Toxicity in Doberman Pinchers with Ventricular Arrhythmias Treated with Amiodarone (1996-2005)

Efficacy and safety of different antiarrhythmic protocols used for rate control in dogs with secondary atrial fibrillation

INTRODUCTION/OBJECTIVES

Studies comparing the effects of antiarrhythmic protocols used for rate control in dogs with secondary atrial fibrillation (AF) are currently limited; therefore, this study aimed to report detailed data on the efficacy and therapy-related side-effects (TRSEs) of different antiarrhythmic protocols in dogs with secondary AF.

ANIMALS, MATERIALS, AND METHODS

Dogs with secondary AF treated with combination therapy with diltiazem and digoxin (CTDilt+Digox), diltiazem monotherapy (MTDilt), digoxin monotherapy (MTDigox), or amiodarone monotherapy (MTAmiod) were retrospectively evaluated. Signalment, clinical, diagnostic, therapeutic, and outcome data were retrieved. Electrocardiographically, antiarrhythmic efficacy was defined by a reduction in the mean heart rate on Holter monitoring ≤125 beats/minutes. Statistical analysis was performed to compare selected data, including the rate of efficacy and TRSEs as well as the median survival time, between dogs treated with different antiarrhythmic protocols.

RESULTS

Fifty-four dogs were included, with 28 receiving the CTDilt+Digox and 26 receiving monotherapies (MTDigox = 16; MTDilt = 5; MTAmiod = 5). The efficacy rate documented in dogs treated with CTDilt+Digox was significantly higher than that observed in dogs from the composite monotherapy group (i.e., MTDilt+MTDigox+MTAmiod) (P=0.048). The rate of TRSEs documented in dogs treated with CTDilt+Digox was similar to that observed in dogs from the composed monotherapy group (P=0.129). The median survival time documented in dogs treated with CTDilt+Digox was significantly longer than that observed in dogs of the MTDigox group (P=0.01).

DISCUSSION

In dogs with secondary AF we included, CTDilt+Digox was well tolerated and provided clinically relevant benefits compared to the use of a single antiarrhythmic drug.

LIMITATIONS

Retrospective design; heterogeneous sample size of categories analyzed; clinicopathological data available for many, but not all, dogs.

CONCLUSIONS

Our findings support the indication to generally consider CTDilt+Digox as a first-line antiarrhythmic treatment in dogs with secondary AF.

Amiodarone treatment in cats: evaluation of indications, adverse effects, and survival outcomes

Introduction

Time-and dose-dependent adverse effects of amiodarone have not been described in cats. The primary aim of this retrospective multicenter cohort study was to report the type and frequency of clinical adverse effects and biochemical changes in cats receiving amiodarone chronically. The secondary aim was to report survival outcomes in this population of cats.

Methods

Medical records were reviewed for signalment, arrhythmia diagnosis, presence of structural heart disease, systemic comorbidities and congestive heart failure at presentation, amiodarone dose, serial bloodwork results, adverse events, and survival outcome.

Results

The study population included 27 client-owned cats (2016-2022). All cats had structural cardiac disease, and many were in congestive heart failure (17/27; 63%) at presentation. Amiodarone was most commonly prescribed for ventricular tachycardia (19/27, 70%), and it was administered once daily with a median [range] dose of 8.8 [4.515.2] mg/kg/day. There was a decrease in serum concentration of alanine transaminase between pretreatment values and values measured during the early amiodarone treatment window, 1-90 days (n = 16; p = 0.034). No statistical difference in serum concentration of alanine transaminase (n = 10; p = 0.799) was noted after 90 days of treatment compared to pretreatment. There was no change in hematocrit, neutrophil count, and serum concentration of alkaline phosphatase and total thyroxine during treatment in assessed cats. Ten cats (37%) had at least one episode of hyporexia or vomiting while receiving amiodarone. The median survival time for all-cause mortality was 441 days (95% confidence interval, 126-929 days); cats in which the primary therapeutic target was both supraventricular and concomitant ventricular tachyarrhythmias had at least a two-fold risk of dying compared to cats with supraventricular tachyarrhythmias alone (hazard ratio 12.9, 95% CI 1.86-89.8; p = 0.010).

Discussion

Amiodarone was primarily used to treat ventricular arrhythmias. Transient gastrointestinal signs were reported in approximately one-third of the cats studied, but no clinically significant laboratory abnormalities were found in cats receiving amiodarone.

Efficacy and safety of antiarrhythmic therapy in dogs with naturally acquired tachyarrhythmias treated with amiodarone or sotalol: a retrospective analysis of 64 cases

INTRODUCTION/OBJECTIVE

Studies on the use of amiodarone or sotalol are limited in dogs. Therefore, this study aimed to provide data on the efficacy and safety of these drugs in dogs with ventricular tachyarrhythmia (VT) and/or supraventricular tachyarrhythmia (SvT).

ANIMALS, MATERIALS, AND METHODS

Dogs with VT and/or SvT treated with amiodarone or sotalol as a first-line therapy were retrospectively evaluated. Signalment, clinical, diagnostic, therapeutic, and outcome data were retrieved. For VT, efficacy was demonstrated through a decrease of the Lown-Wolf grade to less than five or a reduction of at least 85% in the number of ventricular premature complexes observed on Holter monitoring. For SvT, efficacy was represented by cardioversion or a reduction in the mean heart rate on Holter monitoring ≤140 beats/min. Treatment-related side effects (TRSEs) were classified as clinically relevant and irrelevant. Statistical analysis was performed to compare data before and after antiarrhythmic prescription.

RESULTS

Sixty-four dogs were included. Amiodarone and sotalol were efficacious in treating both VT (85.7% and 90.0% of cases, respectively) and SvT (75% and 71.4% of cases, respectively). No significant differences were found when comparing their efficacy rates in dogs with VT and SvT (P=0.531 and 0.483, respectively). Clinically relevant TRSEs were rare with both amiodarone and sotalol (8.3% and 5% of cases, respectively), while clinically irrelevant TRSEs occurred more frequently with amiodarone (29.2%) than with sotalol (10%).

DISCUSSION

In dogs with tachyarrhythmias, amiodarone and sotalol are generally efficacious and safe, as clinically relevant TRSEs seem rare.

CONCLUSIONS

This study provides novel data on the effects of amiodarone and sotalol in dogs with tachyarrhythmias.

An environmental life cycle comparison of various sandwich composite panels for railway passenger vehicle applications

This study reports the results of a comparison made using life cycle assessment (LCA) analysis of the environmental impact of nine different sandwich material models (SMs). The objective is to reveal whether the candidate materials considered for a railway passenger vehicle (conventional or high-speed train) are green/environmentally friendly or not. For this aim, life cycle approach enables to take into account the light weighting gain without disregarding the environmental impact of manufacturing process. These SMs are designed as combinations of existing traditional and candidate materials, such as steel, aluminium, carbon/glass fibre-reinforced plastics (CFRP/GFRP), aluminium honeycomb, and polymer foam core. The environmental performance of these nine different models has been calculated via the LCA analysis with CML-IA v.3.0 impact assessment methodology in a SimaPro 8.5.0. The system boundaries in the LCA analysis include "cradle to grave" process of sandwich composite materials in the railway passenger vehicle. The functional unit was selected as "one product of SM" for each configuration; besides, this panel has a lifetime span of 25 years at 400,000 vehicle-km per year in the vehicle operation. The results show that the use-phase, which dominates the environmental impact of the SMs of the railway passenger vehicle car body, is itself largely affected by electricity generation. In particular, the mass reduction in the models also achieved a reduction in environmental impact over its lifetime, mainly owing to decreased energy consumption. Another important finding regarding the manufacture of certain models (such as CFRP and GFRP) for lightweight design, is that assessment, based solely on mass reduction, may not always have better environmental performance or be reliable due to the manufacturing impact.

Successful management of ventricular fibrillation and ventricular tachycardia using defibrillation and intravenous amiodarone therapy in a cat

OBJECTIVE

To describe the successful management of ventricular fibrillation (VF) and ventricular tachycardia (VT) using cardiopulmonary resuscitation, including defibrillation, followed by continuous rate infusion of IV amiodarone, in a cat with cardiac arrest secondary to tachyarrhythmia.

CASE SUMMARY

A 12-year-old previously healthy neutered male Scottish Fold cat presented following an acute episode of collapse. Initial physical examination revealed severe tachycardia and cardiovascular collapse. Within a few minutes after arrival, the cat experienced cardiopulmonary arrest. Electrocardiographic assessment was suggestive of VF, and CPR was initiated, including 2 rounds of defibrillation (2 joule/kg each), resulting in return of spontaneous circulation with sustained VT. After procainamide and lidocaine failed to result in conversion to normal sinus rhythm (NSR), continuous IV amiodarone therapy was initiated, and NSR was achieved. Echocardiography demonstrated severe systolic dysfunction, and tachycardia-induced cardiomyopathy (TICM) secondary to chronic VT was suspected; however, dilated cardiomyopathy (DCM) or end-stage hypertrophic cardiomyopathy could not be ruled out. The patient was discharged the following day with oral amiodarone and pimobendan. During a recheck examination performed 7 months later the cat was in NSR, with no direct evidence of long-term amiodarone adverse effects. The cat died acutely at home 8 months after discharge.

NEW OR UNIQUE INFORMATION PROVIDED

This report is the first to describe the successful use of IV amiodarone in a cat to manage sustained VT following CPR.

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Predictors of Sudden Cardiac Death in Doberman Pinschers with Dilated Cardiomyopathy

Background

Doberman Pinschers with dilated cardiomyopathy (DCM) are at high risk of sudden cardiac death (SCD). Risk factors for SCD are poorly defined.

Aim

To assess cardiac biomarkers, Holter‐ECG, echocardiographic variables and canine characteristics in a group of Doberman Pinschers with DCM dying of SCD and in a DCM control group to identify factors predicting SCD.

Methods/Animals

A longitudinal prospective study was performed in 95 Doberman Pinschers with DCM. Forty‐one dogs died within 3 months after the last cardiac examination (SCD‐group) and were compared to 54 Doberman Pinschers with DCM surviving 1 year after inclusion. Holter‐ECG, echocardiography, measurement of N‐terminal prohormone of brain‐natriuretic peptide (NT‐proBNP), and cardiac Troponin I (cTnI) concentrations were recorded for all dogs.

Results

Volume overload of the left ventricle (left ventricular end‐diastolic volume (LVEDV/BSA) > 91.3 mL/m²) was the single best variable to predict SCD. The probability of SCD increases 8.5‐fold (CI_0.95 = 0.8–35.3) for every 50 mL/m²‐unit increment in LVEDV/BSA. Ejection fraction (EF), left ventricular end‐systolic volume (LVESV/BSA) and NT‐proBNP were highly correlated with LVEDV/BSA (r = −0.63, 0.96, 0.86, respectively). Generated conditional inference trees (CTREEs) revealed that the presence of ventricular tachycardia (VT), increased concentration of cTnI, and the fastest rate (FR) of ventricular premature complexes (VPC) ≥260 beats per minute (bpm) are additional important variables to predict SCD.

Conclusion

Conditional inference trees provided in this study might be useful for risk assessment of SCD in Doberman Pinschers with DCM.

Ability of a 5-minute electrocardiography (ECG) for predicting arrhythmias in Doberman Pinschers with cardiomyopathy in comparison with a 24-hour ambulatory ECG

BACKGROUND

Ventricular premature contractions (VPCs) are common in the occult stage of cardiomyopathy in Doberman Pinschers. Although the gold standard for detecting arrhythmia is the 24-hour ambulatory electrocardiography (ECG) (Holter), this method is more expensive, time-consuming and often not as readily available as common ECG.

OBJECTIVES

Comparison of 5-minute ECGs with Holter examinations.

ANIMALS

Eight hundred and seventy-five 5-minute ECGs and Holter examinations of 431 Doberman Pinschers.

METHODS

Each examination included a 5-minute ECG and Holter examination. A cut-off value of > 100 VPCs/24 hours using Holter was considered diagnostic for the presence of cardiomyopathy. Statistical evaluation included calculation of sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

Holter examinations revealed > 100 VPCs/24 hours in 204/875 examinations. At least 1 VPC during a 5-minute ECG was detected in 131 (64.2%) of these 204 examinations. No VPCs were found in the 5-minute ECG in 73 (35.8%) examinations of affected Doberman Pinschers. A 5-minute ECG with at least 1 VPC as cut-off had a sensitivity of 64.2%, a specificity of 96.7%, a positive predictive value of 85.6% and a negative predictive value of 89.9% for the presence of > 100 VPCs/24 hours.

CONCLUSIONS AND CLINICAL IMPORTANCE

A 5-minute ECG is a rather insensitive method for detecting arrhythmias in Doberman Pinschers. However, the occurrence of at least 1 VPC in 5 minutes strongly warrants further examination of the dog, because specificity (96.7%) and positive predictive value (85.6%) are high and could suggest occult cardiomyopathy.