[Evolution of pacing modes in patients with implanted pacemakers. Personal considerations on a case load of 171...

In this study retrospectively analyse pacemaker-implantation activity carried out during the last 5 years at the Laboratory of Electrophysiology, affiliated with the Cattedra di Cardiologia of the University of Naples--II Ateneo. Evolution in pacing modes is considered with regard to the patient age, the underlying pathologies and the technical progress in the field. The study has been performed in our laboratory, which is fit up for electrophysiologic studies and implantation of either temporary or permanent pacemakers. Patients included in this study have been implanted in our laboratory either for urgency or for election. They have been retrospectively divided into two groups (age < 65 yrs, 129 patients, and age < 65 yrs, 42 patients); in addition the patients have been classified according to the pathology leading to the implantation: atrio-ventricular block (second degree or third degree), low frequency fibrillation, sick sinus syndrome and carotid sinus syndrome. 171 patients have been examined, of whom 129 > 65 yrs. and 42 < 65 yrs. As for the pacing indication, 54 were atrio-ventricular block (56.1%), 50 were sick sinus syndrome (31.6%), 20 low frequency fibrillation (11.7%), and 1 was carotid sinus syndrome (0.6%). The ratio between single- and dual-chamber pacemakers has been progressively changing: in 1987 we implanted 33 single-chamber and no dual-chamber pacemaker, compared to 7 single- and 23 dual-chamber pacemaker implanted in the last year. This trend is in good agreement with literature data.