TY - JOUR
T1 - Congenital long QT syndrome and 2:1 atrioventricular block
T2 - An optimistic outcome in the current era
AU - Aziz, Peter F.
AU - Tanel, Ronn E.
AU - Zelster, Ilana J.
AU - Pass, Robert H.
AU - Wieand, Tammy S.
AU - Vetter, Victoria L.
AU - Vogel, R. Lee
AU - Shah, Maully J.
PY - 2010/6
Y1 - 2010/6
N2 - Background: Previous studies of patients with long QT syndrome (LQTS) and 2:1 atrioventricular block (AVB) have reported a mortality rate greater than 50% during infancy. Objective: The purpose of this study was to determine the outcome of this high-risk population in the current era. Methods: A retrospective study from four tertiary care pediatric centers assessed patients with congenital LQTS and 2:1 AVB from January 2000 to January 2009. All neonates who presented with 2:1 AVB and prolonged QTc unrelated to medication were included in the study. Statistical analysis was performed using a paired t-test. Medical records were reviewed for ECG findings, genotype, medications, and device therapy. Results: Twelve patients that met the inclusion criteria were identified. All patients underwent diagnostic ECG in the first 24 hours of life. The average QTc interval prior to therapy was 616 ± 99 ms (range 531-840 ms). Over a follow-up period of 71 ± 45 months (range 15-158 months), 11 of 12 patients received devices (8 permanent pacemaker, 3 implantable cardioverter-defibrillator). Average age of device placement was 48 months (median 2 months, range 3 days to 10.5 years). All patients were treated with beta-blockers; mexiletine was added in three patients, and mexiletine and flecainide were added in one patient. Three (25%) patients experienced torsades de pointes while receiving beta-blockers, one of which was refractory to medical therapy. This patient underwent left cardiac sympathetic denervation and implantable cardioverter-defibrillator placement. Genotyping was available for 6 (50%) patients (2 SCN5A mutation, 4 KCNH2 mutation). At last follow-up, no mortality was observed. Follow-up QTc intervals had decreased (mean 480 ± 20 ms, range 450-507 ms, P <.002). Conclusion: Management of patients with LQTS and 2:1 AVB presents unique challenges. Despite historical data indicating poor prognosis, our study represents a cohort of high-risk LQTS patients with a relatively optimistic outcome. This finding reflects early diagnosis and intervention, coupled with improved management strategies, in the current era.
AB - Background: Previous studies of patients with long QT syndrome (LQTS) and 2:1 atrioventricular block (AVB) have reported a mortality rate greater than 50% during infancy. Objective: The purpose of this study was to determine the outcome of this high-risk population in the current era. Methods: A retrospective study from four tertiary care pediatric centers assessed patients with congenital LQTS and 2:1 AVB from January 2000 to January 2009. All neonates who presented with 2:1 AVB and prolonged QTc unrelated to medication were included in the study. Statistical analysis was performed using a paired t-test. Medical records were reviewed for ECG findings, genotype, medications, and device therapy. Results: Twelve patients that met the inclusion criteria were identified. All patients underwent diagnostic ECG in the first 24 hours of life. The average QTc interval prior to therapy was 616 ± 99 ms (range 531-840 ms). Over a follow-up period of 71 ± 45 months (range 15-158 months), 11 of 12 patients received devices (8 permanent pacemaker, 3 implantable cardioverter-defibrillator). Average age of device placement was 48 months (median 2 months, range 3 days to 10.5 years). All patients were treated with beta-blockers; mexiletine was added in three patients, and mexiletine and flecainide were added in one patient. Three (25%) patients experienced torsades de pointes while receiving beta-blockers, one of which was refractory to medical therapy. This patient underwent left cardiac sympathetic denervation and implantable cardioverter-defibrillator placement. Genotyping was available for 6 (50%) patients (2 SCN5A mutation, 4 KCNH2 mutation). At last follow-up, no mortality was observed. Follow-up QTc intervals had decreased (mean 480 ± 20 ms, range 450-507 ms, P <.002). Conclusion: Management of patients with LQTS and 2:1 AVB presents unique challenges. Despite historical data indicating poor prognosis, our study represents a cohort of high-risk LQTS patients with a relatively optimistic outcome. This finding reflects early diagnosis and intervention, coupled with improved management strategies, in the current era.
KW - Atrioventricular block
KW - Long QT syndrome
KW - Torsades de pointes
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U2 - 10.1016/j.hrthm.2010.02.035
DO - 10.1016/j.hrthm.2010.02.035
M3 - Article
C2 - 20197117
AN - SCOPUS:77952539116
SN - 1547-5271
VL - 7
SP - 781
EP - 785
JO - Heart Rhythm
JF - Heart Rhythm
IS - 6
ER -