[Syncope: many studies and few diagnoses?]

Syncope is a frequent disorder shows diagnostic difficulties, so that an important percentage of patients remain without diagnosis after the implementation of diagnostic tests that sometimes are unnecessary.

A retrospective analysis of the patients admitted during a period of two years because of syncope in an Internal Medicine Service was carried out.

Of a total of 2,878 patients hospitalized during the years 1999 and 2000, 79 were admitted because of syncope (2.74%). Forty-five (57%) were men and 34 (43%) were women, with a median age of 68.8 years. Twenty-seven patients (34%) had history of syncope. After a median hospitalization of 9.5 days, the etiological diagnosis was established in 53 (67%) patients: in 25 patients (31.6%) the syncope was mediated by neurological mechanisms, in 16 (20.25%) it was of cardiology origin, in 4 (5.06%) it was of neurological origin and in 8 (10.1%) the syncope was secondary to other causes. In 54 patient (68.8%) at least one cardiology test was carried out (41 Holter, 32 echocardiograms, 6 tilt board tests, 3 maneuvers of massage of the carotid sinus, 3 ergometry studies, 3 electrophysiological studies, 2 coronary angiographies and 3 ventilation perfusion lung gammagraphies). In 51 patient (64%) at least one neurological test was carried out (31 EEG, 42 CT, 2 MNR, 1 Doppler cranial ultrasound and 3 electroneuromyogram). Only 4 of the Holter carried out were diagnostic, as well as 3 of the echocardiograms and only 2 of the CT carried out. No EEG was useful for the etiological diagnosis of the syncope.

There is an excessive utilization of some diagnostic tests (EEG, Holter, cerebral CT), in spite of which in an important percentage of patients with syncope the etiological diagnosis is no done (33%). The use of diagnostic algorithms based on detailed clinical history, physical exploration and assessment of the ECG is proposed, that they would make it possible to issue a diagnostic hypothesis from which there could be begun the diagnostic study with a use as rational as possible of the complementary examinations.