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Possible Susceptibility Genes for Intervention against Chemotherapy-Induced Cardiotoxicity. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4894625. [PMID: 33110473 PMCID: PMC7578723 DOI: 10.1155/2020/4894625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/07/2020] [Accepted: 07/30/2020] [Indexed: 12/12/2022]
Abstract
Recent therapeutic advances have significantly improved the short- and long-term survival rates in patients with heart disease and cancer. Survival in cancer patients may, however, be accompanied by disadvantages, namely, increased rates of cardiovascular events. Chemotherapy-related cardiac dysfunction is an important side effect of anticancer therapy. While advances in cancer treatment have increased patient survival, treatments are associated with cardiovascular complications, including heart failure (HF), arrhythmias, cardiac ischemia, valve disease, pericarditis, and fibrosis of the pericardium and myocardium. The molecular mechanisms of cardiotoxicity caused by cancer treatment have not yet been elucidated, and they may be both varied and complex. By identifying the functional genetic variations responsible for this toxicity, we may be able to improve our understanding of the potential mechanisms and pathways of treatment, paving the way for the development of new therapies to target these toxicities. Data from studies on genetic defects and pharmacological interventions have suggested that many molecules, primarily those regulating oxidative stress, inflammation, autophagy, apoptosis, and metabolism, contribute to the pathogenesis of cardiotoxicity induced by cancer treatment. Here, we review the progress of genetic research in illuminating the molecular mechanisms of cancer treatment-mediated cardiotoxicity and provide insights for the research and development of new therapies to treat or even prevent cardiotoxicity in patients undergoing cancer treatment. The current evidence is not clear about the role of pharmacogenomic screening of susceptible genes. Further studies need to done in chemotherapy-induced cardiotoxicity.
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Garris R, Vasudev R, Gupta P, Tiyyagura S, Shamoon F, Bikkina M. Brugada syndrome & AKAP9: Reconciling clinical findings with diagnostic uncertainty. J Electrocardiol 2019; 57:119-121. [PMID: 31654968 DOI: 10.1016/j.jelectrocard.2019.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/30/2019] [Accepted: 09/05/2019] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Brugada Syndrome typically presents with sudden nocturnal arrhythmias. Diagnosis may be challenging due to variable and transient electrocardiogram patterns and nondiagnostic provocation studies. Genetic testing can establish the etiology, but results may be inconclusive with variants of uncertain significance. CASE A 24-year-old male with family history of sudden cardiac death was found unresponsive due to seizure. He was hemodynamically stable. ECG showed saddle-back ST elevations in V1 and V2. Procainamide challenge was negative. We subsequently performed genetic testing, which demonstrated AKAP9 variant. DISCUSSION AKAP9 is a scaffolding protein that facilitates phosphorylation of delayed-rectifier potassium channels. The AKAP9 variant alters potassium current causing disordered repolarization and ventricular reentry. It has been previously linked to other channelopathies, but its pathogenicity is fully undetermined. CONCLUSION Genetic testing is a useful tool to determine the origin of channelopathy, but inconclusive results with variants of uncertain significance should be clinically correlated.
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Affiliation(s)
- Rana Garris
- Department of Internal Medicine, St. Joseph's Health, New York Medical College, Paterson, NJ, USA.
| | - Rahul Vasudev
- Department of Cardiology, St. Joseph's Health, New York Medical College, Paterson, NJ, USA
| | - Punita Gupta
- Department of Genetics, St. Joseph's Health, Paterson, NJ, USA.
| | - Satish Tiyyagura
- Department of Cardiology, St. Joseph's Health, New York Medical College, Paterson, NJ, USA; Department of Electrophysiology, St. Joseph's Health, Paterson, NJ, USA.
| | - Fayez Shamoon
- Department of Cardiology, St. Joseph's Health, New York Medical College, Paterson, NJ, USA.
| | - Mahesh Bikkina
- Department of Cardiology, St. Joseph's Health, New York Medical College, Paterson, NJ, USA.
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Liu Y, Bai F, Liu N, Ouyang F, Liu Q. The Warburg effect: A new insight into atrial fibrillation. Clin Chim Acta 2019; 499:4-12. [PMID: 31473195 DOI: 10.1016/j.cca.2019.08.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 08/23/2019] [Accepted: 08/28/2019] [Indexed: 12/28/2022]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia. Atrial remodeling, including electrical/structural/autonomic remodeling, plays a vital role in AF pathogenesis. All of these have been shown to contribute continuously to the self-perpetuating nature of AF. The Warburg effect was found to play important roles in tumor and non-tumor disease. Recently, lots of studies documented altered atrial metabolism in AF, but the specific mechanism and the impact of these changes upon AF initiation/progression remain unclear. In this article, we review the metabolic consideration in AF comprehensively and observe the footprints of the Warburg effect. We also summarize the signaling pathway involved in the Warburg effect during AF-HIF-1α and AMPK, and discuss their potential roles in AF maintenance and progression. In conclusion, we give the innovative idea that the Warburg effect exists in AF and promotes the progression of AF. Targeting it may provide new therapies for AF treatment.
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Affiliation(s)
- Yaozhong Liu
- Department of Cardiology, The Second Xiangya Hospital, Central South University, Hunan Province, China
| | - Fan Bai
- Department of Cardiology, The Second Xiangya Hospital, Central South University, Hunan Province, China
| | - Na Liu
- Department of Cardiology, The Second Xiangya Hospital, Central South University, Hunan Province, China
| | - Feifan Ouyang
- Department of Cardiology, Asklepios-Klinik St Georg, Hamburg, Germany
| | - Qiming Liu
- Department of Cardiology, The Second Xiangya Hospital, Central South University, Hunan Province, China.
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Faridi R, Tona R, Brofferio A, Hoa M, Olszewski R, Schrauwen I, Assir MZ, Bandesha AA, Khan AA, Rehman AU, Brewer C, Ahmed W, Leal SM, Riazuddin S, Boyden SE, Friedman TB. Mutational and phenotypic spectra of KCNE1 deficiency in Jervell and Lange-Nielsen Syndrome and Romano-Ward Syndrome. Hum Mutat 2019; 40:162-176. [PMID: 30461122 PMCID: PMC6328321 DOI: 10.1002/humu.23689] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/01/2018] [Accepted: 11/15/2018] [Indexed: 11/11/2022]
Abstract
KCNE1 encodes a regulatory subunit of the KCNQ1 potassium channel-complex. Both KCNE1 and KCNQ1 are necessary for normal hearing and cardiac ventricular repolarization. Recessive variants in these genes are associated with Jervell and Lange-Nielson syndrome (JLNS1 and JLNS2), a cardio-auditory syndrome characterized by congenital profound sensorineural deafness and a prolonged QT interval that can cause ventricular arrhythmias and sudden cardiac death. Some normal-hearing carriers of heterozygous missense variants of KCNE1 and KCNQ1 have prolonged QT intervals, a dominantly inherited phenotype designated Romano-Ward syndrome (RWS), which is also associated with arrhythmias and elevated risk of sudden death. Coassembly of certain mutant KCNE1 monomers with wild-type KCNQ1 subunits results in RWS by a dominant negative mechanism. This paper reviews variants of KCNE1 and their associated phenotypes, including biallelic truncating null variants of KCNE1 that have not been previously reported. We describe three homozygous nonsense mutations of KCNE1 segregating in families ascertained ostensibly for nonsyndromic deafness: c.50G>A (p.Trp17*), c.51G>A (p.Trp17*), and c.138C>A (p.Tyr46*). Some individuals carrying missense variants of KCNE1 have RWS. However, heterozygotes for loss-of-function variants of KCNE1 may have normal QT intervals while biallelic null alleles are associated with JLNS2, indicating a complex genotype-phenotype spectrum for KCNE1 variants.
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Affiliation(s)
- Rabia Faridi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 54550, Pakistan
| | - Risa Tona
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alessandra Brofferio
- Cardiology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health Clinical Center, Bethesda, MD 20892, USA
| | - Michael Hoa
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rafal Olszewski
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Muhammad Z.K. Assir
- Allama Iqbal Medical Research Centre, Jinnah Hospital Complex, Lahore 54550, Pakistan
| | - Akhtar A. Bandesha
- Cardiology Department, The Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Asma A. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore 54550, Pakistan
| | - Atteeq U. Rehman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carmen Brewer
- Audiology Unit, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD 20892, USA
| | - Wasim Ahmed
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Suzanne M. Leal
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sheikh Riazuddin
- Allama Iqbal Medical Research Centre, Jinnah Hospital Complex, Lahore 54550, Pakistan
| | - Steven E. Boyden
- Section on Genetics of Communication Disorders, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
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Desplantez T. Cardiac Cx43, Cx40 and Cx45 co-assembling: involvement of connexins epitopes in formation of hemichannels and Gap junction channels. BMC Cell Biol 2017; 18:3. [PMID: 28124623 PMCID: PMC5267329 DOI: 10.1186/s12860-016-0118-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background This review comes after the International Gap Junction Conference (IGJC 2015) and describes the current knowledge on the function of the specific motifs of connexins in the regulation of the formation of gap junction channels. Moreover the review is complemented by a summarized description of the distinct contribution of gap junction channels in the electrical coupling. Results Complementary biochemical and functional characterization on cell models and primary cells have improved our understanding on the oligomerization of connexins and the formation and the electrical properties of gap junction channels. Studies mostly focused cardiac connexins Cx43 and Cx40 expressed in myocytes, while Cx45 and Cx30.2 have been less investigated, for which main findings are reviewed to highlight their critical contribution in the formation of gap junction channels for ensuring the orchestrated electrical impulse propagation and coordination of atrial and ventricular contraction and heart function, whereas connexin dysfunction and remodeling are pro-arrhythmic factors. Common and specific motifs of residues identified in different domain of each type of connexin determine the connexin homo- and hetero-oligomerization and the channels formation, which leads to specific electrical properties. Conclusions These motifs and the resulting formation of gap junction channels are keys to ensure the tissue homeostasis and function in each connexin expression pattern in various tissues of multicellular organisms. Altogether, the findings to date have significantly improved our understanding on the function of the different connexin expression patterns in healthy and diseased tissues, and promise further investigations on the contribution in the different types of connexin.
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Affiliation(s)
- Thomas Desplantez
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Campus X. Arnozan, Avenue Haut Leveque, 33600, Pessac- Bordeaux, France. .,Univ. Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, F-33000, Bordeaux, France. .,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, F-33000, Bordeaux, France.
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Koh W, Wong C, Tang WHW. Genetic Predispositions to Heart Failure. CURRENT CARDIOVASCULAR RISK REPORTS 2016. [DOI: 10.1007/s12170-016-0525-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Santa Cruz A, Meşe G, Valiuniene L, Brink PR, White TW, Valiunas V. Altered conductance and permeability of Cx40 mutations associated with atrial fibrillation. J Gen Physiol 2015; 146:387-98. [PMID: 26503720 PMCID: PMC4621748 DOI: 10.1085/jgp.201511475] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/23/2015] [Indexed: 11/20/2022] Open
Abstract
Gap junctions ensure the rapid propagation of the action potential throughout the myocardium. Three mutant forms of connexin40 (Cx40; A96S, M163V, and G38D), the primary component of the atrial gap junction channel, are associated with atrial fibrillation and retain the ability to form functional channels. We determined the biophysical properties of these mutant gap junctions in transiently transfected HeLa and N2A cells. All three mutants showed macroscopic junctional conductances over the range of 0.5 to 40 nS, and voltage dependences comparable to those of wild-type (WT) Cx40. However, the unitary conductance of G38D channels was ∼1.6-fold higher than that of WT Cx40 channels (∼220 vs. ∼135 pS), whereas the unitary conductances of the A96S and M163V mutants were similar to that of WT Cx40. Furthermore, the M163V and G38D channels exhibited approximately two- and approximately fivefold higher permeability to the anionic dye Lucifer yellow (LY) relative to K+ (LY/K+) compared with that of WT Cx40, whereas A96S LY transfer was similar to that of WT (G38D > M163V > A96S ≈ Cx40WT). In contrast, G38D channels were almost impermeable to cationic ethidium bromide (EtBr), suggesting that G38D alters channel selectivity. Conversely, A96S and M163V channels showed enhanced EtBr permeability relative to WT Cx40, with the following permeability order: M163V > A96S > Cx40WT > G38D. Altered conductive and permeability properties of mutant channels suggest an essential role for Cx40-mediated biochemical and electrical coupling in cardiac tissues. The altered properties of the three single-base substitution mutants may play a role in mechanisms of reentry arrhythmias.
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Affiliation(s)
- Ana Santa Cruz
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
| | - Gülistan Meşe
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
| | - Laima Valiuniene
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
| | - Peter R Brink
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
| | - Virginijus Valiunas
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11792
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Arbour L, Asuri S, Whittome B, Polanco F, Hegele RA. The Genetics of Cardiovascular Disease in Canadian and International Aboriginal Populations. Can J Cardiol 2015; 31:1094-115. [DOI: 10.1016/j.cjca.2015.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 12/16/2022] Open
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Campuzano O, Allegue C, Brugada R. [Genetics of sudden unexplained death]. Med Clin (Barc) 2013; 142:265-9. [PMID: 24018251 DOI: 10.1016/j.medcli.2013.06.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
Abstract
Sudden unexplained death is defined by death without a conclusive diagnosis after autopsy and it is responsible for a large percentage of sudden deaths. The progressive interaction between genetics and forensics in post-mortem studies has identified inheritable alterations responsible for pathologies associated with arrhythmic sudden death. The genetic diagnosis of the deceased enables the undertaking of preventive measures in family members, many of them asymptomatic but at risk. The implications of this multidisciplinary translational medical approach are complex, requiring the dedication of a specialized team.
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Affiliation(s)
- Oscar Campuzano
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España
| | - Catarina Allegue
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España
| | - Ramon Brugada
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España.
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Association between severe toxicity of nilotinib and UGT1A1 polymorphisms in Japanese patients with chronic myelogenous leukemia. Int J Clin Oncol 2013; 19:391-6. [DOI: 10.1007/s10147-013-0562-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 04/09/2013] [Indexed: 11/28/2022]
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Cooley N, Ouyang K, McMullen JR, Kiriazis H, Sheikh F, Wu W, Mu Y, Du XJ, Chen J, Woodcock EA. No contribution of IP3-R(2) to disease phenotype in models of dilated cardiomyopathy or pressure overload hypertrophy. Circ Heart Fail 2012; 6:318-25. [PMID: 23258573 DOI: 10.1161/circheartfailure.112.972158] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND We investigated the contribution of inositol(1,4,5)-trisphosphate (Ins(1,4,5)P3 [IP3]) receptors (IP3-R) to disease progression in mouse models of dilated cardiomyopathy (DCM) and pressure overload hypertrophy. Mice expressing mammalian sterile 20-like kinase and dominant-negative phosphatidylinositol-3-kinase in heart (Mst1×dn-PI3K-2Tg; DCM-2Tg) develop severe DCM and conduction block, associated with increased expression of type 2 IP3-R (IP3-R(2)) and heightened generation of Ins(1,4,5)P3. Similar increases in Ins(1,4,5)P3 and IP3-R(2) are caused by transverse aortic constriction. METHODS AND RESULTS To evaluate the contribution of IP3-R(2) to disease progression, the DCM-2Tg mice were further crossed with mice in which the type 2 IP3-R (IP3-R(2)-/-) had been deleted (DCM-2Tg×IP3-R(2)-/-) and transverse aortic constriction was performed on IP3-R(2)-/- mice. Hearts from DCM-2Tg mice and DCM-2Tg×IP3-R(2)-/- were similar in terms of chamber dilatation, atrial enlargement, and ventricular wall thinning. Electrophysiological changes were also similar in the DCM-2Tg mice, with and without IP3-R(2). Deletion of IP3-R(2) did not alter the progression of heart failure, because DCM-2Tg mice with and without IP3-R(2) had similarly reduced contractility, increased lung congestion, and atrial thrombus, and both strains died between 10 and 12 weeks of age. Loss of IP3-R(2) did not alter the progression of hypertrophy after transverse aortic constriction. CONCLUSIONS We conclude that IP3-R(2) do not contribute to the progression of DCM or pressure overload hypertrophy, despite increased expression and heightened generation of the ligand, Ins(1,4,5)P3.
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Affiliation(s)
- Nicola Cooley
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
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Kitagawa K, Kawada K, Morita S, Inada M, Mitsuma A, Sawaki M, Iino S, Inden Y, Murohara T, Imai T, Ando Y. Prospective evaluation of corrected QT intervals and arrhythmias after exposure to epirubicin, cyclophosphamide, and 5-fluorouracil in women with breast cancer. Ann Oncol 2012; 23:743-747. [PMID: 21690231 DOI: 10.1093/annonc/mdr296] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Corrected QT (QTc) interval prolongation can induce fatal arrhythmias such as torsade de pointes. PATIENTS AND METHODS To assess the characteristics of QTc intervals and arrhythmias in women with early breast cancer who received FEC100 adjuvant chemotherapy, electrocardiograms (ECGs) were recorded before and after each chemotherapy. Associations between QTc interval prolongation and single nucleotide polymorphisms (SNPs) of potassium channel genes were also investigated. RESULTS A total of 131 ECG records were obtained in 34 patients who received 153 cycles of FEC100. QTc intervals could be measured in 127 records. There was a significant trend toward QTc interval prolongation after each treatment, persisting through four cycles of chemotherapy (P < 0.001). Median QTc interval prolongations were 13, 11, 18, and 14 ms in the first through fourth cycles of chemotherapy, respectively. QTc intervals differed significantly between cycles 1 and 4 before treatment as well as after treatment (P < 0.05). A single supraventricular premature contraction was noted in 3 (2.3%) of the 131 cycles in 2 (5.9%) of the 34 patients. There was no significant association between QTc interval prolongation and SNPs of potassium channel genes. CONCLUSION This prospective study confirmed that FEC100 is associated with significant QTc interval prolongation in women with early breast cancer.
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Affiliation(s)
- K Kitagawa
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - K Kawada
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - S Morita
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - M Inada
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - A Mitsuma
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - M Sawaki
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital
| | - S Iino
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Y Inden
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - T Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine
| | - T Imai
- Department of Breast and Endocrine Surgery, Nagoya University School of Medicine, Nagoya, Japan
| | - Y Ando
- Department of Clinical Oncology and Chemotherapy, Nagoya University Hospital.
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Hahurij ND, Kolditz DP, Bökenkamp R, Markwald RR, Schalij MJ, Poelmann RE, Gittenberger-De Groot AC, Blom NA. Accessory atrioventricular myocardial pathways in mouse heart development: substrate for supraventricular tachycardias. Pediatr Res 2011; 70:37-43. [PMID: 21399557 DOI: 10.1203/pdr.0b013e3182192bfa] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Atrioventricular reentry tachycardia (AVRT) requiring an accessory atrioventricular pathway (AP) is the most common type of arrhythmia in the perinatal period. The etiology of these arrhythmias is not fully understood as well as their capability to dissipate spontaneously in the first year of life. Temporary presence of APs during annulus fibrosus development might cause this specific type of arrhythmias. To study the presence of APs, electrophysiological recordings of ventricular activation patterns and immunohistochemical analyses with antibodies specifically against atrial myosin light chain 2 (MLC-2a), Periostin, Nkx2.5, and Connexin-43 were performed in embryonic mouse hearts ranging from 11.5 to 18.5 days post-conception (dpc). The electrophysiological recordings revealed the presence of functional APs in early (13.5-15.5 dpc) and late (16.5-18.5 dpc) postseptated stages of mouse heart development. These APs stained positive for MLC-2a and Nkx2.5 and negative for Periostin and Connexin-43. Longitudinal analyses showed that APs gradually decreased in number (p = 0.003) and size (p = 0.035) at subsequent developmental stages (13.5-18.5 dpc). Expression of periostin was observed in the developing annulus fibrosus, adjacent to APs and other locations where formation of fibrous tissue is essential. We conclude that functional APs are present during normal mouse heart development. These APs can serve as transient substrate for AVRTs in the perinatal period of development.
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Affiliation(s)
- Nathan D Hahurij
- Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, 2300 RC, The Netherlands
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Roberts R. Echocardiography: a requisite friend of the cardiac geneticist. J Am Soc Echocardiogr 2011; 24:790-1. [PMID: 21700145 DOI: 10.1016/j.echo.2011.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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van Noord C, Eijgelsheim M, Stricker BHC. Drug- and non-drug-associated QT interval prolongation. Br J Clin Pharmacol 2011; 70:16-23. [PMID: 20642543 DOI: 10.1111/j.1365-2125.2010.03660.x] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sudden cardiac death is among the most common causes of cardiovascular death in developed countries. The majority of sudden cardiac deaths are caused by acute ventricular arrhythmia following repolarization disturbances. An important risk factor for repolarization disturbances is use of QT prolonging drugs, probably partly explained by gene-drug interactions. In this review, we will summarize QT interval physiology, known risk factors for QT prolongation, including drugs and the contribution of pharmacogenetics. The long QT syndrome can be congenital or acquired. The congenital long QT syndrome is caused by mutations in ion channel subunits or regulatory protein coding genes and is a rare monogenic disorder with a mendelian pattern of inheritance. Apart from that, several common genetic variants that are associated with QT interval duration have been identified. Acquired QT prolongation is more prevalent than the congenital form. Several risk factors have been identified with use of QT prolonging drugs as the most frequent cause. Most drugs that prolong the QT interval act by blocking hERG-encoded potassium channels, although some drugs mainly modify sodium channels. Both pharmacodynamic as well as pharmacokinetic mechanisms may be responsible for QT prolongation. Pharmacokinetic interactions often involve drugs that are metabolized by cytochrome P450 enzymes. Pharmacodynamic gene-drug interactions are due to genetic variants that potentiate the QT prolonging effect of drugs. QT prolongation, often due to use of QT prolonging drugs, is a major public health issue. Recently, common genetic variants associated with QT prolongation have been identified. Few pharmacogenetic studies have been performed to establish the genetic background of acquired QT prolongation but additional studies in this newly developing field are warranted.
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Affiliation(s)
- Charlotte van Noord
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
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Piazza N, Wessells RJ. Drosophila models of cardiac disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:155-210. [PMID: 21377627 PMCID: PMC3551295 DOI: 10.1016/b978-0-12-384878-9.00005-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fruit fly Drosophila melanogaster has emerged as a useful model for cardiac diseases, both developmental abnormalities and adult functional impairment. Using the tools of both classical and molecular genetics, the study of the developing fly heart has been instrumental in identifying the major signaling events of cardiac field formation, cardiomyocyte specification, and the formation of the functioning heart tube. The larval stage of fly cardiac development has become an important model system for testing isolated preparations of living hearts for the effects of biological and pharmacological compounds on cardiac activity. Meanwhile, the recent development of effective techniques to study adult cardiac performance in the fly has opened new uses for the Drosophila model system. The fly system is now being used to study long-term alterations in adult performance caused by factors such as diet, exercise, and normal aging. The fly is a unique and valuable system for the study of such complex, long-term interactions, as it is the only invertebrate genetic model system with a working heart developmentally homologous to the vertebrate heart. Thus, the fly model combines the advantages of invertebrate genetics (such as large populations, facile molecular genetic techniques, and short lifespan) with physiological measurement techniques that allow meaningful comparisons with data from vertebrate model systems. As such, the fly model is well situated to make important contributions to the understanding of complicated interactions between environmental factors and genetics in the long-term regulation of cardiac performance.
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Affiliation(s)
- Nicole Piazza
- University of Michigan Medical School, Ann Arbor, MI, USA
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Novelli G, Predazzi IM, Mango R, Romeo F, Mehta JL. Role of genomics in cardiovascular medicine. World J Cardiol 2010; 2:428-36. [PMID: 21191544 PMCID: PMC3011138 DOI: 10.4330/wjc.v2.i12.428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Revised: 10/25/2010] [Accepted: 11/01/2010] [Indexed: 02/06/2023] Open
Abstract
As all branches of science grow and new experimental techniques become readily accessible, our knowledge of medicine is likely to increase exponentially in the coming years. Recently developed technologies have revolutionized our analytical capacities, leading to vast knowledge of many genes or genomic regions involved in the pathogenesis of congenital heart diseases, which are often associated with other genetic syndromes, coronary artery disease and non-ischemic cardiomyopathies and channelopathies. The knowledge-base of the genesis of cardiovascular diseases is likely going to be further revolutionized in this new era of genomic medicine. Here, we review the advances that have been made over the last several years in this field and discuss different genetic mechanisms that have been shown to underlie a variety of cardiovascular diseases.
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Affiliation(s)
- Giuseppe Novelli
- Giuseppe Novelli, Irene M Predazzi, Department of Biopathology and Diagnostic Imaging, Section of Medical Genetics, School of Medicine, Tor Vergata University, Via Montpellier 1, 00133 Rome, Italy
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Zamorano-León JJ, Alonso-Orgaz S, Moreno J, Cinza R, García-Torrent MJ, Pérez-Castellano N, Pérez-Villacastín J, Macaya C, López-Farré AJ. Novel mutation (H402R) in the S1 domain of KCNH2-encoded gene associated with long QT syndrome in a Spanish family. Int J Cardiol 2010; 142:206-8. [DOI: 10.1016/j.ijcard.2008.11.166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 11/29/2008] [Indexed: 11/26/2022]
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Eagle KA, Ginsburg GS, Musunuru K, Aird WC, Balaban RS, Bennett SK, Blumenthal RS, Coughlin SR, Davidson KW, Frohlich ED, Greenland P, Jarvik GP, Libby P, Pepine CJ, Ruskin JN, Stillman AE, Van Eyk JE, Tolunay HE, McDonald CL, Smith SC. Identifying patients at high risk of a cardiovascular event in the near future: current status and future directions: report of a national heart, lung, and blood institute working group. Circulation 2010; 121:1447-54. [PMID: 20351302 DOI: 10.1161/circulationaha.109.904029] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kim A Eagle
- University of Michigan Cardiovascular Center, Ann Arbor, MI 48109-5852, USA.
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Albert CM, MacRae CA, Chasman DI, VanDenburgh M, Buring JE, Manson JE, Cook NR, Newton-Cheh C. Common variants in cardiac ion channel genes are associated with sudden cardiac death. Circ Arrhythm Electrophysiol 2010; 3:222-9. [PMID: 20400777 DOI: 10.1161/circep.110.944934] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Rare variants in cardiac ion channel genes are associated with sudden cardiac death in rare primary arrhythmic syndromes; however, it is unknown whether common variation in these same genes may contribute to sudden cardiac death risk at the population level. METHODS AND RESULTS We examined the association between 147 single nucleotide polymorphisms (SNPs) (137 tag, 5 noncoding SNPs associated with QT interval duration, and 5 nonsynonymous SNPs) in 5 cardiac ion channel genes, KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2, and sudden and/or arrhythmic death in a combined nested case-control analysis among 516 cases and 1522 matched control subjects of European ancestry enrolled in 6 prospective cohort studies. After accounting for multiple testing, 2 SNPs (rs2283222 located in intron 11 in KCNQ1 and rs11720524 located in intron 1 in SCN5A) remained significantly associated with sudden/arrhythmic death (false discovery rate=0.01 and 0.03, respectively). Each increasing copy of the major T-allele of rs2283222 or the major C-allele of rs1172052 was associated with an odds ratio of 1.36 (95% confidence interval, 1.16 to 1.60; P=0.0002) and 1.30 (95% confidence interval, 1.12 to 1.51; P=0.0005), respectively. Control for cardiovascular risk factors and/or limiting the analysis to definite sudden cardiac death did not significantly alter these relationships. CONCLUSION In this combined analysis of 6 prospective cohort studies, 2 common intronic variants in KCNQ1 and SCN5A were associated with sudden cardiac death in individuals of European ancestry. Further study in other populations and investigation into the functional abnormalities associated with noncoding variation in these genes may lead to important insights into predisposition to lethal arrhythmias.
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Affiliation(s)
- Christine M Albert
- Center for Arrhythmia Prevention, Division of Preventive Medicine, Cardiovascular Division, Channing Laboratory, and Division of Aging, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115-1204, USA.
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The genome-wide association study--a new era for common polygenic disorders. J Cardiovasc Transl Res 2010; 3:173-82. [PMID: 20560037 DOI: 10.1007/s12265-010-9178-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 03/01/2010] [Indexed: 12/22/2022]
Abstract
This review covers the advances made in the last decade utilizing the high-density single-nucleotide microarrays to screen the entire human genome for genetic risk variants and outlines future strategies to draw deeper into the human genetic front. The sequence of the human genome provides the blueprint for life, while its variation provides the spice of life. Approximately 99.5% of the human genome DNA sequence is identical among humans with 0.5% of the genome sequence (15 million bps) accounting for all individual differences including susceptibility for disease. The new technology of the computerized chip array containing up to millions of SNPs as DNA markers makes possible genome-wide association studies to detect genetic predisposition to common polygenic disorders such as coronary artery disease (CAD). The sample sizes required for these studies are massive and large; worldwide consortiums such as CARDIoGRAM have been formed to accommodate this requirement. The progress has been remarkable with the identification of 9p21 followed by several others within the past 2 years. It is expected that most of the common variants (minor allele frequency, MAF >5%) will be identified for CAD within the next 2 to 3 years. Rare variants (MAF <5%) will require direct sequencing which will be delayed somewhat. The ultimate objective for the future is the sequencing and functional analysis of the causative polymorphisms. This will require a new approach involving several disciplines, namely, bioinformatics, high-throughput cell expression, and animal models.
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Heart rhythm genomic fabric in hypoxia. Biochem Biophys Res Commun 2009; 391:1769-74. [PMID: 20044980 DOI: 10.1016/j.bbrc.2009.12.151] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 12/24/2009] [Indexed: 11/23/2022]
Abstract
The molecular mechanisms by which chronic hypoxia, whether constant (CCH) or intermittent (CIH), alters the heart rhythm are still under debate. Expression level, control, maturational profile and intercoordination of 54 genes encoding heart rhythm determinants (HRDs) were analyzed in 36 mice subjected for 1, 2 or 4 weeks of their early life to normal atmospheric conditions or to CCH or CIH. Our analysis revealed a complex network of genes encoding various heart rate, inotropy and development controllers, receptors, ion channels and transporters, ankyrins, epigenetic modulators and intercalated disc components (adherens, cadherins, catenins, desmosomal, gap and tight junction proteins). The network is remodeled during maturation and substantially and differently altered by CIH and CCH. Gene Prominence Analysis that ranks the genes according to their expression stability and networking within functional gene webs, confirmed the HRD status of certain epigenetic modulators and components of the intercalated discs not yet associated with arrhythmia.
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Pretorius L, Du XJ, Woodcock EA, Kiriazis H, Lin RCY, Marasco S, Medcalf RL, Ming Z, Head GA, Tan JW, Cemerlang N, Sadoshima J, Shioi T, Izumo S, Lukoshkova EV, Dart AM, Jennings GL, McMullen JR. Reduced phosphoinositide 3-kinase (p110alpha) activation increases the susceptibility to atrial fibrillation. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:998-1009. [PMID: 19679877 DOI: 10.2353/ajpath.2009.090126] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia presenting at cardiology departments. A limited understanding of the molecular mechanisms responsible for the development of AF has hindered treatment strategies. The purpose of this study was to assess whether reduced activation of phosphoinositide 3-kinase (PI3K, p110alpha) makes the compromised heart susceptible to AF. Risk factors for AF, including aging, obesity, and diabetes, have been associated with insulin resistance that leads to depressed/defective PI3K signaling. However, to date, there has been no link between PI3K(p110alpha) and AF. To address this question, we crossed a cardiac-specific transgenic mouse model of dilated cardiomyopathy (DCM) with a cardiac-specific transgenic mouse expressing a dominant negative mutant of PI3K (dnPI3K; reduces PI3K activity). Adult ( approximately 4.5 months) double-transgenic (dnPI3K-DCM), single-transgenic (DCM-Tg, dnPI3K-Tg), and nontransgenic mice were subjected to morphological, functional/ECG, microarray, and biochemical analyses. dnPI3K-DCM mice developed AF and had depressed cardiac function as well as greater atrial enlargement and fibrosis than DCM-Tg mice. AF was not detected in other groups. Aged DCM-Tg mice ( approximately 15 months) with a similar phenotype to dnPI3K-DCM mice (4.5 months) did not develop AF, suggesting loss of PI3K activity directly contributed to the AF phenotype. Furthermore, increasing PI3K activity reduced atrial fibrosis and improved cardiac conduction in DCM-Tg mice. Finally, in atrial appendages from patients with AF, PI3K activation was lower compared with tissue from patients in sinus rhythm. These results suggest a link between PI3K(p110alpha) and AF.
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Affiliation(s)
- Lynette Pretorius
- Baker IDI Heart and Diabetes Institute, St. Kilda Rd. Central, Melbourne, Victoria 8008, Australia
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Campuzano O, Sarquella-Brugada G, Brugada R, Brugada P, Brugada J. Cardiovascular translational medicine (IV): The genetic basis of malignant arrhythmias and cardiomyopathies. Rev Esp Cardiol 2009; 62:422-36. [PMID: 19401127 DOI: 10.1016/s1885-5857(09)71669-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The remarkable advances that have taken place in biomedicine over the past 50 years have resulted in dramatic improvements in the prevention, diagnosis and treatment of many diseases. Although cardiology has adopted these advances at a relatively slow pace, today it is fully immersed in this revolution and has become one of the most innovative medical specialties. Research is continuing to give rise to new developments in genetics and molecular biology that lead, almost daily, to innovative ways of preventing, diagnosing and treating the most severe forms of heart disease. Consequently, it is essential that clinical cardiologists have some basic knowledge of genetics and molecular biology as these disciplines are having an increasing influence on clinical practice.
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Affiliation(s)
- Oscar Campuzano
- Centre de Genètica Cardiovascular, Universitat de Girona, Girona 08036, Spain
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Viswanathan MN, Page RL. Pharmacological therapy for atrial fibrillation: current options and new agents. Expert Opin Investig Drugs 2009; 18:417-31. [PMID: 19278302 DOI: 10.1517/13543780902773410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Atrial fibrillation is the most commonly encountered cardiac arrhythmia and is directly or indirectly responsible for considerable mortality, morbidity and health care burden. The available medical therapy is limited by marginal efficacy, end-organ toxicity, as well as the potential for undesired ventricular proarrhythmia. Elucidation of the potential mechanisms that underlie the development of atrial fibrillation may provide new targets for drugs that circumvent the problems associated with current medical options. This review focuses on the current and potential future pharmacological agents directed at rhythm control and maintenance of sinus rhythm.
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Affiliation(s)
- Mohan N Viswanathan
- University of Washington, Division of Cardiology/Cardiac Electrophysiology, Seattle, WA 98195-6422, USA.
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Remme CA, Scicluna BP, Verkerk AO, Amin AS, van Brunschot S, Beekman L, Deneer VHM, Chevalier C, Oyama F, Miyazaki H, Nukina N, Wilders R, Escande D, Houlgatte R, Wilde AAM, Tan HL, Veldkamp MW, de Bakker JMT, Bezzina CR. Genetically determined differences in sodium current characteristics modulate conduction disease severity in mice with cardiac sodium channelopathy. Circ Res 2009; 104:1283-92. [PMID: 19407241 DOI: 10.1161/circresaha.109.194423] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Conduction slowing of the electric impulse that drives the heartbeat may evoke lethal cardiac arrhythmias. Mutations in SCN5A, which encodes the pore-forming cardiac sodium channel alpha subunit, are associated with familial arrhythmia syndromes based on conduction slowing. However, disease severity among mutation carriers is highly variable. We hypothesized that genetic modifiers underlie the variability in conduction slowing and disease severity. With the aim of identifying such modifiers, we studied the Scn5a(1798insD/+) mutation in 2 distinct mouse strains, FVB/N and 129P2. In 129P2 mice, the mutation resulted in more severe conduction slowing particularly in the right ventricle (RV) compared to FVB/N. Pan-genomic mRNA expression profiling in the 2 mouse strains uncovered a drastic reduction in mRNA encoding the sodium channel auxiliary subunit beta4 (Scn4b) in 129P2 mice compared to FVB/N. This corresponded to low to undetectable beta4 protein levels in 129P2 ventricular tissue, whereas abundant beta4 protein was detected in FVB/N. Sodium current measurements in isolated myocytes from the 2 mouse strains indicated that sodium channel activation in myocytes from 129P2 mice occurred at more positive potentials compared to FVB/N. Using computer simulations, this difference in activation kinetics was predicted to explain the observed differences in conduction disease severity between the 2 strains. In conclusion, genetically determined differences in sodium current characteristics on the myocyte level modulate disease severity in cardiac sodium channelopathies. In particular, the sodium channel subunit beta4 (SCN4B) may constitute a potential genetic modifier of conduction and cardiac sodium channel disease.
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Affiliation(s)
- Carol Ann Remme
- Heart Failure Research Center, Department of Experimental Cardiology, Academic Medical Center, University of Amsterdam, Room K2-110, PO Box 22700, 1100 DE Amsterdam, The Netherlands.
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Abstract
PURPOSE OF REVIEW To review the evidence supporting genetic predisposition to coronary artery disease (CAD). Secondly, to elucidate the barriers precluding the identification of genes responsible for CAD. Thirdly, to indicate the new technology now available to overcome these barriers and summarize current progress. RECENT FINDINGS Evidence strongly supports that 50% of susceptibility to CAD is genetic. Prevention of CAD requires comprehensive genetic and risk factor modification. Technology to perform genome-wide association studies became available in 2005, namely, the microarrays with 500,000 and 1 million single nucleotide polymorphisms as DNA markers for high-throughput genotyping to determine gene frequencies in large datasets of cases and controls. The first genetic variant, 9p21, for CAD was identified in the Ottawa Heart Genomic study. This is not only a genetic risk factor but also independent of other known risk factors for CAD. 9p21 was subsequently confirmed as a risk variant in several other independent studies involving 64 000 Caucasians. 9p21 increases the risk of CAD by 40% and 20% in heterozygous or homozygous forms respectively. It occurs in 75% of Caucasians, and has recently been confirmed in several other ethnic groups. SUMMARY Thus, identification of predisposition to CAD is well underway with genome-wide association studies and the first common genetic risk variant, 9p21, has been identified.
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van der Roest WP, Pennings JM, Bakker M, van den Berg MP, van Tintelen JP. Family letters are an effective way to inform relatives about inherited cardiac disease. Am J Med Genet A 2009; 149A:357-63. [DOI: 10.1002/ajmg.a.32672] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Abstract
Arrhythmias arise from a complex interaction between structural changes in the myocardium and changes in cellular electrophysiology. Electrophysiological balance requires precise control of sarcolemmal ion channels and exchangers, many of which are regulated by phospholipid, phosphatidylinositol(4,5)bisphosphate. Phosphatidylinositol(4,5)bisphosphate is the immediate precursor of inositol(1,4,5)trisphosphate, a regulator of intracellular Ca2+ signalling and, therefore, a potential contributor to arrhythmogenesis by altering Ca2+ homeostasis. The aim of the present review is to outline current evidence that this signalling pathway can be a player in the initiation or maintenance of arrhythmias.
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Affiliation(s)
- Elizabeth A Woodcock
- Molecular Cardiology Laboratory, Baker IDI Heart and Diabetes Institute, PO Box 6492, St Kilda Road Central, Melbourne, 8008 Victoria, Australia.
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Schulze-Bahr E. Susceptibility genes & modifiers for cardiac arrhythmias. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2008; 98:289-300. [DOI: 10.1016/j.pbiomolbio.2009.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Lin MT, Wu MH, Chang CC, Chiu SN, Thériault O, Huang H, Christé G, Ficker E, Chahine M. In utero onset of long QT syndrome with atrioventricular block and spontaneous or lidocaine-induced ventricular tachycardia: compound effects of hERG pore region mutation and SCN5A N-terminus variant. Heart Rhythm 2008; 5:1567-74. [PMID: 18848812 DOI: 10.1016/j.hrthm.2008.08.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 08/08/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND Mexiletine may protect patients with long QT syndrome (LQTS) type 3 from arrhythmias. However, we found an unusual in utero presentation of intermittent atrioventricular block and ventricular tachycardia (spontaneous or lidocaine-induced) in a fetus and his sibling with LQTS. OBJECTIVE The purpose of this study was to investigate the underlying channelopathy and functional alteration. METHODS Mutations were searched in KCNQ1, HERG, KCNE1, KCNE2, and SCN5A genes. In expressed mutants, whole-cell voltage clamp defined the electrophysiologic properties. RESULTS Novel missense mutations involving hERG (F627L) at the pore region and SCN5A (R43Q) at the N-terminus were found in the proband and in family members with prolonged QT interval. In oocytes injected with mRNA encoding hERG/ F627L, almost zero K(+) currents were elicited. In coinjected oocytes, the currents were decreased to half. In tsA201 cells transfected with SCN5A/R43Q, although the baseline kinetics of the Na current were similar to wild type, lidocaine caused a unique hyperpolarizing shift of the activation and increased the availability of Na currents at resting voltages. Window currents were enhanced due to a right shift of steady-state inactivation. These electrophysiologic alterations after lidocaine may lead to the development of ventricular tachycardia. CONCLUSION We identified a novel hERG/F627L mutation that results in LQTS with fetal onset of atrioventricular block and ventricular tachycardia. A coexisting SCN5A/R43Q variant, although it per se does not prolong repolarization, contributes to the development of ventricular tachyarrhythmias after lidocaine. Patients with such latent lidocaine-induced phenotype who are given lidocaine or mexiletine may be at risk.
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Affiliation(s)
- Ming-Tai Lin
- Department of Pediatrics, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
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The human genome and prospects for management of cardiovascular disease. Can J Cardiol 2008. [DOI: 10.1016/s0828-282x(08)71031-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
Background—
Fetal and neonatal atrioventricular (AV) reentrant tachycardias can be life-threatening but resolve in most cases during the first year of life. The transient presence of accessory AV myocardial connections during annulus fibrosus development may explain this phenomenon.
Methods and Results—
A total of 45 human embryonic, fetal, and neonatal sectioned hearts (4 to 36 weeks of development) were studied immunohistochemically. Accessory myocardial AV connections were quantified and categorized according to their specific location, and 3D reconstructions were made. Between 4 and 6 weeks of development, the atrial and ventricular myocardium was continuous at the primitive AV canal. At 6 to 10 weeks, numerous accessory myocardial AV connections were identified in the left (45%), right (35%), and septal (20%) regions of the AV junction. Most right-sided accessory connections comprised distinct myocardial strands, whereas left-sided connections consisted of larger myocardial continuities. At 10 to 20 weeks, all accessory AV connections comprised discrete myocardial strands and gradually decreased in number. The majority of accessory connections were located in the right AV junction (67%), predominantly in the lateral aspect (45%). Seventeen percent of the accessory connections were observed in the left AV junction, and 16% were observed in the septal region. 3D reconstructions of the developing AV nodal area at these stages demonstrated multiple AV node–related accessory connections. From 20 weeks until birth, and in neonatal hearts, no further accessory myocardial AV connections were observed.
Conclusions—
Isolation of the AV junction is a gradual and ongoing process, and right lateral accessory myocardial AV connections in particular are commonly found at later stages of normal human cardiac development. These transitory accessory connections may act as substrate for AV reentrant tachycardias in fetuses or neonates.
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Hershberger RE. Cardiovascular genetic medicine: evolving concepts, rationale, and implementation. J Cardiovasc Transl Res 2008; 1:137-43. [PMID: 20559908 DOI: 10.1007/s12265-008-9031-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
Cardiovascular genetic medicine is devoted to the identification and understanding of cardiac conditions resulting from genetic and genomic mechanisms and to the development and validation of diagnostic and treatment algorithms and guidelines. Cardiovascular genetic medicine clinics now provide expert cardiovascular subspecialty care, genetic counseling and clinical genetic testing, and will eventually provide disease-specific gene or genetic therapies. Currently, the most tractable diagnoses for cardiovascular genetic medicine are the single-gene disorders: the cardiomyopathies, the channelopathies, and others. The recent explosion of genetic knowledge within the single-gene disorders and consequent rapid proliferation of genetic testing enables far greater numbers of individuals to directly benefit from this progress. A compelling rationale exists for this approach: cardiovascular single-gene diseases commonly present with life-threatening events (e.g., sudden cardiac death, heart failure, stroke, etc.), but identification, evaluation, and treatment of individuals with presymptomatic genetic risk has the promise to prevent or ameliorate cardiovascular morbidity and mortality. Cardiovascular genetic medicine programs also anchor training and research, thereby enabling the next generation of academic specialists in cardiovascular genetic medicine to continue to improve cardiovascular health.
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Affiliation(s)
- Ray E Hershberger
- Cardiovascular Division, Clinical Research Building, Miller School of Medicine, University of Miami, Miami, FL 33101, USA.
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Affiliation(s)
- Henry Greenberg
- Division of Cardiology, St. Luke's Roosevelt Hospital, New York, NY 10019, USA.
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Roberts R, Stewart AFR, Wells GA, Williams KA, Kavaslar N, McPherson R. Identifying genes for coronary artery disease: An idea whose time has come. Can J Cardiol 2008; 23 Suppl A:7A-15A. [PMID: 17668082 PMCID: PMC2787000 DOI: 10.1016/s0828-282x(07)71000-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Coronary artery disease (CAD) remains the number one killer in the western world. Genetics accounts for greater than 50% of the risk for CAD. Genetic screening and early prevention in individuals identified as being at increased risk could dramatically reduce the prevalence of CAD, thus necessitating the identification of genes predisposing to CAD. Studies of genes identified by the candidate gene approach have not been replicated due, in part, to inadequate sample size. Genome-wide scan association studies have been limited by the use of thousands of markers rather than the hundreds of thousands required, and by the use of hundreds of individuals rather than the thousands required. Replication of positive findings in an independent population is essential. To detect a minor allele frequency of 5% or greater with an odds ratio for risk of 1.3 or greater and 90% power, an estimated 14,000 (9000 affected and 5000 control) subjects are required. METHODS The Affymetrix GeneChip Human Mapping 500K Array Set (Affymetrix Inc, USA) provides a marker every 6000 base pairs as required, and is being used to genotype 1000 cases of premature CAD and 1000 normal subjects, followed by replication in 8000 affected individuals and 4000 control subjects. The phenotype is confirmed or excluded by coronary arteriograms by catheterization or multislice computed tomography. RESULTS Since 2005, more than 800 million genotypes have been performed and analyses performed on 500 control subjects and 500 affected individuals. Several thousand significant single nucleotide polymorphisms and 130 clusters associated with CAD have been identified. CONCLUSIONS This is the first genome-wide scan using the 500,000 marker set in a case-control association study for CAD genes. Several genes associated with CAD appear promising.
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Larson MG, Atwood LD, Benjamin EJ, Cupples LA, D'Agostino RB, Fox CS, Govindaraju DR, Guo CY, Heard-Costa NL, Hwang SJ, Murabito JM, Newton-Cheh C, O'Donnell CJ, Seshadri S, Vasan RS, Wang TJ, Wolf PA, Levy D. Framingham Heart Study 100K project: genome-wide associations for cardiovascular disease outcomes. BMC MEDICAL GENETICS 2007; 8 Suppl 1:S5. [PMID: 17903304 PMCID: PMC1995607 DOI: 10.1186/1471-2350-8-s1-s5] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Cardiovascular disease (CVD) and its most common manifestations--including coronary heart disease (CHD), stroke, heart failure (HF), and atrial fibrillation (AF)--are major causes of morbidity and mortality. In many industrialized countries, cardiovascular disease (CVD) claims more lives each year than any other disease. Heart disease and stroke are the first and third leading causes of death in the United States. Prior investigations have reported several single gene variants associated with CHD, stroke, HF, and AF. We report a community-based genome-wide association study of major CVD outcomes. METHODS In 1345 Framingham Heart Study participants from the largest 310 pedigrees (54% women, mean age 33 years at entry), we analyzed associations of 70,987 qualifying SNPs (Affymetrix 100K GeneChip) to four major CVD outcomes: major atherosclerotic CVD (n = 142; myocardial infarction, stroke, CHD death), major CHD (n = 118; myocardial infarction, CHD death), AF (n = 151), and HF (n = 73). Participants free of the condition at entry were included in proportional hazards models. We analyzed model-based deviance residuals using generalized estimating equations to test associations between SNP genotypes and traits in additive genetic models restricted to autosomal SNPs with minor allele frequency > or =0.10, genotype call rate > or =0.80, and Hardy-Weinberg equilibrium p-value > or = 0.001. RESULTS Six associations yielded p < 10(-5). The lowest p-values for each CVD trait were as follows: major CVD, rs499818, p = 6.6 x 10(-6); major CHD, rs2549513, p = 9.7 x 10(-6); AF, rs958546, p = 4.8 x 10(-6); HF: rs740363, p = 8.8 x 10(-6). Of note, we found associations of a 13 Kb region on chromosome 9p21 with major CVD (p 1.7-1.9 x 10(-5)) and major CHD (p 2.5-3.5 x 10(-4)) that confirm associations with CHD in two recently reported genome-wide association studies. Also, rs10501920 in CNTN5 was associated with AF (p = 9.4 x 10(-6)) and HF (p = 1.2 x 10(-4)). Complete results for these phenotypes can be found at the dbgap website http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite. CONCLUSION No association attained genome-wide significance, but several intriguing findings emerged. Notably, we replicated associations of chromosome 9p21 with major CVD. Additional studies are needed to validate these results. Finding genetic variants associated with CVD may point to novel disease pathways and identify potential targeted preventive therapies.
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Affiliation(s)
- Martin G Larson
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Larry D Atwood
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Emelia J Benjamin
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - L Adrienne Cupples
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - Ralph B D'Agostino
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Caroline S Fox
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
| | - Diddahally R Govindaraju
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Chao-Yu Guo
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Nancy L Heard-Costa
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Shih-Jen Hwang
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
| | - Joanne M Murabito
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Section of General Internal Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Christopher Newton-Cheh
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Christopher J O'Donnell
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Sudha Seshadri
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Ramachandran S Vasan
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Thomas J Wang
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Philip A Wolf
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
- Boston University School of Medicine, Boston, MA, USA
| | - Daniel Levy
- The National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, MA, USA
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Drug-induced long QT syndrome: molecular mechanisms for congenital and acquired QT prolongation. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.ddmec.2008.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Koo SH, Teo WS, Ching CK, Chan SH, Lee EJD. Mutation Screening in KCNQ1, HERG, KCNE1, KCNE2 and SCN5A Genes in a Long QT Syndrome Family. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2007. [DOI: 10.47102/annals-acadmedsg.v36n6p394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Introduction: Long QT syndrome (LQTS), an inherited cardiac arrhythmia, is a disorder of ventricular repolarisation characterised by electrocardiographic abnormalities and the onset of torsades de pointes leading to syncope and sudden death. Genetic polymorphisms in 5 wellcharacterised cardiac ion channel genes have been identified to be responsible for the disorder. The aim of this study is to identify disease-causing mutations in these candidate genes in a LQTS family.
Materials and Methods: The present study systematically screens the coding region of the LQTS-associated genes (KCNQ1, HERG, KCNE1, KCNE2 and SCN5A) for mutations using DNA sequencing analysis.
Results: The mutational analysis revealed 7 synonymous and 2 nonsynonymous polymorphisms in the 5 ion channel genes screened.
Conclusion: We did not identify any clear identifiable genetic marker causative of LQTS, suggesting the existence of LQTSassociated genes awaiting discovery.
Key words: Arrhythmia, Ion channels, Long QT syndrome
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44
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Beanlands R, Roberts R. Positron molecular imaging, an in vivo glimpse of the genome. J Mol Cell Cardiol 2007; 43:11-4. [PMID: 17544439 DOI: 10.1016/j.yjmcc.2007.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 05/03/2007] [Indexed: 12/01/2022]
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45
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Charron P, Genest M, Richard P, Komajda M, Pochmalicki G. A familial form of conduction defect related to a mutation in the PRKAG2 gene. Europace 2007; 9:597-600. [PMID: 17483151 DOI: 10.1093/europace/eum071] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We describe four members of the same family with a very similar ECG pattern characterized by conduction defects (right bundle branch block, frequent left anterior hemiblock, atrial hypertrophy, and sometimes severe nodal dysfunction) contrasting with a short PR interval. Significant clinical events were reported only after 60 years of age. A mutation in the gamma2 subunit of the AMP activated protein kinase gene (PRKAG2) was identified in the four members of the family, with an autosomal dominant inheritance. The phenotype observed in this family appears different from that previously described as associated with this gene as neither left ventricular hypertrophy nor Wolff-Parkinson-White syndrome was present. These findings extend the phenotype associated with the PRKAG2 gene and emphasize an additional cause of familial conduction defect.
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Affiliation(s)
- Philippe Charron
- Université Pierre et Marie Curie-Paris 6, Inserm UMR621, AP-HP, Hôpital Pitié-Salpêtrière, Département de Cardiologie, Paris, France.
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46
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Molekulární kardiologie dnes. COR ET VASA 2007. [DOI: 10.33678/cor.2007.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Ocorr K, Reeves NL, Wessells RJ, Fink M, Chen HSV, Akasaka T, Yasuda S, Metzger JM, Giles W, Posakony JW, Bodmer R. KCNQ potassium channel mutations cause cardiac arrhythmias in Drosophila that mimic the effects of aging. Proc Natl Acad Sci U S A 2007; 104:3943-8. [PMID: 17360457 PMCID: PMC1820688 DOI: 10.1073/pnas.0609278104] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Indexed: 12/13/2022] Open
Abstract
Population profiles of industrialized countries show dramatic increases in cardiovascular disease with age, but the molecular and genetic basis of disease progression has been difficult to study because of the lack of suitable model systems. Our studies of Drosophila show a markedly elevated incidence of cardiac dysfunction and arrhythmias in aging fruit fly hearts and a concomitant decrease in the expression of the Drosophila homolog of human KCNQ1-encoded K(+) channel alpha subunits. In humans, this channel is involved in myocardial repolarization, and alterations in the function of this channel are associated with an increased risk for Torsades des Pointes arrhythmias and sudden death. Hearts from young KCNQ1 mutant fruit flies exhibit prolonged contractions and fibrillations reminiscent of Torsades des Pointes arrhythmias, and they exhibit severely increased susceptibility to pacing-induced cardiac dysfunction at young ages, characteristics that are observed only at advanced ages in WT flies. The fibrillations observed in mutant flies correlate with delayed relaxation of the myocardium, as revealed by increases in the duration of phasic contractions, extracellular field potentials, and in the baseline diastolic tension. These results suggest that K(+) currents, mediated by a KCNQ channel, contribute to the repolarization reserve of fly hearts, ensuring normal excitation-contraction coupling and rhythmical contraction. That arrhythmias in both WT and KCNQ1 mutants become worse as flies age suggests that additional factors are also involved.
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Affiliation(s)
- Karen Ocorr
- *Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, CA 92037
| | - Nick L. Reeves
- Division of Biological Sciences/Section of Cell and Developmental Biology and
| | - Robert J. Wessells
- *Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, CA 92037
| | | | - H.-S. Vincent Chen
- *Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, CA 92037
- **Cardiology, University of California at San Diego, La Jolla, CA 92093-0349; and
| | - Takeshi Akasaka
- *Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, CA 92037
| | - Soichiro Yasuda
- Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109
| | - Joseph M. Metzger
- Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109
| | | | - James W. Posakony
- Division of Biological Sciences/Section of Cell and Developmental Biology and
| | - Rolf Bodmer
- *Center for Neuroscience and Aging, Burnham Institute for Medical Research, La Jolla, CA 92037
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48
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Lewalter T, Schwab JO, Nickenig G. [Ventricular tachycardia. Diagnostic spectrum and therapeutic measures]. Internist (Berl) 2007; 47:1001-4, 1006-8, 1010-2. [PMID: 16969671 DOI: 10.1007/s00108-006-1708-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The origin of ventricular tachycardia lies in the ventricular tissue and includes a variety of symptoms such as monomorphic and polymorphic ventricular tachyarrhythmia (VT), ventricular flutter and ventricular fibrillation. Due to transitions of one form of VT to another, any form of VT incurs in principal the risk of cardiac failure. Apart from different electrophysiologic mechanisms such as reentry or triggered activity, any occurrence of VT has to be considered in an individual context: VT can be caused by structural heart disease such as coronary artery disease or dilative cardiomyopathy, or primary electrical disease such as long or short QT syndromes or can even occur without any detectable cause (idiopathic VT). Correct identification of the underlying cause of the arrhythmia is essential for the prognosis, differential therapy and long-term treatment of patients.
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Affiliation(s)
- T Lewalter
- Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn, Germany.
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Abstract
Atrial fibrillation is the most common cardiac arrhythmia and is a major cause of cardiovascular morbidity and mortality in the Western world. Present pharmacological options are limited by inefficacy, proarrhythmia and end-organ toxicity. Enhanced understanding of the underlying causes of this pleotropic entity may allow the creation of targeted drugs that avoid the pitfalls of current options. This review concentrates on both the classical and novel pharmacological therapies aimed at maintaining sinus rhythm.
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Affiliation(s)
- Kristen K Patton
- University of Washington Medical Center, Division of Cardiology, 1959 NE Pacific Street, Box 356422, Seattle, WA 98122, USA.
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50
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Roberts R, Stewart AF. Personalized genomic medicine: a future prerequisite for the prevention of coronary artery disease. ACTA ACUST UNITED AC 2007; 4:222-7. [PMID: 16894262 DOI: 10.1111/j.1541-9215.2006.05537.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Within the next 10-15 years, medicine will be personalized in large part on the basis of the individual's genomic variants. Coronary artery disease remains the number one cause of morbidity and mortality in the Western world and is predicted to become the number one cause worldwide by 2010. It has been stated that treating the risk factors of coronary artery disease has made it a preventable disease that should be eliminated in the 21st century. It is postulated that about 50% of susceptibility to coronary artery disease is genetic, involving known and occult risk factors. Thus, comprehensive prevention will require identification of genetic susceptibility. The recent technology of a chip with 500,000 DNA markers makes genome-wide scanning to identify the genes contributing to coronary artery disease possible. Multislice CT will provide the high-throughput coronary arteriograms required for this research and for prevention in asymptomatic individuals with a family history of heart disease.
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Affiliation(s)
- Robert Roberts
- Division of Cardiology, Univeristy of Ottawa Heart Institute, Ottawa, Ontario, Canada.
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