Controlled ventilation enhances catheter stability during radiofrequency ablation

Variations in the amplitude of the atrial and ventricular depolarization wa ves of the intracardiac electrogram occur during different phases of respir ation. Therefore, we tested whether controlled ventilation would reduce abl ation attempts and increase the rate of success in patients undergoing radi ofrequency ablation with general anesthesia. Thirty-eight children were div ided into two groups: II) controlled and (2) noncontrolled or cyclic ventil ation. In the controlled ventilation group, the mapping electrogram was rec orded during sustained inspiration, sustained expiration, and cyclic ventil ation. Ablation was done in the phase of ventilation that had the least var iability in atrial and ventricular amplitudes. Seventeen patients in the co ntrolled ventilation group had tracings adequate for review. in eight patie nts, ablation was done during sustained inspiration with the percentage cha nge of atrial and ventricular amplitudes (15% +/- 16% and 13% +/- 16%, resp ectively) being ( that during sustained expiration (38% +/- 27%, P = 0.04 a nd 20% +/- 21%) or during cyclic ventilation (57% +/- 27%, P < 0.01 and 54% +/- 26%, P = 0.003). In nine patients, ablation was done during sustained expiration with the percentage change of atrial and ventricular amplitudes (5% +/- 5% and 5% +/- 2%) being less than that during sustained inspiration (21% +/- 14%, P = 0.01 and 11% +/- 6%, P = 0.01) or during cyclic ventilat ion (68% +/- 23%, P < 0.001 and 48 +/- 26%, P = 0.001). We achieved success with each patient in both groups, but the number of ablation attempts were less in the controlled ventilation group 1 (3 +/- 2), as compared to the c yclic ventilation group 2 (8 +/- 8; P < 0.02). We concluded that controlled ventilation reduced the number of ablation attempts and facilitated the ab lation procedure.