Prevalence

Atrial fibrillation occurs in 1% of the population, rising to 4% in people aged 45 years (DH, 2005b), and is as high as 10% in those over the age of 75 years (Lip and Lim, 2007). Atrial fibrillation is not a benign condition. The symptoms alone affect the quality of life of two-thirds of those with the condition (Wyse et al., 2002), but it is perhaps the risk of stroke that makes AF such an important condition. This risk varies, but if AF is left untreated the risk of stroke increases fivefold (Markides and Schilling, 2003), and the risk of all-cause mortality is double that of patients in sinus rhythm (Krahn et al., 1995; Flegel et al., 1987; Kannel et al., 1983).

Assessment

Chapter 8 of the National Service Framework for coronary heart disease (DH, 2005b) stated that people presenting with arrhythmias, in both emergency and elective settings, should receive timely assessment by an appropriate clinician to ensure accurate diagnosis and effective treatment and rehabilitation.

This statement recognises the need for patients with AF to be identified early and treated appropriately. However, the decision-making process is dependent on a number of factors. The cause of AF is a fundamental question that needs to be posed. Many causes of AF, such as alcohol intake and thyrotoxicosis, are reversible. In such cases the successful treatment of the underlying cause can lead to elimination of the arrhythmia. However, AF also occurs in the presence of cardiovascular disease such as mitral valve disease, coronary heart disease and cardiomyopathy. Consequently, a review of a patient with suspected AF needs to include a 12-lead ECG, full medical history to establish the sustainability, tolerability and prior management of the arrhythmia, and additional investigations to identify possible causes of the AF (Box 12.5).

Once a diagnosis of AF is confirmed the practitioner needs to consider both the effects of treatment on underlying medical conditions such as heart failure and the risk of stroke. The latter is achieved using a risk stratification formula such as the CHADS2 score (Gage et al., 2001).

Treatment

Once identified, all patients should receive a hard copy of their ECG documenting their arrhythmia, and a copy should be placed in their records (DH, 2005b).

The goal for the management of AF should be either to attempt to return the patient to a normal sinus rhythm or reduce the heart rate. The former can be achieved either chemically using drugs such as amiodarone, electrically through DC cardioversion or electrophysiologically through surgical or catheter ablation. The latter strategy is adopted to reduce the risks associated with tachycardias, such as heart failure. In this latter approach the patient will continue to experience AF but at a lower ventricular rate. However, it should be noted that all patients with symptomatic AF despite optimal medical therapy should be referred to a heart rhythm specialist (DH 2005b).

The National Institute for Health and Clinical Excellence (2006) provides clinical guidelines for the management of patients with AF. They recommend that patients with paroxysmal AF should be considered primarily for cardioversion. The way in which the restoration of normal rhythm is to be achieved is one for discussion between the practitioner and the patient, taking into account the merits of both chemical and DC cardioversion. However, they suggest that prolonged AF (>48 h) should be treated with electrical cardioversion.

The most complex group are those patients suffering from persistent AF. The NICE guidelines (2006) acknowledge the numerous clinical trials that have explored this phenomenon have not demonstrated a superior strategy. However, the guidelines advise when rate or rhythm control is preferred (Box 12.6). Due to the risk of stroke antithrombotic treatment should be considered regardless of approach.

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