The author's reply: The letter from Melbourne by Dumitrescu et al reporting complete heart block occurring in 3 of 36 patients after transcatheter closure of perimembranous ventricular septal defect adds weight to the concern expressed about this complication.1 Most disturbing is the detection of new‐onset heart block more than 3 years after the interventional catheter procedure. This supports the view that steroid treatment in the immediate postimplantation period will not necessarily prevent the late development of this important complication. The age or size of the affected patients at the time of device implantation is not stated, but all were children. Interventional catheterisation occlusion of a perimembranous ventricular septal defect in children, whether using the existing asymmetric Amplatzer occluder or other occlusive devices, should be performed with caution, and only as part of a prospective clinical trial or with submission of data to a registry. Continuing follow‐up of patients who have undergone the procedure is required. There is a responsibility to alert patients and their families to seek advice should relevant symptoms suggesting bradycardia occur, and also to report further experience of heart block should this be recognised. If similar experience of late‐onset heart block becomes widespread, the question of prophylactic pacemaker insertion may even need consideration.