Radiofrequency ablation (RFA) is a pivotal therapeutic technique for various medical conditions, including cardiovascular disease and oncological conditions such as liver and lung cancer. The energy-controlled mode in RFA procedures allows for uniform energy delivery but is less safe compared to the temperature-controlled mode. Therefore, it is necessary to develop a protocol that ensures safety while efficiently delivering energy in the temperature-controlled mode. In this study, we compared lesion formation using the gradual-temperature-rise mode to the fixed-temperature mode. We evaluated the lesion size, energy, cumulative time efficiency, and procedural safety in both in vitro and in vivo experiments with porcine myocardial tissue. Three experimental groups (n = 6) were compared to assess the effect of gradual-temperature-rise and fixed-temperature ablation modes. Five experimental groups (n = 6) were used to determine the optimal temperature turn-up time. The gradual-temperature-rise mode ablated larger lesions (10.48 ± 0.56 mm) compared to the 75 °C (7.67 ± 0.37 mm) and 85 °C (8.05 ± 0.36 mm) fixed-temperature groups (p = 0.002). The optimal turn-up time for efficient lesion formation was found to be between 120 and 180 s. The in vivo experiments validated the safety and efficacy of the optimized gradual-temperature-rise mode. Therefore, using the gradual-temperature-rise mode of temperature-controlled RFA enhances lesion formation, energy transfer, and safety, making it a promising approach for clinical application in cardiac ablation procedures.

Background: Current treatments for hypertrophic obstructive cardiomyopathy (HOCM), including medication, surgery, and alcohol septal ablation (ASA), have limitations in terms of efficacy and safety. To address these challenges, we developed the trans-coronary intra-septal radiofrequency ablation (TIRA) device. Methods: This first-in-human trial was conducted to assess the efficacy and safety of the TIRA device. Moreover, evaluations were conducted before the procedure and at 3, 6, and 12 months post-procedure using computed tomography, magnetic resonance imaging, echocardiography, and the 6 min walk distance (6MWD) test. Results: Four patients were enrolled, and follow-up imaging at 3, 6, and 12 months showed a reduction in the interventricular septal (IVS) thickness (baseline mean: 22.6 mm; 12-month mean: 18.9 mm) and a decrease in the LVOT pressure gradient at 12 months (resting baseline mean: 84.64 mmHg; resting 12-month mean: 43.56 mmHg; Valsalva baseline mean: 129.96 mmHg; Valsalva 12-month mean: 108.16 mmHg). However, reductions in the IVS thickness on echocardiography and improvements in 6MWD were observed in only two patients. Conclusions: No significant adverse events, such as arrhythmias or vascular injuries, were reported. These findings suggest that the TIRA device may be a safe and effective option for treating HOCM. However, further studies are required to confirm these results.