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Abstract
The amount of literature on amiodarone pulmonary toxicity (APT) peaked in 1983-1984 with several hundred cases reported cumulatively, and declined thereafter. Since the mid-1990s, publications have increased, which suggests that APT remains a current problem in clinical practice. Amiodarone remains difficult to diagnose noninvasively, and although the outcome is good in the majority of patients, not all cases of APT can be controlled satisfactorily.
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Affiliation(s)
- Philippe Camus
- Department of Pulmonary Medicine and Critical Care, Centre Hospitalier et Université de Bourgogne, F-2100 Dijon, France.
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2
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Maury P, Zimmermann M, Metzger J, Reynard C, Dorsaz P, Adamec R. Amiodarone therapy for sustained ventricular tachycardia after myocardial infarction: long-term follow-up, risk assessment and predictive value of programmed ventricular stimulation. Int J Cardiol 2000; 76:199-210. [PMID: 11104875 DOI: 10.1016/s0167-5273(00)00379-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We determine the value of the programmed ventricular stimulation (PVS) and of clinical, angiographic and electrophysiologic variables in assessing the long-term risk of arrhythmia recurrence in a group of coronary artery diseased patients presenting with a first episode of monomorphic sustained ventricular tachycardia (VT) treated with amiodarone. Mortality and arrhythmia recurrence rates were retrospectively assessed in 55 consecutive patients with previous myocardial infarction presenting with a first VT episode. Results of left heart catheterization, echocardiography and time-domain signal-averaging were collected. Patients underwent PVS after amiodarone oral loading and were classified according to inducibility before being all discharged on amiodarone (200 mg daily). The mean follow-up was 42+/-31 months. Total and cardiac mortality rates were 29% (16 patients) and 23% (13 patients) respectively. Sudden death (SD) occurred in nine patients (16%). VT recurred in 13 patients (23%). Sustained monomorphic VT was inducible in 40 patients (72%) after amiodarone loading. Neither total mortality (10/40 vs. 6/15) nor cardiac mortality (3/40 vs. 1/15) were significantly different between inducible and non-inducible patients. Recurrent VT rate was 27% (11/40 patients) for the inducible group and 13% (2/15 patients) for the non-inducible group (NS). SD occurred in 6/40 inducible patients (15%) and in 2/15 non-inducible patients (13%) (NS). Arrhythmic events occurred in 42% (17/40) inducible patients vs. 26% (4/15) non-inducible patients (P=0.07). Parameters correlated with outcome were ejection fraction (EF) (5 SD/11 patients with EF <0.3 vs. 4/44 with EF >0.3, P=0.003), mitral insufficiency (MI) (4 SD/10 patients with MI vs. 4/44 patients without MI, P=0.004) and age (65+/-9 years for patients with VT recurrence vs. 58+/-9, P=0.02). Although the risk stratification can be improved, reliable and safe long-term prediction of recurrence of malignant ventricular arrhythmia in individual patients cannot be made. Consequently, the systematic implantation of a cardioverter-defibrillator in case of a first episode of sustained VT occurring in coronary artery disease patients should be further debated.
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Affiliation(s)
- P Maury
- Division of Cardiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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3
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Abstract
This article provides a review of the risks faced by patients with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) in the absence of a reversible or transient cause so that the goals of therapy can be clearly defined. The therapeutic approaches that have been proposed to achieve these goals are outlined and evidence comparing these various approaches to therapy is then summarized in order to propose an algorithm for the optimal use of antiarrhythmic drug therapies as primary therapy for selected VT/VF patients. Options for the ancillary uses of antiarrhythmic drug therapies in ICD patients are considered.
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Affiliation(s)
- L B Mitchell
- Division of Cardiology, University of Calgary, Alberta, Canada
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4
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Calkins H, Bigger JT, Ackerman SJ, Duff SB, Wilber D, Kerr RA, Bar-Din M, Beusterien KM, Strauss MJ. Cost-effectiveness of catheter ablation in patients with ventricular tachycardia. Circulation 2000; 101:280-8. [PMID: 10645924 DOI: 10.1161/01.cir.101.3.280] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND This study evaluated the cost-effectiveness of catheter ablation therapy versus amiodarone for treating ventricular tachycardia (VT) in patients with structural heart disease. The analysis used a societal perspective for a hypothetical cohort of VT patients with implantable cardioverter-defibrillators, who were experiencing frequent shocks. METHODS AND RESULTS We calculated incremental cost-effectiveness of ablation relative to amiodarone over 5 years after treatment initiation. Event probabilities were from the Chilli randomized clinical trial (Chilli Cooled Ablation System, Cardiac Pathways Corporation, Sunnyvale, Calif), the literature, and a consensus panel. Costs were from 1998 national Medicare reimbursement schedules. Quality-of-life weights (utilities) were estimated using an established preference measurement technique. In a hypothetical cohort of 10 000 patients, 5-year costs were higher for patients undergoing ablation compared with amiodarone therapy ($21 795 versus $19 075). Ablation also produced a greater increase in quality of life (2.78 versus 2.65 quality-adjusted life-years [QALYs]). This yielded a cost-effectiveness ratio of $20 923 per QALY gained for ablation compared with amiodarone. Results were relatively insensitive to assumptions about ablation success and durability. In less severe patients with good ejection fractions who suffer their first VT episode, the incremental cost-effectiveness ratio was $6028 per QALY gained. These cost-effectiveness ratios are within the range generally thought to warrant technology adoption. CONCLUSIONS This study demonstrates that, from a societal perspective, catheter ablation appears to be a cost-effective alternative to amiodarone for treating VT patients.
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Affiliation(s)
- H Calkins
- Johns Hopkins University, Baltimore, MD, USA.
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5
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MITCHELL LBRENT. Pharmacological Therapy for Ventricular Arrhythmias in the Era of the Implantable Cardioverter Defibrillator: Indispensable or Inadvisable? J Interv Cardiol 1998. [DOI: 10.1111/j.1540-8183.1998.tb00124.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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6
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Mitchell LB, Sheldon RS, Gillis AM, Connolly SJ, Duff HJ, Gardner MJ, Hui WK, Ramadan D, Wyse DG. Definition of predicted effective antiarrhythmic drug therapy for ventricular tachyarrhythmias by the electrophysiologic study approach: randomized comparison of patient response criteria. J Am Coll Cardiol 1997; 30:1346-53. [PMID: 9350938 DOI: 10.1016/s0735-1097(97)00294-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES We sought to compare efficacies of therapy for ventricular tachyarrhythmias selected by programmed stimulation using two different patient response efficacy criteria: <5 versus <16 repetitive ventricular responses. BACKGROUND Therapy selection for ventricular tachyarrhythmias by programmed stimulation requires definition of a patient response that predicts long-term efficacy. Such definitions have not been previously compared prospectively. METHODS Patients with sustained ventricular tachyarrhythmias were randomized to therapy selection using either the <5 or <16 repetitive response criterion of predicted effective therapy. The primary end point was sudden death or recurrence of ventricular tachyarrhythmia requiring intervention. RESULTS Predicted effective drug therapy was found for 23 (34%) of 68 patients randomized to the <5 criterion and 29 (36%) of 81 patients randomized to the <16 criterion (p = NS). Definition of therapy required 3.0 +/- 1.6 drug trials (mean +/- SD) in patients randomized to the <5 criterion and 2.9 +/- 1.8 trials in patients randomized to the <16 criterion (p = NS). Patients randomized to the <5 criterion had a lower 2-year probability of the primary end point (0.20 +/- 0.05) than did patients randomized to the <16 criterion (0.33 +/- 0.05, one-tailed p = 0.004). The advantage of the <5 criterion was also seen in subgroup analyses involving patients with and without an initial drug efficacy prediction. CONCLUSIONS The programmed stimulation approach to the selection of antiarrhythmic therapy for ventricular tachyarrhythmias using a patient response criterion of <5 repetitive ventricular responses results in a lower probability of recurrence of ventricular tachyarrhythmia than does use of a <16 repetitive response criterion.
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Affiliation(s)
- L B Mitchell
- Department of Medicine, Foothills Hospital and University of Calgary, Alberta, Canada
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7
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Guindo J, Genis AB, Dominguez de Rozas JM, Fiol M, Vinolas X, Bay�s de Luna A. Sudden death in heart failure. Heart Fail Rev 1997. [DOI: 10.1007/bf00127406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Nasir N, Swarna US, Boahene KA, Doyle TK, Pacifico A. Therapy of Sustained Ventricular Arrhythmias With Amiodarone: Prediction of Efficacy With Serial Electrophysiologic Studies. J Cardiovasc Pharmacol Ther 1996; 1:123-132. [PMID: 10684409 DOI: 10.1177/107424849600100206] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Programmed electrical stimulation early during amiodarone therapy has poor prognostic capabilities; and persistent inducibility has been associated with a favorable outcome in a majority of patients. These observations result from studies that differed significantly in methodology. METHODS AND RESULTS: The authors prospectively enrolled 121 patients in a standardized amiodarone dosing protocol in which amiodarone was the only antiarrhythmic agent. Electrophysiologic testing was done after 2 and 6 weeks to determine noninducibility, predictive value, and the significance of drug-induced prolongation of tachycardia cycle length. The mean age of the patients in the study was 63.2 +/- 11.5 years, and their ejection fraction was 32.8 +/- 11.9%. Coronary artery disease was present in 103 (85%). At 2 weeks 17 patients (14%) were no longer inducible, whereas 104 patients (86%) remained inducible. Patients in these groups were similar in age and ejection fraction. During follow-up evaluation, recurrences (35% vs 24%; P =.44) and sudden death (12% vs 13.5%) were similar in the two groups. Thirty-five of 95 patients (32%) with sustained monomorphic ventricular tachycardia had more than 100 ms prolongation of their cycle length, which was hemodynamically well tolerated (partial response), but 60 did not (nonresponse). Patients with a partial response were older (66.5 vs 61.1 years; P =.02) and had longer QRS durations (143.2 vs 129.4 ms; P =.03). They also had increased recurrences (37% vs 17%; P =.01) and more sudden deaths (23% vs 8%; P =.02). At 6 weeks 11 of 76 patients studied were noninducible. They had a lower recurrence rate than those who remained inducible (8% vs 27%; P =.02) but a similar number of sudden deaths (8% vs 16%; P =.27). Thirty-two patients partially responded, and 31 patients did not respond. During follow-up examination these two groups had a similar number of recurrences (25% vs 29%; P =.76) and sudden deaths (16% vs 16%). CONCLUSIONS: Noninducibility at 2 or 6 weeks of amiodarone therapy did not identify patients at low risk of sudden death. In inducible patients, tachycardia cycle length prolongation, even when well tolerated, was not a marker for favorable outcome. Electrophysiologically guided therapy, therefore, offers little benefit over empiric amiodarone.
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Affiliation(s)
- N Nasir
- The Texas Arrhythmia Institute, Houston, Texas, USA
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9
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Abstract
The article has summarized the studies and ongoing trials looking at the significance and treatment of ventricular tachyarrhythmias. In most instances, the presence of these arrhythmias is associated with an increased risk of future arrhythmic events. Electrophysiologic studies are helpful in risk stratification in patients with coronary artery disease but can be misleading in the setting of dilated cardiomyopathy and often produce nonspecific results in patients with HCM. The need for an invasive electrophysiologic study is crucial in the diagnosis of certain ventricular arrhythmias that are amenable to cure with radiofrequency catheter ablation, such as idiopathic ventricular tachycardia and BBR-VT. The correct approach for patients with SVT not amenable to catheter ablation remains to be determined. In deciding whether to use a device or drug therapy, however, one should take into consideration the degree of left ventricular dysfunction and the overall health status of the patient. For example, device implantation clearly reduces sudden death in patients with severe left ventricular dysfunction but may not change total mortality because these same patients may die of congestive heart failure. Device therapy might be more cost-effective for patients with less severe depression of left ventricular function.
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Affiliation(s)
- M Hamdan
- Electrophysiology Division, University of California, San Francisco, USA
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10
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Martínez-Rubio A, Shenasa M, Chen X, Wichter T, Breithardt G, Borggrefe M. Response to sotalol predicts the response to amiodarone during serial drug testing in patients with sustained ventricular tachycardia and coronary artery disease. Am J Cardiol 1994; 73:357-60. [PMID: 7509121 DOI: 10.1016/0002-9149(94)90008-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
UNLABELLED It was analyzed whether the response to sotalol can predict the response to amiodarone as evaluated by programmed ventricular stimulation in 30 patients with coronary artery disease and documented recurrent sustained ventricular tachycardia (VT). Programmed ventricular stimulation was performed using 1 or 2 extrastimuli during sinus rhythm and 4 drive cycle lengths at 2 right ventricular sites. If no ventricular tachyarrhythmia was induced, a third extrastimulus was introduced during a paced cycle length of 500 ms. During the control study, VT (mean cycle length 305 +/- 63 ms) was induced in all patients, and the right ventricular effective refractory period (during S1-S1 = 500 ms) was 223 +/- 12 ms. After sotalol, sustained and nonsustained VT were inducible in 22 (73%) and 7 (23%) patients, respectively. One patient did not undergo stimulation on sotalol, because of side effects. After amiodarone, sustained and nonsustained VT were inducible in 23 (77%) and 7 (23%) patients, respectively. The mean cycle length of the induced VT was prolonged after both drugs by 17% (p < 0.001). The effective refractory period was prolonged by 15% (p < 0.001) after sotalol and by 13% (p < 0.001 compared with baseline study; p = NS between both drugs) after amiodarone. Thus, concordant results (effective or ineffective drug) between sotalol and amiodarone were found in 26 patients (87%). IN CONCLUSION (1) The effects of sotalol and amiodarone on the cycle length of induced VT and on right ventricular effective refractory period were similar; and (2) inability to suppress VT by amiodarone can be predicted from the response to sotalol.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Martínez-Rubio
- Department of Cardiology and Angiology, University of Münster, Germany
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11
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Abstract
Demonstrated associations between postmyocardial infarction ventricular arrhythmias and a higher subsequent risk of both sudden and all-cause mortality have prompted a search for effective and safe treatment modalities. Recently completed clinical trials have provided a rationale for treatment recommendations in some specific settings. Beta-blocking therapy is recommended for postinfarction patients with frequent or complex ventricular premature beats. In contrast, calcium antagonist therapy is not helpful in these cases, and Class I antiarrhythmic therapy is actually harmful. Early indications of benefit from Class III antiarrhythmic therapies, particularly amiodarone, are under evaluation in large trials. Patients with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) occurring late after myocardial infarction require therapy. Viable therapeutic methods include individualized antiarrhythmic therapy selected by the noninvasive approach, individualized antiarrhythmic therapy selected by the invasive approach, empiric amiodarone therapy, transcatheter or surgical ablative therapy (for VT), and use of an implantable cardioverter defibrillator. Clinical trial data have yet to determine which of these approaches is most effective under which circumstances. Postinfarction patients with nonsustained VT are the focus of several ongoing treatment trials. Early data suggest that risks requiring specific therapy are reached only by those patients who also have significant left ventricular dysfunction. The presence of inducible sustained ventricular tachycardia at an electrophysiologic study may further risk stratify such patients. High-risk patients with nonsustained ventricular tachycardia, left ventricular dysfunction, and inducible sustained ventricular tachycardia should participate in ongoing clinical trials. In the absence of this opportunity, intensive treatment should be considered.
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Affiliation(s)
- L B Mitchell
- Foothills Hospital, University of Calgary, Alberta, Canada
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12
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Anastasiou-Nana MI, Nanas JN, Nanas SN, Rapti A, Poyadjis A, Stathaki S, Moulopoulos SD. Effects of amiodarone on refractory ventricular fibrillation in acute myocardial infarction: experimental study. J Am Coll Cardiol 1994; 23:253-8. [PMID: 8277089 DOI: 10.1016/0735-1097(94)90528-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the efficacy of a single dose of intravenous amiodarone in facilitating defibrillation of ventricular fibrillation refractory to lidocaine and epinephrine plus direct current countershocks in experimental acute myocardial infarction. BACKGROUND Amiodarone has been hailed as the most effective single antiarrhythmic drug for the treatment of ventricular arrhythmias. However, intravenous amiodarone has only sporadically been used in the defibrillation of ventricular fibrillation in acute myocardial infarction. METHODS Acute myocardial infarction was induced in 60 dogs by ligation of the proximal left anterior descending coronary artery for 2 h. Animals that developed spontaneous ventricular fibrillation were treated with lidocaine and epinephrine plus five direct-current countershocks. Dogs with ventricular fibrillation refractory to this regimen were randomized to further treatment with additional intravenous administration of epinephrine and bolus lidocaine plus < or = 15 direct-current countershocks (group I) or administration of amiodarone, 10 mg/kg body weight intravenously, followed by defibrillation with direct-current counter-shock (group II). RESULTS Sixteen (27%) of the 60 dogs in which the protocol was attempted developed spontaneous ventricular fibrillation 21 min after ligation and were included in the study. Lidocaine and epinephrine plus five direct-current countershocks succeeded in converting ventricular fibrillation in one dog (6%). The other 15 dogs were randomized to group I (8 dogs) or group II (7 dogs). Defibrillation was achieved in one of the eight dogs in group I and in six of the seven dogs in group II (p < 0.005). CONCLUSIONS In an experimental model of acute ischemia, intravenous amiodarone (10 mg/kg) influences positively the response to defibrillation of ventricular fibrillation refractory to lidocaine and epinephrine plus direct current countershocks.
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Affiliation(s)
- M I Anastasiou-Nana
- Department of Clinical Therapeutics, University of Athens School of Medicine, Alexandra Hospital, Greece
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13
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Ector H, Rogers R, Rubens A, De Geest H. Classification of death in patients under antiarrhythmic treatment. Pacing Clin Electrophysiol 1993; 16:2250-4. [PMID: 7508602 DOI: 10.1111/j.1540-8159.1993.tb02331.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In the evaluation of antiarrhythmic treatment, total mortality and total cardiac mortality are the only endpoints difficult to misclassify. End-stage cardiac failure competes with "suddenness" in many instances of sudden arrhythmic death. This observational study reports on 23 deaths in a group of 129 patients under antiarrhythmic treatment. In the 21 cases of cardiac death, with respect to the notion "sudden arrhythmic death," classification was problematic in 6 patients. According to different interpretations, the number of deaths listed as "sudden" could vary between one and six. A concise description of cause and circumstances of death, is presented.
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Affiliation(s)
- H Ector
- Department of Cardiology, University Hospital Gasthuisberg, Leuven, Belgium
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14
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Sager PT, Nademanee K, Antimisiaris M, Pacifico A, Pruitt C, Godfrey R, Singh BN. Antiarrhythmic effects of selective prolongation of refractoriness. Electrophysiologic actions of sematilide HCl in humans. Circulation 1993; 88:1072-82. [PMID: 8353869 DOI: 10.1161/01.cir.88.3.1072] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Recent data have suggested that antiarrhythmic agents that act largely by delaying conduction may not be as effective in controlling ventricular arrhythmias as those that prolong repolarization. Recently, numerous "pure" class III agents have been developed. METHODS AND RESULTS The antiarrhythmic and electrophysiologic profiles of sematilide, a "pure" class III agent, were determined in 27 patients with clinical ventricular arrhythmias and inducible sustained ventricular tachycardia during electrophysiologic study. After treatment with oral sematilide (mean dose, 133 +/- 29 mg every 8 hours), the patients underwent repeat 24-hour ambulatory ECG monitoring and electrophysiologic study. The baseline sinus cycle length and QT, QTc, JT, and JTc intervals were significantly increased 8 to 17% by sematilide (P = .001 to .029). There were no changes in the PR or QRS intervals. Sematilide (at a paced cycle length of 600 ms) significantly increased the atrial effective refractory period (238 +/- 32 to 264 +/- 32 ms; 11 +/- 16% increase from baseline; P = .013), atrioventricular nodal effective refractory period (296 +/- 74 to 354 +/- 71 ms; 20 +/- 19%; P = .029), and right ventricular effective refractory period (252 +/- 25 to 281 +/- 30 ms; 12 +/- 8%; P < .001) but did not significantly change the PA or HV intervals, the corrected sinus node recovery time, or the Wenckebach cycle length. Determination of the frequency-dependent effects of sematilide (n = 10) on the right ventricular monophasic action potential duration (APD90) during ventricular pacing at cycle lengths of 600 to 300 ms revealed that the APD90 was significantly prolonged by sematilide during ventricular pacing at 600 to 350 ms (APD90 increase of 40 +/- 17, 27 +/- 21, 18 +/- 18, and 14 +/- 15 ms, respectively) but not at 300 ms (APD increase of 13 +/- 19 ms). Sematilide significantly prolonged the APD90 to a greater degree at longer than at shorter cycle lengths (P = .02). The ventricular effective refractory period had a similar reverse frequency-dependent relation as the APD90. Sematilide had no effect on the ventricular effective refractory period-to-APD90 ratio or on ventricular conduction. Sematilide suppressed the induction of sustained ventricular tachycardia in 41% of all patients exposed to sematilide. Prolongation of ventricular refractoriness was correlated with ventricular tachycardia suppression. The right ventricular effective refractory period (at 600 ms) increased by 38 +/- 14 ms in patients whose sustained ventricular tachycardia was suppressed by sematilide and by 19 +/- 18 ms in patients not suppressed (P = .015). One patient developed short runs of pause-dependent nonsustained ventricular tachycardia. Eight patients were placed on long-term sematilide therapy, and during a mean follow-up period of 7.0 +/- 7.5 months, two patients developed sudden cardiac death, and one additional patient had recurrent sustained ventricular tachycardia. CONCLUSIONS The electrophysiologic profile of sematilide is consistent with selective block of outward potassium currents and associated isolated lengthening of the ventricular effective refractory period and APD; sematilide demonstrates a significant degree of reverse frequency-dependence of the ventricular APD and effective refractory period; and suppression of ventricular tachycardia inducibility by sematilide appears to be correlated with increases in the right ventricular effective refractory period.
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Affiliation(s)
- P T Sager
- Division of Cardiology, Veterans Affairs Medical Center of West Los Angeles, CA 90073
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15
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Proclemer A, Facchin D, Vanuzzo D, Feruglio GA. Risk stratification and prognosis of patients treated with amiodarone for malignant ventricular tachyarrhythmias after myocardial infarction. Cardiovasc Drugs Ther 1993; 7:683-9. [PMID: 8241012 DOI: 10.1007/bf00877822] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Seventy-seven consecutive patients (mean age 62 years) with episodes of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) after acute myocardial infarction (AMI) were evaluated to assess the long-term efficacy of first-line amiodarone treatment and to identify clinical and laboratory factors associated with a high risk of death or arrhythmia recurrence. The presenting arrhythmia was VT in 41 cases (53%) and VF in 36 (47%). VT or VF occurred between the 4th and 90th day after AMI in 45 cases (58%) and later (more than 90 days) in the remaining 32 (42%). The mean number of arrhythmic episodes was 4.2. Forty patients (52%) were in New York Heart Association (NYHA) class I or II, and 37 (48%) were in class III or IV. Mean left ventricular ejection fraction was 32%; ventricular aneurysm was present in 41 subjects. Most patients had multivessel coronary artery disease. Amiodarone was administered as a first-choice drug in all patients, in combination with other antiarrhythmic drugs in 14. By ventricular stimulation after loading doses of amiodarone, sustained VT was inducible in 46 (62%) and noninducible in 28 (38%). During a mean follow-up of 28 months the incidence of cardiac mortality at 1, 3, and 5 years was 21%, 37%, and 47%; of sudden death was 7%, 19%, and 23%; of nonfatal VT recurrence was 13%, 13%, and 24%, respectively. The overall incidence of amiodarone side effects was 35%.2+ was a weak predictor only by univariate analysis (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Proclemer
- Istituto di Cardiologia, Ospedale S.M. della Misericordia, Udine, Italy
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16
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Olson PJ, Woelfel A, Simpson RJ, Foster JR. Stratification of sudden death risk in patients receiving long-term amiodarone treatment for sustained ventricular tachycardia or ventricular fibrillation. Am J Cardiol 1993; 71:823-6. [PMID: 8456761 DOI: 10.1016/0002-9149(93)90831-v] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
One hundred twenty-two patients treated chronically with amiodarone for sustained ventricular tachycardia or ventricular fibrillation after failing conventional antiarrhythmic therapy were analyzed to determine which factors were predictive of sudden cardiac death during follow-up. The mean left ventricular ejection fraction in the study group was 0.32, and 87% of the patients had coronary artery disease with a prior myocardial infarction. During a median follow-up of 19.5 months, 30 patients died suddenly. The only variable that was predictive of sudden death was left ventricular ejection fraction. Twenty-nine of the 84 patients with ejection fractions < 0.40 died suddenly, compared with 1 of 35 patients with ejection fractions > or = 0.40. The actuarial probability of sudden death at 5 years was 49% when the ejection fraction was < 0.40, and 5% when the ejection fraction was > or = 0.40 (p = 0.0004). These results indicate that patients treated with amiodarone for sustained ventricular tachycardia or ventricular fibrillation whose ejection fractions are > or = 0.40 are at low risk for sudden death. Patients with ejection fractions < 0.40 remain at high risk for sudden death, and should be considered for additional or alternative therapy.
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Affiliation(s)
- P J Olson
- Division of Cardiology, University of North Carolina School of Medicine, Chapel Hill
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Weinberg BA, Miles WM, Klein LS, Bolander JE, Dusman RE, Stanton MS, Heger JJ, Langefeld C, Zipes DP. Five-year follow-up of 589 patients treated with amiodarone. Am Heart J 1993; 125:109-20. [PMID: 8417505 DOI: 10.1016/0002-8703(93)90063-f] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Between 1977 and 1986, 589 patients (age, 57 +/- 13 years; 464 men and 125 women) received amiodarone for ventricular fibrillation (VF; 147 patients), sustained (VT-S; 242 patients) or nonsustained (VT-NS; 80 patients) ventricular tachycardia, or supraventricular tachycardia (SVT; 120 patients). Mean left ventricular ejection fraction was 36 +/- 17%, with 23% in New York Heart Association functional class I, 49% in class II, 25% in class III, and 3% in class IV. Sixty-two percent had ischemic heart disease. Follow-up was 32 +/- 27 months (mean +/- SD). Life table analysis revealed that patients with VF, VT-S, and VT-NS had a cumulative incidence of sudden death of 9% at 1 year, increasing by about 3% per year. By years 2 and 5, the cumulative incidence of sudden death, VF, or VT-S recurrence was 26% and 38% and the percent of patients still taking amiodarone was 54% and 32%. For patients with SVT at years 2 and 5, the cumulative incidence of sudden death was 1% and 3%, and of sudden death or SVT recurrence the cumulative incidence was 20% and 29%. The percent of patients still taking amiodarone was 67% and 43%. Of 14 clinical variables assessed, New York Heart Association functional class was the best predictor of sudden death and arrhythmic failure and no other variable added independent predictive power. Older age and lower left ventricular ejection fraction were independent predictors of drug failure (sudden death or arrhythmic failure or need to discontinue amiodarone because of side effects). We conclude that despite its side effect profile, amiodarone is an effective and reasonably well-tolerated antiarrhythmic drug.
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Affiliation(s)
- B A Weinberg
- Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis 46202-4800
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18
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O'Brien BJ, Buxton MJ, Rushby JA. Cost effectiveness of the implantable cardioverter defibrillator: a preliminary analysis. BRITISH HEART JOURNAL 1992; 68:241-5. [PMID: 1389748 PMCID: PMC1025025 DOI: 10.1136/hrt.68.8.241] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND An implantable cardioverter defibrillator (ICD) may be effective in reducing the risk of sudden cardiac death. The high cost of ICD treatment, however, compared with alternatives raises the question of whether this new technology is an efficient use of scarce health care resources. OBJECTIVE To estimate the incremental cost effectiveness of the implantable cardioverter defibrillator compared with drug treatment with amiodarone in the management of patients at high risk of sudden cardiac death. DESIGN A cost effectiveness model was constructed from data already published and other secondary sources. Differences in patient survival were calculated from life tables for comparable ICD and amiodarone patient series. Costs were based on typical patient management protocols derived from current United Kingdom practice and interviews with physicians. MAIN OUTCOME MEASURES Cost effectiveness of ICD treatment was computed over 20 years; all future costs and effects were discounted at 6% per year. RESULTS Estimated life expectancy was 11.1 and 6.7 years with ICD and amiodarone respectively; the discounted 20 year difference lies in the range 1.7 to 3.7 years. Discounted 20 year treatment costs were 28,400 pounds for the ICD and 2300 pounds for amiodarone. Cost effectiveness of ICD treatment lies in the range of 15,400 pounds to 8200 pounds per life-year gained. CONCLUSIONS Cost effectiveness of ICD treatment is similar to some existing cardiac programmes funded under the NHS but uncertainty exists due to limitations of the data. Costs of ICD treatment may fall in the future as the life of the device increases and less invasive implantation methods are needed. The effectivess of ICD compared with amiodarone is currently being studied by a randomised controlled trial.
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Affiliation(s)
- B J O'Brien
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
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19
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NATTEL STANLEY, TALAJIC MARIO, FERMINI BERNARD, ROY DENIS. Amiodarone: Pharmacology, Clinical Actions, and Relationships Between Them. J Cardiovasc Electrophysiol 1992. [DOI: 10.1111/j.1540-8167.1992.tb00972.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Abstract
The possible effect of amiodarone administration on the effectiveness and complications of electrical cardioversion of supraventricular tachyarrhythmias has not been properly assessed. To investigate the effects of amiodarone on cardioversion, we performed 130 electrical cardioversion procedures in 116 patients who were receiving long-term amiodarone therapy (group I) and 44 cardioversion procedures in 43 patients who were receiving intravenous infusions of amiodarone (group II). All patients in groups I and II had atrial fibrillation or flutter. In group I, there was a higher incidence of ventricular premature beats than in a control group of patients who underwent 100 cardioversions; one patient had severe bradycardia with asystole, which was resolved satisfactorily. In group II there was a higher incidence of sinus bradycardia and ventricular premature beats. It was concluded that electrical cardioversion of supraventricular arrhythmias can be safely performed in patients who are receiving long-term oral or intravenous amiodarone therapy if the usual precautions are observed.
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Affiliation(s)
- J Sagristà-Sauleda
- Servicio de Cardiologia, Hospital General Universitari Vall d'Hebron, Barcelona, Spain
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21
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Gill J, Heel RC, Fitton A. Amiodarone. An overview of its pharmacological properties, and review of its therapeutic use in cardiac arrhythmias. Drugs 1992; 43:69-110. [PMID: 1372862 DOI: 10.2165/00003495-199243010-00007] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Amiodarone, originally developed over 20 years ago, is a potent antiarrhythmic drug with the actions of all antiarrhythmic drug classes. It has been successfully used in the treatment of symptomatic and life-threatening ventricular arrhythmias and symptomatic supraventricular arrhythmias. In patients with left ventricular dysfunction amiodarone does not usually produce any clinically significant cardiodepression and the drug has relatively high antiarrhythmic efficacy. Preliminary studies indicate that amiodarone may have a beneficial effect on mortality and survival in certain groups of patients with ventricular arrhythmias, an action probably related to both its antiarrhythmic and antifibrillatory effects. The adverse effect profile of amiodarone is diverse, involving the cardiac, thyroid, pulmonary, hepatic, gastrointestinal, ocular, neurological and dermatological systems. Interstitial pneumonitis and hepatitis are potentially fatal, but the vast majority of adverse events are less serious, and some may be dose dependent. Pretreatment monitoring, regular assessments and the use of minimum effective doses are, therefore, necessary. Thus, with appropriate monitoring to control its well recognised adverse effects amiodarone has an important place as an effective 'broad spectrum' antiarrhythmic drug which has, so far, been used when other treatments have proved ineffective. More recent preliminary data also suggest that it may also have a beneficial effect in the prevention of sudden death in some patients.
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Affiliation(s)
- J Gill
- Adis International Limited, Chester, UK
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22
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Evans SJ, Myers M, Zaher C, Simonson J, Nalos P, Vaughn C, Oseran D, Gang E, Peter T, Mandel W. High dose oral amiodarone loading: electrophysiologic effects and clinical tolerance. J Am Coll Cardiol 1992; 19:169-73. [PMID: 1729329 DOI: 10.1016/0735-1097(92)90069-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Although amiodarone is an effective drug for the treatment of life-threatening ventricular arrhythmias, no standard oral loading dose protocol has been defined, and patients often undergo prolonged hospitalization for amiodarone loading. High dose (greater than 1,800 mg/day) oral loading has usually been reserved for unstable patients with incessant ventricular tachyarrhythmias. The current study was designed to 1) examine the clinical and electrophysiologic effects of a high dose oral amiodarone loading regimen in more stable patients; and 2) ascertain its safety and tolerance, possibly allowing shortened amiodarone loading periods and potentially decreased length of hospital stay. The study group included 16 patients with a history of recurrent ventricular arrhythmias and decreased left ventricular function, who were refractory to prior antiarrhythmic drug therapy. The oral loading protocol was 50 mg/kg per day of amiodarone for 3 days, then 30 mg/kg per day for 2 days, followed by maintenance therapy of 300 to 400 mg twice daily. Electrophysiologic testing was performed at baseline, on days 1 and 5 and during week 6. Amiodarone and desethylamiodarone levels were measured and symptoms monitored. Clinically, the high dose loading protocol was well tolerated in 15 of the 16 patients. Arrhythmias were rendered noninducible by day 1 in three patients and remained noninducible throughout the study period in two of the three. The remaining patients continued to have inducible ventricular tachycardia. Ventricular tachycardia cycle length and right ventricular effective refractory period both progressively increased significantly over baseline, starting on day 1. The 15 patients who remained in the study had no significant side effects during the loading period.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S J Evans
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles 90048
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23
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24
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Abstract
The antiarrhythmic properties of amiodarone at the ventricular level were discovered in the early 1970s. The unanimously recognised efficacy of amiodarone includes a weak negative inotropic effect and compensatory vasodilatory properties, making amiodarone particularly suitable for treating the potentially malignant arrhythmias associated with organic disease. In a review of 611 hospitalised patients on amiodarone, and 353 patients in whom the drug had been prescribed, over a 52-month period in our 60-bed department, we noted that amiodarone was prescribed in 53% of patients for arrhythmias and in 47% of patients for coronary insufficiency. Ventricular arrhythmias represented 13% of the rhythmic indications. These indications differ from those in the USA. The efficacy (70 to 90%) of amiodarone in ventricular extrasystoles has been shown in open studies. In coronary patients, the antiarrhythmic activity of amiodarone is superior to that of propranolol. However, there has been no controlled study because the need for a loading dosage, and the electrocardiographic effects render such studies difficult. After myocardial infarction, ventricular arrhythmias constitute a significant risk factor independently of prognosis; amiodarone may be useful in this indication, and studies of the European Myocardial Infarction Amiodarone Trial (EMIAT) type will examine its value here. Since 1973, it has been recognised that amiodarone can prevent ventricular tachycardia in 55 to 89% of patients in the clinical situation. After a long-standing controversy, the positive predictive value of programmed stimulation has finally been agreed on. In hypertrophic cardiomyopathy, retrospective studies suggest a reduction in mortality in patients treated with amiodarone. By contrast, the value of amiodarone in dilated cardiomyopathy requires more intensive investigation. We consider amiodarone to be indicated in ventricular arrhythmic complexes, particularly if they are associated with an ejection fraction of less than 35% and/or atrial fibrillation. The value of amiodarone in arrhythmias associated with heart failure needs to be evaluated. In conclusion, amiodarone is a powerful antiarrhythmic agent but, because of the possibility of dose- and duration-dependent side effects, evaluation of the risk: benefit ratio in each indication is needed.
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Affiliation(s)
- S Levy
- Department of Cardiology, Hôpital Nord, University of Aix, Marseille, France
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Peter CT, Helfant RH. Postinfarction ventricular tachycardia and fibrillation: reassessing the role of drug therapy and approach to the high risk patient. J Am Coll Cardiol 1990; 16:531-2. [PMID: 2387925 DOI: 10.1016/0735-1097(90)90337-o] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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