Breath Holding Spells in Children with Long QT Syndrome.
BACKGROUND
Long QT syndrome (LQTS) is a genetic heart rhythm disorder that may present with syncope, seizures, or sudden cardiac death. Breath holding spells (BHS) occur in 5% of all children and have been noted in children with LQTS anecdotally. The purpose of this study was to determine the frequency of BHS in children diagnosed with LQTS at ≤5 years of age.


METHODS
A retrospective review was performed to identify children diagnosed with LQTS who were ≤5 years old at initial presentation to our LQTS clinic from August 1999 to November 2013. The mean length of follow-up was 6.4 ± 2.8 years. The electronic medical records were reviewed for clinical presentation of BHS, as well as LQTS-associated symptoms, diagnostic tests, and treatment.


RESULTS
The study cohort consisted of 115 children with LQTS (58% male; median age at diagnosis, 11 months [range, birth to 5 years]; mean corrected QT interval (QTc), 478 ± 60 milliseconds). At presentation, 80% of patients were asymptomatic. Genetic testing revealed type 1 LQTS (LQT1) in 48%. Overall, 5 of 115 patients (4.3%) had BHS (2 of 5 [40%] male, mean QTc: 492 ± 14 milliseconds, 4 [80%] with family history of LQTS). BHS were the presenting symptom in 1 of 23 symptomatic patients (4.3%). All BHS occurred in patients with LQT1 (P = .02).


CONCLUSIONS
Although BHS among children with LQTS are relatively rare and occur at similar frequency as the general population, they can be the presenting symptom for a heart rhythm disorder. Careful attention to BHS is important to distinguish an innocent BHS from a potential LQTS-triggered cardiac event so that proper treatment is initiated.
Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minn, USA.
Jeffrey A
JA
Robinson
Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minn, USA.|Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minn, USA.
J Martijn
JM
Bos
Division of Pediatric Cardiology, University of Utah, Salt Lake City, Utah, USA.
Susan P
SP
Etheridge
Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minn, USA.|Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minn, USA.|Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minn, USA.
Michael J
MJ
Ackerman
D000367:Age Factors; D062485:Breath Holding; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004562:Electrocardiography; D057286:Electronic Health Records; D005260:Female; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006339:Heart Rate; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008133:Long QT Syndrome / Q000150:complications / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D010641:Phenotype; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014589:Utah
Breath Holding Spells; Children; Long QT Syndrome; Spells; Torsades de Pointes