[DDD dual chamber pacemakers. Initial experience]

Our preliminary experience with dual-chamber DDD pacemakers is reported. Technological innovations of the device, atrio-ventricular electrode stability and sequential stimulation have contributed to improve the conditions of patients previously submitted to VVI pacemaker implantation. Primary indications for DDD pacemaker implantation in our series included 7 patients with complete atrio-ventricular (A-V) block, 3 with Mobitz type II second-degree A-V block and 2 with sick sinus syndrome. In six of the 12 patients (50%) additional indications included: ventricular tachycardia in 4 patients, atrial fibrillation in one and pacemaker syndrome in one. Other cardiac conditions were diagnosed: dilated cardiomyopathy in 3 patients, ischemic heart disease in 2 patients, valvular heart disease in 2 patients, congenital heart disease in 1 patient and hypertrophic cardiomyopathy in one patient. The implanted pacemakers were: 5 Genesis, 4 Ultra CPI and 3 Versatrax. J-shaped atrial electrodes were used in 8 patients and in 4 instances a screw-in electrode was employed. Improvement of hemodynamic function was achieved by frequent follow up and reprogramming of DDD pacemaker in every patient. While 4 patients died with progressive deterioration of cardiac function, eight patients survived with adequate sequential stimulation. We conclude that DDD pacemakers are reliable and afford symptomatic relief in a broad spectrum of patients.