Improvement in non-tachycardia-induced cardiac failure after radiofrequency catheter ablation in a child with a right-sided accessory pathway

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

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.

Deep insight into cardiac dysfunction in children and young adults with Wolff-Parkinson-White syndrome using speckle tracking imaging

Although ventricular pre-excitation via accessory pathways (APs) causes cardiac dysfunction in children and young adults with Wolff-Parkinson-White (WPW) syndrome, the underlying cardiac dysfunction mechanisms are unclear. This study aimed to characterize cardiac dysfunction and clarify sensitive cardiac dysfunction indicators in WPW syndrome patients classified by the APs location with a layer-specific strain analysis. Twenty-four patients with WPW syndrome with a mean age of 14.1 years (6.9-21.6 years) (11 cases: type A with a left-sided AP [WA group], 13 cases: type B with a right-sided AP [WB group]), and 37 age-matched normal controls (N group) were examined. We measured the left ventricle (LV), base-, mid-, and apical-level of circumferential strain (CS), and longitudinal strain (LS) using a layer-specific strain with speckle tracking imaging. Dyssynchrony was also measured based on the timing of the radial strain at each segment. Peak endomyocardial base- and mid-level of CS was lower in both the WA and WB groups compared to the N group. Peak mid-myocardial and epimyocardial base-level of CS and peak mid-myocardial mid-level of CS were lower only in the WB group compared to the N group. Peak LS in all three layers was lower only in the WB group compared to the N group. There was a significant difference between the patient and normal groups for the dyssynchrony index only at the base-level, and there was no significant difference between the groups for LV ejection fraction (EF). Layer-specific strain decreased in more sites in the WB group despite the normal EF value. Layer-specific strains are sensitive indicators for the detection of the early stages of cardiac dysfunction.

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.

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.

Accessory pathway location affects brain natriuretic peptide level in patients with Wolff-Parkinson-White syndrome

PURPOSE

The purpose of this study was to investigate the relationship between the accessory pathway location and brain natriuretic peptide (BNP) level in patients with Wolff-Parkinson-White (WPW) syndrome.

METHODS

We divided 102 WPW syndrome patients with normal left ventricular systolic function into four groups: those with manifest right (MR, n = 14), manifest septal (MS, n = 11), manifest left (ML, n = 30), and concealed (C, n = 47) accessory pathways. BNP level and electrophysiological properties, including difference in timing of the ventricular electrogram between the His bundle area and the distal coronary sinus area (His-CS delay), which indicate intraventricular dyssynchrony, were compared.

RESULTS

BNP levels (pg/dl) were higher in the MR and MS groups than in the ML and C groups (MR, 64 ± 58; MS, 55 ± 45; ML, 17 ± 15; C, 25 ± 21; P < 0.001). AV intervals (ms) were shorter in the MR and MS groups than in the ML and C groups (MR, 76 ± 16; MS, 83 ± 6; ML, 101 ± 19; C, 136 ± 20; P < 0.001). His-CS delay (ms) was longer in the MR group than in the other groups (MR, 50 ± 15; MS, 21 ± 7; ML, 23 ± 10; C, 19 ± 8; P < 0.001). The AV interval (P < 0.01) and the His-CS delay (P < 0.001) were negatively and positively correlated, respectively, with the BNP level.

CONCLUSION

Anterograde conduction with a right or septal accessory pathway increased the BNP level in WPW syndrome patients with normal cardiac function.

Successful control of life-threatening polymorphic ventricular tachycardia by radiofrequency catheter ablation in an infant

We present a case of a 9-month-old girl in whom malignant polymorphic ventricular tachycardia (VT) was successfully controlled by radiofrequency catheter ablation under guidance with a three-dimensional mapping system. The VTs originated from the left ventricular lateral wall, left ventricular anterior wall, and left ventricular apex. At least six types of VTs were documented during the electrophysiology study. All VTs were successfully controlled after two sessions of radiofrequency catheter ablation, and she was discharged from our hospital on propranolol, mexiletine, flecainide, and aprindine.