Which are the symptoms?
The symptoms of atrial fibrillation are extremely variable from patient to patient, and can be from very marked to almost absent. The most frequent symptoms, in decreasing order according to the ALFA study, are palpitations (54.1%), dyspnea (44.4%), fatigue (14.3%), syncope (10.4%) and chest pain (10.1%). Palpitations prevail in the paroxysmal form (79%), while dyspnea in the chronic and recent onset (46.8% and 58%, respectively). In addition to symptomatic, atrial fibrillation can also be asymptomatic or silent, representing an occasional finding on standard ECG or dynamic ECG Holter in about 20% of cases.
- chest pain
How is it diagnosed?
The diagnosis of atrial fibrillation itself is very simple, since an electrocardiographic trace, in particular the 12-lead ECG trace, is sufficient. The problem is the difficulty in catching the arrhythmia when it is present (for the short duration or for the total lack of the reference symptoms). Even in follow-up, the main obstacle is the difficulty of detecting with certainty the episodes of atrial fibrillation.
For this we use prolonged electrocardiographic recording systems called dynamic ECG Holter (which can last from 24 hours to several days, generally up to a maximum of 30 days). Then there are small long-lasting recording systems that are inserted subcutaneously through a small incision, called the “implantable loop recorder” (or ILR). These systems can last up to three years and can also be interrogated through remote monitoring, i.e. directly from the patient’s home, without requiring patient access to the hospital. Recently, recording systems of short ECG traces are also available (generally about 30 sec, single channel) based on Smartphone technology, also through the iWatch system, which allow the patient to independently record a short ECG tracing, on which the system performs a first analysis and proposes a first diagnosis of the rhythm. The track can then be sent by email for verification by the Analysis Center: this service is called Cardiotelephone.
In addition to identifying atrial fibrillation with the electrocardiogram, a complete diagnostic framework is necessary to demonstrate or exclude cardiac or endocrine pathologies that cause or facilitate atrial fibrillation and require treatment.
How is it treated?
The treatment of a patient with atrial fibrillation requires knowledge of the aspects of arrhythmia presentation (paroxysmal, persistent, chronic), first event or recurrence, symptomatic or asymptomatic, and the basic clinical situation. Only later can decisions be made about whether or not an attempt should be made to restore the sinus rhythm, how to restore the sinus rhythm, and its subsequent maintenance.
Atrial fibrillation therapy is essentially based on these four aspects:
Check for predisposing conditions (e.g. arterial hypertension, thyroid disorders, gastric disorders, etc)
Prevention of arterial thromboembolism, through anticoagulant drugs
Heart rhythm control, i.e. the attempt to restore sinus rhythm and prevent AF recurrence, particularly in the case of paroxysmal and persistent AF, essentially through antiarrhythmic drugs and transcatheter ablation
Heart rate check (“rate control”), i.e. control of the frequency response, particularly in case of permanent atrial fibrillation, essentially through antiarrhythmic drugs, including beta-blocker drugs and digitalis.
At the first finding of atrial fibrillation, even if asymptomatic, the attempt to restore the sinus rhythm is indicated, providing it’s compatible with the patient’s age and the presence of co-pathologies. If the arrhythmia is of recent onset and in the absence of heart disease, the first therapeutic choice for the restoration of the sinus rhythm is antiarrhythmic drugs. In case of longer duration of the arrhythmia, or of heart disease, or of hemodynamic instability, the first therapeutic choice instead becomes the electrical cardioversion.
Regardless of the technique used for the restoration of the sinus rhythm, great attention must be paid to compliance with the protocols for the prevention of thromboembolic risk, in particular by evaluating the duration of the arrhythmia and any underlying heart disease.
After restoration of the sinus rhythm, in many cases no prophylaxis of recurrence is necessary (e.g. atrial fibrillation from correctable cause, or first episode of short duration and hemodynamically well tolerated). If, on the other hand, based on the clinical picture, prophylaxis is considered appropriate, the first therapeutic step is generally antiarrhythmic drugs, taken as needed or chronically.
In case of drug ineffectiveness or intolerance, or in case of recurrence, catheter ablation procedures may be considered as an alternative to chronic atrial fibrillation.