Side effects from amiodarone

Long-Term Outcomes of Pulmonary Vein Isolation in Patients With Brugada Syndrome and Paroxysmal Atrial Fibrillation

Background Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BrS) is challenging. In addition, patients with BrS with an implantable cardioverter-defibrillator (ICD) might experience inappropriate shocks for fast AF. Long-term outcome of pulmonary vein isolation in BrS has not been well established yet, and it is still unclear whether pulmonary vein triggers are the only pathophysiological mechanism of AF in BrS. The aim of the study is to assess the long-term outcomes in patients with BrS undergoing pulmonary vein isolation for paroxysmal AF compared with a matched cohort of patients without BrS. Methods and Results Sixty patients with BrS undergoing pulmonary vein isolation with cryoballoon catheter ablation for paroxysmal AF were matched with 60 patients without BrS, who underwent the same procedure. After a mean follow-up of 58.2±31.7 months, freedom from atrial tachyarrhythmias was achieved in 61.7% in the BrS group and in 78.3% in the non-BrS group (log-rank P=0.047). In particular, freedom from AF was 76.7% in the first group and in 83.3% in the second (P=0.27), while freedom from atrial tachycardia/atrial flutter was 85% and 95% (P=0.057). In the BrS group, 29 patients (48.3%) had an ICD and 8 (27.6%) had a previous ICD-inappropriate shock for fast AF. In the BrS cohort, ICD-inappropriate interventions for AF were significantly reduced after ablation (3.4% versus 27.6%; P=0.01). Conclusions Pulmonary vein isolation in patients with BrS was associated with higher rate of arrhythmic recurrence. Despite this, catheter ablation significantly reduced inappropriate ICD interventions in BrS patients and can be considered a therapeutic strategy to prevent inappropriate device therapies.

Clinical management of electrical storm: a current overview

The number of patients affected by electrical storm has been continuously increasing in emergency departments. Patients are often affected by multiple comorbidities requiring multidisciplinary interventions to achieve a clinical stability. Careful reprogramming of cardiac devices, correction of electrolyte imbalance, knowledge of underlying heart disease and antiarrhythmic drugs in the acute phase play a crucial role. The aim of this review is to provide a comprehensive overview of pharmacological treatment, latest transcatheter ablation techniques and advanced management of patients with electrical storm.

Altered Mental Status and Hyponatremia After 20 Hours of Amiodarone Therapy

A 66-year-old woman with no relevant medical history presented at the emergency department with new-onset atrial fibrillation. We initiated intravenous amiodarone therapy. At 20 hours, the patient experienced severe neurologic symptoms, hyponatremia, and syndrome of inappropriate antidiuretic hormone. We discontinued amiodarone, infused saline solution, and restricted the patient's fluid intake. She recovered in 3 days. This case illustrates that amiodarone-induced syndrome of inappropriate antidiuretic hormone with hyponatremia can occur far earlier than expected during acute amiodarone therapy.

Imaging drugs, metabolites and biomarkers in rodent lung: a DESI MS strategy for the evaluation of drug-induced lipidosis

Within drug development and pre-clinical trials, a common, significant and poorly understood event is the development of drug-induced lipidosis in tissues and cells. In this manuscript, we describe a mass spectrometry imaging strategy, involving repeated analysis of tissue sections by DESI MS, in positive and negative polarities, using MS and MS/MS modes. We present results of the detected distributions of the administered drug, drug metabolites, lipid molecules and a putative marker of lipidosis, di-docosahexaenoyl (22:6)-bis(monoacylglycerol) phosphate (di-22:6-BMP). A range of strategies have previously been reported for detection, isolation and identification of this compound, which is an isomer of di-docosahexaenoic (22:6 n-3) phosphatidylglycerol (di-22:6 PG), a commonly found lipid that acts as a surfactant in lung tissues. We show that MS imaging using MS/MS can be used to differentiate these compounds of identical mass, based upon the different distributions of abundant fragment ions. Registration of images of these fragments, and detected drugs and metabolites, is presented as a new method for studying drug-induced lipidosis in tissues. Graphical abstract.

Amiodarone use and the risk of acute pancreatitis: Influence of different exposure definitions

Purpose

The antiarrhythmic drug amiodarone has a long half‐life of 60 days, which is often ignored in observational studies. This study aimed to investigate the impact of different exposure definitions on the association between amiodarone use and the risk of acute pancreatitis.

Method

Using data from the Dutch PHARMO Database Network, incident amiodarone users were compared to incident users of a different type of antiarrhythmic drug. Eighteen different definitions were applied to define amiodarone exposure, including dichotomized, continuous and categorized cumulative definitions with lagged effects to account for the half‐life of amiodarone. For each exposure definition, a Cox proportional hazards model was used to estimate the hazard ratio (HR) of hospitalization for acute pancreatitis.

Results

This study included 15,378 starters of amiodarone and 21,394 starters of other antiarrhythmic drugs. Adjusted HRs for acute pancreatitis ranged between 1.21−1.43 for dichotomized definitions of exposure to amiodarone, between 1.13‐1.22 for dose definitions (per DDD) and between 0.52‐1.72 for cumulative dose definitions, depending on the category. Accounting for lagged effects had little impact on estimated HRs.

Conclusions

This study demonstrates the relative insensitivity of the association between amiodarone and the risk of acute pancreatitis against a broad range of different exposure definitions. Accounting for possible lagged effects had little impact, possibly because treatment switching and discontinuation was uncommon in this population.

Maternal monitoring and safety considerations during antiarrhythmic treatment for fetal supraventricular tachycardia

Fetal tachycardia is a rare complication during pregnancy. After exclusion of maternal and fetal conditions that can result in a secondary fetal tachycardia, supraventricular tachycardia is the most common cause of a primary sustained fetal tachyarrhythmia. In cases of sustained fetal supraventricular tachycardia, maternal administration of digoxin, flecainide, sotalol, and more rarely amiodarone, is considered. As these medications have the potential to cause significant adverse effects, we sought to examine maternal safety during transplacental treatment of fetal supraventricular tachycardia. In this narrative review we summarize the literature addressing pharmacologic properties, monitoring, and adverse reactions associated with medications most commonly prescribed for transplacental therapy of fetal supraventricular tachycardia. We also describe maternal monitoring practices and adverse events currently reported in the literature. In light of our findings, we provide clinicians with a suggested maternal monitoring protocol aimed at optimizing safety.

Amiodarone's major metabolite, desethylamiodarone, induces apoptosis in human cervical cancer cells

Previously, we found that desethylamiodarone (DEA) may have therapeutic potentiality in bladder cancer. In this study, we determined its effects on human cervical cancer cells (HeLa). Cell viability was evaluated by Muse Cell Count & Viability Assay; cell apoptosis was detected by Muse Annexin V & Dead Cell Assay. Cell cycle was flow cytometrically determined by Muse Cell Cycle Kit and the morphological changes of the cells were observed under a fluorescence microscope after Hoechst 33342 staining. The changes in the expression levels of apoptosis-related proteins in the HeLa cells were assessed by immunoblot. Our results showed that DEA significantly inhibited the proliferation and viability of HeLa cells and induced apoptosis in vitro in dose-dependent and also in cell cycle-dependent manner because DEA induced G0/G1 phase arrest in the HeLa cell line. We found that DEA treatment downregulated the expression of phospho-Akt and phospho-Bad. In addition, DEA could downregulate expression of Bcl-2, upregulate Bax, and induce cytochrome c release. Our results indicate that DEA might have significance as an anti-tumor agent against human cervical cancer.

Rapid onset of amiodarone induced pulmonary toxicity after lung lobe resection - A case report and review of recent literature

Amiodarone-induced pulmonary toxicity (APT) is a severe side effect that can lead to lung fibrosis or fatal respiratory failure. Usually APT occurs during long term therapy after administration of prolonged loading doses or high cumulative doses. We present the case of a 58 year old woman who underwent thoracic surgery with lobe resection. She developed atrial fibrillation with hemodynamic-instability on the first post-operative day. We initiated amiodarone therapy and four days later she developed respiratory failure. The pulmonary function further deteriorated showing signs of an acute respiratory distress syndrome (ARDS). We therefore started mechanical ventilation, but still the gas exchange did not improve. A computer tomography-(CT)-scan presented bilateral interstitial and alveolar infiltrations. The patient also presented with leukocytosis, elevated C-reactive protein (CRP) levels however without elevated procalcitonin (PCT) concentrations. In the tracheal secretion we only harvested foam cells, but got no evidence for pathogens causing pneumonia. We immediately started glucocorticoid therapy with prednisolone 50 mg/d for five days. Almost instantaneously the gas exchange ameliorated. We were able to wean the patient from the respirator within five days. Pulmonary infiltrations were nearly vanished in a CT-scan few days later and completely disappeared in follow up examinations. This case demonstrates a per-acute onset of APT caused by a low loading dose in association with thoracic surgery. The initiation of glucocorticoid therapy in parallel to amiodarone withdrawal led to full recovery of the patient. One should consider APT when signs of pulmonary failure occur during brief periods of amiodarone therapy especially after thoracic surgery.

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Amiodarone-induced pulmonary toxicity (APT) can develop after low dose and short term amiodarone therapy.

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The early generation of APT is supported by thoracic surgery.

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APT can cause severe adult respiratory distress syndrome, leading to respiratory failure.

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Glucocorticoid therapy ameliorates APT symptoms and can restore respiratory failure in early state.

Amiodarone-induced pulmonary toxicity--a fatal case report and literature review

Amiodarone is a widely used and very potent antiarrhythmic substance. Among its adverse effects, pulmonary toxicity is the most dangerous without a causal treatment option. Due to a very long half-life, accumulation can only be prevented by strict adherence to certain dosage patterns. In this review, we outline different safe and proven dosing schemes of amiodarone and compare the incidence and description of pulmonary toxicity. Reason for this is a case of fatal pulmonary toxicity due to a subacute iatrogenic overdosing of amiodarone in a 74-year-old male patient with known severe coronary artery disease, congestive heart failure and ectopic atrial tachycardia with reduced function of kidneys and liver but without preexisting lung disease. Within 30 days, the patient received 32.2 g of amiodarone instead of 15.6 g as planned. Despite early corticosteroid treatment after fast exclusion of all other differential diagnoses, the patient died another month later in our intensive care unit from respiratory failure due to bipulmonal pneumonitis.

Syndrome of inappropriate antidiuretic hormone in association with amiodarone therapy: a case report and review of literature

BACKGROUND

Amiodarone is a class III antiarrhythmic agent that is widely used in the treatment of a variety of arrhythmias. Several different systemic side effects are reported after use of this medication. In this article, we report a case that had developed syndrome of inappropriate antidiuretic hormone (SIADH) after starting treatment with this agent.

CASE REPORT

The patient is a 66-year-old male with past medical history of hypertension, hyperlipidemia, coronary artery disease, and class III New York Heart Association congestive heart failure who presented with monomorphic nonsustained ventricular tachycardia. A loading dose of amiodarone followed by maintenance dose was started. Baseline serum sodium of 138 mmol/L on admission decreased to 119 mmol/L by day 7, and a diagnosis of SIADH was made. The patient was not taking any other medication known to cause SIADH, nor had any such comorbidity to explain it. Serum sodium increased to 133 and 138 mmol/L, respectively, after 16 and 33 days from discontinuation of amiodarone.

CONCLUSION

SIADH is a rare but serious side effect of amiodarone and practicing physicians should be aware of this complication, particularly after loading dose of the medication.

Rationale and design of a randomized clinical trial comparing stress reduction treatment to usual cardiac care: the Reducing Vulnerability to Implantable Cardioverter Defibrillator Shock-Treated Ventricular Arrhythmias (RISTA) trial

OBJECTIVE

To present the design of a multicenter, randomized trial testing the effects of stress reduction treatment (SRT) on the prevalence of shock-treated ventricular arrhythmias among patients with an implantable cardioverter defibrillator (ICD). Significant adjustment problems secondary to ICD shock can increase the likelihood of arrhythmias requiring shock for termination. Whether SRT can reduce arrhythmias requiring shock for termination in patients with ICDs has not been tested in clinical trials.

METHODS

New ICD recipients and previous recipients who have received an appropriate therapeutic shock in the last 6 months (n = 304) will be enrolled and randomized to either SRT or usual cardiac care. Participants complete a psychosocial questionnaire and undergo laboratory mental stress testing and 24-hour Holter monitoring with diary at study entry and approximately 4 months later. Follow-ups are completed at 6, 12, and 24 months post randomization to assess occurrence of ICD shock for ventricular arrhythmias (primary outcome), antitachycardia pacing events, medication changes, hospitalizations, deaths, and quality of life.

RESULTS

Log-rank test and Cox proportional hazards model will be used to test the effects of SRT on time to first shock-treated ventricular arrhythmia, with exploratory analyses testing the effects on overall frequency of ventricular arrhythmia. Secondary analyses will test the effects of SRT on laboratory stress-induced and 24-hour arrhythmogenic electrophysiological indices from pre to post treatment, and both quality of life and measures of anger across the 2 years of the study.

CONCLUSIONS

The Reducing Vulnerability to ICD Shock-Treated Ventricular Arrhythmias (RISTA) Trial is the first large-scale, randomized, clinical trial designed to evaluate the effect of SRT on the prevalence of shock-treated arrhythmias among patients with an ICD. Results may demonstrate a treatment that can reduce vulnerability to arrhythmia-provoked shock and improve quality of life.

Long-term low-dose amiodarone therapy in the management of ventricular and supraventricular tachyarrhythmias: efficacy and safety

BACKGROUND

Amiodarone hydrochloride has been in use for two decades for the control of ventricular and supraventricular arrhythmias. Established and emerging evidence indicates that amiodarone has an antiarrhythmic efficacy superior to that of most other drugs.

HYPOTHESIS

The study was undertaken to evaluate the efficacy and acceptability of low-dose amiodarone therapy in the long-term management of supraventricular and ventricular tachyarrhythmias.

METHODS

A total of 124 patients with symptomatic drug-refractory or life-threatening arrhythmias managed with low-dose oral amiodarone therapy over a 10-year period was analyzed retrospectively. Of these, 45 patients (36%) had ventricular arrhythmias, 52 (42%) had atrial arrhythmias, and 27 (22%) had atrioventricular reentry tachycardia. Loading doses of amiodarone 600 mg daily for 1 week were administered for supraventricular arrhythmias and 600-1200 mg daily for 2 weeks for ventricular arrhythmias. Maintenance daily doses were 194 +/- 48 and 206 +/- 55 mg, respectively. Mean treatment duration was 32 +/- 28 months, with 326.3 patient years of therapy.

RESULTS

Of 39 patients with sustained ventricular tachyarrhythmias, the actuarial incidence of satisfactory arrhythmia control (absence of sudden cardiac death or nonfatal arrhythmia recurrence) was 78% at 1 year and 71% at 2 years. Satisfactory control of supraventricular arrhythmias (mean ventricular rate < 100/min with significant symptomatic improvement for sustained atrial arrhythmias and < 1 attack per year for paroxysmal atrial or atrioventricular arrhythmias) was achieved in 73, 65, and 62% of patients at 1, 2, and 3 years, respectively. The cumulative incidence of amiodarone-related adverse effects was 5.8 per 100 patient years, with drug withdrawal required in 12 patients (9.7%). Fifteen patients had thyroid dysfunction, 2 had hepatic toxicity, and 1 developed nonfatal pulmonary fibrosis. Overall, the incidence of successful use of amiodarone (satisfactory arrhythmia control and freedom from side effects) was 67, 59, and 53% at 1, 2, and 3 years, respectively.

CONCLUSIONS

The results of this study suggest that the efficacy of low-dose amiodarone therapy in the management of serious ventricular and supraventricular arrhythmias would be similar to those achieved with higher doses, but with a much more acceptable side effect profile.

Effects of amiodarone on lung tissue mechanics and parenchyma remodeling

We studied the results of chronic oral administration of amiodarone on in vitro lung tissue mechanics, light and electron microscopy. Fifteen Wistar male rats were divided into three groups. In control (CTRL) group animals received saline (0.5 mL/day). In amiodarone (AMIO) groups, amiodarone was administered by gavage at a dose of 175 mg/kg 5 days per week for 6 (6AMIO) or 12 weeks (12AMIO). Lung tissue strips were analyzed 24h after the last drug administration. Tissue resistance and elastance were higher in 6AMIO and 12AMIO than in CTRL, while hysteresivity was similar in all groups. Total amount of collagen fibers in lung parenchyma increased progressively with the time course of the lesion. However, at 6 weeks there was an increase in the amount of type III collagen fibers, while in 12AMIO mainly type I collagen fibers were found. In our study amiodarone increased lung tissue impedance that was accompanied by matrix remodeling and lesion of type II pneumocytes.

Hyperglobulinemia in Amiodarone-induced Pneumonitis

BACKGROUND

Amiodarone is a very effective antiarrhytmic drug. However its use may be accompanied by side effects. Hyperglobulinemia was not described in association with amiodarone treatment.

MATERIALS AND METHODS

Fifteen patients, who developed hyperglobulinemia while on amiodarone therapy, were identified among the patients hospitalized in our hospital. Serum globulin concentration was measured prior to, during and after amiodarone therapy.

RESULTS

In 11 of the 15 patients with amiodarone-associated hyperglobulinemia, amiodarone treatment had to be stopped because of amiodarone-induced complications, nine of them had pneumonitis. Mean serum globulin level rose during amiodarone therapy from 2.48 +/- 0.51 g/dL to 4.11 +/- 0.71 g/dL (p = 0.001), and declined after it was stopped to 2.80 +/- 0.49 g/dL (p = 0.001). In 50 patients treated by amiodarone, serum globulin was similar to that found in 50 patients with ischemic heart disease not treated by amiodarone [2.64 +/- 0.39 g/dL and 2.56 +/- 0.29 g/dL respectively (p = 0.21)].

CONCLUSIONS

In some patients amiodarone therapy may be associated with hyperglobulinemia. The incidence of this association is not known. Most of the patients with amiodarone-associated hyperglobulinemia have amiodarone-induced toxicity, mainly pneumonitis. Amiodarone therapy does not cause a general increase in serum globulins. Hyperglobulinemia may be a marker for a damaged organ, or it may have a pathogenetic role in the induction of pneumonitis.

Combination of minimally invasive thyroid surgery and local anesthesia associated to iopanoic acid for patients with amiodarone-induced thyrotoxicosis and severe cardiac disorders: a pilot study

BACKGROUND AND AIMS

Amiodarone-induced thyrotoxicosis is a life-threatening condition. A prompt control of thyrotoxicosis is obtained by thyroidectomy. Preparation with iopanoic acid proved to be very effective in reducing cardiovascular complications. Nevertheless, general anesthesia and extensive surgery may affect negatively patients also after adequate preparation. Safety and efficacy of minimally invasive video-assisted thyroidectomy performed under regional anesthesia (bilateral modified deep cervical block) in patients with amiodarone-induced thyrotoxicosis was evaluated.

PATIENTS AND METHODS

Eight patients with amiodarone-induced thyrotoxicosis (three with type I and five with type II), mean age 66.2 years, were prepared with iopanoic acid. There were five men and three women. Three patients had dilatative cardiomyopathy, three had heart failure secondary to severe myocardial infarction, and two had refractory unstable rhythm disorders.

RESULTS

Minimally invasive video-assisted thyroidectomy was performed under regional anesthesia. Mean operative time was 55.5 min. During surgery, lung and heart function remained well and no surgical complications occurred. After surgery, all patients remained on amiodarone therapy and two patients were subsequently removed from the checklist for heart transplantation.

CONCLUSION

Minimally invasive video-assisted thyroidectomy under regional anesthesia can be proposed as resolution of amiodarone-induced thyrotoxicosis in high risk patients with severe cardiac disorders, after preparation with iopanoic acid.

Cost-effectiveness of radiofrequency catheter ablation for atrial fibrillation

OBJECTIVES

We sought to compare the cost-effectiveness of left atrial catheter ablation (LACA), amiodarone, and rate control therapy in the management of atrial fibrillation (AF).

BACKGROUND

Left atrial catheter ablation has been performed to eliminate AF, but its cost-effectiveness is unknown.

METHODS

We developed a decision-analytic model to evaluate the cost-effectiveness of LACA in 55- and 65-year-old cohorts with AF at moderate and low stroke risk. Costs, health utilities, and transition probabilities were derived from published literature and Medicare data. We performed primary threshold analyses to determine the minimum level of LACA efficacy and stroke risk reduction needed to make LACA cost-effective at 50,000 dollars and 100,000 dollars per quality-adjusted life-year (QALY) thresholds.

RESULTS

In 65-year-old subjects with AF at moderate stroke risk, relative reduction in stroke risk with an 80% LACA efficacy rate for sinus rhythm restoration would need to be > or =42% and > or =11% to yield incremental cost-effectiveness ratios (ICERs) <50,000 dollars and 100,000 dollars per QALY, respectively. Higher and lower LACA efficacy rates would require correspondingly lower and higher stroke risk reduction for equivalent ICER thresholds. In the 55-year-old moderate stroke risk cohort, lower LACA efficacy rates or stroke risk reduction would be needed for the same ICER thresholds. In patients at low stroke risk, LACA was unlikely to be cost-effective.

CONCLUSIONS

The use of LACA may be cost-effective in patients with AF at moderate risk for stroke, but it is not cost-effective in low-risk patients. Our threshold analyses may provide a framework for the design of future clinical trials by providing effect size estimates for LACA efficacy needed.

Pro-arrhythmic effects of amiodarone and concomitant rate-control medication

AIMS

Amiodarone is one of the most efficient and safe antiarrhythmic drugs in the treatment of atrial fibrillation (AF). Although pro-arrhythmic effects of amiodarone therapy are rare, the aim of the present study was to identify clinical constellations which may lead to amiodarone-associated pro-arrhythmia.

METHODS AND RESULTS

Sixty-three consecutive patients (pts) (49 males; 64+/-10.3 years; 35 with coronary heart disease, 17 with lone AF) were retrospectively included in this study. All received an oral (92.1%) or i.v. (7.9%) loading dose of amiodarone for the treatment of AF. Cardiac diseases, concomitant medical treatment, and incidence of pro-arrhythmic effects were analysed. Three pts (4.8% of the total population) developed a clinical relevant, polymorphic ventricular tachyarrhythmia, 3-48 h after initiation of amiodarone loading. Coronary heart disease was present in all of these pts, and in two of them left ventricular ejection fraction was severely reduced. The mean QTc in these pts was only slightly prolonged; mean heart rate was significantly decreased compared with the total study population (61.0+/-7.5 vs. 74.5+/-24.1 bpm; P < or = 0.05). In all pts with pro-arrhythmia, amiodarone (two pts i.v., one patient oral) was initiated during concomitant beta-blocker/digitalis therapy. Twenty-five per cent of the patients receiving this 'triple' therapy developed ventricular arrhythmia.

CONCLUSION

The present study implies that initiation of amiodarone therapy in pts with structural heart disease and AF that are concomitantly treated with beta-blockers and digitalis may have an increased risk of amiodarone-associated pro-arrhythmia.

A randomized trial of prophylactic antiarrhythmic agents (amiodarone and sotalol) in patients with atrial fibrillation for whom direct current cardioversion is planned

Antiarrhythmic agents enhance maintenance of sinus rhythm (SR) after direct current cardioversion (DCC) for atrial fibrillation but there are few comparative trials.

BACKGROUND

The aims of the study were (1) to establish whether patients successfully cardioverted to SR are more likely to stay in SR over 6 months if taking amiodarone or sotalol, and if so, to establish whether one agent is better than the other; (2) to establish whether taking amiodarone or sotalol is better at achieving chemical cardioversion within the 6 weeks before DCC; and (3) to establish whether DCC is more likely to be successful on a drug.

METHODS

Randomized, prospective, nonblinded, controlled study of treatment with either amiodarone (n = 27), sotalol (n = 36), or no antiarrhythmic agent (n = 31).

RESULTS

Chemical cardioversion occurred in 7 patients in the amiodarone group (A), 7 patients in the sotalol group (S), but none in the no-antiarrhythmic group (N). A total of 33 (92%) patients in the sotalol group, 22 (81%) patients in the amiodarone group, and 23 (74%) patients in the no-antiarrhythmic group were in SR after cardioversion. Of the original cohort of patients, 17 (63%) patients in the amiodarone group remained in SR at 6-month follow-up, compared with 14 (39%) in the sotalol group and 5 (16%) in the no-antiarrhythmic group (A vs N, P < .0002, P < .0006B [after Bonferroni correction]; A vs S, P = .05, P = .15B; and S vs N, P = .03, P = .09B).

CONCLUSIONS

Amiodarone and sotalol achieved chemical cardioversion before planned electrical cardioversion in 26% and 19% of patients, respectively. After successful cardioversion, amiodarone appears better than sotalol at maintaining SR at 6 months.

Amiodarone lung toxicity in a cardiac transplant candidate initially diagnosed by fine-needle aspiration: Cytologic, histologic, and electronmicroscopic findings

A cardiac transplant candidate with ischemic cardiomyopathy developed bilateral small parenchymal opacities in lower lobes of the lung. A fine-needle aspiration (FNA) was performed that revealed changes characteristic of amiodarone toxicity. Subsequently performed lung biopsies and electron microscopic studies confirmed the initial FNA diagnosis. The patient has been successfully transplanted with marked improvement in his clinical findings. This is the first case of amiodarone lung toxicity where the diagnosis was initially suggested based on the FNA findings. We also describe the clinical, cytological, histological, and electron microscopic (EM) findings of amiodarone-related pulmonary toxicity and provide a review of the literature.

O uso de carbonato de lítio no tratamento da tireotoxicose induzida por amiodarona

Dentre as disfunções tireoidianas induzidas por amiodarona, a tireotoxicose é a mais grave e associada a maior morbi-mortalidade. O tratamento consiste no emprego de altas doses de drogas antitireoidianas e corticoesteróides, de forma isolada ou combinada. Outras terapias associadas foram propostas para o tratamento dos casos refratários. Relatamos o caso de um paciente de 40 anos com história de miocardiopatia dilatada idiopática que desenvolveu um quadro grave de tireoidite induzida por amiodarona após transplante cardíaco. Este paciente não respondeu à terapia inicial com doses altas de droga antitireoidiana e corticoesteróides, sendo, então, associado o carbonato de lítio em baixas doses e por curto período de tempo, o que resultou na normalização da função tireoidiana. Neste caso, o emprego do carbonato de lítio mostrou-se como uma terapia adjuvante eficaz e segura no controle da tireotoxicose induzida por amiodarona.

New Antiarrhythmic Drugs for Prevention of Atrial Fibrillation

Enhanced understanding of the mechanisms underlying atrial fibrillation (AF) and advent of catheter-based therapy for AF has altered the approach to patients with this most common arrhythmia. However, despite the success of aggressive procedural techniques, pharmacologic therapy remains the first-line and mainstay approach in the treatment of AF. This review of new antiarrhythmic drug (AAD) therapy for AF provides an in-depth overview of recently available classic and new investigational drugs being considered for AF treatment. Currently available AADs are associated with less than satisfactory efficacy in preventing AF and a significant side effect profile, including ventricular proarrhythmia. Recent investigations have focused on development of new AADs that, hopefully, will be more effective and safer even in patients with structural heart disease. These new AADs include selective multi-ion channel and atrial specific blockers and agents that target the underlying etiologies and substrate alterations that lead to AF. Included among the latter new category are agents that suppress activation of the renin-angiotensin-aldosterone system or inflammation, which represent novel targets for drug therapy for AF. Finally, new selective A1 adenosine receptor agonists may offer the possibility of more specific and successful ventricular rate control during AF. There is considerable hope and interest that improved understanding of AF mechanisms ultimately will result in more effective and less dangerous pharmacologic therapy becoming available in the future.

Long-Term Comparison of the Implantable Cardioverter Defibrillator Versus Amiodarone

Background— The implantable cardioverter defibrillator (ICD) is superior to amiodarone for secondary prophylaxis of sudden cardiac death. However, the magnitude of this benefit over long-term follow-up is not known. Thus, our objective was to evaluate the long-term consequences of using amiodarone versus an ICD as first-line monotherapy in patients with a prior history of sustained ventricular tachycardia/ventricular fibrillation or cardiac arrest.

Methods and Results— A total of 120 patients were enrolled at St Michael’s Hospital in the Canadian Implantable Defibrillator Study (CIDS) and were randomly assigned to receive either amiodarone (n=60) or an ICD (n=60). The treatment strategy was not altered after the end of CIDS unless the initial assigned therapy was not effective or was associated with serious side effects. After a mean follow-up of 5.6±2.6 years, there were 28 deaths (47%) in the amiodarone group, compared with 16 deaths (27%) in the ICD group ( P =0.0213). Total mortality was 5.5% per year in the amiodarone group versus 2.8% per year in the ICD group (hazard ratio of amiodarone: ICD, 2.011; 95% confidence interval, 1.087 to 3.721; P =0.0261). In the amiodarone group, 49 patients (82% of all patients) had side effects related to amiodarone, of which 30 patients (50% of all patients) required discontinuation or dose reduction; 19 patients crossed over to ICD because of amiodarone failure (n=7) or side effects (n=12).

Conclusions— In a subset of CIDS, the benefit of the ICD over amiodarone increases with time; most amiodarone-treated patients eventually develop side effects, have arrhythmia recurrences, or die.

Anti-arrhythmic efficacy of nifekalant hydrochloride, a pure class III anti-arrhythmic agent, in patients with healed myocardial infarction and inducible sustained ventricular tachycardia

In recent clinical trials, class III anti-arrhythmic drugs were found to reduce arrhythmic deaths in patients after myocardial infarction. The purpose of this study was to assess the electrophysiologic properties and anti-arrhythmic efficacy for inducible sustained ventricular tachycardias (VTs) of the pure class III agent nifekalant hydrochloride (MS-551) in comparison with those of procainamide. Programmed ventricular stimulation of up to three extra stimuli was performed for induction of VTs. Effective refractory period (ERP) of the ischemic zone and normal zone was also measured before and after nifekalant. Nifekalant and procainamide suppressed sustained VT induction in four of 15 patients and in six of 15 patients, respectively (p = NS). Sinus cycle length, PR interval, and QRS duration were not changed, but QT and QTc intervals were significantly increased with nifekalant (p < 0.01). Ventricular ERP also increased, whereas there were no significant differences in the increase of ERP between the ischemic and normal zones. The suppression of VT induction did not correlate with the changes in QT, QTc, and ERP after nifekalant administration. There were no significant differences in induced VT cycle length at baseline study between responders and nonresponders to nifekalant. Reverse use dependence was not apparent on review of electrophysiologic parameters. Neither proarrhythmic events nor hemodynamic disturbances occurred after nifekalant administration. It was concluded that nifekalant could be used safely and showed comparable effectiveness to procainamide for the suppression of VT induction.

Adverse dermatologic effects of cardiovascular drug therapy: part II

Cardiovascular disease is common, affecting an increasing number of persons as the population ages. To combat this growing health problem, physicians use a multitude of medications in the treatment of their patients. Although pharmacologic therapy greatly enhances quality of life for a majority of patients, there is always the potential for an unfavorable reaction. For example, cardiovascular drugs can induce a vast array of adverse dermatologic responses. This article reviews the various cutaneous reaction patterns that can occur as a result of treatment with class III, IV, and other antiarrhythmic agents, ACE inhibitors, Angiotensin II receptor blockers, and diuretics.

HRCT findings of amiodarone pulmonary toxicity: clinical and radiologic regression

Amiodarone is an antiarrhythmic drug that can cause interstitial pneumonitis leading to pulmonary fibrosis. A 62-year-old man suffering from atrial fibrillation and recurrent dyspnea was treated with amiodarone. After 15 months of treatment, HRCT revealed bilateral interstitial and alveolar opacifications with high-attenuating pleural-parenchymal consolidations, suggesting amiodarone induced pneumonitis. Three months after cessation of amiodarone treatment, HRCT shows complete regression of pneumonitis. Amiodarone pneumonitis can be misinterpreted and mistreated in patients with further underlying diseases. The present case report demonstrates the diagnostic value of HRCT in the diagnosis of interstitial pneumonitis.

Control of paroxysmal atrial fibrillation recurrence using combined administration of propafenone and quinidine

The frequent recurrence of paroxysmal atrial fibrillation (PAF) despite the use of standard antiarrhythmic agents prompted the use of new therapeutic approaches. There are few data on systematic assessment of PAF control with stepwise dose escalation and the use of a drug combination. Low-dose quinidine may promote the efficacy of propafenone by inhibiting its degradation through the cytochrome P450 pathway (CYP2D6). We prescribed propafenone 300 to 450 mg/day to 60 patients with PAF for 8 weeks, and 62% were symptomatically controlled. The 19 refractory patients were randomized in a double-blinded fashion to receive either a higher dose of propafenone (450 to 675 mg/day) or the standard dose of propafenone with low-dose quinidine 150 mg/day, each for an 8-week study period, and subsequently crossed over to the alternative treatment. The resulting serum propafenone concentrations were 259 +/- 208 and 336 +/- 237 mg/day (p >0.5), respectively. Both treatment arms prolonged the time to the first symptomatic atrial fibrillation (AF) recurrence and the interval between attacks, and AF was controlled in 37% of patients. However, the higher dose of propafenone was associated with gastrointestinal side effects not present with the low-dose quinidine combination. Of the 10 refractory patients, 7 were further controlled with a standard dose of propafenone plus quinidine (600 mg/day). Overall, control of PAF was achieved in 85% of patients at the end of 8 months; adverse effects necessitating withdrawal were observed in 6%, and uncontrolled AF in 5% of patients. There was no difference in the mean AF rate during recurrences in all phases, and ventricular proarrhythmia was not seen. This study documents the role of stepwise antiarrhythmic treatment of PAF. The use of a standard dose of propafenone, followed by low-dose quinidine combination to reduce propafenone degradation, and the combined standard dose of propafenone and quinidine may be used to maximize efficacy and tolerability.

A characterization of amiodarone-induced pulmonary toxicity in F344 rats and identification of surfactant protein-D as a potential biomarker for the development of the toxicity

Amiodarone (AD) is gaining support as a first-line antiarrhythmic drug despite its potentially fatal pulmonary toxicity involving inflammation and fibrosis. The goals of this study were to characterize a rat model of AD-induced pulmonary toxicity (AIPT) and identify a serum biomarker to aid in the diagnosis of the onset of pulmonary toxicity. Male F344 rats were instilled intratracheally with AD (6.25 mg/kg with a 3.125 mg/ml solution) in sterile water or the sterile water vehicle on days 0 and 2, a protocol that led to the development of pulmonary fibrosis on day 28 in the AD-treated animals. Animals were killed on days 3, 5, 6, 7, or 10 and bronchoalveolar lavage (BAL) was performed. Recovery of alveolar macrophages and eosinophils was increased on days 3 and 5, while neutrophil recovery and albumin levels in the first BAL fraction were significantly elevated only on day 3. BAL cells recovered from AD-treated rats at day 3 produced more phorbol myristate acetate-stimulated luminol-dependent chemiluminescence (LDCL) over 20 min than BAL cells from control rats. Experiments using specific inhibitors implicated superoxide and nitric oxide in at least part of the LDCL response. Serum levels of surfactant protein-D (SP-D), a surfactant-associated protein, were increased concurrently with the inflammatory response in the lungs. These findings indicate that this model exhibits transient pulmonary inflammation and damage, with the potential for elevated oxidant production in the lungs and subsequent pulmonary fibrosis. Also, SP-D is proposed as a specific biomarker to monitor the onset of AIPT in this model.

Dofetilide, a new class III antiarrhythmic agent

Dofetilide is a new antiarrhythmic agent recently approved for conversion and maintenance of sinus rhythm in patients with atrial fibrillation (AF) and atrial flutter (AFl). It is a class III antiarrhythmic that works by selectively blocking the rapid component of the delayed rectifier outward potassium current. Dofetilide prolongs the effective refractory period in accessory pathways, both anterograde and retrograde. This can be seen on the electrocardiogram through a dose-dependent prolongation of the QT and QTc intervals, with parallel increases in ventricular refractoriness. Approximately 80% of drug is excreted in urine, so dosing must be based on creatinine clearance. The elimination half-life is approximately 10 hours. In clinical trials dofetilide was superior to flecainide in converting patients with AFl to normal sinus rhythm (NSR; 70% vs 9%, p<0.01). It also was more effective than sotalol in converting patients with both AF and AFl to NSR (29% vs 6%, p<0.05) and maintaining them in NSR for up to 1 year. Most patients converted within 24-36 hours. Dofetilide has a favorable risk:benefit profile. Torsades de pointes is the most serious side effect; it occurs in 0.3-10.5% of patients and is dose related. To minimize the risk of induced arrhythmia, patients who start or restart the drug should be hospitalized a minimum of 3 days for creatinine clearance measurements, continuous electrocardiographic monitoring, and cardiac resuscitation, if necessary.

Amiodarone toxicity in a patient with simultaneous involvement of cornea, thyroid gland, and lung

Amiodarone, an iodine-rich benzofuran derivative, is a highly effective agent for the prophylaxis and treatment of cardiac arrhythmias, but it is associated with numerous side effects. Amiodarone toxicity involving several organs simultaneously has rarely been reported heretofore. In this report, we describe a case of a 73-year-old man who developed symptomatic hypothyroidism, pulmonary toxicity, and vortex epitheliopathy of the cornea during 6 months of amiodarone therapy for frequent palpitation and angina after myocardial infarction. This case illustrates that amiodarone may cause toxicity involving several organs concurrently in a patient receiving long-term amiodarone therapy. This may be of clinical significance in managing such patients.

Duration of preoperative amiodarone treatment may be associated with postoperative hospital mortality in patients undergoing heart transplantation

OBJECTIVE

To assess the effect of preoperative amiodarone treatment on patient mortality after heart transplantation.

DESIGN

Retrospective study.

SETTING

Single-institution university hospital.

PARTICIPANTS

One hundred six consecutive patients with heart transplants.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were grouped according to duration of preoperative amiodarone treatment, and posttransplant mortality before hospital discharge was compared with patients not treated with amiodarone. The authors collected cardiovascular data in the preoperative and postoperative periods. There was a significant increase in posttransplant mortality before hospital discharge in patients treated with amiodarone for more than 4 weeks in the preoperative period (p < 0.05). Patients treated with amiodarone had significantly lower (p < 0.05) heart rates (mean heart rate, 103+/-19 beats/min) in the early postoperative period than patients not treated with amiodarone (mean heart rate, 111+/-15 beats/min), but there was no relationship with mortality (p = not significant). Patients who died had a significantly lower (p < 0.05) postoperative cardiac index (2.2+/-0.7 to 2.5+/-0.7) in the first 24 hours after cardiopulmonary bypass compared with patients who survived to hospital discharge (3.0+/-0.7 to 3.1+/-0.9), but there was no relationship to amiodarone treatment (p = not significant).

CONCLUSION

Preoperative amiodarone treatment for more than 4 weeks may be associated with a significant increase in postoperative mortality in patients undergoing heart transplantation. Therefore, the indications for amiodarone must be carefully considered and, if needed, the maintenance dose should be kept to a minimum.

Health-related quality-of-life assessment of patients with life-threatening ventricular arrhythmias

The purpose of this study was to determine whether treatments for life-threatening ventricular arrhythmias are associated with quality-of-life (QOL) and psychological distress. Multidimensional measures of QOL and psychological distress were used to cross-sectionally compare patients with ICDs to patients treated with antiarrhythmic drugs and patients without serious cardiac conditions. The sample consisted of 157 patients: 35 patients treated with antiarrhythmic medication only, 24 patients treated with ICD only, 25 patients treated with ICD and antiarrhythmic medication, and 73 controls. Patients completed the Medical Outcomes Study SF-36 health survey, the Brief Symptom Inventory, and background questionnaires. There were no significant differences in self-reported QOL and psychological distress between patients with or without ICD, and the occurrence of defibrillator shocks was unrelated to QOL and psychological distress. However, patients treated with antiarrhythmic drugs reported greater QOL impairment in physical functioning, vitality, emotional role limitations, and sleep, as well as greater psychological distress than patients not treated with antiarrhythmics. These limitations may be attributed to adverse effects arising from antiarrhythmic pharmacotherapy. Results of the present investigation suggest that QOL and psychological distress are maintained among ICD patients, whereas treatment with antiarrhythmic drugs are associated with a diminished QOL and greater psychological distress. These findings may assist cardiologists to select the optimal treatment for life-threatening ventricular arrhythmias that minimizes disturbances in health-related QOL and psychological distress and increases patient compliance.

Stroke patients: do they have a predilection for extrapyramidal side effects from amiodarone?

This report describes two patients with recent stroke who, upon transfer to the rehabilitation medicine service, were noted to have extrapyramidal features. Both patients were receiving amiodarone for management of atrial fibrillation. When this medication was discontinued, there was slow resolution of extrapyramidal features and an improvement in function. Physicians managing acute stroke patients should be alert for features of amiodarone neurotoxicity, because these side effects may occur more readily in patients with recent neurologic impairment and may impede their progress in rehabilitation.

Unexpected instant death following successful coronary artery bypass graft surgery (and other clinical settings): atrial fibrillation, quinidine, procainamide, et cetera, and instant death

Primum non nocere. Atrial fibrillation (AF) occurs commonly following coronary artery bypass graft surgery, although new onset atrial fibrillation in this setting is usually transient. When AF reverts or is converted to sinus rhythm it is unlikely to recur, whether or not the patient takes preventive medication. As no benefit (and sometimes increased risk) associated with reduced mortality or morbidity in this setting has been reported for antiarrhythmic agents, standard treatment should consist of observation or control of ventricular response with an appropriate agent until AF relapses to sinus rhythm. If an antiarrhythmic agent, especially a class I agent, is used because of persistent or recurrent AF in the early postoperative period, heart rhythm should be monitored as long as the class I agent is administered and treatment initiated if an undersirable rhythm develops. Atrial fibrillation in other clinical settings in patients with structural heart disease presents a more difficult management problem. Class I agents are reported to be associated with an increased risk of death, despite an efficacious effect of maintaining sinus rhythm. Amiodarone is reported to be well tolerated with respect to the cardiovascular system, but unacceptable noncardiac effects are reported. A safe amiodarone-like agent is greatly needed. Atrial fibrillation in patients with no structural heart disease is not discussed in this presentation.

Cost-effectiveness analysis of invasive and noninvasive tests in high risk patients treated with amiodarone after acute myocardial infarction

OBJECTIVES

We sought to evaluate 1) the cost-effectiveness of amiodarone therapy in postinfarction patients; and 2) the influence of alternative diagnostic strategies (noninvasive only vs. noninvasive and electrophysiologic testing) on survival benefit and cost-effectiveness ratio of amiodarone therapy.

BACKGROUND

The cost-effectiveness of amiodarone therapy in postinfarction patients is still unknown, and no study has determined which diagnostic strategy should be used to maximize amiodarone survival benefit while improving its cost-effectiveness ratio.

METHODS

We designed a postinfarction scenario wherein heart rate variability analysis on 24-h Holter monitoring was used as a screening test for 2-year amiodarone therapy in a cohort of survivors (mean age 57 years) of a recent myocardial infarction. Three different therapeutic strategies were compared: 1) no amiodarone; 2) amiodarone in patients with depressed heart rate variability; 3) amiodarone in patients with depressed heart rate variability and a positive programmed ventricular stimulation. Total variable costs and quality-adjusted life expectancy during a 20-year period were predicted with use of a Markov simulation model. Costs and charges were calculated with reference to an Italian and American hospital.

RESULTS

Amiodarone therapy in patients with depressed heart rate variability and a positive programmed ventricular stimulation was dominated by a blend of the two alternatives. Compared with the no-treatment strategy, the incremental cost-effectiveness ratio of amiodarone therapy in patients with depressed heart rate variability was $10,633 and $39,422 per gained quality-adjusted life-year using Italian costs and American charges, respectively.

CONCLUSIONS

Compared with a noninterventional option, amiodarone prescription in all patients with depressed heart rate variability seems to be a more appropriate approach than the alternative based on the combined use of heart rate variability and electrophysiologic study.

Adverse effects of amiodarone

Amiodarone was introduced 30 years ago as an antianginal agent and subsequently has been used as an antiarrhythmic agent. This drug was initially used for patients with malignant ventricular arrhythmias; however, currently it is being used broadly for rate and rhythm control in patients with atrial fibrillation. At first, amiodarone was primarily used by cardiologists and today it is used throughout the medical profession. Amiodarone therapy can potentially result in a wide range of adverse effects. The majority of these adverse effects are dose related and reversible. The following is a review of the adverse effects and drug interactions of amiodarone along with recommendations for identification and management of these adverse effects.

Continuous home ambulatory intravenous inotropic drug therapy in severe heart failure: safety and cost efficacy

Some patients with dilated cardiomyopathy who are inotrope dependent but remain well by undergoing infusions can be managed by ambulatory infusions at home. We report our results in 20 patients awaiting heart transplantation, unable to be weaned from intravenous inotropic therapy on 2 or more occasions, but who were well while receiving inotropes and received home ambulatory infusions. The patients were treated with ACE inhibitors, digoxin, diuretics, vasodilators, close electrolyte management, and low-dose amiodarone for those with more than four-beat ventricular tachycardia. Infusions were delivered by a tunneled subclavian catheter and syringe driver. Thirteen patients received dopamine, four received dobutamine, and three received both. Mean duration of inotropic therapy was 5 months with 70% of the time spent as an outpatient. Eleven patients received transplants, two remain on the waiting list, and seven died after being removed from the list because of general deterioration or renal dysfunction. There were no sudden deaths. Actuarial survival was 71% at 3 months, which is not less than that expected for an inotrope-dependent population. All patients with idiopathic dilated cardiomyopathy survived to transplantation. In contrast, all three with right heart failure caused by pulmonary vascular disease and four of seven with ischemic cardiomyopathy died. Inpatient days were reduced by 70%, leading to considerable cost savings. Home ambulatory inotropic therapy is safe, cost-effective, best suited to those with idiopathic dilated cardiomyopathy, and dramatically reduces inpatient hospital duration.

The side effect profile of class III antiarrhythmic drugs: focus on d,l-sotalol

Class III antiarrhythmic drugs have been under extensive clinical investigation as safer, more effective alternatives to class I drugs, which have recognized risks in selected populations. Class III drugs prolong the action potential duration of myocardial cells, resulting in a lengthening of the effective refractory period. This pharmacologic activity has antiarrhythmic properties, but it may induce a distinctive form of proarrhythmia known as torsades de pointes. Amiodarone and d,l-sotolol are class III drugs that have been available for many years. In addition to their ability to prolong refractoriness, these drugs have other pharmacodynamic properties. Recent antiarrhythmic drug discovery has focused on the identification and development of selective or so-called pure class III drugs that are devoid of additional actions. Investigators have hoped that these drugs would be as effective as sotalol and amiodarone but have fewer adverse effects. Accumulating data, however, indicate that complex compounds exhibiting antiadrenergic and other electrophysiologic properties may be superior to pure class III agents.