Physiological Dual Chamber Pacemaker Implantation (VDD Type, a Report of 2 Cases)

The implantation of pacemaker will be necessary in not only complete heart block after cardiac operation, but also sick sinus syndrome and a variable conduction disturbancs. We had had so many experiences of single chamger pacemaker(VOO, VVI etc) implantation in patients with complete heart block. But single chamber ventricular pacemaker had some problems because only ventricular pacemaker could not use normal sinus rhythm. Recently, we have tried to use the ventricular pacing system to a dual chamger pacing system in the patient with heart block. So many papers pointed that the decrease in cardiac out put of 15 to 25% with VVI pacing as compared with the normal sinus rhythm. We have experienced one 10 years old boy who had a single atrium had developed complete heart block after patch repair of atrial septal defect, and another 49 years old male patient who was suffered from frequent syncope with bradycardia. The first boy was taken VDD dual chamber pacemaker implantation through left subclavian vein puncture method on 14 days after open heart surgery because he had normal regular P-wave. And the second male patient was taken DDD typed dual chamger pacemaker implantation through left subclavian vein puncture and the DDD typed pacemaker was transformed to VDD pacemaker, also because he had normal regular P wave,too. Their postoperative couse was in uneventful and were discharged without complication. Their conduction have been in good to now.