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. Copyright (c) 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
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. Copyright (c) 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Authors: James Rush Priest; Charles Gawad; Kristopher M Kahlig; Joseph K Yu; Thomas O'Hara; Patrick M Boyle; Sridharan Rajamani; Michael J Clark; Sarah T K Garcia; Scott Ceresnak; Jason Harris; Sean Boyle; Frederick E Dewey; Lindsey Malloy-Walton; Kyla Dunn; Megan Grove; Marco V Perez; Norma F Neff; Richard Chen; Katsuhide Maeda; Anne Dubin; Luiz Belardinelli; John West; Christian Antolik; Daniela Macaya; Thomas Quertermous; Natalia A Trayanova; Stephen R Quake; Euan A Ashley Journal: Proc Natl Acad Sci U S A Date: 2016-09-28 Impact factor: 11.205
Authors: James R Priest; Scott R Ceresnak; Frederick E Dewey; Lindsey E Malloy-Walton; Kyla Dunn; Megan E Grove; Marco V Perez; Katsuhide Maeda; Anne M Dubin; Euan A Ashley Journal: Heart Rhythm Date: 2014-06-25 Impact factor: 6.343
Authors: Christina M Hull; Christine E Genge; Yuki Hobbs; Kaveh Rayani; Eric Lin; Marvin Gunawan; Sanam Shafaattalab; Glen F Tibbits; Tom W Claydon Journal: Am J Physiol Regul Integr Comp Physiol Date: 2019-10-30 Impact factor: 3.619
Authors: Maully J Shah; Michael J Silka; Jennifer N Avari Silva; Seshadri Balaji; Cheyenne M Beach; Monica N Benjamin; Charles I Berul; Bryan Cannon; Frank Cecchin; Mitchell I Cohen; Aarti S Dalal; Brynn E Dechert; Anne Foster; Roman Gebauer; M Cecilia Gonzalez Corcia; Prince J Kannankeril; Peter P Karpawich; Jeffery J Kim; Mani Ram Krishna; Peter Kubuš; Martin J LaPage; Douglas Y Mah; Lindsey Malloy-Walton; Aya Miyazaki; Kara S Motonaga; Mary C Niu; Melissa Olen; Thomas Paul; Eric Rosenthal; Elizabeth V Saarel; Massimo Stefano Silvetti; Elizabeth A Stephenson; Reina B Tan; John Triedman; Nicholas H Von Bergen; Philip L Wackel Journal: Indian Pacing Electrophysiol J Date: 2021-07-29