Prolonged PR Interval (First-degree AV Block)

(Click on the image to enlarge)

 

VSD enlargement (Surgery)

To enlarge the VSD without causing AV block...

D-loop ventricles - Raise the roof (Enlarge VSD in anterior-superior direction)

L-loop ventricles - Lower the floor (Enlarge VSD in posterior-inferior direction)

Without injuring the aortic valve in the process!

ICU: Postoperative AV block - Recovery

Study period: 1991-4. Boston Children's Hospital. n=2698 surgeries (73% on bypass).

Overall incidence of AV block was 3% (n=54).

Common diagnoses associated with development of AV block were VSD, Tetralogy, LVOTO repair, L-TGA and others. 

32 recovered conduction in 30 days after surgery (Graph below shows the postop. day at which conduction recovered in these 32 patients). 

9 did not recover conduction in 30 days after surgery. 

Weindling SN., et al. Duration of complete atrioventricular block after congenital heart surgery. Am J Cardiol 1998;82:525-527.

Quiz: EKG, Postop. Repair of AVSD

5 mo old, Postop. day 3 after AVSD repair.
(Click on the image to enlarge)

1) What is different between first half and second half of the EKG trace?

2) What type of pacing is being done?

3) What is the pacing rate?

4) What is the atrial rate?

5) What is the native ventricular rate?

6) What is the diagnosis for the underlying rhythm?

Conduction System - Normal Heart vs. AVSD (One aspect of it)

Images from Kirklin/Barratt-Boyes Cardiac Surgery 3rd edition (2003)

AVSD (p 813)
Normal Heart (p 15)


Conduction system in VSDs:
Figure below shows the AV node and His bundle relationship to membranous VSD and inlet-muscular VSD. Note: Inlet-muscular VSD is different from inlet-VSD in AVSD. The latter is shown in the first figure above.
(From Anderson RH, Wilcox BR. J Cardiac Surg. 1992;7:17-34)