Long-term follow-up of patients with unexplained syncope and negative electrophysiologic study.
Fifty-eight patients (29 M, 29 F, mean age 60.8 +/- 16 years) with unexplained syncope at the end of a complete clinical and electrophysiological evaluation, were followed for a mean period of 36.6 +/- 20.5 months (median: 30.5 months). Structural heart disease was present in 32 patients (55.2%). The standard ECG was normal in 24 (41.4%) and showed sinus bradycardia (greater than 40 m-1) and/or first degree AV block and/or intraventricular conduction disturbances in 29 patients (50%). During follow-up, recurrences of syncope were observed in 11 of 43 untreated patients (25.6%), three of seven electrically treated patients (42.9%) and two of eight pharmacologically treated patients (25%). The cause of these recurrences was cardiac in one (1.7%), non-cardiac in 10 (17.2%) and remained undetermined in five (8.6%). Sudden death occurred in only one patient (1.7%), who was receiving chronic amiodarone therapy. These results indicate that (1) syncopal recurrences may occur in an appreciable percentage of patients with unexplained syncope and a negative electrophysiologic study during a relatively long-term follow-up, (2) syncopal recurrences, when they occur, are generally due to a non-cardiac cause, (3) sudden death is an occasional and rare event in this patient population and (4) empirical prophylactic treatment with a permanent pacemaker or antiarrhythmic drugs does not usually prevent complications during the follow-up.
Raviele
A
A
Division of Cardiology, Hospital of Mestre, Venice, Italy.
Proclemer
A
A
Gasparini
G
G
Di Pede
F
F
Delise
P
P
Piccolo
E
E
Feruglio
G A
GA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003645:Death, Sudden / Q000209:etiology; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013575:Syncope / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology