Exercise Stress Test
Heart Disease Testing
• How Is Heart Disease Tested?
|How Is Heart Disease Tested?
As technology advances doctors have access to a wider range of medicals tests which can be used to diagnose heart disease in a safe and efficient manner. In cardiology (the medical specialty of treating heart disorders), cardiac (heart) tests help to confirm a clinical diagnosis as well as help predict a patient's survival chances (prognosis). They can also help a doctor determine the best course of treatment for a patient. That said, no scientific test has yet replaced the first and most important step of diagnosis: that is the physical examination combined with taking a complete medical history.
The Physical Examination: During the exam a doctor will carry out a visual inspection of the patient. For example they may notice a clue which suggests an overactive thyroid which could be responsible for a rapid heart beat. A particular type of growth on the eyelids could indicate high cholesterol levels and prominent neck veins could be indicative of heart failure and an excessive load on the right side of the heart. A blue tinge on the nails or tongue may be a sign of lack of oxygen in the blood. Next the physician places his hands on the patient's heart, feeling for the heart beat. Some loud heart murmurs can even be felt without the use of a stethoscope. Any palpations (fluttering's) felt in the belly area could indicate liver enlargement or an active ulcer. Next the doctor uses a procedure known as tapping or percussion. Placing one hand on the patient they use the other to tap on top. As solid and hollow areas of the body sound different, the tapping can help determine if any of the organs are enlarged. It also helps to diagnose fluid in the chest or abdomen. Finally the doctor uses a stethoscope to listen to the patient's heart beat, lungs and blood vessels. Any abnormal sounds are clues to the presence of heart disease.
Cardiac Tests: Deciding which type of diagnostic test is best can be difficult and advice can differ from doctor to doctor. There are non-invasive tests which do not involve inserting needles, fluids or instruments into the body. And there are invasive ones which range from a simple blood test to the insertion of a tube or scope and procedures such as open-heart surgery. Tests which are considered the gold standard for diagnosing heart diseases are not always appropriate for everyone. For example a cath (coronary angiography) is the gold standard for testing for coronary artery disease (CAD). Yet sometimes if a patient has stable (not worsening) CAD their doctor may manage their symptoms with medications rather than performing a cath because it is an invasive procedure with risks.
Electrocardiogram (ECG or EKG)
An electrocardiogram or ECG is a diagnostic tool which measures the electrical activity of the heart. Interpretation of those results can help diagnosis a wide range of heart diseases. An ECG is most commonly used for diagnosing a heart attack. When a heart attack has damaged an area of the heart, that area will have difficulties regulating concentrations of salt with every heart beat. This can be picked up by the ECG. It can also diagnosis previously undetected heart attacks. Although it may sound strange, almost one in three heart attacks go unnoticed by the patient. As a result, it is not uncommon for a specialist who is performing an ECG to uncover evidence of previous heart attacks. After a heart attack the damaged muscle cells become scar tissue and are no longer electrically active. An ECG can also be used to diagnose heart rhythm disturbances (heart arrhythmia). It can even show up conditions unrelated to the heart such as asthma and pulmonary embolism (a blot clot in the arteries of the lungs). An ECG is often recommended to patients who show symptoms such as chest pain (angina attack), dyspnoea (breathing difficulties), unexplained fainting spells and palpitations. During an ECG test, up to a dozen adhesive electrodes are stuck to specific locations on the arms, chest and legs. The test is completely painless and takes just a minute or two to perform once the electrodes are in place.
Patients with suspected heart disease may be submitted to a stress test to evaluate the heart’s ability to cope with increased demands. The results can help diagnosis the presence of heart disease. There are many different types of 'stress' tests, most often they involve some form exercise such as walking on a treadmill, stationary bike riding or performing arm exercises. Another type of stress test involves the use of chemicals. These chemicals are administered intravenously and make the heart work harder or dilate the heart's blood vessels. Both types of tests are usually monitored by either an ECG, echocardiogram or a highly technical PET image scan. Exercise stress tests are a non-invasive way to demonstrate cardiovascular disease (CDV). They can also help categorize patients who have already had a heart attack into high risk and low risk groups. For example a patient who can walk 15 minutes on a treadmill before developing chest pain (chest pain in women) has a better long-term prognosis (likely to live longer) than a patient who develops pain after 2 or 3 minutes. As coronary heart disease in women develops on average 10 years later than in men, some tests may be more appropriate for elderly women than others.
Exercise Stress Test
Chemical Stress Tests
In most medical centers women complaining of typical heart disease symptoms such as chest pain, are less likely to receive stress tests than men complaining of the same problems. Women's hearts seem to respond differently to men during stress tests. Very often women who show signs of heart disease on a stress test turn out to have very healthy hearts while women who show no signs of problems turn out to have blocked arteries. This high rate of false positives and false negatives may be attributed to the fact that the tests were only developed and validated on men.
An echocardiogram is a non-invasive diagnostic procedure (also known as an 'echo') used for taking detailed images of the heart (see pictures of the human body to locate the heart). It uses ultrasound technology to take images of the heart and surrounding tissues. The picture is more detailed than an X-ray but no radiation is involved. The procedure is painless and lasts about 30 minutes. The technician sticks electrodes to the patients body, this is to record their heart rate (ECG). Then a doppler or transducer which is covered in gel is applied to the chest. It sends out sound waves towards the heart, which bounce back and are recorded in images on a screen. The technician asks the patient to hold their breath at intervals and to roll onto different sides. The patient will be able to hear their blood flow through the heart. An echo is usually taken to confirm the diagnosis of heart disease after a physical examination. It may also be ordered to evaluate abnormal heart murmurs, unexplained chest pains, shortness of breath and palpitations. It is an important tool in particular for the diagnosis of heart failure.
This is an imaging technique which takes multiple X-rays by rotating around the body and uses a computer to convert them into 3-D images. Two different types of CAT scans are used for assessing cardiac problems. The first is the coronary artery calcification (CAC) score. This procedure tests for the level of calcium deposits in the coronary arteries. The higher the levels, the higher the risk of heart disease. If no calcification is noted it is very unlikely that CAD is present. The second test is called a CT angiography. This involves injecting contrast agents into the blood stream. Any blockages in the arteries are more likely to show up in a scan and the heart muscle can be viewed more easily. It is less invasive than the other alternative diagnostic test - heart catheterization - but it is also less accurate. Another problem with cardiac CAT scans is that they expose the patient to radiation, although newer methods are reducing this exposure.
A cath or cardiac catheterization (also called heart catheterization) procedure involves inserting a long thin hollow tube into a blood vessel to view the arteries. Very often the term 'cath' is commonly used to refer to one type of test - the coronary angiography. There are however in fact a number of different catheterization procedures for different purposes.
Left & Right Heart Catheterization
Biopsies are necessary for the accurate diagnosis of some types of heart disease and for monitoring patients after heart transplants. They are taken using a right heart catheterization procedure and essentially involve snipping a piece of heart muscle tissue for lab testing. Biopsies are only usually required in severe heart disease cases where the cause is unknown and treatment options depend on a specific diagnosis. Patients who have had heart transplants need to have regular biopsies to check for rejections. Identifying a rejection early is crucial because certain drugs can be used to limit damage to the transplanted heart.
Abnormal heart rhythms are usually checked with ECG’s. However some problems require an invasive procedure for diagnosis. An EP study usually involves a right heart catheterization. The cath has the ability to stimulate the heart with small amounts of electricity and to measure the heart's response. This procedure is useful for understanding complicated heart rhythm disturbances.
Your doctor can refer you to a cardiologist or will give you a list of chest pain clinics in your area.
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WOMENS HEALTH ADVICE: ABOUT HEART DISEASE IN WOMEN