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1.
J Cardiovasc Pharmacol ; 82(3): 212-220, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37410999

RESUMO

ABSTRACT: Remdesivir, approved for the treatment of COVID-19, has been associated with heart-rate corrected QT interval (QTc) prolongation and torsade de pointes in case reports. However, data are conflicting regarding the ability of remdesivir to inhibit the human ether-a-go-go-related gene (hERG) -related current. The objective of this study was to investigate the effects remdesivir and its primary metabolite, GS-441524, on hERG-related currents. Human embryonic kidney 293 cells stably expressing hERG were treated with various concentrations of remdesivir and GS-441524. The effects of acute and prolonged exposure on hERG-related current were assessed using whole-cell configuration of voltage-clamp protocols. Acute exposure to remdesivir and GS-441524 had no effect on hERG currents and the half-activation voltage (V 1/2 ). Prolonged treatment with 100 nM and 1 µM remdesivir significantly reduced peak tail currents and hERG current density. The propensity for remdesivir to prolong QTc intervals and induce torsade de pointes in predisposed patients warrants further investigation.


Assuntos
COVID-19 , Torsades de Pointes , Humanos , Canais de Potássio Éter-A-Go-Go/genética , Potássio , Tratamento Farmacológico da COVID-19 , Éteres , Bloqueadores dos Canais de Potássio/farmacologia
2.
Womens Health (Lond) ; 18: 17455057221112267, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35833667

RESUMO

OBJECTIVE: Palpitations during peri- and post-menopause are common. It is unclear what variables are related to palpitations in peri- and post-menopausal women. The purpose of this scoping review was to summarize potential correlates of palpitations in women transitioning through menopause. METHODS: The review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Authors included English-language, full-length, peer-reviewed, cross-sectional research articles on palpitations in menopausal women published through December 18, 2021, from PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and PsycINFO searches. Following de-duplication, screening of titles and abstracts, and review of full-texts, independent reviewers extracted data on variables studied in relationship to palpitations from 84 articles and resolved discrepancies. Authors extracted data on (1) demographic, clinical, biomarker, and symptom/quality of life variables and (2) data analysis method (bivariate, multivariate). Authors classified each variable as a likely, unlikely, or unclear correlate of palpitations. RESULTS: Articles were diverse in region of origin, sample sizes, and variables assessed in relationship to palpitations. Evidence for any one variable was sparse. Likely correlates of palpitations included race/ethnicity, lower physical activity, worse vasomotor symptoms (VMSs), worse sleep, and worse quality of life. Unlikely correlates included age, employment, education, marital status, socioeconomic status, comorbidities, body mass index, and sexual difficulties. Unclear correlates due to equivocal evidence were menopausal status, smoking, and depression. Unclear correlates due to insufficient evidence (less than three articles) included all of the assessed biomarkers, anxiety, and stress. CONCLUSION: Likely correlates were identified including race/ethnicity, physical activity, VMS, sleep, and quality of life. However, additional research is needed to better understand potential correlates of palpitations.


Assuntos
Menopausa , Qualidade de Vida , Estudos Transversais , Exercício Físico , Feminino , Humanos , Pós-Menopausa
3.
Front Cardiovasc Med ; 9: 894623, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36588548

RESUMO

Introduction: Drug-induced prolongation of the heart rate-corrected QT interval (QTc) is associated with increased risk for the potentially fatal arrhythmia torsades de pointes. Due to arrhythmia risk, clinical trials with cancer therapeutics often exclude patients based on thresholds for QTc prolongation. Our objective was to assess associations between prescriptions for QT-prolonging drugs and the odds of meeting cancer trial exclusionary QTc thresholds in a cohort of adults with advanced cancer. Methods: Electronic health records were retrospectively reviewed for 271 patients seen at our institutional molecular solid tumor clinic. Collected data included demographics, QTc measurements, ventricular arrhythmia-related diagnoses, and all inpatient and outpatient prescriptions. Potential associations were assessed between demographic and clinical variables, including prescriptions for QT-prolonging drugs, and QTc measurements. Results: Women had longer median QTc measurements than men (p = 0.030) and were prescribed more QT-prolonging drugs during the study (p = 0.010). In all patients, prescriptions for QT-prolonging drugs were associated with longer median and maximum QTc measurements at multiple assessed time points (i.e., for QT-prolonging drugs prescribed within 10, 30, 60, and 90 days of QTc measurements). Similarly, the number of QT-prolonging drugs prescribed was correlated with longer median and maximum QTc measurements at multiple time points. Common QTc-related exclusionary criteria were collected from a review of ClinicalTrials.gov for recent cancer clinical trials. Based on common exclusion criteria, prescriptions for QT-prolonging drugs increased the odds of trial exclusion. Conclusion: This study demonstrates that prescriptions for QT-prolonging drugs were associated with longer QTc measurements and increased odds of being excluded from cancer clinical trials.

4.
Clin Pharmacol Ther ; 109(6): 1499-1504, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33020898

RESUMO

We have previously reported that transdermal testosterone attenuates drug-induced QT interval lengthening in older men. However, it is unknown whether this is due to modulation of early ventricular repolarization, late repolarization, or both. In a secondary analysis of a prospective, randomized, double-blind, placebo-controlled three-way crossover study, we determined if transdermal testosterone and oral progesterone attenuate drug-induced lengthening of early and late ventricular repolarization, represented by the electrocardiographic measurements J-Tpeak c and Tpeak -Tend , respectively, as well as Tpeak -Tend /QT, a measure of transmural dispersion of repolarization. Male volunteers ≥ 65 years of age (n = 14) were randomized to receive transdermal testosterone 100 mg, oral progesterone 400 mg, or matching transdermal/oral placebo daily for 7 days. On the morning following the seventh day, subjects received intravenous ibutilide 0.003 mg/kg, after which electrocardiograms were performed serially. One subject was excluded due to difficulty in T-wave interpretation. Pre-ibutilide J-Tpeak c was lower during the testosterone phase than during progesterone and placebo (216 ± 23 vs. 227 ± 28 vs. 227 ± 21 ms, P = 0.002). Maximum post-ibutilide J-Tpeak c was also lower during the testosterone phase (233 ± 22 vs. 246 ± 29 vs. 248 ± 23 ms, P < 0.0001). Pre-ibutilide Tpeak -Tend was not significantly different during the three phases, but maximum post-ibutilide Tpeak -Tend was lower during the testosterone phase (80 ± 12 vs. 89 ± 18 vs. 86 ± 15 ms, P = 0.002). Maximum Tpeak -Tend /QT was also lower during the testosterone phase (0.199 ± 0.023 vs. 0.216 ± 0.035 vs. 0.209 ± 0.031, P = 0.005). Progesterone exerted minimal effect on drug-induced lengthening of J-Tpeak c, and no effect on Tpeak -Tend or Tpeak -Tend /QT. Transdermal testosterone attenuates drug-induced lengthening of both early and late ventricular repolarization in older men.


Assuntos
Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/tratamento farmacológico , Testosterona/administração & dosagem , Testosterona/uso terapêutico , Administração Cutânea , Administração Oral , Idoso , Idoso de 80 Anos ou mais , Antiarrítmicos/administração & dosagem , Antiarrítmicos/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Eletrocardiografia/efeitos dos fármacos , Humanos , Masculino , Progesterona/administração & dosagem , Progesterona/uso terapêutico , Estudos Prospectivos , Sulfonamidas/administração & dosagem , Sulfonamidas/farmacologia
5.
Circulation ; 142(15): e214-e233, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32929996

RESUMO

Many widely used medications may cause or exacerbate a variety of arrhythmias. Numerous antiarrhythmic agents, antimicrobial drugs, psychotropic medications, and methadone, as well as a growing list of drugs from other therapeutic classes (neurological drugs, anticancer agents, and many others), can prolong the QT interval and provoke torsades de pointes. Perhaps less familiar to clinicians is the fact that drugs can also trigger other arrhythmias, including bradyarrhythmias, atrial fibrillation/atrial flutter, atrial tachycardia, atrioventricular nodal reentrant tachycardia, monomorphic ventricular tachycardia, and Brugada syndrome. Some drug-induced arrhythmias (bradyarrhythmias, atrial tachycardia, atrioventricular node reentrant tachycardia) are significant predominantly because of their symptoms; others (monomorphic ventricular tachycardia, Brugada syndrome, torsades de pointes) may result in serious consequences, including sudden cardiac death. Mechanisms of arrhythmias are well known for some medications but, in other instances, remain poorly understood. For some drug-induced arrhythmias, particularly torsades de pointes, risk factors are well defined. Modification of risk factors, when possible, is important for prevention and risk reduction. In patients with nonmodifiable risk factors who require a potentially arrhythmia-inducing drug, enhanced electrocardiographic and other monitoring strategies may be beneficial for early detection and treatment. Management of drug-induced arrhythmias includes discontinuation of the offending medication and following treatment guidelines for the specific arrhythmia. In overdose situations, targeted detoxification strategies may be needed. Awareness of drugs that may cause arrhythmias and knowledge of distinct arrhythmias that may be drug-induced are essential for clinicians. Consideration of the possibility that a patient's arrythmia could be drug-induced is important.


Assuntos
American Heart Association , Arritmias Cardíacas , Eletrocardiografia , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/terapia , Fatores de Risco , Estados Unidos/epidemiologia
6.
J Interv Card Electrophysiol ; 57(1): 5-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31828560

RESUMO

Premature ventricular complexes (PVCs) are common arrhythmias in the clinical setting. PVCs in the structurally normal heart are usually benign, but in the presence of structural heart disease (SHD), they may indicate increased risk of sudden death. High PVC burden may induce cardiomyopathy and left ventricular (LV) dysfunction or worsen underlying cardiomyopathy. Sometimes PVCs may be a marker of underlying pathophysiologic process such as myocarditis. Identification of PVC burden is important, since cardiomyopathy and LV dysfunction can reverse after catheter ablation or pharmacological suppression. This state-of-the-art review discusses pathophysiology, clinical manifestations, how to differentiate benign and malignant PVCs, PVCs in the structurally normal heart, underlying SHD, diagnostic procedures (physical examination, electrocardiogram, ambulatory monitoring, exercise testing, echocardiography, cardiac magnetic resonance imaging, coronary angiography, electrophysiology study), and treatment (lifestyle modification, electrolyte imbalance, medical, and catheter ablation).


Assuntos
Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/terapia , Diagnóstico Diferencial , Humanos , Complexos Ventriculares Prematuros/fisiopatologia
7.
J Clin Pharmacol ; 60(5): 648-659, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31829451

RESUMO

A decrease in the human ether-a-go-go-related gene (hERG/KCNH2)-related channel has been linked to intrauterine fetal death. The formation of cytochrome P450 (CYP) 3A-mediated progesterone metabolites, 6-beta-hydroxy-progesterone (6ß-OHP) and 16α-hydroxy-progesterone (16α-OHP), is variable among adults and differs from fetal metabolism. The primary objective of this study was to assess the potential for progesterone metabolites to inhibit hERG-related current and predict QTc intervals. Whole-cell voltage-clamp electrophysiology was performed on human embryonic kidney 293 cells stably expressing hERG exposed to progesterone or metabolites. Both 6ß-OHP and 16α-OHP positively shifted the voltage dependence of activation relative to vehicle from -4.0 ± 0.8 to -0.3 ± 0.8 mV, P < .01; and 1.0 ± 0.6 mV, P < .01, respectively. In addition, 6ß-OHP decreased maximal outward tail currents from 49.4 ± 4.9 to 32.5 ± 4.1 pA/pF, P < 0.01, and reduced the expression of fully glycosylated hERG by 42%. Healthy female subjects were administered progesterone 400 mg orally for 7 days, ibutilide 0.003 mg/kg was infused, and serial electrocardiograms and blood samples collected. Relationships between rate-corrected QT intervals (QTcI) with circulating hormones and metabolites were assessed. The 6ß-OHP and 16α-OHP metabolites were independent predictors of QTcI intervals prior to and following ibutilide administration. In conclusion, the progesterone metabolites formed via CYP3A cause inhibitory effects on hERG channels and predict QTcI intervals in healthy women pretreated with progesterone. Further study into maternal and fetal exposure to these metabolites and potential to prolong cardiac repolarization is warranted.

9.
J Cardiovasc Electrophysiol ; 30(6): 941-949, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31006943

RESUMO

INTRODUCTION: Higher progesterone concentrations are protective against drug-induced prolongation of ventricular repolarization. We tested the hypothesis that pretreatment with progesterone reduces the incidence of drug-induced torsades de pointes (TdP). METHODS AND RESULTS: Female New Zealand white rabbits (2.5-3.2 kg) underwent ovariectomy and were randomized to undergo implantation with subcutaneous 21-day sustained release pellets containing progesterone 50 mg (n = 22) or placebo (n = 23). After 20 days, hearts were excised, mounted, and perfused with modified Krebs-Henseleit solution. The atrioventricular (AV) node was destroyed manually. Following a 15-minute equilibration period, hearts were perfused with dofetilide 100 nM for 30 minutes, during which the electrocardiogram was recorded continuously. Incidences of spontaneous TdP, other ventricular arrhythmias and mean QTc intervals were compared. Median serum progesterone concentrations were higher in progesterone vs placebo-treated rabbits (3.8 [range, 2.8-5.1] vs 0.7 [0.4-1.7] ng/mL, P < 0.0001). Median serum estradiol concentrations were similar (58 [22-72] vs 53 [34-62] pg/mL), P = 0.79). The incidence of TdP was lower in hearts from progesterone-treated rabbits (27% vs 61%, P = 0.049). The incidences of bigeminy (36% vs 74%, P = 0.03) and trigeminy (18% vs 57%, P = 0.01) were also lower in hearts from progesterone-treated rabbits. There was no significant difference between groups in incidence of couplets (59% vs 74%, P = 0.54) or monomorphic ventricular tachycardia (14% vs 30%, P = 0.28). Maximum QT c interval and short-term beat-to-beat QT interval variability during dofetilide perfusion were significantly shorter in hearts from progesterone-treated rabbits. CONCLUSIONS: Pretreatment with progesterone reduces the incidence of drug-induced TdP, bigeminy, and trigeminy in isolated perfused AV node-ablated rabbit hearts.


Assuntos
Nó Atrioventricular/cirurgia , Frequência Cardíaca/efeitos dos fármacos , Fenetilaminas , Progesterona/farmacologia , Sulfonamidas , Torsades de Pointes/prevenção & controle , Potenciais de Ação/efeitos dos fármacos , Animais , Nó Atrioventricular/fisiopatologia , Modelos Animais de Doenças , Estradiol/sangue , Feminino , Terapia de Reposição Hormonal , Preparação de Coração Isolado , Ovariectomia , Progesterona/sangue , Coelhos , Fatores de Tempo , Torsades de Pointes/sangue , Torsades de Pointes/induzido quimicamente , Torsades de Pointes/fisiopatologia
10.
J Thorac Cardiovasc Surg ; 158(1): 301-310.e1, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30853230

RESUMO

OBJECTIVES: Atrial fibrillation (AF) is a common complication after esophagectomy and is associated with symptoms, hemodynamic instability, prolonged hospital stay, and an increased incidence of mortality. Our objective was to determine the efficacy and safety of intravenous amiodarone for prophylaxis of postesophagectomy AF. METHODS: In this retrospective cohort study, 309 patients who underwent esophagectomy formed the initial cohort. Following propensity score-matching, 110 patients who received prophylactic amiodarone 43.75 mg/hour via continuous intravenous infusion over 96 hours (total dose, 4200 mg) were matched to a control group of patients who did not undergo amiodarone prophylaxis (n = 110). The propensity score was obtained using a multivariate logistic regression model with amiodarone as the variable and the following covariates: age, sex, surgical approach, history of neoadjuvant chemotherapy and/or radiation, chronic obstructive pulmonary disease, heart failure, cardiovascular disease, alcohol use (>7 drinks/week), preadmission ß-blockers discontinued during hospitalization, preoperative use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, preoperative use of corticosteroids, postoperative use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, postoperative use of corticosteroids, postoperative use of statins, and preoperative Charlson comorbidity index. RESULTS: The incidence of AF requiring treatment due to rapid ventricular rate and symptoms was lower in the amiodarone group (17 out of 110 [15.5%] vs 32 out of 110 [29.1%]; odds ratio, 0.45; 95% confidence interval, 0.23-0.86; P = .015). There were no significant differences between the groups in median postoperative length of hospital stay, incidence of pulmonary complications, or mortality. The incidences of hypotension requiring treatment (42.7% vs 21.8%; P = .001), bradycardia (8.2% vs 0.0%; P = .002), and corrected QT interval prolongation (10.9% vs 0.0%; P ≤ .0001) were significantly higher in the amiodarone group. CONCLUSIONS: Prophylactic intravenous amiodarone is associated with a reduction in the incidence of AF following esophagectomy, but is not associated with shorter postoperative length of hospital stay. Intravenous amiodarone for prophylaxis of postesophagectomy AF is associated with hypotension, bradycardia, and corrected QT interval prolongation.


Assuntos
Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/prevenção & controle , Esofagectomia/efeitos adversos , Idoso , Amiodarona/administração & dosagem , Amiodarona/efeitos adversos , Antiarrítmicos/administração & dosagem , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/etiologia , Estudos de Casos e Controles , Quimioprevenção/métodos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos Retrospectivos
11.
J Am Geriatr Soc ; 67(7): 1508-1515, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30747995

RESUMO

BACKGROUND: The exponential increase in the number of medications associated with clinically important prolongation of the heart rate-corrected QT interval (QTc) places older adults at increased risk of arrhythmias including life-threatening torsade de pointes (TdP) and sudden death. Risk factors, other than age older than 65 years and female sex, include multiple concurrent drugs that prolong QTc and a variety of underlying predisposing conditions. Although electronic medical records and pharmacy dispensing systems can alert clinicians to the risk of QTc-prolonging therapy, more than 95% of safety alerts are overridden, and many systems have deactivated QTc drug interaction alerts. The clinical consequences, magnitude of the effect, mitigation strategies, and recommended monitoring are not well defined for nursing facility (NF) residents. DESIGN: Narrative review. SETTING: NFs in the United States. PARTICIPANTS: NF residents. RESULTS: Medications known to prolong QTc include selected anti-infectives, antidepressants, urinary anticholinergics, antipsychotics, and cholinesterase inhibitors (eg, donepezil), used commonly in NFs. Drug-drug interactions are a risk when adding a medication that exaggerates the effect or inhibits the metabolism of a QTc-prolonging medication. The vast majority of patients in whom TdP is induced by noncardiac drugs have risk factors that are easily identifiable. CONCLUSIONS: Recommendations are provided to improve standardization and use of drug interaction alerts, evaluate the risk of QTc-prolonging drugs in older adults receiving generally lower doses, validate a QTc risk score addressing complex multimorbidity, garner evidence to guide clinical decision making, avail NFs of access to electrocardiograms and interpretive recommendations, and develop standards of practice for hosting risk discussions with residents and their families. J Am Geriatr Soc, 1-8, 2019.


Assuntos
Síndrome do QT Longo/induzido quimicamente , Casas de Saúde , Polimedicação , Idoso , Humanos , Fatores de Risco
12.
J Cardiovasc Electrophysiol ; 27(10): 1206-1213, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27333947

RESUMO

BACKGROUND: Efavirenz (EFV) has been associated with torsade de pointes despite marginal QT interval lengthening. Since EFV is metabolized by the cytochrome P450 (CYP) 2B6 enzyme, we hypothesized that EFV would lengthen the rate-corrected QT (QTcF) interval in carriers of the CYP2B6*6 decreased functional allele. OBJECTIVE: The primary objective of this study was to evaluate EFV-associated QT interval changes with regard to CYP2B6 genotype and to explore mechanisms of QT interval lengthening. METHODS: EFV was administered to healthy volunteers (n = 57) as a single 600 mg dose followed by multiple doses to steady-state. Subjects were genotyped for known CYP2B6 alleles and ECGs and EFV plasma concentrations were obtained serially. Whole-cell, voltage-clamp experiments were performed on cells stably expressing hERG and exposed to EFV in the presence and absence of CYP2B6 expression. RESULTS: EFV demonstrated a gene-dose effect and exceeded the FDA criteria for QTcF interval prolongation in CYP2B6*6/*6 carriers. The largest mean time-matched differences ∆∆QTcF were observed at 6 hours (14 milliseconds; 95% CI [1; 27]), 12 hours (18 milliseconds; 95% CI [-4; 40]), and 18 hours (6 milliseconds; 95% CI [-1; 14]) in the CYP2B6*6/*6 genotype. EFV concentrations exceeding 0.4 µg/mL significantly inhibited outward hERG tail currents (P < 0.05). CONCLUSIONS: This study demonstrates that homozygous carriers of CYP2B6*6 allele may be at increased risk for EFV-induced QTcF interval prolongation via inhibition of hERG.


Assuntos
Benzoxazinas/efeitos adversos , Citocromo P-450 CYP2B6/genética , Canal de Potássio ERG1/antagonistas & inibidores , Variantes Farmacogenômicos , Bloqueadores dos Canais de Potássio/efeitos adversos , Inibidores da Transcriptase Reversa/efeitos adversos , Torsades de Pointes/induzido quimicamente , Potenciais de Ação , Adolescente , Adulto , Alcinos , Benzoxazinas/sangue , Ciclopropanos , Citocromo P-450 CYP2B6/metabolismo , Relação Dose-Resposta a Droga , Canal de Potássio ERG1/metabolismo , Eletrocardiografia , Feminino , Frequência do Gene , Genótipo , Células HEK293 , Voluntários Saudáveis , Frequência Cardíaca/efeitos dos fármacos , Homozigoto , Humanos , Masculino , Farmacogenética , Fenótipo , Bloqueadores dos Canais de Potássio/sangue , Inibidores da Transcriptase Reversa/sangue , Medição de Risco , Fatores de Risco , Fatores de Tempo , Torsades de Pointes/genética , Torsades de Pointes/metabolismo , Torsades de Pointes/fisiopatologia , Transfecção , Adulto Jovem
15.
Drugs ; 72(12): 1617-30, 2012 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-22834678

RESUMO

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with severe consequences, including symptoms, haemodynamic instability, increased cardiovascular mortality and stroke. While other arrhythmias such as torsades de pointes and sinus bradycardia are more typically thought of as drug induced, AF may also be precipitated by drug therapy, although ascribing causality to drug-associated AF is more difficult than with other drug-induced arrhythmias. Drug-induced AF is more likely to occur in patients with risk factors and co-morbidities that commonly co-exist with AF, such as advanced age, alcohol consumption, family history of AF, hypertension, thyroid dysfunction, sleep apnoea and heart disease. New-onset AF has been associated with cardiovascular drugs such as adenosine, dobutamine and milrinone. In addition, medications such as corticosteroids, ondansetron and antineoplastic agents such as paclitaxel, mitoxantrone and doxorubicin have been reported to induce AF. Whether bisphosphonate drugs are associated with new-onset AF remains controversial and requires further study. The potential contribution of specific drug therapy should be considered when patients present with new-onset AF.


Assuntos
Arritmias Cardíacas/induzido quimicamente , Fibrilação Atrial/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Fatores de Risco
17.
J Cardiovasc Electrophysiol ; 22(3): 325-31, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20731743

RESUMO

INTRODUCTION: Females are at increased risk for torsades de pointes (TdP). Some evidence suggests that progesterone may protect against TdP, but few data exist regarding the effects of progesterone on cardiac repolarization. We determined the effects of progesterone alone and in combination with estradiol on ventricular action potential duration (APD) and triangulation in response to potassium channel inhibition. METHODS AND RESULTS: Female New Zealand white rabbits (n = 30) underwent ovariectomy and were implanted with 21-day sustained release pellets (each n = 6): progesterone; estradiol; progesterone; & estradiol combined; dihydrotestosterone (DHT); and placebo. After 20 days, hearts were excised, mounted, perfused with modified Krebs-Henseleit buffer, and paced at 150 bpm. After baseline measurements, hearts were perfused with quinidine 3 µmol/L. The degree of quinidine-associated prolongation of ventricular APD at 90% repolarization (APD(90) ) in the progesterone group was significantly less than that in the estradiol and the combined estradiol and progesterone groups, and not significantly different than in the DHT group. The degree of prolongation of action potential triangulation (APD(90) - APD(30) ) in hearts from progesterone-treated rabbits was significantly less than that in the estradiol group, and not significantly different from that in hearts from DHT-treated rabbits. There were no significant differences in quinidine effects on ventricular APD(90) or action potential triangulation between hearts exposed to estradiol alone or those exposed to both estradiol and progesterone. CONCLUSIONS: Progesterone protects against prolongation of APD(90) and triangulation associated with potassium channel inhibition. However, progesterone does not attenuate the effects of estradiol on prolongation of ventricular APD(90) associated with potassium channel inhibition.


Assuntos
Estradiol/toxicidade , Terapia de Reposição de Estrogênios/efeitos adversos , Ventrículos do Coração/efeitos dos fármacos , Bloqueadores dos Canais de Potássio/toxicidade , Progesterona/administração & dosagem , Quinidina/toxicidade , Torsades de Pointes/induzido quimicamente , Torsades de Pointes/prevenção & controle , Potenciais de Ação , Animais , Di-Hidrotestosterona/administração & dosagem , Estradiol/administração & dosagem , Estradiol/sangue , Feminino , Ventrículos do Coração/fisiopatologia , Ovariectomia , Progesterona/sangue , Coelhos , Medição de Risco , Fatores Sexuais , Fatores de Tempo , Torsades de Pointes/fisiopatologia
18.
J Thorac Cardiovasc Surg ; 140(1): 45-51, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20381077

RESUMO

OBJECTIVE: Atrial fibrillation is common after esophagectomy. The objective of this study was to determine the efficacy and safety of amiodarone for prevention of atrial fibrillation after transthoracic esophagectomy. METHODS: Eighty patients undergoing transthoracic esophagectomy were randomly, prospectively assigned to receive amiodarone (n = 40) or no prophylaxis (control group, n = 40). Amiodarone-treated patients received the drug by continuous infusion, initiated at the time of induction of anesthesia, at a rate of 0.73 mg/min (43.75 mg/h), and continued for 96 hours (total dose 4200 mg). The primary end point was atrial fibrillation requiring treatment. Secondary end points included any atrial fibrillation lasting longer than 30 seconds and postoperative hospital and intensive care unit stays. RESULTS: There were no significant differences between the amiodarone and control groups in demographic characteristics, comorbid conditions, or preoperative or postoperative use of beta-blockers or calcium-channel blockers. The incidence of atrial fibrillation requiring treatment was lower in the amiodarone group than in the control group (15% vs 40%, P = .02, relative risk reduction 62.5%). There were no significant differences between the amiodarone and control groups in median hospital stay (11 days vs 12 days, P = .31) or median intensive care unit stay (68 hours vs 77 hours, p = .097). There were no significant difference between the groups in the incidences of adverse effects. CONCLUSIONS: Amiodarone prophylaxis significantly reduced the incidence of atrial fibrillation after transthoracic esophagectomy.


Assuntos
Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/prevenção & controle , Esofagectomia/efeitos adversos , Idoso , Amiodarona/efeitos adversos , Amiodarona/análogos & derivados , Amiodarona/sangue , Antiarrítmicos/efeitos adversos , Antiarrítmicos/sangue , Fibrilação Atrial/etiologia , Distribuição de Qui-Quadrado , Cuidados Críticos , Esquema de Medicação , Esofagectomia/métodos , Esofagectomia/mortalidade , Feminino , Humanos , Incidência , Indiana , Infusões Intravenosas , Estimativa de Kaplan-Meier , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento
19.
Semin Thorac Cardiovasc Surg ; 22(4): 310-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21549271

RESUMO

Atrial fibrillation (AF) occurs commonly after noncardiac thoracic surgery, including lobectomy, pneumonectomy and esophagectomy. While not as extensively investigated as AF following cardiac surgery, some strategies for prophylaxis of AF after noncardiac thoracic surgery have been studied. Evidence from prospective, randomized controlled studies supports the use of beta-blockers, diltiazem, amiodarone or magnesium for prevention of AF after pulmonary resection. Limited evidence supports the efficacy of intravenous amiodarone for prevention of AF after esophagectomy. Further study is necessary to determine the safest and most effective methods of prophylaxis of AF after noncardiac thoracic surgery, and to identify patients most likely to benefit from AF prophylaxis.


Assuntos
Fibrilação Atrial/prevenção & controle , Esofagectomia/efeitos adversos , Pneumonectomia/efeitos adversos , Antagonistas Adrenérgicos beta/uso terapêutico , Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/etiologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Humanos , Cuidados Pós-Operatórios , Fatores de Risco
20.
Ann Thorac Surg ; 88(3): 886-93; discussion 894-5, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19699916

RESUMO

BACKGROUND: Atrial fibrillation (AF) occurs commonly after anatomic pulmonary resection. In this study, the efficacy of amiodarone for prevention of post-pulmonary resection AF was investigated. METHODS: One hundred thirty patients undergoing lobectomy, bilobectomy, or pneumonectomy were randomly assigned prospectively to receive amiodarone (n = 65) or no prophylaxis (control group, n = 65). The amiodarone group received 1,050 mg by continuous intravenous infusion over 24 hours, initiated at the time of anesthesia induction, followed by 400 mg orally twice daily until hospital discharge or for a maximum of 6 days. The primary endpoint was AF requiring treatment during hospitalization. Secondary endpoints included postoperative length of hospital and intensive care unit stays. RESULTS: There were no significant differences between the amiodarone and control groups in demographics, comorbid conditions, extent of pulmonary resection, or preoperative or postoperative use of beta-blockers or calcium-channel blockers. The incidence of AF was lower in the amiodarone group than in the control group (13.8% versus 32.3%, p = 0.02; relative risk reduction = 57%). There was no difference between the amiodarone and control groups in median length of hospital stay (7 versus 8 days, p = 0.79), but median length of intensive care unit stay was shorter in the amiodarone group (46 versus 84 hours, p = 0.03). There was no significant difference between the amiodarone and control groups in the incidence of pulmonary complications or other adverse effects. CONCLUSIONS: Amiodarone prophylaxis significantly reduces the incidence of AF after anatomic pulmonary resection, and is associated with a significant reduction in length of intensive care unit stay.


Assuntos
Amiodarona/administração & dosagem , Antiarrítmicos/administração & dosagem , Fibrilação Atrial/prevenção & controle , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Pneumopatias/cirurgia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Pneumonectomia , Complicações Pós-Operatórias/prevenção & controle , Administração Oral , Idoso , Amiodarona/efeitos adversos , Antiarrítmicos/efeitos adversos , Eletrocardiografia/efeitos dos fármacos , Feminino , Humanos , Infusões Intravenosas , Unidades de Terapia Intensiva , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Pré-Medicação , Estudos Prospectivos
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