Reinnervation after heart transplantation in children: results of short-time heart rate variability testing.
OBJECTIVE
To detect impairment in short-term heart rate variability (HRV) in children after heart and heart-lung transplantation (TX) as reported in adults. To assess vagal and sympathetic influence on the donor heart rate using frequency domain analysis of HRV.


RESULTS
Measurement of short-term HRV was performed in 17 patients (age 16.9+/-3.6, 6.1+/-3.7 yr after TX) and 12 healthy controls (age 14.8+/-3.0 yr). Testing consisted of a resting phase of 15 minutes followed by a tilt phase of 45 min. All HRV parameters were significantly impaired in transplanted patients: RR interval (RRI) 717.2+/-122.5 m/s (controls 827+/-139.7, p<0.05), standard deviation of RR interval (RRI-SD) 20.1+/-15.5 (89.9+/-38.4, p<0.001), RRI at tilt 607.9+/-79.7 (654.0+/-104.7, NS), RRI-SD at tilt 21.1+/-20.0 (60.4+/-31.4, p<0.001). Low-frequency (LF)/High-frequency (HF) ratio of HRV showed prominent sympathetic influence in TX-patients (3.38+/-5.60 vs. 1.18+/-0.86, NS) increasing during tilting (5.91+/-8.36 vs. 4.74+/-5.27, NS). In subgroup analysis, 4 yr after TX an increasing sympathetic control of heart rate was observed.


CONCLUSIONS
Short-term HRV is severely impaired in children after TX. If changes are observed, they are time-related and show increasing sympathetic influence starting from 4 yr after TX.
Pozza
Robert Dalla
RD
Department of Pediatric Cardiology, Ludwig Maximilians University, Munich, Germany. Robert.DallaPozza@med.uni-muenchen.de
Kleinmann
Arne
A
Bechtold
Susanne
S
Fuchs
Alexandra
A
Netz
Heinrich
H
D000293:Adolescent; D000328:Adult; D001341:Autonomic Nervous System / Q000000981:diagnostic imaging / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D016027:Heart Transplantation / Q000379:methods*; D006801:Humans; D008297:Male; D018667:Tilt-Table Test; D013997:Time Factors; D014463:Ultrasonography; D014630:Vagus Nerve / Q000000981:diagnostic imaging / Q000502:physiology