Lin et al evaluate patients who developed complete atrioventricular (AV) block following device closure of a perimembranous ventricular septal defect (VSD). They identified risk factors for this complication. The authors are from Fujian Medical University in China.

Patient selection: device occlusion of a perimembranous ventricular septal defect


Frequency: 0.7%


Most patients with complete AV block required insertion of a permanent pacemaker.



(1) diameter of the ventricular septal defect in mm

(2) diameter of the occluder device in mm


ratio of device to defect size =

= (diameter of device) / (diameter of defect)


A ratio >= 2.1 had a sensitivity of 0.86 and specificity of 0.66 for identifying risk of block.


Removal of the device in the month following placement was often successful in recovering normal conduction. However, about 57% of patients developed the block later.


Performance of ratio:

• The area under the ROC curve is 0.79.

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