What changes can be seen in the ECG with atrial fibrillation?

introduction

Atrial fibrillation is a very common cardiac arrhythmia that is associated with an uncoordinated electrical conduction function in the atria.

The fibrillation describes the often non-functional and clearly too fast contractions (= contraction) of the atria. For this reason, atrial fibrillation is also known as a tachycardiac (too fast) cardiac arrhythmia.

In almost all cases the atrial fibrillation can be shown in the ECG. In particular, the P wave, which comes about through targeted and coordinated conduction in the atria, is changed by atrial fibrillation.

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Can you see atrial fibrillation on the EKG?

Atrial fibrillation is when there is no directional conduction of stimuli in the atria.

Normally the electrical excitation is generated in the sinus node. This sits in the right atrium. From there the excitation is directed to the AV node. AV node stands for atrioventricular node. This lies, as the name suggests, between the atria and the chambers of the heart (ventricles) and conducts the electrical excitation further into the heart chambers.

With atrial fibrillation, this conduction is disturbed in the atrium. Uncoordinated and non-targeted electrical stimulus conduction occurs. Therefore, no P wave can be seen in the ECG. Usually this is replaced by so-called flicker waves, which are differently pronounced in the different EKG leads. The AV node has a watchdog function for the ventricles during stimulus transmission.

If he receives uncoordinated electrical stimuli (as is the case with atrial fibrillation), he does not pass this stimulus on to the ventricles. Instead, the AV node can step in as a second pacemaker and generate its own pulse only for the ventricles. Normally, the resulting heart rate is a little slower, which is reflected in the ECG by a larger distance between the R-waves. It is extremely rare that atrial fibrillation cannot be shown in the ECG.

What does an absolute arrhythmia look like in the EKG?

An absolute arrhythmia (also "Tachyarrhythmia absoluta" called) describes an uncoordinated, clearly too rapid contraction (contraction) of the atria and ventricles. The reason is a disturbed conduction of stimuli in the atria together with a disturbed transfer of electrical excitation into the ventricles. The uncoordinated and disturbed function of the atria is characterized by the fact that there is no directional conduction of stimuli in the atria.

Therefore, no P-wave can be found in the ECG. Usually this is replaced by so-called flicker waves, which can be seen between the individual R-waves (contraction of the heart chambers). The ventricles contract, but they do this very irregularly, which is why the R-waves appear at irregular intervals in the ECG. If the conduction of stimuli in the ventricles functions in a targeted manner, almost normal QRS complexes can be recognized, but they do not appear regularly. Uncoordinated stimulus conduction in the ventricles leads to so-called ventricular fibrillation and is characterized by deformed QRS complexes.

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What does intermittent atrial fibrillation look like?

Intermittent atrial fibrillation is characterized by the fact that it spontaneously reverts to a normal (the so-called sinus rhythm) after its occurrence. This leads to phases in the ECG in which no P waves are recognizable (phase of atrial fibrillation), and this is usually accompanied by an increased pulse rate.

The heart rhythm then "jumps" back into its usual form, which is expressed in the ECG by a P-wave, a QRS-complete and a T-wave. Usually the heart rate is also back in the normal range. Atrial fibrillation may return after a while.

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What does paroxysmal atrial fibrillation look like?

The term "Paroxysmal" comes from the Greek and can best be translated with the term "paroxysmal". In medical parlance it is used synonymously with the term “intermittent”. Therefore, paroxysmal (= intermittent) atrial fibrillation is characterized by a spontaneous change between phases of normal (sinus rhythm) and phases of atrial fibrillation.

During paroxysmal atrial fibrillation, usually no P-wave can be seen in the ECG. The sinus rhythm is usually normofrequent with P-wave, QRS-complex and T-wave.

What does a WPW look like in the EKG?

WPW (Wolff-Parkinson-White Syndrome) is a disease from the spectrum of cardiac arrhythmias. The electrical excitation is usually transmitted more quickly to the chambers via additional conduction paths between the atria and the heart chambers.

This leads to a tachycardia (fast heartbeat) image in the EKG. In addition, the delta wave can be seen in the area of ​​the QRS complex (which represents the contraction of the heart chambers) in the ECG. The QRS complex is thus widened.

Due to pathological (= pathological) feedback of the excitation in the atria, atrial fibrillation can occur with the corresponding signs in the EKG.

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P wave

The P wave in the EKG represents the conduction of excitation in the atria.

The heart's own pacemaker, the sinus node, is located in the right atrium. From there, the electrical stimulus is conducted through the atria towards the ventricles. This process is normally represented by the P-wave.

With atrial fibrillation, the transmission of stimuli in the atria is no longer coordinated. This changes the shape of the P-wave. In most cases there is a completely undirected and chaotic conduction of stimuli in the atria. As a result, only so-called flicker waves or no waves can be recognized at the actual location of the P waves.

When do I need a long-term EKG?

The long-term ECG describes the recording of the electrical currents of the heart over a period of 24 hours. It is generally used to detect possible cardiac arrhythmias.

In the case of persistent atrial fibrillation, a long-term ECG is usually not indicated, as such a cardiac arrhythmia must be monitored in the hospital. In contrast, paroxysmal or intermittent atrial fibrillation is an indication for a long-term EKG. In this form of atrial fibrillation, brief, uncoordinated episodes occur in the conduction system of the atria. However, these disappear again after a short time.

Using a long-term ECG, both the length and frequency of these episodes and thus the severity of the disease can be estimated.

Do I benefit from a tele-ECG / mobile apps?

The Tele-EKG describes the use of a mobile EKG recorder. It is particularly suitable for detecting cardiac arrhythmias at an early stage. Above all, people who suffer from atrial fibrillation benefit from it.

Atrial fibrillation is not always expressed in the form of serious cardiac symptoms and is therefore often not diagnosed immediately. At the beginning of the disease in particular, atrial fibrillation usually only occurs as an attack (intermittent) and disappears again after a short time.

Therefore, it can often not be recognized in normal diagnostics using a simple ECG. This is mainly because atrial fibrillation rarely occurs in exactly the five minutes that the EKG is being written. Atrial fibrillation cannot always be diagnosed with a long-term ECG. Especially if it still occurs very rarely, it does not necessarily have to occur in the 24 hours of the long-term measurement. Even so, even such a rare occurrence of atrial fibrillation can clearly have harmful consequences. Anyone who has already received a diagnosis of atrial fibrillation can benefit from mobile apps. Modern event recorders or pacemakers can communicate with the smartphone via an app and thus trigger an immediate alarm in the event of problems. It is also possible to notify the responsible doctor directly.