LONG-TERM FOLLOW-UP OF THE REPRODUCIBILITY OF CAROTID-SINUS HYPERSENSITIVITY IN PATIENTS WITH CAROTID-SINUS SYNDROME

The reproducibility of carotid sinus hypersensitivity to carotid sinus massage was studied in the long-term follow-up of 8 patients with car otid sinus syndrome. A cardioinhibitory response was induced in 7 pati ents, while a vasodepressor response was found in the remaining patien t. The 7 patients were treated with dual-chamber pacemaker implantatio n and the remaining patient was treated with propranolol. All of the p atients remained asymptomatic during a follow-up period of 48+/-11 mon ths. Carotid sinus massage during the follow-up period in patients wit h a cardioinhibitory response revealed asystolic intervals of 3 s or l onger in 4 patients and in 3 patients at the second and third follow-u p examinations, respectively, although there were no significant diffe rences in the ventricular asystolic intervals between before, and 34+/ -11 months and 48+/-11 months after treatment. However, each patient s howed a wide variation in asystolic intervals. The differences in asys tolic intervals between prior to treatment (first) and the third test were significantly greater than those between the first and the second test (2.4+/-1.2 s vs 0.7+/-0.6 s; p<0.05). The one patient with a vas odepressor response had a decreased systolic blood pressure greater th an 50 mmHg by carotid sinus massage at all three occasions. In conclus ion, most patients with carotid sinus syndrome showed abnormal and var iable responses to carotid sinus massage during long-term follow-up pe riod although there was no recurrence of symptoms after treatments. Th e lack of symptoms in these patients was believed to have been due to effective treatment with dual-chamber pacing and beta-blocker, rather than to spontaneous remission.