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Europace : European Pacing,... Nov 2022While mexiletine has been used for over 40 years for prevention of (recurrent) ventricular arrhythmias and for myotonia, patient access has recently been critically...
AIMS
While mexiletine has been used for over 40 years for prevention of (recurrent) ventricular arrhythmias and for myotonia, patient access has recently been critically endangered. Here we aim to demonstrate the effectiveness and safety of mexiletine in the treatment of patients with (recurrent) ventricular arrhythmias, emphasizing the absolute necessity of its accessibility.
METHODS AND RESULTS
Studies were included in this systematic review (PROSPERO, CRD42020213434) if the efficacy or safety of mexiletine in any dose was evaluated in patients at risk for (recurrent) ventricular arrhythmias with or without comparison with alternative treatments (e.g. placebo). A systematic search was performed in Ovid MEDLINE, Embase, and in the clinical trial registry databases ClinicalTrials.gov and ICTRP. Risk of bias were assessed and tailored to the different study designs. Large heterogeneity in study designs and outcome measures prompted a narrative synthesis approach. In total, 221 studies were included reporting on 8970 patients treated with mexiletine. Age ranged from 0 to 88 years. A decrease in ventricular arrhythmias of >50% was observed in 72% of the studies for pre-mature ventricular complexes, 64% for ventricular tachycardia, and 33% for ventricular fibrillation. Electrocardiographic effects of mexiletine were small; only in a subset of patients with primary arrhythmia syndromes, a relative (desired) QTc decrease was reproducibly observed. As for adverse events, gastrointestinal complaints were most frequently observed (33% of the patients).
CONCLUSIONS
In this systematic review, we present all the currently available knowledge of mexiletine in patients at risk for (recurrent) ventricular arrhythmias and show that mexiletine is both effective and safe.
Topics: Humans; Infant, Newborn; Infant; Child, Preschool; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Mexiletine; Arrhythmias, Cardiac; Ventricular Fibrillation; Electrocardiography; Heart Ventricles
PubMed: 36036670
DOI: 10.1093/europace/euac087 -
Frontiers in Cardiovascular Medicine 2022Brugada syndrome (BrS) is associated with ventricular tachyarrhythmias. However, the presence of electrical strom (ES) and its management still debated.
BACKGROUND
Brugada syndrome (BrS) is associated with ventricular tachyarrhythmias. However, the presence of electrical strom (ES) and its management still debated.
OBJECTIVES
We present the outcome and management of 44 BrS patients suffering from ES.
METHODS
A systematic literature review and pooled analysis Through database review including PubMed, Web of Science, Cochrane Libary and Cinahl studies were analyzed. Evidence from 7 reports of 808 BrS patients was identified.
RESULTS
The mean age of patients suffering from ES was 34 ± 9.5 months (94.7% males, 65.8% spontaneous BrS type I). Using electrophysiological study ventricular tachycardia/ventricular fibrillation were inducible in 12/23 (52.2%). Recurrence of ES was documented in 6.1%. Death from ES was 8.2% after a follow-up of 83.5 ± 53.4. In up to 27 ES resolved without treatment. External shock was required in 35.6%, internal ICD shock in 13.3%, Overdrive pacing, left cardiac sympathetic block and atropin in 2.2%. Short-term antiarrhythmic management was as the following: Isopreterenol or Isopreterenol in combination with quinidine 35.5%, orciprenaline in 2.2%, quinidine 2.2%, disopyramide 2.2% or denopamide 2.2%. However, lidocaine, magensium sulfate, mexiletine and propanolol failed to control ES.
CONCLUSION
Although ES is rare in BrS, this entity challenges physicians. Despite its high mortality rate, spontaneous termination is possible. Short-term management using Isoproterenol and/or quinidine might be safe. Prospective studies on management of ES are warranted.
PubMed: 36386327
DOI: 10.3389/fcvm.2022.981715 -
Journal of Neuromuscular Diseases 2021Skeletal muscle ion channelopathies include non-dystrophic myotonias (NDM), periodic paralyses (PP), congenital myasthenic syndrome, and recently identified congenital...
BACKGROUND
Skeletal muscle ion channelopathies include non-dystrophic myotonias (NDM), periodic paralyses (PP), congenital myasthenic syndrome, and recently identified congenital myopathies. The treatment of these diseases is mainly symptomatic, aimed at reducing muscle excitability in NDM or modifying triggers of attacks in PP.
OBJECTIVE
This systematic review collected the evidences regarding effects of pharmacological treatment on muscle ion channelopathies, focusing on the possible link between treatments and genetic background.
METHODS
We searched databases for randomized clinical trials (RCT) and other human studies reporting pharmacological treatments. Preclinical studies were considered to gain further information regarding mutation-dependent drug effects. All steps were performed by two independent investigators, while two others critically reviewed the entire process.
RESULTS
For NMD, RCT showed therapeutic benefits of mexiletine and lamotrigine, while other human studies suggest some efficacy of various sodium channel blockers and of the carbonic anhydrase inhibitor (CAI) acetazolamide. Preclinical studies suggest that mutations may alter sensitivity of the channel to sodium channel blockers in vitro, which has been translated to humans in some cases. For hyperkalemic and hypokalemic PP, RCT showed efficacy of the CAI dichlorphenamide in preventing paralysis. However, hypokalemic PP patients carrying sodium channel mutations may have fewer benefits from CAI compared to those carrying calcium channel mutations. Few data are available for treatment of congenital myopathies.
CONCLUSIONS
These studies provided limited information about the response to treatments of individual mutations or groups of mutations. A major effort is needed to perform human studies for designing a mutation-driven precision medicine in muscle ion channelopathies.
Topics: Channelopathies; Humans; Hypokalemic Periodic Paralysis; Lamotrigine; Mexiletine; Muscle, Skeletal; Mutation; Myasthenic Syndromes, Congenital; Myotonic Disorders; Precision Medicine; Randomized Controlled Trials as Topic; Sodium Channel Blockers
PubMed: 33325393
DOI: 10.3233/JND-200582