How does an electrocardiogram work. What information can an ECG provide. How is an ECG performed. What are ECG leads. How do electrical impulses flow throughout the heart. What does an ECG measure.

Understanding the Basics of Electrocardiography

Electrocardiography is a crucial diagnostic tool in cardiology that allows healthcare professionals to analyze the heart’s conduction system. This non-invasive method provides valuable information about the heart’s electrical activity, which is visually represented as an electrocardiogram (ECG). By examining the ECG, medical experts can detect potential cardiac disturbances and assess the overall health of the heart.

What is an Electrocardiogram?

An electrocardiogram, commonly known as an ECG or EKG, is a graphical representation of the heart’s electrical activity over time. It is recorded by placing electrodes on the skin’s surface, typically on the chest, arms, and legs. These electrodes detect the small electrical changes that occur with each heartbeat.

Why is an ECG Important?

ECGs play a vital role in diagnosing and monitoring various heart conditions. They can help identify:

• Abnormal heart rhythms (arrhythmias)
• Heart attacks (myocardial infarctions)
• Structural heart problems
• Electrolyte imbalances
• Effects of certain medications on the heart

The Heart’s Electrical Conduction System

To fully understand an ECG, it’s essential to grasp how the heart’s electrical system functions. The heart’s pumping action is coordinated by a complex network of specialized cells that generate and conduct electrical impulses.

How Do Electrical Impulses Flow Throughout the Heart?

The journey of an electrical impulse through the heart follows a specific path:

1. Sinus Node: The impulse originates in the sinus node, located in the right atrium. This node acts as the heart’s natural pacemaker.
2. Atrial Depolarization: The electrical current spreads through the atria, causing them to contract.
3. AV Node: The impulse then reaches the atrioventricular (AV) node, which acts as a relay station.
4. Bundle of His: From the AV node, the impulse travels through the bundle of His.
5. Bundle Branches: The electrical signal splits into the right and left bundle branches.
6. Purkinje Fibers: Finally, the impulse reaches the Purkinje fibers, causing the ventricles to contract.

What is Depolarization and Repolarization?

During this process, heart cells undergo two main phases:

• Depolarization: When cells lose their internal negativity, causing contraction.
• Repolarization: When cells regain their internal electrical negativity, allowing relaxation.

These phases are crucial for understanding the different components of an ECG tracing.

Components of an ECG Tracing

An ECG tracing consists of several distinct waves and segments, each representing a specific phase of the heart’s electrical activity.

What Do the Different Waves on an ECG Represent?

The main components of an ECG tracing are:

• P Wave: Represents atrial depolarization
• PR Segment: Indicates the transmission of the electrical impulse to the ventricles
• QRS Complex: Depicts ventricular depolarization
• T Wave: Shows ventricular repolarization

Understanding these components allows healthcare professionals to interpret the ECG and identify any abnormalities in the heart’s electrical activity.

ECG Leads: Multiple Perspectives of the Heart

An ECG provides multiple “views” of the heart’s electrical activity through different leads. Each lead offers a unique perspective, allowing for a comprehensive assessment of cardiac function.

What are ECG Leads?

ECG leads are calculated measurements derived from the electrical currents detected by electrodes placed on the skin. A standard 12-lead ECG provides 12 different angles of orientation in relation to the heart.

How Many Types of ECG Leads Are There?

The 12 leads in a standard ECG are divided into two main groups:

1. Six Limb Leads (Vertical/Frontal Plane):
   • Three Standard Leads: I, II, III
   • Three Augmented Leads: aVR, aVL, aVF
2. Six Precordial Leads (Horizontal Plane): V1-V6

Additionally, there are supplementary leads such as V7, V8, V9, and right precordial leads VR1-9, which can provide more detailed information about specific areas of the heart.

Performing an ECG: The Process and Procedure

Conducting an electrocardiogram is a relatively simple and painless procedure that can be performed in various healthcare settings.

How is an ECG Performed?

The process of performing an ECG typically involves the following steps:

1. Patient Preparation: The patient is asked to lie down and remove any metal objects or clothing that might interfere with the test.
2. Electrode Placement: Adhesive electrodes are placed on specific areas of the chest, arms, and legs.
3. Recording: The ECG machine records the electrical activity for a short period, usually about 10-15 seconds.
4. Data Analysis: The recorded information is then analyzed by the machine and/or a healthcare professional.

Can an ECG Be Performed Using Mobile Devices?

Advancements in technology have made it possible to record clinical 12-lead ECGs using just four electrodes and a mobile app on devices like iPads or iPhones. These modern solutions often include automatic interpretation functions, allowing for quick and easy documentation of patients’ symptoms and disease patterns.

Interpreting ECG Results: What Information Can an ECG Provide?

An electrocardiogram provides a wealth of information about the heart’s function and can help diagnose various cardiac conditions.

What Can Be Detected from an ECG?

An ECG can provide information about:

• Heart Rate: The number of times the heart beats per minute
• Heart Rhythm: Whether the heartbeat is regular or irregular
• Conduction Abnormalities: Problems with how electrical signals travel through the heart
• Heart’s Electrical Axis: The overall direction of the heart’s electrical activity
• Chamber Enlargement: Indications of enlarged heart chambers
• Myocardial Ischemia or Infarction: Signs of reduced blood flow or heart attack
• Electrolyte Imbalances: Abnormalities in blood electrolyte levels
• Effects of Medications: How certain drugs are affecting the heart

Advancements in ECG Technology and Future Prospects

The field of electrocardiography continues to evolve, with new technologies and applications emerging to enhance cardiac diagnostics and patient care.

How is ECG Technology Advancing?

Recent advancements in ECG technology include:

• Wearable ECG Devices: Continuous monitoring for extended periods
• Smartphone-Compatible ECG Systems: Allowing for remote monitoring and telemedicine applications
• Artificial Intelligence in ECG Interpretation: Enhancing accuracy and speed of diagnosis
• High-Resolution ECGs: Providing more detailed information about cardiac electrical activity
• Integration with Other Diagnostic Tools: Combining ECG data with imaging and laboratory results for comprehensive cardiac assessment

These advancements are improving the accessibility, accuracy, and versatility of ECG diagnostics, potentially leading to earlier detection and better management of heart conditions.

As our understanding of cardiac electrophysiology deepens and technology continues to advance, the role of electrocardiography in cardiology is likely to expand further. Future developments may include more sophisticated wearable devices, improved AI-assisted diagnostics, and integration with personalized medicine approaches, ultimately leading to better cardiovascular health outcomes for patients worldwide.

Electrocardiogram (ECG) | CardioSecur

Electrocardiography is a method used to analyze the heart’s conduction system, which provides us with information about the heart’s electrical activity. The recording of the conduction system is physically represented as an ECG. This quick and pain-free examination makes it possible to assess the electrical activity of the heart and to detect potential cardiac disturbances.

How do electrical impulses flow throughout the heart?

What are ECG leads?

What information can an ECG provide?

How is an ECG performed?

The heart muscle pumps blood in a specific rhythm throughout the entire body. In order to do this, the heart muscle must contract, which requires an electrical impulse. This electrical impulse comes from the sinus node (located in the right atrium), which acts as the heart’s natural pacemaker. The electrical current is then transmitted via specific pathways throughout the heart, enabling regular contraction and relaxation. This electrical current can be detected on the surface of the body (i.e. the chest wall) via adhesive electrodes.

Pathway of the electrical impulse:

From the sinus node, the electrical impulse starts by spreading throughout the atria (from right to left). When this happens, the cells lose their internal negativity, a process known as depolarization. The depolarization of the atria causes them to contract.

The electrical current then spreads to the atrioventricular node (AV node), from where it is further transmitted to the intraventricular Septum (separates the left and right ventricles). In order to depolarize the ventricles, the electrical impulse travels through the bundle of His, along the right and left bundle branches (from left to right), and ends at the Purkinje fibers. This process causes depolarization of the ventricles, causing them to contract.

While the ventricles are being depolarized, the atria are regaining their internal electrical negativity, a process known as repolarization. This allows them to relax. Once the ventricles have fully depolarized, they too become repolarized, and which point they relax as well.

The picture below shows a simplified version of the conduction system’s pathway.

The heart’s conduction system

You can record a clinical 12-lead ECG using just 4 electrodes and an app on your iPad or iPhone. The automatic interpretation function allows for fast and easy documentation of your patients’ symptoms and disease patterns.

The entire process of depolarization and repolarization is depicted on the ECG. The individual events are represented as spikes and waves, each representing a specific part of the cardiac conduction cycle. This visual representation of the conduction system makes it possible to analyze the heart’s electrical activity.

The picture below shows the pathway of an electrical impulse as it corresponds to the spikes and waves on an ECG. To do this, the heart is shown on its side.

Figure 2: Pathway of an electrical impulse as it corresponds to the spikes & waves on an ECG (Source: Trappe, H-J/Schuster, H-P: EKG-Kurs für Isabel. Stuttgart, 6. Auflage (2013), S. 3 Abb 1.2)

The P wave represents the depolarization (contraction) of the atria, the PR segment the transmission of the electrical impulse to the ventricles, the QRS complex represents depolarization (contraction) of the ventricles and the T wave shows the repolarization (relaxation) of the ventricles. When disturbances of the conduction system are present, this can be detected via abnormalities of the spikes and waves on an ECG.

An electrocardiogram uses electrodes attached to the skin, which are able to detect electrical currents, in order to provide us with information about the heart. The information detected by the electrodes is used to calculate measurements, known as leads. A “lead” is an angle of looking at the heart. A standard ECG includes 12 leads, i.e. 12 different angles of orientation in regards to the heart. Each lead provides us with information about different parts of the heart. A standard ECG typically requires 10 electrodes in order to provide a 12-lead view.

Six Limb leads on the vertical/frontal plane: 3 Standard (I, II, III) and 3 Augmented (aVR, aVL, aVF)

• I: upper left lateral wall
• II, III and aVF: inferior wall
• aVL: upper left lateral wall
• aVR: right lateral wall

Six Precordial leads on the horizontal plane: V₁-V₆

• V_1, V₂: intraventricular septum
• V₃ and V₄: anterior wall
• V₅ and V₆: left lateral wall

Supplementary leads: V₇, V₈, V₉

• left lateral leads V₇, V₈, V₉: The posterior wall in the area of the left ventricle
• right precordial leads VR_1-9

An ECG provides us with information about the heart’s rhythm and rate, problems with the conduction system and/or its electrical axis. Circulation problems of the coronary arteries can also be detected, which can help to diagnose a heart attack.

Various cardiac disorders can be detected via ECG changes:

• Coronary Artery Disease (CAD)
• Atrial Fibrillation or Atrial Flutter
• Ventricular Fibrillation or Ventricular Flutter
• Rapid heart rate (Tachycardia)
• Slow heart rate (Bradycardia)
• Inflammation of the heart muscle (Myocarditis)
• Inflammation of the heart sac (Pericarditis)
• Medication overdose
• Deficit or excess of certain electrolytes

An ECG can be performed as a resting, exercise or long-term ECG.

Resting ECG

During a resting ECG the body must be relaxed (at rest), as the neighboring muscles and nerves also produce electrical tension. The electrodes are attached to predetermined locations on the body, located on the chest, arms and legs, which are connected to the ECG machine via a cable. The electrodes can detect electrical tension of less than a millivolt, which is then transcribed onto graph paper to produce an ECG.

Exercise ECG

An exercise ECG (or stress ECG) is performed under physical stress, as some changes are only detected when the heart is strained. For example, a resting ECG is particularly unremarkable in the setting of Coronary Artery Disease (CAD).

Many heart rhythm disorders or ECG changes can be better detected and diagnosed via an exercise ECG. In addition, an exercise ECG is performed as part of the evaluation of chest pain in certain situations:

• Following a heart attack or cardiac bypass operation
• Stress-induced rhythm disorders
• Evaluation of a rhythm disorder following treatment
• High blood pressure
• Assessment of individual physical capacity

As with a resting ECG, the electrodes are attached to the skin and are connected to the ECG machine via a cable. The patient is placed on either a treadmill or a stationary bicycle. The level of resistance/speed is increased at regular intervals (usually every 2-3 minutes) until the patient can no longer exercise, the maximum heart rate is reached or symptoms and/or ECG changes indicating stress to the heart are present. The ECG reading, heart rate and blood pressure are continuously monitored during the test, and for a few minutes following, in order to observe the return of the heart rate to its baseline.

An exercise ECG should not be performed in the following situations, as it could cause cardiac injury:

• Heart attack within the last 5 days
• Heart muscle inflammation
• Acute lung embolism
• Acute coronary syndrome
• Severely elevated blood pressure
• Certain ventricular arrhythmias
• Severe angina pectoris (chest tightness)
• Narrowing of the aorta

Long-term ECG

An additional way to measure the activity of the heart is a long-term ECG. This measures the heart’s activity over 24 hours and can therefore detect many changes. The electrodes are attached to the skin and connected to a small mobile recording device via a cable. The gathered data is then interpreted by a physician.

A long-term ECG is often used in the following situations:

• Presence of ECG changes under stress
• Extra ventricular beats
• Heart block
• Atrial arrhythmias
• Excessively high or low pulse
• Pauses of the heart beat with loss of consciousness

Long-term ECG’s are typically used to monitor heart rhythm or rate disturbances.

Mobile electrocardiogram with 12 or 22 leads

CardioSecur Pro is the only 22-lead ECG with just 4 electrodes. Among others, it can be used to diagnose anterior, lateral and posterior wall infarctions.

CardioSecur Pro is the only 22-lead ECG with just 4 electrodes. Among others, it can be used to diagnose anterior, lateral and posterior wall infarctions.

Electrocardiogram: Procedure, Risks & Results

An electrocardiogram is a simple, painless test that measures your heart’s electrical activity. It’s also known as an ECG or EKG.

Every heartbeat is triggered by an electrical signal that starts at the top of your heart and travels to the bottom.

Heart problems often affect the heart’s electrical activity. An EKG records a picture of your heart’s electrical activity while you’re being monitored.

Your doctor may recommend an EKG if you’re experiencing symptoms or signs that may suggest a heart problem, including:

• pain in your chest
• trouble breathing
• feeling tired or weak
• pounding, racing, or fluttering of your heart
• a feeling that your heart is beating unevenly
• detection of unusual sounds when your doctor listens to your heart

Measuring the electrical activity of the heart may help your doctor determine if chambers of the heart are possibly too large or overworked. In other cases, an EKG can help determine the cause of your symptoms along with what type of treatment might be necessary.

If you have a family history of heart disease, your doctor may also order an EKG to look for early signs of heart disease. No matter your age, it’s important to be aware of any symptoms that may indicate a heart problem and talk with a doctor about possibly scheduling an EKG.

There are different types of EKG. Some heart problems come and go. In these cases, you may need longer or more specialized monitoring.

Stress test

Some heart problems only appear during exercise. During stress testing, you’ll have a continuous EKG while you’re exercising. Typically, this test is done while you’re on a treadmill or stationary bicycle.

Holter monitor

Also known as an ambulatory ECG or EKG monitor, a Holter monitor records your heart’s activity over 24 to 48 hours or up to 2 weeks while you maintain a diary of your activity to help your doctor identify the cause of your symptoms. Electrodes attached to your chest record information on a portable, battery-operated monitor that you can carry in your pocket, on your belt, or on a shoulder strap.

Event recorder

Symptoms that don’t happen very often may require an event recorder. It’s like a Holter monitor, but it records your heart’s electrical activity just when symptoms occur. Some event recorders activate automatically when they detect arrhythmia. Other event recorders require you to push a button when you feel symptoms. You can send the information directly to your doctor over a phone line.

Loop recorder

A loop recorder is a device that is implanted in your body, under the skin of your chest. It functions as an electrocardiogram would but allows for continuous remote monitoring of your heart’s electrical signals. It’s looking for irregularities that can cause fainting or palpitations.

There are few, if any, risks related to an EKG. Some people may experience a skin rash where electrodes were placed, but this usually goes away without treatment.

People undergoing a stress test may be at risk for a heart attack, but this is related to the exercise, not the EKG.

An EKG only monitors the electrical activity of your heart. It does not emit any electricity and is completely safe, even during pregnancy.

The Holter monitors can sometimes cause an allergy or rash on the areas of the skin where the EKG electrode pads are placed. This is more likely when they’re worn for many consecutive days.

Loop recorders are often used without any negative effects and have gotten smaller and more efficient over time. As with any procedure like this one, there is the possibility of mild pain, slight bruising, or infection at the implantation location.

There are a few things to consider when preparing for an EKG, including:

• removing any metallic objects such as jewelry
• possibly shaving chest hair
• avoiding drinking cold water right before test
• no exercising, or increasing your heart rate, before the test
• keeping the room at a moderate temperature to avoid shivering

Drinking cold water can cause changes in the electrical patterns that the test records, while exercising can increase your heart rate and affect the test results. Removing jewelry and shaving helps attach the electrodes more securely.

Share on PinterestIllustration by Jason Hoffman

An EKG is quick, painless, and harmless. When going through an EKG, here are a few steps to expect during the test:

• After changing into a gown, a technician attaches about 10 soft electrodes (about the size of a quarter) with a gel to your chest, arms, and legs. These electrodes are attached to wires that are attached to the EKG machine.
• If these areas where the electrodes are attached are not shaved, the technician may shave them for you.
• During the test, lie still on the table and breathe normally.
• Do not talk during the test.
• The machine will record your heart’s electrical activity and show results on a graph.
• Once the test is complete, the electrodes are removed and discarded. The entire procedure should take about 10 minutes.

Typically, there is no immediate aftercare following an EKG test or immediate changes to diet or activities unless your doctor recommends otherwise. Results of the test are usually available immediately, and your doctor may go over them with you right away.

In some cases, the doctor may consult a cardiologist to review the results as well.

If your EKG shows normal results, your doctor will likely go over them with you that same day during your visit or at a follow-up visit.

If results appear abnormal, or show signs of any health problems, your doctor should contact you immediately to go over options to improve your heart’s condition. Signs of abnormalities that may show up in an EKG could include:

• irregular heartbeat
• heart defects, including an enlarged heart, a lack of blood flow, or birth defects
• electrolyte problems, chamber dilation, chamber hypertrophy, or how electricity is moving through the heart
• blocked arteries, or coronary artery disease

If the test shows signs of these abnormalities, your doctor will go over options to improve your heart’s condition. This may include prescribing medication or suggesting lifestyle changes such as modifying your diet or exercising more.

Electrocardiography – what is it? – article Mediflex Homeker

Contents

Electrocardiography (ECG) is a method of recording and studying bioelectrical potentials that occur during the work of the heart. ECG does not measure the absolute potential, but the potential difference between two points of the tissue, which makes it possible to judge its metabolic processes. It is thanks to the study of the electrical activity of the heart that the work of the cardiovascular system is evaluated, which makes it possible to identify a number of disorders and pathologies.

Registration of an electrocardiogram involves the installation of electrodes on the body, which fix signals according to standard, enhanced and chest leads. The electrocardiogram is printed on a paper tape or displayed digitally on a computer screen or a special device – an electrocardiograph. Thus, an electrical impulse is taken from the heart muscle at different angles. This allows you to achieve a comprehensive picture of the functioning of each section of the heart tissue and determine the exact place where pathological disorders occur.

Electrocardiography provides information on parameters such as:

• Heart rate;
• Heart rate;
• Location and size of the heart;
• Position of the electrical axis of the heart;
• Condition of the heart.

Indications for electrocardiography

Electrocardiography is an effective non-invasive diagnostic method that is widely used in modern medicine. The need to take an ECG can arise both urgently and planned in hospitals and clinics, at the exits of ambulance teams. The method is in demand during rescue operations and in other emergencies to provide emergency medical care.

ECG is carried out at:

• Any suspicion of pathological processes in the cardiovascular system, as well as their established presence.
• In the presence of symptoms and manifestations such as pain in the chest and thoracic spine, pain in the neck and lower jaw, shortness of breath, swelling of the legs, persistent and severe pain in the upper abdomen, paroxysmal weakness and fainting.
• As a preventive measure for people who are at risk of developing cardiovascular disease. Including an ECG is indicated after reaching the age of 40, with a hereditary predisposition, obesity, atherosclerosis, persistent arterial hypertension, and the presence of bad habits. Removing an electrocardiogram is important when working in hazardous industries and in areas associated with a risk to life, in professions associated with a high level of stress and / or high physical exertion (firefighters, pilots, athletes, rescuers, etc.).
• With hypertension, after infectious diseases, stroke.
• For neurological, endocrine, rheumatological diseases.
• When planning and managing pregnancy.
• To evaluate and control the effects of drugs on the body.
• For testing the function of pacemakers.
• Before hospitalization, in preparation for surgery and other complex medical procedures.

With this method it is possible:

• Detect cardiac arrhythmias (arrhythmia, tachycardia, parasystole).
• Detect violations in the conduction of nerve impulses in the heart.
• Diagnose chronic and acute changes in the heart muscle (myocardial infarction, coronary heart disease).
• Diagnose chronic and acute pathologies of the pulmonary system (pulmonary embolism, chronic bronchitis).
• Detect thinning or thickening (dystrophy or hypertrophy) of the heart muscle.
• Detect electrolyte disorders (magnesium, calcium, potassium, etc.).
• Detect inflammation of the heart muscle (myocarditis), etc.

Among the advantages of electrocardiography, the absence of significant contraindications is primarily distinguished. This diagnostic method is not only accurate, but also safe. However, it is not recommended to conduct an ECG in case of violation of the integrity of the skin in the areas where the electrodes are installed. The method is absolutely safe for children, pregnant and lactating women.

The disadvantage of the method is its short-term information content – the data reflect the work of the heart at a particular point in time, that is, during the study at rest. Therefore, for the most complete assessment, 24-hour Holter monitoring and ECG fixation with exercise (stress tests) are often shown.

ECG interpretation and interpretation in functional diagnostics

Electrocardiogram interpretation is performed by a cardiologist, functional diagnostics specialist or paramedic in an emergency setting.

For interpretation, the received data is compared with a reference ECG sample. On the electrocardiogram, 5 main teeth are distinguished: P, Q, R, S, T and U-wave. A tooth is a convexity or concavity of a line. The characteristics of not only the teeth are evaluated, but also the segments (intervals) between them – PQ, PR, QRST, QRS and ST.

Width, duration, amplitude, shape, frequency, frequency of teeth and intervals, and other characteristics are assumed to be among the main parameters that the medical specialist must evaluate.

Careful examination of the ECG allows you to identify the focus of necrosis and the age of its formation, slowing down the conduction of a nerve impulse through the heart, damage to myocardial cells, and much more.

Comprehensive electrocardiogram evaluation examines the electrical axis of the heart (EOS) to determine the location of the heart in the chest.

Let’s dwell briefly on each of the ECG waves:

• The R wave is the highest, reflects the impulses of the ventricles.
• S-wave shallow, pointing down. Displays the completion of the passage of the impulse in the ventricles.
• T wave showing ventricular repolarization.
• The P wave shows the work of the atria and normally has a height of up to 2.5 mm and a duration of 0.1 sec.
• The Q wave shows impulses in the interventricular septum.

Also an important indicator is sinus heart rate and heart rate, which should normally be within 50-90 beats per minute.

Electrocardiographic methods

An electrocardiogram can be recorded in several ways:

• The classic method involves recording an ECG in 3 standard and 12 leads. Electrodes are placed on the chest and limbs of the patient, while the patient is in the supine position and is at rest.
• 24-hour Holter monitoring involves ECG recording continuously during the day. The patient wears a special device.
• Exercise tests are performed while the patient is on a treadmill or bicycle ergometer, the physical activity is gradually increased.
• Vectorcardiography implies the display of the electrical vector of the heart in the form of a projection of a three-dimensional figure on the plane of leads.
• Precordial mapping involves placing electrodes with a 6×6 matrix on the patient’s chest and processing signals using a computer.
• In intraesophageal electrocardiography, the electrode is inserted into the esophagus.
• Gastrocardiomonitoring includes simultaneous registration of electrocardiogram and gastrogram during the day.
• High-resolution electrocardiography includes fixation of low-amplitude and high-frequency potentials, with an amplitude of 1-10 μV and using multi-bit ADCs (16-24 bits).

Consumables for electrocardiography

For convenient, high-quality and fast electrocardiogram recording, you need not only a special device, but also a number of consumables. Among the most important consumables in this case are:

• Thermal paper. Used for printing and storing electrocardiogram. It comes in rolls and packs and is produced in different formats.
• Electrodes. Bioelectric signals are fixed by contact with the patient’s skin. They can be disposable and reusable, as well as chest and limbs. They are made in the form of suction cups, straps, clothespins, etc.
• Patient cables. Provide data transfer from the electrodes to the device. The number of cable branches depends on the channel of the device.
• ECG batteries. They differ in materials of execution, capacity, voltage. Provide autonomous operation of electrocardiographs.
• Gels. They are applied to the skin to form a contact medium between the skin and the electrodes.
• Napkins and sheets. They are used to remove gel and other contact agents from the patient’s skin, as well as to prepare the couch for the procedure.

The correct selection of consumables, taking into account their compatibility with the electrocardiograph, the objectives and conditions of the study, ultimately ensures the effectiveness of diagnostic measures.

1. Martusevich A.K. Fundamental and clinical aspects of electrocardiography // Vyatskiy Medical Bulletin. 2006. No. 3-4. pp. 68-70.
2. Nesterova E.A. Fundamentals of electrocardiography. Normal electrocardiogram. Module / E.A. Nesterov. – M.: GEOTAR-Media, 2016.
3. Baranov, A.P. Fundamentals of ECG analysis for the clinician / A.P. Baranov, A.V. Strutynsky // Medical business. – 2004. – No. 1. – P. 70–77.

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Electrocardiography | Children’s Medical Center “Miracle Children”

Electrocardiography (ECG) is one of the simplest, fastest and safest diagnostic procedures used to assess the condition of a baby’s heart, whether it is a newborn or an older child. An ECG measures and records changes in the electrical activity of the heart that characterize its performance. ECG data tells doctors the rate and regularity of heartbeats, the size and position of the chambers of the heart, the amount of blood flowing into the heart muscle, and whether there are any abnormalities in its normal functioning. With the help of electrocardiography, it is possible not only to identify already developed acute or chronic diseases, but also to predict their occurrence, which means to start treatment in time and prevent them.

Physical basis of electrocardiographic research.

An electrocardiograph is a galvanometer device for recording the difference in electrical potentials between two areas of the projection of the heart on the surface of the child’s body. In the process of work, the electrical activity of the heart changes constantly and rhythmically. For each stage of contraction or relaxation of the heart muscle of each department, there is its own unique “electrical” handwriting, which is recorded by an electrocardiograph and issued in the form of a characteristic graph – a cardiogram on a strip of paper or a computer screen. The shape and parameters of the characteristic elements of the cardiogram (basic intervals, amplitudes, shapes and sizes of the teeth) carry information for the doctor about the normal or pathological physiology of the heart. The number of waves per minute on the graph shows the heart rate, the distance between the same elements of the cardiogram – the heart rate. ECG waveforms show how the electrical impulses of the heart are formed and how well the individual parts of the heart work together. Characteristic changes in the shape of the size and position of the waves on the cardiogram carry information about any damage to the heart.

Recording of electrical activity from the surface of the body is made through small metal plates (electrodes) that are placed in certain places on the chest, arms and legs of the child. The electrodes are connected to the cardiograph with wires through which information is recorded. An electrocardiograph records the electrical activity of the heart, all parameters that are measured, analyzed and printed out for the doctor.

What diseases can be detected by electrocardiography in children?

Screening (preventive) electrocardiography of the heart, performed in infants aged 4-5 days and 3-4 weeks of life, allows timely detection of electrocardiographic signs (arrhythmias, prolongation of the phase of ventricular contraction), indicating the possible development of sudden death syndrome ( one of the leading causes of infant mortality in the first year of life), and timely start preventive treatment.

1. ECG reveals hypertrophy of the baby’s heart, which can be caused by congenital heart defects, valvular disorders, high blood pressure, insufficient heart contractility, or conduction disorders.
2. Electrocardiography can detect abnormalities in the electrical conduction of the heart tissue, which can cause a child’s heart to beat too fast, too slowly, or at an irregular rate (arrhythmias), causing atrial and ventricular rhythm mismatches.
3. An electrocardiogram will show how well the heart muscle is supplied with blood, and whether there are any disturbances in the blood supply to individual areas, both at rest and during exercise.
4. ECG can be used to judge the functioning of the heart valves and disturbances in blood flow due to their dysfunctions.
5. According to the results of the ECG, it can be concluded that there is an imbalance in the level of electrolyte substances in the child’s blood, which are necessary for the proper functioning of the heart muscle, such as potassium, magnesium and calcium.
6. Electrocardiography can detect signs of inflammatory heart disease (endocarditis, myocarditis, pericarditis).
7. ECG results suggest the presence of cardiomyopathy, an abnormality in the heart muscle itself.

Preparing the child for ECG

Preparing your child for an electrocardiogram does not require restrictions on food and drink: Your child can eat and drink as usual. It is recommended to feed the baby a few minutes before the study to calm him down. For an older baby, you can take his favorite toy with you to the study.

Baby’s skin must be clean: On the day of the test, you must not apply cream, lotion, powder, or baby oil to your child’s skin.

The child’s clothing must allow electrodes to be attached to the child’s chest, wrists and ankles. Babies who are nursing will need to be swaddled as directed by the nurse to keep them still during the exam.

How is an ECG performed?

Total ECG exam time is 5 to 10 minutes, including electrode attachment and detachment. During the examination, your child will lie on a special changing table or couch. Several electrodes (small plastic patches with metal plates) will be attached to your baby’s chest, and one electrode will be attached to each arm and leg. The electrodes will be connected to the electrocardiograph with wires. During the recording of the ECG, the child will not feel anything unpleasant. Electrodes are just highly sensitive sensors that respond to changes in the electrical impulses of the heart. No current will in any case pass or be passed through the body of the child.

It is important that your child lies still during the examination and does not talk during the procedure, for infants it is important that the baby is calm and does not cry. As a parent, you can be there to support and comfort your child during the procedure.

Once the transducer recording is complete, the doctor or nurse will disconnect the wires and remove the electrodes from the skin. After the procedure, the child can lead his normal life without any restrictions. The results of the studies will be analyzed by the electrocardiograph computer, and then by the doctor who performed the diagnosis, your pediatrician or pediatric cardiologist.

The electrocardiogram of infants, due to its peculiarities (in the 1st year of a child’s life, there are 12 different periods of age norms for the ECG), must be analyzed by the doctor who conducted the study.

Special types of electrocardiography

In some cases, special electrocardiographic studies for older children may be prescribed by a pediatrician or pediatric cardiologist.

Bicycle test (stress test): when the cardiogram is taken during a dosed physical activity (pedaling of an exercise bike). This study allows you to see how the child’s heart responds to physical activity.

Holter monitor : Long-term ECG recording of 15-20 minutes may be required for in-depth investigation of arrhythmias. Holter ECG monitoring has been used for a long time to detect hidden disorders of the blood supply to the heart and the rhythm of its work. In this case, electrodes are attached to the child’s skin, and a small computer-cardiograph is hung around the neck or belt, which constantly records the ECG.

Explanation of results

ECG results are available almost immediately. When performing electrocardiography on a traditional apparatus with recording the results on paper or when analyzing the ECG of a baby under the age of 1 year, the doctor will need some time to decipher the results. When using a computer electrocardiograph, a conclusion with calculations of all the main parameters of the cardiogram is issued almost instantly. ECG records in this case are stored as computer files that can be viewed and printed. In the case of analyzing the cardiogram of babies under 1 year old, if deviations from the norm are found in the cardiogram, the help of a cardiologist may be required to decipher and interpret the cardiogram.

In some cases, it may be necessary to repeat an electrocardiographic study or a special type of ECG, accompanied by other types of studies (ultrasound of the heart, vascular Doppler).

Electrocardiographic monitoring of the child’s heart

As your child develops from fetus to newborn, infant to child, adolescent and adult, the growth and development of the body leads to serious permanent changes in the size and position of your child’s heart. The most dramatic of these changes occur at birth and during the first year of life. Unfortunately, not all children undergo such significant changes in the body without complications. Therefore, doctors recommend regular preventive electrocardiographic monitoring of your child’s heart function. Early detection of a pathology or predisposition to it will allow you to choose and carry out the required treatment with maximum efficiency, or make sure that your child is healthy and his body develops without deviations from the norm.