Study of the cardiac conduction tissues in the paediatric age group.

We have reviewed our experience with study of the conduction system of the heart and tried to condense our experience in the hope of aiding others to study this neglected part of the heart. The techniques involved are not complicated but do require patience and attention to detail. The key to success is the ability to cut serial sections, and to mount and study sub-serial sections. The techniques used are briefly described and then attention is given to the removal of blocks, the single most important step in the whole procedure. Advice is offered on the optimal method of studying the sinus node and the atrioventricular junctional area in the normal heart. Thereafter methods are described for studying the conduction systems in hearts with abnormal atrioventricular nodes, with ventricular septal defects and with ventricular pre-excitation. Similar attention is then paid to sudden infant death syndrome with regard to the conduction system, to congenitally complete heart block and finally to acquired disease in congenitally malformed hearts. Hope is expressed that more may become interested in the study of this fascinating system, or else refer suitable hearts to those who already are.