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

2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

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.

Asymptomatic Wolff-Parkinson-White Syndrome: An Ounce of Prevention Is Worth the Risk of Cure

PURPOSE OF REVIEW

With increased electrocardiogram screening, asymptomatic preexcitation has become more prevalent. Historically, the asymptomatic-symptomatic dichotomy has directed management. This approach warrants scrutiny, as asymptomatic Wolff-Parkinson-White (WPW) syndrome is not without risk. Children may be unreliable symptom reporters, have atypical arrhythmia symptoms, yet have years to become symptomatic.

RECENT FINDINGS

In a large WPW study, symptomatic patients were more likely to undergo ablation than asymptomatic patients, yet, except for symptoms, there were no differences in clinical or electrophysiology study (EPS) characteristics. Present data confirm real risk in asymptomatic WPW-sudden death can be the first symptom. Although malignant arrhythmias correlate better with EPS risk stratification than with symptoms, EPS data are imperfect predictors. Unlike adults with WPW, children have yet to prove survivorship. Asymptomatic children must be treated differently than adults. Sudden death risk is low but front-loaded in the young. An aggressive approach to asymptomatic WPW is warranted in this era of highly successful, low-risk catheter ablations.

Clinical application value of echocardiography in evaluating left ventricular diastolic function in patients with acute pulmonary embolism

OBJECTIVE

To explore the clinical value of echocardiography in the assessment of left ventricular diastolic function in patients with acute pulmonary embolism (APE).

METHODS

APE patients in our hospital from June 2019 to June 2021 were selected as the observation group. They were divided into low-risk group (19 cases), medium-risk group (16 cases) and high-risk group (15 cases). The non-APE people in our hospital during the same period were selected as the control group. All subjects underwent echocardiography to observe the performance of APE patients under echocardiography. The peak velocity ratio S-wave/D-wave (S/D), early diastolic annular velocity/advanced diastolic annular velocity (Ea/Aa), early filling/early diastolic annular velocity (E/Ea), and early filling/early diastolic annular velocity (E/Ea) were compared with Ar and Vp, respectively; receiver operator characteristic (ROC) curve was used to evaluate the value of echocardiography in evaluating left ventricular diastolic function in patients with APE.

RESULTS

Echocardiography show different manifestations of APE patients. Compared with the control group, S/D, Ea/Aa, and Vp in the observation group were significantly decreased and E/Ea and Ar in the observation group were significantly increased (p < 0.05). With the increase of risk stratification, S/D, Ea/Aa, and Vp gradually decreased, E/Ea and Ar gradually increased, and the difference was statistically significant (p < 0.05). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value, area under curve (AUC), and 95% CI were 89.52%, 65.57%, 72.86%, 80.82%, 75.38%, 0.730, and 0.629-0.831, respectively.

CONCLUSION

Echocardiography can effectively evaluate left ventricular diastolic function in patients with APE, and there are significant differences in left ventricular diastolic function in different risk stratification, which has important reference value for clinical diagnosis and treatment of APE.

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.

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.

Assessment of the physical performance in children with asymptomatic pre-excitation

AIMS

Pre-excitation syndrome can lead to recurrent supraventricular tachycardias (SVTs) and carries a risk of sudden cardiac death (SCD). However, an underestimated consequence of antegrade conduction through an accessory pathway is fusion of intrinsic and accessory conduction that causes asynchronous activation and myocardial contraction that could be a cause for cardiac dysfunction and dilation. It is not known to what extent pre-excitation affects myocardial and physical performance in those patients. The aim of the study was to assess to what degree ventricular pre-excitation affects physical performance in children, using cardio-pulmonary exercise testing (CPET).

METHODS AND RESULTS

The study group consisted of 30 asymptomatic children, aged 8-17 years, with pre-excitation and no history or documentation of SVT compared to 31 healthy controls matched according to sex and age. All patients underwent routine cardiology assessment and then CPET. Echocardiography showed there were no differences in the left ventricular size and function between the study and control group. During the CPET both, patients and controls achieved maximal effort. Patients in the study group showed significantly lower values of VO2max and anaerobic threshold when compared to controls. The most affected subgroup was patients with persistent pre-excitation throughout the exercise.

CONCLUSIONS

Physical performance is affected in children with pre-excitation. This effect is stronger in patients with persistent delta wave observed throughout the exercise.

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.

Ablation of Accessory Pathways with Challenging Anatomy

Although catheter ablation of accessory pathways is deemed highly safe and effective, peculiar location of these pathways might lead to complex and potentially hazardous procedures requiring ablation in anatomic regions such as para-Hisian area, coronary sinus, and epicardial surface. The electrophysiologist should know these possible scenarios to plan the best strategy for safe and effective ablation of these uncommon accessory pathways.

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.

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.

Pré-excitação Ventricular como Causa de Disfunção Ventricular Esquerda Parcialmente Reversível com Ablação da via Anômala

A pré-excitação ventricular é causa rara de cardiomiopatia induzida ou mediada por arritmias. As vias acessórias à direita, especificamente com padrão de bloqueio de ramo esquerdo, podem causar disfunção ventricular pela ativação ventricular anormal resultante da condução anterógrada pela via acessória, por causar dessincronismo atrioventricular, interventricular e intraventricular, com contração assíncrona da parede ventriculare regurgitação mitral. Foi descrita uma paciente assintomática, com eletrocardiograma exibindo pré-excitação ventricular, blo-queio do ramo esquerdo e disfunção ventricular sistólica moderada. Estudo eletrofisiológico demonstrou via acessória de localização anterior e com período refratário anterógrado de 600 ms, realizando-se ablação por radiofrequência com sucesso e significativa melhora da função ventricular.

Ventricular Pre-excitation Causing Left Ventricular Dysfunction Partially Reverted After Ablation of the Accessory Pathway

Ventricular pre-excitation is one of the rarest causes of cardiomyopathy induced or mediated by arrhythmia. Right accessory pathways, specifically with left bundle branch block pattern, can cause ventricular dysfunction, since abnormal ventricular activation resulting from anterograde atrioventricular conduction can cause atrioventricular, interventricular, and intraventricular dyssynchrony, with asynchronous contraction of the ventricular wall and mitral regurgitation. An asymptomatic patient, with ventricular pre-excitation with left bundle branch block and moderate ventricular dysfunction at echocardiography, was described. The electrophysiological study demonstrated an accessory route of anterior location and with an anterograde refractory period of 600 ms, successfully performing radiofrequency ablation and substantial improvement of ventricular function.