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Wojciech Zareba - One of the best experts on this subject based on the ideXlab platform.
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beta blocker efficacy in high risk patients with the Congenital long qt Syndrome types 1 and 2 implications for patient management
Journal of Cardiovascular Electrophysiology, 2010Co-Authors: Ilan Goldenberg, Arthur J. Moss, James Bradley, Scott Mcnitt, Slava Polonsky, Jennifer L Robinson, Mark L Andrews, Wojciech ZarebaAbstract:Background β-blockers are the mainstay therapy in patients with the Congenital Long-QT Syndrome (LQTS) types 1 and 2. However, limited data exist regarding the efficacy and limitations of this form of medical management within high-risk subsets of these populations.
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Beta‐Blocker Efficacy in High‐Risk Patients with the Congenital Long‐QT Syndrome Types 1 and 2: Implications for Patient Management
Journal of cardiovascular electrophysiology, 2010Co-Authors: Ilan Goldenberg, Arthur J. Moss, James Bradley, Scott Mcnitt, Slava Polonsky, Jennifer L Robinson, Mark L Andrews, Wojciech ZarebaAbstract:Background β-blockers are the mainstay therapy in patients with the Congenital Long-QT Syndrome (LQTS) types 1 and 2. However, limited data exist regarding the efficacy and limitations of this form of medical management within high-risk subsets of these populations.
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Congenital long QT Syndrome: considerations for primary care physicians.
Cleveland Clinic journal of medicine, 2008Co-Authors: Ethan Levine, Spencer Rosero, Adam S. Budzikowski, Arthur J. Moss, Wojciech Zareba, James P. DaubertAbstract:Congenital long QT Syndrome is an inherited disorder of cardiac repolarization that predisposes to syncope and to sudden death from polymorphic ventricular tachycardia. The disorder should be suspected when the electrocardiogram shows characteristic QT abnormalities, or when there is a family history of long QT Syndrome or of an event that raises suspicion of long QT Syndrome, such as sudden death, syncope, or ill-defined "seizure" disorder. We can now classify some types of Congenital long QT Syndrome according to their genetic mutations and their triggers, such as exercise, rest, or startle.
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Heart Rate Variability in Patients with Congenital Long QT Syndrome
Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology Inc, 2001Co-Authors: Juha S. Perkiömäki, Wojciech Zareba, Jean-philippe Couderc, Arthur J. MossAbstract:Background: The Congenital long QT Syndrome (LQTS) affecting myocardial repolarization is caused by mutations in different cardiac potassium or sodium channel genes. Adrenergic triggers are known to initiate life-threatening torsade de pointes ventricular tachycardias in LQTS patients, and anti-adrenergic therapy has been shown to be effective in many cases. Despite this well-documented adrenergic component, the data about autonomic modulation of the heart rate in LQTS, as described by heart rate variability (HRV) analysis, are very limited. Methods: Conventional time- and frequency-domain and newer nonlinear measures of HRV were compared in resting conditions among 27 LQTS patients with gene mutations at the LQT1 (n = 8), LQT2 (n = 10) or LQT3 (n = 9) loci and 34 LQTS noncarrier family members. Results: None of the conventional time- or frequency-domain or newer nonlinear measures of HRV differed significantly between the LQTS carriers and LQTS noncarriers or between the LQT1, LQT2, and LQT3 carriers. Conclusions: These findings suggest that baseline cardiac autonomic modulation of the heart rate measured in resting conditions by traditional or newer nonlinear measures of HRV is not altered in LQTS patients. Furthermore, no differences are observed in HRV parameters between LQTS patients with potassium (KvLQT1, HERG), and sodium (SCN5A) ion channel gene mutations. HRV analysis in resting conditions does not improve phenotypic characterization of LQTS patients. A.N.E. 2001;6(4):298–304
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Effectiveness and Limitations of β-Blocker Therapy in Congenital Long-QT Syndrome
Circulation, 2000Co-Authors: Arthur J. Moss, G. Michael Vincent, Wojciech Zareba, Peter J. Schwartz, W. Jackson Hall, Richard S. Crampton, Jesaia Benhorin, Emanuela H. Locati, Silvia G. Priori, Carlo NapolitanoAbstract:Background—β-blockers are routinely prescribed in Congenital Long-QT Syndrome (LQTS), but the effectiveness and limitations of β-blockers in this disorder have not been evaluated. Methods and Results—The study population comprised 869 LQTS patients treated with β-blockers. Effectiveness of β-blockers was analyzed during matched periods before and after starting β-blocker therapy, and by survivorship methods to determine factors associated with cardiac events while on prescribed β-blockers. After initiation of β-blockers, there was a significant (P
Babak Bozorgnia - One of the best experts on this subject based on the ideXlab platform.
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Influence of Pregnancy in Patients With Congenital Long QT Syndrome.
Cardiology in Review, 2017Co-Authors: Lohit Garg, Jalaj Garg, Amy M Ahnert, Neeraj Shah, Raman Dusaj, Parasuram Krishnamoorthy, Babak BozorgniaAbstract:: Congenital long QT Syndrome (LQTS) is a disorder of myocardial repolarization and is characterized by a prolonged QT interval on an electrocardiogram. A prolonged QT predisposes patients to an increased risk of syncope and sudden cardiac death secondary to polymorphic ventricular tachycardia. Several mutations linked to the LQTS have been identified, the most common of which have been found in the potassium channel KCNQ1 (LQT1) and hERG (LQT2) genes and in the sodium channel SCN5A (LQT3) gene. Female sex is an independent risk factor for the development of torsades de pointes in LQTS. Furthermore, although pregnancy may be associated with protection against cardiac events in LQTS, the 9-month postpartum period represents a time of increased arrhythmogenicity. Interestingly, these cardiac events during the postpartum period are more common in patients with LQT2. The precise mechanisms that influence the cardiac repolarization during the postpartum period are unclear. Beta-blockers are considered reasonably safe during pregnancy and should be continued or initiated in patients with LQTS to reduce the risk of cardiac events. Implantable cardioverter defibrillators are safe in pregnancy, and there is no evidence that pregnant women with these devices are at any greater risk for adverse complications solely on the grounds of having the device.
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Influence of Pregnancy in Patients With Congenital Long QT Syndrome.
Cardiology in Review, 2017Co-Authors: Lohit Garg, Jalaj Garg, Amy M Ahnert, Neeraj Shah, Raman Dusaj, Parasuram Krishnamoorthy, Babak BozorgniaAbstract:: Congenital long QT Syndrome (LQTS) is a disorder of myocardial repolarization and is characterized by a prolonged QT interval on an electrocardiogram. A prolonged QT predisposes patients to an increased risk of syncope and sudden cardiac death secondary to polymorphic ventricular tachycardia. Several mutations linked to the LQTS have been identified, the most common of which have been found in the potassium channel KCNQ1 (LQT1) and hERG (LQT2) genes and in the sodium channel SCN5A (LQT3) gene. Female sex is an independent risk factor for the development of torsades de pointes in LQTS. Furthermore, although pregnancy may be associated with protection against cardiac events in LQTS, the 9-month postpartum period represents a time of increased arrhythmogenicity. Interestingly, these cardiac events during the postpartum period are more common in patients with LQT2. The precise mechanisms that influence the cardiac repolarization during the postpartum period are unclear. Beta-blockers are considered reasonably safe during pregnancy and should be continued or initiated in patients with LQTS to reduce the risk of cardiac events. Implantable cardioverter defibrillators are safe in pregnancy, and there is no evidence that pregnant women with these devices are at any greater risk for adverse complications solely on the grounds of having the device.
Arthur J. Moss - One of the best experts on this subject based on the ideXlab platform.
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beta blocker efficacy in high risk patients with the Congenital long qt Syndrome types 1 and 2 implications for patient management
Journal of Cardiovascular Electrophysiology, 2010Co-Authors: Ilan Goldenberg, Arthur J. Moss, James Bradley, Scott Mcnitt, Slava Polonsky, Jennifer L Robinson, Mark L Andrews, Wojciech ZarebaAbstract:Background β-blockers are the mainstay therapy in patients with the Congenital Long-QT Syndrome (LQTS) types 1 and 2. However, limited data exist regarding the efficacy and limitations of this form of medical management within high-risk subsets of these populations.
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Beta‐Blocker Efficacy in High‐Risk Patients with the Congenital Long‐QT Syndrome Types 1 and 2: Implications for Patient Management
Journal of cardiovascular electrophysiology, 2010Co-Authors: Ilan Goldenberg, Arthur J. Moss, James Bradley, Scott Mcnitt, Slava Polonsky, Jennifer L Robinson, Mark L Andrews, Wojciech ZarebaAbstract:Background β-blockers are the mainstay therapy in patients with the Congenital Long-QT Syndrome (LQTS) types 1 and 2. However, limited data exist regarding the efficacy and limitations of this form of medical management within high-risk subsets of these populations.
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Congenital long QT Syndrome: considerations for primary care physicians.
Cleveland Clinic journal of medicine, 2008Co-Authors: Ethan Levine, Spencer Rosero, Adam S. Budzikowski, Arthur J. Moss, Wojciech Zareba, James P. DaubertAbstract:Congenital long QT Syndrome is an inherited disorder of cardiac repolarization that predisposes to syncope and to sudden death from polymorphic ventricular tachycardia. The disorder should be suspected when the electrocardiogram shows characteristic QT abnormalities, or when there is a family history of long QT Syndrome or of an event that raises suspicion of long QT Syndrome, such as sudden death, syncope, or ill-defined "seizure" disorder. We can now classify some types of Congenital long QT Syndrome according to their genetic mutations and their triggers, such as exercise, rest, or startle.
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Heart Rate Variability in Patients with Congenital Long QT Syndrome
Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology Inc, 2001Co-Authors: Juha S. Perkiömäki, Wojciech Zareba, Jean-philippe Couderc, Arthur J. MossAbstract:Background: The Congenital long QT Syndrome (LQTS) affecting myocardial repolarization is caused by mutations in different cardiac potassium or sodium channel genes. Adrenergic triggers are known to initiate life-threatening torsade de pointes ventricular tachycardias in LQTS patients, and anti-adrenergic therapy has been shown to be effective in many cases. Despite this well-documented adrenergic component, the data about autonomic modulation of the heart rate in LQTS, as described by heart rate variability (HRV) analysis, are very limited. Methods: Conventional time- and frequency-domain and newer nonlinear measures of HRV were compared in resting conditions among 27 LQTS patients with gene mutations at the LQT1 (n = 8), LQT2 (n = 10) or LQT3 (n = 9) loci and 34 LQTS noncarrier family members. Results: None of the conventional time- or frequency-domain or newer nonlinear measures of HRV differed significantly between the LQTS carriers and LQTS noncarriers or between the LQT1, LQT2, and LQT3 carriers. Conclusions: These findings suggest that baseline cardiac autonomic modulation of the heart rate measured in resting conditions by traditional or newer nonlinear measures of HRV is not altered in LQTS patients. Furthermore, no differences are observed in HRV parameters between LQTS patients with potassium (KvLQT1, HERG), and sodium (SCN5A) ion channel gene mutations. HRV analysis in resting conditions does not improve phenotypic characterization of LQTS patients. A.N.E. 2001;6(4):298–304
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Effectiveness and Limitations of β-Blocker Therapy in Congenital Long-QT Syndrome
Circulation, 2000Co-Authors: Arthur J. Moss, G. Michael Vincent, Wojciech Zareba, Peter J. Schwartz, W. Jackson Hall, Richard S. Crampton, Jesaia Benhorin, Emanuela H. Locati, Silvia G. Priori, Carlo NapolitanoAbstract:Background—β-blockers are routinely prescribed in Congenital Long-QT Syndrome (LQTS), but the effectiveness and limitations of β-blockers in this disorder have not been evaluated. Methods and Results—The study population comprised 869 LQTS patients treated with β-blockers. Effectiveness of β-blockers was analyzed during matched periods before and after starting β-blocker therapy, and by survivorship methods to determine factors associated with cardiac events while on prescribed β-blockers. After initiation of β-blockers, there was a significant (P
Michael J Ackerman - One of the best experts on this subject based on the ideXlab platform.
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beta blockers in the treatment of Congenital long qt Syndrome is one beta blocker superior to another
Journal of the American College of Cardiology, 2014Co-Authors: A. A. Wilde, Michael J AckermanAbstract:The most common primary inherited arrhythmia Syndrome is the Congenital long QT Syndrome (LQTS). Prolonged QT interval on the electrocardiogram (ECG) is the signature feature of this disease, which is associated with an increased propensity to (arrhythmogenic) syncope and sudden death. The diagnosis
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Genotype- and Phenotype-Guided Management of Congenital Long QT Syndrome
Current problems in cardiology, 2013Co-Authors: John R. Giudicessi, Michael J AckermanAbstract:Congenital long QT Syndrome (LQTS) is a genetically heterogeneous group of heritable disorders of myocardial repolarization linked by the shared clinical phenotype of QT prolongation on electrocardiogram and an increased risk of potentially life-threatening cardiac arrhythmias. At the molecular level, mutations in 15 distinct LQTS-susceptibility genes that encode ion channel pore-forming α-subunits and accessory β-subunits central to the electromechanical function of the heart have been implicated in its pathogenesis. Over the past 2 decades, our evolving understanding of the electrophysiological mechanisms by which specific genetic substrates perturb the cardiac action potential has translated into vastly improved approaches to the diagnosis, risk stratification, and treatment of patients with LQTS. In this review, we describe how our understanding of the molecular underpinnings of LQTS has yielded numerous clinically meaningful genotype-phenotype correlations and how these insights have translated into genotype- and phenotype-guided approaches to the clinical management of LQTS.
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Left ventricular noncompaction Syndrome masquerading or misdiagnosed as Congenital long QT Syndrome: remember QT prolongation does not equal long QT Syndrome.
Congenital heart disease, 2011Co-Authors: Mira A. Coleman, J. Martijn Bos, Sabrina D. Phillips, Joseph J. Souza, Michael J AckermanAbstract:Distinguishing Congenital long QT Syndrome from QT prolongation caused by drugs or a different underlying disease process is essential for selecting the proper treatment. Herein, we present a case of a patient referred for left cardiac sympathetic denervation as a last resort treatment option for her 19-year standing diagnosis of long QT Syndrome with malignant ventricular fibrillation. However, based on her atypical clinical course and additional imaging studies, a diagnosis of left ventricular noncompaction, rather than long QT Syndrome, was made. She left the clinic with a drastically different treatment plan and an improved quality of life. Because many cardiac and noncardiac diseases can demonstrate QT prolongation on electrocardiogram, all possible diagnoses should be considered before diagnosing a patient with Congenital long QT Syndrome especially with regard to the profound treatment implications and genetic follow-up in family members.
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Genotype-phenotype relationships in Congenital long QT Syndrome
Journal of Electrocardiology, 2005Co-Authors: Michael J AckermanAbstract:In the United States, more than 300000 individuals die suddenly each year because of a fatal ventricular arrhythmia stemming from coronary artery disease in most cases. Although less than 1% of these sudden cardiac deaths are attributed to a cardiac channelopathy such as Congenital long QT Syndrome (LQTS), these deaths are particularly tragic. For example, there is the 3-year-old girl who died while playing in the sandbox, the 13-year-old teenager who dived into the pool and failed to resurface, the 33-year-old new mother who died suddenly while breastfeeding her newborn, and the healthy 60-year-old who died suddenly while taking an antibiotic. The fundamental culprit for each of these LQTS tragedies was a genetic defect in a gene(s) encoding a critical ion channel(s) that orchestrates the beating heart [1,2]. Although the first chromosomal location was established in 1991, public revelation of the sentinel discovery that cardiac channel mutations conferred the pathogenic mechanism for LQTS occurred on March 10, 1995. Now more than 10 years ago, these tandem publications appearing in Cell from Dr Keating’s laboratory demonstrated mutations in both the KCNH2-encoded HERG potassium channel and the SCN5A-encoded cardiac sodium channel in several families with Congenital LQTS [3,4]. Today, more than 400 mutations scattered among 5 cardiac channel genes
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prenatal molecular genetic diagnosis of Congenital long qt Syndrome by strategic genotyping
American Journal of Cardiology, 2004Co-Authors: David J Tester, Jorge Mccormack, Michael J AckermanAbstract:We demonstrate how genetic testing enabled a molecular prenatal diagnosis of Congenital long QT Syndrome in a 20-week fetus presenting with fetal bradycardia in the setting of maternal β-blocker therapy. Before prenatal testing, strategic genotyping, based on a family history of a near drowning, was performed on a 3-generation family with clinically diagnosed long QT Syndrome in which the affected mother was pregnant.
Elizabeth S. Kaufman - One of the best experts on this subject based on the ideXlab platform.
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NON-SUSTAINED MICROVOLT LEVEL T-WAVE ALTERNANS IN Congenital LONG QT Syndrome TYPES 1 AND 2
Journal of the American College of Cardiology, 2016Co-Authors: Jovil A. Kannampuzha, Bartholomew White, Sravani Avula, Stephen J. Ganocy, Peter J. Leo, Elizabeth S. KaufmanAbstract:Congenital long QT Syndrome (LQTS) is a group of inherited disorders with predisposition to torsades de pointes ventricular tachycardia during adrenergic stimulation, with subtypes LQT1 and LQT2 being most common. Microvolt T-wave alternans (MTWA), a beat-to-beat fluctuation in T-wave amplitude and
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Arrhythmic risk in Congenital long QT Syndrome
Journal of electrocardiology, 2011Co-Authors: Elizabeth S. KaufmanAbstract:One of the most important and challenging aspects of caring for patients with Congenital long QT Syndrome (LQTS) is assessing an individual's risk of sudden cardiac death (SCD) because of torsades de pointes. Current risk assessment integrates clinical and genetic features known to be associated with SCD, but more accurate methods of risk assessment could lead to more appropriate use of therapies, potentially saving lives and avoiding overtreatment. Conventional indices of risk include sex, age, extent of QT prolongation, history of symptoms (syncope or aborted SCD), and genetic subtype. The biophysical properties of specific mutations (eg, those that affect transmembrane segments of the ion channel protein or those that cause a dominant negative effect on ion channel function vs haplotype insufficiency) also contribute to risk. A growing body of basic mechanistic and clinical evidence points to heterogeneity of repolarization as a potent determinant of risk in LQTS patients. Mechanistically, heterogeneities of repolarization provide substrate for reentry, which likely causes perpetuation of torsades de pointes. Clinical markers that reflect heterogeneity of repolarization include abnormal microvolt-level T wave alternans, increased Tpeak-end interval, and dispersion of mechanical contraction time. The optimal methodology for using these indices as risk predictors in LQTS remains under active investigation. Further studies are needed to determine how indices of heterogeneity such as microvolt-level T wave alternans, Tpeak-end interval, and dispersion of mechanical contraction can be incorporated into models of risk prediction in LQTS, both for initial risk stratification and for assessment of efficacy of therapies.
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Electrocardiographic prediction of abnormal genotype in Congenital long QT Syndrome: experience in 101 related family members.
Journal of cardiovascular electrophysiology, 2001Co-Authors: Elizabeth S. Kaufman, Peter J. Schwartz, Silvia G. Priori, Carlo Napolitano, Sudha K. Iyengar, Robert C. Elston, Audrey H. Schnell, Eiran Z. Gorodeski, Guhan Rammohan, Nael O. BahhurAbstract:Prediction of Congenital Long QT Syndrome. Introduction: Previous studies showed that diagnosing Congenital long QT Syndrome (LQTS) is dife cult due to variable penetrance and genetic heterogeneity, especially when subjects from multiple families with diverse mutations are combined. We hypothesized that a combination of clinical and ECG techniques could identify gene carriers within a single family with Congenital LQTS. Methods and Results: One hundred one genotyped members of a family with LQTS, including 26 carriers of a HERG mutation, underwent history and ECG analysis. Forty-eight family members also underwent exercise testing with QT and T wave alternans (TWA) analysis and 24-hour Holter monitoring with QT and heart rate variability analysis. A logistic regression model, which included age, gender, QTc, and QTc by age, provided the best prediction of gene carrier status, although there was substantial overlap (78%) of QTc among subjects with and without the mutation. QTc was not helpful as a discriminator in children 13 years. TWA (observed infrequently) did not add signie cantly to the model’s ability to predict abnormal genotype. Conclusion: Even in this homogeneous LQTS population, the phenotype was so variable that clinical and detailed ECG analyses did not permit an accurate diagnosis of gene carrier status, especially in children. Sustained microvolt TWA was a specie c (100%) but insensitive (18%) marker for LQTS. Its ability to predict risk of arrhythmia in this population remains to be determined. Genetic testing serves an essential role in screening for carriers of LQTS. (J Cardiovasc Electrophysiol, Vol. 12, pp. 455-461, April 2001)