1.0 Introduction
CA with either radiofrequency (RF) energy or cryoenergy is a well-establish therapy in treating SVT in both paediatric and adult populations [1]. Traditionally, X-ray fluoroscopy is used during CA procedures, though the utilisation of ionising radiation carries non-negligible stochastic and deterministic risks to the health of both the patient and the professional staff. These effects are cumulative and behave in a linear no-threshold manner and, as such, are especially important in paediatric populations [2]. The importance of reducing ionising radiation exposure has been recognised by the American College of Cardiology, which recommends the ALARA (as low as reasonably achievable) principle in all interventional laboratories [3].
In recent years, advances in three-dimensional (3D) electroanatomical mapping (EAM) systems and their utilisation have enabled the near-zero and ZF approaches to be studied. In a recent multicentre randomised trial investigating the near-zero approach in right- and left-sided SVT ablation, reduction of fluoroscopy was achievable in all patients and resulted in an estimated 96% reduction in overall risk of cancer incidence and mortality. The study also estimated that the supplementary cost associated with the addition of the 3D EAM system is justified when increase in life expectancy and period of life without cancer are considered [4]. However, most data regarding the feasibility, safety, and efficacy of the ZF approach is available for right-sided SVT only [5–8].
The aim of this study was to evaluate the safety and efficacy of ZF CA for the treatment of SVTs in adult and paediatric populations in comparison to the CF-based approach.