Po-01-011 effect of transvenous systemic right ventricular pacing for heart failure in addition to managing arrhythmias in the patient with unrepaired d-tga

Survival of dextro-transposition of the great arteries (d-TGA) patients is dismal without a surgical repair. Even after the repair, arrhythmias and heart failure (HF) are common in adult patients with a systemic right ventricle (S-RV). N/A N/A Case: A 60-year-old woman with an unrepaired d-TGA, atrial septal defect (ASD), and partial anomalous pulmonary venous return was admitted to our institute due to syncope and heart failure (HF) caused by repetitive atrial tachycardia (AT) recurrences after radiofrequency catheter ablation (RFCA). In a previous session, while the clinical AT was successfully ablated in the right atrium (RA), multiple ATs were still inducible, and it was difficult to control all ATs by RFCA. Further, sinus node dysfunction was observed. Therefore, a pacemaker implantation (PMI) and antiarrhythmic drug therapy were considered the better choice. An epicardial lead was considered to avoid thromboembolic events due to a bidirectional shunt via the ASD. However, her complex hemodynamics concomitant with severe S-RV dysfunction and tricuspid regurgitation (TR) were intolerable for a surgical approach. Therefore, a transvenous PMI was chosen after receiving informed consent. Before the implantation, a pacing study was performed. The ECG at the baseline had a wide QRS duration (QRSD=170ms) with right bundle branch block. Left ventricular (LV) septal pacing using an electrode catheter via the ASD increased the QRSD (180ms) and caused significant S-RV dyssynchrony and worsening TR. Contrarily, S-RV pacing decreased the QRSD (120ms) and preserved the S-RV contraction synchrony suggesting it was the appropriate pacing site. A transvenous DDD PMI was performed under local anesthesia and systemic sedation. A stylet-driven lead could not be inserted into the S-RV because of a huge RA. After all, a thin lumenless lead (SelectSecureR) was implanted on the S-RV septum using a guiding sheath. The stroke volume measured by non-invasive electrical cardiometry (AesculonR) was the best during S-RV paced fusion beats with a 220ms atrioventricular delay. No S-RV dyssynchrony was observed, and the systolic function improved. The ATs were suppressed after amiodarone. She had no syncope, and her HF improved (NYHA class IV→II) after discharge. No thromboembolic events occurred after taking apixaban. S-RV endocardial pacing in an unrepaired d-TGA patient was effective for re-synchronization and improved the HF in addition to managing arrhythmias.