Initial Human Feasibility of Infusion Needle Catheter Ablation for Refractory Ventricular Tachycardia
Background—Ablation of ventricular tachycardia (VT) is sometimes unsuccessful when ablation lesions are of insufficient depth to reach arrhythmogenic substrate. We report the initial experience utilizing a catheter with an extendable/retractable irrigated needle at the tip capable of intramyocardial mapping and ablation.
Methods and Results—Sequential consenting patients with recurrent VT underwent ablation using a needle-tipped catheter. At target sites the needle was advanced 7-9 mm into the myocardium, permitting pacing and recording. Infusion of saline/iodinated contrast mixture excluded perforation and ensured intramyocardial deployment. Further infusion was delivered before and during temperature-controlled radiofrequency energy delivery through the needle. All 8 patients included (6 male, mean age 54) with mean LVEF 29% were refractory to multiple antiarrhythmic drugs and had failed 1-4 prior catheter ablation attempts (epicardial in 4). Patients had 1-7 (median 2) VTs present or inducible; 2 incessant. Some intramyocardial VT mapping was possible in 7 patients. A mean of 22 (limits 3-48) needle ablation lesions were applied in 8 patients. All patients had at least 1 VT terminated or rendered noninducible. During a median of 12 months follow-up, 4 were free of recurrent VT, and 3 were improved, but had new VTs occur at some point during follow-up. Two died of progression of preexisting heart failure without recurrent VT. Complications included tamponade in 1 and heart block in 2 patients.
Conclusions—Intramyocardial infusion-needle catheter ablation is feasible and permits control of some VTs that have been refractory to conventional catheter ablation therapy, warranting further study.
- Intramyocardial Ablation
- needle ablation
- catheter ablation
- ventricular tachycardia
- intramural reentry
- Received May 9, 2013.
- Revision received June 29, 2013.
- Accepted August 12, 2013.