Atrial fibrillation is the most common arrhythmia in the general population, and its prevalence tends to increase among older people.
Most patients suffering from it are over 65 years old, with more men affected by it than women. The onset of this condition can negatively affect patients’ quality of life.
What Is Atrial Fibrillation?
Atrial fibrillation is a cardiac pathology and occurs when atrial activity is irregular and disorganized, and contractions follow one another at a higher rate than usual (i.e., the heart fibrillates). This abnormality is caused by an electrical defect in the heart that brings the atria into a “short circuit.” The abnormal electrical impulses can reach a frequency of 300 beats per minute and, in most cases, come from heart cells located in the pulmonary veins. This is true in the case of paroxysmal atrial fibrillation.
Generally, the electrical signal originates in the sinoatrial node located in the right atrium. From there, the signal reaches the left atrium, the atria contract, the impulse passes through the atrioventricular node (a kind of dam between the others and the ventricles), and the electrical stimulation then passes to the ventricles. These, in turn, contract and pump blood to the rest of the body.
In patients with atrial fibrillation, the contraction of the upper part of the heart (the atria) is arrhythmic, very fast, and is not synchronized with that of the lower part (the ventricles).
The Three Types of Atrial Fibrillation
From a clinical point of view, three types of atrial fibrillation are distinguished: paroxysmal, persistent, and permanent.
We speak of paroxysmal atrial fibrillation when episodes, which are sporadic and limited to a few hours, occur and resolve within a week. The specialist should treat and monitor this disorder to prevent it from worsening.
The following stage of atrial fibrillation is called persistent: It is a fibrillation that lasts more than 7 days and in which intervention is needed because it does not regress independently.
Lastly, permanent atrial fibrillation is the stage that is considered to be no longer reversible.
Symptoms of Atrial Fibrillation
Patients with atrial fibrillation generally experience a sensation of an irregular, often accelerated heartbeat (arrhythmic heart palp). There may also be shortness of breath (dyspnea) and weakness. The symptoms may be episodic or occur more frequently during physical exertion.
However, in not-so-rare cases, the atrial fibrillation is asymptomatic. These cases are very delicate because the patient does not experience warning signs, the treatment is delayed, and the heart may experience a reduction in its functional capacity, as well as an increased risk of peripheral embolic phenomena.
Atrial fibrillation significantly increases the risk of thrombotic events. The mechanical immobility of the atria can promote the formation of clots that can reach the cerebral circulation and cause cerebral ischemia and stroke.
Atrial Fibrillation: Risk Factors
Certain conditions can favor the onset of this form of arrhythmia, for example:
- High blood pressure;
- Myocardial infarction;
- Heart failure;
- Valvular heart disease;
- Outcomes of cardiac surgery;
- Thyroid or pulmonary diseases.
In addition, some studies have identified a possible correlation between atrial fibrillation and gastroesophageal diseases.
Sleep apnea syndrome is also strongly associated with cardiac arrhythmias, particularly atrial fibrillation.
Tests for Diagnosis
If someone experiences an irregular heartbeat, it is a good idea to consult a specialist cardiologist or arrhythmologist, who will ask the patient to perform a series of tests. The test needed for a diagnosis is the electrocardiogram.
Early diagnosis is critical to safeguard the patient’s cardiovascular health. Uncontrolled atrial fibrillation can lead to heart failure and increase the risk of stroke.
All patients with atrial fibrillation should have a 24h ECG Holter, a test used to assess the “burden” of atrial fibrillation, the total duration of episodes in a day. The Holter can confirm whether atrial fibrillation comes and goes or is always present. This tool can also confirm the presence of atrial extrasystole, which is, in most cases, the one initiating atrial fibrillation. Identifying these extrasystoles is, therefore, of extreme importance.
Another option is the implantation in the subcutis of a microchip, also called a “loop recorder, “ an event recorder. It has a battery that lasts about four years and records all arrhythmic events (as if it were a continuous Holter). It is a small device 3 cm long and 0.5 mm wide and thick.
The most effective method is transcatheter ablation to treat atrial fibrillation and maintain a normal heart rhythm.