Autonomic nervous system modulation before the onset of sustained atrioventricular nodal reentry tachycardia.
BACKGROUND
Our study was designed to analyze dynamic changes in autonomic tone before the onset of typical sustained atrioventricular nodal reentry tachycardia (AVNRT) in a large group of patients without structural heart disease.


METHODS
Twenty-four-hour Holter tapes from 42 consecutive patients (27 men and 15 women; aged 30 + or - 21 years) with several episodes of sustained typical AVNRT were analyzed. The diagnosis was validated by transesophageal electrophysiological study. The time-domain calculated parameters were SDNN, SDANN, rMSSD, pNN50; the frequency-domain parameters were low-frequency power (LF, 0.04-0.15 Hz), high-frequency power (HF, 0.15-0.40 Hz), very low-frequency power (VLF, 0.008 to 0.04 Hz) and LF/HF. The mean values in the hour before the onset of sustained AVNRT were compared with the mean values of 2 hours before and 1 hour after the onset of sustained AVNRT.


RESULTS
The mean SDNN, rMSSD, pNN50, HF were significantly decreased during the hour preceding the onset of AVNRT, when compared to the mean values observed during the time periods selected. Instead, the LF values and LF/HF were increased before the onset of sustained AVNRT. No significant change in the VLF and atrial ectopic beats were observed.


CONCLUSIONS
This study suggests that sustained typical AVNRT episodes are preceded by increase in adrenergic drive.
Chair of Cardiology, Second University of Naples, Monaldi Hospital, Naples, Italy.
Gerardo
G
Nigro
Vincenzo
V
Russo
Annabella
A
de Chiara
Anna
A
Rago
Nadia Della
ND
Cioppa
Raffaele
R
Chianese
Donatella
D
Manfredi
Raffaele
R
Calabrò
D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D002940:Circadian Rhythm; D015716:Electrocardiography, Ambulatory / Q000379:methods / Q000706:statistics & numerical data; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology*