Population-Based Study Found Low Risk of Misdiagnosing Long QT Syndrome as Breath-Holding Spells in Swedish Children

An electrocardiogram is commonly recommended in breath-holding spell management, mainly to rule out long QT syndrome. This retrospective study investigated the risk of long QT syndrome being misdiagnosed as breath-holding spells in a paediatric population in southern Sweden.

Data on patient characteristics and diagnostic findings were reviewed for patients aged < 10 years who were diagnosed with long QT syndrome between 2004 and 2018.

Sixteen children were diagnosed with long QT syndrome; 10 were diagnosed through genetic screening, 4 following perinatal cardiac symptoms, and 2 due to episodes of syncope or seizures later diagnosed as epilepsy and breath-holding spells. Three patients were > 24 months old at suspicion of long QT syndrome, and 10 were < 3 months old. No patient exhibited symptoms directly attributable to long QT syndrome, and no diagnosis of long QT syndrome was delayed due to suspicion of or misdiagnosis as breath-holding spells.

The number of symptomatic long QT syndrome cases overlapping with the presentation of breath-holding spells is likely small. The findings of this study suggest that children < 3 months old with suspected breath-holding spells should undergo an electrocardiogram.