[Effect of radiofrequency catheter ablation on autonomic tone in patients with common atrial flutter: difference depending on the site of ablation].
OBJECTIVE
Radiofrequency catheter ablation (RFCA) of the inferior vena cava-tricuspid annulus isthmus has become an effective procedure for radical treatment of common atrial flutter. This site is close to the right atrial posteroseptal region, so vagal denervation after slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia can also occur after the procedure. To confirm this hypothesis, we tested whether autonomic disturbance can occur after RFCA in 16 patients with common atrial flutter.


METHODS
Parameters of the autonomic function were measured using several components of the time domain analyses and power spectra of heart rate variability calculated from Holter recordings and the baroreflex sensitivity. Patients were divided into 2 groups based on the location of the ablated area: the isthmus group (9 patients) with the ablated area of the exact isthmus, and the posteroseptal group (7 patients) with the ablated area slightly shifted toward the right atrial posteroseptal position. All values after RFCA were compared with those before RFCA, and the ratio (after/before) was compared between the groups. The correlation between the ratio and cumulative delivered energy was also studied for each parameter.


RESULTS
After RFCA, the heart rate increased, and the SD, rMSSD and pNN50 decreased significantly in the posteroseptal group, whereas no significant changes occurred in the isthmus group. The high frequency of the power spectra decreased after RFCA only in the posteroseptal group, and the ratio was significantly smaller in the posteroseptal group compared to the isthmus group. A significant reverse correlation between the ratio of the high frequency and cumulative energy was observed only in the posteroseptal group. The baroreflex sensitivity tended to be diminished after RFCA only in the posteroseptal group.


CONCLUSIONS
Vagal denervation can occur after RFCA of common atrial flutter when the ablation site is shifted toward the right atrial posteroseptal region.
Kawamura
Y
Y
First Department of Internal Medicine, Asahikawa Medical College, Hokkaido.
Yokoyama
A
A
Kakuchi
H
H
Sato
N
N
Kikuchi
K
K
D001282:Atrial Flutter / Q000503:physiopathology / Q000601:surgery*; D001341:Autonomic Nervous System / Q000502:physiology*; D017115:Catheter Ablation; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D014261:Tricuspid Valve / Q000601:surgery; D014628:Vagotomy; D014682:Vena Cava, Inferior / Q000601:surgery