251
|
Veronese C, Bagattin A, Rampazzo A, Danieli GA. Gene symbol: RYR2. Disease: Effort-induced polymorphic ventricular arrhythmias. Hum Genet 2004; 114:404. [PMID: 15046070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- C Veronese
- Human Genetics Lab, Dept. of Biology, University of Padua, Italy.
| | | | | | | |
Collapse
|
252
|
Abstract
BACKGROUND Although Brugada syndrome revolves around reduced net depolarizing force, the electrophysiological mechanisms of its defining features (right precordial ST-segment elevation and ventricular tachyarrhythmias) remain unresolved. Two proposed mechanisms are (1) right ventricular (RV) conduction delay and (2) selective and significant RV subepicardial action potential shortening. Both mechanisms must cause disparate contractile changes: delay in RV contraction and reduction of contractile force, respectively. We aimed to establish the electrophysiological mechanism of Brugada syndrome by studying the timing and force of RV contraction. METHODS AND RESULTS Using tissue Doppler echocardiography, we studied how these contractile variables change on induction of the characteristic ST-segment changes of Brugada syndrome by flecainide challenge. Accordingly, we studied patients in whom flecainide induced these changes (inducible) and those in whom these changes were not induced (control). We found that (1) the occurrence of a positive response (coved-type ST elevation) after flecainide coincides with delay in the onset of contraction between the RV and left ventricle (LV); (2) the extent of contraction delay between RV and LV correlates with the magnitude of ST elevation; and (3) RV ejection time (duration of RV ejection phase) shortens as the Brugada ECG pattern emerges. CONCLUSIONS These results indicate that both proposed mechanisms of Brugada syndrome may be operative.
Collapse
Affiliation(s)
- Raymond Tukkie
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
253
|
Veronese C, Bagattin A, Rampazzo A, Danieli GA. Gene symbol: RYR2. Disease: Effort-induced polymorphic ventricular arrhythmias. Hum Genet 2004; 114:405. [PMID: 15046067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- C Veronese
- Human Genetics Lab, Dept. of Biology, University of Padua, Italy.
| | | | | | | |
Collapse
|
254
|
Bagattin A, Veronese C, Rampazzo A, Danieli GA. Gene symbol: RYR2. Disease: Effort-induced polymorphic ventricular arrhythmias. Hum Genet 2004; 114:405. [PMID: 15046073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- A Bagattin
- Human Genetics Lab, Dept. of Biology, University of Padua, Italy.
| | | | | | | |
Collapse
|
255
|
De Rosa G, Delogu AB, Piastra M, Chiaretti A, Bloise R, Priori SG. Catecholaminergic polymorphic ventricular tachycardia: successful emergency treatment with intravenous propranolol. Pediatr Emerg Care 2004; 20:175-177. [PMID: 15094576 DOI: 10.1097/01.pec.0000117927.65522.7a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (VT) is a rare arrhythmogenic disorder, which may cause sudden death and whose relationships with mutations in cardiac ryanodine receptor gene have been recently established. The present article reports a catecholaminergic polymorphic VT case of a 9-year-old girl, without any previous history of syncope, who has been found unconscious while playing and referred comatose to pediatric intensive care unit. The electrocardiogram pattern showed runs of bidirectional and polymorphic VT degenerating into ventricular fibrillation, without QT interval abnormalities. Various attempts of cardioversion, lidocaine, and magnesium sulfate intravenous infusions were only partially effective. Owing to catecholaminergic polymorphic VT highly suggesting electrocardiogram pattern, intravenous propranolol was administered, achieving immediate VT interruption. Long-term nadolol therapy effectively prevented further arrhythmias, with no relapses up to 10 months later; a good neurologic recovery was also obtained. Genetic evaluation revealed in this patient-but not in relatives-a mutation in ryanodine receptor gene on chromosome 1.
Collapse
Affiliation(s)
- Gabriella De Rosa
- *Pediatric Cardiology, Catholic University Medical School, Rome, Italy; †Pediatric Intensive Care Unit, Catholic University Medical School, Rome, Italy; ‡Molecular Cardiology, IRCCS Fondazione "Salvatore Maugeri," University of Pavia, Pavia, Italy
| | | | | | | | | | | |
Collapse
|
256
|
Bagattin A, Bauce B, Rampazzo A, Tiso N, Nava A, Danieli GA. Gene symbol: RYR2. Disease: Effort-induced polymorphic ventricular arrhythmias. Hum Genet 2004; 114:406. [PMID: 15046079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- A Bagattin
- Department of Biology, University of Padua, Italy.
| | | | | | | | | | | |
Collapse
|
257
|
van Rijen HVM, Eckardt D, Degen J, Theis M, Ott T, Willecke K, Jongsma HJ, Opthof T, de Bakker JMT. Slow conduction and enhanced anisotropy increase the propensity for ventricular tachyarrhythmias in adult mice with induced deletion of connexin43. Circulation 2004; 109:1048-55. [PMID: 14967725 DOI: 10.1161/01.cir.0000117402.70689.75] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Connexin 43 (Cx43) is a major determinant of conduction in the ventricular working myocardium of mammals. We investigated the effect of decreased Cx43 expression on conduction velocity and arrhythmogenesis using adult mice with inducible deletion of Cx43. METHODS AND RESULTS Cx43Cre-ER(T)/+ mice, in which 1 coding region of the Cx43 gene was replaced by Cre-ER(T), were mated to Cx43fl/fl mice, generating Cx43Cre-ER(T)/fl mice. Application of 4-hydroxytamoxifen (4-OHT) induced Cre-ER(T)-mediated deletion of the floxed Cx43 allele. Epicardial ventricular mapping using a 13x19 multiterminal electrode grid (300-microm spacing) was performed on Langendorff-perfused hearts from Cx43fl/fl plus carrier (n=10), Cx43fl/fl plus 4-OHT (n=10), Cx43 Cre-ER(T)/fl plus carrier (n=9), and Cx43Cre-ER(T)/fl plus 4-OHT (n=10). Cx43 protein amount in group 3 hearts was decreased by 50% compared with group 1. 4-OHT did not affect cardiac protein amounts in group 2 but decreased Cx43 expression up to 95% in group 4 compared with group 3. Epicardial activation of both left ventricle (LV) and right ventricle (RV) during sinus rhythm was similar in all groups. Conduction velocity (CV) changed only in group 4 animals. For RV (LV), longitudinal CV decreased from 38 (35) to 31.6 (33.6) and transverse CV from 24.4 (16.8) to 10.1 (11.3) cm/s. Dispersion of conduction in RV (LV) was increased by 91% (38%). Programmed stimulation resulted in ventricular arrhythmias in group 4 (7 of 10 mice) but never in groups 1 through 3. CONCLUSIONS Heterozygous expression of Cx43 did not affect ventricular conduction velocity. Up to 95% decrease of Cx43 protein in 4-OHT-treated Cx43(Cre-ER(T)/fl) mice reduced conduction velocity and increased dispersion of conduction and propensity for ventricular arrhythmias.
Collapse
Affiliation(s)
- Harold V M van Rijen
- Department of Medical Physiology, University Medical Center Utrecht, PO Box 80043, 3508TA Utrecht, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|
258
|
Rabaçal C, Mendonça C, Nuno L, Almeida A, Afonso S. Brugada syndrome complicated with sudden death. Rev Port Cardiol 2004; 23:217-23. [PMID: 15116457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
Brugada syndrome is an electrocardiographic diagnosis that is increasingly recognized as a cause of sudden cardiac death. The authors present a clinical case of a patient with a family history of sudden death, in whom a diagnosis of Brugada syndrome had been established, and who died suddenly. They also present a brief review of the main findings of this entity, particularly the diagnostic criteria and treatment of choice, since it is recognized that its prevalence will rise in the coming years.
Collapse
Affiliation(s)
- Carlos Rabaçal
- Serviço de Cardiologia Hospital de Reynaldo dos Santos, Vila Franca de Xira, Portugal
| | | | | | | | | |
Collapse
|
259
|
Abstract
We evaluated a family with 30 members, 3 of whom had incessant polymorphous and bidirectional ventricular tachycardia (VT) that was electrocardiographically similar to that described in other familial polymorphic VT series; the VT was unrelated to exercise and asymptomatic. More subtle, but morphologically similar, ventricular arrhythmias were detected in 3 other family members. Genes related to intracellular calcium transport were specifically excluded.
Collapse
Affiliation(s)
- Eyal Nof
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | | | | | | | | | | | | |
Collapse
|
260
|
Laitinen PJ, Swan H, Piippo K, Viitasalo M, Toivonen L, Kontula K. Genes, exercise and sudden death: molecular basis of familial catecholaminergic polymorphic ventricular tachycardia. Ann Med 2004; 36 Suppl 1:81-6. [PMID: 15176428 DOI: 10.1080/17431380410032599] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Familial catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disease manifesting with exercise- or stress-induced ventricular arrhythmias, syncope, and even sudden death. CPVT is inherited as an autosomal dominant or autosomal recessive trait, usually with high penetrance. We characterized in detail the clinical, structural and electrocardiographic findings in this disorder and by use of genome-wide linkage analysis, mapped the disease-causing gene to chromosome 1q42-q43. Thereafter, we and others demonstrated point mutations of the cardiac ryanodine receptor gene (RyR2) to underlie this life-threatening disease. In addition, RyR2 mutations were identified in patients affected with a variant form of arrhythmogenic right ventricular dysplasia (ARVD2), a phenotypically distinct disease entity. Identification of the causal mutations has enabled molecular diagnosis in the affected families, which is of major importance in identifying individuals at risk of an arrhythmia. Recently, several groups have delineated the functional effects of the RyR2 mutations associated with CPVT and ARVD2. The results are slightly contradictory, and further studies are thus needed to clarify the exact molecular mechanisms leading to arrhythmia induction.
Collapse
Affiliation(s)
- Päivi J Laitinen
- Research Program in Molecular Medicine, Biomedicum Helsinki, Finland
| | | | | | | | | | | |
Collapse
|
261
|
Abstract
Until recently, sudden cardiac death in a young person often remained an unexplained tragedy. However, in the last decade there have been dramatic advances in medical knowledge regarding inheritable dysrhythmias that increase the risk of SCD in otherwise healthy young individuals. The primary mechanism in this group of dysrhythmias appears to be an alteration of cardiac repolarization. In some diseases, the specific genes affected and even precise cellular mechanisms have been identified. The information about these diseases is often complex and rapidly evolving, challenging both healthcare providers and the families who must make important decisions based on emerging and incomplete information. The purpose of this article is to describe current understanding of the repolarization-related dysrhythmias and discuss the clinical implications for advanced practice nurses.
Collapse
Affiliation(s)
- Sarah S Leroy
- University of Michigan Congenital Heart Center, Ann Arbor, MI 48109-0204, USA.
| | | |
Collapse
|
262
|
González-Hermosillo JA. [Electrocardiogram in channel disorders]. Arch Cardiol Mex 2004; 74 Suppl 1:S79-83. [PMID: 15216752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
The ion channel diseases of the heart are a collection of genetically distinct arrhythmogenic cardiovascular disorders resulting from mutations in fundamental cardiac ion channels that orchestrate the action potential of the human heart. Our understanding of these genetic "channelopathies" has increased dramatically from electrocardiographic depictions of QT prolongations, ST-T alterations and torsades de pointes and clinical descriptions of people experiencing syncope and sudden death to molecular revelations of perfurbed ion channel genes. These exciting molecular breakthroughs have provided new opportunities for translational research with investigations into genotype-phenotype correlations and gene targeted therapies.
Collapse
Affiliation(s)
- Jesús Antonio González-Hermosillo
- Departamento de Electrofisiología Cardíaca, Instituto Nacional de Cardiología, Ignacio Chávez INCICH, Juan Badiano No. 1 Col. Sección XVI, Tlalpan 14080 México, D.F
| |
Collapse
|
263
|
Lahat H, Pras E, Eldar M. A missense mutation in CASQ2 is associated with autosomal recessive catecholamine-induced polymorphic ventricular tachycardia in Bedouin families from Israel. Ann Med 2004; 36 Suppl 1:87-91. [PMID: 15176429 DOI: 10.1080/17431380410032517] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Catecholamine-induced polymorphic ventricular tachycardia (CPVT) is characterized by episodes of syncope, seizures or sudden death, in response to physical activity or emotional stress, and affects mainly young children with morphologically normal hearts. We have recently described an autosomal recessive form of the disorder in seven families from a Bedouin tribe in the north of Israel, and mapped the disease-causing gene to chromosome 1p13-1p21. Direct sequencing of the calsequestrin 2 (CASQ2), a candidate gene from within the linkage interval, revealed a negatively charged aspartic acid change to a positively charged histidine at position 307 of the protein. CASQ2 serves as the major calcium reservoir within cardiac myocytes. This mutation occurs in a highly conserved residue of the protein. The implication of the calcium release cascade in this disease, may lead to a better understanding of the pathophysiologic events underlying ventricular tachycardia, and to the use of drugs directly involved in intracellular calcium control for the treatment of the CPVT patients.
Collapse
Affiliation(s)
- Hadas Lahat
- Heart Institute, Sheba Medical Center, Tel Hashomer, Israel.
| | | | | |
Collapse
|
264
|
Abstract
Based on similarity of electrocardiographic features, bidirectional ventricular tachycardia has been considered a variant of long QT syndrome. Genes causing long QT syndrome were used as candidate genes in 4 patients with bidirectional ventricular tachycardia. In 2 patients, we identified a common low penetrance HERG allele (R1047L) with an intermediate biophysical phenotype.
Collapse
|
265
|
Yi SD, Meng SR, Cui YK, Chen ZM, Peng J. [PCR-based site-directed mutagenesis and recombinant expression plasmid construction of a SCN5A mutation (K317N) identified in a Chinese family with Brugada syndrome]. Di Yi Jun Yi Da Xue Xue Bao 2003; 23:1139-42. [PMID: 14625171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
OBJECTIVE To perform PCR-based site-directed mutagenesis of a new SCN5A mutation (K317N) identified in a Chinese family with Brugada syndrome and construct the recombinant expression plasmid pRc/CMV-Hh1 containing the human cardiac sodium channel alpha subunit (hH1), mutant cDNA. METHODS A pair of primers was designed according to the restricted sites Sse 8387I and Age I of the SCN5A sequence with the mismatches introduced into primers. Mutagenesis was performed in a single-step PCR, and the fragments amplified by PCR containing the mutation site were subcloned into the pRc/CMV-hH1 vector. RESULTS Sequence analysis confirmed the presence of the desired mutation site, and a mutation from K (Lys) to N (Asn) in codon 317 was identified in the SCN5A gene, indicating the successful induction of the mutation at K317N of the SCN5A gene. CONCLUSION PCR site-directed mutagenesis is accurate and highly efficient, and the successfully constructed recombinant expression plasmid pRc/CMV-hH1 (K317N) may provide a molecular basis for further functional and genomic investigation of SCN5A.
Collapse
Affiliation(s)
- Shao-dong Yi
- Department of Cardiology, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
| | | | | | | | | |
Collapse
|
266
|
Abstract
Ca2+ release from the sarcoplasmic reticulum mediated by the cardiac ryanodine receptor (RyR2) is a fundamental event in cardiac muscle contraction. RyR2 mutations suggested to cause defective Ca2+ channel function have recently been identified in catecholaminergic polymorphic ventricular tachycardia (CPVT) and arrhythmogenic right ventricular dysplasia (ARVD) affected individuals. We report expression of three CPVT-linked human RyR2 (hRyR2) mutations (S2246L, N4104K, and R4497C) in HL-1 cardiomyocytes displaying correct targeting to the endoplasmic reticulum. N4104K also localized to the Golgi apparatus. Phenotypic characteristics including intracellular Ca2+ handling, proliferation, viability, RyR2:FKBP12.6 interaction, and beat rate in resting HL-1 cells expressing mutant hRyR2 were indistinguishable from wild-type (WT) hRyR2. However, Ca2+ release was augmented in cells expressing mutant hRyR2 after RyR activation (caffeine and 4-chloro-m-cresol) or beta-adrenergic stimulation (isoproterenol). RyR2:FKBP12.6 interaction remained intact after caffeine or 4-CMC activation, but was dramatically disrupted by isoproterenol or forskolin, an activator of adenylate cyclase. Isoproterenol and forskolin elevated cyclic-AMP to similar magnitudes in all cells and were associated with equivalent hyperphosphorylation of mutant and WT hRyR2. CPVT-linked mutations in hRyR2 did not alter resting cardiomyocyte phenotype but mediated augmented Ca2+ release on RyR-agonist or beta-AR stimulation. Furthermore, equivalent interaction between mutant and WT hRyR2 and FKBP12.6 was demonstrated.
Collapse
Affiliation(s)
- Christopher H George
- Wales Heart Research Institute, University of Wales College of Medicine, Heath Park, Cardiff, UK.
| | | | | |
Collapse
|
267
|
|
268
|
Eldar M, Pras E, Lahat H. A missense mutation in a highly conserved region of CASQ2 is associated with autosomal recessive catecholamine-induced polymorphic ventricular tachycardia in Bedouin families from Israel. Cold Spring Harb Symp Quant Biol 2003; 67:333-7. [PMID: 12858557 DOI: 10.1101/sqb.2002.67.333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
MESH Headings
- Adrenergic beta-Antagonists/therapeutic use
- Base Sequence
- Calsequestrin/chemistry
- Calsequestrin/genetics
- Calsequestrin/physiology
- Catecholamines/physiology
- Child
- Child, Preschool
- Chromosomes, Human, Pair 1/genetics
- Conserved Sequence
- DNA/genetics
- Electrocardiography
- Ethnicity/genetics
- Female
- Genes, Recessive
- Genetic Linkage
- Humans
- Israel
- Male
- Models, Molecular
- Mutation, Missense
- Polymorphism, Genetic
- Propranolol/therapeutic use
- Protein Conformation
- Tachycardia, Ventricular/drug therapy
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/physiopathology
Collapse
Affiliation(s)
- M Eldar
- Heart Institute, Sheba Medical Center, 52621 Tel Hashomer, Israel
| | | | | |
Collapse
|
269
|
Tanaka M, Berul CI, Ishii M, Jay PY, Wakimoto H, Douglas P, Yamasaki N, Kawamoto T, Gehrmann J, Maguire CT, Schinke M, Seidman CE, Seidman JG, Kurachi Y, Izumo S. A mouse model of congenital heart disease: cardiac arrhythmias and atrial septal defect caused by haploinsufficiency of the cardiac transcription factor Csx/Nkx2.5. Cold Spring Harb Symp Quant Biol 2003; 67:317-25. [PMID: 12858555 DOI: 10.1101/sqb.2002.67.317] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- M Tanaka
- Cardiovascular Division, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
270
|
Abstract
Macrovoltage T wave alternans (TWA) has been described in congenital long QT syndrome (LQTS). Microvoltage T wave alternans (microV-TWA) at low heart rate (HR) is a marker of arrhythmogenic risk in many conditions, but its significance in LQTS has not been established. Twenty-three genotypically heterogeneous patients with LQTS and 16 control subjects were studied at rest and during phenylephrine and dobutamine provocation. Genotyping was established by PCR amplification and DNA sequencing of the three most common LQTS genes; KCNQ1/KVLQT1 (LQT1), KCNH2/HERG (LQT2), and SCN5A (LQT3). microV-TWA was determined using Fast Fourier transform. Precluded by ectopy, microV-TWA could not be assessed in 8 of 23 patients with LQTS. In the remaining 15 patients with LQTS, microV-TWA occurred at lower HR in LQTS than in controls (117 +/- 49 vs 153 +/- 37 beats/min; P < 0.05). Patients with LQTS developed microV-TWA at HR < 150 beats/min more often than controls (10/15 vs 2/16; P = 0.003). However, microV-TWA was not detected in the 3 individuals with a history of out-of-hospital cardiac arrest including a 14-year-old male with an F339del-KVLQT1 mutation (LQT1) who had dobutamine-provoked polymorphic ventricular tachycardia requiring external defibrillation. Catecholamine-provoked microV-TWA occurs at lower HR in patients with LQTS than in healthy people but does not identify high risk subjects.
Collapse
Affiliation(s)
- Jan Nemec
- Department of Internal Medicine/Division of Cardiovascular Diseases, Mayo Clinic, Rochester Minnesota 55905, USA
| | | | | | | | | |
Collapse
|
271
|
Dulac Y, Acar P, Delay M. [Diagnosis of adrenergic ventricular tachycardia in two homozygotic twins]. Arch Mal Coeur Vaiss 2003; 96:521-3. [PMID: 12838845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
The authors report the first case of adrenergic ventricular tachycardia observed in two 11 year old homozygotic twins. Syncope on exercise led to the investigation of the first twin with confirmation of the diagnosis by exercise stress testing. The same investigations led to the demonstration of the condition in the second asymptomatic twin. The two patients were treated with nadolol and there has been no recurrence of syncope with a 2 year follow-up. Adrenergic ventricular tachycardia is a rare arrhythmia with a risk of sudden death which may be prevented by betablocker therapy. An exhaustive familial inquiry is essential, but is only positive in one out of three cases. Mutations in the ryanodine receptor gene (hRyRZ) and also in the calsequestrin gene (CASQ2) have recently been reported. Progress in the understanding of the genetics of this condition should improve primary preventive measures.
Collapse
Affiliation(s)
- Y Dulac
- Unité de cardiologie pédiatrique, hôpital des Enfants, 330, av. de Grande-Bretagne, BP 3119, 31026 Toulouse
| | | | | |
Collapse
|
272
|
Eldar M, Pras E, Lahat H. A missense mutation in the CASQ2 gene is associated with autosomal-recessive catecholamine-induced polymorphic ventricular tachycardia. Trends Cardiovasc Med 2003; 13:148-51. [PMID: 12732448 DOI: 10.1016/s1050-1738(03)00025-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Catecholamine-induced polymorphic ventricular tachycardia (CPVT), a rare disease that occurs in subjects without obvious organic heart disease, is characterized by episodes of syncope, seizures, or sudden death in response to physiologic or emotional stress. This report reviews evidence that a missense mutation in the CASQ2 gene is associated with autosomal-recessive CPVT.
Collapse
Affiliation(s)
- Michael Eldar
- Heart Institute, Sheba Medical Center, Tel Hashomer, Israel.
| | | | | |
Collapse
|
273
|
Paul M, Schulze-Bahr E, Breithardt G, Wichter T. Genetics of arrhythmogenic right ventricular cardiomyopathy--status quo and future perspectives. Z Kardiol 2003; 92:128-36. [PMID: 12596074 DOI: 10.1007/s00392-003-0892-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary myocardial disorder of unknown origin. In recent years, the disease has been recognized as a major cause of ventricular tachyarrhythmias and sudden cardiac death in young patients with apparently normal hearts. Although characteristic structural, imaging and electrocardiographic features are included in a proposed catalogue of diagnostic criteria, the correct diagnosis of ARVC often remains difficult. Much effort has been undertaken to enlarge the knowledge on pathophysiological mechanisms of the disease. The role of molecular genetics for the pathogenesis of ARVC is discussed in the following review. On the basis of linkage analyses in large families affected by ARVC, there is growing evidence for genetic alterations in ARVC, which, in the majority of chromosomal loci (seven) reported so far, follow a Mendelian autosomal-dominant pattern of inheritance with variable penetrance and polymorphic phenotype. Besides this, two autosomal-recessive forms of ARVC are known. These can be differentiated from the autosomal-dominant forms not only in terms of the mode of inheritance but also as to their specific phenotype: patients with Naxos disease exhibit characteristic hair and skin abnormalities and experience a more severe course of disease. Patients with another autosomal-recessive form display the typical but milder signs of ARVC together with opacifications of the crystalline lens. So far, two mutations in cardiac genes responsible for the development of ARVC have been reported. A homozygous two base pair deletion in the gene encoding for the cytoskeletal protein plakoglobin seems to account for the evolution of Naxos disease. The second mutation affecting the cardiac ryanodine receptor gene was found in patients with ARVC-2. Routine genetic testing of patients or relatives with a suspected diagnosis of ARVC is not available at present but may become the future gold standard with potential implications for a better understanding of the pathogenesis and management of the disease.
Collapse
Affiliation(s)
- M Paul
- Universitätsklinikum Münster, Medizinische Klinik und Poliklinik C-Kardiologie und Angiologie, Albert-Schweitzer-Strasse 33, 48149 Münster, Germany.
| | | | | | | |
Collapse
|
274
|
|
275
|
Tiso N, Salamon M, Bagattin A, Danieli GA, Argenton F, Bortolussi M. The binding of the RyR2 calcium channel to its gating protein FKBP12.6 is oppositely affected by ARVD2 and VTSIP mutations. Biochem Biophys Res Commun 2002; 299:594-8. [PMID: 12459180 DOI: 10.1016/s0006-291x(02)02689-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Arrhythmogenic right ventricular dysplasia/cardiomyopathy type 2 (ARVD2, OMIM 600996) and stress-induced polymorphic ventricular tachycardia (VTSIP, OMIM 604772) are two cardiac diseases causing juvenile sudden death, both associated with mutations in the RyR2 calcium channel. By using a quantitative yeast two-hybrid system, we show that VTSIP- and ARVD2-associated point mutations influence positively and negatively, respectively, the binding of RyR2 to its gating protein FKBP12.6. These findings suggest that ARVD2 mutations increase RyR2-mediated calcium release to cytoplasm, while VTSIP mutations do not affect significantly cytosolic calcium levels, thereby explaining the clinical differences between the two diseases. The present two-hybrid system appears to be an efficient molecular tool to assay the binding of FKBP12s proteins to both cardiac RyR2 and skeletal muscle RyR1 isoforms, circumventing the full-length expression of this class of giant channels. We also provide evidence of the suitability of this system to test new drugs that target RyRs-FKBP12s interactions and do not affect yeast growth.
Collapse
Affiliation(s)
- Natascia Tiso
- Department of Biology, University of Padova, via U. Bassi 58/B, I-35131 Padua, Italy.
| | | | | | | | | | | |
Collapse
|
276
|
Wichter T, Schulze-Bahr E, Eckardt L, Paul M, Levkau B, Meyborg M, Schäfers M, Haverkamp W, Breithardt G. Molecular mechanisms of inherited ventricular arrhythmias. Herz 2002; 27:712-39. [PMID: 12574890 DOI: 10.1007/s00059-002-2436-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Inherited ventricular arrhythmias such as the long QT syndrome (LQTS), Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), idiopathic ventricular fibrillation (VF), and arrhythmogenic right ventricular cardiomyopathy (ARVC) account for a relevant proportion of sudden cardiac death cases in young patients cohorts. The detailed pathogenetic mechanisms of inherited ventricular arrhythmias are still poorly understood because systematic investigations are difficult to perform due to low patient numbers and the lack of appropriate experimental models. However, recent advances in research and science have identified a genetic background for many of these diseases. PRESENT KNOWLEDGE In LQTS, various mutations in different genes encoding for cardiac potassium and sodium channel proteins have been identified ("channelopathy"), and initial progress in genotype-phenotype correlation is made. Mutations in the cardiac sodium channel gene have also been identified in a subset of patients with Brugada syndrome, whereas a genetic background has not yet been demonstrated in idiopathic VF and right ventricular outflow-tract tachycardia (RVO-VT). Very recently, mutations in the cardiac ryanodine receptor gene have been identified in CPVT and in a subgroup of patients with ARVC. Although several chromosomal loci were suggested, no other responsible genes or mutations have been found in autosomal dominant forms of ARVC. However, in Naxos disease, a recessive form of ARVC with coexpression of palmoplantar keratoderma and woolly hair, a mutation in the plakoglobin gene has recently been discovered, thus underscoring the potential role of genetic alterations in cytoskeletal proteins in ARVC. FUTURE PERSPECTIVES In the next years, significant progress in the genetic diagnosis pathophysiologic understanding of disease mechanisms, genotype-phenotype correlation, and the development of gene- or target-directed treatment strategies can be expected in the field of inherited ventricular arrhythmias. CONCLUSION This review summarizes the current knowledge of the molecular mechanisms, including aspects of pathoanatomy, autonomic innervation, genetics, and genotype-phenotype correlations with their potential implications for diagnosis and treatment of inherited ventricular arrhythmias.
Collapse
Affiliation(s)
- Thomas Wichter
- Department of Cardiology and Angiology, Institute for Arteriosclerosis Research, University of Münster, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
277
|
Abstract
INTRODUCTION Recent advances in molecular genetic research have provided new insights into severe ventricular arrhythmias related to channelopathies. CASE REPORT A case of Andersen's syndrome followed during fourteen years is reported. This rare familial periodic paralysis is characterized by its association with dysmorphic features (micrognatia) and ventricular arrhythmias. COMMENTS Andersen's syndrome has been attributed to a mutation in the KCNJ2 gene which is involved not only in stabilizing cardiac rhythm, but also in modulating the excitability of skeletal muscle and in morphogenesis. This disease must be distinguished from hyperkalemic periodic paralysis due to a mutation in the skeletal muscle sodium channel gene (SCN4A) and from hypokalemic periodic paralysis related to dihydropyridine receptor mutation (CACNL1A3). Furthermore, it may not be confused with others rhythmic channelopathies (long QT syndromes, catecholaminergic polymorphic ventricular tachycardia and Brugada's syndrome).
Collapse
MESH Headings
- Adolescent
- Adult
- Child
- Chromosomes, Human, Pair 17/genetics
- Diagnosis, Differential
- Glycogen Storage Disease Type IV/diagnosis
- Glycogen Storage Disease Type IV/drug therapy
- Glycogen Storage Disease Type IV/genetics
- Humans
- Male
- Micrognathism/genetics
- Mutation
- Paralyses, Familial Periodic/diagnosis
- Paralyses, Familial Periodic/drug therapy
- Paralyses, Familial Periodic/genetics
- Potassium Channels, Inwardly Rectifying/genetics
- Tachycardia, Ventricular/diagnosis
- Tachycardia, Ventricular/drug therapy
- Tachycardia, Ventricular/genetics
Collapse
Affiliation(s)
- V Lucet
- Unité de rythmologie pédiatrique, Château des Côtes, 78350 Les Loges-en-Josas, France.
| | | | | |
Collapse
|
278
|
Lahat H, Eldar M. Autosomal recessive catecholamine-induced polymorphic ventricular tachycardia. Isr Med Assoc J 2002; 4:1095-6. [PMID: 12516898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Hadas Lahat
- Danek Gartner Institute of Human Genetics, Neufeld Cardiac Research Institute and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel
| | | |
Collapse
|
279
|
Kotzot D, Hoffmann K, Kujat A, Holland H, Froster UG, Mücke J. Implications of FISH investigations in MIDAS syndrome associated with a 46,XX,t(X;Y) karyotype. Am J Med Genet 2002; 113:108-10. [PMID: 12400076 DOI: 10.1002/ajmg.10718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
MESH Headings
- Chromosomes, Human, Y
- DNA-Binding Proteins/genetics
- Female
- Gonadal Dysgenesis, 46,XX/genetics
- Gonadal Dysgenesis, 46,XY/genetics
- Humans
- In Situ Hybridization, Fluorescence
- Karyotyping
- Male
- Nuclear Proteins
- Sex-Determining Region Y Protein
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/pathology
- Transcription Factors
- Translocation, Genetic
Collapse
|
280
|
Postma AV, Denjoy I, Hoorntje TM, Lupoglazoff JM, Da Costa A, Sebillon P, Mannens MMAM, Wilde AAM, Guicheney P. Absence of calsequestrin 2 causes severe forms of catecholaminergic polymorphic ventricular tachycardia. Circ Res 2002; 91:e21-6. [PMID: 12386154 DOI: 10.1161/01.res.0000038886.18992.6b] [Citation(s) in RCA: 281] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disorder characterized by syncopal events and sudden cardiac death at a young age during physical stress or emotion, in the absence of structural heart disease. We report the first nonsense mutations in the cardiac calsequestrin gene, CASQ2, in three CPVT families. The three mutations, a nonsense R33X, a splicing 532+1 G>A, and a 1-bp deletion, 62delA, are thought to induce premature stop codons. Two patients who experienced syncopes before the age of 7 years were homozygous carriers, suggesting a complete absence of calsequestrin 2. One patient was heterozygous for the stop codon and experienced syncopes from the age of 11 years. Despite the different mutations, there is little phenotypic variation of CPVT for the CASQ2 mutations. Of the 16 heterozygous carriers of these various mutations, 14 were devoid of clinical symptoms or ECG anomalies, whereas 2 of them had ventricular arrhythmias at ECG on exercise tests. In line with this, the diagnosis of the probands was difficult because of the absence of a positive family history. In conclusion, these additional three CASQ2 CPVT families suggest that CASQ2 mutations are more common than previously thought and produce a severe form of CPVT. The full text of this article is available at http://www.circresaha.org.
Collapse
Affiliation(s)
- Alex V Postma
- INSERM U523, Institut de Myologie, IFR Coeur, muscles et vaisseaux No. 14, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
281
|
Kitamura H, Ohnishi Y, Yoshida A, Okajima K, Azumi H, Ishida A, Galeano EJ, Kubo S, Hayashi Y, Itoh H, Yokoyama M. Heterogeneous loss of connexin43 protein in nonischemic dilated cardiomyopathy with ventricular tachycardia. J Cardiovasc Electrophysiol 2002; 13:865-70. [PMID: 12380923 DOI: 10.1046/j.1540-8167.2002.00865.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Gap junction alterations recently have been implicated in chronic heart failure, but direct evidence between gap junction manifestation in nonischemic dilated cardiomyopathy (DCM) is lacking. The current study examines whether qualitative changes or altered distribution of gap junctional connexin43 (Cx43) are related to global ventricular function and ventricular arrhythmia in DCM. METHODS AND RESULTS We investigated 31 DCM patients (52 +/- 15 years) and 5 control subjects (55 +/- 10 years). Expression of Cx43 proteins was qualitatively and quantitatively determined using immunoconfocal microscopy in right ventricular biopsy specimens from each patient. The expression level of Cx43 protein was defined as the proportion of tissue area occupied by Cx43 (percent tissue area) in each test area. Cx43 immunoreactive signal expressed as percent tissue area was not correlated with the change in left ventricular ejection fraction (P = 0.17). Of 31 DCM patients, 23% subsequently developed sustained ventricular tachycardia (VT), which allowed retrospective division of the samples into two groups: non-VT and VT. Left ventricular ejection fraction was comparable in both groups, but the percent tissue area in the VT groups was significantly decreased compared with that of the non-VT groups (P = 0.03). Furthermore, Cx43 protein was distributed heterogeneously in the VT groups (P < 0.0001). CONCLUSION Heterogeneous reduction of Cx43 protein may result in development of malignant ventricular arrhythmia in DCM.
Collapse
Affiliation(s)
- Hidetsuna Kitamura
- Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
282
|
Moreno AP. Filling more gaps: consequences of heterogeneous remodeling in connexin expression. J Cardiovasc Electrophysiol 2002; 13:871-2. [PMID: 12380924 DOI: 10.1046/j.1540-8167.2002.00871.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
283
|
Jiang D, Xiao B, Zhang L, Chen SRW. Enhanced basal activity of a cardiac Ca2+ release channel (ryanodine receptor) mutant associated with ventricular tachycardia and sudden death. Circ Res 2002; 91:218-25. [PMID: 12169647 DOI: 10.1161/01.res.0000028455.36940.5e] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations in the human cardiac Ca2+ release channel (ryanodine receptor, RyR2) gene have recently been shown to cause effort-induced ventricular arrhythmias. However, the consequences of these disease-causing mutations in RyR2 channel function are unknown. In the present study, we characterized the properties of mutation R4496C of mouse RyR2, which is equivalent to a disease-causing human RyR2 mutation R4497C, by heterologous expression of the mutant in HEK293 cells. [3H]ryanodine binding studies revealed that the R4496C mutation resulted in an increase in RyR2 channel activity in particular at low Ca2+ concentrations. This increased basal channel activity remained sensitive to modulation by caffeine, ATP, Mg2+, and ruthenium red. In addition, the R4496C mutation enhanced the sensitivity of RyR2 to activation by Ca2+ and by caffeine. Single-channel analysis showed that single R4496C mutant channels exhibited considerable channel openings at low Ca2+ concentrations. HEK293 cells transfected with mutant R4496C displayed spontaneous Ca2+ oscillations more frequently than cells transfected with wild-type RyR2. Substitution of a negatively charged glutamate for the positively charged R4496 (R4496E) further enhanced the basal channel activity, whereas replacement of R4496 by a positively charged lysine (R4496K) had no significant effect on the basal activity. These observations indicate that the charge and polarity at residue 4496 plays an essential role in RyR2 channel gating. Enhanced basal activity of RyR2 may underlie an arrhythmogenic mechanism for effort-induced ventricular tachycardia.
Collapse
Affiliation(s)
- Dawei Jiang
- Cardiovascular Research Group, Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada
| | | | | | | |
Collapse
|
284
|
|
285
|
Bauce B, Rampazzo A, Basso C, Bagattin A, Daliento L, Tiso N, Turrini P, Thiene G, Danieli GA, Nava A. Screening for ryanodine receptor type 2 mutations in families with effort-induced polymorphic ventricular arrhythmias and sudden death: early diagnosis of asymptomatic carriers. J Am Coll Cardiol 2002; 40:341-9. [PMID: 12106942 DOI: 10.1016/s0735-1097(02)01946-0] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES We sought to establish the role of genetic screening for ryanodine receptor type 2 (RyR2) gene mutations in families with effort-induced polymorphic ventricular arrhythmia (PVA), syncope and juvenile sudden death. BACKGROUND The RyR2 mutations have been associated with PVA, syncope and sudden death in response to physical or emotional stress. METHODS We studied 81 subjects (39 males and 42 females; mean age 31 +/- 20 years) belonging to eight families with pathogenic RyR2 mutations. All subjects underwent screening for RyR2 mutations, electrocardiography (ECG), 24-h Holter monitoring, signal-averaged electrocardiography (SAECG), two-dimensional echocardiography and exercise stress testing. Electrophysiologic (EP) study was performed in nine patients. RESULTS Six different RyR2 mutations were found in eight families. Forty-three family members carried the gene mutation. Of these, 28 (65%) showed effort-induced arrhythmic symptoms or signs and one died suddenly during follow-up. Family history revealed 19 juvenile cases of sudden death during effort or emotion. In two families sharing the same mutation, no subject presented with PVA during the stress test; thus, sudden death and syncope were the only clinical manifestations. The 12-lead ECG was normal in all but two subjects, whereas five patients showed positive late potentials on the SAECG. In 17 (39.5%) of 43 subjects, the two-dimensional echocardiogram revealed localized kinetic abnormalities and mild structural alterations of the right ventricle. The EP study was not able to induce PVA. CONCLUSIONS The absence of symptoms and PVA on the stress test in more than one-third of carriers of RyR2 mutations, as well as the lack of PVA inducibility by the EP study, underlies the importance of genetic screening for the early diagnosis of asymptomatic carriers and prevention of sudden death.
Collapse
Affiliation(s)
- Barbara Bauce
- Department of Cardiology, University of Padua Medical School, Via A. Gabelli, 86-35121 Padua, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
286
|
Priori SG, Napolitano C, Memmi M, Colombi B, Drago F, Gasparini M, DeSimone L, Coltorti F, Bloise R, Keegan R, Cruz Filho FES, Vignati G, Benatar A, DeLogu A. Clinical and molecular characterization of patients with catecholaminergic polymorphic ventricular tachycardia. Circulation 2002; 106:69-74. [PMID: 12093772 DOI: 10.1161/01.cir.0000020013.73106.d8] [Citation(s) in RCA: 768] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Mutations in the cardiac ryanodine receptor gene (RyR2) underlie catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited arrhythmogenic disease occurring in the structurally intact heart. The proportion of patients with CPVT carrying RyR2 mutations is unknown, and the clinical features of RyR2-CPVT as compared with nongenotyped CPVT are undefined. METHODS AND RESULTS Patients with documented polymorphic ventricular arrhythmias occurring during physical or emotional stress with a normal heart entered the study. The clinical phenotype of the 30 probands and of 118 family members was evaluated, and mutation screening on the RyR2 gene was performed. Arrhythmias documented in probands were: 14 of 30 bidirectional ventricular tachycardia, 12 of 30 polymorphic ventricular tachycardia, and 4 of 30 catecholaminergic idiopathic ventricular fibrillation; RyR2 mutations were identified in 14 of 30 probands (36% bidirectional ventricular tachycardia, 58% polymorphic ventricular tachycardia, 50% catecholaminergic idiopathic ventricular fibrillation) and in 9 family members (4 silent gene carriers). Genotype-phenotype analysis showed that patients with RyR2 CPVT have events at a younger age than do patients with nongenotyped CPVT and that male sex is a risk factor for syncope in RyR2-CPVT (relative risk=4.2). CONCLUSIONS CPVT is a clinically and genetically heterogeneous disease manifesting beyond pediatric age with a spectrum of polymorphic arrhythmias. beta-Blockers reduce arrhythmias, but in 30% of patients an implantable defibrillator may be required. Genetic analysis identifies two groups of patients: Patients with nongenotyped CPVT are predominantly women and become symptomatic later in life; patients with RyR2 CPVT become symptomatic earlier, and men are at higher risk of cardiac events. These data provide a rationale for prompt evaluation and treatment of young men with RyR2 mutations.
Collapse
Affiliation(s)
- Silvia G Priori
- Molecular Cardiology, IRCCS Fondazione S. Maugeri, University of Pavia, Pavia, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
287
|
|
288
|
Lehmann MH. Sex, shocks, and survival: sudden cardiac death prevention with implantable cardioverter defibrillators in women versus men. J Cardiovasc Electrophysiol 2002; 13:569-70. [PMID: 12108498 DOI: 10.1046/j.1540-8167.2002.00569.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
MESH Headings
- Death, Sudden, Cardiac/prevention & control
- Defibrillators, Implantable
- Electrophysiologic Techniques, Cardiac
- Female
- Genetic Predisposition to Disease
- Humans
- Male
- Sex Factors
- Shock, Cardiogenic/genetics
- Shock, Cardiogenic/mortality
- Shock, Cardiogenic/therapy
- Stroke Volume/genetics
- Survival Analysis
- Tachycardia, Ventricular/genetics
- Tachycardia, Ventricular/mortality
- Tachycardia, Ventricular/therapy
- Treatment Outcome
Collapse
|
289
|
Abstract
Pathogenesis of familial inherited arrhythmias is being progressively clarified thanks to the insights provided by molecular biology and by functional studies. Transmembrane or intracellular ion channel mutations have been identified in genetically determined forms of polymorphic ventricular tachycardia and sudden death such as catecholaminergic ventricular tachycardia, long QT syndrome, and Brugada syndrome. The role of molecular abnormalities in the genesis of monomorphic idiopathic ventricular tachycardias is less well defined, mainly because of the lack of a Mendelian pattern of inheritance. Interestingly, the presence of somatic mutations has been suggested as the mechanism for monomorphic ventricular tachycardia originating from the right ventricular outflow tract. The future goals for the application of molecular genetics to the management of cardiac arrhythmias will be to apply molecular genetics for a better risk stratification of affected individuals and to aim for the identification of gene-specific treatment of idiopathic ventricular tachycardia.
Collapse
Affiliation(s)
- Carlo Napolitano
- Molecular Cardiology Laboratories, Instituto di Ricovero e Cura a Carattere Scientifico Fondazione S. Maugeri, Pavia, Italy
| | | |
Collapse
|
290
|
Papadatos GA, Wallerstein PMR, Head CEG, Ratcliff R, Brady PA, Benndorf K, Saumarez RC, Trezise AEO, Huang CLH, Vandenberg JI, Colledge WH, Grace AA. Slowed conduction and ventricular tachycardia after targeted disruption of the cardiac sodium channel gene Scn5a. Proc Natl Acad Sci U S A 2002; 99:6210-5. [PMID: 11972032 PMCID: PMC122928 DOI: 10.1073/pnas.082121299] [Citation(s) in RCA: 292] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2001] [Accepted: 03/01/2002] [Indexed: 11/18/2022] Open
Abstract
Voltage-gated sodium channels drive the initial depolarization phase of the cardiac action potential and therefore critically determine conduction of excitation through the heart. In patients, deletions or loss-of-function mutations of the cardiac sodium channel gene, SCN5A, have been associated with a wide range of arrhythmias including bradycardia (heart rate slowing), atrioventricular conduction delay, and ventricular fibrillation. The pathophysiological basis of these clinical conditions is unresolved. Here we show that disruption of the mouse cardiac sodium channel gene, Scn5a, causes intrauterine lethality in homozygotes with severe defects in ventricular morphogenesis whereas heterozygotes show normal survival. Whole-cell patch clamp analyses of isolated ventricular myocytes from adult Scn5a(+/-) mice demonstrate a approximately 50% reduction in sodium conductance. Scn5a(+/-) hearts have several defects including impaired atrioventricular conduction, delayed intramyocardial conduction, increased ventricular refractoriness, and ventricular tachycardia with characteristics of reentrant excitation. These findings reconcile reduced activity of the cardiac sodium channel leading to slowed conduction with several apparently diverse clinical phenotypes, providing a model for the detailed analysis of the pathophysiology of arrhythmias.
Collapse
Affiliation(s)
- G Alex Papadatos
- Section of Cardiovascular Biology, Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
291
|
Abstract
In the last 50 years we have been very successful at prolonging survival and improving the quality of life of patients with cardiac disease. The innovations in technology and pharmacology, better preventive and diagnostic tools have provided tremendous breakthroughs. However, despite our best efforts, the majority of cardiac diseases are structural in origin and will progress to their ultimate outcome. Curative therapies are not available due in part to our poor understanding of the basic mechanisms responsible for these diseases. The new developments in molecular genetics and biology are likely to change the way we approach a cardiac patient in the future. The diseases are presently being deciphered at the most basic level, and the information obtained opens new possibilities not only for better therapeutic and diagnostic measures but also for prevention of the disease.
Collapse
|
292
|
Imazio M, Ghisio A, Coda L, Tidu M, Belli R, Trinchero R, Brusca A. Brugada syndrome: a case report of an unusual association with vasospastic angina and coronary myocardial bridging. Pacing Clin Electrophysiol 2002; 25:513-5. [PMID: 11991381 DOI: 10.1046/j.1460-9592.2002.00513.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This report describes a case of an unusual association between vasospastic angina, coronary myocardial bridging, and Brugada syndrome. The patient complained of chest pain followed by rhythmic palpitation and syncope. Brugada syndrome ECG markers were documented with transient ST-segment elevation in lateral leads. A coronary angiogram showed a myocardial bridging in the left anterior descending artery and coronary vasospasm was reproduced after intracoronary ergonovine injection in the circumflex coronary artery. Ventricular fibrillation was induced by programmed electrical stimulation. The described association can be important because interaction between ischemia and Brugada syndrome electrophysiological substrate could modulate individual susceptibility to life-threatening ventricular tachyarrhythmias.
Collapse
Affiliation(s)
- Massimo Imazio
- Cardiology Department, Maria Vittoria Hospital, Turin, Italy.
| | | | | | | | | | | | | |
Collapse
|
293
|
Affiliation(s)
- Kalyanam Shivkumar
- Cardiac Electrophysiology Section, Division of Cardiology, Department of Medicine, University of Iowa Hospitals and Clinics, Iowa City, USA.
| | | | | |
Collapse
|
294
|
Swan H, Viitasalo M, Toivonen L, Piippo K, Kontula K. [Hereditary polymorphic ventricular tachycardia as a cause of syncopes and sudden cardiac deaths]. Duodecim 2002; 116:589-94. [PMID: 11787111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Affiliation(s)
- H Swan
- HYKS:n sisätautien klinikka, kardiologian toimiala 00029 HYKS.
| | | | | | | | | |
Collapse
|
295
|
Affiliation(s)
- Heikki Swan
- Helsinki University Hospital, Helsinki, Finland.
| | | |
Collapse
|
296
|
Kuo HC, Cheng CF, Clark RB, Lin JJ, Lin JL, Hoshijima M, Nguyêñ-Trân VT, Gu Y, Ikeda Y, Chu PH, Ross J, Giles WR, Chien KR. A defect in the Kv channel-interacting protein 2 (KChIP2) gene leads to a complete loss of I(to) and confers susceptibility to ventricular tachycardia. Cell 2001; 107:801-13. [PMID: 11747815 DOI: 10.1016/s0092-8674(01)00588-8] [Citation(s) in RCA: 319] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
KChIP2, a gene encoding three auxiliary subunits of Kv4.2 and Kv4.3, is preferentially expressed in the adult heart, and its expression is downregulated in cardiac hypertrophy. Mice deficient for KChIP2 exhibit normal cardiac structure and function but display a prolonged elevation in the ST segment on the electrocardiogram. The KChIP2(-/-) mice are highly susceptible to the induction of cardiac arrhythmias. Single-cell analysis revealed a substrate for arrhythmogenesis, including a complete absence of transient outward potassium current, I(to), and a marked increase in action potential duration. These studies demonstrate that a defect in KChIP2 is sufficient to confer a marked genetic susceptibility to arrhythmias, establishing a novel genetic pathway for ventricular tachycardia via a loss of the transmural gradient of I(to).
Collapse
Affiliation(s)
- H C Kuo
- Institute of Molecular Medicine, UCSD-Salk Program in Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
297
|
Lahat H, Pras E, Olender T, Avidan N, Ben-Asher E, Man O, Levy-Nissenbaum E, Khoury A, Lorber A, Goldman B, Lancet D, Eldar M. A missense mutation in a highly conserved region of CASQ2 is associated with autosomal recessive catecholamine-induced polymorphic ventricular tachycardia in Bedouin families from Israel. Am J Hum Genet 2001; 69:1378-84. [PMID: 11704930 PMCID: PMC1235548 DOI: 10.1086/324565] [Citation(s) in RCA: 439] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2001] [Accepted: 09/25/2001] [Indexed: 11/03/2022] Open
Abstract
Catecholamine-induced polymorphic ventricular tachycardia (PVT) is characterized by episodes of syncope, seizures, or sudden death, in response to physical activity or emotional stress. Two modes of inheritance have been described: autosomal dominant and autosomal recessive. Mutations in the ryanodine receptor 2 gene (RYR2), which encodes a cardiac sarcoplasmic reticulum (SR) Ca(2+)-release channel, were recently shown to cause the autosomal dominant form of the disease. In the present report, we describe a missense mutation in a highly conserved region of the calsequestrin 2 gene (CASQ2) as the potential cause of the autosomal recessive form. The CASQ2 protein serves as the major Ca(2+) reservoir within the SR of cardiac myocytes and is part of a protein complex that contains the ryanodine receptor. The mutation, which is in full segregation in seven Bedouin families affected by the disorder, converts a negatively charged aspartic acid into a positively charged histidine, in a highly negatively charged domain, and is likely to exert its deleterious effect by disrupting Ca(2+) binding.
Collapse
Affiliation(s)
- Hadas Lahat
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Elon Pras
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Tsviya Olender
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Nili Avidan
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Edna Ben-Asher
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Orna Man
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Etgar Levy-Nissenbaum
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Asad Khoury
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Avraham Lorber
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Boleslaw Goldman
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Doron Lancet
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| | - Michael Eldar
- Danek Gartner Institute of Human Genetics and Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; The Crown Human Genome Center, Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot, Israel; and Institute of Pediatric Cardiology, Rambam Medical Center, Haifa, Israel
| |
Collapse
|
298
|
Abstract
This article describes a family characterized by combined cardiomyopathy and nonspecific skeletal myopathy who present in the third to fifth decades with cardiac manifestations but earlier have evidence of subtle skeletal muscle dysfunction. They differ from previously defined syndromes and potentially represent a different genetic expression or mutation. Cardiomyopathy presents with atrial arrhythmias including AF and atrial flutter. Life-threatening ventricular tachyarrhythmias occur next with onset of ventricular dysfunction. Electrophysiological study revealed sustained monomorphic VT. Affected family members benefitted from an ICD and progression to congestive heart failure (CHF) occurred late. Skeletal myopathy continues with marked progressive muscle weakness and inability to ambulate without assistance. Genetic analysis is currently ongoing. Neurological evaluation in all three family members revealed nonspecific myopathy affecting the psoas and iliopsoas muscles. Atrophy and wasting of the facial and temporalis muscles were common. Skeletal muscle biopsy revealed myofiber atrophy consistent with myopathy.
Collapse
Affiliation(s)
- S C Vlay
- Stony Brook Arrhythmia Study and Sudden Death Prevention Center, Division of Cardiology, Department of Medicine, Department of Neurology, SUNY Health Sciences Center, Stony Brook, New York, USA.
| | | | | |
Collapse
|
299
|
Takezako T, Zhang B, Serikawa T, Fan P, Nomoto J, Saku K. The D allele of the angiotensin-converting enzyme gene and reperfusion-induced ventricular arrhythmias in patients with acute myocardial infarction. Jpn Circ J 2001; 65:603-9. [PMID: 11446493 DOI: 10.1253/jcj.65.603] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The renin-angiotensin system may play a pivotal role in reperfusion ventricular arrhythmias (RVA). The purpose of this study was to investigate the association between angiotensin-converting enzyme (ACE) gene polymorphism and RVA in patients with acute myocardial infarction (AMI) in a case-control study. Patients who had undergone successful coronary intervention for AMI were enrolled (n= 127, male/female: 97/30, mean age, 62.6 years). The incidence of RVA was continuously monitored by ECG at a coronary care unit. The severity of ventricular arrhythmias was evaluated in terms of the Lown's grade and patients with a high risk of ventricular arrhythmias that may cause sudden cardiac death (Lown's grade > or =2) within 5 h of coronary intervention were defined as cases (n=59), and otherwise as controls (n=68). A receiver operating characteristic curve was used to determine the discriminatory ability of continuous variables and to produce dummy variables for use in a logistic regression analysis. Cases had a significantly higher body mass index, higher maximal levels of serum creatine kinase, and a shorter time preceding coronary intervention than controls. The severity of coronary atherosclerosis was similar between the 2 groups. The frequency distribution of ACE genotypes in cases differed from that in controls (II/ID/DD: 22.0%/52.6%/25.4% vs 44.1%/41.4%/14.7%, p<0.05, by the Mantel-Haenzel chi-square test). The ACE-D allele had additive and dominant effects with regard to the occurrence of significant ventricular arrhythmias after adjusting for other risk factors. The ACE-D allele may play a pivotal role in sudden cardiac death in patients with AMI.
Collapse
Affiliation(s)
- T Takezako
- Department of Cardiology, Fukuoka University School of Medicine, Japan
| | | | | | | | | | | |
Collapse
|
300
|
|