Life-Threatening Cardiac Arrhythmias during Anesthesia and Surgery

Life-threatening arrhythmias are frequently encountered during anesthesia for cardiac or non-cardiac surgery. They result in a significant cause of morbidity and mortality, particularly in elderly patients. Predisposing factors like electrolytes abnormalities, pre-existing cardiac disease, intubation procedure, anesthetic medications, and various surgical stimulation need to be determined. Early diagnosis and commencement of an appropriate treatment protocol may be lifesaving. Treatment usually involves correction of the underlying causes, cardiac electroversion, and the use of one or more antiarrhythmic agents. Although ventricular tachycardia, ventricular fibrillation, torsade de pointes, and pulseless electrical activity are considered malignant arrhythmias that can lead to cardiac arrest, other types of Brady and tachyarrhythmias are also included in this chapter to enable adopting a more objective approach in the management of arrhythmias intraoperatively, avoiding risks of inappropriate management strategies.

Ivabradine–Flecainide as Breakthrough Drug Combination for Congenital Junctional Ectopic Tachycardia: A Case Report and Literature Review

Congenital junctional ectopic tachycardia (CJET) is a rare tachyarrhythmia that remains difficult to manage, with suboptimal control in most cases. Here, we report literature research on the use of ivabradine in the treatment of pediatric junctional ectopic tachycardia (JET), both congenital and postoperative, and describe the successful use of ivabradine–flecainide association for CJET therapy resistant to other antiarrhythmic agents. This new drug combination was effective in completely suppressing JET. Ivabradine–flecainide combination may be considered a new therapeutic strategy of CJET with a satisfactory efficacy/tolerability ratio in patients resistant to conventional drug combinations.

Attenuation and Structural Transformation of Crassicauline A During Sand Frying Process and Antiarrhythmic Effects of its Transformed Products

To ensure safety and efficacy, most Aconitum herbs should be processed before clinical application. The processing methods include boiling, steaming, and sand frying. Among these methods, the transformation pathways of diterpenoid alkaloids in the process of sand frying are more complicated. Therefore, crassicauline A, a natural product with two ester bonds, was chosen as the experimental object. Consequently, a known alkaloid, together with three new alkaloids, was derived from crassicauline A. Meanwhile, the cardiotoxicity of converted products was reduced compared with their parent compound. Interestingly, some diterpenoid alkaloids have similar structures but opposite effects, such as arrhythmia and antiarrhythmic. Considering the converted products are structural analogues of crassicauline A, herein, the antiarrhythmic activity of the transformed products was further investigated. In a rat aconitine-induced arrhythmia assay, the three transformed products, which could dose-dependently delay the ventricular premature beat (VPB) incubation period, reduce the incidence of ventricular tachycardia (VT), combined with the increasing arrhythmia inhibition rate, exhibited prominent antiarrhythmic activities. Our experiments speculated that there might be at least two transformation pathways of crassicauline A during sand frying. The structure-activity data established in this paper constructs the critical pharmacophore of diterpenoid alkaloids as antiarrhythmic agents, which could be helpful in searching for the potential drugs that are equal or more active and with lower toxicity, than currently clinical used antiarrhythmic drugs.

Safety and interaction of direct oral anticoagulants with antiarrhythmic drugs

The use of direct oral anticoagulants minimized the risks associated with vitamin K antagonist (warfarin) therapy. Currently, direct oral anticoagulants have priority over warfarin for the prevention of thromboembolic events in patients with atrial fibrillation and a number of other conditions requiring anticoagulant therapy. Direct oral anticoagulants along with antiarrhythmic therapy are the accepted strategy for atrial fibrillation treatment. At the same time, the effect of drug-drug interactions (DDI) between direct oral anticoagulants and antiarrhythmic drugs, which have common points of metabolic application, has not been fully elucidated. In order to provide effective and safe anticoagulant and antiarrhythmic therapy in patients with AF, it is important to understand the mechanisms and severity of DDI of direct oral anticoagulants and antiarrhythmic agents. This review discusses the issues of DDI of direct oral anticoagulants and antiarrhythmic drugs used to treat atrial fibrillation.

Classification of the mechanisms by which cardiotoxic plant poisons exert their effects

Episodes of poisoning due to plant-based toxins are an unusual presentation to the emergency department. Plant poisons may be ingested if the source plant is misidentified as benign (eg, Lily of the Valley being mistaken for wild garlic and water hemlock being mistaken for wild celery), or taken as part of a complementary medicine regime or otherwise for psychotropic effect. Numerous plant poisons demonstrate cardiotoxic effects resulting from action against cardiac myocyte ion channels, or other cardiac receptor targets. These mechanisms will produce stereotyped symptoms and including electrocardiogram (ECG) changes dependent on which ion channels or receptors are targeted. These mechanisms are stereotyped and may be grouped by toxidromic effect. This article proposes a novel classification of cardiotoxic plant poisons based on these actions. Given that these mechanisms mirror the Vaughan Williams classification used to categorise therapeutic antiarrhythmic agents, it is felt that this will serve as a mnemonic and diagnostic aid in clinical situations of cardiotoxic plant ingestion.

Analyzing Sex-Differences in Atrial Fibrillation Patients: Bias or Proper Management?

Background: There are inconsistent and conflicting data among males and females with AF. Objective: This study intends to analyze whether the sex-based differences among AF patients were influenced by age, co-morbidities, and treatment strategy rather than solely gender difference. Methods: We analyzed 327 consecutive patients admitted to the ED due to AF for three years and follow-up for a year. Results: Females with AF were older (p<.001), had higher BMI (p<.001), and a higher rate of co-morbidities as hypertension (p<.001), hyperlipidemia (p=0.01), Diabetes mellitus (p=0.05), valvular heart disease (p=0.05) and thyroid dysfunction (18.3% vs. 1.8%, p<.001). AF males had a higher rate of coronary disease (p<.001) and heart disease with reduced ejection fraction (p<.001). As a result, the mean CHADS2 and CHA2DS2-VASc scores were significantly higher in females (p<.001 for both). Female tends to be treated with rate control medications and less with antiarrhythmic agents (p<.001). Univariate analysis reveals that females had a higher rate of recurrent AF, heart failure hospitalization, CVA, and myocardial infarction. Yet, adjusting gender to age and co-morbidities shows that the females remain to have a higher rate of heart failure hospitalization (OR 2.73 95%CI 1.04-5.89, P-value <.001) and recurrent AF (OR 3.86, P-value =0.02). Thyroid dysfunction and the lack of antiarrhythmic treatment significantly increase the risk of AF (OR 5.95 95%CI 3.15-9.73, OR 3.42, respectively, P-value<.001 for both) regardless of gender. The mortality rate differs only in a sub-group of females ≥ 75 years of age (OR 1.60, P<.001). Conclusion AF males and females differ significantly in baseline characteristics. Females are older, have more co-morbidities, and tend to be treated unnecessarily differently for AF. Following age and co-morbidities adjustments, a female gender remains significant for heart failure hospitalization and recurrent AF. Thyroid dysfunction and AF treatment may explain the sex-based difference of recurrent AF.

Non-Persistence With Antiplatelet Medications Among Older Patients With Peripheral Arterial Disease

Introduction: Antiplatelet therapy needs to be administered life-long in patients with peripheral arterial disease (PAD). Our study was aimed at 1) the analysis of non-persistence with antiplatelet medication in older PAD patients and 2) identification of patient- and medication-related characteristics associated with non-persistence.Methods: The study data was retrieved from the database of the General Health Insurance Company. The study cohort of 9,178 patients aged ≥ 65 years and treated with antiplatelet medications was selected from 21,433 patients in whom PAD was newly diagnosed between 01/2012 and 12/2012. Patients with a 6 months treatment gap without antiplatelet medication prescription were classified as non-persistent. Characteristics associated with non-persistence were identified using the Cox regression.Results: At the end of the 5 years follow-up, 3,032 (33.0%) patients were non-persistent. Age, history of ischemic stroke or myocardial infarction, clopidogrel or combination of aspirin with clopidogrel used at the index date, higher co-payment, general practitioner as index prescriber and higher overall number of medications were associated with persistence, whereas female sex, atrial fibrillation, anxiety disorders, bronchial asthma/chronic obstructive pulmonary disease, being a new antiplatelet medication user (therapy initiated in association with PAD diagnosis), and use of anticoagulants or antiarrhythmic agents were associated with non-persistence.Conclusion: In patients with an increased probability of non-persistence, an increased attention should be paid to improvement of persistence.

Breaktrough drug combination for Congenital Junctional Ectopic Tachycardia: a pediatric case report.

Introduction: Congenital Junctional Ectopic Tachycardia (JET) is a rare tachyarrhythmia that remains difficult to manage with suboptimal control in the majority of cases. Methods: Here, we report the successful use of Ivabradine in combination with Flecainide for the therapy of congenital JET resistant to multiple antiarrhythmic agents. Results: This new drug combination was effective in completely suppressing JET . Conclusion: Ivabradine in combination with Flecainide may be considered a new therapeutic strategy of congenital JET with satisfactory efficacy/tolerability ratio in patients resistant to conventional drug combinations.