Effects of mult ipolar electrode radiofrequency energy delivery on vent r icu lar endocardium
- M Oeff, JJ Langberg, JO Frankl in
- Am Heart J
Cardiac arrhythmias can be treated by endocardial laser photocoagulation of arrhythmogenic foci. Transcatheter continuous wave Nd-YAG laser (1064 nm) photocoagulation was studied for impairment of atrioventricular (AV) conduction. First, studies on the dose-effect relation revealed that in vitro applications to ventricular endocardium produce dose-dependent coagulation necrosis. However, energy absorption varies in tissue specimens from different experimental animals and humans and may be dependent on differences in surfaces ultrastructure. Ten times more energy is required for human endocardial specimens than for canine endocardium. The long-term in vivo experiment demonstrates that the chronic laser-induced myocardial lesion size is proportional to the applied energy, exhibit no arrhythmogenic effects and may thus be suitable for the treatment of cardiac arrhythmias. Transcatheter laser application using a combined electrode-laser catheter reliably achieved a slowing of atrioventricular AV conduction (AV modification) or a complete AV block. Thus, the transcatheter application of Nd-YAG laser energy at the AV node may be useful for treatment of tachyarrhythmias in man.