[Results of single head VDD-stimulation]

VDD pacing systems provide a physiologic AV synchronous stimulation with only one lead in patients with high degree AV block and normal sinus node function. They compete with DDD systems.    This overview presents actual results of VDD stimulation concerning implantation, atrial sensing and AV synchrony, as well as stability of sinus node function. The results are partly compared with those of DDD systems. Furthermore, ventricular lead performance and cost effectiveness are discussed. New developments towards single-lead DDD stimulation are shown.    VDD systems have the advantage of shortening implantation times by up to 40% and fluoroscopy time is reduced by up to 55%. Additionally there is a non-significant trend towards fewer perioperative complications, as compared to DDD implantation. Comparable results for VDD and DDD systems have been shown for the reliability of P-wave sensing, and thereby AV synchrony, with mean values of 99% and above. Sinus node disease requiring atrial stimulation develops in about 1 to 2% of patients. This renders the missing atrial stimulation in VDD systems as not important. Ventricular lead function is similar in both systems. An advantage of VDD systems is their potential to reduce acute costs and during follow-up.    The results of actual studies demonstrate that VDD systems are established in the therapy of isolated high degree AV block. They are equal to the competing DDD systems and are, in some aspects, superior to them.