1. Rhythm Problems Atrioventricular Septal Defect Alpay Çeliker MD. Hacettepe University Department of Pediatric Cardiology

2. Conduction System in AVSD Normal Heart Normal Heart AV node is located in the triangle of Koch AV node is located in the triangle of Koch AV Septal Defect AV Septal Defect AV node is located posteriorly

3. ECG in AVSD Prolonged PR interval Prolonged PR interval Left axis deviation and counterclockwise frontal plane loop Left axis deviation and counterclockwise frontal plane loop 1. Elongation of the anterior division of LBB 2.Anomalous development of anterior division of LBB 3. Interruption of the anterior division by anomalous insertion of chorda tendinea

4. ECG in AVSD II Incomplete RBBB pattern in 84 % Incomplete RBBB pattern in 84 % Evidence of atrial enlargement 54 % Evidence of atrial enlargement 54 % Q wave in V 6 84 % Q wave in V 6 84 % Additional factors that influences ECG Additional factors that influences ECG Size of ASD or VSD Size of ASD or VSD Amount of mitral and tricuspid regurgitation Amount of mitral and tricuspid regurgitation Pulmoner vascular resistance Pulmoner vascular resistance Associated defects Associated defects

5. Mechanisms of Arrhythmias Abnormalities inherent to malformation Abnormalities inherent to malformation Hemodynamic and hypoxic stress upon heart Hemodynamic and hypoxic stress upon heart Sequela of reparative surgery Sequela of reparative surgery Residual hemodynamic problems Residual hemodynamic problems

6. Rhythm Problems in AVSD Preoperative Rhythm Problems Preoperative Rhythm Problems Perioperative Rhythm Problems Perioperative Rhythm Problems Postoperative Rhythm Problems Postoperative Rhythm Problems

7. Preoperative Arrhythmias Acquired atrial tachyarrhythmias Acquired atrial tachyarrhythmias Late operation Late operation Atrial fibrillation may be seen 20 % and causes clinical deterioration Atrial fibrillation may be seen 20 % and causes clinical deterioration AV block AV block

8. Perioperative Arrhythmias Junctional Ectopic Tachycardia Junctional Ectopic Tachycardia AV Block AV Block

9. AVSD & Perioperative Arrhythmias With arrhythmia No arrhythmia AVSD Patients 2124 Mean age 0.9 ± 2.1 1.4 ± 1.9 Incomplete result 9/112/11 Pfammater et al. J Thorac Cardiovasc Surg 2002; 123: 258-262 AVSD with Arrhythmia N=21 AJR N= 8 SSS N=7 CAVB N=1 A Flutter N=1 JET N=1 Ectopic Beats N=1 Higher ACC, ECC time and TpI levels

10. Junctional Ectopic Tachycardia  ventricular rate  ventricular rate Loss of AV synchrony Loss of AV synchrony  Cardiac Output  Adrenergic Tone  Heart Rate

11. JET: ECG Diagnosis QRS configuration is similar to sinus or atrial paced beats QRS configuration is similar to sinus or atrial paced beats Rapid ventricular rate > or =to atrial rate Rapid ventricular rate > or =to atrial rate Dissociated atrial activity or retrograde 1:1 conduction or Wenckebach Dissociated atrial activity or retrograde 1:1 conduction or Wenckebach Failure to respond adenosine, overdrive pacing or cardioversion Failure to respond adenosine, overdrive pacing or cardioversion Warm-up phenomenon Warm-up phenomenon

12. Perioperative JET Increased duration of postoperative ventilation and CICU stay Increased duration of postoperative ventilation and CICU stay  incidence with ventricular muscle band resection, higher cardiopulmonary bypass temperature, transatrial RVOTO relief  incidence with ventricular muscle band resection, higher cardiopulmonary bypass temperature, transatrial RVOTO relief Postop JET N=37/343 10 % Fallot N= 25/114 21.9 % AVSD N=6/58 10.3% VSD N=6/161 3.7 % De-Leval group. J Thorac Cardiovasc Surg 2002; 123: 624-630. RVOT resection More important Than VSD closure

13. Treatment in Postop JET General Measures General Measures Optimize sedation/hemodynamics Optimize sedation/hemodynamics Correct fever Correct fever  Catecholamines  Catecholamines AV Synchrony AV Synchrony Class I and II AAD Class I and II AAD Hypothermia + Procainamide Hypothermia + Procainamide IV Amiodarone IV Amiodarone

14. Treatment Modalities in JET Walsh ED, et al. J Am Coll Cardiol, 1997; 29: 1046-1053

16. IV AMIODARONE N=11 SECONDARY THERAPY N=5 HYPOTHERMIA N=3 HYPO&PROC N=1 CAT REDUCTION N=1 INITIAL THERAPY N=6 SUCCESS 10/11 Laird et al. Pediatr Cardiol 2003; 24: 133-137.

17. Atrial pace slightly faster than JET from epicardial wires or Esophagus not an isolated therapy if JET rate >200 bpm * not an isolated therapy if JET rate >200 bpm AMIODARONEPROCAINAMIDE Core temperature 33-35 0 C using posterior cooling blanket under sedation, mechanic ventilation and paralysis

18. AV Blok Postoperative AV block has been reported to occur in 0-3.5 %. Postoperative AV block has been reported to occur in 0-3.5 %. 50 % of postoperative AV block resolves within the 8 days. 50 % of postoperative AV block resolves within the 8 days. Permanent pacemaker implantation after 15 days is prudent. Permanent pacemaker implantation after 15 days is prudent.

19. EPS Permanent Pacemaker InfraHisianBlock

20. Cardiac Pacing in AVSD SSS & Good AV Conduction: AAIR SSS & Good AV Conduction: AAIR SSS & AV Conduction Disturbance: DDD SSS & AV Conduction Disturbance: DDD AV Block: DDD AV Block: DDD Small Child ( <15 kg): Epicardial implant Small Child ( <15 kg): Epicardial implant SSS or AV Block with Atrial Tachycardia: Antitachycardia PM SSS or AV Block with Atrial Tachycardia: Antitachycardia PM Late Recovery of AV Conduction: 10 % Late Recovery of AV Conduction: 10 %

22. Perioperative and Longterm Arrhythmias Arrhythmia Type PerioperativeN-%Long-termN-%TotalN-% SVT 18 (5) 12 (4) 24 (7) At Fibrillation 7 (2) 21 (6) 25 (8) At Flutter 7 (2) 6 (2) 13 (4) AV Block 5 (2) 4 (1) 9 (3) Premature SVB & VB 23 3 (1) El-Najdawi et al. J Thorac Cardiovasc Surg 2000; 19: 980-90.

23. Atrial Arrhythmias Atrial Fibrillation Atrial Fibrillation Isthmus Dependent Atrial Flutter (IDAF) Isthmus Dependent Atrial Flutter (IDAF) Intraatrial Reentrant Tachycardia (IART) Intraatrial Reentrant Tachycardia (IART)

24. Risk of Atrial Reentry Tachycardia High Risk (> 10 %) High Risk (> 10 %) Fontan palliation Fontan palliation Mustard-Senning Mustard-Senning Total correction for Fallot or DORV Total correction for Fallot or DORV Sinus venosus or late repair of ASD II Sinus venosus or late repair of ASD II Moderate Risk (1-10 %) Moderate Risk (1-10 %) TAPVR TAPVR Ebstein’s anomaly Ebstein’s anomaly Complete AVSD Complete AVSD Mitral valve replacement Mitral valve replacement Low Risk (<1 %) Low Risk (<1 %) Early repair ASD II Early repair ASD II VSD repair VSD repair IART or IDAF

25. Therapy Of Atrial Arrhythmias DC Cardioversion DC Cardioversion AAD: Class Ic, III AAD: Class Ic, III AAD & PM AAD & PM Transcatheter RF Ablation Transcatheter RF Ablation Arrhythmia Surgery Arrhythmia Surgery Correction of residual defects Correction of residual defects Surgical ablation Surgical ablation Maze procedure Maze procedure

26. Transcatheter Ablation Atrial Fibrillation: His Ablation Atrial Fibrillation: His Ablation IDAF and IART: Creation of Block Line IDAF and IART: Creation of Block Line Use of saline irrigated catheters Use of saline irrigated catheters Use of 3D Anatomic Mapping Use of 3D Anatomic Mapping

27. EfficacyApplicationProblems Treatment Failures Adverse Effects Cost AAD RFA ATP ArrhythmiaSurgery Treatment Methods in Atrial Tachyarrhythmias

28. Sudden Death and AVSD Cardiac Defect Incidence 1000 pt/year Aortic Stenosis 5.4 D-TGA4,9 Fallot Tetralogy 1,5 Aortic Coarctation 1,3 AVSD0,9