Reference values for left and right ventricular trabeculation and non-compacted myocardium

Left Ventricular Trabeculations at Cardiac MRI: Reference Ranges and Association with Cardiovascular Risk Factors in UK Biobank

Background The extent of left ventricular (LV) trabeculation and its relationship with cardiovascular (CV) risk factors is unclear. Purpose To apply automated segmentation to UK Biobank cardiac MRI scans to (a) assess the association between individual characteristics and CV risk factors and trabeculated LV mass (LVM) and (b) establish normal reference ranges in a selected group of healthy UK Biobank participants. Materials and Methods In this cross-sectional secondary analysis, prospectively collected data from the UK Biobank (2006 to 2010) were retrospectively analyzed. Automated segmentation of trabeculations was performed using a deep learning algorithm. After excluding individuals with known CV diseases, White adults without CV risk factors (reference group) and those with preexisting CV risk factors (hypertension, hyperlipidemia, diabetes mellitus, or smoking) (exposed group) were compared. Multivariable regression models, adjusted for potential confounders (age, sex, and height), were fitted to evaluate the associations between individual characteristics and CV risk factors and trabeculated LVM. Results Of 43 038 participants (mean age, 64 years ± 8 [SD]; 22 360 women), 28 672 individuals (mean age, 66 years ± 7; 14 918 men) were included in the exposed group, and 7384 individuals (mean age, 60 years ± 7; 4729 women) were included in the reference group. Higher body mass index (BMI) (β = 0.66 [95% CI: 0.63, 0.68]; P < .001), hypertension (β = 0.42 [95% CI: 0.36, 0.48]; P < .001), and higher physical activity level (β = 0.15 [95% CI: 0.12, 0.17]; P < .001) were associated with higher trabeculated LVM. In the reference group, the median trabeculated LVM was 6.3 g (IQR, 4.7-8.5 g) for men and 4.6 g (IQR, 3.4-6.0 g) for women. Median trabeculated LVM decreased with age for men from 6.5 g (IQR, 4.8-8.7 g) at age 45-50 years to 5.9 g (IQR, 4.3-7.8 g) at age 71-80 years (P = .03). Conclusion Higher trabeculated LVM was observed with hypertension, higher BMI, and higher physical activity level. Age- and sex-specific reference ranges of trabeculated LVM in a healthy middle-aged White population were established. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Kawel-Boehm in this issue.

Concealed Inherited Cardiomyopathies Detected in Cardio-Oncology Screening

INTRODUCTION

Basal cardiovascular risk assessment in cardio-oncology is essential. Integrating clinical information, ECG and transthoracic echocardiogram can identify concealed inherited cardiomyopathies (ICMPs) with potential added risk of cardiotoxicity. We aimed to evaluate the impact of our Cardio-Oncology Unit design in detecting concealed ICMPs.

METHODS

We carried out a retrospective study of all consecutive breast cancer patients referred to the Cardio-Oncology Unit for cardiac evaluation (2020-2022). ICMPs diagnosis was provided according to ESC guidelines and underwent genetic testing. ICMPs prevalence in this cohort was compared to the highest and lowest frequency reported in the general population.

RESULTS

Among 591 breast cancer patients, we identified eight patients with ICMPs: one arrhythmogenic cardiomyopathy (ACM), three familial non-ischemic dilated cardiomyopathy (DCM), three hypertrophic cardiomyopathy (HCM) and one left ventricular non-compaction cardiomyopathy (LVNC), which has now been reclassified as non-dilated left ventricular cardiomyopathy. The number of ICMPs identified was within the expected range (neither overdiagnosed nor overlooked): ACM 0.0017 vs. 0.0002-0.001 (p 0.01-0.593); DCM 0.0051 vs. 0.002-0.0051 (p 0.094-0.676); HCM 0.005 vs. 0.0002-0.002 (p < 0.001-0.099); LVCN 0.0017 vs. 0.00014-0.013 (p 0.011-0.015). Genetic testing identified a pathogenic FLNC variant and two pathogenic TTN variants.

CONCLUSION

Opportunistic screening of ICMPs during basal cardiovascular risk assessment can identify high-risk cancer patients who benefit from personalized medicine and enables extension of prevention strategies to all available relatives at concealed high cardiovascular risk.

Characteristics of the right ventricle in left ventricular noncompaction with reduced ejection fraction in the light of dilated cardiomyopathy

BACKGROUND

Reports of left ventricular noncompaction (LVNC) rarely include descriptions of the right ventricle (RV). This study aimed to describe the characteristics of the RV in LVNC patients with reduced LV function (LVNC-R) compared with patients with dilated cardiomyopathy (DCM) and subjects with LVNC with normal left ventricular ejection fraction (LV-EF) (LVNC-N).

METHODS

Forty-four LVNC-R patients, 44 LVNC-N participants, and 31 DCM patients were included in this retrospective study (LV-EF: LVNC-R: 33.4±10.2%; LVNC-N: 65.0±5.9%; DCM: 34.6±7.9%). Each group was divided into two subgroups by the amount of RV trabeculation.

RESULTS

There was no difference in the RV-EF between the groups, and the RV trabecular mass correlated positively with the RV volume and negatively with the RV-EF in all the groups. All the measured parameters were comparable between the groups with decreased LV function. The hypertrabeculated RV subgroups showed significantly higher RV volumes and lower RV-EF only in the decreased-LV-function groups. The correlation of LV and RV trabeculation was observed only in the LVNC-N group, while LV trabeculation correlated with RV volumes in both noncompacted groups. Both decreased-LV-function groups had worse RV strain values than the LVNC-N group; however, RV strain values correlated with RV trabeculation predominantly in the LVNC-R group.

CONCLUSIONS

The presence and characteristics of RV hypertrabeculation and the correlations between LV trabeculation and RV parameters raise the possibility of RV involvement in noncompaction; moreover, RV strain values might be helpful in the early detection of RV function deterioration.

NON-COMPACTION CARDIOMYOPATHY: ISSUES, CONTRADICTIONS AND SEARCH FOR EFFECTIVE DIAGNOSTIC CRITERIA. LITERATURE REVIEW. PART 2

Active research of non-compaction cardiomyopathy (NCM) has been going on for more than 30 years. A significant amount of information has been accumulated that is familiar to a much larger number of specialists than in the most recent past. Despite this, numerous issues remain unresolved, ranging from classification (congenital or acquired, nosology or morphological phenotype) to the ongoing search for clear diagnostic criteria that separate NCM from physiological hypertrabecularity and secondary non-compaction myocardium with the background of existing chronic processes. Meanwhile, a high risk of adverse cardiovascular events in a certain group of people with NCM is quite high. These patients need timely and often quite aggressive therapy. This review of sources of scientific and practical information is devoted to the current aspects of the classification, extremely diverse clinical picture, extremely complex genetic and instrumental diagnosis of NCM, and the possibilities of its treatment. The purpose of this review is to analyze current ideas about the controversial problems of non-compaction cardiomyopathy. The material for its preparation is the numerous sources of databases Web Science, PubMed, Google Scholar, eLIBRARY. As a result of their analysis, the authors tried to identify and summarize the main problems of the NCM and identify the ways to resolve them.

Left ventricular noncompaction: a disorder with genotypic and phenotypic heterogeneity-a narrative review

Background and Objective

Left ventricular noncompaction (LVNC) is a cardiomyopathy characterized by excessive trabecular formation and deep recesses in the ventricular wall, with a bilaminar structure consisting of an endocardial noncompaction layer and an epicardial compacted layer. Although genetic variants have been reported in patients with LVNC, understanding of LVNC and its pathogenesis has not yet been fully elucidated. We addressed the latest findings on genes reported to be associated with LVNC morphogenesis and possible pathologies to understand the diverse spectrum between genotype and phenotype in LVNC. Also, the latest findings and issues related to the diagnosis of LVNC were summarized.

Methods

This article is written as a commentary narrative review and will provide an update on the current literature and available data on common forms of LVNC published in the past 30 years in English through to May 2022 using PubMed.

Key Content and Findings

Familial forms of LVNC are frequent, and autosomal dominant mode of inheritance has been predominantly observed. Several of the candidate causative genes are also mutated in other cardiomyopathies, suggesting a possible shared molecular and/or cellular etiology. The most common gene functions were sarcomere function whereas genes in mice LVNC models were involved in heart development. Echocardiography and cardiac magnetic resonance imaging (CMR) are useful for diagnosis although there are no unified criteria due to overdiagnosis of imaging, poor consistency between techniques, and lack of association between trabecular severity and adverse clinical outcomes.

Conclusions

This review reflects the current lack of clarity regarding the pathogenesis and significance of LVNC and showed the complexity of imaging diagnostic criteria, interpretation of the role of LVNC as a cause, and uncertainty regarding the specific genetic basis of LVNC.

Impact of Right Ventricular Trabeculation on Right Ventricular Function in Patients With Left Ventricular Non-compaction Phenotype

Right ventricular (RV) involvement in left ventricular (LV) non-compaction (LVNC) remains unknown. We aimed to describe the RV volumetric, functional, and strain characteristics and clinical features of patients with LVNC phenotype and good LV ejection fraction (EF) using cardiac magnetic resonance to characterize RV trabeculation in LVNC and to study the relationships of RV and LV trabeculation with RV volume and function. This retrospective study included 100 Caucasian patients with LVNC phenotype and good LV-EF and 100 age- and sex-matched healthy controls. Patients were further divided into two subgroups according to RV indexed trabecular mass [RV-TMi; patients with RV hypertrabeculation (RV-HT) vs. patients with normal RV trabeculation (RV-NT)]. We measured the LV and RV volumetric, functional, and TMi values using threshold-based postprocessing software and the RV and LV strain values using feature tracking and collected the patients' LVNC-related clinical features. Patients had higher RV volumes, lower RV-EF, and worse RV strain values than controls. A total of 22% of patients had RV-TMi values above the reference range; furthermore, RV-HT patients had higher RV and LV volumes, lower RV- and LV-EF, and worse RV strain values than RV-NT patients. We identified a strong positive correlation between RV- and LV-TMi and between RV-TMi and RV volumes and a significant inverse relationship of both RV- and LV-TMi with RV function. The prevalence of LVNC-related clinical features was similar in the RV-HT and RV-NT groups. These results suggest that some patients with LVNC phenotype might have RV non-compaction with subclinical RV dysfunction and without more severe clinical features.

Age- and Sex-Specific Characteristics of Right Ventricular Compacted and Non-compacted Myocardium by Cardiac Magnetic Resonance

The age and sex-specific characteristics of right ventricular compacted (RV-CMi) and RV-trabeculated myocardial mass (RV-TMi) and the determinants of RV myocardium are less well-studied; however, in different conditions, these might provide additional diagnostic information. We aimed to describe the age- and sex-specific characteristics of RV-CMi, RV-TMi, and RV volumetric and functional parameters and investigate the determinants of RV myocardial mass with cardiac magnetic resonance (CMR). Two hundred healthy Caucasian volunteers free of known cardiovascular or systemic diseases were prospectively enrolled in this study. Four different age groups were established with equal numbers of males and females: Group A (n = 50, 20-29 years, mean age: 24.3 ± 3.2 years), Group B (n = 50, 30-39 years, mean age: 33.6 ± 2.6 years), Group C (n = 50, 40-49 years, mean age: 44.7 ± 2.7 years), and Group D (n = 50, ≥50 years, mean age: 55.1 ± 3.9 years). Left ventricular (LV) and RV volumetric, functional, CMi, and TMi values were measured with a threshold-based post-processing CMR method. The volumetric parameters, RV-CMi, and RV-TMi values were larger, and the ejection fraction (EF) was lower in males. The RV-CMi did not correlate with age in either of the sexes, while the RV-TMi decreased with age in females but remained stable in males. The RV-TMi and RV-CMi correlated positively with RV volumetric parameters, the LV-CMi, the LV-TMi, and each other in both sexes. LV-TMi, LV-CMi, RV end-systolic volume, and sex were independent predictors of RV-TMi. Understanding the characteristics of RV-trabeculated and RV-compacted myocardium might have additive value in diagnosing different conditions with RV hypertrophy or hypertrabeculation.

Regional and Temporal Variation of Ventricular and Conduction Tissue Activity During Ventricular Fibrillation in Canines

[Figure: see text].

Sex- and age- specific normal values of left ventricular functional and myocardial mass parameters using threshold-based trabeculae quantification

Background

The threshold-based (TB) trabeculated and papillary muscle mass (TPM) quantification method for cardiac MRI (CMR) calculates different values than conventional contouring techniques. We aimed to identify the sex- and age-related normal reference ranges for left ventricular (LV) myocardial mass values, volumetric and functional parameters and the correspondence of these parameters using the TB method.

Methods

Healthy European adults (n = 200, age: 39.4 ± 12 years, males: 100) were examined with CMR and evaluated with a TB postprocessing method. They were stratified by sex and age (Group A: 18–29, Group B: 30–39, Group C: 40–49, Group D: >50 years). The calculated parameters were indexed to body surface area (i).

Results

The normal reference ranges for the studied parameters were assessed in each age group. Significant biometric differences in LV parameters and mass-to-volume ratios were found between males and females, and the left ventricular compacted myocardial mass (LVCMi) and TPMi differences remained significant after stratification by age. Unlike other LV volumetric and functional parameters and mass-to-volume ratios, the TPMi, the LVCMi and the TPMi-to-LVCMi ratio did not differ among age groups in males or females. This finding was strengthened by the lack of correlation between TPMi and age.

Conclusions

Age- and sex-related normal reference ranges for LV volumetric and functional parameters and LVCMi and TPMi values were established using a TB postprocessing method. TPMi, LVCMi and their ratio did not change over time. The TPMi-to-LVCMi and the mass-to-volume ratios might have clinical utility in the differential diagnosis of conditions with LV hypertrabeculation.

Higher spatial resolution improves the interpretation of the extent of ventricular trabeculation

The ventricular walls of the human heart comprise an outer compact layer and an inner trabecular layer. In the context of an increased pre-test probability, diagnosis left ventricular noncompaction cardiomyopathy is given when the left ventricle is excessively trabeculated in volume (trabecular vol >25% of total LV wall volume) or thickness (trabecular/compact (T/C) >2.3). Here, we investigated whether higher spatial resolution affects the detection of trabeculation and thus the assessment of normal and excessively trabeculated wall morphology. First, we screened left ventricles in 1112 post-natal autopsy hearts. We identified five excessively trabeculated hearts and this low prevalence of excessive trabeculation is in agreement with pathology reports but contrasts the prevalence of approximately 10% of the population found by in vivo non-invasive imaging. Using macroscopy, histology and low- and high-resolution MRI, the five excessively trabeculated hearts were compared with six normal hearts and seven abnormally trabeculated and excessive trabeculation-negative hearts. Some abnormally trabeculated hearts could be considered excessively trabeculated macroscopically because of a trabecular outflow or an excessive number of trabeculations, but they were excessive trabeculation-negative when assessed with MRI-based measurements (T/C <2.3 and vol <25%). The number of detected trabeculations and T/C ratio were positively correlated with higher spatial resolution. Using measurements on high resolution MRI and with histological validation, we could not replicate the correlation between trabeculations of the left and right ventricle that has been previously reported. In conclusion, higher spatial resolution may affect the sensitivity of diagnostic measurements and in addition could allow for novel measurements such as counting of trabeculations.

Left ventricular characteristics of noncompaction phenotype patients with good ejection fraction measured with cardiac magnetic resonance

OBJECTIVE

We describe left ventricular (LV) volumes, myocardial and trabeculated muscle mass and strains with Cardiac magnetic resonance of a large cohort (n=81) who fulfilled the morphologic criteria of left ventricular noncompaction (LVNC) and had good ejection fraction (EF >55%) and compare them with healthy controls (n=81). Male and female patients were compared to matched controls and to each other. We also investigated the LV trabeculated muscle mass cutoff in male and female patients with LVNC.

METHODS

81 participants with LVNC and 81 healthy controls were included. Male and female patients were compared to matched controls and to each other. We also investigated the left ventricular trabeculated muscle mass cut-off in male and female LVNC patients.

RESULTS

The LV parameters of the LVNC population were normal, but they had significantly higher volumes, myocardial and trabeculated muscle mass, and a significantly smaller EF than the controls. Similar differences were observed after stratifying by sex. The optimal LV trabeculated muscle mass cutoffs were 25.8 g/m2 in men (area under the curve: 0.81) and 19.0 g/m2 in women (area under the curve: 0.87). The patients had normal global strains but a significantly worse global circumferential strain (patients vs controls: -29.9±4.9 vs. -35.8±4.7%, p<0.05) and significantly higher circumferential mechanical dispersion than the controls (patients vs. controls: 7.6±4.2 vs. 6.1±2.8%; p<0.05). No disease-related strain differences were noted between men and women.

CONCLUSION

The LV functional and strain characteristics of the LVNC cohort differed significantly from those of healthy participants; this might be caused by increased LV trabeculation, and its clinical relevance might be questionable. The LV trabeculated muscle mass was very different between men and women; thus, the use of sex-specific morphologic diagnostic criteria should be considered.

A systematic review and meta-analysis of the prevalence of left ventricular non-compaction in adults

AIMS

To assess the reported prevalence of left ventricular non-compaction (LVNC) in different adult cohorts, taking in to consideration the role of diagnostic criteria and imaging modalities used.

METHODS AND RESULTS

A systematic review and meta-analysis of studies reporting LVNC prevalence in adults. Studies were sourced from Pre-Medline, Medline, and Embase and assessed for eligibility according to inclusion criteria. Eligible studies provided a prevalence of LVNC in adult populations (≥12 years). Studies were assessed, and data extracted by two independent reviewers. Fifty-nine eligible studies documenting LVNC in 67 unique cohorts were included. The majority of studies were assessed as moderate or high risk of bias. The pooled prevalence estimates for LVNC were consistently higher amongst cohorts diagnosed on cardiac magnetic resonance (CMR) imaging (14.79%, n = 26; I2 = 99.45%) compared with echocardiogram (1.28%, n = 36; I2 = 98.17%). This finding was unchanged when analysis was restricted to studies at low or moderate risk of bias. The prevalence of LVNC varied between disease and population representative cohorts. Athletic cohorts demonstrated high pooled prevalence estimates on echocardiogram (3.16%, n = 5; I2 = 97.37%) and CMR imaging (27.29%, n = 2).

CONCLUSION

Left ventricular non-compaction in adult populations is a poorly defined entity which likely encompasses both physiological adaptation and pathological disease. There is a higher prevalence with the introduction of newer imaging technologies, specifically CMR imaging, which identify LVNC changes more readily. The clinical significance of these findings remains unclear; however, there is significant potential for overdiagnosis, overtreatment, and unnecessary follow-up.

Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

Prevalence and significance of isolated left ventricular non-compaction phenotype in normal black Africans using echocardiography

Background

Several large, prospective screening studies of predominantly Caucasian patients have suggested that hypertrabeculation may not necessarily be pathologic unless there is concomitant left ventricular (LV) dysfunction, LV dilatation, history of arrhythmia, family history, or characteristic gene mutations. This conundrum may be magnified in blacks, in whom hypertrabeculation and LV hypertrophy is more common. We therefore investigated the frequency of hypertrabeculation/isolated LV noncompaction (ILVNC) phenotype in normal black Africans and evaluated LV function using sensitive measures of deformation and twist.

Methods

Two hundred and fifty-three volunteers were recruited and evaluated according to strict inclusion and exclusion criteria. Their mean age was 36.3 ± 12.2 years.

Results

Trabeculations were found in 12 (4.74%) participants. Three (1.2%) subjects had ≥ 4 LV trabeculations. The LV apex was the most common anatomical site for the location of trabeculations. Subjects with trabeculations were more likely to be males of a younger age, and had greater LV end-diastolic and end-systolic parameters and lateral e’. However, 0.8% of the population fulfilled the Stollberger criteria, and none fulfilled the Jenni, Milwaukee, or Baragwanath criteria. All subjects in this study had normal rotation patterns with no differences in rotational parameters or net twist.

Conclusions

Trabeculations may be found as a normal variant in black Africans. Assessing trabeculations alone may infer ILVNC; however, utilizing the more comprehensive ILVNC criteria enables differentiation of a possible LVNC phenotype. Normal individuals with hypertrabeculation have normal LV function and normal rotation patterns, with no differences in rotational parameters or net twist.

Left-ventricular non-compaction-comparison between different techniques of quantification of trabeculations: Should the diagnostic thresholds be modified?

BACKGROUND

Diagnosis of left ventricular non-compaction (LVNC) is challenging, and different imaging techniques propose different criteria.

AIM

To compare the value of two-dimensional transthoracic echocardiography (2D-TTE) and cardiac magnetic resonance (CMR) criteria in diagnosing LVNC, and to test a new trabecular quantification method obtained by 2D-TTE, exploring its relationship with CMR non-compacted mass quantification.

METHODS

From a multicentre French study, we selected 48 patients with LVNC and 20 with dilated cardiomyopathy (DCM) who underwent 2D-TTE and CMR. Current 2D-TTE (Jenni et al.) and CMR criteria (Petersen et al., Jacquier et al.), were tested. A new 2D-TTE method of trabecular quantification (percentage of trabecular area) was also proposed, and compared with current criteria.

RESULTS

The best cut-off values for the diagnosis of LVNC were a non-compacted/compacted ratio≥2.3 (Petersen et al.), a trabeculated left ventricular mass≥20% (Jacquier et al.) and a non-compacted/compacted ratio≥1.8 (Jenni et al.). Lowering the threshold for the criterion of Jenni et al. from>2 to ≥1.8 improved its sensitivity from 69% to 98%. The 2D-TTE percentage of trabecular area was 25.9±8% in the LVNC group vs. 9.9±4.4% in the DCM group (P<0.05), and was well correlated with CMR non-compacted mass (r=0.65; P<0.05). A 15.8% threshold value for 2D-TTE percentage of trabecular area predicted LVNC diagnosis with a specificity of 95% and a sensitivity of 92%; its sensitivity was better than that for the criteria of Jenni et al. (P<0.01) and Petersen et al. (P=0.03).

CONCLUSIONS

Revision of the current threshold for the criterion of Jenni et al. from>2 to ≥1.8 is necessary to improve LVNC diagnosis in patients with left ventricular dysfunction. A new 2D-TTE trabecular quantification method improves TTE diagnosis of LVNC.

Left ventricular noncompaction: a distinct cardiomyopathy or a composite anatomical syndrome?

Left ventricular non-compaction (LVNC) is characterized by hypertrabecularity (thickened non-compact layer) with deep intertrabecular recesses that are continuous with the ventricle cavity, and a thin compact layer. The phenotypes of LVNС are extremely variable: the left or right ventricular variant, biventricular form, LVNC with symptoms of heart failure or arrhythmia, asymptomatic forms or variants with thromboembolic events. In 30-50 % of patients with LVNC genetic mutations of genes encoding sarcomeric or cytoskeletal proteins are revealed by a genetic study. The article presents a literature review on the problems of diagnosis, visualization, pathogenesis, variability of clinical manifestations of LVNC and its genetic heterogeneity. Clinical cases demonstrating LVNC as a concomitant anatomical syndrome due to monogenic Danone disease, as well as the family cardiomyopathy with the digenic inheritance of two phenotypes (LVNC with DCM) and the unique case of peripartum evolution of the acquired LVNC syndrome, all these cases are reflect the current uncertainty regarding to the pathogenesis and significance of LVNC. The main question is whether LVNC is a distinct cardiomyopathy or a morphologic trait and a composite anatomical syndrome of congenital heart disease or other cardiomyopathies (DCM, HCM, ARVC) remains controversial. Achievement of professional consensus guidelines about unification of diagnostic criteria and risk-stratification of LVNC, improvement of visualization tools and expansion of genetic testing will help to significantly expand our knowledge and understanding of the pathogenesis, clinical significance and prognosis of LVNC for optimization of the treatment strategy.

Prevalence of left ventricle non-compaction criteria in adult patients with bicuspid aortic valve versus healthy control subjects

Objective

The aim of this study was to compare the prevalence of left ventricle non-compaction (LVNC) criteria (or hypertrabeculation) in a cohort of patients with bicuspid aortic valve (BAV) and healthy control subjects (CTL) without cardiovascular disease using cardiovascular MR (CMR).

Methods

79 patients with BAV and 85 CTL with tricuspid aortic valve and free of known cardiovascular disease underwent CMR to evaluate the presence of LVNC criteria. The left ventricle was assessed at end-systole and end-diastole, in the short-axis, two-chamber and four-chamber views and divided into the 16 standardised myocardial segments. LVNC was assessed using the non-compacted/compacted (NC/C) myocardium ratio and was considered to be present if at least one of the myocardial segments had a NC/C ratio superior to the cut-off values defined in previous studies: Jenni et al (>2.0 end-systole); Petersen et al (>2.3 end-diastole); or Fazio et al (>2.5 end-diastole).

Results

15 CTL (17.6%) vs 8 BAV (10.1%) fulfilled Jenni et al’s criterion; 69 CTL (81.2%) vs 49 BAV (62.0%) fulfilled Petersen et al’s criterion; and 66 CTL (77.6%) vs 43 BAV (54.4%) fulfilled Fazio et al’s criterion. Petersen et al and Fazio et al’s LVNC criteria were met more often by CTL (p=0.006 and p=0.002, respectively) than patients with BAV, whereas this difference was not statistically significant according to Jenni et al’s criterion (p=0.17). In multivariable analyses, after adjusting for age, sex, the presence of significant valve dysfunction (>mild stenosis or >mild regurgitation), indexed LV mass, indexed LV end-diastolic volume and LV ejection fraction, BAV was not associated with any of the three LVNC criteria.

Conclusion

Patients with BAV do not harbour more LVNC than the general population and there is no evidence that they are at higher risk for the development of LVNC cardiomyopathy.

Distribution of left ventricular trabeculation across age and gender in 140 healthy Caucasian subjects on MR imaging

PURPOSE

The purpose of this study was to quantify the distribution of trabeculated (T) and compact (C) left ventricular (LV) myocardium masses in a healthy Caucasian population against age, gender and LV parameters, and to provide normal values for T, C and T/C.

MATERIALS AND METHODS

One hundred and forty healthy subjects were prospectively recruited and underwent cardiac MRI at 1.5T with a stack of short-axis cine sequences covering the entire LV. End-diastolic volume (EDV), C and T masses were quantified using a semi-automatic method. Ejection fraction (EF) and T/C ratio were computed.

RESULTS

We included 70 men and 70 women with a mean age of 44±14 (SD) years (range: 20-69 years). The mean EF was 63.7±6.3 (SD) % (range: 50.7-82.0%), the mean EDV was 75.9±16.2 (SD) mL/m² (range: 36.4-112.2mL/m²), the mean C mass was 53.9±11.2 (SD) g/m² (range: 26.5-93.4g/m²) and the mean T mass was 4.9±2.4 (SD) g/m² (range: 1.1-11.4g/m²). The T/C ratio was 9.2±4.5% (range: 2.0-29.4%). Multivariate ANOVA test showed that the compact mass was influenced by EDV (P<0.0001), EF (P=0.001) and gender (P<0.0001), and the trabeculated mass depended on EDV (P<0.0001), gender (P=0.002) and age (P<0.0001), while the T/C ratio was only influenced by age (P=0.0003). Spearman test showed a correlation between EDV and C (r=0.60; P<0.0001),T (r=0.46; P<0.0001) and T/C ratio (r=0.26; P=0.0023).T and T/C ratio correlated with EF (r=-0.18, P=0.0373; r=-0.18, P=0.0321, respectively).

CONCLUSION

While the compact and trabeculated myocardium masses appear to relate separately to the cardiac function, age and gender, their ratio T/C appears to only decrease with age. Furthermore, we propose here normal values for T, C and T/C in a cohort of healthy Caucasians subjects.

Noncompaction cardiomyopathy and heterotaxy syndrome

Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by compact and trabecular layers of the left ventricular myocardium. This cardiomyopathy may occur with congenital heart disease (CHD). Single cases document co-occurrence of LVNC and heterotaxy, but no data exist regarding the prevalence of this association. This study sought to determine whether a non-random association of LVNC and heterotaxy exists by evaluating the prevalence of LVNC in patients with heterotaxy. In a retrospective review of the Indiana Network for Patient Care, we identified 172 patients with heterotaxy (69 male, 103 female). Echocardiography and cardiac magnetic resonance imaging results were independently reviewed by two cardiologists to ensure reproducibility of LVNC. A total of 13/172 (7.5%) patients met imaging criteria for LVNC. The CHD identified in this subgroup included atrioventricular septal defects [11], dextrocardia [10], systemic and pulmonary venous return abnormalities [7], and transposition of the great arteries [5]. From this subgroup, 61% (n = 8) of the patients developed arrhythmias; and 61% (n = 8) required medical management for chronic heart failure. This study indicates that LVNC has increased prevalence among patients with heterotaxy when compared to the general population (0.014-1.3%) suggesting possible common genetic mechanisms. Interestingly, mice with a loss of function of Scrib or Vangl2 genes showed abnormal compaction of the ventricles, anomalies in cardiac looping, and septation defects in previous studies. Recognition of the association between LVNC and heterotaxy is important for various reasons. First, the increased risk of arrhythmias demonstrated in our population. Secondly, theoretical risk of thromboembolic events remains in any LVNC population. Finally, many patients with heterotaxy undergo cardiac surgery (corrective and palliative) and when this is associated with LVNC, patients should be presumed to incur a higher peri-operative morbidity based on previous studies. Further research will continue to determine long-term and to corroborate genetic pathways.

Left Ventricular Noncompaction: A Distinct Genetic Cardiomyopathy?

Left ventricular noncompaction (LVNC) describes a ventricular wall anatomy characterized by prominent left ventricular (LV) trabeculae, a thin compacted layer, and deep intertrabecular recesses. Individual variability is extreme, and trabeculae represent a sort of individual "cardioprinting." By itself, the diagnosis of LVNC does not coincide with that of a "cardiomyopathy" because it can be observed in healthy subjects with normal LV size and function, and it can be acquired and is reversible. Rarely, LVNC is intrinsically part of a cardiomyopathy; the paradigmatic examples are infantile tafazzinopathies. When associated with LV dilation and dysfunction, hypertrophy, or congenital heart disease, the genetic cause may overlap. The prevalence of LVNC in healthy athletes, its possible reversibility, and increasing diagnosis in healthy subjects suggests cautious use of the term LVNC cardiomyopathy, which describes the morphology but not the functional profile of the cardiomyopathy.

Usefulness of speckle myocardial imaging modalities for differential diagnosis of left ventricular non-compaction of the myocardium

BACKGROUND/OBJECTIVES

Current diagnostic criteria for left ventricular non-compaction (LVNC) may result in over-diagnosis of the disease. We evaluate the role of speckle imaging in differential diagnosis of LVNC.

METHODS AND RESULTS

We included all patients who, between January 2012 and May 2015, fulfilled currently accepted criteria for LVNC (28 patients). A control group of 28 healthy individuals and a third group of 13 patients with dilated cardiomyopathy (DCM) were created. Speckle-tracking echocardiography was performed in all groups. Thirteen patients with LVNC had an ejection fraction (EF) <50% (33.5%, SD 10). When compared to controls, patients with LVNC and EF<50% had a larger LV, larger left atrial diameter (LA), reduced e', and reduced global longitudinal strain (GLS). All but one patient with LVNC and EF<50% showed an abnormal LV rotation. This abnormal pattern was observed in 4 LVNC patients (27%) with EF≥50% and in none of the controls. In patients with LVNC, EF ≥50%, and abnormal rotation, GLS was lower than in controls, (-17 (SD 3) vs -21 (SD 3)). Rigid body rotation (RBR) was also observed in 2 DCM patients, with significant differences in EF, GLS, LV diameters relative to the rest of the DCM group.

CONCLUSIONS

In patients who fulfil the morphologic criteria for LVNC, speckle myocardial imaging techniques could be useful in differentiating between healthy individuals (functionally normal LV) and patients with LVNC (with functional abnormalities in the myocardium in spite of a preserved EF).

Endocardial Remodeling in Heart Failure Patients with Impaired and Preserved Left Ventricular Systolic Function--A Magnetic Resonance Image Study

Left ventricular (LV) trabeculation has been studied in certain forms of cardiomyopathy. However, the changes of LV endocardial trabeculation during the remodeling process leading to heart failure (HF) are unclear. Seventy-four patients with systolic heart failure (SHF), 65 with heart failure with preserved ejection fraction (HFpEF) and 61 without HF were prospectively enrolled. All subjects received magnetic resonance imaging (MRI) study including cine, T1 and late gadolinium enhancement (LGE) images. Trabecular-papillary muscle (TPM) mass, fractal dimension (FD) and extracellular volume (ECV) were derived. The results showed that TPM mass index was higher in patients with SHF than that in patients with HFpEF and non-HF. The TPM mass-LV mass ratio (TPMm/LVM) was higher in SHF group than that in HFpEF and non-HF. FD was not different among groups. The presence of LGE was inversely associated with TPM mass index and TPMm/LVM while the ECV were positively associated with TPMm/LVM. The FD was positively associated with LV chamber size. In conclusion, TPM increases in patients with SHF and are probably related to myocardial cell hypertrophy and fibrotic repair during remodeling. The FD increases with the dilatation of LV chamber but remain unchanged with the deterioration of LV function.

Formation and Malformation of Cardiac Trabeculae: Biological Basis, Clinical Significance, and Special Yield of Magnetic Resonance Imaging in Assessment

Adult and pediatric cardiologists are familiar with variation in cardiac trabeculation. Abnormal trabeculation is a key feature of left ventricular noncompaction, but it is also common in congenital heart diseases and in cardiomyopathies (dilated and hypertrophied). Trabeculae might be a measurable phenotypic marker that will allow insights into how cardiomyopathy and congenital heart disease arise and develop. This will require the linking together of clinical and preclinical information (such as embryology and genetics), with new analysis methods for trabecular quantitation. In adult cardiology several promising quantitative methods have been developed for echocardiography, computed tomography, and cardiovascular magnetic resonance, and earlier cross-sectional caliper approaches have now been refined to permit more advanced assessment. Adaptation of these methods for use in developmental biology might inform on better ways to measure and track trabecular morphology in model organisms.