Does chronic pacing affect exercise capacity after Mustard operation for transposition of the great arteries?

Sudden cardiac death and malignant arrhythmias: the scope of the problem in adult congenital heart patients

A key component of recognizing sudden cardiac death (SCD) risk in the adult congenital heart disease (ACHD) patient is the recognition of heart failure risk for each physiology. The risk of SCD is an accrued phenomenon, representing the influences of anatomy, genetics, surgical and catheter interventions, and long-term sequelae of residual hemodynamic issues. These all lead to a substrate for tachyarrhythmia. It is beneficial in thinking about all of the potential combinations of CHD anatomy and physiologies to categorize SCD risk for the ACHD patient in terms of systemic left-ventricular failure, systemic right-ventricular failure, subpulmonary ventricular failure, the dyssynchronous contractility states due to bundle branch block, and single-site ventricular pacing. This article reviews important issues in arrhythmogenesis for ACHD patients with all of these physiologies and discusses potential cardiac rhythm device-management needs.

Twenty years of paediatric cardiac pacing: 515 pacemakers and 480 leads implanted in 292 patients

AIMS

The aim of this study was to evaluate long-term outcome of pacemakers (PMs) in paediatric patients.

METHODS AND RESULTS

Patients' data were retrospectively reviewed. We recorded the techniques and systems used, any complication, and outcome. Endocardial leads were inserted by transcutaneous puncture of subclavian vein and fixed with a non-absorbable ligature, and epicardial leads by standard surgical technique. Lead survival was calculated and plotted with the product limit method of Kaplan-Meier. Between 1982 and 2002, 292 patients, aged 8+/-7 years (range 1 day-18 years), underwent PM implantation: the first PM had endocardial leads in 165 patients and epicardial in 127 patients. Structural heart disease (HD) was present in 239 patients. Follow-up was 5+/-4 (range 0.1-18) years. There were no pacing-related deaths. In total, 211 endocardial implantation procedures with 90 atrial and 165 ventricular leads and 145 epicardial procedures with 103 atrial and 123 ventricular leads were performed. Early (<3 months) complications: haemothorax occurred in 3.5% of endocardial leads and dislodgement was not significantly different for atrial and ventricular endocardial leads. Late complications: 63 leads failed (48 epicardial), with the worst outcome for conventional epicardial leads (31 vs. 9% endocardial, P<0.05; steroid eluting 8% epicardial vs. 5% endocardial, P=NS). Endocardial atrial leads failed (7%) in operated HD and ventricular leads failed (6%) after body growth, without difference in estimated mean survival time (11 years). Early and late PM infection/erosion was approximately 2% in all patients.

CONCLUSION

Pacing in children shows good results, but complications are frequent and related to leads. Endocardial pacing showed better long-term outcome.

Upgrade of Single Chamber Pacemakers with Transvenous Leads to Dual Chamber Pacemakers in Pediatric and Young Adult Patients

Children with single chamber pacemakers, in adolescence and young adulthood, may be upgraded to dual chamber systems, but there are no published data about indications, timing, and complications. Upgrading was attempted in 18 patients with transvenous pacing leads. A retrospective analysis of all collected data was performed. At initial pacemaker implantation (mean +/- SD, 9.3 +/- 4.1 years), the pacing mode was VVIR (n = 13 patients) and AAI/AAIR (n = 5 patients). After 72 +/- 41 months of follow-up, at the age of 15.5 +/- 5.2 years, upgrade was undertaken because of the patient's age at elective generator replacement (n = 3 patients), ventricular dysfunction (n = 7), syncope/presyncope (n = 3) in patients with VVIR pacing, atrioventricular block (n = 2), and/or drug refractory supraventricular tachyarrhythmias (n = 4) in patients with atrial pacing. In comparison with single chamber pacemaker implantations, the average procedural time and the average fluoroscopy time were not significantly longer. All suitable preexisting leads were incorporated in the new pacing system. Leads were inserted via the ipsilateral subclavian vein in 16 patients. Venous occlusion was found in two patients: in the first the procedure was not performed; in the second, the contralateral vein was used and the old lead was abandoned. There were no procedural complications. During a follow-up of 14 +/- 11 months, ventricular dysfunction worsened in five of seven patients; other patients benefitted symptomatically. In conclusion, pacemaker upgrade is technically challenging but feasible and safe and may be beneficial for some patients.