An ECG (electrocardiogram) measures your heart activity. This is usually done by a specialist and tells them how well your heart is working. In our big ECG test 2021 we want to tell you about different types of ECGs.
These include the resting ECG, the long-term ECG and the stress ECG. Of course, you can also find our product recommendations for mobile ECG devices here. Furthermore, we will answer all your questions about ECGs. For example, how the ECG is measured and what a good report can look like.
- 1 Weekly newsletter with the best personal finance tips
- 2 The most important facts
- 3 The Best ECG: Our Picks
- 4 Guide: Questions you should ask yourself before buying an ECG
- 5 Decision: What types of ECGs are there and which one is right for you?
- 6 Buying criteria: You can compare and evaluate ECGs based on these factors
- 7 Facts worth knowing about the ECG
The most important facts
- ECG devices are used to track the heart rhythm by means of the electrical heart excitation emitted during the heartbeat.
- A basic distinction is made between long-term, resting and stress ECGs. There is a wide range of devices that can be used for this purpose.
- Long-term ECGs provide information about the heartbeat over a longer period of time, for example if heart rhythm disturbances occur irregularly.
The Best ECG: Our Picks
Guide: Questions you should ask yourself before buying an ECG
Before we give you more information about measuring with an ECG device, you can find out who is allowed to carry out such an examination on you and what such an examination looks like. We also show you what a healthy ECG result should look like and where you can best buy your own ECG.
What is an ECG?
This allows conclusions to be drawn about the activity of the heart and any irregularities. As already mentioned, the heart's action is measured by electrodes that are attached to your body, or more precisely to your chest. Each beat of your heart is triggered by an electrical excitation of your heart.
It causes an electric current that the electrodes can pick up and measure. There are different methods of measurement, which are used either on a person who is resting or on a person who is physically exerting themselves. However, you can find out more about this in the "Decision" section.
When is an ECG done?
An ECG is usually performed when certain diseases are suspected. The doctor monitors the heart rhythm, the heart rate and the excitation of your heart. The following diseases cause changes in the function of your heart:
- Heart attack
- Diseases of the blood vessels
- Cardiac arrhythmia
- Inflammation of your heart muscle
- Poisoning from medicines
- Mineral deficiency
In all of these conditions, monitoring heart function is very important and should never be underestimated.
Who is allowed to perform an ECG?
It is not usually necessary for the patient to be admitted to hospital. The examination itself takes only a few minutes and is completely painless.
However, every private person is free to purchase an ECG device and carry out a measurement on their own. However, the preparation of an exact diagnosis and treatment may only be carried out by an appropriate specialist, even though private households are also allowed to purchase an ECG. In the case of concrete suspicions, a doctor should be consulted for the evaluation of the rather complicated recordings.
Which recording systems are available?
In today's linguistic usage, a lead is understood to be the measurement of the ECG. The scientist Einthoven made the beginning, then Goldberger followed and Wilson finally developed a more complex derivation method.
The Einthoven lead is a bipolar limb lead that works according to a traffic light system. In this measurement method, three electrodes plus a grounding electrode are attached to the body according to the traffic light scheme:
The earth electrode is black and is attached to the right leg. Three measurements can now be determined with this:
- Lead I: Between the right arm and the left leg
- Derivation II: Between the right arm and the left leg
- Derivation III: Between the left arm and the left leg
In the Goldberger derivation, as with Einthoven, three electrodes plus a grounding electrode are attached to the body. This is also done by the traffic light system at the same points as with the Einthoven derivation. However, the potentials between two interconnected electrodes and a single electrode are measured.
Conduction according to Wilson
Wilson's conduction is defined by more electrodes than its predecessors. Six electrodes are attached to the body, especially in the chest area. This method should improve on the other two by placing the electrodes closer to the heart and define the results more accurately.
What ECG measurement methods are available today?
The electrodes are placed at precisely specified points on the body and then connected to the ECG device via a colour-coded cable. However, there are different systems that are used depending on the disease or the purpose and duration of the examination.
With a single-lead ECG, the ECG machine is simply held on the skin under the left breast. The device is the only electrode. In a single-lead electrocardiogram, only one lead is displayed.
For this, either two electrodes are attached to the fingers or to the chest. The single-lead ECG is mainly used for long measurements, for example 14 days, but also for quick measurements within a few seconds.
The 3-channel ECG is usually used for one measurement within 24 hours. With this method, three measurements can be taken at the same time. Three electrodes are also attached to the body for this purpose, according to the measurement methods of Einthoven and Goldberger.
With a 12-lead ECG, all three measurement methods are combined. The 12-lead ECG is most commonly used in cardiology for resting and exercise ECGs and has established itself as the standard there.
With this method, basically all your heart activities can be measured. This includes rhythm disturbances as well as other abnormalities.
As the name suggests, a 12-lead ECG can take twelve measurements simultaneously through a total of twelve electrodes. This combines and applies all three lead systems of Einthoven, Golberger and Wilson. The more electrodes are applied to your body, the more leads can be evaluated by the doctor afterwards.
What does a healthy ECG result look like?
Each of these letters stands for a specific segment in the evaluation. In the following, these components are shown both pictorially and actually during the evaluation, as well as briefly explained in key points. Here, too, the general practitioner or, even better, a specialist in cardiology should be consulted for a detailed evaluation in the case of concrete suspicious symptoms.
|P-wave||excitation propagation of the atria|
|PQ-time||conduction from the atria to the ventricles|
|QRS-complex||excitation preparation of the ventricles, here the Q-prong corresponds to the beginning of ventricular excitation|
|ST-segment||Excitation recovery of the ventricles|
|T-wave||Excitation recovery of the atria|
|QT time||Total excitation duration of the ventricles|
|U-wave||Occurs only sometimes, usually without pathological value|
Is an ECG dangerous?
However, depending on the type of ECG you are prescribed, there may be problems with one type of measurement - the stress ECG. These problems are not caused by the device and the measurement itself, but by the physical exertion you are exposed to. If there are problems with the heart, the following symptoms can occur due to the increased exertion:
- Shortness of breath
- Lowering of blood pressure
- Cardiac arrhythmia
- Chest pain
However, you are under medical supervision throughout the treatment and can be treated immediately if necessary. Of course, these symptoms do not have to occur. Your doctor will also discuss with you exactly what to expect before the treatment.
How much does an ECG cost?
Depending on this, devices are used both inexpensively for private use and in higher price segments for everyday practice and hospital use. Simple single-channel ECG devices are available from around €149. These are a good way to get a quick and simple picture of one's own cardiac excitation with the help of a lead.
Mobile ECG devices, which are used by emergency doctors, for example, and can display up to 12 channels of leads, can reach into the higher three- to four-digit range at the other end of the spectrum. ECG devices that are used for everyday hospital and practice work are usually priced even higher. ECG devices are usually not covered by health insurance and must be paid for privately as a self-pay service.
Decision: What types of ECGs are there and which one is right for you?
Basically, there are three different types of electrocardiograms:
- Resting ECG
- Long-term ECG
- Exercise ECG
Each of the above ECG types is used in clinical practice for a wide variety of clinical pictures and symptoms. Depending on the reason why an ECG is recommended by your doctor or why you would like to carry out an electrocardiogram yourself, one of the methods is most suitable. In the following, we would like to introduce you to each of the ECG methods mentioned above and explain the reasons for their use.
What are the characteristics of a resting ECG and what are the advantages and disadvantages?
The resting ECG is to a certain extent the standard method in both the inpatient and outpatient setting. It is routinely performed during almost all inpatient stays and often also during outpatient presentations to the doctor in the practice.
Since a variety of symptoms can be associated with impaired cardiac functionality, an ECG examination is one of the most frequently performed examinations in outpatient and inpatient settings. These symptoms can start with dizziness or balance problems and range from shortness of breath or high blood pressure to chest pain.
In this way, the doctor wants to determine in a differentiated way whether diseases of the heart such as cardiac arrhythmias (e.g. atrial fibrillation) or a heart attack are related to the complaints.
In most cases, a 12-lead ECG is used. This means that a total of 10 electrodes are attached to the extremities and the chest. A total of 12 leads of the heart function can then be seen on the ECG evaluation sheet.
However, 1-channel ECG devices are often used for control or sporadic measurement. These do not have the significance of a 12-lead ECG, but are sufficient for monitoring after a medical examination or for risk patients for the time being. These are particularly suitable for use on the move due to their small size.
What distinguishes a long-term ECG and what are the advantages and disadvantages?
A long-term ECG is often used to record the function of the heart over a longer period of time, usually over 24 hours. This has the advantage that any irregular and infrequently occurring cardiac arrhythmias can be diagnosed. A mobile ECG or tele ECG is often used for this purpose, which can be taken home by the patient and then evaluated by a doctor together with the patient.
If the patient reports irregular dizziness or fainting, for example, and the resting ECG is unremarkable, a long-term ECG is often prescribed. With this method, the patient goes about his or her normal daily life, so that if there are any abnormalities in the subsequent evaluation, conclusions can be drawn about the connection with an activity (e.g. sport).
Particularly in the case of cardiac arrhythmias occurring during sleep, which the patient does not necessarily feel himself, a long-term ECG can be an important diagnostic tool.
Unlike the resting ECG, the long-term ECG usually does not use 10 electrodes (12-lead ECG), but 3 or 5 electrodes on the chest (3/5-lead ECG) because it is easier to handle.
What are the characteristics of a stress ECG and what are the advantages and disadvantages?
An exercise ECG is used because some diseases, such as coronary heart disease, are often not immediately detectable on a resting ECG. For example, cardiac arrhythmias only occur under physical stress.
Furthermore, an exercise ECG is also carried out for sports medicine diagnostics to rule out the possibility of heart problems occurring under sometimes extreme physical exertion.
An exercise ECG is also carried out for follow-up checks after heart operations, heart attacks or in cases of high blood pressure. During an exercise ECG, 10 electrodes are attached to the chest and extremities, similar to the resting ECG. Furthermore, in contrast to the resting ECG or long-term ECG, the blood pressure and heart rate are measured continuously by the doctor present at the same time, as these are important parameters for recording physical performance.
Typically, a bicycle ergometer or a treadmill is used to perform a stress ECG. The load is then gradually increased. Normally, the load is increased at intervals of 25 watts every 2 minutes until the patient is exhausted or the "maximum heart rate" - the rule of thumb for maximum heart rate is: 220 - age is reached.
Buying criteria: You can compare and evaluate ECGs based on these factors
In the following, we will show you which aspects you can use to decide between the many ECGs. The criteria you can use to compare ECGs include:
- Measurement speed
- Battery operation and runtime
- Memory capacity
- USB interface
- Extra functions
In the following, we would like to explain what is meant by the individual criteria and how they are to be classified.
The weight of the item plays a very important role if the device is to be used on the road, for example.
If the device is to be used as a long-term electrocardiogram or for sporadic measurements on the road, it is important that the device is not too heavy.
However, it should be noted that smaller, lighter devices usually have fewer extra functions, such as integrated oxygen saturation, and often only perform a 1-channel measurement. As a result, only one lead is available for evaluation.
For a comprehensive and detailed electrocardiogram, a larger device with the possibility of several chest wall leads is recommended. These should then be examined afterwards by a doctor. The electrocardiogram is also called the heart tension curve in German, and is sometimes also called the heart chart.
Similar to the weight of the electrocardiogram, the size of the device is an important aspect of manageability. The device has to be stored somewhere. Most portable 1-channel and 3/5-channel devices are about the size of an iPhone/iPad and can easily be slipped into a jacket pocket.
Devices that can display 12-lead measurements can be a bit bulkier, as they are usually used at home.
Depending on the model, the measuring speed differs, but most devices only need 30-60 seconds to perform the measurement. The mere measurement is usually done quickly. However, depending on how many electrodes are used and how many leads are output afterwards, the lion's share of the time is probably spent on preparation and subsequent evaluation.
Battery operation and running time
It is important to note that an exclusively battery-powered ECG device will of course also require replacement batteries/charging cables. This is especially true if the device is used outside the home environment.
Especially if the device is to be used on the road and longer measurements are taken, the runtime is very important.
Depending on how long the ECG recording is made and how many channels are used, the runtime differs from device to device. In general, the runtime is longest for devices that only use one channel and for which the recordings are shorter. Most devices with battery operation require "AA" or "AAA" batteries.
The number of batteries depends on the size of the unit and the extra functions offered. As with most other electronic devices, the rule of thumb here is: The more extra functions are offered and used, the greater the power consumption.
A large storage capacity is particularly important for comparability between recordings at different points in time. Here, however, a differentiation must be made between memory recordings. Some devices have an integrated memory, but this is usually smaller than on devices where an additional SD memory card can be inserted.
A distinction can also be made between a long, e.g. 10-hour continuous recording and sporadic short recordings. Both are possible with different devices, so the devil, as so often, is in the detail.
It should also be noted that some manufacturers state the storage capacity in hours and others in the number of measurements that can be recorded with one set of batteries.
A USB interface simplifies transfer to the PC. For evaluation, the ECG findings can later be presented to the doctor or immediately analysed by the doctor himself using software that is usually included in the delivery
The more expensive devices in particular are characterised by extra functions that can be informative depending on the need and, above all, the indication. Here, the recording of heart rate, respiratory rate, oxygen saturation and/or blood pressure should be mentioned in particular, which can be quite relevant if a heart disease is suspected.
In addition, some devices have a "real-time" analysis function that immediately examines the ECG findings for frequent abnormalities. Depending on the device, these analysis functions indicate, for example, irregularities in the heart rhythm/heart rate or in the strength of the amplitudes of the individual segments of the heartbeat.
Facts worth knowing about the ECG
Finally, we would like to answer a few questions about using the ECG device. The main focus here is on the correct evaluation of the findings and what they look like in the case of various diseases of your heart.
When and by whom was the ECG invented?
The ECG device was invented by August Waller in 1882. He immersed his dog's paws in a salt water solution and thus showed the electrical currents of the heart for the first time. Today, these electrical currents are represented in the form of leads.
The ECG measurements are also referred to as leads. The method was further improved at the beginning of the twentieth century by Willem Einthoven, Frank Norman Wilson and Emanuel Goldberger, who added measurements of the extremities and chest wall.
How can I learn to interpret ECG values?
Basically, different textbooks can be used to learn how to interpret the ECG values. However, various YouTube channels can also be used to view and learn about clinical pictures and their ECG images. However, there are also a large number of books available on online shops such as Amazon and Ebay to read up on the subject.
There are even various online courses you can take on the subject. However, these are relatively expensive and still do not replace a doctor's diagnosis. Basically, however, it can be said that the values should best be evaluated by a doctor and that you should not diagnose a disease yourself.
These books and videos will only help you to understand the values a little better and to familiarise yourself with the subject.
Is there a difference between male and female ECG results?
Yes, there is. In everyday clinical practice, ECG diagnostics more often lead to misdiagnoses in women and the findings are less clear than in men. This is usually due to the fact that the accuracy of ECG findings in women is limited by their lower average stress tolerance during stress ECGs and higher multimorbidity.
What do ECG findings in cardiac arrhythmias look like?
Cardiac arrhythmias generally refer to irregularities in the heart rhythm, also called arrhythmias. These include, for example, additional abnormal heartbeats, also called extrasystoles, atrial fibrillation, an excessive (tachycardia) or very slow (bradycardia) heartbeat, ventricular fibrillation or AV block, to name just the most common cardiac arrhythmias.
All these clinical pictures can be identified in the ECG findings. Normally, the heart beats in a regular rhythm. You can monitor your heart rate with a heart rate monitor in addition to the ECG. On the ECG recording, these beats are represented by a curve. Before and after, small elevations show the excitation and relaxation of the heart chambers. In the case of a cardiac arrhythmia, irregularities in the course of the heartbeat can be detected.
In individual areas of the recording, the curves are either shortened, lengthened or flattened. The most common symptoms of cardiac arrhythmia are heart stuttering, dizziness and palpitations in affected patients.
What do ECG findings look like in a heart attack?
In the ECG findings (the chest wall leads), the so-called ST segment of the PQRSTU complex is raised in an acute heart attack. A heart attack can be detected by two signs in the ECG findings:
- Superelevated T-wave
- ST elevation
The ST elevation is an early sign of a heart attack. If a heart attack is suspected, the ECG is evaluated twice within 24 hours in order to exclude or determine an actual heart attack.
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