[Compromise of the cardiac autonomic nervous system in patients with Fontan-type circulation: preliminary data].
BACKGROUND
Rhythm disturbances are frequent after Fontan operations. Arrhythmias related to reduced heart rate variability (HRV) have been described in various cardiovascular diseases.


METHODS
We attempted to investigate HRV in 12 patients who underwent Fontan operation (age 11.4 +/- 3 years). Results were compared to a control group of 13 children matched for age, sex and heart rate (10.4 +/- 3 years). All patients underwent 24-hour Holter monitoring. The following time domain indexes were calculated: mean duration of RR intervals, standard deviation of all RR intervals (SD), square root of the mean squared differences of successive RR intervals (r-MSSD), percentage of differences between adjacent RR intervals > 50 msec (pNN50). The following frequency domain indexes were calculated: total power (TP), low frequency (LF), high frequency (HF), LF/HF ratio.


RESULTS
The following indexes were significantly reduced in Fontan patients: SD (p < 0.0001), r-MSSD (p < 0.0001), pNN50 (p = 0.0002), TP (p < 0.0001), LF (p < 0.0001), HF (p = 0.0001). LF/HF increased significantly (p = 0.04). No differences were detected according to the type of operation (cavopulmonary connection vs atriopulmonary connection) or clinical status.


CONCLUSIONS
Patients with Fontan circulation had a significantly reduced HRV and particularly abnormal sympatho-vagal balance. Surgery on the caval veins and the atria alters the intracardiac ganglia that are abundant at the cavo-atrial junction and in the myocardium of the right atrium. Abnormalities of HRV in Fontan patients may act as a co-factor in the initiation of arrhythmia in these patients.
Butera
G
G
Service de Cardiologie Pédiatrique, Hôpital Necker Enfants Malades, Paris, France.
Bonnet
D
D
Bonhoeffer
P
P
Aggoun
Y
Y
Iserin
L
L
Sidi
D
D
Kachaner
J
J
Villain
E
E
D000293:Adolescent; D001341:Autonomic Nervous System / Q000503:physiopathology*; D016009:Chi-Square Distribution; D002648:Child; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000706:statistics & numerical data; D006321:Heart / Q000294:innervation* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D018709:Statistics, Nonparametric; D018785:Tricuspid Atresia / Q000503:physiopathology / Q000601:surgery