Catheter ablation is the established first-line therapy for symptomatic supraventricular tachycardia, and current ESC guidelines1 endorse it without specifying a preferred energy source, leaving the choice between radiofrequency (RF) and cryoablation to operator discretion. For most substrates, RF ablation has set a robust benchmark: high acute success, low recurrence, and an acceptable complication profile.2 However, in the region of the atrioventricular (AV) node and His bundle, even routine lesions carry a risk of irreversible AV block and the need for permanent pacing, underscoring the importance of careful risk assessment.3

The experience reported in this issue by Bernardo et al.,4 from a Portuguese tertiary center, addresses this tension directly. In a deliberately selected, anatomically high-risk cohort comprising AV node reentry tachycardia (AVNRT) and predominantly para-Hisian accessory pathways (APs), cryoablation achieved a 100% acute success rate in AVNRT and 77% in septal APs, with no cases of permanent AV block. Transient conduction disturbances occurred but resolved promptly upon energy interruption: a well-recognised advantage of the cryoenergy platform. These results are consistent with published data showing that cryoablation can achieve efficacy comparable to RF in perinodal substrates while substantially reducing the risk of permanent conduction injury, at the cost of somewhat higher recurrence rates.5–7

Two aspects of the series merit particular attention. First, operators accepted lower acute success rates in electrophysiologically low-risk para-Hisian pathways in oligosymptomatic patients, rather than escalate energy delivery toward the threshold of AV block. This reflects a reasonable clinical trade-off: when tachycardia burden is modest and the pathway's intrinsic refractory period renders dangerous arrhythmias unlikely, the risk–benefit calculus may not favour aggressive ablation regardless of energy source. Second, all patients with prior unsuccessful RF ablation achieved acute success with cryoenergy and remained recurrence-free during follow-up: a finding that, while based on small numbers, suggests that cryoenergy may offer advantages in this setting. Mechanistically, cryoadhesion stabilises catheter contact and reversible cryomapping allows confirmation of target accuracy before committing to a permanent lesion, potentially converting anatomically difficult substrates into more controlled applications.5,6

The temporal trends documented in this series are also instructive when contextualising historical recurrence data. Outcomes improved substantially after 2016, coinciding with the routine adoption of 6-mm cryocatheters and three-dimensional electroanatomical mapping. AP acute success rose from 50% to 95%, and fluoroscopy was eliminated in almost 40% of later procedures. Much of the legacy concern about higher cryoablation recurrence stems from series using smaller catheters and limited mapping; contemporary multicentre data with 6–8 mm tips report acute success and recurrence increasingly close to RF in AVNRT and septal substrates, while preserving cryo's superior safety margin.7

The series also draws attention to an underexplored subgroup: older patients with baseline conduction system abnormalities, including first-degree AV block, bundle branch block, and bifascicular block. In this population, the risk of complete AV block with RF ablation is a recognised concern, and the reversibility of cryomapping offers a particularly relevant safety margin.3 The outcomes reported here are reassuring, but the numbers are small, and this observation requires prospective validation before it can inform formal decision algorithms. That said, it broadens the potential patient population that may benefit from a safety-first energy strategy beyond the traditionally younger cohort.

For clinical practice, the available evidence, including the present series, supports considering cryoablation as a primary strategy, rather than solely a fallback, in well-defined high-risk anatomical settings: young patients, para-Hisian and mid-septal APs, atypical AVNRT, and individuals with pre-existing conduction disease.4–9 RF ablation remains appropriate for left-sided or non-septal substrates and where rapid, definitive elimination is the overriding priority. The key advantage of cryoenergy near the AV node is not that it achieves higher efficacy, but that it allows the operator to test before committing: a property that matters most precisely where the consequences of an unintended lesion are most severe.5–9

Several research questions remain open. Whether baseline conduction disease should formally enter decision algorithms for energy-source selection is unanswered. Prospective, multicentre comparisons focused specifically on septal and para-Hisian substrates, stratified by age, conduction status, and pathway electrophysiological risk, would help clarify the clinical scenarios in which RF's modest efficacy advantage truly justifies its higher risk of permanent AV block. Until such evidence is available, the data from Bernardo et al.4 support a measured but reasoned expansion of cryoablation use in the perinodal region. Where the margin for error is narrowest, the ability to map before committing is not a luxury– it is sound procedural logic.5,9 In this context, it is worth noting that the growing enthusiasm for new energies, however promising, should not prematurely displace a technology with a well-established safety record in the perinodal space. Until alternatives demonstrate comparable safety in this setting, focal cryoablation remains an important option.