To the Editor- Bipolar ablation of refractory VT circuits: Current opportunities and limitations.

We’ve read with great interest the article by Al-Hadithi and colleagues dealing with unstable ventricular tachycardia (VT) treated with bipolar radiofrequency catheter ablation (Bi-RFCA). We find this case a good opportunity for further discussion on Bi-RFCA.

The authors mentioned that the left ventricular summit (LVS) is a challenging location of VT. Bi-RFCA was already utilized for ablation of LVS. We’ve found that LVS Bi-RFCA between coronary veins and adjacent left ventricular sites is feasible and effective. Currently we treated with this technique 4 patients with good long-term results (submitted for publication). For arrhythmias originating from the inaccessible LVS, Bi-RFCA targeting the left pulmonary cusp can be considered.

The authors achieved success using moderate powers (40 W). Sometimes high-power values are required; however, the safety cut-off for Bi-RFCA remains unknown. One in vitro study brings also some important suggestions regarding steam pops, which did not occur only when an 8-mm-tip catheter was used as a return electrode (RE). Recently we reported an incidental temperature rise of 4-mm-tip RE. These findings may suggest a better safety profile of an 8 mm catheter used as RE.

The presented case shows that extracorporeal membrane oxygenation–supported Bi-RFCA can also be feasible in patients with hemodynamically unstable VT. The fact that VT abolition was achieved using moderate power can additionally encourage the use of this approach for the treatment of some resistant midmyocardial VT circuits.