Atrial fibrillation: Cause, diagnosis and treatment

Atrial fibrillation

Atrial fibrillation is a very common arrhythmia in which the heart beats irregularly (2). It is the most common form of abnormal heart rhythm –  six million people, only in Europe and estimation between more than two and a half million and six million in the United States suffer from it (1). Sometimes those affected do not even notice the atrial fibrillation (4). Others experience a “heart stumble” or palpitations (5). The risk of strokes is increased (3). Find out all about the symptoms, diagnosis and treatment of atrial fibrillation.

atrial fibrillation, Atrial fibrillation: Cause, diagnosis and treatment
SOURCE CDC.GOV

ICD codes for this disease are R00, I48, I46, I47, I49, I45, and I44

atrial fibrillation, Atrial fibrillation: Cause, diagnosis and treatment

Description Of Atrial Fibrillation:

Atrial fibrillation is the most common form of cardiac arrhythmia. Mostly older people are affected. Ten per cent of people over the age of 70 suffer from atrial fibrillation.

Normally, an electrical signal is formed in the sinus node in the right atrium, which is transmitted to the heart chambers via a conduction system. There it triggers a muscle contraction and thus the heartbeat. During atrial fibrillation, many circulating electrical excitations are generated in the atria, some of which are conducted to the ventricles via the conduction system. This results in irregular heart rhythm (arrhythmia). It is usually too fast (tachyarrhythmia). If a so-called conduction block is added, it sometimes becomes too slow (bradyarrhythmia).

Atrial fibrillation usually develops over the course of a lifetime. In many cases, it initially occurs in a seizure-like manner (medically: paroxysmal) and then lasts for minutes, hours or even days. At some point, it develops into chronic (permanent) atrial fibrillation, which can persist even under medical treatment.

Due to the circulating electrical signals, the atria do not manage to fill completely with blood. Therefore, the amount of blood ejected by the heart is also reduced. If the heart is already weakened, even less blood is pumped. The blood pressure drops.

 Symptoms Of Atrial fibrillation

Atrial fibrillation is often asymptomatic. Many of those affected feel nothing or only a small performance kink from seizure-like atrial fibrillation. The rest, however, suffer from unpleasant symptoms such as racing heart, dizziness, shortness of breath, chest pain or feelings of anxiety.

The symptoms depend on the speed of the heartbeat. If the heart beats normally fast despite the atrial fibrillation, those affected may only feel tiredness and dizziness. If the heart beats too fast (often more than 100 beats per minute), sufferers usually feel an unpleasant palpitations, often chest pain and shortness of breath. If the heart beats too slowly, they suffer from dizziness or even faint. If the atrial fibrillation becomes chronic, the organism can “get used” to the arrhythmia and the affected person no longer has any pronounced symptoms.

Cause and risk factors For Atrial fibrillation

Atrial fibrillation usually develops at an advanced age. Why it develops, however, is not completely understood. As the structure of the heart changes with age and the heart tissue becomes increasingly scarred, electrical signals are transmitted incorrectly in the atrium. As a result, the signals circulate through the atrial tissue and disturb normal heart activity.

There are several risk factors that can promote atrial fibrillation. Many chronic diseases are among them. Long-standing high blood pressure, heart disease, diabetes mellitus, thyroid and lung diseases, sleep apnoea syndrome or kidney disease can lead to long-term atrial fibrillation. Researchers found that the risk of the appearance of this condition also has a genetic component. Sometimes, however, the arrhythmia develops without a recognisable cause.

Diagnosis and examination

The specialist for this condition is a cardiologist. First of all, the doctor will ask for the patient’s medical history. The following questions are of importance:

  • How often and for how long do you experience palpitations?
  • Do certain factors such as alcohol consumption, sleep deficit or operations trigger the tachycardia?
  • Do you suffer from a heart or thyroid disease?
  • Do you have other complaints during the palpitations?
  • Any history of atrial fibrillation in your family?

This is followed by a physical examination and a pulse and blood pressure check.

Electrocardiogram (ECG)

The most important examination to diagnose atrial fibrillation is the electrocardiogram (ECG). This involves measuring the electrical currents in the heart via electrodes that are attached to the chest. Sometimes an ECG must be written over several days. For this purpose, small ECG devices are available which are hung around the neck. The ECG can also be recorded during physical exercise. Patients have to exercise on a kind of home trainer.

Echocardiography

An ultrasound examination of the heart (echocardiography) can be used to examine its structure and pumping behaviour. Especially if atrial fibrillation has already been diagnosed, it is important to search for blood clots in the heart.

In order to examine the atria more closely and to detect any blood clots that may have formed, the ultrasound probe is inserted into the oesophagus with a tube, as in a gastroscopy. Approximately in the middle of the oesophagus, the right atrium is very close to the ultrasound probe. It can be assessed particularly well from this position. This examination is called transesophageal echocardiography. It is usually performed under a light anaesthetic.

Treatment Of Atrial Fibrillation:

If the atrial fibrillation has developed due to another condition, such as hyperthyroidism, it must first be treated. In many cases, the dysrhythmia then improves on its own.

If the atrial fibrillation has occurred in attacks, it often disappears on its own within a few hours or days. Patients who have already been diagnosed with this condition are usually prescribed medication by their doctor, which they must take as soon as it reoccurs. With this medication, the heart rhythm usually “jumps” back into normal rhythm.

Although the so-called antiarrhythmic drugs are very effective, they often have considerable side effects. When overdosed, the heart sometimes beats so slowly that patients suffer from severe dizziness or fatigue.

If the attacks of tachycardia occur very frequently or are very unpleasant, other drugs can be taken to prevent it from happening in the first place. Dizziness, but also depression, can also occur as side effects.

Since the risk of stroke is increased by very frequent or persistent atrial fibrillation, in many cases medication must be taken to dilute the blood.

Cardioversion

Sometimes this condition is very persistent and does not go away by itself or under medication. The heart rhythm can then also be normalised by external electrical currents. This therapeutic measure is called cardioversion.

Electrocardioversion works similarly to defibrillation during resuscitation. First of all, the patient is connected to various monitoring devices in order to observe the blood pressure and oxygen supply. The patient is then anaesthetised for a short time and current is passed through two electrodes into his heart for a fraction of a second. The current surge often causes the heart to fall back into its normal rhythm. Patients with paroxysmal atrial fibrillation can be treated with electrical cardioversion instead of medication.

Pulmonary vein isolation

Many patients can be cured of this condition by so-called pulmonary vein isolation. In this process, the regions of the heart that trigger atrial fibrillation are obliterated. First, a wire (catheter) is passed through the groin veins into the heart. Since this disease often occurs in the area where the pulmonary veins (pulmonary veins) enter the heart, the tissue is sclerosed there. The chance of recovery with this procedure is 60 to 80 per cent.

Pacemaker implantation

Patients who suffer from a heartbeat that is too slow sometimes have to be treated with pacemaker implantation. The pacemaker ensures a faster and more stable heartbeat.

Protection against stroke

If people suffer from paroxysmal or chronic atrial fibrillation, there is a risk of blood clots forming in the atrium, which can trigger a stroke. Since the blood in the atrium no longer circulates properly due to the dysrhythmia, it can “clump”. The blood clots can pass through the heart into the bloodstream and from there into the cerebral vessels.

If a cerebral vessel is blocked, this is called a stroke. The risk of a stroke can be reduced by taking blood-thinning medication. However, bleeding complications can occur.

A more recent method of protecting against a stroke is to close the so-called atrial ear. The atrial ear is a bulge in the atrium, where the clots are most likely to form.

Prognosis For Atrial Fibrillation

Even after successful therapy, it is always possible that atrial fibrillation will occur again. Relapses are particularly common in people with heart disease.

Paroxysmal atrial fibrillation can develop into permanent atrial fibrillation over time if left untreated. The longer the arrhythmia persists, the more difficult it is to treat. If it is caused by other diseases, for example by hyperthyroidism, the rhythm disturbance often disappears of its own accord after treatment.

The prognosis of this condition is particularly determined by accompanying heart disease. If the heart is already weakened, it can significantly increase mortality. The increased risk of stroke can be easily controlled with anticoagulant medication. The risk of overdose is particularly high in older people because their liver does not work as well, they sometimes have to take other drugs, drink too little or fall down more often. In these cases, one must sometimes advise against taking anticoagulant medication.

You cannot prevent atrial fibrillation itself, but you can prevent the diseases that cause it. A healthy diet, regular exercise and avoiding stimulants will reduce the risk of coronary heart disease – the leading cause of this disease.

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Sandra Eades
Hello I am Sandra Eades, physician, researcher and author from Australia. I am working currently as researcher for a private institution. I have studied in Britain and Australia, where I currently reside. I write about research topics in the organization of the public health government agencies. For the iMS I write about general medical conditions. I also research scholar sources to provide information to writers of other articles. I also check the citations of scholar papers. Finally, I read other articles before they are published. I am also a mother of three children!