Pharmacotherapy in inherited and acquired ventricular arrhythmia in structurally normal adult hearts

ABSTRACT

Introduction: Ventricular arrhythmias are often seen in association with structural heart disease. However, approximately a tenth of affected patients have apparently normal hearts, where such arrhythmias typically occur in young patients, are sometimes inherited and can occasionally lead to sudden cardiac death (SCD). Over the past two decades, increased understanding of the underlying pathophysiology resulted in improved targeted pharmacological therapy.

Areas covered: This article reviews current knowledge regarding drug therapy for inherited arrhythmia syndromes (Brugada, early repolarization, long QT and short QT syndromes, and catecholaminergic polymorphic ventricular tachycardia), and acquired arrhythmias (idiopathic ventricular fibrillation, short-coupled torsade de pointes, outflow tract ventricular tachycardia, idiopathic left, papillary muscle and annular ventricular tachycardias).

Expert opinion: In inherited arrhythmia syndromes, appropriate clinical and genetic diagnoses followed by proper selection and dosing of antiarrhythmic drugs are of utmost importance to prevent SCD, most often without the need of implantable cardioverter-defibrillators. In acquired arrhythmias, appropriate pharmacotherapy in selected patients can also provide symptomatic relief and avoid the need for invasive therapy. Further research is needed to develop novel antiarrhythmic drugs or targeted therapy to increase efficacy and limit side effects.

KEYWORDS:

• Antiarrhythmic drugs
• inherited arrhythmia syndrome
• idiopathic ventricular tachycardia
• sudden cardiac death
• long QT syndrome
• brugada syndrome
• catecholaminergic polymorphic ventricular tachycardia
• idiopathic ventricular fibrillation

Article highlights

• Pharmacotherapy of Brugada syndrome is limited. Quinidine has been shown to be beneficial. Isoproterenol perfusion is useful in arrhythmic storm. Avoidance of sodium-channel blockers is recommended (www.brugadadrugs.org).

• Pharmacotherapy is the cornerstone of long QT syndrome therapy and defibrillator implantation is seldom needed. Beta-blockers are indicated in all patients. Mexilitine can be added in long QT type 3 and possibly also other subtypes. Sympathetic denervation may be of benefit in high risk patients. Avoidance of QT prolonging drugs is recommended (www.crediblemeds.org).

• Catecholaminergic polymorphic ventricular tachycardia is highly malignant but pharmacotherapy is very effective and defibrillator implantation is rarely needed. Beta-blockers are the treatment cornerstone and flecainide offers additional benefit. Sympathetic denervation may be of benefit in high risk patients.

• Idiopathic ventricular fibrillation and early repolarization syndrome can be treated with quinidine. Isoproterenol perfusion is useful in arrhythmic storm.

• Idiopathic monomorphic ventricular tachycardia has an excellent prognosis. Symptomatic relief is accomplished using beta-blockers, calcium-channel blockers or flecainide. Catheter ablation is highly effective and safe and should be performed in patients where pharmacotherapy is either ineffective or non-tolerated.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

Dr S. Ortmans has received research grant support from the Fédération Française de Cardiologie while Dr R. Tadros is supported by the Philippa and Marvin Carsley Cardiology Chair and is currently a clinical research scholar of the Fonds de Recherche du Québec – Santé.