Cardiac Diagnostic Tests

Early diagnosis of cardiac diseases plays a vital role in the treatment of heart problems. Various tests are available, which not only provides doctors the guidelines for deciding the course of treatment for their patients, but also gives prior warning to the patients for improving their lifestyle and taking preventive measures for minimising the risk of a heart disease.

RESTING ELECTROCARDIOGRAM (ECG)

Resting Electrocardiogram (ECG) is a simple test which is commonly used for basic evaluation of cardiac status. It records intrinsic electrical activity of the heart by placing electrodes on the limbs and chest. The recorded signals provide useful information regarding previous damage to the heart muscles, enlargement of heart chambers and abnormalities in the electrical system of the heart.

The most valuable role of ECG is in diagnosis and initial management of acute heart attack.

Preparations for the test

No special preparation is required.

AMBULATORY ECG (HOLTER) MONITORING

In this test, the Electrocardiogram (ECG) is continuously monitored for 24 to 48 hours. The signals are recorded on a special recorder which is worn by the patient. This prolonged monitoring records transient rhythm or EGG abnormalities. This test is especially useful in patients with palpitations, giddiness or fainting spells. It can also help in assessing response to drug therapy.

Preparations for the test

• There is no need for fasting or any other special preparation. Take all your prescribed medications as usual and record them in the diary provided. Wear loose fitting clothes while coming to the hospital.
• In the Holter room, surface electrodes will be placed on the upper chest. The electrodes will be connected to a recorder, the size of a small cassette player, which will be strapped around your waist. You will wear it continuously for 24 to 48 hours as requested by your physician. Please do not remove the electrodes on your own.
• You will be asked to keep a diary to record all your activities and any symptom with the exact time of their occurrence. Please carry out all your activities as usual except for bathing.
• You will be advised to return to the hospital at a given time to have the recorder removed for analysis. In case extended period of monitoring is required, a more specialized equipment called "Event Recorder" can be used. This mode of monitoring is particularly useful for patients who have very infrequent symptoms.

TREADMILL TEST (TMT) or EXERCISE STRESS TEST

Treadmill Test (TMT) assesses the response of your heart to increased workload and demand for blood. This is done by recording the ECG while you are walking on a treadmill machine.

Preparations for the test

• You may be asked to stop certain medications a day before the test. Please confirm this with your doctor.
• On the day of the test, do not eat or drink anything for at least four hours before the test.
• Please bring comfortable shoes and wear loose fitting clothes. For male patients, it may be necessary to shave the chest to allow for attachment of ECG electrodes.
• If you are suffering from fever or any other symptoms, please inform the doctor, so that you can be evaluated before the test.

Once you start walking on the treadmill, your blood pressure, heart rate, general condition and ECG will be monitored continuously. After every three minutes the speed and incline of the treadmill will be increased. You will be encouraged to exercise for as long as you can and the test will be continued till you reach a desired heart rate or cannot exercise any more. After the test, you will be asked to rest while ECG and blood pressure are recorded till your reach the baseline heart rate. All the recordings are analyzed by a cardiologist and the results made available in a few minutes.

Safety of the test

Exercise treadmill testing is very safe. Some patients might experience chest pain during the test. However, the risk of heart attack or abnormal heart beat is extremely low.

ECHOCARDIOGRAM

It is a diagnostic procedure performed by using ultrasound to take images and measurements of different parts of the heart

ADULT ECHOCARDIOGRAM

Preparations for the test

On the day of the test, you can eat or drink as usual and should take all prescribed medications. No special preparation is needed.

About the test

The test is performed by a cardiologist. You will be asked to change into a hospital gown. Gel is used for better contact between transducers and skin. The test will involve placing a transducer on the chest wall over the heart..

PAEDIATRIC AND FOETAL ECHOCARDIOGRAM

Echocardiography is an indispensable, non-invasive ultrasonic procedure used in the diagnosis and management of cardiac diseases in the fetus, newborns, infants and children. Preparations for the test

There is no need to withhold food or drink. Paediatric patients have to be quiet during the study. They may have to be sedated with a mild oral sedative, in which case no oral feeds should be given until the child is fully awake after the feed.

Fetal Echocardiogram is best performed between 20 and 24 weeks of gestation and no special preparation is required.

About the test

The test is performed by a cardiologist.

Safety of the test

At the present time, adverse effects resulting from application of diagnostic ultrasound have not been reported and the benefits to patients outweigh to risks, if any, that may be present.

STRESS ECHOCARDIOGRAM

Stress Echocardiography is a diagnostic test that uses ultrasound images of the heart to supplement ECG information obtained during a stress test. The results obtained by Stress Echocardiography are comparable to nuclear stress tests and are being used in major medical centres across the world to assess probability of coronary artery blockages or viability of damaged heart muscles.

Preparations for the test

• You should not eat or drink anything for at least six hours before the test. Take your medications as usual with a few sips of water, but do not take drugs called Beta-Blockers on the day of the test.
• Wear loose clothing and comfortable flat soled shoes.
• For male patients, it may be necessary to shave the chest before the test.
• If you are suffering from fever or any other symptoms, please inform the staff.

About the test

All stress tests are performed under supervision of a doctor. There are two forms of Stress Echocardiogram. If you are able to exercise vigorously on a treadmill, an exercise echocardiogram will be performed. The second method of stressing the heart is with administration of special medication intravenously that simulates exercise.

Safety of the test

Stress Echocardiography is a very safe test. However, some patients could develop chest pain, irregular heart beat or blood pressure changes. Stress Echocardiography is as safe as a regular nuclear exercise stress test. It gives the same type of information as a nuclear stress test, but without any radiation exposure.

TRANSESOPHAGEAL ECHOCARDIOGRAM (TEE)

It is a diagnostic procedure in which a tube with a tiny ultrasound probe is inserted through the patient's mouth and pictures of the heart are obtained using sound waves. The procedure is performed by an experienced cardiologist.

Preparations for the test

You should not eat or drink anything on the day of the test. If the test is in the afternoon, take your morning medicines as usual. If the test is the morning, do not take your routine medicines.

• Before the procedure, you will be asked to give written consent to perform the test. You should make arrangements for a responsible adult to take you home in the event that you receive sedating medications.
• After the test, you should not eat or drink anything for four hours and avoid driving if sedation was used.

How is the test done?

You will be asked to change into a hospital gown. Your throat will be sprayed with an anesthetic solution to numb it and you will be given an intravenous sedative if required. The TEE tube will be introduced through the mouth into the food pipe and stomach. Initially you will be asked to swallow repeatedly. This will facilitate passage of the tube to pass from the back of the throat and minimize discomfort. It takes 5-10 minutes to obtain different views of the heart.

After the procedure you will be observed for sometime before being allowed to go home. It is not unusual to feel some soreness in the throat for one or two days after the test.

Safety of the test

TEE is a semi-invasive procedure and carries a small risk of trauma to the food pipe or throat.

AMBULATORY BLOOD PRESSURE MONITORING

Occasional blood pressure measurements taken at home or in a clinic at times do not provide adequate information and your physician may ask for this test. This test monitors blood pressure on an hourly basis for 24 hours and readings are recorded on a special recorder. These readings are then analysed by sophisticated equipment and the results are interpreted by an experienced cardiologist.

Preparations for the test

• Patients should take their meals and medications regularly.
• Wear clothes with loose sleeves.
• Equipment consists of a recorder, the size of a small cassette player and a blood pressure cuff, which is applied to the arm. You will wear the cuff continuously for the duration of the test. The cuff will inflate automatically every hour to record your blood pressure.
• Please carry out all your activities as usual except bathing.
• You will be asked to keep a diary to record all your activities and any symptom with the exact time of its occurrence.
• You will be instructed to return to the hospital at a given time to have the equipment removed.

HEAD-UP TILT TABLE TEST

Some patients complain of dizziness or episodic loss of consciousness, with no obvious cause for it. This special test is performed to discern the cause. During the test, patient is tilted head up to a certain angle for up to 45 minutes, while heart rate, ECG and blood pressure is continuously monitored. Any change in heart rate, blood pressure or recurrence of symptoms is carefully observed.

How is the test done?

• You should be fasting for eight hours before the test. Your physician might instruct you to stop some medications before the test.
• You can take prescribed medicines with few sips of water. Wear loose fitting clothes.
• You will be asked to be flat on the tilt table.
• Electrodes for ECG monitoring will be placed on the chest, while blood pressure cuff will be placed on one arm and IV cannula in the other arm.
• After recording blood pressure, pulse and baseline ECG in supine position, restraining straps will be placed over you and the table will be tilled to 45-60 degree with head up.
• ECG and heart rate will be continuously monitored and blood pressure will be recorded after every 3-5 minutes. The test will be terminated if you complain of dizzy feeling and if blood pressure or heart rate drops below a certain level. If no significant changes occur, the test will be stopped after 45 minutes. You will be observed for some time before being allowed to go home.

Safety of the test

Some patients have unpleasant feelings during the test. However, rest assured that this is a very safe test