Left ventricular dysfunction and dilated cardiomyopathy in infants and children with wolff-Parkinson-white syndrome in the absence of tachyarrhythmias

Abnormal conduction-induced cardiomyopathy: a poorly explored entity

A dyssynchronous biventricular activation, which can be determined by left bundle branch block, chronic right ventricular pacing, frequent premature ventricular complexes, or pre-excitation, can cause a global abnormal contractility, thus leading to systolic dysfunction and left ventricular remodelling in a unique nosological entities: abnormal conduction-induced cardiomyopathies. In this clinical scenario, the mainstay therapy is eliminating or improving LV dyssynchrony, removing the trigger. This usually ensures the improvement and even recovery of cardiac geometry and left ventricular function, especially in the absence of genetic background. A multidisciplinary approach, integrating advanced multimodal imaging, is essential for the systematic aetiological definition and the subsequent evaluation and aetiology-guided therapies of patients and their families. This review aims to describe mechanisms, prevalence, risk factors, and diagnostic and therapeutic approach to the various abnormal conduction-induced cardiomyopathies, starting from reasonable certainties and then analysing the grey areas requiring further studies.

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.

Iatrogenic cardiomyopathy in patients with manifest right supero-paraseptal accessory pathways

INTRODUCTION

We describe two patients with right supero-paraseptal accessory pathway (SPAP) who developed left ventricular dysfunction associated with an increased degree of ventricular pre-excitation and frequent orthodromic reciprocating tachycardia (ORT) due to worsening atrioventricular (AV) node conduction.

METHODS AND RESULTS

Case 1: 48-year-old female with a history of normally functioning mechanical mitral valve, CABG, and ventricular pre-excitation that worsened after her open heart surgery. She presented with frequent palpitations with documented supraventricular tachycardia (SVT) and found to have a new left ventricular dysfunction with decrease in left ventricular ejection fraction (LVEF) from 55% to 46% with dyssynchrony. An electrophysiological study confirmed a right SPAP and ORT. The pathway was successfully ablated from the antegrade approach after careful mapping. After ablation and 6-month follow up echocardiogram showed improvement of EF to 54% and the LV dyssynchrony resolved. Case 2: 51-year-old male with a history of frequent SVT with recent unsuccessful ablations that resulted in worsening ventricular pre-excitation, more frequent SVT, and new left ventricular dysfunction (LVEF from 60% to 40%). He was started on amiodarone which resulted in significant sinus bradycardia, intermittent ventricular pre-excitation, and first degree AV block with significant increase in ORT events. His electrophysiology study confirmed SPAP which was successfully ablated from the antegrade approach after careful mapping. After 1 month, follow-up echocardiogram showed an improved ejection fraction to 60%.

CONCLUSION

Left ventricular dysfunction due to dyssynchrony and symptomatic frequent ORT of right SPAP can develop in the setting of new iatrogenic diminished AV node conduction. Successful ablation will result in LV function recovery to baseline.

Abnormal Conduction-Induced Cardiomyopathy: JACC Review Topic of the Week

Nonischemic cardiomyopathies are a frequent occurrence. The understanding of the mechanism(s) and triggers of these cardiomyopathies have led to improvement and even recovery of left ventricular function. Although chronic right ventricular pacing-induced cardiomyopathy has been recognized for many years, left bundle branch block and pre-excitation have been recently identified as potential reversible causes of cardiomyopathy. These cardiomyopathies share a similar abnormal ventricular propagation that can be recognized by a wide QRS duration with left bundle branch block pattern; thus, we coined the term abnormal conduction-induced cardiomyopathies. Such abnormal propagation results in an abnormal contractility that can only be recognized by cardiac imaging as ventricular dyssynchrony. Appropriate diagnosis and treatment will not only lead to improved left ventricular ejection fraction and functional class, but may also reduce morbidity and mortality. This review presents an update of the mechanisms, prevalence, incidence, and risk factors, as well as their diagnosis and management, while highlighting current gaps of knowledge.

Wolff-Parkinson-White syndrome and dilated cardiomyopathy: Not only an electrical issue?

The present case describes a dilated cardiomyopathy associated with both antidromic and orthodromic atrio-ventricular reentrant tachycardias supported by multiple right accessory pathways. Both right accessory pathways were successfully eliminated by catheter ablation and the patient progressively recovered during the follow up. The following etiologies might be involved: 1) primitive dilated cardiomyopathy (or post-inflammatory); 2) septal dyssinchrony due to ventricular pre-excitation; 3) tachycardiomyopathy.

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.

Segmental septal dyskinesia associated with an accessory pathway and preexcitation in two Golden Retriever dogs

Ventricular preexcitation secondary to anterograde conduction through an accessory pathway was diagnosed in two Golden Retriever dogs. Both dogs demonstrated similar segmental myocardial thinning and systolic dyskinesia of the basal interventricular wall on echocardiography. These changes are widely recognised in people with ventricular preexcitation but have not been previously described in dogs. Ventricular preexcitation should be considered as a potential cause for segmental wall motion abnormalities in these two dogs.

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.

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.

Association between severity of cardiac dysfunction caused by ventricular pre-excitation-led dyssynchrony and cardiac function recovery after ablation in children

OBJECTIVE

To investigate the association between the severity of cardiac dysfunction caused by ventricular pre-excitation-led dyssynchrony and cardiac function recovery time after catheter ablation and identify predictors of cardiac function recovery after ablation.

METHODS AND RESULTS

A total of 49 children underwent successful ablation (median 2.92 years). This study included 23 patients with mild cardiac dysfunction (left ventricular ejection fraction [LVEF]: 45% ≤ LVEF ≤ 55%), 15 with moderate (30% ≤ LVEF < 45%), and 11 with severe (LVEF <30%). The time for mean LVEF reaching 55% was 0.75, 3, and more than 12 months, respectively. The mean LVEF of children with severe cardiac dysfunction aged ≤6 years normalized within 12 months of follow-up (63.00% ± 1.41%). Mean LVEF of those aged more than 6 years did not normalize at 12 months of follow-up (38.67% ± 10.97%). LVEF recovery time was significantly different between these two age groups (median 11 months vs >12 months, χ²  = 4.55; P = .04). Cox regression analysis showed that preablation smaller left ventricular diastolic diameter (LVDd) Z score and higher LVEF were predictors of cardiac dysfunction recovery time (hazard ratio [HR] = 0.91, 95% confidence interval [CI] = 0.82-0.99, P = .04; HR = 1.09, 95% CI = 1.03-1.15, P = .01).

CONCLUSION

Patients with higher LVDd Z scores and lower LVEF tend to have slower improvement in cardiac function after ablation. Patients with LVEF less than 30% and aged more than 6 years need more than 12 months to fully recover, and some might not even completely recover. Early catheter ablation is suggested once ventricular pre-excitation-led cardiac dysfunction is suspected.

Improvement in Dyssynchrony with Pharmacological Ablation of Right-Sided Accessory Pathway-Induced Cardiomyopathy in Infants

Right-sided accessary pathways in patients with Wolff-Parkinson-White (WPW) syndrome may cause cardiac dyssynchrony and dilated cardiomyopathy, with a characteristic septal shape, irrespective of any supraventricular tachycardia episodes. We report on two infants (13 and 5 months), whose right-sided accessary pathway-induced dilated cardiomyopathy was successfully treated by flecainide for the first time. After the flecainide administration, an abnormal aneurysmal dilation of the basal interventricular septum was almost restored to normal, and the decreased ejection fraction recovered. Flecainide use may be an important therapeutic option for this entity to avoid catheter ablation during infancy.

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.

Characterisation of three-dimensional mapping in Wolff-Parkinson-White syndrome with septal aneurysmal dyskinesis

A 21-year-old man with Wolff-Parkinson-White syndrome and aneurysmal septal dyskinesis underwent radiofrequency catheter ablation of the accessory pathways. Before radiofrequency catheter ablation, the activation wavefront arose from the aneurysmal septum, whereas the propagation of the left ventricle was normalised after radiofrequency catheter ablation. These findings demonstrate the importance of the electro-mechanical interaction in patients with Wolff-Parkinson-White syndrome and ventricular dysfunction.

Electrocardiographic Preexcitation and Risk of Cardiovascular Morbidity and Mortality: Results From the Copenhagen ECG Study

BACKGROUND

The majority of available data on the clinical course of patients with ventricular preexcitation in the ECG originates from tertiary centers. We aimed to investigate long-term outcomes in individuals from a primary care population with electrocardiographic preexcitation.

METHODS AND RESULTS

Digital ECGs from 328 638 primary care patients were collected during 2001 to 2011. We identified 310 individuals with preexcitation (age range, 8-85 years). Data on medication, comorbidity, and outcomes were collected from Danish nationwide registries. The median follow-up time was 7.4 years (quartiles, 4.6-10.3 years). Compared with the remainder of the population, patients with preexcitation had higher adjusted hazards of atrial fibrillation (hazard ratio [HR], 3.12; 95% confidence interval [CI], 2.07-4.70) and heart failure (HR, 2.11; 95% CI, 1.27-3.50). Subgroup analysis on accessory pathway location revealed a higher adjusted hazard of heart failure for a right anteroseptal accessory pathway (HR, 5.88; 95% CI, 2.63-13.1). There was no evidence of a higher hazard of death among individuals with preexcitation when looking across all age groups (HR, 1.07; 95% CI, 0.68-1.68). However, a statistically significant (P=0.01) interaction analysis (<65 versus ≥65 years) indicated a higher hazard of death for patients with preexcitation ≥65 years (HR, 1.85; 95% CI, 1.07-3.18).

CONCLUSIONS

In this large ECG study, individuals with preexcitation had higher hazards of atrial fibrillation and heart failure. The higher hazard of heart failure seemed to be driven by a right anteroseptal accessory pathway. Among elderly people, we found a statistically significant association between preexcitation and a higher hazard of death.

Concomitant Wolff-Parkinson-White and Atrioventricular Nodal Reentrant Tachycardia: Which Pathway to Ablate?

Patient: Male, 54

Final Diagnosis: WPW and AVNRT

Symptoms: Palpitations • shorthness of breath

Medication: —

Clinical Procedure: EP Study/Radiofrequency Ablation

Specialty: Cardiology

Dyssynchronous ventricular contraction in Wolff-Parkinson-White syndrome: a risk factor for the development of dilated cardiomyopathy

Emerging evidence suggests that significant left ventricular dysfunction may arise in right-sided septal or paraseptal accessory pathways (APs) with Wolff-Parkinson-White syndrome, even in the absence of recurrent or incessant tachycardia. During 1 year and 9 months, we identified four consecutive female children with median age of 8 years diagnosed as having dilated cardiomyopathy (DCM) combined with overt right-sided APs several years ago. Incessant or recurrent tachycardia as the cause of DCM could be excluded. Anti-heart failure chemotherapy did not produce satisfactory effects. The patients underwent radiofrequency ablations (RFCAs). This report describes the clinical and echocardiographic characteristics of the cases before and after the ablation. Dyssynchronous ventricular contraction was observed in all patients. The locations of the APs were the right-sided anteroseptum and the free wall (n = 2 each). All patients received successful RFCAs. Their physical activities and growth improved greatly, and the echocardiographic data demonstrated that their left ventricular (LV) contraction recovered to synchrony shortly after the ablation and that their LV function recovered to normal gradually during the follow-up.

CONCLUSIONS

A causal relationship between overt ventricular preexcitation and the development of DCM is supported by the complete recovery of LV function and reversed LV remodeling after the loss of ventricular preexcitation. Preexcitation-related dyssynchrony was probably the crucial mechanism. Not only right-sided septal or paraseptal but also free wall overt APs may induce LV dysfunction and even DCM. AP-induced DCM is an indication for ablation with a good prognosis.