Echocardiography, also known as Echo or 2D Echo or echo-doppler is an ultrasound of the heart. This is a diagnostic test. This test is widely available and when done by a Cardiologist, it can give valuable insights into the heart’s functioning.
Echocardiography is of many types and following types are the widely used modalities.
2D Echo / Echocardiography
With Echocardiography we can see heart, we can measure various chambers of heart, we can see valves of the heart and analyse its function. Left-sided chambers of the heart are the main pump which decides the overall heart pumping function. We call this Left ventricular function. This is the main chamber of heart contributing to the pumping function of the heart.
Ejection Fraction ( EF )
Heart ejects blood out into a large blood vessel and this ejection, as a percentage of chamber volume, is called Ejection Fraction.
Normal ejection fraction is around 60%. It means if Left ventricular is filled with 100 ml of blood and it contracts normally, 60 ml of blood will be pumped out. Whenever any patient develops a heart attack, his left ventricular (read heart) pumping capacity goes down, from 60 to say 50 or 40%. And, when it comes down to less than 30 % suddenly, it can be fatal.
During Echocardiography we measure the speed of flowing blood across the heart chamber. This assessment is the Doppler test. This gives information about pressures within the heart. In patients with valve disease, the blood flow velocity across the valve increases unusually. So, Doppler can diagnose various valve diseases also.
You should be aware of these facts if you are undergoing echocardiography
Echocardiography is not a painful procedure, don’t be afraid of it.
It takes usually 10 min for the experienced operator to see the entire heart functions.
With echocardiography, we can not see blockages. This test can not diagnose what % blockages are there. Echocardiography can give past information. We can tell that patient had a heart attack or not, and if he had, what amount of permanent damage has occurred and what amount of damage can be reversed.
Normal echocardiography does not rule out any blockages.
Normal Echocardiography does not give any guarantee against future heart attack.
For valve disease patients, we do echo at regular interval to check the progression of valve disease severity.
We have seen over the years, many patients getting their echo every yearly, it is unnecessary. Once normal echo reported, it will become abnormal only after a heart attack. Doing it annually will not give any protection against heart attack. If your echo test is normal, TMT is normal, and you are doing good exercise, you probably do not require regular echo every 6 monthly. This gives a false sense of safety. Rather you should go for the treadmill test annually.
what will happen during echo
- You should wear loose clothing with buttons preferably. As this is a type of chest sonography, your privacy will be taken care of by the treating team.
- The doctor will ask to lie down on the side, conventionally on the left side.
- He will apply a gel over the probe and this probe will be applied over the chest to start imaging procedure.
- During the process, you can talk and you should breathe normally, but try to avoid deep breaths and excessive movement of the chest.
- At some of the points over the chest, the patient does feel little pain. This is very mild in nature and temporary.
- you may hear sound waves also when the doctor is using a velocity of the blood. Sound will be like the gush of air.
- After the completion of the test, wipe off the remains of gel and Doctor will discuss with you about the result of the test.
Stress Echocardiography / Dobutamine stress echo
Stress echocardiography also called an echocardiography stress test, stress echo or dobutamine stress test is a procedure that determines how well your heart and blood vessels are working.
This is an OPD based test. Cardiologist performs this test in his hospital or ICU. It normally takes between 45 – 60 mins.
The basic concept is that with increasing heart rate, the oxygen demand of working heart muscle increases greatly. In a normal individual, even at a heart rate of around 150 beats per minute, oxygen supply to the heart muscle is normal and so heart pumping function remains normal.
In patients with blockages in the blood vessel, with increasing heart rate, increasing oxygen demand is not met. Hence heart pumping abnormality starts as the heart rate increases. Earlier the abnormality – severe the disease.
During stress echocardiography, either you’ll exercise on a treadmill or stationary bike if you are fit, or you will be given a dobutamine drug to increase the heart rate (stress) on the heart and at the same time your doctor monitors your blood pressure and heart rhythm. At the time when your heart rate reaches peak levels, your doctor will take echocardiographic images of your heart to determine whether your heart muscles are getting enough blood and oxygen while you exercise.
When does the doctor advise Stress echo?
- If the patient can not walk on the treadmill due to his physical limitations and he needs Treadmill test.
- ECG abnormality is present at rest, so TMT could not elicit any new ECG abnormality
- In a patient requires a major surgery but the patient is homebound or Bedbound. For identifying the risk involved in giving anaesthesia, and for predicting whether the patient will be able to tolerate the stress of surgery, your doctor may advise stress echo/DSE as a preoperative investigation.
- After Cardiac procedure, we do this to see the patient’s fitness capacity.
How, Do I Prepare for a Stress Echo Cardiography Testing?
Before you take the test, you should do the following:
- Make sure not to eat or drink anything for three to four hours before the test.
- Don’t smoke on the day of the test because nicotine can interfere with your heart rate.
- Don’t drink coffee or take any medications that contain caffeine without checking with your doctor.
- If you take medications, ask your doctor whether you should take them on the day of the test. You shouldn’t take certain heart medications, such as beta-blockers before the test.
- If you are going for an exercise stress test then wear comfortable, loose-fitting clothes. Because you will exercise, make sure to wear good walking or running shoes.
What happens during stress echocardiography?
Your doctor needs to see how your heart functions while you’re at rest to get an accurate idea of how it’s working. Your doctor begins by placing 10 small, sticky patches called electrodes on your chest. The electrodes connect to an electrocardiograph (ECG).
The ECG measures your heart’s electrical activity, especially the rate and regularity of your heartbeats. You’ll likely have your blood pressure taken throughout the test as well.
Next, you’ll lie on your side, and your doctor will do a resting echocardiogram of your heart. They’ll apply a special gel to your skin and then use a device called a transducer or probe.
After the resting echocardiogram, your doctor will tell you to exercise on a treadmill or stationary bike if you are physically fit or-else you will be lying on a bed and doctor will start a dobutamine drug through a predetermined dosage as per your body weight and try to increase your heart rate to the desired level.
As soon as you reach your desired heart rate your doctor will take another echocardiogram. This is to take more images of your heart working under stress. You then have time to cool down until your heart rate can return to normal. Your doctor monitors your ECG, heart rate, and blood pressure until the levels return to normal.
What do the test results mean?
The echocardiography stress test is very reliable. Your doctor will explain your test results to you. Normal test means, your heart is working properly and your blood vessels are probably not blocked due to coronary artery disease.
Abnormal test results may mean that your heart isn’t pumping blood effectively because there’s a blockage in your blood vessels. Another reason could be that a heart attack damaged your heart.
Diagnosing coronary artery disease and assessing your risk for heart attacks early on can help prevent future complications. This test can also help determine if your current cardiac rehabilitation plan is working for you.
Any Risk during stress echocardiography?
This test is safe and noninvasive. Complications are very rare. The benefit of information outweighs the risk involved by miles.
Trans Esophageal Echo
What is Trans esophageal Echo, TEE, or TOE
This is an echocardiography study with an endoscope placed in the food pipe.
Our heart is covered on both sides by lungs containing air. Sound waves can not pass through these air pockets and hence visualisation of heart structure can be difficult in certain cases. Food pipe provides another window to see this heart structures. Here the endoscope is passed into the food pipe, placed just behind the heart.
Echocardiography probe is attached at the end of an endoscope. So now, we can see the entire heart from behind, with greater clarity and in full extent.
As it involves passing an endoscope into the food pipe, it is uncomfortable for the patient and hence routine use is discouraged.
When we advise TEE
However, in the following scenario, we recommend undergoing TEE for making a correct diagnosis and deciding further management plan
- Routine methods of echocardiography do not give good pictures due to lung diseases or thick chest walls
- The patient is having undiagnosed fever and the doctor is suspecting infection of heart valves.
- stroke ( paralysis ) patient and the Neurologist is suspecting a clot in the brain is coming from heart structures.
- The patient is having a hole in the heart and the cardiologist wants to close this hole with a device
Preparation for Trans esophageal echocardiography
- You need to take prior appointment for this test.
- We need empty stomach so 4 to 6 hours of fasting is desirable
- Basic blood tests depending on the individual patient’s profile
- What will happen during this test
- Doctor and Echocardiography technician will explain you the procedure
- You need to give written consent for the procedure
- The technician will apply local anaesthesia, this is a spray-applied in the mouth deeply. Taste of this spray may feel bitter and it can cause cough
- After 2-3 repeat spray, the actual procedure will be done
- The doctor will pass an endoscope through the mouth, you will be awake and you have to do mouth action as if you are swallowing food.
- Once the scope passes from the back of the mouth, further process is not painful
- You will not be able to speak during this procedure.
- Try to breathe from nose and not with your mouth
- Do not cough or pull out the scope, do not chew the endoscope tube. We may put tooth guard across the endoscope tube to prevent bite on the tube.
- The procedure will get completed within 5 minutes or so. After completion of taking pictures, the doctor will remove the scope slowly, at that time patient is likely to have a cough. Try to remove all secretions out.
- The patient will stay in observation for few minutes and then when comfortable, will be discharged.
- The doctor will discuss with you and your relatives about the finding of your test and you will be given a CD containing all the images for future reference.
I hope this information will help you when you are going to your cardiologist next.