Radiofrequency catheter ablation for dyssynchrony-induced dilated cardiomyopathy in an infant

Case Report: Ventricular preexcitation-induced dilated cardiomyopathy improved by the pharmacologic suppression of ventricular preexcitation in three infants, and literature review

The therapy of ventricular preexcitation-induced dilated cardiomyopathy in very small infants or infants with a high risk of ablation is tough and related articles are rare. Effective pharmacotherapy to suppress ventricular preexcitation is valuable.

Aims

To evaluate the effectiveness and safety of pharmacotherapy for cardiac resynchronization in infants with ventricular preexcitation-induced dilated cardiomyopathy.

Methods and results

Three infants with ventricular preexcitation-induced dilated cardiomyopathy, due to the disappearance of ventricular preexcitation during the placement of catheter, intermittent WPW pattern, and right mid septal accessory pathway respectively, had received pharmacotherapy for cardiac resynchronization. The initial dosage of oral amiodarone was 5 mg/kg.d and it was followed by the maintenance dosage of 2-2.5 mg/kg.d 4 weeks later. Propafenone (15 mg/kg.d) served as a supplement since amiodarone was not adequate in case 3. The three infants achieved successful pharmacologic suppression of ventricular preexcitation 10, 6.5, and 4.5 weeks after the initiation of amiodarone respectively. They all got normalized contraction of interventricular septum and LVEF as well as reduced LVEDD gradually after the disappearance of ventricular preexcitation. No side effects associated with pharmacotherapy happened during the follow-up. Amiodarone had been withdrawn for 2 years and 5 months in Cases 1 and 2. They both remained free from ventricular preexcitation and retained normal LVEF and LVEDD.

Conclusions

Pharmacotherapy for cardiac resynchronization with oral amiodarone or in combination with propafenone for infants with ventricular preexcitation-induced dilated cardiomyopathy is effective and safe. Pharmacotherapy for cardiac resynchronization served as another therapeutic choice besides ablation.

Analysis of the influencing factors associated with dyssynchrony and cardiac dysfunction in children with ventricular pre-excitation

OBJECTIVE

To investigate the correlation between ventricular pre-excitation-related dyssynchrony, on cardiac dysfunction, and recovery.

METHODS AND RESULTS

This study included 76 children (39 boys and 37 girls) with a median age of 5.25 (2.67-10.75) years. The patients with pre-excitation-related cardiac dysfunction (cardiac dysfunction group, n = 34) had a longer standard deviation of the time-to-peak systolic strain of the left ventricle and larger difference between the maximum and minimum times-to-peak systolic strain than those with a normal cardiac function (normal function group, n = 42) (51.77 ± 24.70 ms versus 33.29 ± 9.48 ms, p < 0.05; 185.82 ± 92.51 ms versus 111.93 ± 34.27 ms, p < 0.05, respectively). The cardiac dysfunction group had a maximum time-to-peak systolic strain at the basal segments of the anterior and posterior septa and the normal function group at the basal segments of anterolateral and posterolateral walls. The prevalence of ventricular septal dyssynchrony in the cardiac dysfunction group was significantly higher than that in the normal function group (94.1% (32/34) versus 7.7% (3/42), p < 0.05). The patients with ventricular septal dyssynchrony (n = 35) had a significantly higher prevalence of intra-left ventricular systolic dyssynchrony than those with ventricular septal synchrony (n = 41) (57.1% (20/35) versus 14.6% (6/41), p < 0.05). During follow-up after pathway ablation, the patients who recovered from intra-left ventricular dyssynchrony (n = 29) had a shorter left ventricular ejection fraction recovery time than those who did not (n = 5) (χ² = 5.94, p < 0.05). Among the patients who recovered, 93.1% (27/29) had a normalised standard deviation of the time-to-peak systolic strain and difference between the maximum and minimum times-to-peak systolic strain within 1 month after ablation.

CONCLUSION

Ventricular pre-excitation may cause ventricular septal dyssynchrony; thus, attention must be paid to intra-left ventricular dyssynchrony and cardiac dysfunction. Whether intra-left ventricular systolic dyssynchrony can resolve within 1 month may be a new early predictor of patient prognosis.

Perspective of preexcitation induced cardiomyopathy; early septal contraction, and subsequent rebound stretch

BACKGROUND

Preexcitation-induced cardiomyopathy (PIC) is defined as a disease presenting ventricular dyssynchrony because of preexcitation through an accessory pathway (AP), being a cousin of pacing-induced cardiomyopathy. The present review aims at providing perspective of this uncharted subgroup.

METHODS

In order to determine mechanisms and clinical characteristics of PIC, 63 patients in 29 literature reports were reviewed.

RESULTS

A median age at onset was 4 (0.1-59) years; 55 patients (87%) under 18 years old including 16 infants. Twenty patients (32%) experienced supraventricular tachycardia prior and subsequent to the PIC onset. Heart failure and left ventricular (LV) dysfunction did not correlate with other clinical features. All the 65 APs identified (duplicated in 2 patients) were located on the right side of the atrioventricular junction; at the septal area (in 55%) or the anterolateral aspect (in 22%). AP conduction was successfully eliminated by medical or interventional treatments where attempted. LV function returned to normal within 6 months in 67% of patients, while recovery took longer than 3 years in 8%. Frequently seen at the basal segments of the interventricular septum were early contraction within the QRS complex, dyskinesis at mid-systole, and aneurysm/bulging or local thinning.

CONCLUSIONS

Several characteristic factors became clear as described above. Rebound stretch following early shortening of the interventricular septum is seemingly the major mechanism of PIC, and thus a right septal or right anterior/anterolateral AP needs attention as a higher risk for PIC.

The Effect of Accessory Pathway Location on Cardiac Function in Adult Patients with Wolff-Parkinson-White Syndrome

Introduction

The relationship between ventricular pre-excitation and left ventricular dysfunction has been described in the absence of sustained supraventricular tachycardia in a series of case reports. However, there have been no systematic studies about the effect of ventricular pre-excitation on cardiac function in adult patients with different accessory pathway locations.

Methods and Results

Patients were divided into four groups based on the type and location of their accessory pathway: septal, right free wall, left free wall, and concealed. N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, electrocardiogram recordings, electrophysiological properties, and transthoracic echocardiographic data (septal-to-posterior wall motion delay (SPWMD) and interventricular mechanical delay (IVMD) indicating intraventricular and interventricular dyssynchrony) were compared before and after successful ablation. Before radiofrequency catheter ablation, left ventricular ejection fraction (LVEF) was significantly lower in patients with septal and right free wall accessory pathways. Within three months after radiofrequency catheter ablation, NT-proBNP levels decreased, left ventricular function improved, and intraventricular left ventricular dyssynchrony disappeared. There was a negative correlation between initial LVEF with initial QRS duration and initial SPWMD. Notably, SPWMD had a stronger correlation with LVEF than initial QRS duration.

Conclusions

Anterograde conduction with a septal or right free wall accessory pathway may cause left ventricular dyssynchrony and impair left ventricular function. Intraventricular left ventricular dyssynchrony seems to be responsible for the pathogenesis of left ventricular dysfunction. Radiofrequency catheter ablation results in decreased NT-proBNP levels, normalized QRS duration, mechanical resynchronization, and improved left ventricular function.

Dyssynchrony Induced by Ventricular Preexcitation: A Risk Factor for the Development of Dilated Cardiomyopathy

Background: Significant left ventricular dysfunction may arise in right-sided accessory pathways with ventricular preexcitation in the absence of recurrent or incessant tachycardia. This has just been realized and not enough attention has been paid to it.Methods: In the last 7 years, we identified 12 consecutive children with a diagnosis of ventricular preexcitation‐induced dilated cardiomyopathy. This report describes the clinical and echocardiographic characteristics of the patients before and after ablation.Results: Dyssynchronous ventricular contraction was observed by M-mode echocardiography and two-dimensional strain analysis in all patients. The basal and middle segments of the interventricular septum became thin and moved similarly to an aneurysm, with typical bulging during the end of systole. The locations of the accessory pathways were the right-sided septum (n=5) and the free wall (n=7). Left ventricular synchrony was obtained shortly after ablation. The left ventricular function recovered to normal and the left ventricular end-diastolic diameter decreased gradually during follow-up.Conclusions: A causal relationship between ventricular preexcitation and the development of dilated cardiomyopathy is supported by the complete recovery of left ventricular function and reversed left ventricular remodeling after the loss of ventricular preexcitation. Preexcitation-related dyssynchrony was thought to be the crucial mechanism. Ventricular preexcitation‐induced dilated cardiomyopathy is an indication for ablation with a good prognosis.

Pre-excitation cardiac problems in children: recognition and treatment

The prevalence of ventricular pre-excitation is 0.07-0.2% in the pediatric population. Kent bundle is the most common atrioventricular accessory pathway and Mahaim fiber is relatively rare. Approximately, 30-60% of children with ventricular pre-excitation have onset of atrioventricular reentrant tachycardia. Persistent atrioventricular reentrant tachycardia can lead to tachycardiomyopathy. The anterograde conduction of right accessory pathway might lead to ventricular systolic dyssynchrony which might result in cardiac dysfunction even in patients with no tachycardia onset. This type of dilated cardiomyopathy was named as accessory pathway-induced dilated cardiomyopathy. Antiarrhythmic drugs can be used to acutely terminate tachycardia or taken orally to decrease tachycardia recurrence in the long term. However, antiarrhythmic drugs that can be chosen for children are quite limited. Sotalol has become a new choice. With the maturation of radiofrequency catheter ablation technique, progress in three-dimensional electro-anatomic mapping, use of cryoablation, and accumulation of experience in children with small age and weight, catheter ablation has become the first choice for children with pre-excitation syndrome.Conclusion: For ventricular pre-excitation co-exists with dilated cardiomyopathy, differential diagnosis of tachycardiomyopathy or accessory pathway-induced dilated cardiomyopathy should be considered. Catheter ablation (radiofrequency and cryoablation) is a relatively safe and effective treatment option and has become the first choice to treat children with ventricular pre-excitation. What is Known: • Persistent atrioventricular reentrant tachycardia in children can lead to tachycardiomyopathy; • Antiarrhythmic drugs that can be chosen for children are quite limited. What is New: • The anterograde conduction of right accessory pathway (not related to supraventricular tachycardia) might lead to accessory pathway-induced dilated cardiomyopathy. • Catheter ablation (including radiofrequency and cryoablation) has become the first choice for children with pre-excitation syndrome.

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

Recently, cases of pharmacological resynchronization for Wolff-Parkinson-White syndrome (WPWS) in children with left ventricular dyssynchrony (LVD) were reported, but an appropriate pharmacological therapy has not yet been established. A 3-month-old, previously healthy female patient was referred to our hospital due to supraventricular tachycardia (SVT). After resolution of the SVT, 12-lead electrocardiography (ECG) showed ventricular pre-excitation. Transthoracic echocardiography showed LVD with no findings of congenital heart disease or cardiomyopathy. To prevent SVT recurrence, oral propranolol administration was started, but the SVT recurred one month later. To prevent further recurrences, oral flecainide administration was started, as the patient's body weight was insufficient for catheter ablation to be performed safely. When the flecainide dosage was increased to 50 mg/m²/day, the pre-excitation resolved, and the LVD improved. Holter ECG showed that the resolution of pre-excitation depended on the serum concentration of flecainide. There are only few reports on pharmacological resynchronization in WPWS patients with LVD (LVD-WPWS). The present report is the first to examine the efficacy of flecainide in patients with recurrent SVT. Flecainide may be a safe and effective alternative resynchronization therapy for LVD-WPWS patients, especially for children in whom catheter ablation cannot be performed safely due to insufficient body weight. <Learning objective: While cases of pharmacological resynchronization for Wolff-Parkinson-White syndrome (WPWS) in children with left ventricular dyssynchrony (LVD) have been reported, an appropriate pharmacological therapy has yet to be established. Flecainide may be a safe and effective alternative resynchronization therapy for WPWS with LVD, especially for children in whom catheter ablation cannot be performed safely due to insufficient body weight.>.

Hazards of ventricular pre-excitation to left ventricular systolic function and ventricular wall motion in children: analysis of 25 cases

AimThe aim was to attach importance to the hazards of ventricular pre-excitation on left ventricular systolic function and size. METHOD: We analysed the clinical, electrophysiological, and echocardiographic characteristics of the 25 cases with abnormal ventricular wall motion, left ventricular systolic dysfunction, or dilation with co-existing right-sided overt accessary pathways before and after ablation or medication during March 2011 and June 2017. Moreover, we compared the therapy effect between patients with ventricular pre-excitation-induced dilated cardiomyopathy and idiopathic dilated cardiomyopathy without ventricular pre-excitation.ResultAbnormal ventricular wall motion was demonstrated using M-mode echocardiography in 23 cases. The basal segments of the interventricular septum became thin and moved similarly to an aneurysm with typical bulging during end-systole, which was observed in 16 cases. Dilated cardiomyopathy was diagnosed in 14 cases. A total of 23 patients underwent successful ablations and received medications, and the other two patients received only oral medications because of young age. The prognosis of pre-excitation-induced dilated cardiomyopathy is better than idiopathic dilated cardiomyopathy. All the cases with abnormal ventricular wall motion demonstrated recovery of normal left ventricular ejection fraction and decreased left ventricular end-diastolic diameter through ablation. CONCLUSION: Ventricular pre-excitation caused by right-sided accessory pathways may result in abnormal ventricular wall motion, left ventricular systolic dysfunction, dilation, and even dilated cardiomyopathy. In some cases with dilated cardiomyopathy, ventricular pre-excitation may not be the cause of disease but a harmful factor which hampered the recovering of left ventricular systolic function. These conditions are indications for ablation with good prognosis.

Accessory pathway-related left ventricular wall motion abnormality and the effects of radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome

INTRODUCTION

The objective of the current study was to elucidate the effects of the accessory pathways (APs) on the left ventricular (LV) wall motion and radiofrequency catheter ablation (RFCA) on AP-related regional wall motion abnormality (RWMA) in patients with Wolff-Parkinson-White (WPW) syndrome.

METHODS AND RESULTS

We included 348 consecutive patients (age, 37.6 ± 17.3 years; men, 58.3%) with WPW syndrome who underwent RFCA for AP. We analyzed electrocardiographic data, the AP location, LV ejection fraction (LVEF), and RWMA patterns and their changes after RFCA. The locations of APs were right, septal, and left in 78, 94, and 176 patients, respectively. RWMA at the AP location (44.9%, 51.1%, and 17.6%, respectively; P < 0.001), decreased LVEF (10.3%, 6.4%, and 1.1%, respectively; P = 0.004), and dyskinesia (16.7%, 16.0%, and 1.1%, respectively; P < 0.001) were significantly more frequent in patients with a right or septal AP than in those with a left AP. In 31 of 50 patients with RWMA who underwent post-RFCA echocardiography (62.0%), RWMA was completely improved after RFCA. Right AP (odds ratio [OR], 22.084; 95% confidence interval [CI], 3.628-134.420; P = 0.001) and dyskinesia (OR, 6.275; 95% CI, 1.186-33.213; P = 0.031) were significantly associated with the absence of RWMA improvement after RFCA.

CONCLUSIONS

AP-related RWMA is frequent in patients with right or septal APs. A substantial number of patients with right AP or dyskinesia may show no improvement in RWMA after RFCA.

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

Some asymptomatic patients with Wolff-Parkinson-White syndrome have severe left ventricular dyssynchrony and dysfunction. We describe a patient who was given a diagnosis of Wolff-Parkinson-White syndrome in infancy and had a complete response to pharmacologic therapy with flecainide. Our findings suggest that flecainide is a suitable resynchronisation therapy for such infants.