[Carotid sinus syndrome and sick sinus syndrome: 2 frequent and distinct indications for pacemaker implantation].

UNLABELLED

At present, patients affected by carotid sinus syndrome and, more general by speaking, by vasovagal syncopes, are being considered more and more for pacemaker implant. However, neither the real incidence of the carotid sinus syndrome or its relation with the sick sinus syndrome with which it is often associated or even confused is precisely known. Of a total of 298 consecutive pacemaker implants, 36 (12%) were executed for carotid sinus syndrome, 33 (11%) for sick sinus syndrome and 24 (8%) for both. The annual incidence was respectively of 40, 37 and 26 implants per year/million of inhabitants. Patients affected by carotid sinus syndrome, when compared with those affected by sick sinus syndrome, showed: a higher prevalence of syncopes (97 vs 42%) more syncopal episodes per patient (2.9 +/- 2 vs 1.8 +/- 0.9), a lower prevalence of associated cardiac diseases (53 vs 100%), cardiac enlargement (36 vs 88%), heart failure (6 vs 36%) and paroxysmal atrial fibrillation (0 vs 97%), a more frequent indication to VVI pacing (75 vs 3%). Generally, when both syndromes were present, the patients showed intermediate characteristics.

IN CONCLUSION

carotid sinus syndrome is a frequent indication of cardiac pacing as sick sinus syndrome; even if an association is present in about one third of patients, a distinction between carotid sinus syndrome and sick sinus syndrome is justified by theoretical and practical considerations.