[Carotid sinus hypersensitivity. Medium and long-term development in patients treated by ventricular pacing].

The problem of pacing patients with carotid sinus hypersensitivity (CSH) is the choice and criteria of selection of the pacing mode. The authors studied 29 patients with CSH treated by VVI pacing over a period of 10 years. The average follow-up was 34 months (range 6 to 96 months). Three of the 27 patients (11%) who were asymptomatic at the outset continued to have symptoms. The nature of the CSH was well-defined in 25 patients; 19 of the 20 cases of cardio-inhibitory CSH and 4 of the 5 cases of mixed CSH were asymptomatic. These two poor clinical results were analysed: the patient with the cardio-inhibitory CSH (one recurrence in 84 months) had a drop of 40 mmHg in systolic blood pressure which fulfilled criteria of the cardio-inhibitory form of CSH (a drop of 30 to 50 mmHg). The second case was a complete therapeutic failure with 3 recurrent syncopal episodes. The patient had a mixed form of CSH (B.P. drop of 65 mmHg) associated with a "pace maker syndrome" (drop of 50 mmHg in systolic blood pressure at the onset of VVI pacing without any sino carotid massage). The authors conclude that the cases of CSH which, during their investigation, are best corrected by dual-chamber pacing or which are associated with a significant pacemaker effect or present retrograde ventriculo-atrial conduction, should receive dual-chamber pacemakers.