Late recovery of atrioventricular conduction after postsurgical chronic atrioventricular block is not exceptional.
OBJECTIVE
Postsurgical atrioventricular block may complicate surgery for congenital heart defects and is generally considered permanent when persisting longer than 14 days after surgery. In this study, we evaluate the occurrence of spontaneous late recovery of atrioventricular conduction in postsurgical chronic atrioventricular block and discuss its clinical implications.


METHODS
We retrospectively reviewed all cardiac surgical procedures on cardiopulmonary bypass between January 1993 and November 2010 in subjects younger than 18 years. Patients with postsurgical advanced second- or third-degree atrioventricular block persisting longer than 14 days after surgery were included.


RESULTS
Of a total of 2850 cardiac surgical procedures on cardiopulmonary bypass, 59 (2.1%) were immediately complicated by chronic postsurgical atrioventricular block of advanced second (n = 4) or third degree (n = 55). In another 6 patients (0.2%), late occurrence of chronic advanced second- (n = 3) or third-degree (n = 3) atrioventricular block, without signs of any etiology other than previous surgery, was seen 0.4 to 10 years after surgery (median, 5.7 years). Late (>2 weeks) regression to either completely normal atrioventricular conduction or asymptomatic first-degree atrioventricular block occurred 3 weeks to 7 years (median, 3.1 years) after surgery in 7 (12%) patients with immediate postsurgical chronic atrioventricular block.


CONCLUSIONS
Complete recovery of atrioventricular conduction or regression to asymptomatic first-degree atrioventricular block occurred in 12% of patients with postsurgical chronic second- or third-degree atrioventricular block. To prevent unnecessary adverse side effects of chronic ventricular pacing and to prolong battery longevity, ventricular pacing should be minimized in patients with recovered normal atrioventricular conduction.
Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands; Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands. Electronic address: i.vangeldorp@maastrichtuniversity.nl.
Irene E
IE
van Geldorp
Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands; Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Pediatric Cardiology, University Hospitals Leuven, Leuven, Belgium.
Ward Y
WY
Vanagt
Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
Guusje
G
Vugts
Department of Cardiology, University Hospitals Leuven, Leuven, Belgium.
Rik
R
Willems
Department of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium.
Filip
F
Rega
Department of Pediatric Cardiology, University Hospitals Leuven, Leuven, Belgium.
Marc
M
Gewillig
Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands; Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands.
Tammo
T
Delhaas
D000293:Adolescent; D054537:Atrioventricular Block / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D007223:Infant; D020127:Recovery of Function; D012189:Retrospective Studies; D013997:Time Factors