Outcomes, arrhythmic burden and ambulatory monitoring of pediatric patients with left ventricular non-compaction and preserved left ventricular function

Determination of Genotype and Phenotypes in Pediatric Patients With Biventricular Noncompaction

BACKGROUND

Left ventricular noncompaction (LVNC) is a hereditary type of cardiomyopathy characterized by prominent trabeculations. Detailed characteristics of biventricular noncompaction (BiVNC) remain unknown. This study aimed to elucidate the clinical characteristics and genetic landscape of BiVNC.

METHODS AND RESULTS

We recruited children with left ventricular noncompaction from Japanese multi-institutional centers from 2013 to 2021. Left ventricular noncompaction was classified as BiVNC, congenital heart disease, arrhythmia, dilated cardiomyopathy, or normal function. In these patients, cardiomyopathy-associated genes were screened. A total of 234 patients (127 male; mean age, 4 months [range, 0-6.6 years]) were enrolled in this study, of whom 25 had BiVNC; 55, normal function; 84, dilated cardiomyopathy; 38, congenital heart disease; and 32, arrhythmia. BiVNC was diagnosed during the perinatal period in 10 patients, in whom the prevalence was higher than that in other patients. A total of 14 patients in the group with BiVNC had congenital heart disease, but not necessarily right heart lesions. Left ventricular dyskinesis was frequently observed in the lateral wall (24%) and apex (28%). Eleven pathogenic variants were found in 11 patients with BiVNC (44.0%). The group with BiVNC had a higher ratio of mitochondrial and developmental gene variants than the other groups. Among all groups, the group with BiVNC had the worst survival rate (P=0.0009).

CONCLUSIONS

Pediatric patients with BiVNC had a high rate of ventricular dyskinesis and poor outcome. A comprehensive and careful screening for disease-causing genes and phenotype may help identify specific patients with left ventricular noncompaction and mortality-related cardiac phenotypes.

Arrhythmias May Hide a Genetic Cardiomyopathy in Left Ventricular Hypertrabeculation in Children: A Single-Center Experience

BACKGROUND

Left ventricular hypertrabeculation (LVHT) is a myocardial disorder with different clinical manifestations, from total absence of symptoms to heart failure, arrhythmias, sudden cardiac death (SCD), and thromboembolic events. It is challenging to distinguish between the benign and pathological forms of LVHT. The aim of this study was to describe the arrhythmic manifestations of LVHT in a large group of pediatric patients and to correlate them with genetic results or other clinical markers.

METHODS

We retrospectively enrolled 140 pediatric patients with diagnosis of LVHT followed at our Institution from 2013 to 2023. Data regarding family history, instrumental exams, cardiac magnetic resonance, genetic testing and outcomes were collected. Most of them had isolated LVHT (80.7%); in other patients, mixed phenotypes (hypertrophic or dilated cardiomyopathy or congenital heart disease) were present.

RESULTS

Arrhythmias were found in 33 children (23.6%): 13 (9.3%) supraventricular tachyarrhythmias; 14 (10%) ventricular arrhythmias (five frequent PVCs (premature ventricular contractions), eight patients with ventricular tachycardia (VT), one ventricular fibrillation (VF)); two (1.4%) sinus node disfunctions; two (1.4%) complete atrio-ventricular blocks (AVB), three (2.1%) paroxysmal complete AVB, one (0.7%) severe I degree AVB. Three patients received an ICD (implantable cardioverter defibrillator). Comparison between LVHT patients with (33 pts) and without (107 pts) arrhythmias as regards genetic testing showed a statistical significance for the presence of class 4 or 5 genetic variants and arrhythmic manifestation (p = 0.037).

CONCLUSIONS

In our pediatric cohort with LVHT, good outcomes were observed, but arrhythmias were not so rare (23.6%); no SCD occurred.

Electrophysiological phenotyping of left ventricular noncompaction cardiomyopathy in pediatric populations: A systematic review

Left ventricular noncompaction cardiomyopathy (LVNC) is a structural heart defect that has been associated with generation of arrhythmias in the population and is a cause of sudden cardiac death with severe systolic dysfunction and fatal arrhythmias. LVNC has gained increasing acknowledgment with increased prevalence. We conducted a systematic review of reported electrocardiogram (ECG) results for pediatric LVNC patients. EMBASE database query was performed, yielding 4531 articles related to LVNC between 1990 and December 2023. Patient age ranged from prenatal to 18 years of age. Qualitative analyses were performed to characterize individual arrhythmias, and summative interpretation of ECG evaluations was gathered for the entire cohort. Systematic review of 57 LVNC cases and ECG presentation revealed many waveform consistencies, including abnormal left ventricular, atrioventricular node, and interventricular septal patterns, and specifically a high incidence of Mobitz type II and Wolff-Parkinson-White waveforms. This review of ECG analysis reinforces the clinical and etiologic significance of pediatric LVNC. While LVNC in pediatric populations may not always present as acute clinical cases, further investigation into the electrophysiology of the disease supports the need for further evaluation and risk stratification for patients with suspected LVNC and/or ventricular arrhythmia.

Advancements in the diagnosis and management of premature ventricular contractions in pediatric patients

Background

Premature ventricular contractions (PVCs) are relatively common arrhythmias in the pediatric population, with implications that range from benign to potentially life-threatening. The management of PVCs in children poses unique challenges, and recent advancements in diagnostic and therapeutic options call for a comprehensive review of current practices.

Methods

This review synthesizes the latest literature on pediatric PVCs, focusing on publications from the past decade. We evaluate studies addressing the epidemiology, pathophysiology, diagnosis, and treatment of PVCs in children, including pharmacological, non-pharmacological, and invasive strategies.

Results

The review identifies key advancements in the non-invasive detection of PVCs, the growing understanding of their genetic underpinnings, and the evolving landscape of management options. We discuss the clinical decision-making process, considering the variable significance of PVCs in different pediatric patient subgroups, and highlight the importance of individualized care. Current guidelines and consensus statements are examined, and areas of controversy or limited evidence are identified.

Conclusions

Our review underscores the need for a nuanced approach to PVCs in children, integrating the latest diagnostic techniques with a tailored therapeutic strategy. We call for further research into long-term outcomes and the development of risk stratification tools to guide treatment. The potential of emerging technologies and the importance of multidisciplinary care are also emphasized to improve prognoses for pediatric patients with PVCs.

Predictors of fatal arrhythmic events in patients with non-compaction cardiomyopathy: a systematic review

Left ventricular non-compaction cardiomyopathy (LVNC) is a congenital heart disease with autosomal dominant inheritance. This review aims to summarize the existing data about the predictors of fatal arrhythmias in patients with LVNC. Medline and Cochrane library databases were searched from inception to November 2021 for articles on LVNC. The reference lists of the relevant research studies as well as the relevant review studies and meta-analyses were also searched. Clinical symptoms and electrocardiogram findings such as left bundle branch block are significantly associated with ventricular arrhythmias. Other non-invasive tools such as Holter monitoring, echocardiography, and cardiac magnetic resonance (CMR) can provide additional value for risk stratification. CMR-derived left and right ventricular ejection fraction, left ventricular end-diastolic diameter, late gadolinium enhancement, and non-compacted to compacted myocardium ratio are predictive of ventricular arrhythmias. An electrophysiological study can provide additional prognostic data in patients with LVNC who are at moderate risk of ventricular arrhythmias. Risk stratification of LVNC patients with no prior history of a fatal arrhythmic event remains challenging. Symptoms assessment, electrocardiogram, Holter monitoring, and cardiac imaging should be performed on every patient, while an electrophysiological study should be performed for moderate-risk patients. Large cohort studies are needed for the construction of score models for arrhythmic risk stratification purposes.

Continuous Arrhythmia Monitoring in Pediatric and Adult Patients With Left Ventricular Noncompaction

Patients with left ventricular noncompaction (LVNC) are at risk of clinically significant arrhythmias and sudden death. We evaluated whether implantable loop recorders could detect significant arrhythmias that might be missed in these patients during annual Holter monitoring. Selected pediatric and adult patients with LVNC who consented to implantable loop recorder placement were monitored for 3 years (study duration, 10 April 2014-9 December 2019). Fourteen subjects were included (age range, 6.5-36.4 yr; 8 males). Of 13 patients who remained after one device extrusion, one underwent implantable cardioverter-defibrillator placement. Four patients (31%) had significant arrhythmias: atrial tachycardia (n=2), nonsustained ventricular tachycardia (n=1), and atrial fibrillation (n=1). All 4 events were clinically asymptomatic and not associated with left ventricular ejection fraction. In addition, a high frequency of benign arrhythmic patterns was detected. Implantable loop recorders enable continuous, long-term detection of important subclinical arrhythmias in selected patients who have LVNC. These devices may prove to be most valuable in patients who have LVNC and moderate or greater ventricular dysfunction.

Hypertrabeculation; a phenotype with Heterogeneous etiology

Left ventricular hypertrabeculation (LVHT) is a phenotype with multiple etiologies and variable clinical presentation and significance. It is characterized by a 2-layer myocardium with an enlarged trabecular layer and a thinner compacted layer. The prevalence has been increasing due to advances in cardiac imaging. Initial attention was focused on the congenital noncompaction syndrome, and the presence of LVHT was always attributed to this etiology. However, due to the lack of consensus diagnostic criteria, LVHT has now been reported in a broad spectrum of cardiomyopathies, congenital heart diseases, monogenetic disorders, neuromuscular diseases, and even healthy individuals. LVHT is often associated with systolic dysfunction, arrhythmias, and thromboembolic events. Given the etiologic heterogeneity, the prognosis and outcomes are primarily determined by comorbidities, and treatment is dictated by known guidelines. We present hypertrabeculation (HT) as a phenotype and discuss the varied landscape in the classification, etiology, diagnosis, and management of the condition.

Sudden Death in the Young: Information for the Primary Care Provider

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Left Ventricular Noncompaction-A Systematic Review of Risk Factors in the Pediatric Population

Left ventricular noncompaction (LVNC) is a heterogeneous, often hereditary group of diseases, which may have diverse clinical manifestations. This article reviews the risk factors for unfavorable outcomes of LVNC in children, as well as discuss the diagnostic methods and the differences between pediatric and adult LVNC. Through a systematic review of the literature, a total of 1983 articles were outlined; 23 of them met the inclusion criteria. In echocardiography the following have been associated with adverse outcomes in children: Left ventricular ejection fraction, end-diastolic dimension, left ventricular posterior wall compaction, and decreased strains. T-wave abnormalities and increased spatial peak QRS-T angle in ECG, as well as arrhythmia, were observed in children at greater risk. Cardiac magnetic resonance is a valuable tool to identify those with systolic dysfunction and late gadolinium enhancement. Genetic testing appears to help identify children at risk, because mutations in particular genes have been associated with worse outcomes. ECG and imaging tests, such as echocardiography and magnetic resonance, help outline risk factors for unfavorable outcomes of LVNC in children and in identifying outpatients who require more attention. Refining the current diagnostic criteria is crucial to avoid inadequate restrain from physical activity.

Increased Burden of Ion Channel Gene Variants Is Related to Distinct Phenotypes in Pediatric Patients With Left Ventricular Noncompaction

BACKGROUND

Left ventricular noncompaction (LVNC) is a hereditary type of cardiomyopathy. Although it is associated with high morbidity and mortality, the related ion channel gene variants in children have not been fully investigated. This study aimed to elucidate the ion channel genetic landscape of LVNC and identify genotype-phenotype correlations in a large Japanese cohort.

METHODS

We enrolled 206 children with LVNC from 2002 to 2017 in Japan. LVNC was classified as follows: LVNC with congenital heart defects, arrhythmia, dilated phenotype, or normal function. In the enrolled patients, 182 genes associated with cardiomyopathy were screened using next-generation sequencing.

RESULTS

We identified 99 pathogenic variants in 40 genes in 87 patients. Of the pathogenic variants, 8.8% were in genes associated with channelopathies, 27% were in sarcomere genes, and 11.5% were in mitochondrial genes. Ion channel gene variants were mostly associated with the arrhythmia classification, whereas sarcomere and mitochondrial gene variants were associated with the dilated phenotype. Echocardiography revealed that the group with ion channel gene variants had almost normal LV ejection fraction and LV diastolic diameter Z scores. Fragmented QRS, old age, and an arrhythmia phenotype were the most significant risk factors for ventricular tachycardia (P=0.165, 0.0428, and 0.0074, respectively). Moreover, the group with ion channel variants exhibited a greater risk of a higher prevalence of arrhythmias such as ventricular tachycardia, rather than congestive heart failure.

CONCLUSIONS

This is the first study that focused on genotype-phenotype correlations in a large pediatric LVNC patient cohort with ion channel gene variants that were determined using next-generation sequencing. Ion channel gene variants were strongly correlated with arrhythmia phenotypes. Genetic testing and phenotype specification allow for appropriate medical management of specific LVNC targets.

Wearable cardioverter-defibrillators in pediatric cardiomyopathy: A cost-utility analysis

BACKGROUND

Dilated cardiomyopathy (DCM) is the most common cardiomyopathy in children. Patients with severe cardiac dysfunction are thought to be at risk of sudden cardiac arrest (SCA). After diagnosis, a period of medical optimization is recommended before permanent implantable cardioverter-defibrillator (ICD) implantation. Wearable cardioverter-defibrillators (WCDs) provide an option for arrhythmia protection as an outpatient during this optimization.

OBJECTIVE

The purpose of this study was to determine the strategy that optimizes cost and survival during medical optimization of a patient with DCM before ICD placement.

METHODS

A Markov state transition model was constructed for the 3 clinical approaches to compare costs, clinical outcomes, and quality of life: (1) "Inpatient," (2) "Home-WCD," and (3) "Home-No WCD." Transitional probabilities, costs, and utility metrics were extracted from the existing literature. Cost-effectiveness was assessed comparing each paradigm's incremental cost-effectiveness ratio against a societal willingness-to-pay threshold of $50,000 per quality-adjusted life year.

RESULTS

The cost-utility analysis illustrated that Home-WCD met the willingness-to-pay threshold with an incremental cost-effectiveness ratio of $20,103 per quality-adjusted life year and 4 mortalities prevented per 100 patients as compared with Home-No WCD. One-way sensitivity analyses demonstrated that Home-No WCD became the most cost-effective solution when the probability of SCA fell below 0.2% per week, the probability of SCA survival with a WCD fell below 9.8%, or the probability of SCA survival with Home-No WCD quadrupled from base-case assumptions.

CONCLUSION

Based on the existing literature probabilities of SCA in pediatric patients with DCM undergoing medical optimization before ICD implantation, sending a patient home with a WCD may be a cost-effective strategy.

A New Diagnosis of Left Ventricular Non-Compaction in a Patient Presenting with Acute Heart Failure

Left ventricular non-compaction is an overall rare cardiomyopathy; however, it is increasingly being recognized with advances in imaging technology. We present the case of a 47-year-old man with new diagnosis of heart failure and left ventricular non-compaction. We review the literature regarding diagnostic imaging criteria and management of this condition.

Frequency of Ventricular Arrhythmias and Other Rhythm Abnormalities in Children and Young Adults With the Marfan Syndrome

Patients with the Marfan syndrome (MFS) are at risk for sudden death. The contribution of arrhythmias is unclear. This study examines the prevalence of arrhythmias in children with the MFS and their relation to clinical and/or echocardiographic factors. Data from the Pediatric Heart Network randomized trial of atenolol versus losartan in MFS were analyzed (6 months to 25 years old, aortic root diameter z-score > 3.0, no previous aortic surgery and/or dissection). Baseline 24-hour ambulatory electrocardiographic monitoring was performed. Significant ventricular ectopy (VE) and supraventricular ectopy (SVE) were defined as ≥10 VE or SVE/hour, or the presence of high-grade ectopy. Three-year composite clinical outcome of death, aortic dissection, or aortic root replacement was analyzed. There were 274 analyzable monitors on unique patients from 11 centers. Twenty subjects (7%) had significant VE, 13 (5%) significant SVE; of these, 2 (1%) had both. None had sustained ventricular or supraventricular tachycardia. VE was independently associated with increasing number of major Ghent criteria (odds ratio [OR] = 2.13/each additional criterion, p = 0.03) and greater left ventricular end-diastolic dimension z-score (OR = 1.47/each 1 unit increase in z-score, p = 0.01). SVE was independently associated with greater aortic sinotubular junction diameter z-score (OR = 1.56/each 1 unit increase in z-score, p = 0.03). The composite clinical outcome (14 events) was not related to VE or SVE (p ≥ 0.3), but was independently related to heart rate variability (higher triangular index). In conclusion, in this cohort, VE and SVE were rare. VE was related to larger BSA-adjusted left ventricular size. Routine ambulatory electrocardiographic monitoring may be useful for risk stratification in select MFS patients.

Adaptation of Radiology Software to Improve Cardiology Results Reporting

Objective: Twenty-four hour ambulatory electrocardiograms (“Holter” monitors) are a key diagnostic test in cardiology. Commercial electronic medical record (EMR) tools have not been designed for pediatric Holter monitor reporting and paper-based methods are inefficient.

Methods: Our tertiary pediatric hospital adapted a radiology EMR tool to a cardiology workflow in order to report Holter monitor results. A retrospective review was performed at 4 time points: prior to intervention, immediately post-intervention, at 6 months and at 12 months post-intervention. The primary outcome variable was time to reporting of Holter findings.

Results: Holter reports were reviewed on 527 studies (patient ages: 1 day to 42 years). The time between the date the patient returned the Holter monitor until the date the referring physician received a final report improved from 19.8 days to 1.5 days (p<0.001). This result was durable over the next 12 months of follow-up. Physician interpretation time improved from 2.1 days to 0.6 days (p=0.01). Transcriptionist time and result scanning time were eliminated (removing 1.9 days and 14 days from the workflow, respectively).

Conclusion: EMR systems are not typically designed for pediatric cardiology, but existing systems can be adapted, yielding important gains for patient care. In specialties like pediatric cardiology, there is insufficient volume nationally to drive development of commercial systems. This study demonstrates the general principle that creative adaptation of EMR systems can improve result reporting in pediatric cardiology and likely in other cardiology practices.

Citation: Webster G, Ward K, Deal BJ, Anderson JB, Tsao S. Adaptation of Radiology Software to Improve Cardiology Results Reporting. Appl Clin Inform 2017; 8: 936–944 https://doi.org/10.4338/ACI-2017-03-RA-0051

A Rare Case of Renal Infarct due to Noncompaction Cardiomyopathy: A Case Report and Literature Review

Left ventricular noncompaction cardiomyopathy is a rare myocardial disorder which results from failure of left ventricle to compact in embryogenesis. We present a case of a 53-year-old female who came because of abdominal pain and was found to have renal infarct secondary to noncompaction cardiomyopathy.

Ambulatory Monitoring and Arrhythmic Outcomes in Pediatric and Adolescent Patients With Duchenne Muscular Dystrophy

BACKGROUND

Patients with Duchenne Muscular Dystrophy (DMD) develop cardiac fibrosis and dilated cardiomyopathy. We described the frequency of significant Holter findings in DMD, the relationship between cardiac function and arrhythmia burden, and the impact of these findings on clinical management.

METHODS AND RESULTS

A retrospective review was done of patients with DMD who received a Holter from 2010 to 2014. Clinical and arrhythmic outcomes were analyzed. Patients were classified based on left ventricular ejection fraction (LVEF): ≥55%, 35% to 54% and <35%. Significant Holter findings included atrial tachycardia, ventricular tachycardia and atrial fibrillation/flutter. Logistic regression was used to assess predictors of significant Holter findings and change in care. The study included 442 Holters in 235 patients. Mean age was 14±4 years. Patients with cardiac dysfunction were older, and had increased late gadolinium enhancement and left ventricular dilation (P<0.01). There were 3 deaths (1%), all with normal function and none cardiac. Patients with LVEF <35% had more arrhythmias including nonsustained atrial tachycardia (P=0.01), frequent premature ventricular contractions, ventricular couplets/triplets, and nonsustained ventricular tachycardia (P<0.001) compared to the other groups. LVEF <35% (P<0.001) was the only predictor of clinically significant Holter finding. Four patients (40%) had change in medication in the LVEF <35% group compared to 9 (3%) in the ≥55% and 4 (4%) in the 35% to 54% groups (P<0.001).

CONCLUSIONS

Sudden cardiac events are rare in DMD patients with an LVEF >35%. Significant Holter findings are rare in patients with DMD who have an LVEF >35%, and cardiac dysfunction appears to predict significant Holter findings. Holter monitoring is highest yield among DMD patients with cardiac dysfunction.