State-of-the art review: Noncompaction cardiomyopathy in pediatric patients

Pulmonary artery banding for dilated and depressed left ventricle: dilated cardiomyopathy versus left ventricular non-compaction cardiomyopathy

OBJECTIVES

To retrospectively assess the suitability of pulmonary artery banding as a treatment strategy for dilated cardiomyopathy and left ventricular non-compaction cardiomyopathy with depressed left ventricular ejection fraction.

METHODS

The study was retrospective and included consecutive patients who met the inclusion criteria: diagnosed with dilated cardiomyopathy or left ventricular non-compaction cardiomyopathy and left ventricular ejection fraction less than 35%. Cardiac indices were documented, and clinical outcomes were followed for 5 years.

RESULTS

This study included 21 patients with depressed left ventricular ejection fraction due to dilated cardiomyopathy (n = 11) or left ventricular non-compaction cardiomyopathy (n = 10), treated either with anti-congestion medication alone or in combination with pulmonary artery banding. The groups treated with pulmonary artery banding showed significant improvement in left ventricular ejection fraction compared to controls (ANOVA, p = 0.0002), with no major adverse events. In the subgroup with left ventricular non-compaction, pulmonary artery banding led to significant improvement of the left ventricular ejection fraction (p = 0.00002) and significant reductions in the Z scores of left ventricular end-diastolic diameter (p = 0.0002) and of end-diastolic volume (p = 0.004).

CONCLUSIONS

Pulmonary artery banding appears to be a viable strategy for improving heart function in patients with non-compaction and dilated cardiomyopathy and depressed left ventricular ejection fraction. While pulmonary artery banding demonstrated more pronounced benefits in the subgroup with non-compaction cardiomyopathy, significantly enhancing cardiac restoration indices throughout the follow-up period, warranting further investigation in larger studies.

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.

Cardiomyopathy in Children and Adolescents in the Era of Precision Medicine

In childhood and adolescence, cardiomyopathies have their own characteristics and are an important cause of heart failure, arrhythmias, sudden death, and indication for heart transplantation. Diagnosis is a challenge in daily practice due to its varied clinical presentation, heterogeneous etiologies, and limited knowledge of tools related to clinical and molecular genetics. However, it is essential to recognize the different phenotypes and prioritize the search for the etiology. Recent advances in precision medicine have made molecular diagnosis accessible, which makes it possible to individualize therapeutic approaches, stratify the prognosis, and identify individuals in the family who are at risk of developing the disease. The objective of this review is to emphasize the particularities of cardiomyopathies in pediatrics and how the individualized approach impacts the therapy and prognosis of the patient. Through a systematized approach, the five-stage protocol used in our service is presented. These stages bring together clinical evaluation for determining the morphofunctional phenotype, identification of etiology, classification, establishment of prognosis, and the search for personalized therapies.

Exploring the Unknown: Appreciating the Challenges of Non-compaction Cardiomyopathy

Left ventricular non-compaction cardiomyopathy (LVNC), or non-compaction cardiomyopathy (NCCM), is defined by pronounced left ventricular trabeculations and deep intertrabecular recesses connecting with the ventricular cavity. Patients with NCCM can be asymptomatic or have severe complications, including heart failure, arrhythmias, thromboembolism, and sudden cardiac death. Our case discusses a patient with shortness of breath who was found to have a newly decreased ejection fraction. The workup revealed non-ischemic cardiomyopathy and cardiac MRI showed hyper-trabeculations consistent with NCCM. The patient was started on oral anticoagulation and guideline-directed medical therapy (GDMT) and discharged with an event monitor. NCCM stands as a relatively rare and enigmatic condition, often veiled in ambiguity. The absence of standardized diagnostic and management protocols further complicates its clinical landscape. While echocardiography is the primary diagnostic tool, its tendency for under-diagnosis poses a significant challenge. Conversely, advanced imaging modalities like cardiac MRI may lead to instances of overdiagnosis. Treatment approaches are non-specific, incorporating GDMT, anticoagulation, implantable cardioverter-defibrillator placement, and genetic testing paired with counseling. Prioritizing genetic research is crucial to uncover tailored therapeutic interventions. Establishing consensus guidelines and refining diagnostic accuracy are pivotal steps toward mitigating the risks associated with under and over-diagnosis.

RETRACTED: Left Ventricular Non-Compaction in Children: Aetiology and Diagnostic Criteria

Left ventricular non-compaction (LVNC) is a heterogeneous myocardial disorder characterized by prominent trabeculae protruding into the left ventricular lumen and deep intertrabecular recesses. LVNC can manifest in isolation or alongside other heart muscle diseases. Its occurrence among children is rising due to advancements in imaging techniques. The origins of LVNC are diverse, involving both genetic and acquired forms. The clinical manifestation varies greatly, with some cases presenting no symptoms, while others typically manifesting with heart failure, systemic embolism, and arrhythmias. Diagnosis mainly relies on assessing heart structure using imaging tools like echocardiography and cardiac magnetic resonance. However, the absence of a universally agreed-upon standard and limitations in diagnostic criteria have led to ongoing debates in the scientific community regarding the most reliable methods. Further research is crucial to enhance the diagnosis of LVNC, particularly in early life stages.

Prevalence and clinical correlates of ascending aortic dilatation in patients with noncompaction cardiomyopathy

Ascending aortic (AoAsc) dilatation can lead to acute aortic syndromes and has been described in various familial cardiac diseases. Its prevalence and clinical significance in patients with noncompaction cardiomyopathy (NCCM) are however unknown. Establishing the prevalence can facilitate recommendations on routine screening in NCCM. In this cross-sectional cohort study based on the Rijnmond Heart Failure/Cardiomyopathy Registry, the patient were enrolment between 2014 and 2021. All NCCM patients (n = 109) were age and sex matched with 109 dilated cardiomyopathy (DCM) patients as controls. The aortic diameters were measured through the parasternal long-axis transthoracic echocardiographic view at the sinuses of valsalva (SoV-Ao), sinotubular junction (STJ) and ascending aorta (AscAo). Dilatation was defined using published criteria adjusted for body surface area (BSA), sex, and age. Median age of age-sex matched NCCM and DCM patients was 45[31-56] vs. 45 [31-55] years with 53% males in both groups. NCCM patients had more familial hereditary patterns and genetic variants (55% vs. 24%, p < 0.001). DCM patients had more heart failure and left ventricular dysfunction (ejection fraction 34 ± 11 vs. 41 ± 12, p = 0.001). Ascending aortic dilatation was present in 8(7%) patients with NCCM and 5(5%) patients with DCM (p = 0.46). All dilatations were classified as mild. In conclusion, in this cross-sectional cohort study the prevalence of ascending aortic dilatation in NCCM patients was 7%, which were only mild dilatations and not significantly different from an age-sex matched cohort of DCM patients. Routine aortic dilatation screening therefore does not seem warranted in patients with NCCM.

Interplay between Zn2+ Homeostasis and Mitochondrial Functions in Cardiovascular Diseases and Heart Ageing

Zinc plays an important role in cardiomyocytes, where it exists in bound and histochemically reactive labile Zn²⁺ forms. Although Zn²⁺ concentration is under tight control through several Zn²⁺-transporters, its concentration and intracellular distribution may vary during normal cardiac function and pathological conditions, when the protein levels and efficacy of Zn²⁺ transporters can lead to zinc re-distribution among organelles in cardiomyocytes. Such dysregulation of cellular Zn²⁺ homeostasis leads to mitochondrial and ER stresses, and interrupts normal ER/mitochondria cross-talk and mitophagy, which subsequently, result in increased ROS production and dysregulated metabolic function. Besides cardiac structural and functional defects, insufficient Zn²⁺ supply was associated with heart development abnormalities, induction and progression of cardiovascular diseases, resulting in accelerated cardiac ageing. In the present review, we summarize the recently identified connections between cellular and mitochondrial Zn²⁺ homeostasis, ER stress and mitophagy in heart development, excitation–contraction coupling, heart failure and ischemia/reperfusion injury. Additionally, we discuss the role of Zn²⁺ in accelerated heart ageing and ageing-associated rise of mitochondrial ROS and cardiomyocyte dysfunction.

A case with two faces: noncompaction or phospholamban cardiomyopathy?: Noncompaction or phospholamban cardiomyopathy?

Noncompaction cardiomyopathy is a well-known clinical entity, whereas phospholamban gene mutation is a relatively recently known mutation with phenotypes as arrhythmogenic cardiomyopathy and dilated cardiomyopathy. We report the case of a 15-year-old girl that presents with rapid progressive heart failure based on a noncompaction cardiomyopathy as confirmed through cardiovascular imaging. As a result of her progressive heart failure 22 months later she received a heart transplant. Genetic testing showed a phospholamban gene mutation. We present cardiovascular images together with macroscopic and microscopic anatomy. This case shows the importance of considering phospholamban gene mutation in a case of severe noncompaction cardiomyopathy.

Correlation between pathoanatomic findings, imaging modalities, and genetic findings in patients with left ventricular hypertrabeculation/noncompaction

Introduction: Left ventricular hypertrabeculation, also named 'noncompaction' (LVHT) is a cardiac abnormality which is detected by pathoanatomic investigation or during cardiac surgery. Imaging techniques visualize LVHT by ventriculography, echocardiography, cardiac magnetic resonance imaging (CMRI) and computed tomography (CT).Areas covered: We aimed to assess 1) how often the definition of LVHT was validated against a criterion standard, 2) if inter- and intra-observer agreement was assessed, and 3) how often LVHT was associated with genetic diseases. A literature search disclosed 58 cases whose hearts were investigated pathoanatomically and by ≥1 imaging technique. Echocardiography was most frequently (95%) compared with pathoanatomy, followed by cMRI (31%), ventriculography (7%) and CT (5%). Intra- and inter-observer agreement was more frequently assessed for cMRI definitions and yielded more consistent results than for echocardiographic definitions. Since genetic findings were only reported from 4 of the 58 cases, no association with imaging findings could be carried out.Expert opinion: Correlation between pathoanatomic investigations with imaging techniques will hopefully contribute to reliable and uniformly accepted definitions of LVHT. Most probably, the echocardiographic definition of LVHT will be a synthesis of the currently used definitions, integrating short axis and four-chamber views. A refinement of cMRI definitions, considering pathoanatomic and echocardiographic investigations, seems necessary to avoid overdiagnosis.