Effects of catheter-delivered electrical discharges near the tricuspid anulus in XXXX .

@entity32 @entity1165 @entity39 @entity235 @entity713 @entity340 @entity943
The possibility of using electrical discharges to ablate right free wall accessory pathways by delivering a series of catheter shocks near the tricuspid anulus was assessed in a @entity235 model. Before the shock, the amplitudes of the atrial and ventricular electrograms recorded from the distal electrodes were compared (A/V ratio), and the atrial pacing threshold was determined. To assess effects on function and arrhythmogenicity, right heart pressures were measured and programmed ventricular stimulation was performed before the shock and prior to sacrifice 7 to 10 days after the shock. Nine @entity235 received a total of 24 discharges at varying energies (50 to 400 J). Nonsustained @entity1165 occurred with 13 shocks (62%) and transient @entity713 with 9 shocks (43%). There was no worsening in @entity340 as determined by right heart pressure measurements or right ventriculography. Programmed ventricular stimulation performed before the shocks and repeated before sacrifice failed to induce @entity943 . The endocardial lesion produced by the shock was roughly circular and its area correlated with both the magnitude of the shock as well as the atrial pacing threshold. Transmural @entity39 always occurred at the anulus when the A/V ratio was between 1.00 and 1.50 and preshock atrial pacing threshold suggested adequate wall contact (less than 1.5 mA). There was mild @entity32 of the adventitia of the right coronary artery near two discharge sites (both 200 J) and @entity32 of the media near one discharge site (400 J); no intimal involvement was seen.(ABSTRACT TRUNCATED AT 250 WORDS)
