[Carotid sinus hypersensitivity. Median-term development as a function of treatment and symptoms].

The aim of this study was to assess the incidence and natural history of carotid sinus hypersensitivity (CSH) with respect to treatment and symptoms. Between May 1976 and December 1981, 714 patients underwent carotid sinus massage (CSM) during electrophysiological investigation (271 for syncope, 163 for dizziness); 79 had a pathological response (sinus arrest for over 3 s or two successive pauses of over 2 s each). Twenty five of these patients were excluded from the study group; 23 had the sick sinus syndrome or an associated AV block, and two were lost to follow-up. The remaining 54 patients were divided into two groups: Group I, comprising 33 patients who were given no treatment, and Group II, comprising 21 patients who were treated by permanent pacing. The patients in Group I were followed up for an average of 29 +/- 16 months and those in Group II for 25 +/- 22 months. Nine of the 18 patients in Group I, hospitalised for syncope, but none of the 5 patients admitted for dizziness alone, relapsed during follow-up. Only 1 patient without syncope or dizziness at the time of investigation reported having had a syncope during follow-up. The actuarial graph of absence of syncope fell regularly in Group I (58 p. 100 at 5 years), 4 patients in Group I were then given demand pacemakers and there was no further recurrence of syncope (follow-up: 34 +/- 15 months). Only 1 patient, admitted for dizziness, out of the 21 patients in Group II (13 syncopes, 8 cases of dizziness) continued to complain of the symptoms for which he had been paced.(ABSTRACT TRUNCATED AT 250 WORDS)