Atrial fibrillation

A cardiac arrhythmia is a disturbance of the normal heart rhythm known as sinus rhythm.

Atrial fibrillation (AF) is a type of rapid arrhythmia (tachyarrhythmia) that originates in the atria and results in ineffective and irregular contraction of the heart.

It is the most frequent cardiac arrhythmia and affects the elderly population more frequently. It is also associated with a series of complications (such as embolism or heart failure) that makes the quality of life of patients can be greatly affected. It generates a large number of hospital emergencies.

It can be classified according to its duration in newly diagnosed AF: that which is detected for the first time, paroxysmal: remits in less than 7 days, persistent: lasts more than 7 days and permanent: habitual heart rhythm.

How is it produced?

Under normal conditions, the heart contracts rhythmically and synchronously. This contraction is the result of an electrical impulse that is generated in the atrium, reaches the ventricle and results in a heartbeat. In an arrhythmia there is an alteration of this mechanism that leads to the heart not contracting regularly, generating a rhythm disorder.

In AF, the atrium contracts rapidly and disorganized by multiple electrical impulses, without any coordination, causing also rapid and irregular contraction of the ventricles with ineffective ventricular filling. The irregular rhythm that occurs can reach a rate of 160 to 180 beats per minute (bpm). In the absence of a coordinated atrio-ventricular contraction, the blood can stagnate in the atrium and, as it remains stagnant, give rise to thrombi that can cause embolisms when they leave the bloodstream driven by the heart. Thromboembolism is one of the main complications of AF.

The main causes of AF include heart disease or non-cardiac disease.

The former include: heart valve disease, coronary artery disease, and myocardial (heart muscle) disease.

Among the non-cardiac ones are high blood pressure, anemia, hyperthyroidism, decreased oxygen in the arterial blood, consumption of certain drugs, drugs and alcohol.

Symptoms

Episodes of AF can be symptomatic or asymptomatic. In many cases it is asymptomatic and the symptoms that are detected are those of its complications such as a cerebral embolism or heart failure.

The most common symptoms in AF include: palpitations, chest pain, dizziness and dyspnea or a feeling of shortness and tiredness.

Diagnosis

The basic and most effective diagnostic test to detect this type of arrhythmia is the electrocardiogram, which allows the irregular heart rhythm characteristic of AF to be recorded.

Other complementary tests can be ordered to determine the cause of the arrhythmia, such as:

• Echocardiogram: imaging test that visualizes the morphology and function of the heart.
• Holter: 24-hour recording of the heart rate.
• Cardiac catheterization: a diagnostic test that, through the introduction of a catheter that reaches the heart, through which a contrast medium is injected, allows the vascular tree of the heart to be seen.
• Electrophysiological study: allows to obtain a map of the electrical conduction system of the heart, to find out the type of arrhythmia and its possible origin. Drugs can be given to eliminate the arrhythmia or destroy abnormal conduction pathways using electromagnetic waves.
• blood tests and arterial blood gas to detect possible causes of arrhythmia such as anemia or lack of oxygen.

Treatment

Treatment is aimed at controlling the rhythm and heart rate as well as the appearance of complications associated with this type of arrhythmia (thromboembolism).

• Antiarrhythmic drugs can treat and control most arrhythmias. They are the main treatment option. There are numerous groups of drugs that act by different mechanisms by slowing the heart rate and restoring the normal rhythm of the heart. They can be administered orally or intravenously and always under medical indication and supervision.
• Cardioversion is a treatment used to restore sinus rhythm (normal rhythm) after an electrical shock is applied to the chest or through intravenous drugs. It is usually used in emergency situations when the patient has severe symptoms due to arrhythmia.
• Radiofrequency ablation is a procedure that uses a catheter and device to map the electrical conduction pathways of the heart. Using high-frequency electromagnetic waves, the conduction pathways responsible for the arrhythmia can be destroyed.
• Treatments aimed at reducing the complications of this arrhythmia: anticoagulant drugs.

Prevention

Living a healthy life, avoiding alcohol, tobacco, drugs and stress helps prevent heart disease. Once this arrhythmia is diagnosed, it is important to follow treatment and medical advice to prevent its complications.