When your doctor first suspects that you have heart disease you will be asked to undergo special tests so that the nature and severity of your specific disease can be diagnosed properly.
These tests can be divided into two categories-Invasive and
non-invasive. Invasive tests are those in which plastic tubes
called catheters are inserted through an artery or vein. Through
these catheters, dyes are injected arid blood samples removed,
pressure measured or electrical impulses are monitored. Non-invasive
tests are those in which the body is not penetrated by tubes,
wires or needles. Each of these two types of tests provide,
separate and important information.
When your Doctor first suspects that you have heart disease
you will be asked to undergo special tests so that the nature
and severity of your specific disease can be diagnosed properly.
These tests can be divided into two categories -Invasive and
non -invasive. Invasive tests ate those in which plastic tubes
called catheters are inserted through any artery or vein. Through
these catheters, dyes are injected and blood samples removed,
pressure measured or electrical impluses are monitored. Non-invasive
tests are those in which the body is not penetrated by tubes,
wires or needles. Each of these two types of tests provide,
separate and important information.
Blood Tests & Other Tests:
Certain enzymes are released into the blood when particular organs or muscles such as the heart are injured. Special blood tests can identify the presence of these enzymes. Together with information obtained through other tests, these enzyme measurements can often help to indicate whether the heart muscle has been damaged. This knowledge can help your physician to decide about the risks of Surgery.
In addition to the tests that specifically evaluate the heart, your doctor will probably want you to undergo other tests so your total circulatory system can be evaluated. These may include pulmonary (lung) function studies: blood cholesterol and triglyceride levels: blood sugar tests: tests for electrolytes (sodium, potassium chloride, magnesium etc.) present in the blood; and various tests for thyroid function, kidney function. A dental checkup also may be scheduled.
Non-Invasive Tests
Electrocardiogram (EKG, ECG): This is the most common non-invasive test and is usually performed during routine pysicalexaminations. Electrical activity generated by the contracting and relaxing of the heartmuscle is measured and recorded on a strip of moving paper. To accomplish this, metal electrodes attached to a recording machine are placed on your arms, legs and chest. No electricity enters your body; there is no discomfort. The EKG is simply a measuring device.
Exercise Test (Stress Test): This is also called the Treadmill test. Conventional or resting EKG is taken while you are at rest. The stress EKG is taken before, during and after a specific period of intense activity, such as pedaling an exercise bicycle or walking over a moving belt called treadmill. Your blood pressure and pulse are monitored before, during and after you have performed this activity. Certain normalities may become evident in stress testing that do not appear in a conventional EKG as the heart is requiring more oxygen-rich blood during exercise than at rest.
Echocardiogram:
The echocardiogram is a test that is used to evaluate
heart structures. The machine has a microphone like device
called transducer which is placed outside the chest wall,
this gives off ultrasound waves. The machine translates the
echoes of these waves to a picture on a piece of paper. The
"echo" of your heart structure can be measured.
Two-dimensional echocardiography is a more advanced technique
that not only records a diagram of heart motion, but provides
a video tape recording which pictures the entire heart, its
function and motion. Doppler echocardiography is an additional
unique technique that records the blood flow inside the heart.
The "echo" tells your doctor the thickness of heart
muscle. Certain abnormalities in the structure and function
of the heart valves and the heart wall, the presence of fluids
around the heart (pericardial effusion), and whether there
are tumors in certain chambers of the heart. Nowadays, Echocardio-gram
can also be done through your food tube "esophagus"
lying behind the heart, in order to get a more accurate picture
of the heart. This technique is known as "Transesophageal
echo (T.E.E.)" Other non invasive tests sometimes conducted
include the vector cardiogram and the HOLTER TEST (24 hour
ECG recording)
Thallium Scan/Stress Muga Scanning: This test is similar to the stress cardiogram. The reason this study is considered invasive is because prior to the initiation of exercise, you will receive an injection of a special tracer substance so that the outline of your heart, and how it responds to activity, will be recorded in a computerized fashion.
Invasive Test
Cardiac Catheterization and Angiocardiography:
By inserting a long tube or catheter through an artery or vein of an arm or leg into the heart, the physician can obtain important information that cannot be obtained in any other way. The procedure, usually performed while the patient is awake, and the patient is able to watch on television screen where the physician notes the progress of the catheter.
The catheterization is used to measure blood pressure and oxygen content in each of the heart's four chambers which can be used to withdraw blood samples from each part of the heart for testing. It can also identify any abnormal openings inside the heart, such as those, that are present in congenital heart disease, and so measure the heart's ability to contract and determine its output, or efficiency.
Coronary Angiography and Ventricular Function Assessment is frequently performed along with catheterization. A special non toxic dye is injected through the catheter and then an x-ray of the progress of this dye is recorded on motion picture film or CD. Depending on where the dye is sent, various heart abnormalities can be detected. For example by injecting dye into the main coronary arteries near the origin of the aorta, the complete arterial blood supply of the heart can be seen. Blocked arteries or partially blocked arteries can be identified. By passing the catheter through the aortic valve and injecting dye into the left ventricle the physician can evaluate how well the heart muscle contracts Ventriculography also permits detection of blood clots within the heart.
Diagrammatic depiction of coronary arteries, as will appear in the report your cardiologist will give you.
