Classifying syncope

A framework to simplify paediatric syncope diagnosis

This paper aims to improve the diagnosis of syncope and transient loss of consciousness (TLOC) in children. Diagnostic problems stem, first, from some causes spanning various disciplines, e.g. cardiology, neurology and psychiatry, while the most common cause, vasovagal syncope, is not embraced by any specialty. Second, clinical variability is huge with overlapping signs and symptoms. Third, the approach to TLOC/syncope of the European Society of Cardiology (ESC) is underused in childcare. We explain the ESC guidelines using an additional paediatric literature review. Classification of TLOC and syncope is hierarchic and based on history taking. Loss of consciousness (LOC) is defined using three features: abnormal motor control including falling, reduced responsiveness and amnesia. Adding a < 5 min duration and spontaneous recovery defines TLOC. TLOC simplifies diagnosis by excluding long LOC (e.g. some trauma, intoxications and hypoglycaemia) and focussing on syncope, tonic-clonic seizures and functional TLOC. Syncope, i.e. TLOC due to cerebral hypoperfusion, is divided into reflex syncope (mostly vasovagal), orthostatic hypotension (mostly initial orthostatic hypotension in adolescents) and cardiac syncope (arrhythmias and structural cardiac disorders). The initial investigation comprises history taking, physical examination and ECG; the value of orthostatic blood pressure measurement is unproven in children but probably low. When this fails to yield a diagnosis, cardiac risk factors are assessed; important clues are supine syncope, syncope during exercise, early death in relatives and ECG abnormalities.  Conclusions: In adults, the application of the ESC guidelines reduced the number of absent diagnoses and costs; we hope this also holds for children. What is Known: • Syncope and its mimics are very common in childhood, as they are at other ages. • Syncope and its mimics provide considerable diagnostic challenges. What is New: • Application of the hierarchic framework of transient loss of consciousness (TLOC) simplifies diagnosis. • The framework stresses history-taking to diagnose common conditions while keeping an eye on cardiac danger signs.

Decision-Making in Patients with Vasovagal Syncope: A Preliminary Study

The aim of this study was to evaluate the differences in performance during a decisional conflict task between subjects with emotional/blood phobia and those with an orthostatic vasovagal syncope. A total of 332 young subjects were included, from which 99 were excluded because of their condition or treatment. The subjects were classified into four groups depending on their responses to a questionnaire: 98 in a control group, 10 in an emotional/blood phobia syncope group, 38 in an orthostatic syncope group, and 87 in an unclear status group. This former group was excluded. The subjects performed a decisional conflict task to quantify their conflict-management ability. The task was the computer version of the Simon Task. Emotional/blood phobia syncope subjects showed a delayed reaction time when faced with decisional conflict in comparison with the control and orthostatic syncope subjects (55.8 ± 17.7 ms, 20.5 ± 4.9 ms, and 13.4 ± 9.2 ms, respectively, p ≤ 0.05). Our result suggests that emotional/blood phobia and orthostatic syncope are two clinical entities. Decisions could be a target of management in patients with emotional/blood phobia syncope. The altered decision-making of subjects with emotion/blood phobia syncope emphasized the role of higher cerebral functions in blood pressure control.

New hemodynamic criteria to separate classical orthostatic hypotension from vasovagal syncope

OBJECTIVE

To define and evaluate hemodynamic criteria to distinguish between classical orthostatic hypotension (cOH) and vasovagal syncope (VVS) in tilt table testing (TTT).

METHODS

Inclusion criteria for VVS were a history of VVS and tilt-induced syncope defined as a blood pressure (BP) decrease and electroencephalographic changes during syncope with complaint recognition. Criteria for cOH were a history of cOH and a BP decrease meeting published criteria. Clinical diagnoses were established prior to TTT. We assessed (1) whether the decrease of systolic BP accelerated, "convex," or decelerated, "concave"; (2) the time from head-up tilt to when BP reached one-half its maximal decrease; (3) the difference between baseline heart rate (HR) and HR at BP nadir. We calculated the diagnostic yield of optimized thresholds of these features and their combinations.

RESULTS

We included 82 VVS cases (40% men, median age 44 years) and 65 cOH cases (66% men, median age 70 years). BP decrease was concave in cOH in 79% and convex in VVS in 94% (p < 0.001). The time to reach half the BP decrease was shorter in cOH (median 34 sec, interquartile range (IQR) 19-98 sec) than in VVS (median 1571 sec, IQR 1381-1775 sec, p < 0.001). Mean HR increased by 11 ± 11 bpm in cOH and decreased by 20 ± 19 bpm in VVS (p < 0.001). When all three features pointed to VVS, sensitivity for VVS was 82% and specificity was 100%. When all three pointed to cOH, sensitivity for cOH was 71% and specificity was 100%.

INTERPRETATION

These new hemodynamic criteria reliably differentiate cOH from VVS.

Syncopal attacks in children: Is it cardiac or epilepsy related?

BACKGROUND

Transient loss of consciousness (TLOC) may be mistaken for other disorders like epilepsy. Our objectives were to identify symptoms that could help differentiate epilepsy from syncope among children with TLOC and to validate previously suggested criteria.

METHODS

We retrospectively reviewed the charts of patients aged 18 years or younger who presented with TLOC attacks from January 2008 to December 2018 at King Saud University Medical City, Riyadh, Saudi Arabia. Symptoms from which epilepsy and syncope could be predicted with high accuracy were included in the previously suggested criteria. The discriminative abilities of current and previous criteria were examined in receiver-operating characteristic analyses.

RESULTS

Data from 46 patients, 32 with confirmed epilepsy and 14 with syncope, were included in this analysis. The mean age was 12.1 years (S.D., 4.3 years), and 60.9% of the patients were girls. According to our proposed criteria, the sensitivity, specificity, and accuracy of symptoms in predicting epilepsy were 68.8%, 85.7%, and 73.9%, respectively, and the area under the curve was 0.814 (confidence interval 0.686 to 0.941, P = 0.001). According to previously suggested criteria, the sensitivity, specificity, and accuracy of symptoms in predicting epilepsy were 63.2%, 62.5%, and 63.0%, respectively, and the area under the curve was 0.730 (confidence interval 0.541 to 0.92, P = 0.063).

CONCLUSIONS

A number of self-reported/observed symptoms can be used to distinguish epilepsy from syncope with high discriminative ability. The current findings still need to be validated in larger, preferably multiple populations before they can be safely relied upon.

Evaluation of Syncope in Older Adults

The older adult patient with syncope is one of the most challenging evaluations for the emergency physician. It requires clinical skill, patience, and knowledge of specific older adult issues. It demands care in the identification of necessary resources, such as medication review, and potential linkage with several multidisciplinary follow-up services. Excellent syncope care likely requires reaching out to ensure institutional resources are aligned with emergency department patient needs, thus asking emergency physicians to stretch their administrative talents. This is likely best done as preset protocols prior to individual patient encounters. Emergency physicians evaluate elders with syncope every day and should rise to the challenge to do it well.