Overview of Echocardiogram
Echocardiography is a test using ultrasound technology to get a close look at the heart’s structure without needing to perform an invasive procedure. The concept of echocardiography was first introduced in 1953 by Inge Edler, often referred to as the pioneer of echocardiography. He explained a type of echocardiography known as M-mode, which was the original technology.
M-Mode was created by merging two other types of ultrasound, A-mode and B-mode, together. This allowed doctors a glimpse into how the heart changed over time, though not in the form of a clear picture. As technology advanced, two-dimensional (2D) ultrasound was developed.
In 1973, S.L. Johnson came up with 2D ultrasound and added Doppler technology. Doppler technology helps doctors see how blood is flowing in our blood vessels. By 1979, Holen and Hatle discovered a way to detect pressure changes in the blood flow. Today’s echocardiography technology is a blend of all these developments.
Transthoracic echocardiography (TTE) is the most frequently used version of these techniques. It helps doctors to see the size, structure, and function of the heart in real time. To examine any abnormalities in how the heart’s walls move, doctors often use stress echocardiography which involves physically or chemically stressing the heart. Physical stress usually involves exercising like running on a treadmill and chemical stress involves medications.
When doctors want an even clearer picture of specific parts of your heart, such as the valves, they might use transesophageal echocardiography (TEE). This is a bit more invasive than TTE because it involves inserting a probe into the patient’s esophagus (the tube connecting your mouth to your stomach) to get pictures free from obstructions like muscle, tissue, and bone. There’s also another type called intracardiac echocardiography (ICE), usually used during heart procedures, for the highest resolution images.
Echocardiography is cost-effective, usually minimally invasive and widely available. It provides doctors with information that can alter a patient’s treatment plans, and sometimes bring to light life-saving information. Echocardiography is used across many areas of medicine and can be adapted to a broad range of situations. Different forms and combinations of this technique will be discussed later.
Anatomy and Physiology of Echocardiogram
Echocardiography is a commonly-used, non-surgical way to look at the heart and its parts. This test provides useful information about the different parts of the heart like the left and right atria (top chambers of the heart), left and right ventricles (lower chambers of the heart), heart valves and other structures related to these valves.
What makes echocardiography special is its ability to understand the behaviour of the heart’s blood flow. By integrating a technique known as ‘doppler’, doctors can spot any problems with the Heart valves, like narrowing (known as stenosis) or leakage (known as regurgitation). Echocardiography is also useful in checking how well the heart muscles work when they tighten and relax rhythmically to pump blood, known as systole and diastole respectively. This check plays a key role in stress tests which evaluates how the heart handles stress or exercise.
People who get unusual results in their stress echocardiography may be suggested to go through more specific procedures like cardiac catheterization, a procedure used to diagnose and treat certain heart conditions.
When performing echocardiography, doctors usually look at the heart from four standard angles or ‘views’. They are: the parasternal long axis, parasternal short axis, apical four-chamber, and subxiphoid views. Each of these views provides different perspectives of the heart and helps doctors to fully assess the heart’s function and structure.
The parasternal long-axis view, for example, is obtained by positioning an echocardiography device (probe) on the left side of the breastbone at the level of the 4th rib space. This view gives valuable information about the right and left ventricles, left atrium, and the exit route of blood from the heart, and their associated valves like the mitral, tricuspid, and aortic valves.
The parasternal short-axis view displays a cross-section of the left ventricle, useful for studying the heart wall function, while the apical four-chamber view helps to compare the ventricles and check for signs of strain on the right side of the heart that might occur due to serious blockage in lung blood vessels, known as a pulmonary embolism.
The subxiphoid view provides an overall picture of all heart chambers, the liver’s left lobe, and the large vein (inferior vena cava) that carries deoxygenated blood into the right side of the heart.
Apart from these, echocardiography is also helpful in assessing a patient’s hydration status. For instance, the compressibility of the inferior vena cava can tell us about the fluid status of the patient. If this vein can easily collapse by more than half, it means the patient could be dehydrated (low preload) and if not, the patient could be overloaded with fluid (high preload). However, this is not a sure-shot method and is often used along with other ways to check a patient’s fluid volume status.
Why do People Need Echocardiogram
Transthoracic echocardiography is a type of heart ultrasound that doctors often use when they suspect there might be an issue with a patient’s heart. This procedure is incredibly versatile and can help in diagnosing a variety of heart conditions.
Firstly, doctors may utilize this kind of ultrasound as a preventive measure in people who might not be showing any immediate heart-related symptoms, but have a family history of specific heart conditions such as hypertrophic cardiomyopathy (HCM), which involves a thickening of the heart muscle, or issues with aorta such as aneurysm or dissection. Similarly, athletes who show some abnormal changes in their ECG, a test that checks how your heart is functioning, might also benefit from an echocardiogram.
Secondly, an echocardiogram could be necessary if you’ve been experiencing symptoms like heart palpitations, feeling feint, shortness of breath due to exertion, or have been diagnosed with conditions like abnormal heart rhythms or blocked heart arteries.
Thirdly, if you already have heart failure or a valve disease, regular echocardiograms can provide vital information regarding your heart’s condition, which can inform your treatment plan. Especially in cases of Acute Heart Failures, echocardiograms can help assess the percentage of blood your heart is pumping with each beat – a measure known as the Ejection Fraction.
Finally, in the case of people who’ve had strokes, a procedure called a “bubble study” uses echocardiography to check for a common birth defect called Patent Foramen Ovale (PFO), where there’s a hole in the heart that didn’t close the way it should after birth. If this hole is identified as the cause for a stroke, it might need surgical closure.
Apart from these, bedside echocardiography is a handy tool used by doctors in the Intensive Care Unit or Emergency department. For instance, when a patient with shortness of breath is brought in, a quick bedside echocardiography can help doctors understand whether it was caused by heart failure, accumulation of fluid around the heart or some non-cardiac issue.
Stress echocardiography is another technique doctors use when they suspect you might have coronary artery disease such as stable angina (chest pain or discomfort due to blocked heart arteries). However, if your symptoms are severe, your doctors may decide to unblock your arteries using a procedure known as Percutaneous Coronary Intervention.
Doctors also use other specialized forms of echocardiography such as Transesophageal Echocardiography, Intracardiac Echocardiography, Intravascular Ultrasound, and Three-dimensional echocardiography when necessary to get a better view of different parts of the heart or to guide certain heart procedures. The choice of procedure would vary based on your specific condition.
Finally, there are layers of technical echocardiographic techniques such as strain rate echocardiography and contrast echocardiography, which can provide more information about the heart muscle’s movement and blood flow within the heart, under specific circumstances.
When a Person Should Avoid Echocardiogram
An echocardiogram, commonly known as an echo, is a test usually permitted for any patient, except if they choose not to have it. However, it’s important to know that the quality of the test results can depend on the patient’s body shape or size. In some cases, it may prevent the doctor from getting a clear picture or enough useful information.
There are, however, certain reasons why a patient may not be able to have some types of echocardiogram tests. Stress echocardiograms and transesophageal echocardiograms have certain limitations.
A stress echocardiogram tests your heart’s response to exercise. Some reasons a person might not have this test include:
– If they had a heart attack in the last two days,
– If they have severe aortic stenosis (a condition where the heart’s aortic valve narrows),
– If they have severe heart failure,
– If they have acute pericarditis (an inflammation of the sac-like covering around the heart),
– If they have uncontrolled arrhythmias (abnormal heart rhythm),
– If they have severe high blood pressure (more than 200/110 mmHg),
– If they have unstable chest pain and it’s not controlled with medicine.
A transesophageal echocardiogram involves a tube passing through your throat into your esophagus (the tube that connects your mouth and stomach) to get a closer look at your heart. The reasons a person might not have this test include:
– If they have esophagus disease with strictures or tumors,
– If they have an acute gastrointestinal bleeding (bleeding in your digestive tract),
– If they have diverticula (a condition where small, bulging pouches develop in your digestive system).
There’s also other situations where these tests might be avoided, such as:
– If they have hiatal hernias (a condition where part of your stomach bulges up through your diaphragm),
– If they suffered from face or airway injuries,
– Or if they had chest radiation.
These tests can still be performed considering the above conditions, but it requires a thorough discussion between the doctor and the patient about the potential risks and benefits. Invasive imaging techniques, which involve making a small cut or insertion into the body, have the same limitations as the procedures required to perform them, including cardiac catheterization (a procedure to examine how well your heart is working).
Equipment used for Echocardiogram
In a heart ultrasound (or transthoracic echocardiography), the devices used include an ultrasound machine capable of making images with the help of sound waves, a special heart ultrasound wand, and a specific type of gel to help the wand glide more easily and capture better images. If you’re going through a stress echo (a test that studies how your heart works under stress), your heart rate will need to be monitored with equipment and medicines, such as dobutamine, atropine, adenosine, and regadenoson, may be used to speed up your heart.
Meanwhile, if you are set for a transesophageal echocardiography, a more involved type of heart ultrasound that involves a tube being placed down your throat to capture clearer images of the heart, you might need a tube to be placed in your windpipe to help you breathe (tracheal intubation), as well as medicines to help you relax (sedation) and possibly medicines that briefly stop certain body movements (paralytic agents).
These procedures are normally done in a specialized room like an operating room, an endoscopy suite (a special room for tests that look inside your body), or a catheterization laboratory (a room designed to do tests and treatments that involve tiny, flexible tubes), under the watchful eyes of a heart doctor (cardiologist) and/or a doctor who specializes in anesthesia (anesthesiologist).
Who is needed to perform Echocardiogram?
An echocardiogram, which is a test that uses sound waves to create pictures of your heart, is often done by a specially trained technician known as a cardiovascular sonographer. In some places like the US, these technicians usually have a specific college degree. Once the pictures are taken, they need to be reviewed and understood. This job is done by a type of heart doctor called a cardiologist.
There’s another kind of echocardiogram called a transesophageal echocardiogram. Here, a small device is guided down your throat and into your esophagus (the tube that connects your mouth to your stomach) to get closer images of the heart. For this test, a specialist who knows how to help you sleep safely during the procedure, known as an anesthesiologist or a CRNA, is needed. The cardiologist will also be present during this procedure to make sure accurate images of your heart are taken.
If you need a more detailed look at your heart, you might have an invasive imaging test. An interventional cardiologist, who is a heart doctor specially trained to do heart procedures using a thin tube called a catheter, will need to be present. This test involves inserting a catheter into a blood vessel and gently steering it up to your heart.
However, in urgent cases like in the emergency department or in the intensive care unit, other types of doctors who are certified in doing and understanding echocardiograms may do these tests. They can then quickly decide on the right treatment based on the results.
Preparing for Echocardiogram
Having a transthoracic echocardiography, which is a heart scan, requires little preparation. Patients need to remove their upper body clothing and possibly heart monitoring stickers. They should also lie on their left side. Patient privacy is a priority, so they should be covered as much as possible. However, preparing for a transesophageal echocardiography, another type of heart scan, takes more effort. This procedure requires patients to be sedated, and the more complex cases might even need the patient to be placed on a breathing machine.
Also, if invasive imaging is done where doctors insert a device into veins located in the groin or wrist, those areas need to be carefully cleaned and covered with sterile drapes. Before any of these procedures begin, everyone involved in the process must double-check the patient’s name, birth date, and the specific procedure to be performed. This is to ensure everyone’s on the same page about what needs to be done.
How is Echocardiogram performed
When a doctor wants to do a heart test called transthoracic echocardiography, they will typically ask you to lie on your left side. This helps move your heart closer to the front of your chest, which makes it easier for the doctor to get a good ultrasound image. The doctor uses a special tool called a probe, which they move around on your skin at different places on your chest. The probe sends out sound waves that bounce off your heart and return to the probe, creating an image of your heart. It also avoids your rib bones, which can scatter the sound waves and disrupt the image.
For another type of heart test called transesophageal echocardiography (TEE), you will be asked to lie on your back with the head of the bed slightly angled. The doctor then places a bite block in your mouth, which ensures you can’t unnecessarily move or bite down on the probe. The probe for this test is a bit different – it gets inserted into your mouth and then moved down into your esophagus. This lets the doctor get an even clearer image of your heart because the sound waves have less body tissue to travel through.
During more invasive imaging procedures, doctors may also need to access blood vessels in your groin or wrist.
Possible Complications of Echocardiogram
Having a Transthoracic Echocardiogram (TTE), a test that uses sound waves to create pictures of the heart, is usually safe with very little risk. However, Transesophageal Echocardiography (TEE), another type of heart test done through the mouth and into the esophagus, does carry some risks like accidental tearing of the esophagus or bleeding.
If you’re getting a stress echocardiogram, where doctors monitor your heart while you exercise or use medication to make your heart work harder, there might be a chance of developing irregular heart rhythms.
Another type, Intracardiac echocardiography, where a small tube (catheter) is inserted through a vein and up into the heart, also carries a risk of bleeding because of the need for venous access. Also, there’s risk of accidental puncture to the heart or surrounding structures while the catheter is inside. This can cause a heart wall rupture, a blood-filled swelling (hematoma), fluid buildup in the heart (effusion), or sudden pressure buildup in the heart (tamponade).
What Else Should I Know About Echocardiogram?
Transthoracic Echocardiography (TTE) is used when shortness of breath or chest pain is probably caused by heart problems. This test can identify the severity and cause of any heart issues, size of heart chambers, and presence of heart valve diseases. It’s particularly useful for those with heart failure issues, as it guides the treatment plan. If the heart appears to be pumping at more than 50% of its usual capability, medications for symptom management are usually used. If the heart is pumping at less than 50%, additional medications are included to lower the threat of death. TTE is also used to check heart chamber pressures, to diagnose pulmonary artery hypertension, and to check for build-up of fluid around the heart (pericardial effusions) that may need an immediate intervention.
Bedside Echocardiography is useful for doctors to quickly gather information in urgent situations. It can even be used to check for lung clots or blockages, although it’s not completely reliable. If a patient isn’t able to retain enough fluid, this test can inform decisions about supplementing fluids through the veins.
Transesophageal Echocardiography (TEE) gives a clearer image of the heart valves which is in particular useful when there might be an infection. Before a patient can undergo a procedure to correct irregular heartbeats, TEE will also be used to check for any life-threatening blood clots. If no blood clots are found, the procedure can safely go ahead. TEE is also helpful in real-time during procedures within heart chambers.
Stress Echocardiography tests how well the heart works under stress by first examining it during rest and then after stress via an exercise or a medication. Any negative changes seen on the electrocardiogram or echocardiogram could suggest further treatment needed including heart procedure for opening up blocked arteries.
Intracardiac Echocardiography (ICE) isn’t used frequently due to its invasive nature and cost. It does, however, provide better heart imaging and can be useful in complex heart procedures. Its usage for left atrial appendage (a small internal heart structure) closure procedures isn’t ideal and further development in this area is needed.
Intravascular Ultrasound (IVUS), carried out during a cardiac catheterization, helps visualize the heart’s structure and any blockages. The type of treatment needed is determined by the percentage of blockage found in the heart arteries. If the blockage is less than 40%, intervention is not usually required, while a blockage greater than 70% would typically need intervention to open it up.
