Overview of Cardiac Ultrasound
A cardiac ultrasound, also known as an echocardiography, is a simple and safe test that creates images of your heart. It is not invasive, meaning it doesn’t involve any injections or cuts to the body, and can quickly provide a lot of information about your heart’s health. This test can help your doctor see how well your heart is working, check the size of your heart and its chambers, and identify any problems that may exist.
The use of this test began in the 1960s when heart doctors, called cardiologists, started to use it to help diagnose heart problems. Later, emergency doctors also started to use this test as one of the many quick check-up options at their disposal to assess patients from head to toe.
Because the test was adopted by two different types of doctors at different times, there are two different ways to perform a cardiac ultrasound exam. But don’t worry, your doctor will choose the best approach for you based on your specific needs.
Anatomy and Physiology of Cardiac Ultrasound
The heart is located just behind and slightly to the left of the breastbone, with the upper chambers, or atria, angled towards the right shoulder. The lower chambers, or ventricles, are towards the front and lower part of the heart, ending roughly at the level of the left nipple. The right ventricle, which is the part of the heart that is furthest towards the front of the body, is typically found at the fourth space between your ribs.
The right upper chamber, or the right atrium, sends blood to the right lower chamber, or the right ventricle. This happens in a path from right to left and from top to bottom through a structure called the tricuspid valve. At the same time, the left upper chamber, or the left atrium, sends blood to the left lower chamber, or the left ventricle, via the mitral valve.
The large blood vessel called the ascending aorta carries blood away from the heart. It starts at the front of the left ventricle, goes behind the breastbone to the right, and then moves upwards and towards the patient’s left.
Why do People Need Cardiac Ultrasound
Doctors might ask for a heart ultrasound (cardiac ultrasound) for several reasons. Here are some of them simplified:
1. Chest pain:
If certain parts of the left chamber of your heart (left ventricle) are not contracting as they should, this may indicate a heart concern like acute coronary syndrome – a term for situations where blood supplied to the heart muscle is blocked.
If the right chamber of your heart (right ventricle) looks larger than the left side, and the heart wall is thicker than 5mm or the tricuspid valve (which separates the right ventricle and right atrium) has high velocity regurgitation (abnormal leakage), this might suggest chronic right heart strain – strain on this chamber of the heart over a prolonged period.
Seeing an independent moving mass in the right chamber or right atrium of the heart, or a McConnell sign (a movement disorder of the right ventricle of the heart), along with the chest pain or shortness of breath, may point towards a pulmonary embolism (a blood clot in the lungs). Finally, something called an intimal flap in the ascending aorta (part of your main blood vessel) or a dilated aortic outflow tract (wider than 4 cm) could suggest an aortic dissection – a severe condition where a tear occurs in the wall of the aorta.
2. Shortness of breath:
In some cases, shortness of breath can be explained by a pericardial effusion (fluid around the heart). It could also be due to a decreased left ventricle ejection fraction of less than 50%, which suggests congestive heart failure or myocarditis (an inflammation of the heart muscle). The list also includes acute coronary syndrome, pulmonary embolism, endocarditis (infection of the heart valve), or diseases of the heart valves.
3. Low blood pressure (hypotension):
An ultrasound can help diagnose conditions like a large pulmonary embolism, cardiogenic shock (a state where the heart can’t pump enough blood), pericardial effusion with compromised heart function, an aortic dissection, or a hyperdynamic squeeze that could suggest sepsis (a severe infection) or hemorrhagic shock (a state caused by too much blood loss).
4. Trauma to the chest:
It can also issue certain diagnostics following a serious chest injury caused by either a blow or an object penetrating the chest. Heart ultrasound can identify issues such as a cardiac contusion (bruise to the heart muscle) or pericardial effusion.
5. Cardiac arrest:
Heart ultrasound is useful when dealing with cardiac arrest. Being able to visually see the activity of the heart can help identify survivability following a specific type of cardiac arrest known as PEA arrest. The ultrasound could help spot reversible causes of cardiac arrest, such as pericardial effusion or a pulmonary embolism. Additionally, it helps check the quality of CPR (chest compressions) being given, particularly through a method called transesophageal echocardiography (heart ultrasound performed through the esophagus), which provides clearer views of the heart.
When a Person Should Avoid Cardiac Ultrasound
If someone is receiving CPR (cardiopulmonary resuscitation), a special type of heart ultrasound from the side of the chest (parasternal cardiac ultrasound) should not be performed. However, other views of the heart can be taken if possible. If the parasternal view is taken, it should be done during the pause to check the person’s pulse, and then cleaned up quickly before CPR begins again. Towels should be nearby to clean the gel used during the ultrasound. It’s also important to avoid scanning over any wounds or cuts to keep them from getting infected.
Equipment used for Cardiac Ultrasound
A heart ultrasound, also known as a cardiac ultrasound, is done with a special probe that uses low-frequency waves. To make sure we get an accurate picture of your heart, we use a small version of this probe that can easily fit between your ribs. The ideal type of probe for this is called a ‘phased array’.
The probe produces waves at a frequency that is higher than 20,000 Hertz (Hz). Hertz is just a measurement for frequency, similar to how kilometers or miles measure distance.
You may be wondering why we need an ultrasound of your heart. Simply put, it’s done to see how well your heart is performing. It allows us to see the structure of your heart, its valves and how blood is flowing through your heart. This is crucial for diagnosing potential heart problems and deciding on the best possible course of treatment.
Who is needed to perform Cardiac Ultrasound?
A cardiac ultrasound is a type of medical test that helps doctors see the heart and how it’s working. A healthcare professional who has received special training can carry out this test. For example, emergency doctors, once they have finished their period of intense study called residency, need to know how to perform and understand at least 25 to 50 of these heart ultrasound exams.
But it’s not just doctors who can do this. Many nurse practitioners and physician assistants – these are other types of healthcare workers who can diagnose illnesses and treat patients – are also skilled in doing this kind of heart exam.
Preparing for Cardiac Ultrasound
The patient should be lying flat on their back on a stretcher, with the top part of the bed slightly raised to about 30 degrees. For men, the chest area should be fully uncovered. For women, the hospital gown can be gathered up around the chest, and towels can be placed around the edges of the gown to keep it dry from the gel used for the ultrasound. If the patient isn’t wearing a gown, a towel can be draped over this area. This also applies to the set up for those who are right-handed. The ultrasound machine should be on the patient’s right side, powered, and turned on. If possible, the lights should be dimmed.
How is Cardiac Ultrasound performed
A cardiac ultrasound, also known as an echocardiogram, is a type of imaging test that uses sound waves to create pictures of your heart. This test helps doctors examine the structure and function of your heart. There are two common practices for performing this test. The first practice, established by heart doctors in the 1960s, involves the operator standing on the left side of the patient and adjusting the view of the ultrasound screen and probe according to the patient’s body. The second practice, often used by emergency doctors, keeps the viewing screen and probe in the same position for consistency and convenience when performing various procedures.
A cardiac ultrasound usually uses a low-frequency phased array probe, which is a hand-held device that sends and receives ultrasound signals. In a typical heart ultrasound, there are four crucial views, giving the doctors different perspectives to study your heart’s structure and behavior:
- Subxiphoid View: The probe is positioned under the xiphoid process (the lower part of the breastbone) and pushed up towards the heart. This view is useful for looking for a pericardial effusion, which is a buildup of fluid around the heart.
- Parasternal Long Axis View: The probe is placed to the left of the sternum (breastbone) and gives a lengthwise view of the heart. This view is great for examining the opening of the aorta (the main artery) and assessing the function of the left side of the heart.
- Parasternal Short Axis View: In this view, the probe is rotated to show a cross-section of the heart. It helps assess the function of the left side of the heart and look for signs of strain on the right side of the heart.
- Apical 4-Chamber View: Here, the probe is placed at the heart’s apex. With this view, the right and left parts of the heart can be compared to look for signs of strain.
Overall, a cardiac ultrasound helps your doctor make informed decisions about your heart health, particularly when dealing with issues like chest pain or breathing difficulties. Just remember, the test is non-invasive and should not involve any discomfort or risk.
Possible Complications of Cardiac Ultrasound
Having a cardiac ultrasound, which is a test used to look at the heart, is generally very safe. Like most ultrasound tests, it carries little to no risk. However, you may feel some discomfort during certain parts of the test. For example, when the doctor checks the view of all four chambers of your heart, they will press the ultrasound probe against your ribs, which might cause some discomfort.
What Else Should I Know About Cardiac Ultrasound?
Cardiac ultrasound is a simple, quick, and affordable tool that helps doctors identify and manage serious heart conditions. These include fluid accumulation around the heart (pericardial tamponade), acute coronary syndrome (a sudden reduction of blood flow to the heart), weakened heart muscle disease (cardiomyopathy), a blood clot in the lungs (pulmonary embolism), and Stanford type A aortic dissection (a severe condition where the inner layer of the aorta tears). In addition to diagnosing these conditions, a cardiac ultrasound can also help doctors understand the cause of shock and guide treatments. Importantly, the procedure is non-invasive, so it doesn’t require any surgery or injections.
