Prevention of atrial arrhythmias by pacing

Background: Atrial fibrillation is the most frequent arrhythmia. it can imp air quality of life considerably. Due to thromboembolic complications it co ntributes to the patients' morbidity and mortality and to the costs for the ir medical treatment. Prevention: In chronic atrial fibrillation there is a need for adequate ant icoagulation and heart rate control. In paroxysmal and intermittent atrial fibrillation it should be sought to prevent its progression to chronic atri al fibrillation. Since atrial fibrillation initiates negative processes of remodeling within the atrial myocardium, it has the tendency to perpetuate itself. From a theoretical point of view, it can be expected that all means which prevent episodes of atrial fibrillation or which terminate it immedi ately after its onset, are able to prevent or at least to delay the progres sion to chronic atrial fibrillation. Pharmacologic treatment is usually use d to prevent recurrences of atrial fibrillation. Based on the actual data i t can also be expected that pacemakers with special preventive pacing algor ithms are able to reduce the atrial arrhythmic burden. Besides consequent o verdrive pacing, more sophisticated algorithms like "suppression of prematu re atrial contractions", "post exercise response", "automatic rest rate" or "post mode-switch pacing" have been developed. They can be applied either alone or in combination with special lead positions (interatrial septal pac ing or pacing of the triangle of Koch) or special stimulation configuration s like dual site right atrial pacing or biatrial pacing. These pacing strat egies cover the most relevant onset mechanisms of atrial fibrillation. Furt hermore, there are algorithms to treat atrial tachyarrhythmias actively by antitachycardia pacing (ATP). First clinical results have shown that a bout 2/3 of the diagnosed atrial tachyarrhythmias could be terminated by these means immediately after their onset. Ongoing Trials: This article gives an overview over the principles of pacin g in the management of atrial arrhythmias and ongoing clinical trials in th is field. Before a definite judgement on the clinical relevance of these ne w preventive and therapeutic pacing strategies can be given, the results of these ongoing controlled clinical studies have to be analyzed.