Atrial fibrillation: symptoms to watch out for
Atrial fibrillation is the most common arrhythmia in the general population and its prevalence tends to increase with age
The majority of patients suffering from it are over 65 years old, with a greater involvement of men than women.
The onset of this disease can have a very negative impact on patients’ quality of life.
What is atrial fibrillation?
This arrhythmia is a cardiac pathology and occurs when atrial activity is irregular and disorganised, and contractions occur at a higher rate than normal (the heart fibrillates).
Underlying this abnormality is an electrical defect in the heart that causes the atria to ‘short-circuit’.
The abnormal electrical impulses can reach a frequency of up to 300 beats per minute and in the vast majority of cases originate from heart cells located in the pulmonary veins.
This is very true in the case of paroxysmal atrial fibrillation.
In normality, the electrical signal originates in the sinoatrial node located in the right atrium: from here, the signal reaches the left atrium, the atria contract, the impulse passes through the atrioventricular node (a sort of dam between the atria and the ventricles) and the electrical impulse then passes to the ventricles.
These in turn contract and pump blood to the rest of the body.
What happens in patients with atrial fibrillation is that the contraction of the upper part of the heart (the atria) is arrhythmic, very fast, and is not synchronised 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 can be distinguished: paroxysmal, persistent and permanent.
We speak of paroxysmal atrial fibrillation when episodes, sporadic and lasting only a few hours, occur and resolve within a week.
This disorder must be treated and monitored by a specialist to prevent it from worsening.
In fact, persistent is defined as the next stage of atrial fibrillation: a fibrillation that lasts more than 7 days and in which an intervention is necessary to interrupt it because it does not regress independently.
Finally, permanent atrial fibrillation is the form that is judged to be no longer reversible.
The symptoms of atrial fibrillation
Patients with atrial fibrillation generally experience a sensation of an irregular, often accelerated heartbeat (arrhythmic heartbeat); they may also experience shortness of breath (dyspnoea) and a feeling of weakness.
Symptoms may be episodic or occur more frequently during physical exertion. However, in some cases, which are not so rare, atrial fibrillation is asymptomatic.
These cases are very delicate because the patient does not feel any warning signals, any treatment is delayed and the heart may suffer a reduction in its functional capacity, as well as increasing the risk of peripheral embolic phenomena.
In fact, atrial fibrillation significantly increases the risk of thrombotic events: the mechanical immobility of the atria can favour the formation of clots that can reach the cerebral circulation and cause cerebral ischaemia and strokes.
Atrial fibrillation: risk factors
Certain conditions can favour the onset of this form of arrhythmia, examples of which are:
- arterial hypertension;
- myocardial infarction;
- heart failure;
- valvular pathologies;
- outcomes of cardiac surgery;
- thyroid or pulmonary pathologies.
Furthermore, some studies have identified a possible correlation between atrial fibrillation and gastroesophageal pathologies.
Sleep apnoea syndrome also has a strong association with cardiac arrhythmias, particularly with fibrillation.
Tests for diagnosis
In the presence of an irregular heartbeat, it is a good idea to consult a cardiologist or arrhythmologist, who will invite the patient to perform a series of tests.
The test of choice for diagnosis is the electrocardiogram.
An early diagnosis is essential to safeguard the patient’s cardiovascular health.
Uncontrolled fibrillation can lead to heart failure and increase the risk of stroke.
All patients with fibrillation should have a 24-hour ECG holter, a test used to assess the ‘burden’ of atrial fibrillation, i.e. the total duration of episodes in a day.
The holter can confirm whether atrial fibrillation comes and goes or is always present.
This instrument can also confirm the presence of atrial extrasystole, which is in most cases the one that initiates fibrillation: identifying these extrasystoles is therefore of fundamental importance.
Another instrument that can be evaluated is the implantation in the subcutaneous tissue of a microchip also known as a ‘loop recorder’ or event recorder.
It has a battery that lasts about 4 years and serves to record 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 of maintaining normal heart rhythm is transcatheter ablation for the treatment of fibrillation.