The role of the epinephrine test in the diagnosis and management of children suspected of having congenital long QT syndrome.
The epinephrine test has been shown to be a powerful tool to predict the genotype of congenital long QT syndrome (LQTS). The aim of this study was to evaluate its role in the diagnosis and management of LQTS in children. The test (using the Shimizu protocol) was conducted in patients with some evidence of LQTS but in whom clinical and management decisions were challenging (n = 41, age 9.6 +/- 3.9 years, 19 female). LQT1, LQT2, and negative responses to epinephrine were obtained in 16, 5, and 20 subjects, respectively. LQTS gene positivity was obtained in two subjects. Beta-blocker therapy was started in all subjects with a positive epinephrine response (n = 21) and in some negative responders because of their strong LQTS phenotype (n = 10). No therapy was given to the subset with less convincing features of LQTS who had also responded negatively to epinephrine (n = 10). Follow-up for 3.0 +/- 2 years was uneventful in both management groups. Due to the discordance with genotyping, the epinephrine test cannot be used to diagnose genotype-positive LQTS but when used in combination with phenotype assessment and genetic screening, it could enable better management decisions.
Clur
Sally-Ann B
SA
Department of Pediatric Cardiology, Emma Children's Hospital, Academic Medical Centre, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands. s.a.clur@amc.uva.nl
Chockalingam
Priya
P
Filippini
Luc H
LH
Widyanti
Ari P
AP
Van Cruijsen
Marc
M
Blom
Nico A
NA
Alders
Mariel
M
Hofman
Nynke
N
Wilde
Arthur A M
AA
D000293:Adolescent; D000322:Adrenergic Agonists / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000187:drug effects; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D004837:Epinephrine / Q000009:adverse effects; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing; D005838:Genotype; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D010641:Phenotype; D011237:Predictive Value of Tests
D000322:Adrenergic Agonists; D004837:Epinephrine