lifetime, to contract, the heart rate, to be physically fit, to occur, to persist, heart failure, coronary artery disease, to depend on, to be aware of smth., a stroke, to be more likely, to be responsible for, excessive bleeding, high blood pressure, to lead to smth., to be life threatening, to require emergency treatment, to pump blood, to respond to drug therapy.

 

Exercise 2. Study the text “Heart Failure” and say whether these statements are right or wrong. Correct them if they are wrong.

 

1. Heart failure is a serious condition in which electrical impulses are conducted along an extra pathway from the atria to the ventricles.

2. Heart failure has many causes, including a number of diseases, such as coronary artery disease and myocarditis.

3. Any disease that affects the blood vessels can lead to heart failure.

4. Left-sided disease leads to a swelling in the feet, ankles, legs, liver, and abdomen.

5. Sitting up causes the fluid to drain from the lungs, which makes breathing harder.

6. Smoking, being overweight and drinking alcohol all aggravate heart failure.

7. Excess dietary salt can cause fluid retention that counteracts the medical treatment.

8. A reliable way to check on the body’s retention of fluid is to check the salt content of packaged foods.

9. The most common symptoms of heart failure are weak and often rapid pulse rate, reduced blood pressure, an enlarged heart and liver, and a swollen abdomen or legs.

 

Exercise 3. Match each medical word or phrase with the common word or phrase that means the same.

 

1. anticoagulant cut

2. arrest tube

3. cardiac infarction clot

4. catheter loose stools (bowel movements)

5. diarrhea heart attack

6. etiology blood thinner

7. hypertension stoppage

8. laceration high blood pressure

9. thrombus cause; origin

 

Exercise 4. Learn the definition of the following special terms.

 

cardiovascular (circulatory) system – the system that carries blood to various parts of the body. It consists of the heart, blood vessels, and lymphatic system.

 

atria – the upper chambers of the heart. The left atrium receives oxygenated blood from the lungs; the right atrium receives deoxygenated blood from the rest of the body.

 

ventricles – the lower chambers of the heart, which when filled with blood, contract and propel it into the arteries.

 

aneurysm (alternate spelling: aneurism) – a localized abnormal dilation of a blood vessel due to a congenital defect or a weakness in the vessel wall.

 

infarction – the death of tissue in an organ following the cessation of blood supply. Myocardial infarction (death of part of the heart muscle) usually results from a thrombus (clot) in the coronary arterial system. Coronary thrombosis may also cause cardiac arrest (a sudden cessation of heartbeat).

 

hypertension – abnormally high blood pressure. Blood pressure is the pressure exerted by the blood on the wall of any vessel. What is considered normal varies somewhat with age and sex, but it is abnormally high when above 140/90.

 

Exercise 5. Discuss the meaning of the following special terms.

 

angina pectories, atherosclerosis, atrial fibrillation, tachycardia, cardiomyopathy, biopsy, endocardities, prolapse, stenosis, acute pericardities, hypotension, hypoglycemia, syncope, retinopathy.

 

Exercise 6. Write the medical meaning of each group of letters below.

 

MRI

ECY

AIDS

PTA

PMS

CT

MAST

HDL cholesterol

LDL cholesterol

 

Exercise 7. After each word part below, write its meaning. Then write a word which contains that word part. Use a dictionary for help.

 

1. athero-

2. cardi-

3. cerebr-

4. dys-

5. hyper-

6. hypo-

7. idio-

8. myc-

9. systole-

10. vas-

 

Exercise 8. Answer the following questions to the texts from Section “Heart and Blood Vessel Disorders”.

 

1. What are some important functions of the heart?

2. What causes atrial fibrillation?

3. What are the most common symptoms of cardiomyopathy (hypertension, hypotension)?

4. What are the signs of shock?

5. What is the difference between dilated congestive cardiomyopathy and hypertrophic cardiomyopathy?

6. What medicine is used to prevent hypertension (hypotension)?

7. What may be done in case of atherosclerosis?

8. What is the best treatment for atherosclerosis?

9. What is coronary artery disease?

10. Who is more susceptible to angina pectoris?

11. What causes angina?

12. What is the difference between variant and unstable angina?

13. What tests may help determine the severity of the ischemia and the presence and extent of coronary artery disease?

14. What does the medical term “the silent killer” mean?

 

Exercise 9. Match the half-sentences in column A with the half-sentences in column B to make correct and complete sentences.

 

A

1. Abnormal rhythms may be…

2. The most common cause of arrhythmias is…

3. Wolff-Parkinson-White Syndrome can cause…

4. Myocarditis may damage…

5. Excess dietary salt can cause…

6. Cardiomyopathy can be caused by…

7. The diagnosis is based on…

8. Pooling of blood in the swollen heart may cause…

9. Sudden death may result from…

10. A more common cause of mitral valve regurgitation is…

11. The diagnosis is based on…

12. Usually, acute pericarditis causes…

13. Fainting is a symptom of…

14. Low blood volume may result from…

15. Atropine may be used…

16. Untreated high blood pressure increases…

17. Atherosclerosis can effect…

18. Physical exertion and emotions make…

19. Cigarette smoking is…

20. A blood clot is…

21. During a heart attack, a person may become…

 

B

1. …fever and chest pain, which typically extends to the left shoulder and sometimes down the left arm.

2. …a person’s risk of developing heart disease, kidney failure, and stroke at an early age.

3. …an inadequate supply of oxygen and other nutrients to the brain.

4. …the arteries of the brain, heart, kidneys, other vital organs, and the arms and legs.

5. …the most important preventable risk factor in coronary artery disease.

6. …restless, sweaty, and anxious and may experience a sense of impending doom.

7. …the most common cause of a blocked coronary artery.

8. …severe bleeding, an excessive loss of body fluids, or inadequate fluid intake.

9. …the symptoms and a physical examination.

10. …the heart work harder and thus increase the heart’s oxygen needs.

11. …regular and irregular.

12. …fluid retention that counteracts the medical treatment.

13. …sudden episodes of a very rapid heartrate with palpitations.

14. …many known diseases, or it may have no identifiable cause.

15. …clots to form on the chamber walls.

16. …the heart muscle as may diabetes, or extreme obesity.

17. …heart disease, particularly coronary artery disease, and heart failure.

18. …the person’s medical history, physical examination, electrocardiogram, and chest X-ray.

19. …a heart attack, which can damage the supporting structures of the mitral valve.

20. …irregular heartbeats.

21. …to increase a slow heartbeat.

 

Exercise 10. Speak on the following.

 

1. Cardiomyopathy. Prognosis and Treatment

2. Low Blood Pressure. Drug Therapy.

3. Symptoms and Diagnosis of Shock.

4. Control of High Blood Pressure.

5. Atherosclerosis. Prevention and Treatment.

6. Heart Attack. Rehabilitation.

SECTION 3

Lung and Airway Disorders

Respiratory Symptoms

Among the most common symptoms of respiratory disorders are a cough, shortness of breath, chest pain, wheezing, stridor (a crowing sound when breathing), hemoptysis (coughing up of blood), cyanosis (bluish discoloration), finger clubbing, and respiratory failure. Some of these symptoms don’t always indicate a respiratory problem. Chest pain, for instance, may also reault from a heart or a gastrointestinal problem.

Note:

wheezing хрипы

finger clubbing симптом барабанных палочек

 

Text A. Cough

A cough is a sudden, explosive movement of air that tends to clear material from the airways.

Coughing, a familiar but complicated reflex, is one way in which the lungs and airways are pro­tected. Along with other mechanisms, coughing helps protect the lungs against particles that have been inhaled (aspirated). Coughing sometimes produces sputum – a mixture of mucus, debris, and cells expelled by the lungs.

Coughs vary considerably. A cough may be dis­tressing, especially if coughing episodes are ac­companied by chest pain, shortness of breath, or unusually large amounts of sputum, also called phlegm. However, if coughing develops over de­cades, as it may in a smoker with chronic bron­chitis, the person may hardly be aware of it.

Information about a cough helps a doctor de­termine its cause. Therefore, a doctor may ask

• How long it's been present

• What time of day it occurs

• Which factors - such as cold air, posture, talk­ing, eating, or drinking - influence it

• Whether it's accompanied by chest pain, breathlessness, hoarseness, dizziness, or other symptoms

• Whether it brings up sputum

A person may produce sputum without cough­ing, or a person may have a dry cough without sputum. The appearance of the sputum helps a doctor make a diagnosis. A yellowish, green, or brown appearance may point to a bacterial infec­tion. Clear, white, or watery sputum doesn't in­dicate a bacterial infection, but a virus, allergy, or irritant may be present. A doctor may examine the sputum microscopically; bacteria and white blood cells seen under the microscope are addi­tional indications of infection.

Treatment

Because coughing plays an important role in bringing up sputum and clearing the airways, a cough that produces a lot of sputum generally shouldn't be suppressed. Treating the underlying cause - such as an infection, fluid in the lungs, or an allergy - is more important. For example, an­tibiotics can be given for an infection, or antihistamines can be taken for an allergy.

Cough medicines can be used to suppress a dry cough (one that doesn't produce sputum) if it's disturbing. Also, in certain circumstances, such as when a person is exhausted but unable to sleep, cough medicines may be used to reduce a cough, even if it's bringing up sputum. A cough can be treated by two groups of drugs: antitussives and expectorants.

 

Notes:

airway воздухоносные пути

debris тканевой детрит

(фрагменты распавшихся тканей)

dizziness головокружение

hoarsness хрипота

suppress подавлять