Ivabradine as a treatment option for junctional ectopic tachycardia in an adult female

A Junctional ectopic tachycardia diagnosis was performed using two electrophysiological maneuvers in an adult female with a narrow-complex supraventricular tachycardia with a bystander AV-node slow pathway conduction, who previously underwent catheter ablation attempts for an atrio-ventricular nodal re-entrant tachycardia misdiagnosis. The first maneuver was atrial entrainment with an atrial-His-His-atrial response. The second was based on the response to a premature atrial complex delivered at different phases of the tachycardia cycle confirming that anterograde slow pathway conduction and retrograde fast pathway were not involved. Considering that verapamil, diltiazem, bisoprolol + flecainide, and nadolol were ineffective, we tried ivabradine with no sustained arrhythmias during 18-months.

Effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction

BACKGROUND/INTRODUCTION

Heart failure patients with reduced ejection fraction are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes.

OBJECTIVE

The effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction patients has not been fully elucidated. The aim of this study was to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients with reduced ejection fraction patients.

METHODS

In this retrospective study, 1,639 patients with heart failure patients with reduced ejection fraction were included. Patients were divided into two groups: ivabradine users and nonusers. Patients presenting with ventricular tachycardia, the presence of ventricular extrasystole, and ventricular tachycardia in 24-h rhythm monitoring, appropriate implantable cardioverter-defibrillator shocks, and long-term mortality outcomes were evaluated according to ivabradine use.

RESULTS

After adjustment for all possible variables, admission with ventricular tachycardia was three times higher in ivabradine nonusers (95% confidence interval 1.5-10.2). The presence of premature ventricular contractions and ventricular tachycardias in 24-h rhythm Holter monitoring was notably higher in ivabradine nonusers. According to the adjusted model for all variables, 4.1 times more appropriate implantable cardioverter-defibrillator shocks were observed in the ivabradine nonusers than the users (95%CI 1.8-9.6). Long-term mortality did not differ between these groups after adjustment for all covariates.

CONCLUSION

The use of ivabradine reduced the appropriate implantable cardioverter-defibrillator discharge in heart failure patients with reduced ejection fraction patients. Ivabradine has potential in the treatment of ventricular arrhythmias in heart failure patients with reduced ejection fraction patients.

Experimental drugs for supraventricular tachycardia: an analysis of early phase clinical trials

INTRODUCTION

Supraventricular tachycardias (SVT) are a diverse group of commonly encountered arrhythmias arising at or above the atrioventricular (AV) node. Conventional anti-arrhythmic medications are restricted by extensive side-effect profiles and limited efficacy. Catheter ablation has emerged as a first-line therapy for many arrhythmias but is not a suitable option for all patients. This has prompted the exploration of novel pharmacological approaches targeting specific molecular mechanisms of SVT.

AREAS COVERED

This review article aims to summarize recent advancements in pharmacological therapeutics for SVT and their clinical implications. The understanding of molecular mechanisms underlying these arrhythmias, particularly atrial fibrillation, has opened up new possibilities for targeted interventions. Beyond the manipulation of ion channels and membrane potentials, pharmacotherapy now focuses on upstream targets such as inflammation, oxidative stress, and structural remodeling. This review strives to provide a comprehensive overview of recent advancements in pharmacological therapeutics directed at the management of SVT. We begin by providing a brief summary of the mechanisms and management of commonly encountered SVT before delving into individual agents, which in turn are stratified based on their molecular treatment targets.

EXPERT OPINION

The evolving landscape of pharmacologic therapy offers hope for more personalized and tailored interventions in the management of SVT.

Effects of Amiodarone and Esmolol for Heart Rate and Cardiovascular Changes

Objective

To probe into the effects of amiodarone and esmolol for heart rate disorders and myocardial infarction.

Methods

76 cases of cardiopathy in our hospital from July 2019 to October 2021 were analyzed for myocardial infarction. The control group applied amiodarone treatment. Blood pressure, treatment effect, adverse reactions, myocardial marker levels, electrocardiogram, and heart function indicators were compared.

Results

There were no statistical differences in two groups of diastolic pressure (P > 0.05). The analysis of the systolic pressure in the study group was greater than the control group (P < 0.05); The effective rate was higher than that of the control group (P < 0.05); the incidence of adverse reactions in the study group and control group was 28.95% and 31.58%, respectively, and there was no statistically significant difference between groups (P > 0.05). The standards of markers were significantly reduced compared with the control group (P < 0.05). After treatment, the heart rate of the two groups was significantly reduced, and the QT intervals were significantly shortened. But compared with the control group, reduction was larger in the research group (P < 0.05). Compared with the control group, the resolution rate was higher (P < 0.05). After treatment, the two groups of quality of life were significantly increased, and compared with the control group, the increase in the quality of life of the study group was greater (P < 0.05).

Conclusion

Application of amiodarone and esmolol joint treatment can improve the quality of life, improve the level of heart function and myocardial marker, and can reduce Q-T intervals and prognosis. Therefore, amiodarone and esmolol treatment is worth promoting.

The Bradycardic Agent Ivabradine Acts as an Atypical Inhibitor of Voltage-Gated Sodium Channels

Background and purpose: Ivabradine is clinically administered to lower the heart rate, proposedly by inhibiting hyperpolarization-activated cyclic nucleotide-gated cation channels in the sinoatrial node. Recent evidence suggests that voltage-gated sodium channels (VGSC) are inhibited within the same concentration range. VGSCs are expressed within the sinoatrial node and throughout the conduction system of the heart. A block of these channels thus likely contributes to the established and newly raised clinical indications of ivabradine. We, therefore, investigated the pharmacological action of ivabradine on VGSCs in sufficient detail in order to gain a better understanding of the pro- and anti-arrhythmic effects associated with the administration of this drug.

Experimental Approach: Ivabradine was tested on VGSCs in native cardiomyocytes isolated from mouse ventricles and the His-Purkinje system and on human Na_v1.5 in a heterologous expression system. We investigated the mechanism of channel inhibition by determining its voltage-, frequency-, state-, and temperature-dependence, complemented by a molecular drug docking to the recent Na_v1.5 cryoEM structure. Automated patch-clamp experiments were used to investigate ivabradine-mediated changes in Na_v1.5 inactivation parameters and inhibition of different VGSC isoforms.

Key results: Ivabradine inhibited VGSCs in a voltage- and frequency-dependent manner, but did not alter voltage-dependence of activation and fast inactivation, nor recovery from fast inactivation. Cardiac (Na_v1.5), neuronal (Na_v1.2), and skeletal muscle (Na_v1.4) VGSC isoforms were inhibited by ivabradine within the same concentration range, as were sodium currents in native cardiomyocytes isolated from the ventricles and the His-Purkinje system. Molecular drug docking suggested an interaction of ivabradine with the classical local anesthetic binding site.

Conclusion and Implications: Ivabradine acts as an atypical inhibitor of VGSCs. Inhibition of VGSCs likely contributes to the heart rate lowering effect of ivabradine, in particular at higher stimulation frequencies and depolarized membrane potentials, and to the observed slowing of intra-cardiac conduction. Inhibition of VGSCs in native cardiomyocytes and across channel isoforms may provide a potential basis for the anti-arrhythmic potential as observed upon administration of ivabradine.

The use of ivabradine in a patient with idiopathic ventricular arrhythmia originating from the left ventricular summit

Idiopathic ventricular arrhythmias (VA) are common and treatment options include anti-arrhythmic drugs (AAD) or catheter ablation. Patients presenting with idiopathic VA which is originating from the left ventricular summit (LVS) poses a particular challenge as the success for catheter ablation is low and AAD's may not be used long-term due to side effects. Ivabradine is an inhibitor of funny current (If) in cardiac pacemaker cells by blocking hyperpolarization-activated cyclic nucleotide-gated (HCN). In the present case, we reported the use of ivabradine in treatment of idiopathic VA which was originated from LVS and was resistant to multiple AAD's and catheter ablation.

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.

Diagnosis and management of junctional ectopic tachycardia in children

Junctional ectopic tachycardia (JET) is more common in its postoperative form. A thorough understanding of its etiology, pathophysiology, and management strategies is essential. Classically, postoperative JET is considered to arise from surgical trauma. Genetic susceptibility and an intrinsic morphologic/functional defect in the conduction system inherent in congenital heart diseases likely play a significant role. The devastating effects on postoperative hemodynamics warrant prompt attention. A multipronged management approach with general measures, pharmacotherapy, and pacing has decreased morbidity and mortality. Amiodarone and procainamide remain the preferred drugs, while ivabradine appears promising. Carefully planned randomized trials can go a long way in developing a systematic management protocol for postoperative JET.

Ivabradine: A Potential Therapeutic for Children With Refractory SVT

Background: In April 2015, ivabradine was approved by the Food and Drug Administration for the treatment of patients with coronary artery disease and heart failure (HF). The use of this medication has been linked with improved clinical outcomes and reduced rates of hospitalization in patients with symptomatic HF and a baseline heart rate of 70 bpm and above. Nonetheless, little is known about the use of ivabradine in pediatric patients with supraventricular tachycardia (SVT). This use is not well-studied and is only endorsed by a few case reports and case series.

Aim: This study discusses the off-label utilization of ivabradine in pediatric patients with SVT, and highlights its efficacy in treating treatment-resistant (refractory) SVT.

Methods: We conducted a retrospective single-center observational study involving pediatric patients with SVT treated at our center between January 2016 and October 2020. We identified the total number of patients with SVT, and the number of patients with refractory SVT treated with Ivabradine. Similarly, we performed a thorough review of the databases of PubMed, Medline and Google Scholar to compare the clinical course of our patients to those described in the literature.

Results: Between January 2016 and October 2020, 79 pediatric patients with SVT were seen and treated at our center. A treatment-resistant SVT was noted only in three patients (4%). Ivabradine was used in these patients as a single or combined therapy. The rest (96%) were successfully treated with conventional anti-arrhythmics such as β-blockers, flecainide, and other approved medications. In the ivabradine group, successful reversal to sinus rhythm was achieved in two of the three patients (66%), one patient was treated with a combination therapy of amiodarone and ivabradine, and the other patient was treated only with ivabradine.

Conclusion: Overall, promissory results are associated with the use of ivabradine in pediatric patients with refractory SVT. Ivabradine appears to be a safe and well-tolerated medication that can induce adequate suppression of SVT, complete reversal to sinus rhythm, and effective enhancement of left ventricular function.

Ivabradine Versus Amiodarone in the Management of Postoperative Junctional Ectopic Tachycardia: A Randomized, Open-Label, Noninferiority Study

OBJECTIVES

This study sought to compare the efficacy of ivabradine and amiodarone in the management of postoperative junctional ectopic tachycardia (JET) after cardiac surgery in children.

BACKGROUND

JET is a serious arrhythmia occurring in children after cardiac surgery and requires aggressive management. Amiodarone has been conventionally used in its treatment. Recent studies have reported the utility of ivabradine in this regard.

METHODS

In this open-label randomized controlled trial, 94 children (age ≤18 years) who developed postoperative JET were allocated to receive either amiodarone or ivabradine. The primary endpoint was restoration of normal sinus rhythm.

RESULTS

Sinus rhythm was achieved in 43 out of the 46 patients (93.5%) in the amiodarone group and 46 out of the 48 patients (95.8%) in the ivabradine group (mean difference of treatment effect: 2.3%; 95% confidence interval: -6.7% to 11.5%). The median (interquartile range) time taken to achieve sinus rhythm conversion was similar in both the groups: 21.5 (17-30.2) hours versus 22 (13.4-38.5) hours (p = 0.36)]. The time taken to rate control of JET was significantly less in the amiodarone group: median 7.0 (5.5-9.5) hours versus 8.0 (5.8-10.8) hours (p = 0.02)]. No drug-related adverse events were observed in the ivabradine group.

CONCLUSIONS

Oral ivabradine is not inferior to intravenous amiodarone in converting postoperative JET to sinus rhythm. There was no difference in time taken to sinus rhythm conversion between the groups, although the rate control was earlier in patients who received amiodarone. Monotherapy with ivabradine may be considered as an alternative to amiodarone in the management of postoperative JET. (Comparison of Two Drugs, Ivabradine and Amiodarone, in the Management of Junctional Ectopic Tachycardia, an Abnormality in Cardiac Rhythm in Patients Under 18 years Who Undergo Cardiac Surgery: CTRI/2018/08/015182).

The bradycardic agent ivabradine decreases conduction velocity in the AV node and in the ventricles in-vivo

Ivabradine blocks hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels, thereby lowering the heart rate, an action that is used clinically for the treatment of heart failure and angina pectoris. We and others have shown previously that ivabradine, in addition to its HCN channel blocking activity, also inhibits voltage-gated Na channels in vitro at concentrations that may be clinically relevant. Such action may reduce conduction velocity in cardiac atria and ventricles. Here, we explore the effect of administration of ivabradine on parameters of ventricular conduction and repolarization in the surface ECG of anesthetized mice. We found that 5 min after i.p. administration of 10 mg/kg ivabradine spontaneous heart rate had declined by ~13%, which is within the range observed in human clinical studies. At the same time a significant increase in QRS duration by ~18% was observed, suggesting a reduction in ventricular conduction velocity. During transesophageal pacing at heart rates between 100 and 220 beats/min there was no obvious rate-dependence of ivabradine-induced QRS prolongation. On the other hand, ivabradine produced substantial rate-dependent slowing of AV nodal conduction. We conclude that ivabradine prolongs conduction in the AV-node and in the ventricles in vivo.

Use of ivabradine for treatment of junctional ectopic tachycardia in post congenital heart surgery

Cardiac surgeries especially involving crux of the heart as performed in tetralogy of Fallot (TOF) and pulmonary stenosis are mainly responsible for junctional ectopic tachycardia (JET). Diversified antiarrhythmic agents have been used in an impressive way to treat JET but showed suboptimal efficacy and varied associated adverse effects. But, ivabradine has proved as final crusader for its treatment. We report our initial experience of 4 cases in last 6 months with ivabradine in the management of postoperative JET. Encouraged by various reports and our increasing experience with ivabradine in heart failure population, we have moved to ivabradine as the first drug of choice for postoperative JET. Bradycardia was the only significant adverse effect in our series. The availability of atrial and ventricular pacing wires or at least transvenous temporary pacing should be ensured before starting ivabradine.