Lifetime Prevalence of Transient Loss of Consciousness in an Urban Russian Population.
BACKGROUND
Most international studies on epidemiology of transient loss of consciousness (TLC) were performed many years ago. There are no data about the lifetime prevalence of TLC in Russia.


OBJECTIVE
To identify the lifetime prevalence and presumed mechanisms of TLC in an urban Russian population.


METHODS
1796 individuals (540 males [30.1%] and 1256 females [69.9%]) aged 20 to 69 years (mean age 45.8 ± 11.9 years) were randomly selected and interviewed within the framework of multicentre randomised observational trial.


RESULTS
The overall prevalence of TLC in the studied population was 23.3% (418/1796), with the highest proportion (28%) seen in 40-49 year age group. TLC was significantly more common in women than in men (27.5% vs 13.5%). The mean age of patients at the time of the first event was 16 (11; 23) years, with 333 (85%) individuals experiencing the first episode of TLC under 30 years. The average time after the first episode of TLC was 27 (12; 47) years. The following mechanisms of TLC were determined using the questionnaire: neurally-mediated syncope (56.5%), arrhythmogenic onset of syncope (6.0%), nonsyncopal origin of TLC (1.4%), single episode during lifetime (2.1%). Reasons for TLC remained unidentified in 34% cases. 27 persons (6.5%) reported a family history of sudden death, mainly patients with presumably arrhythmogenic origin (24%).


CONCLUSIONS
Our findings suggest that the overall prevalence of TLC in individuals aged 20-69 years is high. The most common cause of TLC is neurally-mediated syncope. These data about the epidemiology can help to develop cost-effective management approaches to TLC.
Samara Regional Cardiology Dispensary, Samara, Russiam.
S
S
Gudkova
Samara Regional Cardiology Dispensary, Samara, Russiam.
N
N
Cherepanova
Samara State Medical University, Samara, Russiam.
D
D
Duplyakov
Samara Medical Clinical Centre, Togliatti, Russiam.
G
G
Golovina
Samara State Medical University, Samara, Russiam.
S
S
Khokhlunov
Samara State Medical University, Samara, Russiam.
E
E
Surkova
Federal North-West Medical Research Centre, Saint-Petersburg, Russiam.
O
O
Rotar
Federal North-West Medical Research Centre, Saint-Petersburg, Russiam.
A
A
Konradi
Federal North-West Medical Research Centre, Saint-Petersburg, Russiam.
E
E
Shlyakhto
D000328:Adult; D017677:Age Distribution; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000150:complications; D002318:Cardiovascular Diseases / Q000150:complications* / Q000235:genetics; D003645:Death, Sudden / Q000209:etiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012426:Russia / Q000453:epidemiology; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D019462:Syncope, Vasovagal / Q000175:diagnosis; D014474:Unconsciousness / Q000453:epidemiology* / Q000209:etiology*; D014505:Urban Population