Arrhythmias in Post-operative VSD Jing-Ming Wu, M.D. Professor & Chairman of Pediatrics, National Cheng Kung University Hospital Tainan, Taiwan
Arrhythmias in Post-operative VSD Not uncommon (30%), and it could increase the morbidity & mortality Symptomatic: Complete AV block Pfammatter et al. J Thorac Cardiovasc Surg 2002;123:258-62 Tachycardia (JET, atrial tachycardias etc) Asymptomatic: RBBB : 30-80 % RBBB + LAFB: 4-12 % Atrial or ventricular ectopies
Cartoon shows the relation of conduction system and VSD From RH Anderson et al Pediatric Cardiology 3rd Edition
Is Complete Heart Block After Surgical Closure of Ventricular Septal Defect Still an Issue?
Incidence of CAVB in VSD repair Andersen et al. Ann Thorac Surg 2006;82:948-57
Incidence of CAVB in VSD repair North America PCCC database Tucker et al. JACC 2007:50:1196-200
CAVB in Postoperative VSD Incidence: 0-8% Andersen et al. Ann Thorac Surg 2006;82:948-57 1-2% transient CAVB (97% regained normal AV conduction within 9 D) < 1 % need permanent pacemaker 0.1% late-onset complete AV block Risk factors: Down syndrome 10% late recovery of surgical CAVB Tucker et al. JACC 2007:50:1196-200 Van Geldorf et al. J Thorac Cardiovasc Surg 2012
5 M/O, large VSD II, PAH s/p (CAVB with A rate 190 bpm; V rate 110 bpm) P P P P P P 12 hour later: normal sinus rhythm
7 M/O, Down with large VSD II, ASD s/p CAVB with P rate 170 bpm, QRS rate 100 bpm P P P P P P P P P P P
2 nd day after operation: still CAVB P P P P P P P P 3 rd day after operation: high degree AV block P P P P P P P P P
4 th day after operation: 1st degree AVB & RBBB Rhythm II 5 th day after operation: sinus rhythm with RBBB Rhythm III
Post-OP. 18th day AR:160 bpm VR: 50 bpm
Late Onset of Post-Op. CAVB 4/4432 (0.1%) VSD repair (PCCC database) Tucker et al. JACC 2007:50:1196-200 Moss et al. 20 p ts with late onset CAVB from 1 month to 14 years (10 TOF, 5 ECD, 4 VSD, 1 TGA) The American J of Cardiology. 1972; 30: 884-887 T. Fukuda recurrent late onset CAVB 15 years after VSD repair Pediatric Cardiology. 2002; 23: 80-83
Risk of Late Post-Op. AV block Previous transient early post-op CAVB esp. in L-TGA, Down syndrome patients Post-op His-Purkinje conduction disturbances suggesting bi- or tri- fascicular damage (i.e., CRBBB and LAFB) Late development of Mobitz II AV block
Junctional Ectopic Tachycardia in Postoperative VSD Incidence: 3.7-6 % Usually self-limiting, but occasional lifethreatening (mortality rate 5 %) Risk factors: Longer cardiopulmonary bypass Higher body temperature & postoperative troponin T Increased use of inotropic agents Mildh et al Euro J Cardio-Thoracic Surgery 2011;39:75-80 Dodge-Khatami et al Euro J Cardio-Thoracic Surgery 2002;21:255-9
Postoperative Junctional Tachycardia Diagnostic criteria: 1) Junctional rhythm 2) Warm-up & cool-down 3) AV dissociation
Postoperative Junctional Tachycardia Therapeutic goal To decrease the tachycardia heart rate thus allow enough ventricular filling time to achieve adequate stroke volume and maintain blood pressure.
Postoperative Junctional Tachycardia Management Removal exacerbating factors Medical treatment Digoxin, Procainamide, Flecainide, Propafenone, Amiodarone (1 st line) Hypothermia therapy (32-34 0 C) Overdrive atrial pacing ( HR < 210 bpm) Paired Ventricular Pacing
When the rate of tachycardia is slowed down (210 bpm) overdrive atrial pacing can be applied to further augment the blood pressure (left side). The blood pressure is lower when the atrial pacing is discontinued (right side).
At higher heart rate tachycardia (250 bpm) paired ventricular pacing is utilized to augment the blood pressure (left side). The blood pressure drops immediately upon discontinuation of pacing (right side). S1 S2 S1 S2 S1 S2 S1 S2 S1 S2
Paired Ventricular Pacing for Postoperative Junctional Tachycardia 1. Set pacing stimulator to deliver a single S 1 followed by a single S 2. 2. Set initial S 1 S 1 = two times the tachycardia cycle length. 3. Set initial S 1 S 2 = tachycardia cycle length and decrease gradually till ventricular capture without mechanical contraction occurs (confirmed by arterial blood pressure tracing). 4. Decrease S 1 S 1 to make S 2 S 1 as long as possible without breakthrough of tachycardia. Young ML et al PACE 1999; 706-710
8M/O, VSD type 2 s/p trans-atrial repair AF with 3:1 conduction P P P P P P P After 2 days digoxin & propafenone therapy
Conclusion Most arrhythmias after VSD repair are transient, but if without appropriate therapy, they can increase the surgical morbidity and mortality Down syndrome patients with VSD have higher risk to get early CAVB and late onset heart block post-surgical VSD repair
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