Non-invasive characteristics of atrial fibrillation: the value of Holter recordings for the treatment of AF.

Atrial fibrillation (AF) is the most common arrhythmia in man associated with significant morbidity and excess mortality. AF can be 'lone' but is frequently associated with underlying heart disease while in some patients a genetic cause has been identified. In the past decade our knowledge about the mechanisms of AF and our options for (non)pharmacological treatment of AF have increased importantly. Since the success rate of drug therapy is frequently disappointing "hybrid therapy" is often necessary (e.g., drugs in combination with cardioversion, pacemaker implantation or an ablation procedure). Therapy should focus on identifying the specific substrate (underlying heart disease) and triggers for AF in each patient, making a more individualized therapy possible. For this, non-invasive testing becomes more and more important. Holter recordings may show focal activity (monomorphic atrial premature beats, atrial tachycardia) or other supraventricular arrhythmias (AV-nodal reentrant tachycardia, circus movement tachycardia) which can successfully be treated. In addition, AF may transiently convert to atrial flutter (AFL), either spontaneously or after administration of (class IC) drugs. Recent studies have shown that ablation of the flutter circuit or ectopic activity can cure AF in many of these patients.