Incidence and Prognosis of Syncope

Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
New England Journal of Medicine (Impact Factor: 55.87). 10/2002; 347(12):878-85. DOI: 10.1056/NEJMoa012407
Source: PubMed


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.

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    • "Moreover, the incidence of syncope was shown to increase with age, ranging from 2.6 to 5.4 per 1000 person-years between 20 and 69 years old. The same study shows a sharp rise to 11.1 and 19.5 per 1000 person-years within the 70-79 and above 80 years old populations [2] [3]. "
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    ABSTRACT: Neurally mediated syncope (NMS) patients suffer from sudden loss of consciousness, which is associated with a high rate of falls and hospitalization. NMS negatively impacts a subject's quality of life and is a growing cost issue in our aging society, as its incidence increases with age. In the present paper we present a solution for prediction of NMS, which is based on the analysis of the electrocardiogram (ECG) and photoplethysmogram (PPG) alone. Several parameters extracted from ECG and PPG, associated with reflectory mechanisms underlying NMS in previous publications, were combined in a single algorithm to detect impending syncope. The proposed algorithm was evaluated in a population of 43 subjects. The feature selection, distance metric selection and optimal threshold were performed in a subset of 30 patients, while the remaining data from 13 patients was used to test the final solution. Additionally, a leave-one-out cross validation scheme was also used to evaluate the performance of the proposed algorithm yielding the following results: sensitivity (SE) - 95.2%; specificity (SP) - 95.4%; positive predictive value (PPV) - 90.9%; false positive rate per hour (FPRh) - 0.14 h-1 and prediction time (aPTime) - 116.4s.
    Full-text · Article · Mar 2015 · IEEE Journal of Biomedical and Health Informatics
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    • "The probability of death in both patient groups was based on the Portuguese Population age–specific mortality rate [18]. Following Soteriades et al. [11], this rate was adjusted by a factor of 1.32 to take into consideration the adjusted hazard ratio for the risk of death from any cause in patients with unexplained syncope. We applied a rate of 0.6 syncopes per year among undiagnosed patients in both arms (the value was adjusted to the 3-month cycle length used), based on follow-up data from Farwell [19]. "
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    ABSTRACT: Background To estimate the short- and long-term financial impact of early referral for implantable loop recorder diagnostic (ILR) versus conventional diagnostic pathway (CDP) in the management of unexplained syncope (US) in the Portuguese National Health Service (PNHS). Methods A Markov model was developed to estimate the expected number of hospital admissions due to US and its respective financial impact in patients implanted with ILR versus CDP. The average cost of a syncope episode admission was estimated based on Portuguese cost data and landmark papers. The financial impact of ILR adoption was estimated for a total of 197 patients with US, based on the number of syncope admissions per year in the PNHS. Sensitivity analysis was performed to take into account the effect of uncertainty in the input parameters (hazard ratio of death; number of syncope events per year; probabilities and unit costs of each diagnostic test; probability of trauma and yield of diagnosis) over three-year and lifetime horizons. Results The average cost of a syncope event was estimated to be between 1,760€ and 2,800€. Over a lifetime horizon, the total discounted costs of hospital admissions and syncope diagnosis for the entire cohort were 23% lower amongst patients in the ILR group compared with the CDP group (1,204,621€ for ILR, versus 1,571,332€ for CDP). Conclusion The utilization of ILR leads to an earlier diagnosis and lower number of syncope hospital admissions and investigations, thus allowing significant cost offsets in the Portuguese setting. The result is robust to changes in the input parameter values, and cost savings become more pronounced over time.
    Full-text · Article · May 2014 · BMC Cardiovascular Disorders
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    • "Recurrences may have serious impact on patients' quality of life, being, at times, lifethreatening . Though the pathophysiology of syncope remains undetermined in most cases, abnormal neurally-mediated (vasovagal, NM) reflex is the most largely accepted underlying mechanism, especially in the young [1] [2] [3] [4] [5] [6] [7]. "
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    ABSTRACT: Only scanty data are available in the literature on P-wave (PW) morphology at ECG in patients with history of vasovagal syncope undergoing diagnostic functional testing. In this study, we evaluated resting and head-up tilt testing (HUTT) related changes in PW voltage (PWV) and duration (PVD) and their relationship with triggered syncope. 55 patients, mean aged 41±19y (35 F), without patent heart disease or neuropathy, underwent potentiated HUTT according to the Italian protocol. Heart rate (HR), blood pressure (BP), PR-interval, PWV and PWD were measured at rest, 15min from passive position (15-min) and after nitroglycerine (peak-HR). PW peaking (PWP) was calculated as percent increase in PWV than baseline values. Patients were divided into 2 groups based on tilt-positive (group-A) or negative (group-B) response. 20 patients (36%) entered the group-A, whereas 35 (64%) the group-B. Higher PWV was observed at baseline in group-A (0.147±0.034mV vs 0.114±0.036mV in group-B, p=0.001), with no differences in the remaining ECG measurements. BP was lower in group-A than in B, both at 15-min and peak-HR. HUTT-related PWP in lead II (the most significant among all inferior leads) was 31±30% in group-A vs 95±54% in group-B (p<0.0001) at 15-min, and 52±44% vs 112±72% at peak-HR, respectively (p=0.002). 75% of patients with PWP ≤50% experienced HUTT-triggered syncope, vs 5% of those with PWP ≥100% (p<0.0001). This study shows a potential relationship between HUTT-triggered syncope and low or absent PWP, suggesting a role for atrial chamber functional involvement in the mechanisms underlying the vasovagal syncope.
    Full-text · Article · Apr 2014 · European Journal of Internal Medicine
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