In a joint consensus statement, the Heart Rhythm Society (HRS) and the American College of Cardiology Foundation (ACCF) have issued recommendations, in collaboration with the Society of Thoracic Surgeons, on the use of single- vs. dual-chamber devices for patients who are eligible (according to existing guidelines) for pacemaker implantation.
In the consensus statement (which has been simultaneously published in Heart Rhythm and the Journal of the American College of Cardiology), HRS president Anne Gillis, University of Calgary, Libin Cardiovascular Institute of Alberta, Canada, and others reported that although a previous consensus statement (the 2008 ACCF/American Heart Association/HRS guidelines on device therapy for cardiac rhythm abnormalities) reviewed pacemaker mode selection, it did not provide specific recommendations for choosing between single- or dual-chamber devices. Gillis et al wrote: “The purpose of this 2012 consensus statement is to provide a state-of-the-art review of the field and to report the recommendations of a consensus writing group, convened by HRS and ACCF, on pacemaker device and mode selection.” They added that they divided patients into three subgroups: those with sinus node dysfunction (SND), those with atrioventricular (AV) conduction block, and patients with other less common indications for pacing (eg, neurocardiogenic syncope).
According to Gillis et al, two important developments in the natural history of SND are atrial fibrillation and AV conduction block. They stated that the risk of developing atrial fibrillation is significantly influenced by the mode of pacing, writing that a meta-analysis of clinical trials showed: “A highly significant 20% relative risk reduction in atrial fibrillation with atrial or dual chamber pacing compared to ventricular pacing.” Thus, a class I (level of evidence A) recommendation is given to dual-chamber pacing or single-chamber atrial pacing for patients with SND and intact AV conduction. Additionally for patients with SND, dual-chamber pacing, over single-chamber atrial pacing, is given a class I recommendation (level of evidence B).
However the benefits of dual-chamber pacing above other forms of pacing for patients with AV block is less clear-for example, Gillis et al reported, one study showed there was no significant differences in the annual rate of developing atrial fibrillation in patients with only AV conduction system disease between those who have received a dual-chamber pacemaker and those who had received a ventricular single-chamber pacemaker. The consensus statement authors, therefore, give a class I recommendation for dual-chamber pacing for patients with AV block (level of evidence C) but also give class I recommendation to single-chamber ventricular pacing (level of evidence B) as “an acceptable alternative to dual-chamber pacing in patients with AV block that have specific clinical situations that limit the benefits of dual-chamber pacing [eg, those with significant medical comorbidities].”
Other recommendations in the consensus statement are that dual-chamber or atrial pacing, compared with ventricular pacing, is recommendation for symptomatic or high-risk patients with congenital long QT syndrome (class I, level of evidence C) and that single-chamber atrial pacing is not recommendation for patients with neurocardiogenic syncope (class III, level of evidence C).
Gillis said in a press statement: “As new clinical data emerges and technology advances, it is important that clinicians and researchers collaborate to update our knowledge and ensure the best quality of care is delivered. This document represents the first recommendations specific to pacing devices and mode selection for the individual patient and provides a framework for clinicians and healthcare administrators to select the best possible therapy to optimise patient outcomes.”