Heart rate variability in patients undergoing univentricular heart repair.
OBJECTIVE
Altered cardiac autonomic control may play a role in the long-term outcome of patients undergoing univentricular heart repair. This study was undertaken to compare bidirectional superior cavopulmonary anastomosis with preserved antegrade pulmonary blood flow and total cavopulmonary connection, with regard to their effects on cardiac autonomic activity, as measured by heart rate variability indices, prior to and early after surgery.


METHODS
This prospective study included 46 patients (27 with bidirectional superior cavopulmonary anastomosis and 19 with total cavopulmonary connection. Heart rate variability was measured preoperatively and at 2 and 9 months postoperatively. The heart rate variability was measured by a 900-s electrocardiogram recording. Comparisons were drawn between and within groups, using standard statistical methods.


RESULTS
All heart rate variability parameters were comparable in the 2 groups preoperatively. At the first follow-up, all heart rate variability parameters had decreased in both groups, but the decreases were not statistically significant. Between-group comparisons showed significantly higher parasympathetic and lower sympathetic tone in the bidirectional superior cavopulmonary anastomosis group. At the second follow-up, the bidirectional superior cavopulmonary anastomosis group had a significant increase in overall cardiac autonomic tone, and the total cavopulmonary connection group had a significant increase in parasympathetic tone, compared to the first follow-up. Between-group comparisons showed higher cardiac autonomic tone in the bidirectional superior cavopulmonary anastomosis group.


CONCLUSIONS
Total cavopulmonary connection leads to a significant reduction in overall cardiac autonomic tone, compared to bidirectional superior cavopulmonary anastomosis with antegrade pulmonary blood flow.
Department of Physiology, All India Institute of Medical Sciences, New Delhi, India.
Kushal
K
Madan
Pankaj
P
Garg
Kishore Kumar
KK
Deepak
Sachin
S
Talwar
Balram
B
Airan
Shiv Kumar
SK
Choudhary
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006339:Heart Rate; D006352:Heart Ventricles / Q000002:abnormalities / Q000294:innervation / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011446:Prospective Studies; D011652:Pulmonary Circulation; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
Autonomic nervous system; congenital; electrocardiography; fontan procedure; heart defects; sympathetic nervous system