1. PACEMAKER IMPLANTATION Alpay Celiker M.D. Acıbadem University

2. Pacing in Pediatric & Congenital Heart Disease • Advances in lead and device technology allow pacemaker system implantation in children and even in neonates • Specific problems in children such as small vessel size, cardiovascular abnormalities often lead to implant problems. • Physical activity and somatic growth may affect lead longevity in young patients

3. Points of Interest • Leads • Endocardial, or epicardial • Passive or active fixation • Chamber Paced • VVIR, DDD, or VDD

4. Leads generally more reliable than epicardial implants • Procedure more easy • Less thresholds • Fast adaptation to new pacemaker systems Pros and Cons of Transvenous Leads Venous obstructions Pace related impaired ventricular function. Lead infections Lead extraction necessity Interaction with cardiac valves Impossible in some patients

6. Venous Occlusion: 11 out of 85 (13%) total venous obstruction; 10 (12%) partial obstruction. Age, body size and lead type not associated with occlusion > 3 years . Bar Cohen 2006 Tricuspid valve issue: 27 out of 123 TR increased. No severeTR. No change (63%) or improved (12%). Berul 2008.

7. An inhomogeneous and dyssynchronous electrical activation of ventricles, leading to changes in myocardial architecture and left ventricular mechanical contractions. This problem is secondary to right ventricle apical pacing via transvenous pacing. Karpawich P. Pace 2008

8. Pediatric Pacemaker Infections* • Perioperative Infections (before discharge): • Superficial 1,2 % • Deep 0,2 % • Early Pacemaker Infections (< 60 days) • Superficial 3,1 % • Deep 1,2 % • Late Pacemaker Infections • Superficial 0,5 % • Deep 0,7 % • Staphylococcus species were isolated in 44 % • Increased Risks • Reintervention • Down syndrome • Subcutaneous  preperitoneal pocket *Cohen et al J Thorac Cardiovasc Surg 2002; 124.

10. Lead Extraction in Children.Why? • Remove the intravascular and intracardiac lead material • Relieve and reconstruct the venous access for the new leads • Prevent lead related infection

11. Indications • Class I: • a: sepsis • b: life-threatening arrhythmia • c: life threatening condition • d: thromboembolic event caused by retained lead • Obliteration of all useable veins • Lead interfereres with the operation of another device

12. Pros: • Venous access not required • Usable patients with compromised venous access • Allows left ventricular pacing, even in small patients • Dual chamber pacing in small patients Epicardial Pacing Cons Implantation procedure more invasive than endocardial Surgery required Leads are weaker

13. Epicardial versus Endocardial Pacing: Conclusion Epicardial: <15 kg Compromised venous access or a univentricular heart Pace the left ventricle Endocardial Possible implant <15kg Venous occlusion Risks of future lead extraction Beware of pacing induced heart failure

14. Epicardial Pacing A substantial proportion of patients with epicardial pacemakers do, however, require reintervention within five years. Median sternotomy is a risk factor Noiseux et al. Thirty years of experience with epicardial pacing in children. Cardiol Young 2004

15. Preserved cardiac synchrony and function with single-site left ventricular epicardial pacing during mid-term follow-up in paediatric patients. Tomaske M, Breithardt OA, and Bauersfeld U. Europace 2009.

17. DDD vs VDD • VDD pacing may be an alternative for DDD pacing in children with normal sinus node function. • Ovsyshcher, Rosenthal and Seiden et al. have been showed good results with this mode of pacing. • Late results of this mode of pacing seems to encourage • Atrial electrogram amplitude was decreased in children without any atrial sensing problem. Loss of atrial sensing can be a problem in children with operated congenital heart diseases. • It may be first choice older children with congenital AV block and normal sinus node dysfunction.

18. VVIR versus DDD Pacing DDD Pros and Cons • Pros: Physiological heart rate response, AV synchrony maintained, reduced risk of atrial fibrillation • Cons: Two leads required, larger generator, faster heart rates than VVIR, pacemaker mediated tachycardia VVIR Pros and Cons • Pros: One lead required, Smaller generator, gives satisfactory exercise tolerance, slower heart rates than DDD • Cons: Heart rate response is not physiological, loss of AVsynchrony,

19. VDD Pacing • Disadvantages • Atrial sensing problems in postop. cases • Relative change of atrial dipole with the growth • Decrease of AV synchrony with time • Lack of active fixation • Large electrodes • No indication in SSS • Lack of epicardial use • Advantages • Single lead dual chamber sensing • Avoid of many electrodes • Provide AV Synchrony • Avoid of venous thrombosis??

20. Site Selective Pacing Select Secure system: steroid eluting, bipolar, lumenless, non-retractable screw-in 4,1 F lead (model 3830, Medtronic, Inc.), delivered through a 8F steerable catheter (Select Site) • Pioneereed by Karpawich. • Implant possible to desired place • Less material at venous system and heart • Similar results compared to conventional systems • Lead extraction issue? • Long-term results? Karpawich et al. Altered cardiac histology following apical right ventricular pacing in patients with congenital atrioventricular block. Pacing ClinElectrophysiol 1999

21. Conclusion • Long term complications of pacing in childhood include venous occlusion, impaired ventricular function, lead failure, and risks of multiple implants and explants. • Right ventricular apical pacing should be minimised where possible. • In small infants epicardial pacing should be encouraged. • Long term complications largely relate to problems with the leads.