[Syncope of unknown origin after electrophysiologic study: is the treatment with pacemaker useful?]

The usefulness of pacemaker treatment appears doubtful in patients suffering from syncope of unknown origin after a complete diagnostic evaluation, which includes electrophysiological study. To better assess the effectiveness of this therapy, 24 patients with syncope of unknown origin and negative electrophysiological study were prospectively and alternatively assigned to treatment with pacemaker (group A) vs treatment without pacemaker (group B). Group A included 12 patients (7 males, 5 females) with a mean age of 64 +/- 10 years. No heart disease was present in 7 cases (58%); 3 cases had chronic ischaemic heart disease (25%) and 2 had hypertensive heart disease (17%). The standard ECG was normal in 7 patients, while various conduction abnormalities were observed in the other 5. The mean number of syncopal episodes was 4.8 +/- 3.9 per patient, and the mean between the onset of symptoms and the beginning of this study was 32 +/- 42 months. In these 12 cases a VVI-M pacemaker was implanted, at a programmed rate of 50 or 60 bpm; in three subjects, the pacemaker was of the diagnostic type ("bradycardia event counter"). Group B included 12 patients (8 females, 4 males) with a mean age of 56 +/- 11 years. Organic heart disease was absent in 7 cases (58%); 4 patients showed hypertensive heart disease (33%) and 1 had mitral prolapse (9%). The ECG was normal in 9 subjects. The mean number of syncopes was 3.2 +/- 1.5 per patient; the mean interval since the onset of symptoms was 18 +/- 19 months.(ABSTRACT TRUNCATED AT 250 WORDS)