Needle-Timed Catheter Ablation of Papillary Muscle Results in Deeper and Larger Ablation Lesions

Ventricular tachycardia associated with papillary muscle (PM) is often refractory to standard radiofrequency ablation (RFA). The needle-tipped ablation catheter (NT-AC) has been used to treat deep intramyocardial substrates, but its use for PM has not been characterized. Using an ex vivo experimental platform, both 3 mm and 6 mm NT-AC created larger ablation lesion volumes and depths than open-irrigated ablation catheter did (OI-AC; e.g., 57.12+ 9.70mm(3) and 2.42+0.22 mm, respectively; p < 0.01 for all comparisons). Longer NT-AC extension (6 mm) resulted in greater ablation lesion volumes and maximum depths (e.g., 333.14 +29.13mm(3) and 6.46 + 0.29 mm, respectively, compared to the shorter 3 mm NT-AC extension, 143.33 +/- 12.77mm(3), and 4.46 +/- 0.14 mm; both p < 0.001). There were no steam pops. In conclusion, for PM ablation, the NT-AC was able to achieve ablation lesions that were larger and deeper than with conventional OI-AC. Ablation of PM may be another application for needle-tip ablation. Further studies are warranted to establish long-term safety and efficacy in human studies.

Automated summary

Research found that the needle-tipped ablation catheter (NT-AC) could create larger and deeper ablation lesions in papillary muscle ablation compared to the traditional open-irrigated ablation catheter (OI-AC). This may be another potential application for needle-tip ablation. Further studies are necessary to establish long-term safety and efficacy in human subjects.