VVIR or DDD(R): Does it matter?

A continuing emphasis on cost effectiveness in health care may require that we use more expensive pacing systems only in situations where there is clear medical and scientific evidence of increased efficacy. Although dual-chamber and/or sensor-based, rate-modulating pacing systems are electronically no less reliable, they are part of a more complex pacing system. The requirement for two leads, one of which must maintain both pacing and sensing in the atrium, will inevitably impact the cost and reliability of such systems compared with a single-chamber ventricular system. Yet, there is clear evidence that AV synchrony is important at rest, particularly in patients susceptible to pacemaker syndrome, and there is mounting evidence that AV synchrony during exercise is beneficial independent of rate response. Finally, and perhaps most important, there is the suggestion that patient longevity may be extended by using pacing systems that preserve AV synchrony and/or minimize ventricular pacing.