Rhythm Problems Atrioventricular Septal Defect Alpay eliker MD

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

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

ECG in AVSD n n Prolonged PR interval 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

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

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

Rhythm Problems in AVSD n Preoperative Rhythm Problems n Perioperative Rhythm Problems n Postoperative Rhythm Problems

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

Perioperative Arrhythmias n Junctional Ectopic Tachycardia n AV Block

AVSD & Perioperative Arrhythmias With arrhythmia No arrhythmia AVSD Patients 21 24 Mean age 0. 9 ± 2. 1 1. 4 ± 1. 9 Incomplete result 9/11 2/11 Higher ACC, ECC time and Tp. I levels 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

Junctional Ectopic Tachycardia n n ventricular rate Loss of AV synchrony Cardiac Output Adrenergic Tone Heart Rate

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

Perioperative JET n n Postop JET N=37/343 10 % Increased duration of postoperative ventilation and CICU stay incidence with ventricular muscle RVOT resection band resection, higher More important cardiopulmonary bypass Than VSD closure temperature, transatrial RVOTO relief 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.

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

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

Walsh ED, et al. J Am Coll Cardiol, 1997; 29: 1046 -1053

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

JET Optimize hemodynamic variables, respiration, electrolytes, sedation, fever control Discontinue Catecholamines Atrial Pacing* Atrial pace slightly faster than JET from epicardial wires or Esophagus *not an isolated therapy if JET rate JT rate > 200 bpm or Persistent rate 170 -200 bpm AAD Hypothermia >200 bpm AMIODARONE PROCAINAMIDE Core temperature 33 -350 C using posterior cooling blanket under sedation, mechanic ventilation and paralysis

AV Blok n n n Postoperative AV block has been reported to occur in 0 -3. 5 %. 50 % of postoperative AV block resolves within the 8 days. Permanent pacemaker implantation after 15 days is prudent.

Postop CAVB Temporary Pacing Monitor 7 -10 days NSR or 1 o AVB Type 1, 2 o AVB EPS NSR, 1 o AVB, RBBB, LAD Type II, 2 o AVB Infra. Hisian Block Permanent Pacemaker 30 AVB

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

Perioperative and Longterm Arrhythmias Arrhythmia Type Perioperative N-% Long-term N-% Total N-% 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) 2 3 3 (1) SVT Premature SVB & VB El-Najdawi et al. J Thorac Cardiovasc Surg 2000; 19: 980 -90.

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

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

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

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