[Long-term orthostatic and bicycle ergometry exercise tests in differential diagnosis of syncopal conditions of unclear origin]. / Vozmozgnosti dlitel'noi ortostaticheskoi i veloérgometricheskoi prob pri differentsial'noi diagnostike sinkopal'nykh sostoianii neiasnogo geneza.

AIM: To study efficiency of bicycle exercise test and long-term orthostatic test in differential diagnosis of syncopes. MATERIAL AND METHODS: The study included 113 patients suffering from recurrent syncopes of unclear origin. Twelve healthy volunteers were selected for assessment of the tests specificity. All the patients and controls were examined by means of long-term orthostatic test (LTOT) and bicycle exercise test (BET). RESULTS: Specificity of both tests was 100%. In LTOT syncopes were observed in 52 (46%) cases, including vasovagal syncopes (51 patients), epileptic seizure (1 patient). BET induced vasovagal syncopes in 54 (48%) patients. The results of both tests by inducing syncopes coincided in 30 (26%) cases. In 24 (21%) patients syncopes occurred only in BET while LTOT appeared uninformative. In 21 (18.6%) cases syncopes occurred only in LTOT while BET produced a negative result. 38 (34%) patients had syncopes neither in LTOT nor BET. Both tests induced syncopes in 75 (66%) patients. No complications were observed. CONCLUSION: LTOT and BET are safe and complementary methods in differential diagnosis of syncopes.