Vasovagal syncope: an update on the latest pharmacological therapies

Little is known about the epidemiology and prognosis of syncope in the general population. We evaluated the incidence, specific causes, and prognosis of syncope among women and men participating in the Framingham Heart Study from 1971 to 1998. Of 7814 study participants followed for an average of 17 years, 822 reported syncope. The incidence of a first report of syncope was 6.2 per 1000 person-years. The most frequently identified causes were vasovagal (21.2 percent), cardiac (9.5 percent), and orthostatic (9.4 percent); for 36.6 percent the cause was unknown. The multivariable-adjusted hazard ratios among participants with syncope from any cause, as compared with those who did not have syncope, were 1.31 (95 percent confidence interval, 1.14 to 1.51) for death from any cause, 1.27 (95 percent confidence interval, 0.99 to 1.64) for myocardial infarction or death from coronary heart disease, and 1.06 (95 percent confidence interval, 0.77 to 1.45) for fatal or nonfatal stroke. The corresponding hazard ratios among participants with cardiac syncope were 2.01 (95 percent confidence interval, 1.48 to 2.73), 2.66 (95 percent confidence interval, 1.69 to 4.19), and 2.01 (95 percent confidence interval, 1.06 to 3.80). Participants with syncope of unknown cause and those with neurologic syncope had increased risks of death from any cause, with multivariable-adjusted hazard ratios of 1.32 (95 percent confidence interval, 1.09 to 1.60) and 1.54 (95 percent confidence interval, 1.12 to 2.12), respectively. There was no increased risk of cardiovascular morbidity or mortality associated with vasovagal (including orthostatic and medication-related) syncope. Persons with cardiac syncope are at increased risk for death from any cause and cardiovascular events, and persons with syncope of unknown cause are at increased risk for death from any cause. Vasovagal syncope appears to have a benign prognosis. Copyright 2002 Massachusetts Medical Society

There are limited and conflicting data on the lifetime cumulative incidence of syncope in the general population. The aim of our study was to determine the lifetime cumulative incidence and triggers of syncope in the general population. Questions about syncope were added to a cross-sectional survey on cardiovascular risk factors carried out between 2001 and 2003 in 549 native Dutch respondents, aged 35-60 years. The lifetime cumulative incidence of syncope in our study population was 35% (95% confidence interval 31-39%). Syncope occurred more often in women than in men (41% vs 28%; P = 0.003). A peak in the incidence of syncope occurred around the age of 15 years in both men and women. The median number of episodes in persons with syncope was 2 (Inter Quartile Range 1-5). The top five most frequently mentioned triggers of syncope included warm environment, pain, insufficient food intake, seeing blood/venipuncture, and emotion. In conclusion, our study shows that the lifetime cumulative incidence of syncope in the general population is high. Females experience syncope more often than males. The majority of the syncope triggers were related to conditions that affect orthostatic blood pressure regulation and vasomotor responses.