Atrial fibrillation (VHF) (synonyms: Absolute arrhythmia; Absolute arrhythmia in atrial fibrillation; Absolute bradyarrhythmia; Absolute tachyarrhythmia; Arrhythmia absoluta; Arrhythmia absoluta in atrial fibrillation; Atrial fibrillation; Auricular fibrillation; Bradyarrhythmia absoluta (BAA); Chronic atrial fibrillation; Atrial fibrillation arrhythmia; Intermittent absolute arrhythmia; Intermittent arrhythmia absoluta; Intermittent atrial fibrillation; Paroxysmal atrial fibrillation; TAA [tachyarrhythmia absoluta]; Tachyarrhythmia absoluta; Tachyarrhythmia; Tachyarrhythmia in atrial fibrillation; Vfli; VoFli, VHF, and VHFli; AF or AFib (from English Atrial fibrillation); ICD-10 I48. 1-: Atrial fibrillation) is a transient (paroxysmal or intermittent) or permanent (sustained) cardiac arrhythmia with disordered activity of the atria. VHF is a cardiac arrhythmia that belongs to the group of stimulation disorders. Atrial fibrillation belongs to the supraventricular arrhythmias (arrhythmias that originate in the atria) – in addition to VHF, they include supraventricular tachycardia (SVT) and atrial flutter. Atrial fibrillation is the most common form of supraventricular tachyarrhythmia (SVT) and the most common cause of irregular narrow complex tachycardia (QRS width ≤ 120 ms).On the ECG (electrocardiogram), tachycardic atrial fibrillation exhibits a narrow ventricular complex (QRS width ≤ 120 ms) and is therefore referred to as narrow complex tachycardia. Atrial fibrillation presents otherwise irregular narrow complex tachycardia. Atrial fibrillation is classified according to an internationally accepted standard of the American Heart Association (AHA) and the American College of Cardiology (ACC) as follows:
- First diagnosed/discovered atrial fibrillation (initial diagnosis).
- Paroxysmal atrial fibrillation (duration 1 week or less); current guideline classifies atrial fibrillation episodes of <7 days that are cardioverted as paroxysmal atrial fibrillation
- Persistent atrial fibrillation (duration 1 week to 1 year).
- Long persistent atrial fibrillation (duration longer than 1 year) [in these patients, therapy should be attempted to restore sinus rhythm].
- Permanent atrial fibrillation, i.e. “accepted” atrial fibrillation (= persistent atrial fibrillation should not be treated to maintain rhythm or cardioversion/restoration of normal heart rhythm was unsuccessful)
Depending on the pulse rate, atrial fibrillation is also divided into:
- Bradyarrhythmia absoluta (pulse below 50 beats per minute).
- Normfrequente absolute arrhythmia (pulse 50 to 100 beats per minute).
- Tachyarrhythmia absoluta (TAA; pulse over 100 beats per minute).
Atrial fibrillation can also be divided into valvular atrial fibrillation, which is AF originating from the mitral valve, and nonvalvular atrial fibrillation. Few patients with AF (approximately 10%) have idiopathic AF, referred to as lone atrial fibrillation, i.e., these are patients without structural heart disease and vascular risk factors, and the age of patients is usually less than 65 years. Sex ratio: men are more often affected than women; in old age, women are more often affected than men
Frequency peak: the disease occurs more frequently with increasing age. The prevalence (disease incidence) is 1-2% in those over 40 years of age, 5% in those over 50 years of age, and approximately 10% in patients older than 60 years (in Germany). The incidence (frequency of new cases) is about 80 cases for men and about 60 cases for women per 100,000 inhabitants per year. Course and prognosis: Atrial fibrillation is not life-threatening. Approximately 70% of attacks are not noticed by the affected person. Typical symptoms are fatigue, sudden drop in performance, palpitations (heart palpitations) and insomnia (sleep disturbances). Nevertheless, atrial fibrillation harbors dangers. For example, the risk of apoplexy (stroke) is increased (see below). In one study, the spontaneous conversion rate from atrial fibrillation to sinus rhythm in 48 hours was about 50%; the average duration of AF was 3.9 +/- 5.2 days. Therapy depends on the underlying condition and may include pharmacotherapy (drug treatment) with antiarrhythmics (drugs used to treat arrhythmias) or invasive therapy (e.g., electrical cardioversion; catheter ablation).Furthermore, anticoagulant therapy to prevent thromboembolic complications (apoplexy/stroke) is recommended for all patients with VHF, except for patients with low risk (age less than 65 years or lone atrial fibrillation; see below CHA2DS2-VASc score) or with contraindications (contraindications – see below HAS-Bled score). In one study, patients with AF taking acetylsalicylic acid (ASA) alone were analyzed in terms of apoplexy rate (%/year) depending on the type of AF: paroxysmal AF: 2.1%/year; persistent AF: 3.0%/year; permanent AF: 4.2%/year. Patients with subclinical AF (“without clinical symptoms”) also have an increased risk of apoplexy. For example, one study showed that patients who had subclinical AF in the first three months of the study consequently had a 2.5-fold higher risk of apoplexy than patients without corresponding episodes of AF (incidence rate: 4.2 versus 1.7). It is important to note in this context that the VHF episodes were so far removed in time from the apoplexy that a causal involvement of subclinical VHF in the development of apoplexy is not conceivable. Women are twice as likely to be affected by apoplexy as men (rate ratio 1.99; 95 percent confidence interval: 1.46 to 2.71). In a meta-analysis, the annual rate of apoplexy and systemic embolism was calculated to be 1.50% for paroxysmal AF and 2.17% for nonparoxysmal AF. The unadjusted risk ratio (RR) for thromboembolism in nonparoxysmal AF versus paroxysmal AF was 1.355. In patients not receiving oral anticoagulation, the risk ratio was particularly pronounced at the expense of nonparoxysmal AF (factor of 1.689). Atrial fibrillation leads to a 1.7-fold increase in mortality (number of deaths in a given period, relative to the number of the population in question). The mortality associated with AF is higher in women.Severe course is also more common in woman than in male patients (median National Institutes of Health Stroke Scale (NIHSS) score of 9 vs. 6, p <0.001). Comorbidities (Concomitant Diseases): The Women’s Health Study suggests an association between AF and cancer is likely. Adjusted for age, education, height, BMI, smoking status, physical activity, concomitant and secondary diseases, and participation in screening examinations, the risk of cancer was 48% higher for women with AF than for women without the arrhythmia. The risk was highest shortly after VHF diagnosis, but it persisted beyond the first year. Furthermore, 37% of patients with AF had heart failure.
