Pharmacologic Cardiac Resynchronization of a 1-Year-Old Boy With Severe Left Ventricular Dysfunction

Abstract

Postero-septal accessory pathways (AP) are a rare cause of intraventricular dyssynchrony and severe LV dysfunction in children. Beside the common treatment with radiofrequency ablation of septal substrates we present the case of a successful pharmacologic resynchronization in a 13/12 years old male toddler with Wolff-Parkinson-White syndrome (WPW) and severe LV dysfunction (left ventricular biplane EF of 31 %) due to intraventricular dyssynchrony with septal to posterior wall motion delay (SPWMD) of 350 ms. Interventricular mechanical delay (IVMD) was 65 ms. Using propafenone, pharmacologic cardiac resynchronization could be achieved. Pharmacologic resynchronization should be considered as safe and effective alternative to catheter ablation in very young children.

Flecainide improves cardiac synchronization in an early infant with Wolff–Parkinson–White syndrome with left ventricular dyssynchrony

“…The appropriate pharmacological therapy for LVD in WPWS children has not been established. To our knowledge, nine past cases were treated with pharmacological resynchronization for LVD-WPWS [2][3][4][5][6][7][8][9]. In these nine cases, the patients' age ranged from 0 days to 8 years (mean: 5 months); eight patients had LV enlargement (no data in remaining one case), and six patients had taken antiheart failure drugs.…”

Pharmacologic therapy with flecainide for asymptomatic Wolff–Parkinson–White syndrome in an infant with severe left ventricular dyssynchrony

“…To our knowledge, similar cases have rarely been diagnosed in infants, and only eight cases have been reported previously (Table 1). 2 – 5 , 7 , 8 In these patients, a long time elapsed between the diagnosis of left ventricular dyssynchrony and the initiation of resynchronisation therapy, such as catheter ablation and pharmacologic treatment. Some of the patients received anti-failure therapy with diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, and digoxin before resynchronisation therapy began, but all patients poorly responded to treatment.…”

“…several recent studies. [1][2][3][4][5] In these studies, right-sided septal accessory pathway was recognised as the main cause of left ventricular dyssynchrony. 1,2 In our patient, the vector of the delta wave on 12-lead electrocardiogram suggested involvement of a right anteroseptal pathway.…”

“…All of these patients responded to treatment, and normal left ventricular function was completely restored within several months or several years. 4,5,7 Flecainide has stronger negative inotropic activity, but is more effective than other sodium-channel blockers for conduction block of accessory pathway associated with Wolff-Parkinson-White syndrome in children. When we treat supraventricular tachycardia with poor responses to pharmacologic treatment with ATP or Ca channel blocker, which suppress atrio-ventricular conduction, we often use Na channel blocker such as flecainide in order to suppress accessory pathway directly.…”

“…Ventricular pre-excitation through an accessory pathway causes intraventricular dyssynchrony and left ventricular dysfunction. [1][2][3][4][5] Catheter ablation of the accessory pathway has been recognised to be an effective therapy that improves dyssynchrony and left ventricular function in older children. 1,2 However, catheter ablation performed for any reason in low-body-weight infants carries a very high risk.…”