Special problems of pacing in children

Abstract

The number of children suffering from congenital or acquired rhythm disorders, and therefore being pacemaker dependent, is very small. This is one of the reasons why a special hardware has never been developed for this cohort. Pacemaker implantation into children does not differ substantially from operations in adults. But there are several important points which have to be fulfilled in these small patients in order to guarantee a complication free function. As most of these children remain pacemaker dependent a lifetime, it is of tremendous importance to minimize all revisions regarding the implanted systems and to enable our small patients a high and therefore nearly normal quality of life. Pros and cons of different surgical approaches, implantation sites and the problem of growth after pacemaker implantation in children are considered.

Figure 1

Transvenous pacing system in a 2990 gram and 47 cm long newborn via left superior vena cava to right ventricle (bipolar steroid eluting Medtronic screw in 4068-52cm) with the pulse generator (Medtronic MicroMinix 8360) in a subcutaneous left pectoral pouch (Although this operation was carried out by one of the authors (H.A.) in 1993, we are today no longer able to explain, why the generator was not implanted submuscularly in this case).

Figure 2

Posteroanterior radiography immediately before reintervention showing the inferior vena caval loop of the pacemaker lead strongly attached to the endothelium. The tip of the electrode is still attached the right ventricular wall. At that time an exit block was predominantly existent.

Figure 3

Transatrial lead implantation in a 12 year old boy with complex cardiac malformations. He had several open heart procedures and finally in 1995 a modified Fontan procedure with the addition of a fenestrated atrial baffle was accomplished. Sick sinus syndrome with bradycardia and dizziness was diagnosed in 2001. Because of the caval pulmonary connection a venous approach for lead insertion from cranial was impossible. Therefore, after median sternotomy a bipolar screw-in lead was implanted transatrially into the venous system (1) together with a right ventricular epicardial bipolar, steroid-eluting epicardial electrode (2). The pacemaker was programmed to DDDR mode, with the AV-conduction time so long that intermittent atrial pacemacer stimulation allowed physiologic stimulation of the ventricle. As an atrial back up lead a second epicardial bipolar steroid-eluting electrode was placed on the right atrium (3) with the lead body tunnelled to the generator pocket. In case of transatrial lead failure (e.g. exit block), revision would not neccessitate a rethoracotomy, but only an incision into the abdominal generator pocket and the exchange of the epicardial atrial lead.

Figure 4

Pulse generator placed in the abdominal wall (into the rectus sheath) in a 3 day old boy, 2700 grams, with congenital complete heart block. As this implantation was carried out in 1993, a unipolar epicardial lead was used (Osypka MP 47).