Syncope in children and adolescents living in north-eastern Poland - scope of causes

Syncope in hypertrophic cardiomyopathy (part I): An updated systematic review and meta-analysis

AIMS

To describe the proportion of patients with syncope among those affected by hypertrophic cardiomyopathy (HCM) and the relevance of syncope as risk factor for sudden cardiac death and life-threatening arrhythmic events.

METHOD AND RESULTS

Systematic review of original articles that assessed syncope in HCM patients. Literature search of PubMed including all English publications from 1973 to 2021.We found 57 articles for a total of 21.791 patients; of these, 14 studies reported on arrhythmic events in the follow-up. Syncope was reported in 15.8% (3.452 of 21.791) patients. It was considered unexplained in 91% of cases. Life-threatening arrhythmic events occurred in 3.6% of non-syncopal patients and in 7.7% of syncopal patients during a mean follow-up of 5.6 years. A relative risk of 1.99 (95%CI 1.39 to 2.86) was estimated for syncope patients by the random effect model using Haldane continuity correction for 0 events.

CONCLUSIONS

In the current practice, the cause of syncope remained unexplained in most patients affected by HCM. The management of patients seems mainly driven by risk stratification rather than identification of the aetiology of syncope. There is a need of precise instructions how to apply the recommendations of current guidelines to this disease, which tests are indicated and how to interpret their findings. The protocol was registered in Prospero (ID: 275963).

Syncope is a frequently under-diagnosed condition in infants and toddlers and has similar features to those seen in adolescents and adults

AIM

Vagal syncope may not be readily recognised by the caregivers of younger children, often leading to extensive diagnostic evaluation. Our aim was to determine the characteristics of syncope in younger children and to assess whether this age group was more prone to undergoing extensive diagnostic work-ups and receiving wrong aetiological diagnoses.

METHODS

We collected clinical data on children up to six years of age, referred to our paediatric neurology clinic between 2007 and 2014 following one or more episodes of sudden loss of consciousness.

RESULTS

A family history of syncope was present in 59.5% of the 37 children, and a trigger for syncope was identified in 30 children. Most of the episodes were short, with witnesses reporting an immediate or quick recovery. Most of the children underwent diagnostic procedures, particularly an electroencephalogram, and all the results were normal. Epilepsy did not develop in any of these cases. Syncope recurred in 22 patients during a two-year follow-up.

CONCLUSION

Vagal syncope had similar features in toddlers and young children to those seen in adolescents and adults. Its diagnosis should be considered following loss of consciousness due to an identifiable trigger and rapidly regaining consciousness to avoid unnecessary diagnostic procedures and hospitalisation.