How Doctors Diagnose Heart Disease
"Diagnosis" is a term used in medicine and other professions to mean recognizing a problem and determining what it is. You cannot diagnose yourself, nor can your family or friends. Only physicians have the skills, training, and techniques to determine whether or not you have heart disease--the general term used to mean disorders of the heart and blood vessels.
This pamphlet has been written for the general public to describe the variety of procedures physicians may follow in the process of diagnosing possible heart disease. None of these procedures need be feared or considered mysterious; most are simple, short, straightforward, and painless. Some of these are very common and will probably be part of an office exam; others are special tests which are done in a hospital or clinic (most do not require staying overnight).
The Office Visit
You may have gone to a general or family practitioner or to an internist, or perhaps you've been referred by one of these cardiologist--a physician specializing in the diagnosis and treatment of heart disease. No matter what kind of physician you see, you can expect there to be certain basic elements of the office visit. These are a history and a physical exam, including a number of simple tests.
Basically, in these first visits, the doctor will be looking for the signs and symptoms of present heart disease and for risk factors which may help predict the chances of developing heart disease in the future.
Your physician will probably begin by talking with you and asking a series of questions about your present health and related factors, that is, he or she will be taking your "history." No even the computer, can replace this important form of human communication. A thorough history can provide 70 to 80 percent of the diagnosis; it can bring up and rule out various possible solutions and reveal which further tests need to be done. You can help your doctor take a good history by being as open and complete as possible.
The doctor will want to know what brought you to the office--what your "chief complaint" is--or, if this is a routine visit, whether you're having any problems. He or she will want to know the usual state of your health and what is different now. Many of the questions may concern the past and present condition of various body systems from head to foot.
The doctor will ask a brief health history of your family--your parents and other relatives--pertaining to a variety of disorders, especially those of the heart and vascular system, as these disorders sometimes seem to run in families.
He or she will want to know some of your social history, the kind of work you do, your education, etc., just to get a better idea of what you are like. He or she may ask you about your lifestyle, especially habits or characteristics which have been demonstrated to be risk factors for heart and blood vessel disease: whether you smoke, how much and how long; how much exercise you get; how stressful your life is; your diet, whether you eat or drink too much, whether you consume too much of fatty or salty foods.
The Physical Exam
Vital Signs: Your "vital signs" are your temperature, respiration and heart rates, and blood pressure. The doctor will measure your basal body temperature, count your rate of breathing or "respiration" and take your pulse (your heart rate as reflected by counting the expansions and contractions of an artery). Although the pulse is most commonly taken at one wrist, the doctor may compare the pulses in both wrists, the neck, the legs and other locations as an indication of how good your peripheral circulation in areas of the body beyond the trunk.
It is important that the doctor measure your blood pressure, the force of the flowing blood against the artery walls. It will be taken with an instrument called a "sphygmomanometer" or blood pressure cuff and will be expressed by two numbers, as for example 120/80 or "120 over 80." The upper number (higher pressure) is the systolic pressure, the pressure each time the heart contracts. The lower number is the diastolic pressure, the pressure each time the heart relaxes.
You can't feel what your blood pressure is, but if you have chronic untreated high blood pressure or "hypertension," you will eventually be aware of its results. A systolic pressure of 140 or higher or a diastolic of 90 or higher can strain the heart, can damage the arteries and can increase risk of heart disease, stroke and kidney disease. Fortunately, high blood pressure can be treated and controlled.
Height and Weight: Height and weight can be an index of obesity. Excess weight, beyond physical and skeletal requirements, can strain the heart and increase the chance of developing two major heart attack risk factors--high blood pressure and diabetes.
Auscultation: Auscultation is the act of listening to the sounds within the body, usually with a stethoscope, to determine the physical condition of the organs beneath. Your doctor may listen to the sound of your breathing and to the various sounds your heart makes as it beats.
Blood Tests: One blood test your doctor may do is to determine the levels of the blood fats (lipids), particularly cholesterol and triglycerides. High blood levels of these substances have been associated with atherosclerosis, hardening of the arteries by buildup of deposits of fatty materials, calcium and other substances along the inner wall of the artery. Clogged arteries can lead to heart attacks, strokes and other disorders. Another important blood test your doctor may do is to detect the amount of glucose or blood sugar in your blood to see if you may have diabetes. Diabetes mellitus is a strong risk factor for heart and blood vessel disorders.
Electrocardiogram: The electrocardiogram (ECG or EKG) gives a graphic representation of the electrical activity of the heart by means of a tracing produced on graph paper. It can reveal arrhythmias--irregular heart rhythms--and can provide information on the kind, extent, and location of injury sustained by the heart after a heart attack or other heart disorder. An ECG is most often taken while the patient is lying at rest. This is sometimes called a resting ECG. Your doctor may have an electrocardiograph, or ECG machine, to be able to take and read a tracing in his or her office. Or he or she may have you go to a clinic or hospital for this test.
Chest X-ray: A chest x-ray is created when an x-ray machine briefly sends minute amounts of radiation through the chest and onto a photographic plate. When developed, this "photo" will show the internal chest structures: ribs, lungs, heart and blood vessels. In cardiology, chest x-rays are useful in revealing enlargement of the heart--very often one sign of a chronic heart problem--and in detailing the circulatory system of the lungs. Some doctors, particularly cardiologists, have the staff and equipment to do a chest x-ray in their office; otherwise your doctor may order one to be done in a clinic or hospital facility.
Some diagnostic procedures are not done routinely in a doctor's office but in a medical center, because of the equipment and personnel involved. These procedures are resorted to when the more common procedures of the office examination cannot establish the diagnosis or when more detailed information on the nature, location, degree and physiological consequences of the disease or defect is needed to determine treatment. Whether any or all of these tests are performed depends on the judgment of your doctor or medical team and the nature of the problem.
Exercise Electrocardiogram: Sometimes called a stress test, this is an ECG recorded while the patient is exercising--usually walking or jogging on a treadmill or peddling on a stationary bicycle or perhaps walking up and down a short set of stairs. Because it requires exertion, this test is best done in the presence of a medical team in a well-equipped exercise lab. An exercise ECG can sometimes reveal heart ailments which show up only when the heart is under physical stress.
Fluoroscopy: Like chest x-rays, fluoroscopy involves visualizing internal organs by means of radiation. Instead of looking at still x-ray pictures, however, the physician can watch the heart's shadow in motion on a TV monitor hooked up to the fluorescent screen. Fluoroscopy can be useful for revealing irregularities in heart chamber size or function and calcification (hardening of valves and vessels). It is often used with other procedures, for example, cardiac catheterization. (Your doctor may be able to do fluoroscopy in his or her office, but chances are it will be done in a hospital setting).
Phonocardiography: Phonocardiography is the recording of heart sounds by microphones placed on the chest which are connected to sensitive recording equipment. For a visual record, the output signals from the microphone can be displayed on an oscilloscope and photographed, or can be automatically traced on graph paper.
Echocardiography: Echocardiography is similar in technique to sonar, which is used at sea to determine depth and location of underwater objects. Pulses of sound can be transmitted into the chest by means of small device placed on the skin. (This is harmless, high frequency "ultrasound" which cannot be heard by human ears.) The different echoes returning from the surfaces of the heart and other structures are then electronically plotted and recorded. These signals create an echocardiogram, a graphic image of the heart and blood vessels. This can yield useful information about these structures, such as the size, shape and motion of the heart chambers and great vessels and the motion of the heart valves.
Angiocardiography by Cardiac Catheterization: "Angiocardiography" means visualization of the heart, its vessels and chambers. Sometimes the shorter term "angiography" is used. When the technique is used only for arteries, it may be called "arteriography." Cineangiography or cinangiocardiography means that movies are made of the images. One method of angiocardiography is by cardiac catheterization. A catheter is a thin, flexible tube which can be guided into body organs. A cardiac catheter is made of material to which blood may not adhere, such as woven plastic. It is inserted into a vein or artery (usually of a leg or arm) and gently threaded to the heart while the doctor views its progress with a fluoroscope. Blood samples from the heart can be withdrawn through the catheter for laboratory chemical analysis. Blood pressure in the individual heart chambers, across heart valves or in the great vessels can be measured as well as the rate at which the blood is being pumped by the heart. Cardiac catheterization is the only one of these special techniques which requires hospitalization (for two or three days) as it requires a local anesthetic and observation after the test.
Angiocardiography by Radioisotopic Scanning: The heart, its vessels and chambers can also be visualized by radioisotopic scanning. This involves injection into the bloodstream of certain radioisotopes, substances which are slightly radioactive for a short period of time (a few hours or so). Using a sensitive device known as a gamma-scanner, the physician can detect and record the tiny amounts of radioactivity emitted as the radioisotope circulates through the heart chambers and great vessels. These records or scans aid in the evaluation of such factors as blood supply to the heart, size of the heart, amount of blood pumped per beat, and the extent of any heart muscle damage. This test may be done while the patient is resting or exercising.
Tests Being Developed: Much research is going into better and better methods of detecting heart disorders while they are "silent"--before symptoms such as chest pain or heart attack occur. Hopefully, there will be more refined ultrasound techniques which enable physicians to detect the beginnings of disease in the coronary arteries. There will also be greater use of the computer in putting together x-ray images of the heart. In general the trend is away from the entry into the body of a catheter, needle or other instrument and towards externally located instrumentation, such as is used in making echocardiograms, electrocardiograms, and radioisotopic angiocardiography.
Putting It All Together
All in all, your physician and the medical team assisting him or her have many methods they can use to diagnose you for possible heart disease. They will learn much by discussing with you your history and habits and by performing the physical examination including blood pressure, blood chemistries, and ECG, and other simple tests. They may make physiological measurements of the eating heart by recording electrical currents (on a rest or exercise ECG) or heart sounds by cardiac catheterization. Together, the procedures used should offer a very accurate picture of the health of your heart and blood vessels and enable you and your physician to know the proper course of treatment, if it is necessary. The procedures described here are the most common used to diagnose heart disease . If other conditions are suspected or found in the course of your examination, other tests may be required.
Risk Factors For Heart Disease
Risk factors are traits, habits, or conditions in individuals which are associated with an increased risk of developing "cardiovascular disease," disorders of the heart and blood vessels. Several risk factors have been identified. Some of the most important are:
These four have been clearly shown to be major independent predictors of risk. Two other important risk factors are a family history of heart disease and being male. Minor risk factors include obesity, a sedentary way of living and emotional stress. Your doctor will probably evaluate you for the presence of these characteristics and can give you advice on what you can do to improve your chances for good cardiovascular health.
The Warning Signals of a Heart Attack
It is important to know these symptoms, because if a heart attack occurs, there is no time for delay in getting medical care. A heart attack is not the same for everyone. One person may have intense pain, another may have milder indigestion-like discomfort, another may have no symptoms at all. The most common symptoms are:
These symptoms may also occur:
None, few of all of these symptoms may occur. Sometimes symptoms go away and then recur.
What To Do If Someone Has a Heart Attack
If someone develops the warning signs, act immediately. Call the doctor or emergency service right away (in many communities the number is 911). If you have trouble getting help by phone, get to a hospital emergency room at once. Minutes and even seconds can be crucial. If the person's heart stops, you can provide life support until professional help arrives by giving him cardiopulmonary resuscitation.
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