1
|
Singh BN, Wadhani N. Antiarrhythmic and Proarrhythmic Properties of QT-Prolonging Antianginal Drugs. J Cardiovasc Pharmacol Ther 2016; 9 Suppl 1:S85-97. [PMID: 15378133 DOI: 10.1177/107424840400900107] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In recent years there has been a major reorientation of drug therapy for cardiac arrhythmias, its changing role, and above all, a radical change in the class of arrhythmia drugs because of their impact on mortality. The decline in the use of sodium-channel blockers has led to an expanding use of β-blockers and simple or complex class III agents for controlling cardiac arrhythmias. Success with these agents in the context of their side effects has spurred the development of compounds with simpler ion-channel blocking properties that have less complex adverse reactions. The resulting so-called pure class III agents, such as dofetilide or ibutilide, were found to have antifibrillatory effects in atrial fibrillation and flutter and in ventricular tachyarrhythmias. Such agents are effective and have diversity, but they have come into therapeutics with a price: the sometimes-fatal torsades de pointes. The drug amiodarone, a complex compound that was synthesized as an antianginal agent, has been an exception in this regard. Its therapeutic use is associated with a negligibly low incidence of torsades de pointes, even though the drug produces significant bradycardia and QT lengthening to 500 to 700 msec. Recent electrophysiologic studies suggest that this paradox is likely due to the differential block of ion channels in endocardium, epicardium, midmyocardial (M) cells, and Purkinje fibers in the ventricular myocardium. There is also clinical evidence suggesting that amiodarone reduces the “torsadogenic” effects of pure class III agents. Ranolazine was also synthesized for the development of antianginal properties that stem from a partial inhibition of fatty acid oxidation; it too has been found to have electrophysioloigic properties. These are somewhat similar to those of amiodarone on ion channels in endocardium, epicardium, M cells, and Purkinje fibers in the ventricular myocardium, but the drug does not prolong the QT interval to the same extent as amiodarone does. Thus, the drug produces modest increases in repolarization as judged by its effects on the action potential duration (APD) without the potential for the development of torsades de pointes. By virtue of its suppressant action on early afterdepolarizations and triggered activity in Purkinje fibers and M cells, the drug appears to have a powerful potential for reducing the torsadogenic proclivity of conventional class III antiarrhythmic compounds. The rationale for the therapeutic niche for amiodarone, and especially in the case of ranolazine, in the prevention of drug-induced torsades de pointes is discussed.
Collapse
Affiliation(s)
- Bramah N Singh
- Division of Cardiology, Veterans Administration Greater Los Angeles Healthcare System and the David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90073, USA.
| | | |
Collapse
|
2
|
Bickford CL, Agarwal R, Urbauer DL, Durand JB, Lenihan DJ. Efficacy and safety of ibutilide for chemical cardioversion of atrial fibrillation and atrial flutter in cancer patients. Am J Med Sci 2014; 347:277-81. [PMID: 23588261 DOI: 10.1097/maj.0b013e31828a7656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Atrial fibrillation and atrial flutter (AF/AFL) are the most common arrhythmias encountered in clinical practice. Rate versus rhythm control remains a difficult decision, especially in the acute setting. Ibutilide is a class III antiarrhythmic indicated for pharmacological cardioversion of recent-onset AF/AFL. At the University of Texas MD Anderson Cancer Center, restoration of sinus rhythm is desirable because many patients have contraindications to anticoagulation. In addition, most are on multiple medications that prolong the QT interval; therefore, the objective of this study was to establish the safety and efficacy of ibutilide. METHODS This was a retrospective chart review of 81 patients who were identified via the pharmacy database as receiving ibutilide for AF/AFL from January 2002 to May 2006. Outcomes including cardioversion rates and effects on the QT interval were recorded. RESULTS Ibutilide use was associated with successful cardioversion in 75% of patients. Out of 81 patients, 68 patients (84%) were on at least 1 medication that prolonged the QT interval at the time of ibutilide administration. However, no significant changes in the corrected QT interval pre and post ibutilide cardioversion were noted in any group of patients. CONCLUSIONS Overall, ibutilide is safe and effective in cancer patients when used for acute cardioversion of AF/AFL. Despite the use of multiple medications that can potentially prolong the QT interval, no patient experienced serious life-threatening rhythm disturbances or significant QT prolongation during ibutilide administration.
Collapse
Affiliation(s)
- Courtney L Bickford
- Division of Pharmacy (CLB), Departments of Cardiology (RA, J-BD) and Biostatistics (DLU), University of Texas MD Anderson Cancer Center, Houston, Texas; and Division of Cardiovascular Medicine (DJL), Vanderbilt University, Nashville, Tennessee
| | | | | | | | | |
Collapse
|
3
|
Camm AJ, Toft E, Torp-Pedersen C, Vijayaraman P, Juul-Moller S, Ip J, Beatch GN, Dickinson G, Wyse DG. Efficacy and safety of vernakalant in patients with atrial flutter: a randomized, double-blind, placebo-controlled trial. Europace 2012; 14:804-9. [DOI: 10.1093/europace/eur416] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
4
|
SINGH SHELDONM, D'AVILA ANDRE, KIM YOUNGHOON, ARYANA ARASH, MANGRUM JMICHAEL, MICHAUD GREGORYF, DUKKIPATI SRINIVASR, CALLANS DAVIDJ, BARRETT CONORD, BERAS-JOVINE MAXIMOR, REDDY VIVEKY. The Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF) Study: Clinical Background and Study Design. J Cardiovasc Electrophysiol 2011; 23:352-8. [DOI: 10.1111/j.1540-8167.2011.02198.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
5
|
Abstract
INTRODUCTION Atrial fibrillation (AF) is associated with increased mortality and morbidity. Although stroke prevention is the only way to improve prognosis, antiarrhythmic drugs (AADs) are of primary importance both in the conversion to sinus rhythm and in the long-term control of rhythm and rate. AREAS COVERED We searched the Cochrane Library and Medline Database for articles published in English concerning efficacy and safety of AADs in AF. Particular attention was paid to the recently published European Society of Cardiology guidelines. This review provides an overview of the currently available drugs used in AF, with a particular emphasis on their comparative efficacy and safety in different kind of patients. Recent important findings, and advantages and disadvantages of recently approved drugs such as vernakalant and dronedarone, are also discussed. EXPERT OPINION AADs remain fundamental in the acute and long-term management of AF, to control symptoms and to reduce the negative impact of the arrhythmia on QoL. The choice of a rate- over rhythm-control strategy should be individualized and based on accurate evaluation of patient medical history and symptoms. New agents will contribute to improve treatment efficacy together with the guarantee of better safety profiles.
Collapse
Affiliation(s)
- Alessandro Marinelli
- Clinica di Cardiologia , Università Politecnica delle Marche, Ospedali Riuniti di Ancona, Italy.
| | | |
Collapse
|
6
|
Sicouri S, Carlsson L, Antzelevitch C. Electrophysiologic and antiarrhythmic effects of AZD1305 in canine pulmonary vein sleeves. J Pharmacol Exp Ther 2010; 334:255-9. [PMID: 20360353 PMCID: PMC2912040 DOI: 10.1124/jpet.110.166702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to examine the electrophysiologic and antiarrhythmic effects of the new antiarrhythmic agent tert-butyl (2-[7-[2-(4-cyano-2-fluorophenoxy)ethyl]-9-oxa-3,7-diazabicyclo[3.3.1]non3-yl]ethyl)carbamate (AZD1305) in canine pulmonary vein (PV) sleeve preparations isolated from untreated and long-term amiodarone-treated animals. Ectopic activity arising from PV sleeves plays a prominent role in the development of atrial fibrillation (AF). Delayed afterdepolarizations (DADs) and late phase 3 early afterdepolarizations (EADs), originating from the PV have been proposed as potential triggers in initiation of AF. Action potentials were recorded from canine superfused PV sleeves using standard microelectrode techniques. Acetylcholine (1 microM), isoproterenol (1 microM), or their combination was used to induce EADs, DADs, and triggered activity (TA). The effects of AZD1305 (0.1-10 microM) were evaluated in PV sleeve preparations isolated from untreated and amiodarone-treated (40 mg/kg daily for 6 weeks) dogs. AZD1305 (0.1-10 microM, 30 min) significantly prolonged action potential duration and reduced excitability. Abbreviating basic cycle length from 1000 to 300 ms resulted in a decrease of V(max) from 314 +/- 79 to 251 +/- 55 V/s (Delta = -20%) in control and from 177 +/- 53 to 76.5 +/- 33 V/s (Delta = -57%) after AZD1305 (n = 6, p < 0.05). AZD1305 markedly attenuated or suppressed DADs and DAD-induced TA, but not late phase 3 EADs. AZD1305-induced attenuation of excitability, leading to activation failure at much longer cycle lengths, was much more pronounced in PV from amiodarone-treated dogs. Potent effects of AZD1305 to depress excitability, prolong action potential duration, and suppress DAD-induced triggered activity in canine PV sleeve preparations may be effective in suppressing triggers responsible for the genesis of AF and other atrial arrhythmias.
Collapse
Affiliation(s)
- Serge Sicouri
- Masonic Medical Research Laboratory, Utica, NY 13501, USA.
| | | | | |
Collapse
|
7
|
Li EC, Esterly JS, Pohl S, Scott SD, McBride BF. Drug-Induced QT-Interval Prolongation: Considerations for Clinicians. Pharmacotherapy 2010; 30:684-701. [DOI: 10.1592/phco.30.7.684] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
8
|
Fragakis N, Bikias A, Delithanasis I, Konstantinidou M, Liakopoulos N, Kozirakis M, Katsaris G. Acute beta-adrenoceptor blockade improves efficacy of ibutilide in conversion of atrial fibrillation with a rapid ventricular rate. Europace 2008; 11:70-4. [DOI: 10.1093/europace/eun302] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
9
|
MORITA NORISHIGE, KOBAYASHI YOSHINORI, IWASAKI YUKI, HAYASHI MEISO, MIYAUCHI YASUSHI, ATARASHI HIROTSUGU, TANAKA KEIJI, KATOH TAKAO, MIZUNO KYOICHI. Characterization of Transient Atrial Rhythm Occurring between Typical Atrial Flutter and Its Termination with Class III Drugs. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2008; 31:943-54. [DOI: 10.1111/j.1540-8159.2008.01120.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
10
|
Abstract
Prolongation of the ventricular repolarisation manifests itself as a prolongation of the QT intervall on the surface ECG and represents a major risk for a special form of ventricular tachycardia called "torsades de pointes". Torsades de pointes are often self limited and are associated with palpitations, dizziness or syncope. Degeneration into ventricular fibrillation and sudden cardiac death can occur. In addition to the various forms of the congenital long QT syndrome many drugs, such as antiarrhythmic drugs class IA and III, antibiotics, antihistamines, antidepressants, and methadone are known to prolong the QT interval. Most of these drugs block a specific potassium channel substantially involved in the ventricular repolarisation. In addition, drug interaction or disturbances of drug metabolism may play a major role in the acquired form of the long QT syndrome. The individual risk and the potential of a pharmacologic substance to prolong the QT interval are not predictable. Certain risk factors identify patients at higher risk for drug-induced prolongation of the QT interval. Correctable factors include electrolyte disorders (e.g. hypokalemia) and concomitant administration of different QT prolonging drugs. External defibrillation is the therapy of choice in the hemodynamic unstable patient presenting torsades de pointes. In hemodynamic more stable patients application of intravenous magnesium can terminate torsades de pointes (membrane stabilizing properties). Temporary external or transvenous pacing at high heart rate might terminate incessant torsades de pointes by decreasing QT interval. Repeated ECG controls during therapy with QT prolonging drugs are mandatory, especially when drug doses are changed, additional drugs are prescribed, or in case of vomiting and diarrhea. QT prolongation in individual medical therapy is not always predictable. Therefore, updated lists of drugs with the potential of QT prolongation are available on the Internet (e.g. www.qtdrugs.org ).
Collapse
|
11
|
TERCIUS ALIXJ, KLUGER JEFFREY, COLEMAN CRAIGI, MICHAEL WHITE C. Intravenous Magnesium Sulfate Enhances the Ability of Intravenous Ibutilide to Successfully Convert Atrial Fibrillation or Flutter. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:1331-5. [DOI: 10.1111/j.1540-8159.2007.00866.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
Morita N, Tanaka K, Yodogawa K, Hayashi M, Akutsu K, Yamamoto T, Satoh N, Kobayashi Y, Katoh T, Takano T. Effect of nifekalant for acute conversion of atrial flutter: the possible termination mechanism of typical atrial flutter. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:1242-53. [PMID: 17897127 DOI: 10.1111/j.1540-8159.2007.00846.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Nifekalant is a class III antiarrhythmic drug, which is usually used for suppression of ventricular tachycardia (VT) and fibrillation. We studied the efficacy of nifekalant for acute conversion of atrial flutter (AFL) in a prospective, open label study in the intensive care unit (ICU) of cardiovascular medicine. METHODS This study consisted of 31 patients. Twenty-six patients (84%) suffered from structural heart diseases. AFL was developed in 15 patients (48%) while on antiarrhythmic therapy with class IA or IC drugs (I-AFL group) for suppressing atrial fibrillation (AF) and in the remaining patients without such drugs (S-AFL group). Patients with prolonged QT interval, hypokalemia were excluded. All patients received one dose of 0.3 mg/kg of nifekalant over 10 minutes under continuous ambulatory monitoring. Four patients with common AFL in each group received nifekalant during electrophysiologic (EP) study. RESULTS Nifekalant had an overall AFL conversion efficacy of 77.4% within 60 minutes. Eleven patients in S-AFL group (68.8%) and 13 patients in I-AFL group (86.7%) could be converted with mean conversion times of 10.8 +/- 6.2 and 15.0 +/- 8.0 minutes, respectively (n.s.). Conversion rate was significantly higher in patients with a short duration of arrhythmia. The two modes of AFL termination were mainly demonstrated and the preferential mode significantly differed between the two groups. One patient in each group with excessive QT prolongation (6.5%) developed torsade de pointes (TdP), requiring electrical shock in one patient (3.3%). CONCLUSIONS Nifekalant can be used for conversion of AFL with a potent efficacy even in patients with structural heart diseases. However, caution should be required for developing TdP.
Collapse
Affiliation(s)
- Norishige Morita
- Intensive and Coronary Care Unit, Nippon Medical School, Tokyo, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Shah SA, Kluger J, White CM. Monotherapy versus Combination Therapy with Class III Antiarrhythmic Agents to Attenuate Transmural Dispersion of Repolarization: A Potential Risk Factor for Torsade de Pointes. Pharmacotherapy 2007; 27:1297-305. [PMID: 17723083 DOI: 10.1592/phco.27.9.1297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Class III antiarrhythmic agents are used for conversion to and maintenance of sinus rhythm from arrhythmias of atrial or ventricular origin. Monotherapy can be limited by adverse events or recurrent arrhythmias. Sotalol, dofetilide, and ibutilide may induce torsade de pointes in 2-8% of patients, whereas amiodarone induces torsade de pointes in less than 1%. We reviewed the literature regarding the possible combination of class III antiarrhythmics and risk for inducing torsade de pointes. Animal studies using amiodarone plus sotalol or d-sotalol suggest that these drug combinations prolong the QTc interval but do not induce torsade de pointes. Similar data extracted from human studies of ibutilide in patients also receiving amiodarone or sotalol showed greater efficacy with combination therapy than with monotherapy, without increased torsade de pointes induction. Reduced transmural dispersion of repolarization with amiodarone and sotalol combination therapy may serve as a mechanism for reducing the risk of torsade de pointes compared with sotalol monotherapy.
Collapse
Affiliation(s)
- Sachin A Shah
- Department of Drug Information, Hartford Hospital, Hartford, Connecticut 06102-5037, USA
| | | | | |
Collapse
|
14
|
Singh BN, Aliot E. Newer antiarrhythmic agents for maintaining sinus rhythm in atrial fibrillation: simplicity or complexity? Eur Heart J Suppl 2007. [DOI: 10.1093/eurheartj/sum049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
15
|
Hoyer AW, Balaji S. The Safety and Efficacy of Ibutilide in Children and in Patients with Congenital Heart Disease. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:1003-8. [PMID: 17669084 DOI: 10.1111/j.1540-8159.2007.00799.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The safety and efficacy of ibutilide in the cardioversion of atrial flutter and atrial fibrillation in children and in patients with congenital heart disease (CHD) is unknown. METHODS Data from 19 patients (age 6 months to 34 years, median 16 years) who received ibutilide for atrial flutter or atrial fibrillation between 1996 and 2005 was retrospectively reviewed. There were 15 patients with CHD (14 had prior heart surgery); four children had normal heart structure. RESULTS There were 74 episodes of atrial flutter and four episodes of atrial fibrillation (median episodes per patient was one, range 1-31). Ibutilide converted 55 of all the episodes (71%). Ibutilide was successful during its first-ever administration in 12 of 19 patients (63%). Fourteen episodes in six patients required electrical cardioversion after ibutilide failed. There were no episodes of symptomatic bradycardia. One patient went into torsade de pointes and one patient had nonsustained ventricular tachycardia. CONCLUSION With careful monitoring, ibutilide can be an effective tool in selected patients for cardioversion of atrial flutter.
Collapse
Affiliation(s)
- Andrew W Hoyer
- Department of Pediatrics, Division of Pediatric Cardiology, Oregon Health & Science University, Portland, OR 97239, USA
| | | |
Collapse
|
16
|
Sideris S, Bonios M, Melexopoulou C, Exarchos P, Tsatiris K, Kogias J. The role of amiodarone in recent-onset atrial fibrillation after ibutilide has failed to restore sinus rhythm. Cardiology 2007; 107:399-401. [PMID: 17284902 DOI: 10.1159/000099059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 07/10/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND Ibutilide is a class III antiarrhythmic drug that is used for the cardioversion of atrial arrhythmias, but it can cause torsades de pointes. Amiodarone is also used for the cardioversion of atrial fibrillation and prolongs the QT interval but rarely causes torsades de pointes. METHODS AND RESULTS The study included 51 consecutive patients with recent onset atrial fibrillation in whom the administration of ibutilide failed to restore sinus rhythm. In those patients we decided to proceed to intravenous administration of amiodarone. The QT intervals were measured on 12-lead ECG. After 11 +/- 5 h of the administration of the amiodarone, 42 patients (82%) were on sinus rhythm. There was no episode of non-sustained torsades de pointes or hypotension that followed the administration of the two antiarrhythmic agents. CONCLUSIONS The administration of amiodarone in the case of ibutilide failure may be a useful adjunct to current cardioversion protocols for recent onset atrial fibrillation.
Collapse
Affiliation(s)
- S Sideris
- Cardiology Department, General Hospital of Karditsa, Karditsa, Greece.
| | | | | | | | | | | |
Collapse
|
17
|
|
18
|
Abstract
Synthesized as an antianginal compound 40 years ago, amiodarone has emerged as a uniquely effective antiarrhythmic compound in recent years. It has numerous properties, the most prominent being the ability to lengthen repolarization in the atria and ventricles associated with bradycardia without the significant potential for torsades de pointes. Amiodarone effectively controls a wide spectrum of atrial and ventricular antiarrhythmic disorders, but its limiting side effects, such as thyroid dysfunction, pulmonary fibrosis, and dermatologic changes, may limit its long-term use in some patients. What aspects of the multiplicity of the properties of amiodarone are relevant to its unusual efficacy is not known. Deiodination and other structural changes in the amiodarone molecule have has led to a the loss of thyroid and pulmonary effects in the resulting derivative, dronedarone, which is in advanced clinical development.
Collapse
Affiliation(s)
- Bramah N Singh
- Cardiology Division, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, West Los Angeles, CA 90073, USA.
| |
Collapse
|
19
|
Olshansky B, Guo H. Acute anticoagulation adjustment in patients with atrial fibrillation at risk for stroke: approaches, strategies, risks and benefits. Expert Rev Cardiovasc Ther 2006; 3:571-90. [PMID: 16076269 DOI: 10.1586/14779072.3.4.571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The acute management of anticoagulation in patients with atrial fibrillation to prevent stroke and other thromboembolic complications includes the use of individualized strategies tailored to the patient and based on the situation (cardioversion, surgeries, dental procedures, cardiac interventions, other invasive procedures and initiation of, or adjustment to, warfarin dosing). The vast range of choices can cause confusion and few randomized controlled clinical trials in this area provide adequate guidance. Chronic anticoagulation management is more straightforward since clinical evidence is ample, randomized clinical trial data provides cogent informaiton and guidelines have been established. Acute management of anticoagulation in patients with atrial fibrillation to prevent thromboembolic complications is often unrecognized but is emerging as a crucial, but challenging, and increasingly complex aspect of the care of patients with atrial fibrillation. This review addresses issues regarding such patients who may be at risk for stroke and require acute adjustments of anticoagulation (in light of, or in lieu of, chronic anticoagulation). Several promising new strategies are considered in light of established medical care. This analysis provides practical recommendations based on available data and presents results from recent investigations that may provide insight into future strategies.
Collapse
Affiliation(s)
- Brian Olshansky
- Cardiac Electrophysiology, University of Iowa Hospitals, 4426A JCP, 200 Hawkins Drive, Iowa City, IA 52242, USA.
| | | |
Collapse
|
20
|
Eidher U, Freihoff F, Kaltenbrunner W, Steinbach K. Efficacy and Safety of Ibutilide for the Conversion of Monomorphic Atrial Tachycardia. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2006; 29:358-62. [PMID: 16650262 DOI: 10.1111/j.1540-8159.2006.00353.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ibutilide is a class III antiarrhythmic drug, frequently used for conversion of atrial fibrillation and flutter. We studied the efficacy of ibutilide for acute conversion of monomorphic atrial tachycardia (monoAT) in a prospective, open label study in the intensive care unit of a cardiological clinic. METHODS We examined 49 episodes of monoAT in 38 patients (19 men/19 women). Thirty-three patients (87%) suffered from structural heart disease. Twenty-three episodes occurred while on antiarrhythmic therapy with class I or III drugs. Patients with prolonged QT interval (except for patients with pretreatment with class III drugs), hypokalemia, left ventricular failure, and recent myocardial infarction were excluded. All patients received one or two doses of 1 mg ibutilide fumarate under continuous rhythm monitoring. RESULTS Conversion to sinus rhythm occurred in 19 episodes (38.8%), in 6 episodes (12.2%) after the first dose. Conversion rate was significantly higher in patients with a short history of symptoms (66.6% vs 28.6%; P < 0.05), of documented arrhythmia (0.13 (0/5.7) vs 2.6 (0.38/23.5) months, median (interquartile range); P < 0.03), higher atrial rate (272 +/- 49 vs 207 +/- 36 beats/min (means +/- SD); P < 0.004), or without preexisting antiarrhythmic therapy (53.8% vs 21.7%; P < 0.02). No differences in conversion rates were found regarding gender, age, body mass index, left ventricular function, left atrial diameter, or underlying disease. In three episodes torsade de pointes occurred after ibutilide (6.1%), requiring defibrillation in two cases (4.1%). CONCLUSIONS Ibutilide can be used for conversion of monoAT with a similar efficacy as for atrial fibrillation, but with a considerably lower efficacy compared to typical atrial flutter.
Collapse
Affiliation(s)
- Ulrike Eidher
- Ludwig-Boltzmann Institute for Arrhythmia Research, Department of Internal Medicine 3 (Cardiology), Wilhelminenspital, Vienna, Austria.
| | | | | | | |
Collapse
|
21
|
Affiliation(s)
- Etienne Delacrétaz
- Swiss Cardiovascular Centre Bern, University Hospital Bern, Bern, Switzerland.
| |
Collapse
|
22
|
Korantzopoulos P, Kolettis TM, Papathanasiou A, Naka KK, Kolios P, Leontaridis I, Draganigos A, Katsouras CS, Goudevenos JA. Propafenone added to ibutilide increases conversion rates of persistent atrial fibrillation. Heart 2005; 92:631-4. [PMID: 16159973 PMCID: PMC1860948 DOI: 10.1136/hrt.2005.072322] [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: 11/03/2022] Open
Abstract
OBJECTIVE To assess the effectiveness and safety of pharmacological conversion of persistent atrial fibrillation (AF) with a combined propafenone plus ibutilide regimen. METHODS AND RESULTS 100 consecutive patients (66 men, mean (SD) age 65 (10) years) with persistent AF (mean (SD) duration 99 (92) days) admitted for elective pharmacological cardioversion were randomly assigned to treatment with either intravenous ibutilide (1 mg plus an additional 1 mg, if required; n = 51) or oral propafenone (600 mg) plus intravenous ibutilide at the same dose (n = 49). Success rates were 41.1% (21 of 51 patients) for ibutilide alone and 71.4% (35 of 49 patients) for propafenone plus ibutilide (p = 0.0044). However, cardioversion occurred earlier in the ibutilide alone group (55 (20) minutes) compared with the combination group (81 (32) minutes, p = 0.0019). A comparable increase in the QTc interval was observed in both groups but one case of sustained torsade de pointes, requiring electrical cardioversion, was observed in the propafenone plus ibutilide group. No other complications were noted during the hospitalisation period. CONCLUSION Concurrent administration of propafenone plus ibutilide for pharmacological cardioversion of persistent AF is safe and more effective than ibutilide alone.
Collapse
Affiliation(s)
- P Korantzopoulos
- Department of Cardiology, University of Ioannina Medical School, 45110 Ioannina, Greece.
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Fragakis N, Papadopoulos N, Papanastasiou S, Kozirakis M, Maligkos G, Tsaritsaniotis E, Katsaris G. Efficacy and Safety of Ibutilide for Cardioversion of Atrial Flutter and Fibrillation in Patients Receiving Amiodarone or Propafenone. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2005; 28:954-61. [PMID: 16176535 DOI: 10.1111/j.1540-8159.2005.00212.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM The effectiveness and safety of ibutilide (IB) use in patients receiving amiodarone or propafenone for atrial flutter (AFL) and atrial fibrillation (AF) were compared to IB alone. METHODS AND RESULTS In 104 consecutive patients with AF (65%) or AFL (35%), receiving amiodarone (n = 46), propafenone (n = 30), or no specific antiarrhythmic drug (n = 28), IB was given for cardioversion. Fifteen patients in amiodarone group were loaded with 1.2 g intravenously before IB administration. The mean duration of arrhythmia episode was 23 +/- 65 days, while 85% of patients had structural heart disease. The left ventricle ejection fraction was 57 +/- 10% and the left atrium size was 4.2 +/- 0.6 cm. The conversion efficacy did not differ among groups (62% for amiodarone vs 55% for propafenone vs 64% for IB alone). The QTc intervals were significantly prolonged, at 10 minutes and 30 minutes after IB administration, in amiodarone group (from 449 +/- 88 to 496 +/- 92 ms, 508 +/- 52 ms; P = 0.001) and in the group where IB was used alone (from 434 +/- 45 to 517 +/- 74 ms, 492 +/- 65 ms; P < 0.001), while it remained unchanged in propafenone group (from 464 +/- 52 to 471 +/- 80 ms, 489 +/- 93 ms; P = 0.536). The only predictor of conversion was the presence of AFL (P = 0.009). Five patients developed ventricular tachycardias after IB administration (two in propafenone, one in amiodarone, and two in IB group). CONCLUSIONS The use of IB in patients receiving amiodarone or propafenone for AFL or AF is equally effective and safe as the use of IB alone. The presence of AFL is the stronger predictor factor for cardioversion.
Collapse
Affiliation(s)
- Nikolaos Fragakis
- 2nd Cardiac Department, GH G. Papanikolaou, Kromnis 42, 55131 Thessaloniki, Greece.
| | | | | | | | | | | | | |
Collapse
|
24
|
Antzelevitch C, Belardinelli L, Wu L, Fraser H, Zygmunt AC, Burashnikov A, Di Diego JM, Fish JM, Cordeiro JM, Goodrow RJ, Scornik F, Perez G. Electrophysiologic properties and antiarrhythmic actions of a novel antianginal agent. J Cardiovasc Pharmacol Ther 2005; 9 Suppl 1:S65-83. [PMID: 15378132 DOI: 10.1177/107424840400900106] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ranolazine is a novel antianginal agent capable of producing anti-ischemic effects at plasma concentrations of 2 to 6 microM without a significant reduction of heart rate or blood pressure. This review summarizes the electrophysiologic properties of ranolazine. Ranolazine significantly blocks I(Kr) (IC(50) = 12 microM), late I(Na), late I(Ca), peak I(Ca), I(Na-Ca) (IC(50) = 5.9, 50, 296, and 91 microM, respectively) and I(Ks) (17% at 30 microM), but causes little or no inhibition of I(to) or I(K1). In left ventricular tissue and wedge preparations, ranolazine produces a concentration-dependent prolongation of action potential duration (APD) in epicardium, but abbreviation of APD of M cells, leading to either no change or a reduction in transmural dispersion of repolarization (TDR). The result is a modest prolongation of the QT interval. Prolongation of APD and QT by ranolazine is fundamentally different from that of other drugs that block I(Kr) and induce torsade de pointes in that APD prolongation is rate-independent (ie, does not display reverse rate-dependent prolongation of APD) and is not associated with early after depolarizations, triggered activity, increased spatial dispersion of repolarization, or polymorphic ventricular tachycardia. Torsade de pointes arrhythmias were not observed spontaneously nor could they be induced with programmed electrical stimulation in the presence of ranolazine at concentrations as high as 100 microM. Indeed, ranolazine was found to possess significant antiarrhythmic activity, acting to suppress the arrhythmogenic effects of other QT-prolonging drugs. Ranolazine produces ion channel effects similar to those observed after chronic exposure to amiodarone (reduced late I(Na), I(Kr), I(Ks), and I(Ca)). Ranolazine's actions to reduce TDR and suppress early after depolarization suggest that in addition to its anti-anginal actions, the drug possesses antiarrhythmic activity.
Collapse
|
25
|
Naegeli B, Straumann E, Bertel O. Ibutilide in persistent atrial fibrillation refractory to conventional cardioversion methods. Int J Cardiol 2005; 99:283-7. [PMID: 15749188 DOI: 10.1016/j.ijcard.2004.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Revised: 01/06/2004] [Accepted: 01/08/2004] [Indexed: 11/20/2022]
Abstract
BACKGROUND Electrical cardioversion of atrial fibrillation seems to be enhanced by pretreatment with ibutilide, but only few is known about the effects of ibutilide in atrial fibrillation which failed to convert with class III antiarrhythmic agents and electrical cardioversion. The objectives of this study were to evaluate the efficacy and safety of ibutilide administration in patients with persistent atrial fibrillation refractory to long-term therapy with class III antiarrhythmic drugs and transthoracic cardioversion. METHODS Prospective study in 22 patients (16 men and 6 women, mean age 63+/-9 years) with structural heart disease and persistent atrial fibrillation for a mean duration of 39+/-50 (range 1-145) months. All patients had failed to convert to sinus rhythm after transthoracic cardioversion while on treatment with class III antiarrhythmic drugs (amiodarone in 82%, sotalol in 18%). One milligram of ibutilide was administered in all patients and electrical cardioversion was performed again, if necessary. RESULTS The total conversion rate to sinus rhythm was 95% (21 of 22 patients). Two patients (9%) were successfully converted after ibutilide alone and 19 patients (86%) when transthoracic cardioversion was repeated after ibutilide. The QTc intervals increased from 451+/-28 to 491+/-49 ms (p<0.001) after ibutilide. No adverse effects occurred. The rate of freedom from atrial fibrillation after 1 month of follow-up was 64%. CONCLUSIONS The efficacy of concomitant use of ibutilide infusion and, if necessary, repeated transthoracic cardioversion for restoration of sinus rhythm in long-term persistent atrial fibrillation and previously failed antiarrhythmic and electrical cardioversion was 95%. There were no adverse effects associated with ibutilde administration. Our results suggest that this combined strategy may be safe and successful in patients with atrial fibrillation resistant to conventional cardioversion methods and may be an alternative to internal cardioversion.
Collapse
Affiliation(s)
- Barbara Naegeli
- Cardiac Unit, Department of Internal Medicine, Stadtspital Triemli, Birmensdorferstr. 497, CH-8063 Zürich, Switzerland.
| | | | | |
Collapse
|
26
|
Doggrell SA, Hancox JC. Ibutilide – recent molecular insights and accumulating evidence for use in atrial flutter and fibrillation. Expert Opin Investig Drugs 2005; 14:655-69. [PMID: 15926871 DOI: 10.1517/13543784.14.5.655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Ibutilide is a 'pure' class III antiarrhythmic drug, used intravenously against atrial flutter and fibrillation. At a cellular level it exerts two main actions: induction of a persistent Na+ current sensitive to dihydropyridine Ca2+ channel blockers and potent inhibition of the cardiac rapid delayed rectifier K+ current, by binding within the channel pore cavity upon channel gating. Ibutilide has been shown to terminate atrial flutter and fibrillation in animal studies, with some risk of ventricular pro-arrhythmia. Experimental models of hypertrophy/heart failure show altered sensitivity to ibutilide, with increased dispersion of repolarisation and incidence of pro-arrhythmia. Patient trials show that ibutilide is effective at terminating atrial arrhythmias when given alone, and that it can increase effectiveness and reduce energy requirements of electrical cardioversion. The risk to patients of polymorphic ventricular tachycardia necessitates careful patient selection and monitoring during and after treatment. An ibutilide analogue, trecetilide, requires further investigation but may offer a less readily metabolised and pro-arrhythmic alternative to ibutilide.
Collapse
Affiliation(s)
- Sheila A Doggrell
- Doggrell Biomedical Communications, 47 Caronia Crescent, Lynfield, Auckland, New Zealand
| | | |
Collapse
|
27
|
Elming H, Brendorp B, Pehrson S, Pedersen OD, Køber L, Torp-Petersen C. A benefit–risk assessment of class III antiarrhythmic agents. Expert Opin Drug Saf 2005; 3:559-77. [PMID: 15500415 DOI: 10.1517/14740338.3.6.559] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The prevalence of arrhythmia in the population is increasing as more people survive for longer with cardiovascular disease. It was once thought that antiarrhythmic therapy could save life, however, it is now evident that antiarrhythmic therapy should be administrated with the purpose of symptomatic relief. Since many patients experience a decrease in physical performance as well as a diminished quality of life during arrhythmia there is still a need for antiarrhythmic drug therapy. The development of new antiarrhythmic agents has changed the focus from class I to class III agents since it became evident that with class I drug therapy the prevalence of mortality is considerably higher. This review focuses on the benefits and risks of known and newer class III antiarrhythmic agents. The benefits discussed include the ability to maintain sinus rhythm in persistent atrial fibrillation patients, and reducing the need for implantable cardioverter defibrillator shock/antitachycardia therapy, since no class III antiarrhythmic agents have proven survival benefit. The risks discussed mainly focus on pro-arrhythmia as torsade de pointes ventricular tachycardia.
Collapse
Affiliation(s)
- Hanne Elming
- Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
| | | | | | | | | | | |
Collapse
|
28
|
Guo H, Shaheen W, Kerber R, Olshansky B. Cardioversion of atrial tachyarrhythmias: anticoagulation to reduce thromboembolic complications. Prog Cardiovasc Dis 2004; 46:487-505. [PMID: 15224256 DOI: 10.1016/j.pcad.2003.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
29
|
Hongo RH, Themistoclakis S, Raviele A, Bonso A, Rossillo A, Glatter KA, Yang Y, Scheinman MM. Use of ibutilide in cardioversion of patients with atrial fibrillation or atrial flutter treated with class IC agents. J Am Coll Cardiol 2004; 44:864-8. [PMID: 15312873 DOI: 10.1016/j.jacc.2004.05.051] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Revised: 05/05/2004] [Accepted: 05/11/2004] [Indexed: 11/19/2022]
Abstract
OBJECTIVES We sought to assess the efficacy and safety of ibutilide cardioversion for those with atrial fibrillation (AF) or atrial flutter (AFL) receiving long-term treatmentwith class IC agents. BACKGROUND Attenuation of ibutilide-induced QT prolongation has been observed in a small number of patients pretreated with class IC agents. The clinical significance of the interaction between ibutilide and class IC agents is unknown. METHODS Seventy-one patients with AF (n = 48) or AFL (n = 23), receiving propafenone 300 to 900 mg/day (n = 46) or flecainide 100 to 300 mg/day (n = 25), presented for ibutilide (2.0 mg) cardioversion. RESULTS The mean durations of arrhythmia episode and arrhythmia history were 25 +/- 48 days and 4.4 +/- 6.4 years, respectively. Sixty-five patients (91.5%) had normal left ventricular systolic function. Twenty-three of 48 patients (47.9%; 95% confidence interval, 33.3% to 62.8%) with AF and 17 of 23 patients (73.9%; 95% confidence interval, 51.6% to 89.8%) with AFL converted with mean conversion times of 25 +/- 14 min and 20 +/- 12 min, respectively. There was a small increase in corrected QT interval after ibutilide (from442 +/- 61 ms to 462 +/- 59 ms, p = 0.006). One patient developed non-sustained polymorphous ventricular tachycardia and responded to intravenous magnesium. Another developed sustained torsade de pointes and was treated effectively with direct-current shock and intravenous dopamine. CONCLUSIONS Our observations suggest that the use of ibutilide in patients receiving class IC agents is as successful in restoring sinus rhythm and has a similar incidence of adverse effects as the use of ibutilide alone.
Collapse
|
30
|
Abstract
Safe and effective control of rapid ventricular rates in acute-onset atrial fibrillation (AF) can be accomplished with intravenous calcium antagonists, beta-blockers or amiodarone; digoxin is less effective. If pharmacologic cardioversion of AF is desired, single oral doses of propafenone or flecainide are safe and effective in patients without structural heart disease. Intravenous ibulitide is moderately effective in the conversion of persistent AF or atrial flutter, with a small risk of proarrhythmia. In wide QRS complex tachycardia of uncertain origin, adenosine and lidocaine are no longer recommended. Procainamide or amiodarone are the treatment options, but attempts should be made to define the origin of tachycardia. In the treatment of monomorphic ventricular tachycardia, lidocaine is no longer recommended; procainamide or amiodarone are the recommended therapies. In polymorphic ventricular tachycardia with a normal QT interval, beta-blockers are recommended. In shock-refractory ventricular fibrillation, lidocaine, and magnesium are ineffective; intravenous amiodarone should be the treatment of choice.
Collapse
Affiliation(s)
- Andrea Sarkozy
- Division of Cardiology, St. Michael's Hospital, 30 Bond Street, 7-050Q, Toronto, Ontario M5B 1W8, Canada.
| | | |
Collapse
|
31
|
Santini M, Pignalberi C, Ricci R, Calò L, Santini L. Effectiveness of ibutilide in cardioversion of persistent atrial fibrillation in patients with dual chamber stimulation. J Interv Card Electrophysiol 2003; 9:15-20. [PMID: 12975565 DOI: 10.1023/a:1025360202173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIM OF THE STUDY To evaluate the effectiveness of Ibutilide in cardioversion of persistent atrial fibrillation in patients with sinus node disease wearing a dual chamber pacemaker and to assess the potential role of overdrive ventricular pacing in prevention of drug related proarrhythmia. METHODS AND RESULTS Fifty-three sinus node disease patients (35 males; mean age 75 +/- 9.5 years), implanted with a dual chamber pacing system, with persistent atrial fibrillation, lasting for 328 +/- 416 days, received 1-2 mg of intravenous Ibutilide. Pacing mode was programmed in VVI at 90 ppm, in order to suppress spontaneous ventricular activity. All patients were monitored for 4 hours. Late occurrence of ventricular arrhythmias was evaluated using the pacemaker memory. Ventricular pacing threshold, spontaneous electrogram amplitude and pacing impedance were measured before and after Ibutilide infusion. Cardioversion to sinus rhythm occurred in twenty-two patients (41.5%). Treatment success was significantly related to shorter atrial fibrillation duration. Paced QT interval duration increased from 412 +/- 36 ms to 481 +/- 40 ms (p < 0.0001), without differences between responders and non responders; QRS width did not change significantly (from 152 +/- 25 ms to 161 +/- 25 ms; p = n.s.). No early or late episodes of sustained or non sustained polymorphic ventricular tachycardia were observed. Pacing and sensing threshold did not show any significant variation. CONCLUSIONS Ibutilide showed a good effectiveness in treating persistent atrial fibrillation in paced patients. Overdrive ventricular pacing may have played a role in preventing drug induced ventricular proarrhythmia. No adverse effect on pacing threshold was observed.
Collapse
Affiliation(s)
- Massimo Santini
- Department of Cardiology, S. Filippo Neri Hospital, via Martinotti 20, 00135 Rome, Italy.
| | | | | | | | | |
Collapse
|
32
|
Gowda RM, Punukollu G, Khan IA, Wilbur SL, Vasavada BC, Sacchi TJ. Ibutilide for pharmacological cardioversion of atrial fibrillation and flutter: impact of race on efficacy and safety. Am J Ther 2003; 10:259-63. [PMID: 12845389 DOI: 10.1097/00045391-200307000-00005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the racial differences in the efficacy and safety of ibutilide in patients with recent-onset (<2 weeks) atrial fibrillation and atrial flutter. METHODS This study included 58 consecutive patients with recent-onset atrial fibrillation (n = 34) and atrial flutter (n = 24). The mean age was 65.7 +/- 14.6 years (range, 37-86 years), 47% were women (n = 27) and 34% (n = 20) were African Americans. The duration of arrhythmia ranged from 3 hours to 2 weeks. All patients had echocardiography, were on therapeutic anticoagulation, had a fairly well controlled ventricular rate, normal QTc interval on 12-lead electrocardiography, and normal serum electrolytes. Ibutilide was administered as an intravenous infusion with a maximal dose of 2 mg. RESULTS The overall conversion rate to sinus rhythm was 66% (n = 38), with 62% (n = 21) with atrial fibrillation and 71% (n = 17) of atrial flutter. Most conversions (84%) occurred within 45 minutes of ibutilide infusion. The mean time to arrhythmia conversion was 37.4 +/- 59.8 minutes. Race had a significant impact on efficacy, with increased conversions seen in African Americans (P = 0.004) and increased nonconversion seen in whites (P = 0.02). Successful conversion was not affected by the left atrial size or the presence of valvular heart disease, hypertension, heart failure, coronary heart disease, and diabetes mellitus. QTc intervals were prolonged after drug administration, with a mean change of 24.6 milliseconds for all patients. The QTc prolongation after drug administration was greater in African Americans than in whites (27.4 vs. 23.3 milliseconds). Torsade de pointes occurred in 4 patients (3 African Americans) and was treated with intravenous magnesium sulfate and electrical cardioversion. CONCLUSION Ibutilide used for pharmacological cardioversion of atrial fibrillation and atrial flutter is more effective in African Americans but carries a higher risk of torsade de pointes.
Collapse
Affiliation(s)
- Ramesh M Gowda
- Division of Cardiology, Long Island College Hospital, Brooklyn, New York, USA
| | | | | | | | | | | |
Collapse
|
33
|
Kanoupakis EM, Kochiadakis GE, Manios EG, Igoumenidis NE, Mavrakis HE, Vardas PE. Pharmacological cardioversion of recent onset atrial fibrillation with intravenous amiodarone in patients receiving long-term amiodarone therapy: is it reasonable? J Interv Card Electrophysiol 2003; 8:19-26. [PMID: 12652173 DOI: 10.1023/a:1022367311529] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In clinical practice the use of intravenous amiodarone has been proposed for the conversion of recurrent atrial fibrillation in patients already under chronic treatment with the same drug. Given that intravenous amiodarone exhibits different electrophysiological properties than when the drug is taken orally over a long period, this approach seems reasonable, but its effectiveness and safety have not been investigated systematically before. Of 45 patients under chronic treatment with amiodarone for the maintenance of sinus rhythm who had atrial fibrillation of recent onset, 23 were given intravenous loading of the same drug for 24 hours and 22 received placebo. Nine patients underwent an electrophysiological study several months after the successful restoration of sinus rhythm, before and after another intravenous loading dose of amiodarone, in order to examine the possible electrophysiological changes. In the amiodarone group 20 patients were successfully converted to sinus rhythm, compared to 13 of the placebo group (p < 0.05). No serious side effects of the intravenous administration were observed. Prolongation of refractoriness was seen in all 9 patients who underwent electrophysiological study after intravenous loading, without any effect on repolarization, atrioventricular conduction or sinus node function. In conclusion an intravenous loading dose of amiodarone exerts an additional electrophysiological effect in patients already under chronic treatment with the same drug. Such a combined therapy could be used with a high efficacy and safety for the conversion of recent onset atrial fibrillation in patients who are receiving long-term amiodarone therapy.
Collapse
|
34
|
Abstract
Atrial fibrillation is the most common arrhythmia in the United States, whose incidence is greatest in the elderly population. This rhythm disorder can be paroxysmal or chronic and is associated with a range of clinical conditions from palpitations and dyspnea to stroke and death. In the elderly the mainstay of treatment of atrial fibrillation should utilize drug therapy. The main goals of drug therapy should be effective rate control to avoid tachycardia-induced cardiomyopathy, anticoagulation to reduce the risk of stroke and thromboembolism, and maintenance of sinus rhythm to prevent adverse atrial remodeling. In those patients in whom effective rate control cannot be achieved, catheter ablation of the atrioventricular node and implantation of a permanent pacemaker should be considered. Catheter ablation of atrial fibrillation by targeting pulmonary venous foci or pulmonary venous isolation currently remains investigational and we advocate its use be limited to symptomatic patients who have failed traditional therapy.
Collapse
Affiliation(s)
- Anil Yadav
- Department of Medicine, Division of Cardiology, Cardiac Electrophysiology Section, University of California at San Francisco, San Francisco, CA 94143, USA.
| | | |
Collapse
|
35
|
Oral H, Ozaydin M, Tada H, Chugh A, Hassan S, Scharf C, Lai SWK, Greenstein R, Pelosi F, Knight BP, Strickberger SA, Morady F. Comparison of amiodarone versus ibutilide for the prevention of immediate recurrences of atrial fibrillation during pulmonary vein isolation. Am J Cardiol 2002; 90:492-5. [PMID: 12208408 DOI: 10.1016/s0002-9149(02)02520-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
During segmental ostial ablation for pulmonary vein isolation, pulmonary vein potentials are easily identified during sinus rhythm or left atrial pacing. Therefore, maintenance of atrial fibrillation (AF) during the procedure is desirable. However, cardioversion is occasionally followed by an immediate recurrence of AF. This study compared the efficacy of ibutilide and amiodarone in preventing immediate recurrences of AF in patients who underwent pulmonary vein isolation. The subjects of this study were 25 patients (mean age 56 +/- 10 years) who underwent pulmonary vein isolation for AF who had an immediate recurrence of AF within 60 seconds after 2 transthoracic cardioversions. The patients were randomized to receive an infusion of either 300 mg of amiodarone over 10 minutes or 1 mg of ibutilide over 5 minutes. Cardioversion was repeated 15 minutes after the drug infusion. If immediate recurrences of AF occurred 2 more times, the alternative study drug was administered, and cardioversion was repeated. Immediate recurrences of AF were suppressed by amiodarone in 8 of 10 patients (80%), and by ibutilide in 9 of 15 patients (60%, p = 0.4). After crossover, immediate recurrence of AF was suppressed in 2 of 6 patients (33%) by amiodarone, and in 1 of 2 patients (50%) by ibutilide (p = 0.6). Ibutilide and amiodarone, when used alone or in combination, prevented immediate recurrences of AF in 20 of 25 patients (80%). There were no adverse drug effects. Ibutilide and amiodarone were equally effective in suppressing immediate recurrences of AF. Overall, immediate recurrences of AF can be prevented by amiodarone and/or ibutilide in 80% of patients.
Collapse
Affiliation(s)
- Hakan Oral
- Division of Cardiology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Sticherling C, Ozaydin M, Tada H, Oral H, Pelosi F, Knight BP, Strickberger SA, Morady F. Comparison of verapamil and ibutilide for the suppression of immediate recurrences of atrial fibrillation after transthoracic cardioversion. J Cardiovasc Pharmacol Ther 2002; 7:155-60. [PMID: 12232564 DOI: 10.1177/107424840200700305] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Verapamil and ibutilide blunt the atrial fibrillation-induced shortening of atrial refractoriness that may predispose to an immediate recurrence of atrial fibrillation after cardioversion. This study compared the efficacy of verapamil and ibutilide in preventing an immediate recurrence of atrial fibrillation. METHODS AND RESULTS Transthoracic cardioversion was performed in 223 patients with atrial fibrillation. Atrial fibrillation recurred within 10 minutes after cardioversion on two occasions in 21 patients (9.4%). Twenty of these patients were randomly assigned to receive an infusion of either 0.15 mg/kg of verapamil at a rate of 2 mg/min (11 patients), or 1 mg of ibutilide over 10 minutes (9 patients). Eight patients (73%) had another episode of immediate recurrence of atrial fibrillation after verapamil, compared to two patients (22%) after ibutilide (P<0.05). Including the results after crossover, immediate recurrence of atrial fibrillation occurred in 8 of 12 patients (67%) who received verapamil, compared to 3 of 16 patients (19%) who received ibutilide (P=0.02). Verapamil and/or ibutilide successfully prevented immediate recurrence of atrial fibrillation in 17 of 20 patients (85%). After 700 days of follow-up, there was no significant difference in the recurrence rate of atrial fibrillation between the patients in whom immediate recurrence of atrial fibrillation was prevented by verapamil and/or ibutilide and the patients who were successfully converted to sinus rhythm and did not have immediate recurrence of atrial fibrillation. CONCLUSIONS Ibutilide is more effective than verapamil in preventing immediate recurrence of atrial fibrillation. Suppression of immediate recurrence of atrial fibrillation by ibutilide and/or verapamil may allow for long-term maintenance of sinus rhythm postcardioversion as often as in patients who do not experience immediate recurrence of atrial fibrillation.
Collapse
Affiliation(s)
- Christian Sticherling
- Division of Cardiology, Department of Internal Medicine, University Hospital Benjamin Franklin, Free University of Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Slavik RS, Tisdale JE, Borzak S. Pharmacologic conversion of atrial fibrillation: a systematic review of available evidence. Prog Cardiovasc Dis 2001; 44:121-52. [PMID: 11568824 DOI: 10.1053/pcad.2001.26966] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report reviews the efficacy of currently available antiarrhythmic agents for conversion of atrial fibrilation (AF) to normal sinus rhythm (NSR). A systematic search of literature in the English language was done on computerized databases, such as MEDLINE, EMBASE, and Current Contents, in reference lists, by manual searching, and in contact with expert informants. Published studies involving humans that described the use of antiarrhythmic therapy for conversion of AF to NSR were considered and only studies that examined the use of agents currently available in the United States were included. Studies exclusively describing antiarrhythmic therapy for conversion of postsurgical AF were excluded. The methodology and results of each trial were assessed and attempts were made to acquire additional information from investigators when needed. Assessment of methodological quality was incorporated into a levels-of-evidence scheme. Eighty-eight trials were included, of which 34 (39%) included a placebo group (level I data). We found in recent-onset AF of less than 7 days, intravenous (i.v.) procainamide, high-dose i.v. or high-dose combination i.v. and oral amiodarone, oral quinidine, oral flecainide, oral propafenone, and high-dose oral amiodarone are more effective than placebo for converting AF to NSR. In recent-onset AF of less than 90 days, i.v. ibutilide is more effective than placebo and i.v. procainamide. In chronic AF, oral dofetilide converts AF to NSR within 72 hours, and oral propafenone and amiodarone are effective after 30 days of therapy. We conclude than for conversion of recent-onset AF of less than 7 days, procainamide may be considered a preferred i.v. agent and propafenone a preferred oral agent. For conversion of recent-onset AF of longer duration (less than 90 days), i.v. ibutilide may be considered a preferred agent. For patients with chronic AF and left ventricular dysfunction, direct current cardioversion is the preferred conversion method. Larger, well-designed randomized controlled trials with clinically important endpoints in specific populations of AF patients are needed.
Collapse
Affiliation(s)
- R S Slavik
- Clinical Services Unit-Pharmaceutical Sciences, Vancouver Hospital and Health Sciences Center, University of British Columbia, Vancouver, BC, Canada
| | | | | |
Collapse
|
38
|
Abstract
The decline in the use of sodium channel blockers has led to an expanding use of b-blockers and complex class III agents such as sotalol and amiodarone for controlling cardiac arrhythmias. Success with these agents in the context of their side effects has spurred the development of compounds with simpler ion channel-blocking properties with less complex adverse reactions. The resulting so-called pure class III agents were found to have antifibrillatory effects in atrial fibrillation (AF) and flutter, as well as in ventricular tachyarrhythmias. Pure class III compounds are effective in inducing acute chemical conversion of AF, in preventing paroxysmal AF, and in maintaining sinus rhythm in patients with persistent AF restored to sinus rhythm. Examples of such compounds are dofetilide, which selectively blocks IKr, and ibutilide, available only as an intravenous agent, which blocks the IKr and augments the inactivated Na+ current in atrial myocytes. Dofetilide and ibutilide have been introduced into clinical practice. Azimilide is the first of the class III agents that blocks both components (IKr and IKs) of the delayed rectifier current, which may confer certain electrophysiologic advantages. The potential therapeutic niche of ibutilide, dofetilide, and azimilide in the control of cardiac arrhythmias forms the basis of this review.
Collapse
Affiliation(s)
- B N Singh
- Division of Cardiology 111E, VA Medical Center of West Los Angeles, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA.
| | | |
Collapse
|