Echocardiogram

Generality

An echocardiogram is an "ultrasound of the heart and, in fact, involves the use of an ultrasound probe very similar to that used in normal muscle tendon ultrasound examinations.
Cardiologists use echocardiography when they suspect the presence of a heart disease, such as myocardial damage, heart failure, valvular disease or a congenital heart defect.

There are at least 4 different types of echocardiography: the transthoracic (or standard) echocardiogram, the transesophageal echocardiogram, the color-Doppler echocardiogram and the exertion (or stress) echocardiogram.
In general, preparation and risks of the procedure depend on the type of echocardiogram expected.
The results of the procedure are usually available after a few days.

Brief anatomical recall of the heart

The heart is an unequal organ that finds its place in the rib cage, on the left center. Anatomically, it can be divided into two halves, the right half and the left half.
The right half comprises two overlapping cavities, the right atrium, at the top, and the left ventricle, at the bottom.
The left half is very similar to the right half and also includes two overlapping cavities, which are the left atrium, above, and the left ventricle, below.
Central organ of the circulatory system, the heart receives and sends the blood circulating in the human body, through a series of blood vessels:

• The hollow veins, which introduce non-oxygenated blood into the right atrium.
• The pulmonary arteries, which branch off from the right ventricle and carry non-oxygenated blood to the lungs.
• The pulmonary veins, which carry oxygenated blood into the lungs inside the left atrium.
• The aorta, which departs from the left ventricle and carries oxygenated blood to the various organs and tissues of the human body.

What is the echocardiogram?

An echocardiogram, or echocardium, is a diagnostic test that - through the use of an ultrasound probe - allows the doctor (to be precise a cardiologist) to visualize the heart, the blood vessels associated with it and the blood flow to it. "interior of the heart cavities (atria and ventricles).
Since the ultrasound probe is very similar to the probe used during normal ultrasound examinations, the echocardiogram can also take the definition of ultrasound of the heart.

HOW DOES AN ULTRASOUND WORK?

During an "ultrasound", doctors make use of an instrument called an ultrasound.
An ultrasound system comprises three main elements: a computerized console, a monitor, and an ultrasound probe (called a transducer).
The ultrasound probe is the element of the three which, resting on the body, allows the organs and tissues below the examined area to be viewed on the monitor (after processing by the computerized console).
The transducer works like this: thanks to the passage of alternating electric current, the probe produces a certain amount of ultrasound; these penetrate through the skin and affect the underlying tissues (or organs). A portion of the penetrated ultrasounds is subject to refraction - that is, it is absorbed by the tissue - while another portion is subject to reflection, that is, it goes back towards the transducer.
In hitting the probe, the reflected altitude (also called "echo") generates an electric current, which the computerized console can interpret and transform into images on the monitor.
The resolution of the images depends on the ultrasound emission frequency: the higher this frequency, the greater the penetration of the ultrasound into the tissues and the better the resolution.

Uses

Generally, doctors prescribe the execution of an echocardiogram when, following a certain symptomatology, they suspect the presence of heart disease.
In this case, an echocardiogram allows us to identify:

• Damage to the myocardium (i.e. the heart muscle) caused by a heart attack (or myocardial infarction). Following a heart attack, the blood supply to the myocardium is less than required and this leads to the death (or necrosis) of the tissues most affected by ischemia.
• A state of heart failure. With heart failure, cardiologists indicate the heart's ineffectiveness at adequately pumping blood to various organs and tissues in the body.
• Congenital heart defects. The word "congeniti" means "present from birth". Thus, congenital heart defects are anatomical anomalies of the heart present from the first day of life and the result of a developmental error during intrauterine life.
• A valvulopathy. By valvulopathy, cardiologists mean any functional or structural alteration that affects the heart valves. There are four heart valves in all and are those elements that, in the heart, regulate the passage of blood between the various heart cavities (ie between the atria and ventricles) and between the ventricles and the vessels that branch off from them.
• A cardiomyopathy. Cardiomyopathies are morbid conditions characterized by first anatomical and then functional alterations of the myocardium, which involve a reduction in the contractile activity of the heart.
• An "endocarditis. Endocarditis is the medical term for" inflammation of the endocardium (the inner lining of the myocardium) and heart valves.
  Endocarditis are often conditions of infectious origin, to be precise bacterial.

Clearly, the identification of the aforementioned conditions through the echocardiogram has important implications in the therapeutic field: the knowledge of the heart disease in progress allows to plan the most adequate treatment.

Types

There are at least four types of echocardiography:

• The transthoracic echocardiogram. Also known as the standard echocardiogram, it is the most practiced type.
• The transesophageal echocardiogram. Provides more accurate images of the heart and associated vessels than a transthoracic echocardiogram. However, this accuracy comes at a price in terms of greater invasiveness.
• The color-Doppler echocardiogram. Executable both in transthoracic and transesophageal modality, it allows to highlight and study the blood flow (ie the blood flow) inside the heart and the vessels arriving and departing from the latter. color-Doppler technology distinguishes with different colors the direction of blood flow through the various cardiac cavities: on the monitor, the blood directed towards the transducer is colored red, while the blood moving away from the transducer is colored blue.
• The stress echocardiogram (or stress echocardiogram or stress echocardiogram). It is an echocardiogram performed on a person who has just undergone physical activity of a certain intensity. It serves to see what the heart is doing during an effort.
  If the patient is unable to carry out any physical activity (for example he is a very elderly person), doctors resort to the administration of some particular medicines, which strain the heart like physical exercise.

Figure: Image of a color Doppler echocardiogram.

Preparation

The preparation varies depending on the type of echocardiogram that the cardiologist has prescribed.
The transthoracic echocardiogram does not include any particular preparatory measures: patients can eat and drink even shortly before the examination; if they take medications, they can continue to do so without any problems; etc.
On the contrary, the transesophageal echocardiogram and the exercise echocardiogram require the observance of some specific indications, such as: on the day of the exam, have a complete fast for at least 3-4 hours; only in the case of a transesophageal echocardiogram, notify the doctor of any swallowing problems and do not drive immediately after the examination (better to have a companion); only in the case of an exertional echocardiogram, on the day of the procedure, wear clothing and shoes suitable for physical activity.

Procedure

Procedurally, the transthoracic echocardiogram, the transesophageal echocardiogram, and the exercise echocardiogram have several differences.
Therefore, it is appropriate to treat them individually, on a case-by-case basis.

TRANSSTORACIC ECHOCARDIOGRAM

On the occasion of a transthoracic echocardiogram, an assistant to the cardiologist (usually a nurse) invites the patient to take off the clothes that cover the chest and to sit supine on a special bed in the doctor's office.
Once the patient is lying on the couch, with the chest bare, the cardiologist intervenes. The latter applies, in some strategic points of the chest, a series of electrodes and, in the area where the transducer will rest, a gelatinous substance, known as ultrasound gel.
The ultrasound gel is essential for obtaining good quality images, as it eliminates the air that could be interposed between the transducer and the anatomical area of ​​interest (NB: the air obviously represents a disturbing element in the operation of the transducer) .
Once the gel has been applied, the cardiologist places the transducer on the chest and begins to move it back and forth. As he moves the transducer, he observes what appears on the monitor and records, via the computerized console, the most significant images. Moving the transducer back and forth is important for viewing the heart and associated vessels from different angles.
Depending on the situation, the cardiologist may ask the patient to breathe in a certain way or to turn onto their left side.
Typically, a transthoracic echocardiogram lasts a whole "hour. However, if the current heart condition has some peculiarities, it could last even longer.

TRANSESOPHAGE ECHOCARDIOGRAM

As in the case of a transthoracic echocardiogram, on the occasion of a transesophageal echocardiogram an assistant to the cardiologist invites the patient to remove the clothes that cover the chest and lie down on his back on a comfortable bed.
After that, the situation passes into the hands of the cardiologist, who, first of all, anesthetizes the patient's throat, using a spray or gel specially designed for this purpose.
The application of the anesthetic is fundamental for the next step: the introduction into the esophagus, through the mouth (first) and throat (then), of an endoscope equipped with an ultrasound probe at one "end (clearly the" extremities that the cardiologist will stay near the heart).
The introduction of the endoscope into the digestive system requires great caution. This is why the cardiologist proceeds slowly and with extreme care in carrying out this operation.
If, before the examination, the cardiologist notices that the patient is particularly agitated, he could give him a sedative medicine to help him relax.
Except for difficulties in introducing the endoscope, a transesophageal echocardiogram lasts a total of one hour.

EFFORT ECHOCARDIOGRAM

From the point of view of the instrumentation used, an exercise echocardiogram is, in fact, a transthoracic echocardiogram.
It is important to underline that, for the purpose of a correct evaluation of the patient's cardiac health, this diagnostic procedure involves a double visualization of the heart: one at rest, before physical exercise, and one just after the effort.

AFTER THE PROCEDURE

Generally, after a transthoracic echocardiogram, the patient is free to resume normal daily activities immediately.
On the contrary, immediately after a transesophageal echocardiogram, he must have greater caution, as he is under the effect of anesthetics and sedatives (if administered).

Risks

The risks and side effects of an echocardiogram depend on the type of echocardiogram performed.
In details:

• In the case of a transthoracic echocardiogram, the risks are minimal. The only drawback worth noting consists in the possibility that the removal of the electrodes applied to the patient's chest causes, for the latter, a slight annoying sensation.
• In the case of a transesophageal echocardiogram, the ultrasound probe is likely to irritate the throat as it passes through the throat. The irritation usually lasts a few hours and is bearable. Rarely, it causes serious side effects.
  It is important to emphasize that, throughout the procedure, the cardiologist monitors the patient's vital signs. This is a precautionary measure that allows immediate medical intervention, in case of particular allergic reactions to anesthetics and sedatives (if administered).
• In the case of a stress echocardiogram, there is a risk that exercise and or the drug given as an alternative to exercise could cause some irregular heartbeat.
  Although very rare, this irregularity can have serious repercussions on the patient's cardiac health, even leading to a heart attack.

Results

In most cases, the patient knows the results of his echocardiogram a few days after the procedure. This period of time is used by the cardiologist to accurately analyze the images collected during the ultrasound examination.
It should be noted that there are cardiology studies and hospital centers capable of providing the results of an echocardiogram a few tens of minutes after the diagnostic test.

NEXT STEPS

Based on what emerges from the echocardiogram, the cardiologist decides what the next step will be: if the results on a patient's heart condition are clear, the next step will consist in planning the most suitable therapy (which can be medical and / or surgical ); if, on the other hand, the results show some question marks, the echocardiogram will be followed by further diagnostic tests (CT scan, coronary angiography, etc.).