Successful Permanent Resynchronization for Failing Right Ventricle After Repair of Tetralogy of Fallot

Abstract

A fter repair of tetralogy of Fallot with significantly decreased exercise tolerance, a 17-year-old symptomatic boy underwent successful permanent resynchronization of a failing right ventricle (RV). The patient had surgical repair including pulmonary valvulotomy, infundibulectomy, and pericardial right ventricular outflow tract (RVOT) plasty at 1 year of age. At 3 years of age, he underwent resection of RVOT aneurysm, pulmonary valvuloplasty, and patch enlargement of the left pulmonary artery. Finally, a balloon pulmonary valvuloplasty of a mild residual pulmonary valve stenosis was performed at 17 years of age, resulting in a gradient reduction from 18 to 4 mm Hg and mild (grade I) pulmonary and tricuspid regurgitation. However, the patient continued to show significant RV dilation and systolic/diastolic dysfunction with signs of major RV dyssynchrony (right bundle-branch block; QRS duration of 200 ms and paradoxical interventricular septal motion with a late systolic right to left septal flash) by echocardiography and MRI.1 As a result of reports on successful acute subpulmonary RV resynchronization, 2-4 the patient underwent resynchronization testing in the catheterization laboratory with the aim to identify the RV pacing site associated with maximum acute increase in RV dP/ dt max (from 432 to 624 mm Hg/s) when pacing in complete fusion with spontaneous activation. One month later, an MRIcompatible permanent transvenous dual-chamber pacemaker was implanted, with ventricular pacing lead inserted as close as possible to the previously identified optimal site at the RV free wall (Figure 1), resulting in a Q-RV interval of 140 ms, proving late electric activation of this area. Atrio-ventricular delay was programmed to achieve complete fusion with spontaneous ventricular depolarization, as subsequently confirmed by 24-hour Holter ECG.Six months later, a major decrease in RV size, along with improvement in RV as well as LV function, functional class, and exercise capacity were noted (Table, Figures 2 through 6, and Movies I and II in the online-only Data Supplement). We conclude that permanent resynchronization of a failing RV is an effective method to achieve hemodynamic improvement after repair of tetralogy of Fallot. Patients with right bundle-branch block and significant RV dilation and dysfunction might be considered for this procedure in isolation or along with other indicated surgical or transcatheter interventions. RV electromechanical dyssynchrony may be, in addition to volume overload, a major factor in RV failure development. The precise role and indications for this novel treatment option remain to be studied. This is, to our knowledge, the first report of successful permanent resynchronization of a failing subpulmonary RV in congenital heart disease. Sources of Funding

Impact of surgical pulmonary valve replacement on ventricular strain and synchrony in patients with repaired tetralogy of Fallot: a cardiovascular magnetic resonance feature tracking study

“…Lastly, our data showed that PVR did not lead to a convincing improvement in interventricular synchrony. Thus, for repaired TOF patients in whom interventricular dyssynchrony is thought to be playing a clinically important role, cardiac resynchronization therapy [ 42 ] and not simply PVR, may be needed. Future studies which focus on patients with marked interventricular dyssynchrony who undergo PVR are needed to definitely address this proposition.…”

JCS/JHRS 2019 guideline on non‐pharmacotherapy of cardiac arrhythmias

“…The systemic ventricle is broadly divided into the left ventricle, right ventricle, and single ventricle (single ventricle physiology) 498,500‐506 . In addition, subpulmonary ventricular dyssynchrony must also be considered 507‐511 . A pattern of intraventricular dyssynchrony is observed in the systemic right ventricle or single ventricle physiology, which differs from that of the systemic left ventricle 506 .…”

“… 498 , 500 , 501 , 502 , 503 , 504 , 505 , 506 In addition, subpulmonary ventricular dyssynchrony must also be considered. 507 , 508 , 509 , 510 , 511 A pattern of intraventricular dyssynchrony is observed in the systemic right ventricle or single ventricle physiology, which differs from that of the systemic left ventricle. 506 Moreover, interventricular dyssynchrony in hemodynamics specific to congenital heart disease cannot be ignored.…”

Arrhythmias in adults with congenital heart disease and heart failure

“…These particularities and unique considerations limit the extrapolation of data from trials in patients with acquired heart disease. Nevertheless, encouraging results have been reported from observational studies in patients with heterogeneous forms of CHD, [36][37][38][39][40][41][42][43][44] including systemic right ventricular dysfunction. [45][46][47] In the CHD population that deviates from conventional criteria, the most established indication for CRT is the patient with CCTGA who requires ventricular pacing (Figure 3).…”