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Lu YY, Chen YC, Lin YK, Chen SA, Chen YJ. Electrical and Structural Insights into Right Ventricular Outflow Tract Arrhythmogenesis. Int J Mol Sci 2023; 24:11795. [PMID: 37511554 PMCID: PMC10380666 DOI: 10.3390/ijms241411795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/08/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023] Open
Abstract
The right ventricular outflow tract (RVOT) is the major origin of ventricular arrhythmias, including premature ventricular contractions, idiopathic ventricular arrhythmias, Brugada syndrome, torsade de pointes, long QT syndrome, and arrhythmogenic right ventricular cardiomyopathy. The RVOT has distinct developmental origins and cellular characteristics and a complex myocardial architecture with high shear wall stress, which may lead to its high vulnerability to arrhythmogenesis. RVOT myocytes are vulnerable to intracellular sodium and calcium overload due to calcium handling protein modulation, enhanced CaMKII activity, ryanodine receptor phosphorylation, and a higher cAMP level activated by predisposing factors or pathological conditions. A reduction in Cx43 and Scn5a expression may lead to electrical uncoupling in RVOT. The purpose of this review is to update the current understanding of the cellular and molecular mechanisms of RVOT arrhythmogenesis.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City 22174, Taiwan
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24257, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Cardiovacular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Cardiovascular Center, Taichung Veterans General Hospital, Taichung 40705, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Cardiovacular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11696, Taiwan
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Bera D, Saggu D, Yalagudri S, Kadel JK, Sarkar R, Devidutta S, Christopher J, Pavri B, Narasimhan C. Outflow-tract ventricular tachycardia: Can 12 lead ECG during sinus rhythm identify underlying cardiac sarcoidosis? Indian Pacing Electrophysiol J 2020; 20:83-90. [PMID: 32119909 PMCID: PMC7244880 DOI: 10.1016/j.ipej.2020.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 02/15/2020] [Accepted: 02/23/2020] [Indexed: 01/27/2023] Open
Abstract
Background Patients with outflow tract ventricular tachycardia (OTVT) with normal echocardiogram are labeled as idiopathic VT (IVT). However, a subset of these patients is subsequently diagnosed with underlying cardiac sarcoidosis (CS). Objective:Whether electrocardiogram (ECG) abnormalities in sinus rhythm (SR) can differentiate underlying CS from IVT. Methods We retrospectively analyzed the SR-ECGs of 42 patients with OTVT/premature ventricular complexes (PVC) and normal echocardiography. All underwent advanced imaging with cardiac magnetic resonance (CMR)/18FDG PET-CT for screening of CS. Twenty-two patients had significant abnormalities in cardiac imaging and subsequently had biopsy-proven CS (Cases). Twenty patients had normal imaging and were categorized as IVT (Controls). SR-ECGs of all patients were analyzed by 2 independent, blinded observers. Results Baseline characteristics were comparable. Among the ECG features analyzed – fascicular (FB) or bundle branch block (BBB) was seen in 9/22 Cases vs. 1/20 controls (p = 0.01). Among patients without FB or BBB, fragmented QRS (fQRS) was present in 9/13 cases but in none of the controls (p < 0.001). Low voltage QRS was more often seen among cases as compared to controls (10/22 vs. 3/20 p = 0.03). A stepwise algorithm based on these 3 sets of ECG findings helped to diagnose CS among patients presenting with OTVT/PVC with sensitivity of 91%, specificity of 75%, a PPV of 80%, and a NPV of 88%. Conclusions In patients presenting with OTVT/PVC: FB/BBB, fQRS, and low QRS voltage on the baseline ECG were more often observed among patients with underlying CS as compared to true IVT. These findings may help to distinguish underlying CS among Cases presenting with OTVT/PVC.
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Affiliation(s)
- Debabrata Bera
- Dept of Electrophysiology, Care Hospitals, Hyderabad, India
| | - Daljeet Saggu
- Dept of Electrophysiology, Care Hospitals, Hyderabad, India
| | | | | | | | | | | | - Behzad Pavri
- Thomas Jefferson University Hospital, Philadelphia, USA
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Clinical spectrum and long-term course of sustained ventricular tachycardia in pediatric patients: 10 years of experience. Anatol J Cardiol 2020; 25:313-322. [PMID: 33960306 DOI: 10.14744/anatoljcardiol.2020.95759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Pediatric ventricular tachycardias (VTs) have heterogeneous etiology and different clinical features. This study aimed to evaluate the clinical spectrum and long-term course of pediatric sustained VTs. METHODS Patients diagnosed as having sustained VT between 2010 and 2020 were evaluated retrospectively. RESULTS A total of 129 patients with VT were evaluated; 74 patients were male, and the median age was 12.5 years (0.25-18 years). Patients were grouped as having idiopathic VT (IVT) [n=85 (65.9%)], cardiomyopathy-associated VT (CMP-VT) [n=24 (18.6%)], catecholaminergic polymorphic VT [n=17 (13.2%)], and myocarditis-associated VT [n=3, (2.3%)]. Palpitations (n=61) and syncope (n=24) were the most common symptoms. VT originated from the right ventricle in 53.6% of the patients. Half of the patients underwent electrophysiological study, 64 patients received radiofrequency ablation therapy, and 29 patients had implantable cardiac defibrillators. During the follow-up, 70.4% of all patients had complete resolution, whereas 19 patients had a partial resolution and 23 patients (19.5%) had stable disease. Monomorphic VTs and VTs with left bundle bunch block were more thriving controlled (p=0.02 vs. p=0.04). In terms of long-term results, no statistical difference was found among the VT groups (p=0.39). Deaths were observed only in IVT (n=1) and CMP-VT (n=8) groups (p<0.001), and the overall mortality rate of pediatric sustained VT was observed at 6.9% in this study. CONCLUSION VTs, which can cause sudden cardiac arrest, are potentially life-threatening arrhythmias. Identifying the heterogeneity of this VT and its peculiar characteristics would facilitate appropriate diagnosis and therapy.
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Sohinki DA, Mathew ST. Ventricular Arrhythmias in the Patient with a Structurally Normal Heart. J Innov Card Rhythm Manag 2018; 9:3338-3353. [PMID: 32477784 PMCID: PMC7252725 DOI: 10.19102/icrm.2018.091004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 02/04/2018] [Indexed: 11/24/2022] Open
Abstract
Ventricular arrhythmias (VAs) are among the most common cardiac rhythm disturbances encountered in clinical practice. Patients presenting with frequent ventricular ectopy or sustained ventricular tachycardia represent a challenging and worrisome clinical scenario for many practitioners because of concerning symptoms, frequent associated acute hemodynamic compromise, and the adverse prognostic implications inherent to these cases. While an underlying structural or functional cardiac abnormality, metabolic derangement, or medication toxicity is often readily apparent, many patients have no obvious underlying condition, despite a comprehensive diagnostic evaluation. Such patients are diagnosed as having an idiopathic VA, which is a label with specific implications regarding arrhythmia origin, prognosis, and potential for pharmacologic and invasive management. Further, a subset of patients with otherwise benign idiopathic ventricular ectopy can present with polymorphic ventricular tachycardia and ventricular fibrillation, adding a layer of complexity to a clinical syndrome previously felt to have a benign clinical course. Thus, this review seeks to highlight the most common types of idiopathic VAs with a focus on their prognostic implications, underlying electrophysiologic mechanisms, unique electrocardiographic signatures, and considerations for invasive electrophysiologic study and catheter ablation. We further address some of the data regarding idiopathic ventricular fibrillation with respect to the heterogeneous nature of this diagnosis.
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Affiliation(s)
- Daniel A Sohinki
- Department of Cardiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Sunil T Mathew
- Department of Cardiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Lam K. ECG Quiz. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790100800211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Kw Lam
- Kwong Wah Hospital, Accident and Emergency Department, 25 Waterloo Road, Kowloon, Hong Kong
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Hernandez-Cascales J. Resveratrol enhances the inotropic effect but inhibits the proarrhythmic effect of sympathomimetic agents in rat myocardium. PeerJ 2017; 5:e3113. [PMID: 28382232 PMCID: PMC5376116 DOI: 10.7717/peerj.3113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/21/2017] [Indexed: 01/01/2023] Open
Abstract
Background Resveratrol is a cardioprotective agent with known antiarrhythmic effects that has recently been shown to inhibit phosphodiesterase (PDE) enzyme activity. Thus, it is possible that resveratrol increases the inotropic effect of sympathomimetic agents, as PDE inhibitors do but, unlike other PDE inhibitors, its effect may not be accompanied by proarrhythmia due to its antiarrhythmic action. This work is aimed to test this hypothesis. Methods This is an “in vitro” concentration-response relationship study. The effects of noradrenaline, tyramine and isoproterenol, alone or in combination with either resveratrol or with the typical PDE inhibitor 3-isobutylmethylxantine (IBMX), were studied in electrically driven strips of right ventricle or in the spontaneously beating free wall of the right ventricle of rat heart in order to investigate inotropic or proarrhythmic effects respectively. Also, the effects of resveratrol or IBMX on the sinoatrial node rate were examined in the isolated right atria of rat heart. Results Resveratrol (10 µM and 100 µM) produces a leftward shift in the concentration-response curves for the contractile effects of noradrenaline, tyramine or isoproterenol and reduces the –log EC50 values of these three agents. IBMX produces similar effects. The spontaneous ventricular beating rate was increased by all three compounds, an effect that was further enhanced by the addition of IBMX. In contrast, resveratrol (100 µM) abolished the effects of these sympathomimetic agents on the ventricular rate. Resveratrol (1–100 µM) had no effect on the sinoatrial node rate, while IBMX produce a concentration dependent sinoatrial tachycardia. Discussion Taken together, the finding, indicate that resveratrol, like the PDE inhibitor IBMX enhances the contractile effects of sympathomimetic agents but, in contrast to IBMX, it does not enhance their proarrhythmic effect or produce sinoatrial tachycardia. This is most probably consequence of the antiarrhythmic effect of resveratrol which protect against the proarrhythmic effects resulting from PDE inhibition.
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Affiliation(s)
- Jesús Hernandez-Cascales
- Department of Pharmacology, Faculty of Medicine, University of Murcia , Espinardo-Murcia , Spain
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Dunbar CC, Kassotis JT, Heyda EK, Saul BI, Khan A, Gelles J. Repetitive Monomorphic Ventricular Tachycardia Associated with Exercise. Angiology 2016; 56:631-5. [PMID: 16193205 DOI: 10.1177/000331970505600517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The case of a 45-year-old man suffering from a catecholamine-sensitive ventricular tachycardia originating from the right ventricular outflow tract is reported. The authors describe a novel noninvasive treatment strategy for the management of this patient.
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Affiliation(s)
- Christopher C Dunbar
- Laboratory of Applied Physiology, Brooklyn College of the City University of New York, Brooklyn, NY, USA
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Marín JE, Díaz JC, García F, Velásquez JE, Aristizábal JM, Duque M, Uribe W. Capítulo 9. Ablación de extrasistolia ventricular y taquicardia ventricular en corazón sano. REVISTA COLOMBIANA DE CARDIOLOGÍA 2016. [DOI: 10.1016/j.rccar.2016.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Nogami A. Trigger elimination of polymorphic ventricular tachycardia and ventricular fibrillation by catheter ablation: trigger and substrate modification. J Biomed Res 2015; 29:44-51. [PMID: 25745474 PMCID: PMC4342434 DOI: 10.7555/jbr.29.20140156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/04/2014] [Indexed: 01/01/2023] Open
Abstract
Ventricular fibrillation (VF) is a malignant arrhythmia, usually initiated by a ventricular premature contraction (VPC) during the vulnerable period of cardiac repolarization. Ablation therapy for VF has been described and increasingly reported. Targets for VF triggers are VPCs preceded by Purkinje potentials or from the right ventricular outflow tract (RVOT) in structurally normal hearts, and VPC triggers preceded by Purkinje potentials in ischemic cardiomyopathy. During the session, mapping should be focused on the earliest activation and determining the earliest potential is the key to a successful ablation. However, suppression of VF can be achieved by not only the elimination of triggering VPCs, but also by substrate modification of possible reentry circuits in the Purkinje network, or between the PA and RVOT. The most important issue before the ablation session is the recording of the 12-lead ECG of the triggering event, which can prove invaluable in regionalizing the origin of the triggering VPC for more detailed mapping. In cases where the VPC is not spontaneous or inducible, ablation may be performed by pace mapping. Further studies are needed to evaluate the precise mechanisms of this arrhythmia.
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Affiliation(s)
- Akihiko Nogami
- Cardiovascular Division, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Verapamil-sensitive idiopathic left ventricular tachycardia in a 6-month-old: unique considerations in diagnosis and management in an infant. Pediatr Emerg Care 2015; 31:50-3. [PMID: 25526021 DOI: 10.1097/pec.0000000000000307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Idiopathic left ventricular tachycardia of the Belhassen type is rare in infants. We present a 6-month-old infant girl with a wide-complex tachycardia with right bundle branch block QRS morphology, a superior axis, and atrioventricular dissociation, consistent with a left anterior fascicular tachycardia. Initial echocardiogram revealed depressed ventricular function. The tachycardia was unresponsive to therapeutic trials of adenosine, esmolol, procainamide, and lidocaine. There was brief conversion of the tachycardia to sinus rhythm with transesophageal atrial overdrive pacing, suggesting a reentrant mechanism of the arrhythmia. Ultimately, the judicious administration of intravenous verapamil resulted in termination of the arrhythmia, which has been sustained on oral therapy.
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Rillig A, Lin T, Ouyang F, Kuck KH, Tilz RR. Which Is The Appropriate Arrhythmia Burden To Offer RF Ablation For RVOT Tachycardias? J Atr Fibrillation 2014; 7:1157. [PMID: 27957135 DOI: 10.4022/jafib.1157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/12/2013] [Accepted: 02/12/2013] [Indexed: 12/14/2022]
Abstract
Premature ventricular complexes (PVCs) and ventricular tachycardia (VT) in patients with structurally normal hearts originate from the right ventricular outflow tract (RVOT) in the majority of cases. In the last few decades catheter ablation of these arrhythmias has been proven to be effective. RVOT VT/PVCs may cause disabling symptoms or arrhythmia induced cardiomyopathy. However, the PVC burden at which catheter ablation should be recommended is still controversial. What adds to the controversy is why some patients with only a low number of PVCs can be highly symptomatic and may even develop arrhythmia induced cardiomyopathy, whilst others may have a higher PVC/VT burden and remain asymptomatic and do not develop cardiomyopathy for a long period of time. Therefore, although catheter ablation of RVOT PVCs has high success and low complication rates, the time point of when ablation should be recommended is currently still under debate. This review discusses the treatment strategies and prognosis for RVOT tachycardias and focuses on the question of which arrhythmia burden is appropriate to offer RF ablation.
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Affiliation(s)
- Andreas Rillig
- Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany
| | - Tina Lin
- Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany
| | - Feifan Ouyang
- Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany
| | - Karl-Heinz Kuck
- Department of Cardiology, Asklepios Klinik St. Georg, Hamburg, Germany
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Crosson JE, Callans DJ, Bradley DJ, Dubin A, Epstein M, Etheridge S, Papez A, Phillips JR, Rhodes LA, Saul P, Stephenson E, Stevenson W, Zimmerman F. PACES/HRS expert consensus statement on the evaluation and management of ventricular arrhythmias in the child with a structurally normal heart. Heart Rhythm 2014; 11:e55-78. [PMID: 24814375 DOI: 10.1016/j.hrthm.2014.05.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Indexed: 01/02/2023]
Affiliation(s)
- Jane E Crosson
- Bloomberg Children's Center, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David J Callans
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Anne Dubin
- Lucile Packard Children's Hospital, Stanford School of Medicine, Stanford, California
| | | | - Susan Etheridge
- University of Utah and Primary Children's Medical Center, Salt Lake City, Utah
| | - Andrew Papez
- Phoenix Children's Hospital/Arizona Pediatric Cardiology Consultants Phoenix, Arizona
| | | | | | - Philip Saul
- Nationwide Children's Hospital, Ohio State University, Columbus, Ohio
| | | | - William Stevenson
- Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Frank Zimmerman
- Advocate Heart Institute for Children Advocate Children's Hospital, Oak Lawn, Illinois.
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Gangadharan V, Sharma D, Ramu V, Paul T. Too much exercise: right ventricular outflow tract tachycardia. Am J Med 2014; 127:205-8. [PMID: 24321412 DOI: 10.1016/j.amjmed.2013.11.008] [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] [Received: 05/09/2013] [Revised: 11/26/2013] [Accepted: 11/26/2013] [Indexed: 11/16/2022]
Affiliation(s)
| | - Dinesh Sharma
- Department of Cardiology, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Vijay Ramu
- Department of Cardiology, Quillen College of Medicine, East Tennessee State University, Johnson City
| | - Timir Paul
- Department of Cardiology, Quillen College of Medicine, East Tennessee State University, Johnson City
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Ghanbari H, Schmidt M, Machado C, Daccarett M. Catheter ablation of ventricular tachycardia in structurally normal hearts. Expert Rev Cardiovasc Ther 2014; 8:651-61. [DOI: 10.1586/erc.10.25] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Tilz RR, Lin T, Makimoto H, Ouyang F. Successful epicardial ablation of electrical storms due to recurrent ventricular fibrillation triggered by premature ventricular contractions. Heart Rhythm 2013; 11:146-9. [PMID: 24103223 DOI: 10.1016/j.hrthm.2013.10.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Indexed: 11/17/2022]
Affiliation(s)
| | - Tina Lin
- Asklepios Klinik, St. Georg, Hamburg, Germany
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Sellal JM, Brembilla-Perrot B, Suty-Selton C, Sadoul N, Huttin O. Ventricular tachycardia without apparent heart disease: long-term follow-up. J Electrocardiol 2011; 44:786-91. [PMID: 21419424 DOI: 10.1016/j.jelectrocard.2011.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Indexed: 11/28/2022]
Abstract
UNLABELLED The purpose of the study was to evaluate the long-term prognosis of ventricular tachycardia (VT) in patients without structural heart disease (HD). METHODS Holter monitoring, exercise test, echocardiography, right angiography, coronary angiography, and electrophysiologic study were performed in 810 patients with VT. RESULTS Eighty patients (mean age, 45 ± 17 years) had no apparent HD. VT was reproduced at electrophysiologic study in 62 patients. Mean follow-up was 9.7 ± 7 years. Initially, 91% were treated with drugs. Defibrillator was implanted in 4, including 2 for arrhythmogenic right ventricular cardiomyopathy diagnosed later. VT ablation was performed in 3 patients. Three patients older than 70 years died of nonarrhythmic cause. Other patients are alive without antiarrhythmic drug treatment in 50%. Three developed a dilated cardiomyopathy; and 2, atrial fibrillation. CONCLUSIONS Invasive treatment was rarely required in patients with VT without HD. The prognosis was only dependent on the age and the pattern of electrocardiogram in VT.
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Hu X, Wang J, Xu C, He B, Lu Z, Jiang H. Effect of oestrogen replacement therapy on idiopathic outflow tract ventricular arrhythmias in postmenopausal women. Arch Cardiovasc Dis 2011; 104:84-8. [DOI: 10.1016/j.acvd.2010.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/21/2010] [Accepted: 11/24/2010] [Indexed: 11/30/2022]
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Hu X, Jiang H, Xu C, Zhou X, Cui B, Lu Z. Relationship between sex hormones and idiopathic outflow tract ventricular arrhythmias in adult male patients. Transl Res 2009; 154:265-8. [PMID: 19840768 DOI: 10.1016/j.trsl.2009.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/22/2009] [Accepted: 07/20/2009] [Indexed: 11/18/2022]
Abstract
Sex hormones and gender differences have been reported to be associated with the occurrences of ventricular arrhythmias. This study investigated the relationship between sex hormones and idiopathic outflow tract ventricular arrhythmias (IOTVA) in adult male patients. Serum sex hormonal levels, which include testosterone, estradiol, and progestogen, were measured by using commercially prepared immunoassay kits. The average count of premature ventricular contractions (PVCs) (number/24h) was assessed by 72h electrocardiographic monitoring. No differences were found in the levels of testosterone and progestogen between the IOTVA male patients and the control males (both P>0.05). However, the level of estradiol in the IOTVA male patients was significantly lower than that in the control males (P<0.05). A significant negative correlation was observed between the number of PVCs and the level of estradiol in the IOTVA male patients (r=0.702, P<0.05). The current study suggested that IOTVA might be associated with the reduction of estradiol level in adult male patients.
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Affiliation(s)
- Xiaorong Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute of Wuhan University, Wuhan, China
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Srivathsan K, Ng DWC, Mookadam F. Ventricular tachycardia and ventricular fibrillation. Expert Rev Cardiovasc Ther 2009; 7:801-9. [PMID: 19589116 DOI: 10.1586/erc.09.69] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ventricular tachycardia and ventricular fibrillation are the most important causes of sudden cardiac death (SCD), particularly in those with structural heart disease and reduced left ventricular function. It is important to distinguish ventricular tachycardia from supraventricular tachycardia. A wide spectrum of ventricular arrhythmias exists, from those where the heart is structurally normal to those with structural heart disease. Each entity has a distinctive pathophysiology, treatment plan and prognostic outcome. Treatment modalities include simple beta-blockade to implantation of implantable cardiac defibrillator and ablative approaches. In general, those ventricular arrhythmias associated with a structurally normal heart are more benign than those associated with structural heart disease.
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Neiger JS, Gupta A, Halleran SM, Trohman RG. Magnesium sensitive, adenosine resistant, repetitive monomorphic ventricular tachycardia. Pacing Clin Electrophysiol 2009; 32:e28-30. [PMID: 19744277 DOI: 10.1111/j.1540-8159.2009.02527.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Repetitive monomorphic ventricular tachycardia (RMVT) is characterized by episodes of ventricular ectopy and nonsustained VT exacerbated by catecholamines. Because this arrhythmia is frequently adenosine sensitive, its mechanism is believed to be cyclic adenosine monophosphate-mediated triggered activity due to delayed afterdepolarizations. We present a case of RMVT associated with significant hypomagnesemia (serum level = 1.1 mg/dL), which did not respond to intravenous (IV) adenosine and terminated repeatedly after IV magnesium. Electrophysiologic study demonstrated an origin from the left sinus of Valsalva, which was successfully ablated. The combination of adenosine resistance and magnesium sensitivity may be consistent with an atypical RMVT mechanism related to inhibition of sodium-potassium adenosine triphosphatase (Na(+)-K(+) ATPase).
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Affiliation(s)
- Jeffrey S Neiger
- Department of Medicine, Section of Cardiology, Clinical Cardiac Electrophysiology Service, Rush University Medical Center, Chicago, Illinois, USA
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Abstract
Many sets of guidelines written by experts in their fields can assist sports medicine physicians to make return-to-play decisions for athletes with known or suspected cardiac conditions. These guidelines can be divided into pre-participation screening guidelines, such as the 2007 American Heart Association (AHA) 12-element screening examination, and specific recommendations for those with heart disease or symptoms. Several important documents fall into the latter category. Among these are the 36th Bethesda Guidelines, the European Society of Cardiology Guidelines, the AHA Consensus Document for Young People with Genetic Conditions, the Heart Rhythm Society Guidelines, and the Guidelines for Masters Athletes. Guidelines are designed to enhance the sports medicine physician's probability of detecting heart disease and making wise participation and return-to-play decisions in athletes with high-risk cardiac conditions, such as hypertrophic cardiomyopathy, anomalous coronary artery, myocarditis, and valvular heart disease. Guidelines also aid in writing exercise prescriptions for those deemed too high risk for sports participation. Because the guidelines may not be entirely consistent on all topics, or based on opinion rather than research evidence, many cases require additional input from a cardiologist or electrophysiologist. Guidelines address not only specific disease entities, but also how corrective surgery, ablations, implantable defibrillators, or drug therapy can influence return-to-play decisions. They are updated as new studies become available to provide physicians with the most up-to-date information.
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Mustafa SJ, Morrison RR, Teng B, Pelleg A. Adenosine receptors and the heart: role in regulation of coronary blood flow and cardiac electrophysiology. Handb Exp Pharmacol 2009:161-88. [PMID: 19639282 PMCID: PMC2913612 DOI: 10.1007/978-3-540-89615-9_6] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
Adenosine is an autacoid that plays a critical role in regulating cardiac function, including heart rate, contractility, and coronary flow. In this chapter, current knowledge of the functions and mechanisms of action of coronary flow regulation and electrophysiology will be discussed. Currently, there are four known adenosine receptor (AR) subtypes, namely A(1), A(2A), A(2B), and A(3). All four subtypes are known to regulate coronary flow. In general, A(2A)AR is the predominant receptor subtype responsible for coronary blood flow regulation, which dilates coronary arteries in both an endothelial-dependent and -independent manner. The roles of other ARs and their mechanisms of action will also be discussed. The increasing popularity of gene-modified models with targeted deletion or overexpression of a single AR subtype has helped to elucidate the roles of each receptor subtype. Combining pharmacologic tools with targeted gene deletion of individual AR subtypes has proven invaluable for discriminating the vascular effects unique to the activation of each AR subtype. Adenosine exerts its cardiac electrophysiologic effects mainly through the activation of A(1)AR. This receptor mediates direct as well as indirect effects of adenosine (i.e., anti-beta-adrenergic effects). In supraventricular tissues (atrial myocytes, sinuatrial node and atriovetricular node), adenosine exerts both direct and indirect effects, while it exerts only indirect effects in the ventricle. Adenosine exerts a negative chronotropic effect by suppressing the automaticity of cardiac pacemakers, and a negative dromotropic effect through inhibition of AV-nodal conduction. These effects of adenosine constitute the rationale for its use as a diagnostic and therapeutic agent. In recent years, efforts have been made to develop A(1)R-selective agonists as drug candidates that do not induce vasodilation, which is considered an undesirable effect in the clinical setting.
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Affiliation(s)
- S Jamal Mustafa
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV 26505-9229, USA.
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23
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Kumar R, Ramachandraiah CT, Chokka P, Yeragani VK. Mean and variability of QT-interval: Relevance to psychiatric illness and psychotropic medication. Indian J Psychiatry 2009; 51:6-8. [PMID: 19742196 PMCID: PMC2738406 DOI: 10.4103/0019-5545.44898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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24
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25
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Sanatani S, Duncan W, Chan S. The challenge of diagnosing arrhythmogenic right ventricular cardiomyopathy in the young. Pediatr Cardiol 2008; 29:800-3. [PMID: 18427879 DOI: 10.1007/s00246-008-9238-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 04/03/2008] [Indexed: 11/26/2022]
Abstract
We report two cases of arrhythmogenic right ventricular cardiomyopathy (ARVC) in the pediatric age group. In both cases, the diagnosis was considered and pursued but would not be made utilizing Task Force Criteria. The diagnosis was made based on the morphology of a single beat during exercise testing. We illustrate the difficulty of diagnosing ARVC in the young even with a heightened index of suspicion.
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Affiliation(s)
- Shubhayan Sanatani
- Division of Pediatric Cardiology, Department of Pediatrics, University of British Columbia, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
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26
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Murphy J, Slodzinski M. Right ventricular outflow tract tachycardia in the parturient. Int J Obstet Anesth 2008; 17:275-8. [PMID: 18511258 DOI: 10.1016/j.ijoa.2007.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 09/01/2007] [Indexed: 10/22/2022]
Abstract
Parturition is marked by physiological changes that may elicit electrocardiographic anomalies. Sustained right ventricular tachycardia is an uncommon arrhythmia that necessitates cardioversion using physical, pharmaceutical or electrical means. Patients with right ventricular tachycardia must be evaluated for right ventricular dysplasia. Long-term management of right ventricular tachycardia includes beta-adrenergic blockade and/or radio ablation of right ventricle outflow region usually below the pulmonary annuls. This report discusses the case of a 28-year-old previously healthy primigravid who experienced right ventricular outflow tract tachycardia during labor.
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Affiliation(s)
- J Murphy
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA
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27
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Goldberger ZD, Rho RW, Page RL. Approach to the diagnosis and initial management of the stable adult patient with a wide complex tachycardia. Am J Cardiol 2008; 101:1456-66. [PMID: 18471458 DOI: 10.1016/j.amjcard.2008.01.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 01/16/2008] [Accepted: 01/16/2008] [Indexed: 11/29/2022]
Abstract
The initial electrocardiographic evaluation of every tachyarrhythmia should begin by addressing the question of whether the QRS complex is wide or narrow. The most important cause of wide complex tachycardia (WCT) is ventricular tachycardia. However, supraventricular tachycardia can also manifest with a wide QRS complex. The ability to differentiate between supraventricular tachycardia with a wide QRS due to aberrancy or preexcitation and ventricular tachycardia often presents a diagnostic challenge. The identification of whether WCT has a ventricular or supraventricular origin is critical because the treatment for each is different, and improper therapy may have potentially lethal consequences. In conclusion, although the diagnosis and treatment of sustained WCT often arise in emergency situations, this report focuses on a stepwise approach to the management of WCT in relatively stable adult patients, particularly the diagnosis and differentiation of ventricular tachycardia from supraventricular tachycardia with a wide QRS complex on standard 12-lead electrocardiography.
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Affiliation(s)
- Zachary D Goldberger
- Department of Internal Medicine, University of Washington Medical Center, VA Puget Sound Health Care System, Seattle, Washington, USA.
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28
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Abstract
PATIENTS We report on a 6-month-old patient with a right bundle, superior axis tachycardia at 197 beats per minute. The tachycardia was unresponsive to adenosine, propranolol, flecainide, or amiodarone, or synchronized cardioversion. Overdrive atrial pacing terminated the tachycardia and since initiating verapamil, no recurrences of his tachycardia have occurred. CONCLUSIONS If an infant presents with a right bundle, superior axis ventricular tachycardia unresponsive to multiple antiarrhythmic medications and synchronized cardioversion, but responsive to overdrive atrial pacing, one must consider verapamil-sensitive ventricular tachycardia and initiate appropriate therapy.
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Affiliation(s)
- Christopher Snyder
- Ochsner Clinic Foundation-Pediatric Cardiology, New Orleans, LA 70121, USA.
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29
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30
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Khraisat A, Singh S, Arora R, Al-Jaghbeer E. A heart aflutter. Am J Med 2007; 120:857-9. [PMID: 17904455 DOI: 10.1016/j.amjmed.2007.07.006] [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] [Received: 02/09/2007] [Revised: 07/02/2007] [Accepted: 07/02/2007] [Indexed: 11/29/2022]
Affiliation(s)
- Ahmad Khraisat
- Section of Cardiology, Department of Medicine, The Chicago Medical School, North Chicago, IL 60064, USA.
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31
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Shin SY, Joo HJ, Kim JH, Jang JK, Park JS, Kim YH, Lee HS, Choi JI, Lim HE, Kim YH. Epicardial Conduction Properties and Electrocardiographic Characteristics of Premature Ventricular Complexes or Ventricular Tachycardias That Originate at the Aortic Cusp. Korean Circ J 2007. [DOI: 10.4070/kcj.2007.37.12.616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Seung-Yong Shin
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Hyung-Joon Joo
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Ji-Hoon Kim
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Jin-Kun Jang
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Jae-Seok Park
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Yong-Hyun Kim
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Hyun-Soo Lee
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Jong-Il Choi
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Hong-Euy Lim
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
| | - Young-Hoon Kim
- Division of Cardiology, Department of Internal Medicine, Korea University Medical Center, Anam Hospital, Seoul, Korea
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32
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Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G, Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy C, Smith SC, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA, Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Priori SG, Blanc JJ, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL, Zamorano JL. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). J Am Coll Cardiol 2006; 48:e247-346. [PMID: 16949478 DOI: 10.1016/j.jacc.2006.07.010] [Citation(s) in RCA: 867] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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33
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Zipes DP, Camm AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G, Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy C, Smith SC, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA, Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Blanc JJ, Budaj A, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL, Zamorano JL. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation 2006; 114:e385-484. [PMID: 16935995 DOI: 10.1161/circulationaha.106.178233] [Citation(s) in RCA: 807] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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34
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Yarlagadda RK, Iwai S, Stein KM, Markowitz SM, Shah BK, Cheung JW, Tan V, Lerman BB, Mittal S. Reversal of Cardiomyopathy in Patients With Repetitive Monomorphic Ventricular Ectopy Originating From the Right Ventricular Outflow Tract. Circulation 2005; 112:1092-7. [PMID: 16103234 DOI: 10.1161/circulationaha.105.546432] [Citation(s) in RCA: 300] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Tachycardia-induced cardiomyopathy caused by ventricular tachycardia is a well-defined clinical entity. Less well appreciated is whether simple ventricular ectopy can result in cardiomyopathy. We sought to examine a potential causal relationship between repetitive monomorphic ventricular ectopy originating from the right ventricular outflow tract and cardiomyopathy and the role of ablation in reversing this process.
Methods and Results—
The study consisted of 27 patients (11 men; age, 47±15 years) with repetitive monomorphic ventricular ectopy, including 8 patients (30%) with depressed ventricular function (ejection fraction ≤45%). All patients underwent assessment of cardiac structure and function. The burden of ectopy was quantified through 24-hour Holter monitoring. Patients then underwent ablation guided by 3D mapping. After ablation, patients underwent repeated Holter monitoring and reassessment of cardiac function. Patients with depressed ventricular function were more likely to be older than patients with normal function (58±14 versus 42±18 years;
P
=0.013). However, the burden of ventricular ectopy was similar in patients with (17 859±13 488 ectopic beats per 24 hours) and without (17 541±11 479 ectopic beats per 24 hours;
P
=0.800) preserved ventricular function. Successful ablation was performed in 23 patients (85%), including 7 of 8 patients with depressed ventricular function. In this latter group, ventricular function improved in all patients (from 39±6% to 62±6%;
P
=0.017).
Conclusions—
Repetitive monomorphic ventricular ectopy (in the absence of sustained ventricular tachycardia) originating from the right ventricular outflow tract is an underappreciated cause of unexplained cardiomyopathy. Successful ablation of the focal source of ventricular ectopy results in normalization of left ventricular function. Patients with ectopy-induced cardiomyopathy are significantly older than patients with preserved ventricular function, which suggests either that older patients are more susceptible to the development of a cardiomyopathy or that the cardiomyopathy has had a longer period of time in which to evolve.
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Affiliation(s)
- Ravi K Yarlagadda
- Maurice and Corinne Greenberg Division of Cardiology, Cornell University Medical Center, New York, NY 10021, USA
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35
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Castaneda MP, Walsh CA, Woroniecki RP, Del Rio M, Flynn JT. Ventricular arrhythmia following short-acting nifedipine administration. Pediatr Nephrol 2005; 20:1000-2. [PMID: 15880273 DOI: 10.1007/s00467-005-1854-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 12/21/2004] [Accepted: 12/21/2004] [Indexed: 10/25/2022]
Abstract
Short-acting nifedipine is still advocated for use in children with severe hypertension, but is no longer recommended for use in adults because of adverse effects from rapid blood pressure reduction. A 19 year-old adolescent with symptomatic, severe hypertension (blood pressure 180/120) received 10 mg of short-acting nifedipine sublingually for blood pressure reduction. Within minutes after the dose, the patient complained of palpitations. Tachycardia (heart rate 100 beats per minute) and bigeminy were noted on the cardiac monitor. The bigeminy resolved but premature ventricular contractions were noted for the duration of her hospital stay. We hypothesize that reflex sympathetic activation following an abrupt drop in blood pressure may cause arrhythmias because of elevated catecholamine levels. Given this, it may be more appropriate to treat severe hypertension in children with intravenous antihypertensive agents that can be titrated to produce controlled reductions in blood pressure.
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Affiliation(s)
- M Patricia Castaneda
- Division of Pediatric Nephrology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA
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36
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Abstract
Idiopathic ventricular tachycardia in patients with an anatomically normal heart is a distinct entity whose management and prognosis differs from ventricular tachycardia associated with structural heart disease. The tachycardia's QRS morphology on surface electrocardiogram (ECG) predicts the site of origin and is commonly classified as right ventricular tachycardia or left ventricular tachycardia. The tachycardia is further characterized by clinical features such as repetitive monomorphic ventricular tachycardia (VT), paroxysmal sustained VT, or catecholamine dependent VT. The responsiveness of VT to adenosine or verapamil is useful in differentiating the mechanism, which may be reentry or triggered activity. Patients generally tolerate the tachycardia but may present with dizziness, syncope, or palpitations. Sudden cardiac death is rare in this patient population. Patient work-up should include 12-lead ECG, signal-averaged ECG, ambulatory ECG recording, stress testing, and tests to rule out structural heart disease such as echocardiography, cardiac angiography, endomyocardial biopsy, or magnetic resonance imaging. Treatment options include pharmacotherapy or catheter ablation. Although the prognosis of these patients remains excellent, they should continue to have periodic cardiac follow-up to rule out latent progressive heart disease such as arrhythmogenic right ventricular dysplasia or cardiomyopathy or other forms of cardiomyopathies.
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37
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Kies P, Wichter T, Schäfers M, Paul M, Schäfers KP, Eckardt L, Stegger L, Schulze-Bahr E, Rimoldi O, Breithardt G, Schober O, Camici PG. Abnormal Myocardial Presynaptic Norepinephrine Recycling in Patients With Brugada Syndrome. Circulation 2004; 110:3017-22. [PMID: 15520312 DOI: 10.1161/01.cir.0000146920.35020.44] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Background—
Life-threatening ventricular tachyarrhythmias can occur in young patients without structural heart disease (idiopathic forms). In many patients, these are typically triggered by an increased sympathetic tone, eg, by physical or mental stress. In contrast, in Brugada syndrome, ventricular tachyarrhythmias more often occur during rest or sleep when the vagal tone is predominant. Furthermore, adrenergic agonists can reduce the level of ST-segment elevation, whereas it is increased by parasympathetic agonists or adrenergic antagonists. The aim of this study was to investigate presynaptic and postsynaptic myocardial sympathetic function in patients with Brugada syndrome.
Methods and Results—
Nine patients with Brugada syndrome (6 male, 3 female; age, 41±13 years) were enrolled in this study. The cardiac autonomic nervous system was assessed noninvasively, quantifying myocardial presynaptic and postsynaptic sympathetic function by means of positron emission tomography with the norepinephrine analogue
11
C-Hydroxyephedrine (
11
C-HED) and the nonselective β-blocker
11
C-CGP 12177 (
11
C-CGP). Presynaptic sympathetic norepinephrine recycling, assessed by
11
C-HED, was globally increased in patients with Brugada syndrome compared with a group of age-matched healthy control subjects (92.9±16.2 mL/g versus 69.1±14.2 mL/g;
P
<0.05), whereas postsynaptic β-adrenoceptor density, assessed by
11
C-CGP, was similar in patients and control subjects (10.4±6.7 pmol/g versus 10.2±2.9 pmol/g;
P
=NS).
Conclusions—
The present study on autonomic innervation in Brugada syndrome describes an enhanced presynaptic norepinephrine recycling with preserved β-adrenoceptor density, further supporting the hypothesis of an autonomic dysfunction in Brugada syndrome. This is a further step toward the understanding of the pathophysiology of the disease with potential future impact on therapeutic strategies.
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Affiliation(s)
- Peter Kies
- Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Str 33, D-48149 Münster, Germany.
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38
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Wang JD, Fu YC, Jan SL, Chi CS. Verapamil Sensitive Idiopathic Ventricular Tachycardia in an Infant. ACTA ACUST UNITED AC 2003; 44:667-71. [PMID: 14587648 DOI: 10.1536/jhj.44.667] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Idiopathic ventricular tachycardia is rare, especially in infants. We report here on an 8 month-old female infant who presented with tachycardia with a heart rate of 186 beats/ min. An electrocardiogram showed a right bundle branch block pattern, a QRS duration of 80 msec, a superior QRS axis, atrioventricular dissociation, and occasional fusion and capture beats. Suspected ventricular tachycardia was treated with lidocaine, propranolol and amiodarone, but in vain. The tachycardia was terminated and well controlled with the use of verapamil. According to an electrocardiogram and her clinical response, verapamil-sensitive idiopathic ventricular tachycardia was diagnosed with the arrhythmic origin in the left posterior fascicle.
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Affiliation(s)
- Jiaan-Der Wang
- Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China
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39
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Abstract
This review focuses on four distinct syndromes of ventricular tachycardia that occur in the structurally normal heart. Recent advances in the fields of molecular biology and genetics, along with intracardiac mapping techniques, have led to a greater understanding of the underlying mechanisms of and therapeutic options for these syndromes. The cyclic AMP-mediated triggered activity tachycardias, including exercise-induced right ventricular outflow track tachycardia and repetitive monomorphic ventricular tachycardia, are the most common of these syndromes. Idiopathic left ventricular tachycardia, for which there is significant evidence for re-entry within the Purkinje network, is largely curable with catheter ablation. The long QT syndrome comprises a heterogeneous group of ion channel defects leading to prolongation of myocyte repolarization and Torsade de Pointes ventricular tachycardia. Brugada syndrome, a familial disorder of transmembrane ion transport, is felt to be the result of a group of sodium channel defects leading to characteristic electrocardiographic abnormalities, and syncope and sudden death. Primary focus is given to recent advances in our understanding of the underlying mechanism and current therapeutic approaches.
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Affiliation(s)
- T Scott Wall
- University of Utah Medical Center, Division of Cardiology, 50 North Medical Drive, Salt Lake City, UT 84132, USA
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40
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Harada T, Tomotake M, Ohkubo A, Nishikado A, Yamamoto T, Wakatsuki T, Ohmori T. Radiofrequency catheter ablation enabled antipsychotic treatment in a schizophrenic patient with idiopathic ventricular tachycardia. Gen Hosp Psychiatry 2002; 24:277-8. [PMID: 12100841 DOI: 10.1016/s0163-8343(02)00187-1] [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: 12/01/2022]
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41
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Safi AM, Chaudhry K, Stein RA. Multi-morphology wide QRS tachycardias in a patient without structural heart disease: an unusual presentation of ventricular tachycardia. JAPANESE HEART JOURNAL 2001; 42:633-8. [PMID: 11804305 DOI: 10.1536/jhj.42.633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ventricular tachycardia occurs infrequently in patients without structural heart disease. These tachycardias commonly originate from the right ventricular outflow tract. However, the presence of more than one arrhythmogenic substrate in a patient without structural heart disease is rare. We report such a 48-year old patient with no structural heart disease who presented with three morphology wide QRS tachycardia. A brief review of the pathophysiology and management is discussed.
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Affiliation(s)
- A M Safi
- Department of Medicine, The Brooklyn Hospital Center, New York 11201, USA
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42
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Zhang YH, Hinde AK, Hancox JC. Anti-adrenergic effect of adenosine on Na(+)-Ca(2+) exchange current recorded from guinea-pig ventricular myocytes. Cell Calcium 2001; 29:347-58. [PMID: 11292391 DOI: 10.1054/ceca.2001.0197] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Na(+)-Ca(2+) exchanger is a protein present in the cell membrane of many cell types. In heart it plays important roles in Ca homeostasis and ionic current generation. Recently, it has been reported that the beta-adrenergic agonist isoprenaline (ISO) can increase directly Na(+)-Ca(2+) exchanger activity in guinea-pig ventricular myocytes. Adenosine (ADO) exerts anti-adrenergic properties that make it effective against some arrhythmias and the aim of the present study was to determine whether or not ADO can antagonize the direct modulatory effect of ISO on the exchanger.Whole-cell patch clamp measurements of Na(+)-Ca(2+) exchanger current (I(NaCa)) were made from guinea-pig ventricular myocytes, with major interfering currents inhibited. I(NaCa) was measured at 378 degrees C as current sensitive to external nickel (Ni(2+), 10 mM) during an applied descending voltage ramp. ISO (1 microM) significantly increased both inward and outward I(NaCa). This effect was abolished in the presence of ADO (200 microM). ADO alone did not significantly alter the amplitude of I(NaCa). The effect of ADO on the response of I(NaCa) to ISO was mimicked by the A(1)ADO receptor agonist N(6)-cyclopentyladenosine (CPA, 10 microM), whereas the effect of ADO on the response of I(NaCa) to ISO was inhibited by the A(1)ADO receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 microM). These data suggest that the A(1)ADO receptor mediated the response. The anti-adrenergic effects on I(NaCa) of ADO were not affected by the protein kinase C (PKC) inhibitor, chelerythrine (CLT, 1 microM), nor by the nitric oxide (NO) synthase inhibitor, N (G)-nitro-L-arginine methyl ester((L)-NAME, 0.5 mM). Moreover, in the presence of PKC activator phorbol 12-myristate 13-acetate (PMA, 1 microM) or exogenous NO donor sodium nitroprusside (SNP, 100 microM), ISO preserved its stimulatory effect on I(NaCa). However, prior incubation of myocytes with pertussis toxin (PTX, 5 microg ml(-1) did prevent the effect of ADO. The anti-adrenergic effect of ADO on I(NaCa) was mimicked by externally applied carbachol (CCh, 10 microM), a muscarinic receptor agonist. We conclude that ADO antagonized the effect of beta-adrenergic stimulation of I(NaCa) by directly activating inhibitory G-protein (G(i))-linked A(1) receptors in guinea-pig ventricular myocytes. These findings may suggest a novel mechanism by which adenosine exerts some of its antiarrhythmic effects.
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Affiliation(s)
- Y H Zhang
- Department of Physiology and Cardiovascular Research Laboratories, School of Medical Sciences, Bristol, UK
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43
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Abstract
Ventricular tachyarrhythmias secondary to a variety of underlying cardiovascular problems pose a therapeutic challenge to the clinician. The initial presentation may be as sudden cardiac death, which underlies its public health problem. The underlying conditions predisposing to this arrhythmia include ischemic heart disease, dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmiogenic right ventricle dysplasia and certain postoperative states including corrective surgery for tetralogy of Fallot and valve replacement. Other causes include prolonged QT syndrome, idiopathic right and left ventricle tachycardia and bundle branch re-entry tachycardia. Ischaemic heart disease is the most common cause of ventricular tachycardia and therapy has evolved considerably over the past two decades. The development of and refinements in the implantable cardioverter-defibrillator (ICD) have introduced a new dimension in therapeutic options and markedly improved survival in these patients. Insights in the dichotomy between arrhythmia suppression and total mortality have reoriented drug therapy with a decrease in the use of sodium channel blockers. beta-blockers have emerged as antiarrhythmic drugs in their own right and their synergistic effects with amiodarone have strengthened the antiarrhythmic drug arm. The role of these drugs in patients with hemodynamically stable ventricular tachycardia, especially in relatively preserved ventricles needs to be explored. Catheter ablation techniques have provided curative therapy in patients with idiopathic and bundle branch reentry tachycardia. Further advances in radiofrequency ablation, including use of newer mapping techniques, promise a greater role for ablation of ischemic ventricular tachycardia in the future. A hybrid approach consisting of drugs, catheter ablation and/ or ICD may provide effective therapeutic approach in some situations. Further innovations and technologic developments promise a further reorientation in therapy towards identification and treatment of the underlying arrhythmogenic substrate.
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Affiliation(s)
- K K Talwar
- Department of Cardiology, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
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44
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Abstract
The majority of patients who present with ventricular tachycardia have underlying structural heart disease. However, there has been increasing appreciation of the existence of multiple forms of idiopathic ventricular tachycardia with distinct features and unique mechanisms. The most common form of idiopathic ventricular tachycardia originates from the right ventricular outflow tract, is characterized by sensitivity to adenosine, and appears to be due to cyclic AMP-mediated triggered activity. Other forms of idiopathic ventricular tachycardia include intrafascicular left ventricular tachycardia, due to reentry, which is sensitive to verapamil, and automatic, propranolol-sensitive ventricular tachycardia.
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Affiliation(s)
- S Iwai
- Department of Medicine, Division of Cardiology, The New York Hospital-Cornell University Medical Center, 525 East 68th Street, Starr 409, New York, NY 10021, USA
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