BACKGROUND

Monomorphic tachycardia with an epicardial site of the arrhythmic focus in the left ventricular outflow tract (LVOT) usually cannot be ablated by an endocardial approach. We describe the use of cooled tip catheter ablation through the aortic sinus of valsalva to treat LVOT tachycardia.

METHODS

In seven patients (four males, one with valvular cardiomyopathy, six patients without heart disease) with sustained and non-sustained ventricular tachycardia (VT) an epicardial focus of LVOT tachycardia could be identified by pace-mapping and earliest local activation within the aortic sinus of valsalva. Coronary angiography served to define the position of the coronary arteries with respect to the ablation catheter. High frequency current was delivered using a closed-loop cooled tip catheter system (Chilli Cool(R), Boston Scientific). ECG, Holter-ECG, echocardiography and transesophageal echocardiography were performed after the procedure and 3 months later.

RESULTS

Foci were located in the left (two patients), in the right (three) and in the a coronary aortic sinus (two). Successful ablation could be achieved in six patients. No procedure-related complications could be observed during a mean follow-up of 4.2 months.

CONCLUSION

Monomorphic VT with epicardial origin in the LVOT can be successfully treated by cooled tip ablation through the aortic sinus of valsalva. The use of a cooled tip ablation system may be favourable in several ways: 1) it allows the creation of deep lesions necessary to reach remote foci; 2) due to lower temperatures at the catheter/tissue interface surface tissue damage may be reduced; 3) lower catheter temperature may additionally reduce the risk of local clot formation which is crucial for all left-sided procedures and especially for ablation in the sinus of valsalva.