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Published on: March 21, 2013
Incidence and prognosis of syncope
Elpidoforos S Soteriades1, Jane C Evans, Martin G Larson
1National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, Mass 01702-5827, USA.
Syncope, or fainting, is common, but cardiac syncope significantly increases death risk. Vasovagal syncope, however, has a generally benign prognosis, highlighting the importance of identifying syncope causes.
Area of Science:
- Cardiology
- Epidemiology
- Neurology
Background:
- The epidemiology and prognosis of syncope in the general population are not well understood.
- Syncope affects a significant portion of the population, necessitating further research into its causes and outcomes.
Purpose of the Study:
- To evaluate the incidence, specific causes, and prognosis of syncope in a large cohort.
- To differentiate the risks associated with various syncope etiologies.
Main Methods:
- Analysis of data from 7814 participants in the Framingham Heart Study (1971-1998).
- Longitudinal follow-up averaging 17 years to assess syncope incidence and outcomes.
- Multivariable-adjusted hazard ratios were calculated to determine risks associated with syncope and its causes.
Main Results:
- Syncope incidence was 6.2 per 1000 person-years, with vasovagal syncope being the most common cause (21.2%).
- Cardiac syncope was associated with significantly increased risks of all-cause mortality (HR 2.01) and cardiovascular events (HR 2.66).
- Syncope of unknown cause also showed an increased risk of all-cause mortality (HR 1.32), while vasovagal syncope had a benign prognosis.
Conclusions:
- Cardiac syncope poses a substantial risk for mortality and cardiovascular events.
- Syncope of unknown cause is linked to an elevated risk of death.
- Vasovagal syncope, including orthostatic and medication-related causes, appears to have a favorable prognosis.
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