A single institution experience with pacemaker implantation in a pediatric population over 25 years.

BACKGROUND: With the development of new technical devices and software more appropriate for pediatric patients, pacemaker implantations in children and young adults have increased over time. It is necessary to monitor the mid- and long-term consequences. The decision for the implantation of a cardiovertor defibrillator (ICD) in children remains challenging despite technical improvements. OBJECTIVE: To assess the safety of pacemaker implantation in children, to review old and new indications, and to point out changes of management over time. PATIENTS AND METHODS: Between 1984 and 2009, 181 patients required the implantation of a pacemaker or an ICD device at the Heart and Diabetes Centre in Bad Oeynhausen, Germany. Their charts have been reviewed pro- and retrospectively for indications, complications, longevity of the device, and the natural course. RESULTS: Indications have been high-degree atrioventricular block in 65% (postoperative 55%) and sinus node dysfunction in 24% (postoperative 90%), including three patients with vasovagally mediated significant bradycardia. Eleven percent required the implantation of an ICD device secondary to significant ventricular arrhythmias. The indication was class II in one-third of all patients. Complications requiring revision occurred in six patients (3.3%); one of them required removal of the device due to an infection. Ten patients died, but none related to pacemaker implantation. CONCLUSION: Pacemaker implantation even in young pediatric patients is generally safe. No complication led to the death of a patient. The number of class II indications has been increasing. The future aim is to improve pediatric algorithms and to prevent unnecessary pacing.

Endocardial pacing after Fontan-type procedures.

BACKGROUND: Sinus node dysfunction is a frequent complication of Fontan-type procedure. Epicardial pacing is considered as the standard treatment for these patients. METHODS AND RESULTS: We evaluated an endocardial approach in seven patients using a 4.1 French bipolar lumenless lead (SelectSecure) that is positioned through a steerable guiding catheter. Either a purely transvenous or an open transatrial approach can be used for lead placement. The smallest child weighed 12 kg. Individual anatomy was assessed preimplantation using magnetic resonance imaging and injection of radiographic contrast agent through the guiding catheter. A pullback pressure recording was used to confirm unimpaired blood flow into the pulmonary artery. Five of our seven patients underwent de novo transvenous atrial lead implantation for AAIR pacing. In the remaining two patients, both atrial and ventricular leads were inserted. One patient with an intraatrial tunnel underwent transvenous-lead placement. The remaining patient with an extracardiac conduit received atrial and ventricular leads implanted through a guiding catheter inserted through an atriotomy. The postoperative management included short- or long-term oral anticoagulation. CONCLUSIONS: Transvenous endocardial lead implantation avoids the problem of increasing capture thresholds typically observed with epicardial leads. Due to its high tensile strength and lumenless design, the isodiametric lead is expected to remain extractable for an extended period of time.

Low vs standard calcium dialysate in peritoneal dialysis: differences in treatment, biochemistry and bone histomorphometry. A randomized multicentre study.

BACKGROUND: In patients undergoing peritoneal dialysis (PD), low-calcium dialysate (LCD) has been proposed as the first choice for a better control of renal osteodystrophy. Our aim was to compare the effects on bone metabolism of LCD (calcium: 1.25 mmol/l) with that of a standard calcium dialysate (SCD; calcium: 1.75 mmol/l). METHODS: Forty-four PD patients were randomized to receive LCD or continue on SCD for a period of 12 months. Bone biopsies were taken at baseline and at 12 months. Biochemical data and treatment were evaluated every 3 months. RESULTS: Twenty-four patients completed the study. In the SCD group (n = 10), nine out of the 10 patients were initially diagnosed with adynamic bone lesion (ABL). After 1 year, six continued having ABL and three patients moved to high-turnover bone lesion (HTBL). The other patient, initially diagnosed with HTBL, changed to ABL. In the LCD group (n = 14), 10 patients were initially diagnosed with ABL. At 1 year, six of them continued having ABL and four patients changed to HTBL. Four patients were initially diagnosed with HTBL and did not change. Comparison between LCD and SCD groups showed an increase in serum parathyroid hormone (PTH) levels starting at month 3 and a higher intake of calcium salts in the former group (P<0.01). Serum calcium, phosphate levels and bone histological outcome did not differ between the two groups. CONCLUSIONS: LCD use for 1 year was associated with an increase in PTH levels, but did not lead to histological changes different from those observed in SCD group. The LCD solution allowed a higher oral intake of calcium salts with a satisfactory control of the serum Calcium-Phosphorus product.