Dual-Chamber Pacing Is Superior to Ventricular Pacing

In the August 1, 1996, issue of Circulation , Connolly et al1 presented their evaluation of current data concerning the use of DDD versus VVI pacing in patients with preserved sinus rhythm. They described a dilemma of DDD/VVI pacing in the following terms: “There are reasons to believe that dual-chamber pacing improves patient tolerance of pacing and reduces morbidity and mortality … However, … this technology is not widely used in most countries.” In summary they noted, “There are theoretical reasons why dual-chamber pacing might reduce mortality … Whether these theoretical expectations and physiological observations are indeed associated with a reduction in major clinical outcomes requires careful and prospective evaluation.”There is some concern that the Connolly article may lead the cardiology community to question what most pacing experts already believe to be the superiority of dual-chamber pacing.There is no question that careful and prospective evaluation may be very useful in confirming the theoretical and physiological observations that many in the pacing community have come to accept as fact. There are several points to be made in support of this argument.Ventricular pacing is the mode most frequently used worldwide.1 This fact certainly cannot be construed as evidence of the superiority or equality of ventricular pacing or of atrial-based pacing (AAI, AAIR, VDD, DDD, DDDR). Most likely this situation reflects the limited selection of pacemakers available in some countries owing to financial constraints, as well as the limited experience of pacemaker implanters with atrial leads and atrial-based pacing. An alternative explanation of why some physicians might be unwilling to adopt a more expensive new technology is that there is a lack of hard evidence from large-scale randomized trials. Certainly, reliable evidence from prospective randomized trials makes it easier to justify more expensive new technology. However, the United …