TY - JOUR
T1 - Implantable cardioverter defibrillator therapy for congenital long QT syndrome
T2 - A single-center experience
AU - Horner, Justin M.
AU - Kinoshita, Masayoshi
AU - Webster, Tracy L.
AU - Haglund, Carla M.
AU - Friedman, Paul A.
AU - Ackerman, Michael J.
N1 - Funding Information:
Dr. Ackerman's research program is supported by the Mayo Clinic Windland Smith Rice Comprehensive Sudden Cardiac Death Program .
Funding Information:
Tracy Webster receives honoraria from Boston Scientific. Dr. Paul Friedman's research is supported by Medtronic , Boston Scientific , Bard , St. Jude Medical , Pfizer Intellectual Property Rights - Bard EP , Hewlett Packard , Medical Positioning, Inc. , Aegis Medical , NeoChord . Dr. Friedman is a consultant for Medtronic, Boston Scientific, and St. Jude Medical. However, none of these entities provided financial support for this study.
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2010/11
Y1 - 2010/11
N2 - Background Long QT syndrome's (LQTS) marked heterogeneity necessitates both evidence-based and individualized therapeutic approaches. Objective This study sought to analyze a single LQTS specialty center's experience regarding the relationship between risk factors and appropriate ventricular fibrillation (VF)terminating therapies among LQTS patients treated with an implantable cardioverter-defibrillator (ICD). Methods An internal review boardapproved, retrospective analysis of the electronic medical records of 459 patients with genetically confirmed LQTS including the 51 patients (14 LQT1, 22 LQT2, and 15 LQT3) who received an ICD from 2000 to 2010 was performed. Results Twelve patients (24%, 4 LQT1, 8 LQT2) experienced an appropriate, VF-terminating therapy with an average follow-up of 7.3 years, including 7 of 17 LQT2 female patients but none of the 15 LQT3 patients. Conversely, 15 (29%) patients (8 LQT3) have experienced an inappropriate shock. Secondary prevention indications (P = .008), non-LQT3 genotype (P = .02), QTc < 500 ms (P = .0008), documented syncope (P = .05), documented torsades de pointes (P = .003), and a negative family history (P = .0001) were most predictive of an appropriate therapy. Importantly, no LQT-related deaths have occurred among the 408 non-ICDtreated patients. Conclusion The vast majority of LQTS patients can be treated effectively without an ICD. Potentially life-saving therapies were rendered at a 5% to 6% per year rate among those selected for ICD therapy; similar inappropriate shock frequencies were also noted. Secondary prevention, genotype, and QTc predicted those most likely to receive appropriate therapy. Although the ICD implant frequency is greatest among LQT3 patients, the greatest "save" rate has occurred among LQT2 women, who were assessed to be at high risk.
AB - Background Long QT syndrome's (LQTS) marked heterogeneity necessitates both evidence-based and individualized therapeutic approaches. Objective This study sought to analyze a single LQTS specialty center's experience regarding the relationship between risk factors and appropriate ventricular fibrillation (VF)terminating therapies among LQTS patients treated with an implantable cardioverter-defibrillator (ICD). Methods An internal review boardapproved, retrospective analysis of the electronic medical records of 459 patients with genetically confirmed LQTS including the 51 patients (14 LQT1, 22 LQT2, and 15 LQT3) who received an ICD from 2000 to 2010 was performed. Results Twelve patients (24%, 4 LQT1, 8 LQT2) experienced an appropriate, VF-terminating therapy with an average follow-up of 7.3 years, including 7 of 17 LQT2 female patients but none of the 15 LQT3 patients. Conversely, 15 (29%) patients (8 LQT3) have experienced an inappropriate shock. Secondary prevention indications (P = .008), non-LQT3 genotype (P = .02), QTc < 500 ms (P = .0008), documented syncope (P = .05), documented torsades de pointes (P = .003), and a negative family history (P = .0001) were most predictive of an appropriate therapy. Importantly, no LQT-related deaths have occurred among the 408 non-ICDtreated patients. Conclusion The vast majority of LQTS patients can be treated effectively without an ICD. Potentially life-saving therapies were rendered at a 5% to 6% per year rate among those selected for ICD therapy; similar inappropriate shock frequencies were also noted. Secondary prevention, genotype, and QTc predicted those most likely to receive appropriate therapy. Although the ICD implant frequency is greatest among LQT3 patients, the greatest "save" rate has occurred among LQT2 women, who were assessed to be at high risk.
KW - Genetic testing
KW - Implantable cardioverter defibrillator
KW - Ion channels
KW - Long QT syndrome
KW - Sudden cardiac death
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U2 - 10.1016/j.hrthm.2010.08.023
DO - 10.1016/j.hrthm.2010.08.023
M3 - Article
C2 - 20816872
AN - SCOPUS:78149268639
SN - 1547-5271
VL - 7
SP - 1616
EP - 1622
JO - Heart rhythm
JF - Heart rhythm
IS - 11
ER -