Noncompaction cardiomyopathy: The role of advanced multimodality imaging techniques in diagnosis and assessment

Multidisciplinary approach in cardiomyopathies: From genetics to advanced imaging

Cardiomyopathies are myocardial diseases characterized by mechanical and electrical dysfunction of the heart muscle which could lead to heart failure and life-threatening arrhythmias. Certainly, an accurate anamnesis, a meticulous physical examination, and an ECG are cornerstones in raising the diagnostic suspicion. However, cardiovascular imaging techniques are indispensable to diagnose a specific cardiomyopathy, to stratify the risk related to the disease and even to track the response to the therapy. Echocardiography is often the first exam that the patient undergoes, because of its non-invasiveness, wide availability, and cost-effectiveness. Cardiac magnetic resonance imaging allows to integrate and implement the information obtained with the echography. Furthermore, cardiomyopathies' genetic basis has been investigated over the years and the list of genetic mutations deemed potentially pathogenic is expected to grow further. The aim of this review is to show echocardiographic, cardiac magnetic resonance imaging, and genetic features of several cardiomyopathies: dilated cardiomyopathy (DMC), hypertrophic cardiomyopathy (HCM), arrhythmogenic cardiomyopathy (ACM), left ventricular noncompaction cardiomyopathy (LVNC), myocarditis, and takotsubo cardiomyopathy.

Behind Enemy Lines: Vital Echocardiographic Data Prior to Ventricular Arrhythmia Ablation

Ventricular arrhythmias (VA) are a major cause of sudden cardiac death (SCD). Echocardiography is the first widely available imaging tool which guides VA management strategies. Along with other invasive and noninvasive imaging techniques, it provides essential information for identification of VA substrate such as differentiation between ischemic and non-ischemic etiology and identification of structural heart disease. Both classic as well as novel echocardiographic techniques such as left ventricular strain measurement and mechanical dispersion assessment provide prognostic information and assist in risk stratification. Furthermore, intracardiac echocardiography may have an adjunctive role for the VA ablation by providing real-time visualization of cardiac structures, continuous monitoring of catheter location and early recognition of procedural complications. This review gathers all relevant information that echocardiography may offer prior to VA ablation procedures.

Case report: Prenatal diagnosis of fetal non-compaction cardiomyopathy with bradycardia accompanied by de novo CALM2 mutation

We herein report what appears to be the first case of fetal non-compaction cardiomyopathy in both ventricles accompanied by a mutation in the calmodulin gene (CALM2). A 25-year-old woman was referred to our hospital at 25⁺¹ weeks of gestation for evaluation of fetal defects. Prenatal echocardiography showed biventricular non-compaction cardiomyopathy with sinus bradycardia. After termination of the pregnancy, fetal biventricular non-compaction cardiomyopathy was confirmed by autopsy and histopathologic examination. Additionally, whole-exome sequencing of genomic DNA demonstrated a de novo heterozygous mutation (c.389A > G; p.D130G) in CALM2, whereas the parents were normal. In this case report, we highlight the importance of prenatal ultrasound and genetic testing in fetal non-compaction cardiomyopathy with arrhythmia.

Spectrum of Clinical Features and Genetic Profile of Left Ventricular Noncompaction Cardiomyopathy in Children

Background: Left ventricular noncompaction (LVNC) is a genetically determined cardiomyopathy that occurs following a disruption of endomyocardial morphogenesis. The purpose of this study was to identify the clinical characteristics and genetic profile of children with LVNC. Methods: From February 2008 to July 2020, a total of 32 children (median 11.5 years) with LVNC were prospectively enrolled and followed up for a median of 4.02 years. Diagnosis was made based on characteristic features of LVNC in echocardiography and cardiovascular magnetic resonance (CMR). Patients’ clinical symptoms, family history, ECG, Holter ECG, and genetic tests were also evaluated. Results: The most common presenting symptom was heart failure (31% of children). ECG abnormalities were noted in 56% of patients. The most prominent features were ventricular arrhythmias, sinus bradycardia, and paroxysmal third-degree atrioventricular block. Most of the patients (94%) met the criteria for LVNC and CMR confirmed this diagnosis in 82% of cases. The molecular etiology was found in 53% of children. Conclusion: Although heart failure and arrhythmias were very frequent in our study group, thromboembolic events and genetic syndromes were rare. For the accurate and reliable assessment of children with LVNC, it is necessary to get to know their family history and detailed clinical profile.

Left ventricular mechanics and cardiovascular outcomes in non-compaction phenotype

AIMS

This study aims at understanding left ventricular (LV) mechanics of non-compaction (LVNC) phenotype using echocardiographic strain analysis and at assessing the association of functional parameters with cardiovascular (CV) outcomes.

METHODS AND RESULTS

Longitudinal (GLS) and circumferential strain (GCS) as well as rotation of the LV were analyzed in 55 LVNC patients and 55 matched controls. Cardiovascular outcomes were documented for a median follow-up duration of 6 years. GLS and GCS were impaired in LVNC. Similary, regional longitudinal and circumferential strain as well as twist were reduced. CV events occurred in 28 LVNC patients. Apical peak circumferential strain (APCS), peak systolic rotation of apical segments (APSR), and twist were strongly associated with events. This was independent of and incremental to LVEF and non-compacted to compacted myocardial thickness ratio (NC:C ratio). The association of twist with events was also independent of and slightly superior to GLS.

CONCLUSIONS

GLS, GCS, regional strain, and twist were impaired in LVNC. APCS, APSR, and twist exhibited strong association with CV events independent of and incremental to LVEF and NC:C ratio, and in case of twist even GLS. Thus, STE-derived parameters may complement the echocardiographic assessment of LVNC patients in clinical routine.

Left Ventricular Noncompaction: Diagnostic Approach, Prognostic Evaluation, and Management Strategies

Left ventricular noncompaction cardiomyopathy is a heart disease with relevant potential complications including heart failure, life-threatening arrhythmias, and embolic events. In order to prevent adverse outcomes, it is crucial to appropriately recognize and manage this cardiomyopathy. In this paper, we report the main clinical presentations and imaging modalities used for diagnosis, including echocardiography and magnetic resonance imaging. We highlight the role of a comprehensive functional cardiac evaluation and the possible prognostic implications of both systolic and diastolic dysfunction. Furthermore, we summarize clinical factors and imaging findings which have prognostic significance. Finally, we discuss the main management strategies based on phenotypic expressions which are aimed at treating symptoms and preventing complications.

Speckle tracking echocardiography and left ventricular twist mechanics: predictive capabilities for noncompaction cardiomyopathy in the first degree relatives

In non-compaction cardiomyopathy (NCCM), there are several echocardiographic and cardiac magnetic resonance (CMR)-based quantitative diagnostic indices, current criteria mainly placed on morphological features, and none of the diagnostic indices includes left ventricular (LV) function. LV function and hemodynamics could be normal in NCCM patients. Evaluation of left ventricular function at the subclinical stage, strain echocardiographic parameters could be used alternative to standard echocardiographic examinations. The aim of this study to evaluate; NCCM patients, their first-degree relatives, ventricular motion patterns, strain characteristics, and the predictive capabilities of these features for early diagnosis of cardiomyopathy. This cross-sectional, case-control study included 32 NCCM patients, 30 first-degree relatives (father, mother, siblings and children) and 31 healthy volunteers. All patients evaluated with baseline echocardiography, strain measurements, and ventricular wall motion pattern. There were no differences between the groups in terms of age, weight, and body surface area. We observed a statistically significant decrease in ejection fraction (EF), fractional shortening (FS), E/E' and global strain values in patients' relatives compared to healthy volunteers (Patients' relatives: LVEF:60.9 ± 7.2%, FS:0.34 ± 0.07, E/E':7.51 ± 1.83, GLS: - 18.6 ± 3.6, GLSr: - 1.1 ± 0.1, GCS: - 17.1 ± 3.1, GCSr: - 1.2 ± 0.1, GRS:37.1 ± 6.2, GRSr:1.7 ± 0.1; all p values< 0.05). 'Rigid Body Rotation (RBR)' movement pattern was also observed in some of the patient's relative's like in the patients. RBR movement pattern determined patients; EF, longitudinal strain-strain rate, and basal layer rotation values were significantly lower, but radial strain values were higher with the RBR movement pattern (for all values p < 0.05). RBR movement pattern, deterioration of strain parameters, and accompanying echocardiographic features like LVEF, fractional shortening (FS), E/E' in patients' relative groups may contribute to reveal the subclinical status of disease and could be predictive for early diagnosis of cardiomyopathy.

Usefulness of a left ventricular assist device in patients with left ventricular noncompaction

Left ventricular noncompaction (LVNC) is a multifactorial structural abnormality of the myocardial wall characterized by prominent trabeculae and deep trabecular recesses. LVNC may present as a congenital or acquired defect characterized by 2 distinct tissue layers: a spongy, noncompacted inner myocardium and a thin, compacted outer myocardium. Patients with LVNC are prone to thromboembolic events, either due to deep trabeculations in the noncompacted myocardium or due to arrhythmias accompanying the defect. There are sparse data concerning treatment options for patients with LVNC who fail medical management. We present 2 such patients with LVNC who, following failed medical management, received a left ventricular assist device (LVAD): one for long-term management and one as a bridge to transplant. Both were managed successfully without thromboembolic events to date. The success of these cases suggests that LVAD placement is a viable therapy in patients with LVNC as a bridge to transplant or as long-term management.

Auxiliary diagnostic potential of ventricle geometry and late gadolinium enhancement in left ventricular non-compaction; non-randomized case control study

Background

There are still ambiguities existing in regard to left ventricular non-compaction (LVNC) diagnostic imaging. The aim of our study was to analyze diagnostic potential of late gadolinium enhancement (LGE) and ventricle geometry in patients with LVNC and controls.

Methods

Data on cardiac magnetic resonance imaging (CMR) studies for LVNC were reassessed from the hospital’s database (3.75 years; n=1975 exams). Matching sample of controls included cases with no structural heart disease, hypertrophic or dilative cardiomyopathy, arrhythmogenic right ventricular dysplasia or subacute myocarditis. Eccentricity of the left ventricle was measured at end diastole in the region with pronounced NC and maximal to minimal ratio (MaxMinEDDR) was calculated.

Results

Study included 255 patients referred for CMR, 100 (39.2%) with LVNC (prevalence in the studied period 5.01%) and 155 (60.8%) controls. Existing LGE had sensitivity of 52.5% (95%-CI:42.3–62.5), specificity of 80.4% (95%-CI:73.2–86.5) for LVNC, area under curve (AUC) 0.664 (95%-CI:0.603–0.722);p<0.001. MaxMinEDDR>1.10 had sensitivity of 95.0% (95%-CI:88.7–98.4), specificity of 82.6% (95%-CI: 75.7–88.2) for LVNC, AUC 0.917 (95%-CI:0.876–0.948); p<0.001. LGE correlated with Max-Min-EDD-R (Rho=0.130; p=0.038) and there was significant difference in ROC analysis ΔAUC0.244 (95%-CI:0.175–0.314); p<0.001. LGE also correlated negatively with stroke volume and systolic function (both p<0.05, respectively).

Conclusions

LGE was found to be frequently expressed in patients with LVNC, but without sufficient power to be used as a discriminative diagnostic parameter. Both LGE and eccentricity of the left ventricle were found to be relatively solid diagnostic landmarks of complex infrastructural and functional changes within the failing heart.