Catheter Ablation Of Ventricular Arrhythmias Research Articles

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

New insights in catheter ablation of ventricular arrhythmia

Expanding Role of Catheter Ablation for Ventricular Arrhythmias

Recently, patients with idiopathic ventricular fibrillation (VF) were treated successfully with catheter ablation, targeted at premature ventricular contractions (PVCs) that arose from the right ventricular outflow tract (RVOT) or from the Purkinje system ( Circulation 2002; 106:962). Now, researchers have performed similar mapping and ablation in 4 patients with the long-QT syndrome (LQTS) and 3 with …

Laser catheter coagulation of normal and scarred ventricular myocardium in dogs.

Larger lesions would increase success rates of catheter ablation of ventricular arrhythmias. Therefore, improved radio frequency current application techniques, but also alternative energy sources, are being investigated. The purpose of this study was to determine morphology and dimensions of ventricular lesions induced by transcatheter application of laser energy. A total of 244 lesions were produced by Nd:YAG laser pulses, 1,064 nm, 10-30 W, 15-60 s, percutaneously (endocardial approach, n = 124) and under visual control (epicardial approach, n = 120) in the left ventricular walls of 24 anesthetized dogs. Dimensions of lesions increased with the amount of energy applied. Maximal values were obtained at 20 W, 60 s: depth = 12.6 +/- 1.1 mm (transmural); width = 15.0 +/- 2.8 mm; volume = 1,582 +/- 777 mm3. Volumes of lesions did not change significantly when induced through previously scarred myocardium. Histologically, lesions were clear-cut, without crater or thrombus formation. Procedures and follow-up periods of up to 22 months were without complications. Nd:YAG laser pulses at 10-20 W and 15-60 s produce homogeneous myocardial lesions of coagulation necrosis of reproducible sizes, in a controllable manner, without unwanted effects on the ventricular walls, in normal and through scarred myocardium of dogs. The laser method is a promising alternative for ablation of ventricular arrhythmias including candidates with ischemic heart disease.

Effects of combined radiofrequency and direct current energy catheter ablation on ventricular myocardium in pigs

When radiofrequency catheter ablation of ventricular arrhythmias is unsuccessful, an option may be to combine it with direct current energy. We therefore investigated the effects of such a combination. Radiofrequency energy was delivered in a bipolar or unipolar fashion to the left and right ventricles through an ablation catheter with a tip electrode 2 mm long, using a temperature-guided radiofrequency generator. Radiofrequency ablation was followed by a single cathodal direct current shock (66 J) with the ablation catheter positioned similarly in six closed-chest pigs. In a control group (six animals) only direct current ablation was performed, with one or two energy applications (66 J) in each ventricle. Two of six animals in the radiofrequency/direct current group died due to perforation in the follow-up period, 1 and 3.5 h after the direct current ablation, respectively. Gross pathological examination of the hearts revealed transmural lesions in all animals. In the radiofrequency/direct current group four lesions were perforated, three of which were located in the left ventricle. There was a significant increase in the number of perforations in the radiofrequency/direct current group compared to the control group, where perforation was never observed. Haemorrhagic pericardial fluid was found in five of the six animals in the radiofrequency/direct current group compared to none in the control group. These findings show that myocardial ablation with radiofrequency energy followed by direct current energy in the same session may have a high complication rate.

Representation of cardiac electrical activity by a moving dipole for normal and ectopic beats in the intact dog.

Representation of cardiac electrical activity by a moving dipole for normal and ectopic beats in the intact dog.