[AV-block indication: VDD versus DDD].

Single-lead VDD- and dual lead DDD-systems provide a physiologic AV-synchronous stimulation in patients with high degree AV-block. VDD-systems have the advantage to shorten 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. Ventricular lead function is similar in both systems. Comparable results for VDD- and DDD-systems have been shown for the reliability of P-wave sensing with mean values of 99% and above. Thereby nearly complete AV-synchronous stimulation is achievable with both systems. VDD-systems allow no atrial stimulation, which becomes only important if sinus node disease develops. This occurs in approximately one to two percent of patients with high degree AV-block during follow-up. The sinus rate at rest allows an assessment of sinus node function prior to implantation. Another advantage of VDD-systems is their potential to reduce costs. VDD- and DDD-systems provide a similar effective and reliable AV-synchronous stimulation in patients with high degree AV-block. Easier implantation and reduced costs result in an advantage for single-lead VDD-systems.