Controlled Ventilation Enhances Catheter Stahility During Radiofrequency Ahlation FRANAHVAZIR-MARINO, MING-LON YOUNG, VIKAS KOHLI, MIGHAEL BARRON,* and GRACE S. WOLFF From thefDepartment of Pediatricsiand *Anesthesiology/University of Miami./Miami, FL ^y " '-4 VAZIR-MARINO, F., ET AL.: Controlled Ventilation Enhances Catheter Stability During Radiofrequency Ahlation/Variations in the amplitude of the atrial and ventricular depolarization waves of the intracar- diac electrogram occur during different phases of respiration. Therefore, we tested whether controlled ventilation would reduce ablation attempts and increase the rate of success in patients undergoing ra- diofrequency ablation with general anesthesia. Thirty-eight children were divided into two groups: (1) controlled and (2) noncontrolled or cyclic ventilation. In the controlled ventilation group, the mapping electrogram was recorded during sustained inspiration, sustained expiration, and cyclic ventilation. Ab- lation was done in the phase of ventilation that had the least variability in atrial and ventricular ampli- tudes. Seventeen patients in the controlled ventilation group had tracings adequate for review. In eight pa- tients, ablation was done during sustained inspiration with the percentage change of atrial and ventricular amplitudes (15% ± 16% and 13% ± 16%, respectively) being < that during sustained expiration (38% ± 27%, P = 0.04 and 20% ± 21 %) or during cyclic ventilation (57% t 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 inspi- ration (21% ± 14%, P = 0.01 and 11% ± 6%, P = 0.01) or during cyclic ventilation (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 ivere less in the controlled ventilation group 1 (3 ± 2), as compared to the cyclic ven- tilation group 2 (8 ± 8; P < 0.02). We concluded that controlled ventilation reduced the number of abla- tion attempts and facilitated the ablation procedure. (PACE 1999; 22[Pt. I]:86-90) electrophysiologic study, Wolff-Parkinson-White syndrome, atrioventricular nodal reentrant tachycardia Introduction Although radiofrequency (RF) catheter abla- tion in children with cardiac arrhythmias has a high success rate,^^ many factors can influence the outcome. These factors include; the location of the target site, the stability of the ablation catheter, and the catheter tissue contact.•* General anesthesia has been used in children for this procedure to ensure that patients are adequately sedated.'' When the mapping catheter is at the target location, near the atrioventricular (AV) groove, marked variations in This work is supported partially by the Children's Cardiac: Re- search Foundation of Florida, Miami, Florida, Address for reprints: Ming-Lon Young, M.D., Department of Pedialrics. (R-7fi), University of Miami, P.O. Box 016960, Mi- ami, FL 3310i: Fax; 305-324-6012; e-mail: SueMingCrr'aol.com — -A.'" ' Received September 23. 1997; revised February 18, 1997; ac- cepted February 25, 1997. the amplitude of the atrial (A) and ventricular (V) depolarization waves occur in the intracardiac electrogram during the phases of respiration. This may reflect catheter instability and adversely affect results. When the patient is maintained in one phase of the ventilatory cycle, there is a significant reduction in the variahility of the A and V wave amplitudes. This method of controlled ventilation during RF catheter ablation may contribute to the final success of the ablation procedure. Methods Over a IV2 year period, 38 children and young adults, who had RF ablation for cardiac arrhyth- mias under general anesthesia, were included in this study. They were divided into two groups; (1) 19 patients in the controlled ventilation group (de- fined as mechanically sustained inspiration or ex- 86 January 1999, Parti PACE, Vol. 22