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Boulay E, Miraucourt LS, Pugsley MK, Abernathy MM, Chui R, Dalton J, Demers M, Dybdal N, Gazaille E, Greiter-Wilke A, Hoffmann P, Huang H, LaDuke C, Norton K, Pierson JB, Reeves I, Roche B, Rossman EI, Schultze AE, Tang HM, Wisialowski T, Authier S. The incidence of spontaneous arrhythmias in telemetered beagle dogs, Göttingen Minipigs and Cynomolgus non-human primates: A HESI consortium retrospective analysis. J Pharmacol Toxicol Methods 2023; 121:107266. [PMID: 36963703 DOI: 10.1016/j.vascn.2023.107266] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/26/2023]
Abstract
INTRODUCTION Characterization of the incidence of spontaneous arrhythmias to identify possible drug-related effects is often an important part of the analysis in safety pharmacology studies using telemetry. METHODS A retrospective analysis in non-clinical species with and without telemetry transmitters was conducted. Electrocardiograms (24 h) from male and female beagle dogs (n = 131), Göttingen minipigs (n = 108) and cynomolgus non-human primates (NHP; n = 78) were analyzed. RESULTS Ventricular tachycardia (VT) was observed in 3% of the dogs but was absent in minipigs and NHPs. Ventricular fibrillation (VF) was not observed in the 3 species. Ventricular premature beats (VPBs) were more frequent during daytime and atrioventricular blocks (AVBs) were more frequent at night in all species. A limited number of animals exhibited a high arrhythmia frequency and there was no correlation between animals with higher frequency of an arrhythmia type and the frequency of other arrythmias in the same animals. Clinical chemistry or hematology parameters were not different with or without telemetry devices. NHP with a transmural left ventricular pressure (LVP) catheter exhibited a greater incidence of VPBs and PJCs compared to telemetry animals without LVP. DISCUSSION All species were similar with regards to the frequency of ventricular ectopic beats (26-46%) while the dog seemed to have more frequent junctional complexes and AVB compared to NHP and minipigs. Arrhythmia screening may be considered during pre-study evaluations, to exclude animals with abnormally high arrhythmia incidence.
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Affiliation(s)
- Emmanuel Boulay
- Charles River, Laval, Canada; Faculty of Veterinary Medicine, University of Montreal, QC, Canada
| | | | | | | | - Ray Chui
- Cardiovascular Analytics, Newbury Park, CA, USA
| | | | - Marjorie Demers
- Faculty of Veterinary Medicine, University of Montreal, QC, Canada
| | | | - Elissa Gazaille
- Faculty of Veterinary Medicine, University of Montreal, QC, Canada
| | - Andrea Greiter-Wilke
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center, Basel, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | - Simon Authier
- Charles River, Laval, Canada; Faculty of Veterinary Medicine, University of Montreal, QC, Canada.
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Haum M, Kellnar A, Thienel M, Lackermair K. Review: Sex-related differences in the treatment of cardiac arrhythmia. Pharmacol Ther 2023; 244:108388. [PMID: 36940792 DOI: 10.1016/j.pharmthera.2023.108388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/22/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023]
Abstract
Cardiac arrhythmias are a common and potentially serious cardiovascular disorders that affect both men and women. However, there is evidence to suggest that there may be sex-related differences in the prevalence, clinical presentation, and management of cardiac arrhythmias. Hormonal and cellular factors may play a role in these sex-specific differences. In addition, there are differences in the types of arrhythmias that men and women experience, with men more likely to experience ventricular arrhythmias and women more likely to experience supraventricular arrhythmias. The management of cardiac arrhythmias also differs between men and women. For example, some studies have found that women are less likely to receive appropriate treatment for arrhythmias and are more likely to have adverse outcomes following treatment. Despite these sex-related differences, the majority of research on cardiac arrhythmias has been conducted in men, and there is a need for more research to specifically examine the differences between men and women. This is especially important given that the prevalence of cardiac arrhythmia is increasing, and it is essential to understand how to effectively diagnose and treat these conditions in both men and women. In this review, we examine the current understanding of sex-related differences in cardiac arrhythmias. We also review the available data on sex-specific management strategies for cardiac arrhythmias and highlight areas of future research.
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Affiliation(s)
- Magda Haum
- Department of Medicine I, Munich University Hospital, Ludwig-Maximilian-University, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Germany
| | - Antonia Kellnar
- Department of Medicine I, Munich University Hospital, Ludwig-Maximilian-University, Munich, Germany
| | - Manuela Thienel
- Department of Medicine I, Munich University Hospital, Ludwig-Maximilian-University, Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Germany.
| | - Korbinian Lackermair
- Department of Medicine I, Munich University Hospital, Ludwig-Maximilian-University, Munich, Germany
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Higher Na+-Ca2+ Exchanger Function and Triggered Activity Contribute to Male Predisposition to Atrial Fibrillation. Int J Mol Sci 2022; 23:ijms231810724. [PMID: 36142639 PMCID: PMC9501955 DOI: 10.3390/ijms231810724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Male sex is one of the most important risk factors of atrial fibrillation (AF), with the incidence in men being almost double that in women. However, the reasons for this sex difference are unknown. Accordingly, in this study, we sought to determine whether there are sex differences in intracellular Ca2+ homeostasis in mouse atrial myocytes that might help explain male predisposition to AF. AF susceptibility was assessed in male (M) and female (F) mice (4–5 months old) using programmed electrical stimulation (EPS) protocols. Males were 50% more likely to develop AF. The Ca2+ transient amplitude was 28% higher in male atrial myocytes. Spontaneous systolic and diastolic Ca2+ releases, which are known sources of triggered activity, were significantly more frequent in males than females. The time to 90% decay of Ca2+ transient was faster in males. Males had 54% higher Na+-Ca2+ exchanger (NCX1) current density, and its expression was also more abundant. L-type Ca2+ current (ICaL) was recorded with and without BAPTA, a Ca2+ chelator. ICaL density was lower in males only in the absence of BAPTA, suggesting stronger Ca2+-dependent inactivation in males. CaV1.2 expression was similar between sexes. This study reports major sex differences in Ca2+ homeostasis in mouse atria, with larger Ca2+ transients and enhanced NCX1 function and expression in males resulting in more spontaneous Ca2+ releases. These sex differences may contribute to male susceptibility to AF by promoting triggered activity.
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Menichetti F, Nesti M, Notarstefano P, Fazi A, Del Rosso A, Solarino G, La Pira F, Giorgi D, Arena G, Rossi A, Segreti L, Piacenti M, Giovannini T, Santoro A, Casorelli E, Bongiorni MG, Giaccardi M. Prolonged care delivery time and reduced rate of electrophysiological procedures during the lockdown period due to Covid-19 outbreak. Expert Rev Med Devices 2021; 18:493-498. [PMID: 33970735 DOI: 10.1080/17434440.2021.1926985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVES The aim of this study is to demonstrate how Electrophysiology activity has been impacted by the pandemic Coronavirus disease 2019 (COVID-19). METHODS In this multicenter retrospective study, we analyze all consecutive patients admitted for electrophysiological procedures during the COVID-19 lockdown in the Tuscany region of Italy, comparing them to patients hospitalized in the corresponding period of the previous year. RESULTS The impact of COVID-19 on cardiac arrhythmia management was impressive, with a reduction of more than 50% in all kinds of procedures. A gender gap was observed, with a more relevant reduction for female patients. Arrhythmic urgencies requiring a device implant showed a reduced time from symptoms to first medical contact but the time from first medical contact to procedure was significantly prolonged. CONCLUSION Hospitals need to consider how outbreaks may affect health systems beyond the immediate infection. Routine activity should be based on a risk assessment between the prompt performance of procedure and its postponement. Retrospective observational analysis such as this study could be decisive in evidence-based medicine of any future pathogen outbreak.Nonstandard Abbreviations and Acronyms PM= pacemakerICD= implantable cardioverter defibrillatorECV= electrical cardioversionEPS= electrophysiological studyAP= ablations proceduresCIED= cardiac implantable electronic devicesWCD= wearable cardioverter defibrillatorEP Lab= Electrophysiology LaboratoriesAVNRT =atrioventricular nodal reentry tachycardiaAVRT= atrioventricular reentry tachycardiaAFL= atrial flutterAF= atrial fibrillationVT= ventricular tachycardiaAT= atrial tachycardia.
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Affiliation(s)
- Francesca Menichetti
- Electrophysiology Unit, Department of Internal Medicine, San Giuseppe Hospital, Italy
| | - Martina Nesti
- Cardiovascular and Neurological Department, San Donato Hospital, Arezzo, Italy
| | | | - Antonio Fazi
- Invasive Cardiology Unit, S. Maria Annunziata Hospital, Florence, Italy
| | - Attilio Del Rosso
- Electrophysiology Unit, Department of Internal Medicine, San Giuseppe Hospital, Italy
| | | | | | | | | | - Andrea Rossi
- Arrhythmology Unit, Department of Invasive Cardiology Fondazione "Gabriele Monasterio" CNR, Pisa, Italy
| | - Luca Segreti
- Second Division of Cardiology, Cardiac-Thoracic-Vascular Department, New Santa Chiara University Hospital, Pisa, Italy
| | - Marcello Piacenti
- Arrhythmology Unit, Department of Invasive Cardiology Fondazione "Gabriele Monasterio" CNR, Pisa, Italy
| | | | - Amato Santoro
- Department of Cardiology, University Hospital, Siena, Italy
| | - Ernesto Casorelli
- Department of Cardiology, Valdichiana Hospital, Montepulciano, Italy
| | - Maria Grazia Bongiorni
- Second Division of Cardiology, Cardiac-Thoracic-Vascular Department, New Santa Chiara University Hospital, Pisa, Italy
| | - Marzia Giaccardi
- Cardiology and Electrophysiology Unit, S. Maria Nuova Hospital, Florence, Italy
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Pereira PJS, Pugsley MK, Troncy E, Tan W, Pouliot M, Harper C, Prefontaine A, Easter A, Wallis R, Miraucourt L, Huang H, Accardi MV, Boulay E, Maghezzi MS, Authier S. Incidence of spontaneous arrhythmias in freely moving healthy untreated Sprague-Dawley rats. J Pharmacol Toxicol Methods 2019; 99:106589. [PMID: 31154034 DOI: 10.1016/j.vascn.2019.106589] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 05/07/2019] [Accepted: 05/25/2019] [Indexed: 12/18/2022]
Abstract
Spontaneous arrhythmia characterization in healthy rats can support interpretation when studying novel therapies. Male (n = 55) and female (n = 40) Sprague-Dawley rats with telemetry transmitters for a derivation II ECG. Arrhythmias were assessed from continuous ECG monitoring over a period of 24-48 h, and data analyzed using an automated detection algorithm with 100% manual over-read. While a total of 1825 spontaneous ventricular premature beats (VPB) were identified, only 7 rats (or 7.4%) did not present with any over the recording period. Spontaneous episode(s) of ventricular tachycardia (VT) were noted in males (27%) and females (3%). The incidence of VPB was significantly higher (p < 0.01) during the night time (7 pm-7 am) compared to daytime, while males presented with significantly (p < 0.001) more VPB than females. Most VPB were observed as single ectopic beats, followed by salvos (2 or 3 consecutive VPBs), and VT (i.e. 4 consecutive VPBs). Most VPBs were single premature ventricular contractions (PVCs) (57%), while the remaining were escape complexes (43%). Spontaneous premature junctional complexes (PJC) were also observed and were significantly more frequent during the night, and in males. Lastly, 596 episodes of spontaneous 2nd-degree atrioventricular (AV) block were identified and were significantly more frequent during the day time in males. Most 2nd-degree AV block episodes were Mobitz type I (57%), with a significantly (p < 0.05) higher incidence in males. This work emphasizes the importance of obtaining sufficient baseline data when undertaking arrhythmia analysis in safety study and provides a better understanding of both sex- and time- dependent effects of spontaneous arrhythmias in rats.
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Affiliation(s)
| | | | - Eric Troncy
- Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada
| | - Wendy Tan
- Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada
| | | | | | | | - Alison Easter
- Praxis Precision Medicines, Cambridge, MA, United States of America
| | - Rob Wallis
- Safety Pharmacology Consultant, London, United Kingdom
| | | | | | | | - Emmanuel Boulay
- Citoxlab, Laval, QC, Canada; Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada
| | | | - Simon Authier
- Citoxlab, Laval, QC, Canada; Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada.
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Yang HY, Firth JM, Francis AJ, Alvarez-Laviada A, MacLeod KT. Effect of ovariectomy on intracellular Ca 2+ regulation in guinea pig cardiomyocytes. Am J Physiol Heart Circ Physiol 2017; 313:H1031-H1043. [PMID: 28778911 DOI: 10.1152/ajpheart.00249.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/17/2017] [Accepted: 08/02/2017] [Indexed: 01/30/2023]
Abstract
This study addressed the hypothesis that long-term deficiency of ovarian hormones after ovariectomy (OVx) alters cellular Ca2+-handling mechanisms in the heart, resulting in the formation of a proarrhythmic substrate. It also tested whether estrogen supplementation to OVx animals reverses any alterations to cardiac Ca2+ handling and rescues proarrhythmic behavior. OVx or sham operations were performed on female guinea pigs using appropriate anesthetic and analgesic regimes. Pellets containing 17β-estradiol (1 mg, 60-day release) were placed subcutaneously in selected OVx animals (OVx + E). Cardiac myocytes were enzymatically isolated, and electrophysiological measurements were conducted with a switch-clamp system. In fluo-4-loaded cells, Ca2+ transients were 20% larger, and fractional sarcoplasmic reticulum (SR) Ca2+ release was 7% greater in the OVx group compared with the sham group. Peak L-type Ca2+ current was 16% larger in OVx myocytes with channel inactivation shifting to more positive membrane potentials, creating a larger "window" current. SR Ca2+ stores were 22% greater in the OVx group, and these cells showed a higher frequency of Ca2+ sparks and waves and shorter wave-free intervals. OVx myocytes showed higher frequencies of early afterdepolarizations, and a greater percentage of these cells showed delayed afterdepolarizations after exposure to isoprenaline compared with sham myocytes. The altered Ca2+ regulation occurring in the OVx group was not observed in the OVx + E group. These findings suggest that long-term deprivation of ovarian hormones in guinea pigs lead to changes in myocyte Ca2+-handling mechanisms that are considered proarrhythmogenic. 17β-Estradiol replacement prevented these adverse effects.NEW & NOTEWORTHY Ovariectomized guinea pig cardiomyocytes have higher frequencies of Ca2+ waves, and isoprenaline-challenged cells display more early afterdepolarizations, delayed afterdepolarizations, and extra beats compared with sham myocytes. These alterations to Ca2+ regulation were not observed in myocytes from ovariectomized guinea pigs supplemented with 17β-estradiol, suggesting that ovarian hormone deficiency modifies cardiac Ca2+ regulation, potentially creating proarrhythmic substrates.
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Affiliation(s)
- Hsiang-Yu Yang
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and.,Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defence Medical Center, Taipei, Taiwan
| | - Jahn M Firth
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Alice J Francis
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Anita Alvarez-Laviada
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
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Parks RJ, Bogachev O, Mackasey M, Ray G, Rose RA, Howlett SE. The impact of ovariectomy on cardiac excitation-contraction coupling is mediated through cAMP/PKA-dependent mechanisms. J Mol Cell Cardiol 2017; 111:51-60. [PMID: 28778766 DOI: 10.1016/j.yjmcc.2017.07.118] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/11/2017] [Accepted: 07/28/2017] [Indexed: 12/18/2022]
Abstract
Ovariectomy (OVX) promotes sarcoplasmic reticulum (SR) Ca2+ overload in ventricular myocytes. We hypothesized that the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway contributes to this Ca2+ dysregulation. Myocytes were isolated from adult female C57BL/6 mice following either OVX or sham surgery (surgery at ≈1mos). Contractions, Ca2+ concentrations (fura-2) and ionic currents were measured simultaneously (37°C, 2Hz) in voltage-clamped myocytes. Intracellular cAMP levels were determined with an enzyme immunoassay; phosphodiesterase (PDE) and adenylyl cyclase (AC) isoform expression was examined with qPCR. Ca2+ currents were similar in myocytes from sham and OVX mice but Ca2+ transients, excitation-contraction (EC)-coupling gain, SR content and contractions were larger in OVX than sham cells. To determine if the cAMP/PKA pathway mediated OVX-induced alterations in EC-coupling, cardiomyocytes were incubated with the PKA inhibitor H-89 (2μM), which abolished baseline differences. While basal intracellular cAMP did not differ, levels were higher in OVX than sham in the presence of a non-selective PDE inhibitor (300μM IBMX), or an AC activator (10μM forskolin). This suggests the production of cAMP by AC and its breakdown by PDE were enhanced by OVX. Consistent with this, mRNA levels for both AC5 and PDE4A were higher in OVX in comparison to sham. Differences in Ca2+ homeostasis and contractions were abolished when sham and OVX cells were dialyzed with patch pipettes containing the same concentration of 8-bromoadenosine-cAMP (50μM). Interestingly, selective inhibition of PDE4 increased Ca2+ current only in OVX cells. Together, these findings suggest that estrogen suppresses SR Ca2+ release and that this is regulated, at least in part, by the cAMP/PKA pathway. These changes in the cAMP/PKA pathway may promote Ca2+ dysregulation and cardiovascular disease when ovarian estrogen levels fall. These results advance our understanding of female-specific cardiomyocyte mechanisms that may affect responses to therapeutic interventions in older women.
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Affiliation(s)
- Randi J Parks
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Oleg Bogachev
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Martin Mackasey
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Gibanananda Ray
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Robert A Rose
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Susan E Howlett
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada; Department of Medicine (Geriatric Medicine), Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
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Tamargo J, Rosano G, Walther T, Duarte J, Niessner A, Kaski JC, Ceconi C, Drexel H, Kjeldsen K, Savarese G, Torp-Pedersen C, Atar D, Lewis BS, Agewall S. Gender differences in the effects of cardiovascular drugs. EUROPEAN HEART JOURNAL - CARDIOVASCULAR PHARMACOTHERAPY 2017; 3:163-182. [DOI: 10.1093/ehjcvp/pvw042] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Santangeli P, Di Biase L, Basile E, Al-Ahmad A, Natale A. Outcomes in Women Undergoing Electrophysiological Procedures. Arrhythm Electrophysiol Rev 2016; 2:41-4. [PMID: 26835039 DOI: 10.15420/aer.2013.2.1.41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The number of invasive electrophysiological procedures is steadily increasing in Western countries, as the age of the population increases and technologies advance. In recent years, gender-related differences in cardiac rhythm disorders have been increasingly appreciated, which can potentially have a great impact on the outcomes of invasive electrophysiological procedures. Among supraventricular arrhythmias, women have a higher incidence of atrioventricular nodal re-entrant tachycardia and a significantly lower incidence of atrioventricular re-entrant tachycardia compared with males, and present to ablation procedures later and after having failed more antiarrhythmic drugs. The results of catheter ablation of atrial fibrillation in women have been reported worse than in men. This finding is possibly due to a later referral of females to ablation procedures, who present older and with a higher incidence of long-standing persistent atrial fibrillation. With regard to cardiac device implantation procedures, a smaller survival benefit from prophylactic implantable cardioverter defibrillator (ICD) implantation has been shown in women, essentially due to gender-specific differences in the clinical course of patients with severe left ventricular dysfunction, with women dying predominantly from non-arrhythmic causes. On the other side, the clinical outcome of cardiac resynchronisation therapy seems to be more favourable in women, who experience a greater degree of reverse left ventricular remodelling and a striking decrease of heart failure events or mortality after biventricular pacing. This review will summarise the available evidence on gender-related differences in outcomes of invasive electrophysiological procedures.
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Affiliation(s)
- Pasquale Santangeli
- Division of Cardiology, Stanford University School of Medicine, California, US; Texas Cardiac Arrhythmia Institute, St. David's Medical Center, Texas, US; Department of Cardiology, University of Foggia, Foggia, Italy
| | - Luigi Di Biase
- Texas Cardiac Arrhythmia Institute, St. David's Medical Center, Texas, US; Department of Cardiology, University of Foggia, Foggia, Italy
| | - Eloisa Basile
- Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy
| | - Amin Al-Ahmad
- Division of Cardiology, Stanford University School of Medicine, California, US
| | - Andrea Natale
- Division of Cardiology, Stanford University School of Medicine, California, US; Texas Cardiac Arrhythmia Institute, St. David's Medical Center, Texas, US
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Mochalina N, Juhlin T, Öhlin B, Carlson J, Holmqvist F, Platonov PG. Predictors of successful cardioversion with vernakalant in patients with recent-onset atrial fibrillation. Ann Noninvasive Electrocardiol 2014; 20:140-7. [PMID: 25040826 DOI: 10.1111/anec.12178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Vernakalant is a novel atrial-selective antiarrhythmic drug able to convert recent-onset atrial fibrillation (AF) with reportedly low proarrhythmic risk. Successful cardioversion predictors are largely unknown. We sought to evaluate clinical and electrocardiographic predictors of cardioversion of recent-onset AF with vernakalant. METHODS Consecutive patients with AF ≤48 hours admitted for cardioversion with vernakalant (n = 113, median age 62 years, 69 male) were included. Sinus rhythm (SR) within 90 minutes after infusion start was considered to be successful cardioversion. Predictive values of demographics, concomitant therapy, comorbidities, and electrocardiographic parameters were assessed. Atrial fibrillatory rate (AFR), exponential decay, and mean fibrillatory wave amplitude were measured from surface ECG using QRST cancellation and time-frequency analysis. RESULTS Cardioversion was achieved in 66% of patients. Conversion rate was higher in women than in men (80% vs 58%, P = 0.02) while none of other clinical characteristics, including index AF episode duration, could predict SR restoration. Female gender was predictive of vernakalant's effect in logistic regression analysis (OR = 2.82 95%CI 1.18-6.76, P = 0.020). There was no difference in AFR (350 ± 60 vs 348 ± 62 fibrillations per minute [fpm], P = 0.893), mean fibrillatory wave amplitude (86 ± 33 vs 88 ± 67 μV, P = 0.852), or exponential decay (1.30 ± 0.42 vs 1.35 ± 0.42, P = 0.376) between responders and nonresponders. CONCLUSIONS Female gender is associated with a higher rate of SR restoration using intravenous (i.v.) vernakalant for recent-onset AF. ECG-derived indices of AF organization, which previous studies associated with effect of rhythm control interventions, did not predict vernakalant's effect.
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Affiliation(s)
- Natalia Mochalina
- Department of Emergency Medicine; Skåne University Hospital, Malmö, Sweden
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El Khoury N, Mathieu S, Marger L, Ross J, El Gebeily G, Ethier N, Fiset C. Upregulation of the hyperpolarization-activated current increases pacemaker activity of the sinoatrial node and heart rate during pregnancy in mice. Circulation 2013; 127:2009-20. [PMID: 23609807 DOI: 10.1161/circulationaha.113.001689] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Pregnancy is associated with a faster heart rate (HR), which is a risk factor for arrhythmias. However, the underlying mechanisms for this increased HR are poorly understood. Therefore, this study was performed to gain mechanistic insight into the pregnancy-induced increase in HR. METHODS AND RESULTS Using surface ECG we observed that pregnant (P) mice have faster HR (531±14 beats per minute [bpm]) compared with nonpregnant (NP) mice (470±27 bpm; P<0.03). Results obtained with Langendorff-perfused hearts showed that this difference persisted in the absence of autonomic nervous innervation (NP, 327±16 bpm; P, 385±18 bpm; P<0.02). Spontaneous action potentials of sinoatrial node cells from pregnant mice exhibited higher automaticity (NP, 292±13 bpm; P, 330±12 bpm; P=0.047) and steeper diastolic depolarization (NP, 0.20±0.03 V/s; P, 0.40±0.06 V/s; P=0.004). Pregnancy increased the density of the hyperpolarization-activated current (If) (at -90mV: NP, -15.2±1.0 pA/pF; P, -28.6±2.9 pA/pF; P=0.0002) in sinoatrial node cells. Voltage dependence of the If activation curve and the intracellular cAMP levels were unchanged in sinoatrial node cells of pregnant mice. However, there was a significant increase in HCN2 channel protein expression with no change in HCN4 expression. Maximal depolarizing shift of the If activation curve induced by isoproterenol was attenuated in pregnancy. This reduced response to isoproterenol may be attributable to the lower cAMP sensitivity of HCN2 isoform compared with that of HCN4. CONCLUSIONS This study shows that an increase in If current density contributes to the acceleration of sinoatrial node automaticity and explains, in part, the higher HR observed in pregnancy.
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Affiliation(s)
- Nabil El Khoury
- Research Center, Montreal Heart Institute, 5000 Bélanger, Montréal, Québec, Canada, H1T 1C8
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Ayalasomayajula S, Yeh CM, Vaidyanathan S, Flannery B, Dieterich HA, Howard D, Bedigian MP, Dole WP. Effects of Aliskiren, a Direct Renin Inhibitor, on Cardiac Repolarization and Conduction in Healthy Subjects. J Clin Pharmacol 2013; 48:799-811. [DOI: 10.1177/0091270008319330] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Lasseter KC, Aubets J, Chuecos F, Gil EG. Aclidinium Bromide, a Long-Acting Antimuscarinic, Does Not Affect QT Interval in Healthy Subjects. J Clin Pharmacol 2013; 51:923-32. [DOI: 10.1177/0091270010374471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sex differences in mechanisms of cardiac excitation-contraction coupling. Pflugers Arch 2013; 465:747-63. [PMID: 23417603 PMCID: PMC3651827 DOI: 10.1007/s00424-013-1233-0] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 01/29/2013] [Accepted: 01/30/2013] [Indexed: 11/25/2022]
Abstract
The incidence and expression of cardiovascular diseases differs between the sexes. This is not surprising, as cardiac physiology differs between men and women. Clinical and basic science investigations have shown important sex differences in cardiac structure and function. The pervasiveness of sex differences suggests that such differences must be fundamental, likely operating at a cellular level. Indeed, studies have shown that isolated ventricular myocytes from female animals have smaller and slower contractions and underlying calcium transients compared to males. Recent evidence suggests that this arises from sex differences in components of the cardiac excitation–contraction coupling pathway, the sequence of events linking myocyte depolarization to calcium release from the sarcoplasmic reticulum and subsequent contraction. The concept that sex hormones may regulate intracellular calcium at the level of the cardiomyocyte is important, as levels of these hormones decline in both men and women as the incidence of cardiovascular disease rises. This review focuses on the impact of sex on cardiac contraction, in particular at the cellular level, and highlights specific components of the excitation–contraction coupling pathway that differ between the sexes. Understanding sex hormone regulation of calcium homeostasis in the heart may reveal new avenues for therapeutic strategies to treat cardiac dysfunction and cardiovascular diseases.
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Drača S. Differences in cerebrogenic cardiac disturbance in men and women. Lancet Neurol 2012; 11:842; author reply 842-3. [DOI: 10.1016/s1474-4422(12)70211-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fares E, Parks RJ, MacDonald JK, Egar JM, Howlett SE. Ovariectomy enhances SR Ca2+ release and increases Ca2+ spark amplitudes in isolated ventricular myocytes. J Mol Cell Cardiol 2012; 52:32-42. [DOI: 10.1016/j.yjmcc.2011.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/18/2011] [Accepted: 09/02/2011] [Indexed: 11/24/2022]
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18
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Thomas N, Jasmin J, Lisanti M, Iacobas D. Sex differences in expression and subcellular localization of heart rhythm determinant proteins. Biochem Biophys Res Commun 2011; 406:117-22. [DOI: 10.1016/j.bbrc.2011.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 02/01/2011] [Indexed: 11/15/2022]
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Farkas AS, Nattel S. Minimizing Repolarization-Related Proarrhythmic Risk in Drug Development and Clinical Practice. Drugs 2010; 70:573-603. [DOI: 10.2165/11535230-000000000-00000] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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20
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Bouchaud O, Imbert P, Touze JE, Dodoo ANO, Danis M, Legros F. Fatal cardiotoxicity related to halofantrine: a review based on a worldwide safety data base. Malar J 2009; 8:289. [PMID: 20003315 PMCID: PMC2801676 DOI: 10.1186/1475-2875-8-289] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 12/10/2009] [Indexed: 11/23/2022] Open
Abstract
Background Halofantrine (HF) was considered an effective and safe treatment for multi-drug resistant falciparum malaria until 1993, when the first case of drug-associated death was reported. Since then, numerous studies have confirmed cardiac arrythmias, possibly fatal, in both adults and children. The aim of the study was to review fatal HF related cardiotoxicity. Methods In addition, to a systematic review of the literature, the authors have had access to the global safety database on possible HF related cardiotoxicity provided by GlaxoSmithKline. Results Thirty-five cases of fatal cardiotoxicity related to HF, including five children, were identified. Females (70%) and patients from developing countries (71%) were over-represented in this series. Seventy-four percent of the fatal events occurred within 24 hours of initial exposure to HF. Twenty six patients (74%) had at least one predisposing factor for severe cardiotoxicity, e.g., underlying cardiac disease, higher than recommended doses, or presence of a concomitant QT-lengthening drug. All (100%) of the paediatric cases had either a contraindication to HF or an improper dose was given. In six cases there was no malaria. Conclusion A distinction should be made between common but asymptomatic QT-interval prolongation and the much less common ventricular arrhythmias, such as torsades de pointes, which can be fatal and seem to occur in a very limited number of patients. The majority of reported cardiac events occurred either in patients with predisposing factors or with an improper dose. Therefore, in the rare situations in which HF is the only therapeutic option, it can still be given after carefully checking for contraindications, such as underlying cardiac disease, bradycardia, metabolic disorders, personal or family history of long QT-interval or concomitant use of another QT-prolonging drug (e.g., mefloquine), especially in females.
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Affiliation(s)
- Olivier Bouchaud
- Service des maladies infectieuses et tropicales, Hôpital Avicenne AP-HP et Université Paris 13, 125 rue de Stalingrad, 93009 Bobigny, France.
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Iacobas DA, Iacobas S, Thomas N, Spray DC. Sex-dependent gene regulatory networks of the heart rhythm. Funct Integr Genomics 2009; 10:73-86. [PMID: 19756788 DOI: 10.1007/s10142-009-0137-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 08/19/2009] [Accepted: 08/22/2009] [Indexed: 01/27/2023]
Abstract
Expression level, control, and intercoordination of 66 selected heart rhythm determinant (HRD) genes were compared in atria and ventricles of four male and four female adult mice. We found that genes encoding various adrenergic receptors, ankyrins, ion channels and transporters, connexins, cadherins, plakophilins, and other components of the intercalated discs form a complex network that is chamber dependent and differs between the two sexes. In addition, most HRD genes in atria had higher expression in males than in females, while in ventricles, expression levels were mostly higher in females than in males. Moreover, significant chamber differences were observed between the sexes, with higher expression in atria than ventricles for males and higher expression in ventricles than atria for females. We have ranked the selected genes according to their prominence (new concept) within the HRD gene web defined as extent of expression coordination with the other web genes and stability of expression. Interestingly, the prominence hierarchy was substantially different between the two sexes. Taken together, these findings indicate that the organizational principles of the heart rhythm transcriptome are sex dependent, with the newly introduced prominence analysis allowing identification of genes that are pivotal for the sexual dichotomy.
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Affiliation(s)
- D A Iacobas
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Kennedy Center, New York, NY 10461, USA.
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22
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Shimoni Y, Emmett T, Schmidt R, Nygren A, Kargacin G. Sex-dependent impairment of cardiac action potential conduction in type 1 diabetic rats. Am J Physiol Heart Circ Physiol 2009; 296:H1442-50. [DOI: 10.1152/ajpheart.01150.2008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The incidence of diabetes mellitus is increasing. Cardiac dysfunction often develops, resulting in diverse arrhythmias. These arise from ion channel remodeling or from altered speed and pattern of impulse propagation. Few studies have investigated impulse propagation in the diabetic heart. We previously showed a reduced conduction reserve in the diabetic heart, with associated changes in intercellular gap junctions. The present study investigated whether these effects are sex specific. Hearts from control and streptozotocin-diabetic male and female rats were used. Optical mapping was performed with the voltage-sensitive dye di-4-ANEPPS, using Langendorff-perfused hearts. Isolated ventricular cells and tissue sections were used for immunofluorescent labeling of the gap junction protein connexin43 (Cx43). The gap junction uncoupler heptanol (0.75 mM) or elevated K+ (9 mM, to reduce cell excitability) produced significantly greater slowing of propagation in diabetic males than females. In ovariectomized diabetic females, 9 mM K+ slowed conduction significantly more than in nonovariectomized females. The subcellular redistribution (lateralization) of the gap junction protein Cx43 was smaller in diabetic females. Pretreatment of diabetic males with the angiotensin-converting enzyme inhibitor quinapril reduced Cx43 lateralization and the effects of 9 mM K+ on propagation. In conclusion, the slowing of cardiac impulse propagation in type 1 diabetes is smaller in female rats, partly due to the presence of female sex hormones. This difference is (partly) mediated by sex differences in activation of the cardiac renin-angiotensin system.
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23
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Deneke T, Müller P, Lawo T, Lemke B, Horlitz M, Calcum B, Bösche LI, Mügge A, Grewe PH. Gender differences in onset of symptoms in AV nodal re-entrant and accessory pathway-mediated re-entrant tachycardia. Herzschrittmacherther Elektrophysiol 2009; 20:33-38. [PMID: 19421838 DOI: 10.1007/s00399-009-0036-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 01/08/2009] [Indexed: 05/27/2023]
Abstract
PURPOSE Is onset of symptoms in AV nodal re-entrant tachycardia (AVNRT) and accessory pathway-mediated re-entrant tachycardia (AVRT) patients gender-specific? METHODS Intra- and inter-gender differences in onset of symptoms and mechanism of supraventricular tachycardia in adult patients undergoing catheter ablation for AVNRT or AVRT (N=230) were documented. RESULTS Women with AVNRT were significantly younger at onset of symptoms compared to men (38+/-18, 51+/-18 years, p=0.01). Male AVNRT patients were significantly older at onset of symptoms compared to male AVRT patients (51+/-18, 25+/-11 years, p=0.04) but there was no difference in women. Symptoms beginning <30 years in men predicted AVRT in 73%, and beginning >or=30 years the predominant mechanism was AVNRT (85%). In women AVNRT was the most likely mechanism independent of symptom onset (>75%). CONCLUSIONS Symptoms beginning in patients with AVNRT and AVRT prior to age 30 correlates with a 70% incidence of AVRT in men and a 80% incidence of AVNRT in women. Onset of palpitations >or= age 30 relates to AVNRT in 85% of patients.
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Affiliation(s)
- T Deneke
- BG University Hospital Bergmannsheil, University Heart Center Bochum, Bürkle-de-la-Camp-Platz 2, 44789, Bochum, Deutschland.
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24
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Abstract
This perspective considers progress in understanding how genetic influences modulate susceptibility to lethal ventricular arrhythmias in cardiac patients and the population at large, as opposed to those with rare inherited arrhythmic conditions, such as the Long-QT and Brugada syndromes. It addresses largely unresolved issues, such as how important these effects may be and what we know of underlying mediators and pathways. Attention is given to newly revealed mechanisms of genomic function and the problem of identifying new susceptibility genes and targets useful in developing improved strategies for sudden death prevention.
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Affiliation(s)
- Peter M Spooner
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
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25
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Cottrell DB, Jones MM. Women with dysrhythmia: a clinical challenge. Crit Care Nurs Clin North Am 2008; 20:311-4. [PMID: 18644514 DOI: 10.1016/j.ccell.2008.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There are identified differences in the electrophysiology structure and measurements in women and men. An understanding of these differences and of the increased incidence and prevalence of dysrhythmias in women, the differences in presentation, and the differences in risk factors for these dysrhythmias will help guide treatment decisions. As new knowledge is gained through research, practitioners can provide gender-specific care to women who have or are at increased risk of cardiac dysrhythmia.
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Affiliation(s)
- Damon B Cottrell
- Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
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26
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Zopf Y, Rabe C, Neubert A, Gassmann KG, Rascher W, Hahn EG, Brune K, Dormann H. Women encounter ADRs more often than do men. Eur J Clin Pharmacol 2008; 64:999-1004. [PMID: 18604529 DOI: 10.1007/s00228-008-0494-6] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Accepted: 04/02/2008] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several publications indicate that the female gender experiences a higher incidence of adverse drug reactions (ADRs) than does the male gender. The reasons, however, remain unclear. Gender-specific differences in the pharmacokinetic and pharmacodynamic behaviour of drugs could not be identified as an explanation. The aim of this study was to analyse ADR risk with respect to gender, age and number of prescribed drugs. METHODS A prospective multicenter study based on intensive pharmacovigilance was conducted. Information on patient characteristics and evaluated ADRs was stored in a pharmacovigilance database--KLASSE. RESULTS In 2,371 patients (1,012 female subjects), 25,532 drugs were prescribed. In 782 patients, at least one ADR was found. A multivariate regression analysis adjusting for age, body mass index (BMI) and number of prescribed drugs showed a significant influence of female gender on the risk of encountering ADRs [odds ratio (OR) 1.596, confidence interval (CI) 1.31-1.94; p < 0.0001). Dose-related ADRs (51.8%) were the dominant type in female subjects. Comparing system organ classes of the World Health Organisation (SOC-WHO), cardiovascular (CV) ADRs were particularly frequent in female subjects (OR 1.92, CI 1.15-3.19; p = 0.012). CONCLUSION Our data confirm the higher risk of ADRs among female subjects compared with a male cohort. Several explanations were investigated. No single risk factor could be identified.
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Affiliation(s)
- Y Zopf
- Department of Medicine 1, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
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27
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Pedersen HS, Elming H, Seibaek M, Burchardt H, Brendorp B, Torp-Pedersen C, Køber L. Risk factors and predictors of Torsade de pointes ventricular tachycardia in patients with left ventricular systolic dysfunction receiving Dofetilide. Am J Cardiol 2007; 100:876-80. [PMID: 17719337 DOI: 10.1016/j.amjcard.2007.04.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 04/13/2007] [Accepted: 04/13/2007] [Indexed: 10/23/2022]
Abstract
The purpose of this study was to identify risk factors of Torsade de pointes (TdP) ventricular tachycardia in patients medicated with a class III antiarrhythmic drug (dofetilide) and left ventricular systolic dysfunction with heart failure (HF) or recent myocardial infarction (MI). The 2 Danish Investigations of Arrhythmia and Mortality on Dofetilide (DIAMOND) studies enrolled patients with HF (DIAMOND-HF) or MI (DIAMOND-MI) and left ventricular systolic dysfunction. The present analysis includes only patients treated solely with dofetilide. The incidence of TdP was 2.1% (32 of 1,511). Twenty-five of the incidences occurred in the DIAMOND-HF study and 7 cases in the DIAMOND-MI study (p = 0.0015). TdP was more frequent in women than in men (47% vs 28%, p = 0.02). Risk factors for developing TdP were female gender (odds ratio 2.2, 95% confidence interval [CI] 1.0 to 5.0), MI within 8 weeks (odds ratio 0.3, 95% CI 0.1 to 0.7), being in New York Heart Association class III or IV (odds ratio 3.2, 95% CI 1.2 to 8.6), and baseline QTc duration (odds ratio 1.14, 95% CI 1.00 to 1.30) per 10 ms. Women with chronic HF, QTc duration >400 ms. and New York Heart Association class III or IV had a risk of TdP of 10%, whereas no TdP episodes were observed in patients with QTc duration <400 ms. In conclusion, severity of HF, female gender, and QTc duration make it possible to identify patients with a high risk of early TdP when treated with dofetilide. Patients with recent MI less often had TdP compared with patients with chronic HF.
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Affiliation(s)
- Henriette Sloth Pedersen
- Department of Cardiology and Endocrinology, University Hospital of Copenhagen, Frederiksberg Hospital, Frederiksberg, Denmark.
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Holmqvist F, Stridh M, Waktare JEP, Roijer A, Sörnmo L, Platonov PG, Meurling CJ. Atrial fibrillation signal organization predicts sinus rhythm maintenance in patients undergoing cardioversion of atrial fibrillation. ACTA ACUST UNITED AC 2006; 8:559-65. [PMID: 16831838 DOI: 10.1093/europace/eul072] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS Electrical remodelling is believed to influence the outcome following cardioversion of patients with persistent atrial fibrillation (AF). However, the results in clinical studies are conflicting. We assessed the hypothesis that non-invasively obtained atrial fibrillatory organization can be used as a predictor of sinus rhythm (SR) maintenance. METHODS AND RESULTS Fifty-four patients (37 men, age 67+/-11) with persistent AF (median duration 3 months, 1 day to 18 months), without anti-arrhythmic drug treatment, referred for cardioversion were studied. Assessment of the atrial harmonic decay was made by time-frequency analysis of the ECG. At 1-month follow-up, 30 patients had relapsed into AF. The mean harmonic decay at inclusion of those relapsing into AF was 1.5+/-0.3 compared with 1.1+/-0.3 among those maintaining SR (P=0.0004). Using a cut-off value of harmonic decay <or=1.5 to determine suitability for cardioversion would have resulted in a clinically useful discriminator (sensitivity=92%, specificity=47%, PPV=59%, and NPV=88%). CONCLUSION This study shows that patients relapsing rapidly to AF have a higher harmonic decay than those maintaining SR. The degree of AF signal organization (harmonic decay) was a superior discriminator to other patient parameters. Further studies are needed to confirm these results and to determine the electrophysiological correlate of harmonic decay.
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Affiliation(s)
- Fredrik Holmqvist
- Department of Cardiology, Lund University Hospital, SE-221 85 Lund, Sweden.
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29
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Wild R. Understanding the effects of SERMs on cardiovascular disease. Am J Obstet Gynecol 2006; 194:1211-2. [PMID: 16647901 DOI: 10.1016/j.ajog.2005.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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30
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Scholten MF, Thornton AS, Mekel JM, Jordaens LJ. Targets and endpoints in ablation therapy for atrial fibrillation in the light of pathophysiological mechanisms. J Interv Card Electrophysiol 2006; 15:27-33. [PMID: 16680547 DOI: 10.1007/s10840-006-6334-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Accepted: 11/22/2005] [Indexed: 11/24/2022]
Abstract
Atrial fibrillation (AF), an important public health problem is a complex and multifactorial arrhythmia. Non-pharmacological treatment for symptomatic patients is of increasing importance. The different catheter ablation techniques in AF treatment developed during recent years, all based on different pathophysiological insights, are discussed. The non-standardized use of different follow-up methods after ablation make interpretation and comparison of results difficult.
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Affiliation(s)
- Marcoen F Scholten
- Clinical Electrophysiology Unit, Department of Cardiology, Thoraxcentre, Erasmus MC, Dr Molewaterplein 40., 3015 GD, Rotterdam, The Netherlands.
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31
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Camm AJ. Clinical trial design to evaluate the effects of drugs on cardiac repolarization: Current state of the art. Heart Rhythm 2005; 2:S23-9. [PMID: 16253928 DOI: 10.1016/j.hrthm.2004.09.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Indexed: 01/10/2023]
Abstract
Prolongation of the QT interval associated with the potentially fatal arrhythmia known as torsades de pointes has been a common cause of the withdrawal of several promising drugs from the market. Many antihistamines, antibiotics, antimalarials, antidepressants, neuroleptics, antipsychotics, and imidazole antifungal agents have been shown to produce torsades, and all by the same mechanism. Advances in basic science and preclinical testing have begun to provide a scientific basis for distinguishing arrhythmogenicity from drug-induced QT effects. Many new techniques have been developed, and many others currently are being developed to facilitate the design of clinical trials to evaluate the effects of drugs on cardiac repolarization. The improvements in clinical trial design may help identify drugs that could induce torsades, halting futile research, potentially saving lives, and saving hundreds of millions of dollars in drug development. In the absence of any completely reliable surrogate measure for the arrhythmogenic potential of a drug, regulators have determined that QT interval prolongation should be intensively investigated in every drug that is developed. This article presents the basic mechanics of QT interval assessment and describes new developments that may make this measure a more accurate predictor of the effects of drugs on cardiac repolarization. It is absolutely essential that trial designs incorporate many ECG recordings, consistent QT interval measurement, and appropriate control or correction of the QT interval for heart rate in order to provide reproducible, scientifically meaningful results.
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Affiliation(s)
- A John Camm
- St. George's Hospital Medical School, University of London, Cranmer Terrace, London SW17 0RE, UK.
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32
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Abstract
Drug therapy may induce Q-T prolongation by alteration of potassium ion currents in cardiac cells, resulting in abnormal repolarization. Q-T prolongation, whether congenital or acquired, has been associated with the development of the malignant dysrhythmia Torsade de Pointes (TdP), which may result in sudden death. Re-cent regulatory actions and drug withdrawals due to Q-T prolongation or TdP have focused attention on this issue. Although our understanding of the pathophysiology continues to evolve, both patient and medication factors contribute to the individual risk of drug-induced Q-T prolongation or TdP. The clinician should be aware of these issues when prescribing new drugs and should weigh the risks and benefits carefully when prescribing drugs known to prolong the Q-T interval.
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Affiliation(s)
- Louise W Kao
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN 46206, USA.
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Sica DA, Wood M, Hess M. Gender and its effect in cardiovascular pharmacotherapeutics: recent considerations. ACTA ACUST UNITED AC 2005; 11:163-6. [PMID: 15947543 DOI: 10.1111/j.1527-5299.2005.04171.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gender differences in drug pharmacokinetics and pharmacodynamics have been recognized for some time. This issue has generally been ignored in clinical practice, despite there being ample evidence to suggest that gender can influence multiple aspects of pharmacokinetics. Gastric acid secretion, gastrointestinal blood flow, proportions of muscular and adipose tissue, the amount of drug-binding proteins, gender-specific changes in the available amount of P450 isozymes, physiologic and hormonal changes during the menstrual cycle, and differences in renal blood flow are several factors that may have some bearing on sex-related differences in pharmacokinetics. Furthermore, female-specific issues such as pregnancy, menopause, oral contraceptive use, and menstruation may independently influence drug metabolism and serve as confounders to the interpretation of gender differences in drug handling or effect. While gender-related pharmacodynamic data are limited, evidence suggests that women are more prone to the development of torsade de pointes from proarrhythmic drugs such as quinidine or d-sotalol and have an increased cardiovascular risk with the use of digoxin. The specific risk:benefit ratio for individual cardiovascular medications should be more routinely considered in the context of gender.
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Affiliation(s)
- Domenic A Sica
- Departments of Medicine and Pharmacology, Section of Clinical Pharmacology and Hypertension, Division of Nephrology; Virginia Commonwealth University Health System, Richmond, VA 23298, USA.
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Teplitz L, Igić R, Berbaum ML, Schwertz DW. Sex Differences in Susceptibility to Epinephrine-Induced Arrhythmias. J Cardiovasc Pharmacol 2005; 46:548-55. [PMID: 16160611 DOI: 10.1097/01.fjc.0000179435.26373.81] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Gender differences in incidence of cardiac arrhythmias have been documented. It is generally believed that cardiac pathology provides an arrhythmogenic substrate but that a trigger such as sympathetic nervous system activation is required to initiate arrhythmias. This study was done to determine whether there is a sex difference in susceptibility to epinephrine-induced arrhythmias in healthy rats without preexisting pathology and to determine whether gonadal hormones play a role in development of arrhythmias. Untreated, sham-operated, and gonadectomized male and female rats were anesthetized and given IV boluses of epinephrine. ECG, heart rate, and blood pressure were measured continuously for 1 minute and intermittently over a period of 30 minutes. Male rat hearts have a higher occurrence and frequency of epinephrine-induced premature ventricular contractions, missed beats, and blocks than female rat hearts. Ovariectomy increases arrhythmias, thereby abolishing the female advantage. Castration has no effect on occurrence and frequency of premature ventricular contractions but attenuates missed beats and blocks. Sex differences and effect of gonadectomy on epinephrine-induced alterations in heart rate and blood pressure implicate baroreceptor reflex in the dimorphic arrhythmogenic response. Male rat hearts are more susceptible than female hearts to epinephrine-induced arrhythmias, and gonadal hormones play a role in this disparity.
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Affiliation(s)
- Linda Teplitz
- Department of Medical Surgical Nursing, University of Illinois at Chicago, and Department of Anesthesiology and Pain Management, John H. Stroger, Jr. Hospital of Cook County, Chicago, Illinois 60612, USA
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