Expanding the Biophysical Insights Into Esophageal Heating During Radiofrequency Ablation

We would like to commend the authors for their important experimental work, which provides valuable biophysical insights into strategies to mitigate thermal esophageal injury during radiofrequency ablation (RFA) [1]. Although pulsed-field ablation has recently become the dominant modality for left atrial posterior wall ablation—with substantially reduced concern for esophageal complications—the biophysical mechanisms demonstrated in this study remain highly relevant, particularly for ventricular arrhythmia ablation where RFA continues to be widely used [2]. The authors elegantly show that esophageal heating is influenced by ablation power-time settings, the position of the dispersive return electrode, and the presence or absence of insulation around the esophageal temperature probe [1]. In particular, the finding that metallic esophageal probe components may themselves contribute to remote heating is a novel and clinically important observation. There are several points for which further experimental evaluation would deepen the scientific understanding of these mechanisms. The study compares high-power short-duration (HPSD) with low-power long-duration (LPLD) ablation [1]; however, these two settings differ in both power and time, making it difficult to isolate which parameter most strongly drives esophageal heating or lesion depth. A more comprehensive factorial design including HPLD and LPSD conditions would clarify whether excessive power delivery, prolonged duration, or the combined energy dose most critically influences thermal spread. In clinical practice, operators typically choose between HPSD and LPLD, but mechanistic separation of the two variables remains important to advance the field. Another important consideration is whether real-time impedance-based feedback could mitigate thermal injury. The DiamondTemp catheter, for example, adjusts ablation duration based on rapid tissue temperature changes transmitted through a diamond-embedded tip [3]. If such a system can detect early impedance decline—representing rapid resistive heating—it may terminate energy delivery before significant esophageal heating occurs. The extent to which impedance-based modulation can prevent the heating patterns demonstrated by the authors warrants further investigation. The implications of this study extend beyond atrial fibrillation. For ventricular tachycardia ablation, optimal placement of the return electrode is an unresolved but clinically meaningful issue. If deeper lesions are created when the target tissue lies directly between the ablation electrode and the dispersive patch, strategic anterior or lateral positioning may enhance lesion transmurality, particularly at challenging sites such as the LV summit or the lateral LV wall [4]. Conversely, it remains unknown whether non-insulated electrodes positioned in structures such as the coronary sinus could intentionally provide remote conductive enhancement similar to the esophageal probe phenomenon demonstrated here. These concepts have important implications for procedural efficacy and safety in ventricular substrates. The authors have nothing to report. The authors have nothing to report. The authors declare no conflicts of interest. The authors have nothing to report.