Use of a saline-irrigated tip catheter for ablation of ventricular tachycardia resistant to conventional radiofrequency ablation: early experience.
BACKGROUND
Radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) may fail if the critical isthmus is located intramyocardially or epicardially. The design of a saline-irrigated tip (SIT) catheter (Thermo-Cool, Cordis-Webster) involves active cooling of the tip electrode, which allows creation of larger ablation lesions.


RESULTS
Eight patients (6 men, age 59 +/- 12 years) in whom the clinical target VT (cycle length 430 +/- 97 msec) could not be ablated using a conventional 4-mm tip RF ablation catheter underwent additional attempts to ablate this VT using a SIT catheter. Six patients had an old myocardial infarction, 1 patient had a dilated cardiomyopathy, and 1 patient had a structurally normal heart. Ablation of the clinical target VT using a SIT catheter was attempted from the left ventricle in 6 (septal, posterobasal, and inferior: 2 each) and from the right ventricle in 2 patients (both septal), by entrainment (n = 6), activation (n = 1), or pace mapping (n = 1). A mean of 6 +/- 5 (range 2 to 15) pulses were delivered. Target VT ablation was successful in 5 patients (63%). After successful ablation, at a mean follow-up of 6.5 +/- 4 months and while taking antiarrhythmic drugs, all 5 patients were free of VT recurrences.


CONCLUSIONS
The clinical target VT could be ablated using a SIT catheter in 5 (63%) of the 8 patients in whom ablation using a conventional RF catheter was unsuccessful. In the 2 patients with septal VT, a biventricular approach to mapping and ablation was required.
Nabar
A
A
Department of Cardiology, Academic Hospital Maastricht, The Netherlands.
Rodriguez
L M
LM
Timmermans
C
C
Wellens
H J
HJ
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation*; D017097:Electric Impedance; D004562:Electrocardiography; D004566:Electrodes; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012965:Sodium Chloride; D017180:Tachycardia, Ventricular / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*
D000889:Anti-Arrhythmia Agents; D012965:Sodium Chloride