October 2019 | Issue 46
ESC guidelines on supraventricular tachycardias underline the pivotal role of catheter ablation therapy The European Society of Cardiology unveiled guidelines for treatment of supraventricular tachycardia (SVT) on the opening day of its Congress (ESC 2019; 31 August–4 September, Paris, France). Simultaneously published online in the European Heart Journal, the document provides recommendations for all types of SVT, and cements the role of catheter ablation therapy, with a press release from the ESC describing it as “revolutionising care”.
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he consensus document is based on an up-todate review of the evidence, and summarises the latest developments and advances since the last ESC guidelines on SVTs in 2003, as well as areas for further research. Although drug therapies for SVTs have not fundamentally changed in the past 16 years, the availability of catheter ablation has led to major changes in clinical practice. The guidelines provide general recommendations for the management of adults with SVT based on the principles of evidence-based medicine, but the authors point out that, because evidence and expert opinions from several countries are included, some antiarrhythmic approaches may not have the approval of governmental regulatory agencies in all countries. In addition, many of the drugs that were recommended previously have not been considered in the 2019 guidelines. Professor Demosthenes Katritsis (Hygeia Hospital, Athens, Greece) is a chairperson of the guidelines taskforce. In the press release, he points out: “Catheter ablation techniques and technology have evolved in a way that we can now offer this treatment modality to most of our patients with SVT.” SVTs have a prevalence of approximately 0.2% in the general population, and women are at twice the risk of men, with those aged ≥65 years at more than five times the risk of younger people. If left untreated, SVTs increase the risk of stroke and affect quality of life. Antiarrhythmic drugs are useful for acute episodes, but have limited value for long-term use, due to relatively low efficacy and related side-effects. Among the concepts that have been revised in the updated guidance are: ■ Drug therapy for inappropriate sinus tachycardia and focal atrial tachycardia ■ Therapeutic options for acute conversion and anticoagulation of atrial flutter ■ Therapy of atrioventricular nodal re-entrant tachycardia (AVNRT) ■ Therapy of antidromic AVNRT and pre-excited atrial fibrillation Josep Brugada, co-chairperson of the guidelines taskforce
■ Management of patients with asymptomatic preexcitation ■ Diagnosis and therapy of tachycardiomyopathy. SVT is linked with a higher risk of complications during pregnancy, and specific recommendations are provided for pregnant women. All antiarrhythmic drugs should be avoided, if possible, within the first trimester of pregnancy. However, if necessary, some drugs may be used with caution during that period. The guidelines also suggest that, if ablation is necessary during pregnancy, non-fluoroscopic mapping may be used. “Pregnant women with persistent arrhythmias that do not respond to drugs, or for whom drug therapy is contraindicated or not desirable, can now be treated with catheter ablation using new techniques that avoid exposing themselves or their baby to harmful levels of radiation,” says Katritsis. The recommendations provide some key messages. These include: ■ Vagal manoeuvres and adenosine are the treatments of choice for the acute therapy of SVT, and may also provide important diagnostic information ■ Verapamil is not recommended in wide QRScomplex tachycardia of unknown aetiology ■ In all re-entrant and most focal arrhythmias, catheter ablation should be offered as an initial choice to patients, after having explained in detail the potential risks and benefits ■ Patients with macro re-entrant tachycardias following atrial surgery should be referred to specialised centres for ablation ■ In post-atrial fibrillation (AF) ablation atrial tachycardias (ATs), focal or macro re-entrant, ablation should be deferred for three or more months after AF ablation, when possible ■ Ablate AVNRT, typical or atypical, with lesions in the anatomical area of the nodal extensions, either from the right or left septum ■ AVNRT, typical or atypical, can now Continued on page 2
Jenny Bjerre:
Driving and ICDs
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Pedro Brugada:
Profile
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Cynthia James:
Risk prediction model Page 12
Maximum-fixed energy shocks are more effective than low-escalating energy shocks for cardioverting AF
A study that compared the use of maximum-fixed energy and low-escalating energy shocks for cardioversion in patients with atrial fibrillation (AF) found that maximum-fixed shocks were significantly more effective at cardioverting AF. No differences were found in any safety endpoints included in the study between patients treated with either method. RESULTS FROM THE study were presented by Anders Sjoerslev Schmidt (Randers Regional Hospital, Randers; Aarhus University, and Aarhus University Hospital, Denmark) in a Hotline Session at the European Society of Cardiology Congress (ESC 2019; 31 August–4 September, Paris, France). He stated: “We found that when using maximumfixed shocks the cardioversion efficacy was 88%, compared to 66% when using a more standard low-escalating approach. This was a 22% absolute difference and statistically significant.” Direct-current cardioversion of AF is one of the most commonly performed clinical procedures in cardiology, emergency, and critical care medicine. However, the 2016 ESC guidelines on the management of AF do not specify which energy levels to use when performing the procedure. Schmidt explained: “It is common practice to use low initial energy shocks with escalating effect, if necessary. This protocol was originally introduced to improve safety in the era of monophasic shocks. Now we more commonly use biphasic shocks for cardioversion, which are more effective than monophasic shocks, and safer in terms of not Continued on page 2