Irrigated Tip Catheters for Radiofrequency Ablation in Ventricular Tachycardia (original) (raw)
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Journal of Cardiovascular Electrophysiology, 1999
Saline-Irrigated RF Catheter Ablation. Introduction: In animal models, active cooling of the electrode during radiofrequency (RF) ablation allows creation of larger lesions, presumably by increasing the power that can be delivered without coagulum formation. These RF lesions have not been characterized in human myocardium in regions of infarction and scarring.Methods and Results: Cooled-tip RF catheter ablation of ventricular tacbycardias (VTs) was performed in two patients who had severe congestive heart failure and subsequently underwent cardiac transplantation. The first patient bad four different monomorphic VTs. RF applications along the inferoseptal margin of a scarred region abolished all inducible VTs. The second patient had sarcoidosis involving the myocardium and four different inducible VTs. RF current applied at an inferobasal VT exit and at the right and left septa failed to abolish the VTs. The explanted hearts were examined at the time of cardiac transplantation 18 and 21 days later, respectively. Lesions extended to depths up to 7 mm, reaching clusters of myocardial cells deep to regions of fibrosis. Microscopically, the ablation sites contained coagulation necrosis with hemorrhage, surrounded by a rim of granulation tissue.Conclusion: Saline-irrigated RF catheter ablation produces relatively large lesions capable of penetrating deep into scarred myocardium.
The Role of Radiofrequency Catheter Ablation in the Treatment of Nonischemic Ventricular Tachycardia
SUMMARY ñ Radiofrequency catheter ablation can be used for the treatment of different patient groups with nonischemic ventricular tachycardia (VT). Concerning the small area of induced ventricular injury, a high degree success is expected in patients with idiopathic VT and in patients with bundle branch reen- trant VT. The long-term success rate of radiofrequency ablation in the cure of idiopathic VT and bundle branch reentrant VT is about 90% and 100%, respectively. Radiofrequency ablation of VT in arrhythmogen- ic right ventricular dysplasia (ARVD) can be effective in patients with localized disease and single VT origin. In patients with more extensive ARVD and/or pleomorphic VT, other therapeutic options should be considered. In patients with idiopathic dilated cardiomyopathy, radiofrequency ablation is not curative but may be used as an adjunctive therapy to reduce the frequency and severity of VT. By using the new mapping systems, the application of radiofrequency ablation is e...