Systolic Myocardial Mechanics in Hypertrophic Cardiomyopathy: Novel Concepts and Implications for Clinical Status

Assessment of longitudinal systolic function using tissue motion annular displacement in cats with hypertrophic cardiomyopathy: a prospective case-control study

ObjectivesThe aim of this study was to investigate left ventricular (LV) longitudinal systolic function in cats with hypertrophic cardiomyopathy (HCM) and healthy control cats using tissue motion annular displacement (TMAD).MethodsThe study included 26 control cats and 21 HCM cats. All cats underwent assessment using two-dimensional echocardiography, M-mode echocardiography, pulsed-wave Doppler, tissue Doppler imaging techniques, longitudinal strain and TMAD.ResultsGlobal TMAD and percentage (%) global TMAD were not influenced by breed, sex, age or heart rate. Mean global TMAD and % global TMAD significantly decreased in the HCM group (2.86 ± 0.86 mm and 11.46% ± 3.37%, respectively) compared with the control group (3.95 ± 0.89 mm and 16.12% ± 2.94%, respectively) (P <0.001 for both), suggesting LV longitudinal systolic dysfunction in HCM cats. LV fractional shortening showed no difference between the control (52.76% ± 11.63%) and the HCM groups (59.80% ± 13.51%) (P = 0.061). Global TMAD and % global TMAD were significantly correlated with global longitudinal strain (P <0.001). The intraclass correlation coefficient of global TMAD and % global TMAD was considered moderate.Conclusions and relevanceGlobal TMAD and % global TMAD were significantly decreased in cats with HCM compared with the control group, and were sensitive and repeatable techniques for evaluating LV longitudinal systolic dysfunction in cats with HCM.

Post-carvedilol myocardial function in cats with obstructive hypertrophic cardiomyopathy

Introduction

Hypertrophic cardiomyopathy (HCM) is the most prevalent cardiac disease in cats, and one phenotype includes obstructive HCM with dynamic left ventricular outflow tract obstruction (DLVOTO). Myocardial function has been reported to be lower in cats with obstructive HCM than in non-obstructive HCM. Carvedilol, because of its pharmacological action, is expected to reduce the pressure gradient associated with DLVOTO, but no previous reports have studied its effects on myocardial function. This study aimed to evaluate myocardial function in cats with obstructive HCM with left ventricular outflow tract obstruction treated by carvedilol administration.

Methods

This retrospective observational study included 16 cats with obstructive HCM and subsequent treatment of DLVOTO with carvedilol. In addition to conventional echocardiography, strain and strain rates in the left ventricular longitudinal and circumferential directions were measured using layer-specific two-dimensional speckle tracking echocardiography. Each variable was then compared before and after carvedilol medication.

Results

Systolic anterior motion of the mitral valve disappeared in 14 cats and all cats showed resolved DLVOTO with maximal left ventricular outflow tract blood flow velocity of <2.5 m/s after carvedilol administration (P < 0.01). Circumferential strain in the epicardial layer and in the whole layer was significantly increased after carvedilol administration (P < 0.01, P = 0.04, respectively). In contrast, systolic longitudinal strain showed no significant difference between before and after carvedilol administration.

Conclusion

Treatment of obstructive HCM with carvedilol improved DLVOTO and myocardial function without a negative inotropic effect. Carvedilol may be effective in treating cats with obstructive HCM.

Functional myocardial assessment in cine cardiac computerized tomographic angiography using echocardiographic feature-tracking software in patients with and without significant coronary disease

Introduction

Cardiac computerized tomographic angiography (CCTA) is perceived as a non-invasive tool for assessment of coronary vessel anatomy. Feature tracking echocardiography has recently emerged as a tool for assessment of regional and global left ventricular function. We aimed to explore the applicability of echocardiographic strain on CCTA cine clips and assess whether global and regional strain parameters are associated with the extent of coronary stenosis.

Methods

CCTA studies of 61 consecutive patients were reconstructed to yield cine images in classic echocardiographic long and short views. Siemens Velocity Vector Imaging (VVI) software was applied to generate strain and displacement results. Volumetric and mechanics parameters were compared among patients with no or non-significant coronary artery disease (CAD) and patients with significant CAD. Finally, a comparison of the degree of coronary stenosis to regional segmental strain was performed.

Results

Myocardial mechanics parameters could be generated in 60 cases. Ejection fraction (EF) and left ventricular end diastolic volume (LVEDV) were within the normal range in both groups. VVI values were lower in the CAD group (VVI LVEF 59 ± 6 vs. 50 ± 11, p = 0.0002). Global longitudinal and global circumferential strain both were significantly lower in this group. Regional segmental strain was lower in segments affected by coronary stenosis in comparison to unaffected segments.

Conclusion

While CT segmentation derived LVEF did not differ among groups, patients with significant coronary stenosis had reduced longitudinal and circumferential contraction. This suggests that application of VVI to CCTA cine clips tracking may help to differentiate significant and non-significant coronary stenosis, adding functional value to anatomic findings in CCTA.

Clinical Implications of Left Ventricular Apex Mechanics in Patients With Apical Hypertrophic Cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) is a unique disease with pathologic hypertrophy mainly at the left ventricular (LV) apex. Although previous studies have indicated apical dysfunction in ApHCM, how apical mechanics change during disease progression has not been thoroughly examined. The aims of this study were to characterize the mechanics of the LV apex in patients with ApHCM at different disease stages and to explore the clinical significance of these alterations.

METHODS

One hundred four patients with ApHCM were divided into three subtypes on the basis of LV apical maximum wall thickness (AMWT) and extent of hypertrophy: relative type (isolated apical hypertrophy with AMWT < 15 mm), pure type (isolated apical hypertrophy with AMWT ≥ 15 mm), and mixed type (both apical and midventricular hypertrophy with AMWT ≥ 15 mm). Two-dimensional speckle-tracking echocardiography was used to analyze LV segmental strain, global strain, and twist. Comparisons of these parameters were performed among ApHCM subtypes and 30 healthy control subjects. Logistic regression and Cox proportional-hazards regression analyses were used to explore associations between myocardial mechanics and clinical indicators. A composite outcome of new-onset atrial fibrillation, heart failure hospitalization, myectomy, and all-cause mortality was assessed.

RESULTS

Even in relative ApHCM patients, apical longitudinal strain (LS), circumferential strain, and radial strain (RS) were significantly impaired compared with control subjects (LS: -14.6 ± 4.1% vs -20.0 ± 1.7% [P = .001]; circumferential strain: -19.6 ± 2.5% vs -25.6 ± 3.7% [P = .002]; RS: 26.6 ±7.4% vs 35.6 ± 11.1% [P = .026]), while apical rotation and LV twist remained unchanged. In patients with greater apical hypertrophy (mixed and pure patients), apical LS and RS were more abnormal. Moreover, apical rotation showed significant reductions compared with relative-type patients. After adjusting for clinical and myocardial mechanical parameters, apical rotation was independently associated with New York Heart Association functional class ≥ II (odds ratio, 0.81; 95% CI, 0.66-0.99; P = .036) and the composite outcome (hazard ratio, 0.82; 95% CI, 0.73-0.91; P = .001).

CONCLUSIONS

Relative ApHCM demonstrates apical dysfunction but sparing of apical rotation, which was abnormal in more extensive phenotypes. LV apex mechanics were closely related to clinical patterns, with apical rotation correlated with both New York Heart Association functional class ≥ II and clinical events.

A New Coding System for the Identification of Left Ventricular Rotation Patterns and Their Relevance to Myocardial Function

Rotational mechanics is a fundamental determinant of left ventricular ejection fraction (LVEF). The coding system currently employed in clinical practice does not distinguish between rotational patterns. We propose an alternative coding system that makes possible to identify the rotational pattern of the LV and relate it to myocardial function. Echocardiographic images were used to generate speckle tracking-derived transmural global longitudinal strain (tGLS) and rotational parameters. The existence of twist (basal and apical rotations in opposite directions) is expressed as a rotational gradient with a positive value that is the sum of the basal and apical rotation angles. Conversely, when there is rigid rotation (basal and apical rotations in the same direction) the resulting gradient is assigned a negative value that is the subtraction between the two rotation angles. The rotational patterns were evaluated in 87 healthy subjects and 248 patients with LV hypertrophy (LVH) and contrasted with their myocardial function. Our approach allowed us to distinguish between the different rotational patterns. Twist pattern was present in healthy controls and 104 patients with LVH and normal myocardial function (tGLS ≥ 17%, both). Among 144 patients with LVH and myocardial dysfunction (tGLS < 17%), twist was detected in 83.3% and rigid rotation in 16.7%. LVEF was < 50% in 34.7%, and all patients with rigid rotation had a LVEF < 50%. The gradient rotational values showed a close relationship with LVEF (r = 0.73; p < 0.001). The proposed coding system allows us to identify the rotational patterns of the LV and to relate their values with LVEF.

Multimodality Imaging in Patients with Hypertrophic Cardiomyopathy and Atrial Fibrillation

Ventricular hypertrophy is associated with diastolic dysfunction, resulting in increased left atrial (LA) pressure, enlargement, fibrosis, and decreased LA function. Hypertrophic cardiomyopathy (HCM) is characterized by myocyte disarray, myocardial fibrosis, and hypertrophy. Notably, a thickened and noncompliant LV results in the impairment of diastolic function. These conditions promote LA remodeling and enlargement, which contribute to developing and maintaining atrial fibrillation (AF). AF is an atrial arrhythmia that occurs frequently in HCM, and evaluating the morphology and physiology of the atrium and ventricle is important for treatment and prognosis determination in HCM patients with AF. In addition, it provides a clue that can predict the possibility of new AF, even in patients not previously diagnosed with AF. Cardiac magnetic resonance (CMR), which can overcome the limitations of transthoracic echocardiography (TTE), has been widely used traditionally and even enables tissue characterization; moreover, it has emerged as an essential imaging modality for patients with HCM. Here, we review the role of multimodal imaging in patients with HCM and AF.

Exaggerated myocardial torsion may contribute to dynamic left ventricular outflow tract obstruction in hypertrophic cardiomyopathy

Aims

Dynamic left ventricular (LV) outflow tract obstruction (LVOTO) is associated with symptoms and increased risk of developing heart failure in hypertrophic cardiomyopathy (HCM). The association of LVOTO and LV twist mechanics has not been well studied in HCM. The aim of the study was to compare the pattern of LV twist in patients with HCM associated with asymmetrical septal hypertrophy with and without LVOTO.

Methods and results

Echocardiography (including speckle tracking) was performed in 212 patients with HCM, divided according to the absence (n = 130) or presence (n = 82) of LVOTO (defined as peak pressure gradient ≥30 mmHg either at rest and/or with Valsalva manoeuvre). Patients with LVOTO were older, had smaller LV dimensions, a higher LV ejection fraction (LVEF), a longer anterior mitral valve leaflet length, and a higher early transmitral pulsed wave to septal tissue Doppler velocity ratio (E/E'). A univariate analysis showed that peak twist was significantly higher in patients with LVOTO compared with patients without LVOTO (19.7 ± 7.3 vs. 15.7 ± 6.0, P = 0.00015). Peak twist was similarly enhanced in patients with LVOTO, manifesting only during Valsalva (19.2 ± 5.6, P = 0.007) and patients with resting LVOTO (19.9 ± 8.0, P = 0.00004) compared with patients without LVOTO (15.7 ± 6.0). A stepwise forward logistic regression analysis showed that LVEF, LV end-systolic dimension indexed to body surface area, anterior mitral valve leaflet length, E/E', and peak twist were all independently associated with LVOTO.

Conclusion

This study demonstrates that increased peak LV twist is independently associated with LVOTO in patients with HCM. Peak twist was similarly exaggerated in patients with only latent LVOTO, suggesting that it may play a contributory role to LVOTO in HCM.

Comparative study of myocardial function in cases of feline hypertrophic cardiomyopathy with and without dynamic left-ventricular outflow-tract obstruction

In recent years, hypertrophic cardiomyopathy (HCM) in cats has become much more common in clinical practice due to improvements in diagnostic techniques and equipment performance. One phenotype is obstructive HCM with left ventricular (LV) outflow tract obstruction (DLVOTO). It has been reported that the presence or absence of DLVOTO does not affect long-term prognosis in cats with HCM. In this study, we evaluated and compared myocardial function in HCM-affected cats with and without DLVOTO using the two-dimensional speckle-tracking echocardiography. LV longitudinal strain of the endocardial, epicardial, and whole layer and LV circumferential strain of the epicardium were significantly decreased in all HCM-affected cats compared to healthy cats. However, these values were not significantly different between those with and without DLVOTO. In contrast, the endocardial and whole layers of LV circumferential strain were only significantly decreased in HCM-affected cats with DLVOTO compared to healthy cats. This could be attributed to the fact that the LV pressure load associated with DLVOTO affected the endocardial myocardium more in the LV endocardial layer, and that lower values of LV endocardial strain lowered the values of LV strain in the whole layer. In conclusion, our results suggest that LV myocardial function may have been more compromised in the HCM-affected cats with DLVOTO.

Multimodality Imaging in Sarcomeric Hypertrophic Cardiomyopathy: Get It Right…on Time

Hypertrophic cardiomyopathy (HCM) follows highly variable paradigms and disease-specific patterns of progression towards heart failure, arrhythmias and sudden cardiac death. Therefore, a generalized standard approach, shared with other cardiomyopathies, can be misleading in this setting. A multimodality imaging approach facilitates differential diagnosis of phenocopies and improves clinical and therapeutic management of the disease. However, only a profound knowledge of the progression patterns, including clinical features and imaging data, enables an appropriate use of all these resources in clinical practice. Combinations of various imaging tools and novel techniques of artificial intelligence have a potentially relevant role in diagnosis, clinical management and definition of prognosis. Nonetheless, several barriers persist such as unclear appropriate timing of imaging or universal standardization of measures and normal reference limits. This review provides an overview of the current knowledge on multimodality imaging and potentialities of novel tools, including artificial intelligence, in the management of patients with sarcomeric HCM, highlighting the importance of specific "red alerts" to understand the phenotype-genotype linkage.

Prognostic value of global longitudinal strain in hypertrophic cardiomyopathy: A systematic review and meta-analysis

BACKGROUND

As previously reported, impairment of left ventricular global longitudinal strain (LVGLS) is associated with myocardial fibrosis, arrhythmias, and heart failure in hypertrophic cardiomyopathy (HCM) patients.

HYPOTHESIS

This study aimed to estimate the association between LVGLS measured by echocardiography and major adverse cardiovascular events (MACE) in patients with HCM.

METHODS

Pubmed, Embase, Scopus, and Cochrane Library databases were systematically searched for evaluating the difference of LVGLS between MACE and non-MACE and the relevance of LVGLS and MACE in HCM patients, mean difference (MD), and pooled hazard ratios (HR) with 95% confidence interval (CI) were calculated. Publication bias was detected by funnel plots and Egger's test, and trim-and-fill analysis was employed when publication bias existed.

RESULTS

A total of 13 studies reporting 2441 HCM patients were included in this meta-analysis. Absolute value of LVGLS was lower in the group of HCM with MACE (MD = 2.74, 95% CI: 2.50-2.99, p < .001; I²  = 0, p = .48). In the pooled unadjusted model, LVGLS was related to MACE (HR = 1.14, 95% CI: 1.06-1.22, p < .05, I²  = 58.4%, p < .01) and there is a mild heterogeneity, and sensitivity analysis showed stable results. In the pooled adjusted model, LVGLS was related to MACE (HR = 1.12, 95% CI: 1.08-1.16, p < .05; I²  = 0%, p = .442). Egger's tests showed publication bias, and trim-and-fill analysis was applied, with final results similar to the previous and still statistically significant.

CONCLUSION

The meta-analysis suggested that impaired LVGLS was associated with poor prognosis in HCM patients.

Impaired Left Ventricular Contractile Reserve in Patients With Hypertrophic Cardiomyopathy and Abnormal Blood Pressure Response: A Stress Echocardiographic Study

BACKGROUND

Abnormal blood pressure response (ABPR) has been reported to be a risk factor for sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). We aimed to elucidate the relationship between ABPR during exercise stress echocardiography (ESE) and impaired left ventricular (LV) contractile reserve based on two-dimensional strain in patients with HCM.

METHODS

Patients with HCM underwent ESE with treadmill exercise. Patients whose blood pressure elevation at maximum workload was lower than 20 mmHg from baseline were classified as having ABPR. Echocardiographic parameters were compared between patients with and without ABPR.  Results: Of 26 patients with HCM, nine patients were diagnosed with ABPR. Significant LV outflow tract obstruction (>50 mmHg) was provoked only in one patient with ABPR (baseline to the conclusion of the exercise, 15.2 mmHg to 63.0 mmHg). Change in cardiac output (CO) and the ratio of early diastolic velocity to early annular velocity (E/e') from baseline to just after the conclusion of exercise did not differ between patients with and without ABPR (CO, 102±40% vs. 122±45%, P = 0.19; E/e', 4±22% vs. 2±20%, P = 0.86). Change in systemic vascular resistance change was not significant (patients with vs. without ABPR, -52±10% vs. -46±13%, P = 0.24). Percent change in LV global longitudinal strain was lower in patients with ABPR than patients without ABPR (12±17% vs. 27±15%, P = 0.02).

CONCLUSION

In conclusion, impaired LV contractile reserve during exercise might contribute to ABPR in patients with HCM.

The role of conventional echocardiographic parameters on detecting subclinical anthracycline therapy related cardiac dysfunction—The SATRACD study

Background

Subclinical anthracycline therapy related cardiac dysfunction (ATRCD) can be detected with speckle tracking echocardiographic image (STE), which is not widely available in Uganda. We aimed to investigate the role of the two conventional echocardiographic parameters [mitral annular plane systolic excursion (MAPSE) and mitral annular peak systolic tissue Doppler velocity (S’)] on diagnosing subclinical ATRCD.

Method and results

207 cancer patients who underwent anthracycline based chemotherapy were recruited at baseline and followed up until 6 months after ending anthracycline therapy. Comprehensive echocardiographic data were collected at each visit. Global longitudinal strain (GLS) by STE was used as the gold standard diagnostic test to define the case of subclinical ATRCD. Data of the 200 patients who had no evidence of clinical ATRCD were analyzed. One hundred and seventy-two (86.0%) were female, with a median age of 42 years and 47 (23.5%) patients were diagnosed with subclinical ATRCD at the end of anthracycline therapy by GLS criteria. The area under the curve (AUC), cutoff point, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of reduction of MAPSE (ΔMAPSE) were 0.6736 (95% CI: 0.5885, 0.7587), ≥ 2 mm, 74.5% (95% CI: 59.7%, 86.1%), 54.9% (95% CI: 46.7%, 63.0%), 33.7% (95% CI: 24.7%, 43.6%), and 87.5% (95% CI: 79.2%, 93.4%). The AUC, cutoff point, sensitivity, specificity, PPV, and NPV of reduction of S’ (ΔS’) were 0.6018 (95% CI: 0.5084, 0.6953), ≥ 0.5 cm/s, 61.7% (95% CI: 46.4%, 75.5%), 52.7% (95% CI: 44.4%, 60.9%), 29.0% (95% CI: 20.4%, 38.9%), and 76.1% (95% CI: 72.4%, 88.6%). When ΔMAPSE and ΔS’ are used as parallel test, the net sensitivity and specificity is 89.4% and 28.8%, respectively, the net PPV and NPV is 27.8% and 90.0%, respectively.

Conclusion

The ΔMAPSE and ΔS’ showed fairly good accuracy, sensitivity and NPV to detect subclinical ATRCD in Ugandan cancer patients. These conventional echocardiographic parameters may serve as screening tools for detecting subclinical ATRCD in resource limited settings.

Obstructive and Nonobstructive Hypertrophic Cardiomyopathy: Differences in Global and Segmental Myocardial Strain by Cardiac Magnetic Resonance Feature Tracking

PURPOSE

To evaluate any significant differences in myocardial strain between hypertrophic obstructive cardiomyopathy (HOCM) and nonobstructive ones (HNCM), as assessed by cardiac magnetic resonance feature tracking (CMR-FT).

MATERIALS AND METHODS

A total of 17 patients (mean age: 54±14 y) with echocardiographic diagnosis of HOCM (left ventricular outflow tract obstruction peak gradient ≥30 mm Hg), 19 patients (mean age: 49±16 y) with HNCM (peak gradient <30 mm Hg), and 18 age-matched and gender-matched healthy controls (mean age: 42±14 y). All patients underwent cardiac MRI with SSFP-cine to assess left ventricular global and segmental strain analysis by CMR-FT. Late gadolinium enhancement (LGE) sequences were used for semiautomatic quantification of LGE volume, mass, and percentage.

RESULTS

The magnitude of global radial, circumferential, and longitudinal strain as well as strain rate were significantly lower in all patients in comparison to controls (P<0.001), except for radial and circumferential strain between HOCM and controls (P=0.270; P=0.154). The latter strain parameters were significantly higher in HOCM than HNCM (radial strain: 31.67±7.55 vs. 21.26±7.10, P<0.001; circumferential strain: -17.94±2.78 vs. -13.46±3.42, P<0.001). Radial and circumferential strain and circumferential diastolic strain rate were higher in mid-anterior (P<0.001), mid-anteroseptal (P<0.001), and all apical segments (P<0.005) between the 2 groups of patients. Moreover, longitudinal strain was higher only in apical segments in HOCM (P<0.02).

CONCLUSIONS

HOCM patients showed higher left ventricular apical, mid-anterior, and mid-anteroseptal strain parameters compared with HNCM. These differences were independent of corresponding segmental thickness and LGE amount.

3D speckle tracking echocardiographic strain pattern in Hypertrophic Cardiomyopathy and its relation with Sudden Cardiac Death risk markers

CONTEXT

Sudden cardiac death (SCD) predictability for assessing the need for primary insertion of Implantable Cardioverter Defibrillator (ICD) in patients with Hypertrophic cardiomyopathy (HCM) is difficult though there are several conventional risk markers. The role of deformation indices in predicting SCD in HCM is less addressed.

OBJECTIVES

To analyse the 3D speckle tracking echocardiographic strain parameters of HCM patients and its relation with SCD risk markers.

DESIGN AND STUDY METHODOLOGY

It was a cross-sectional observation study done over a period of one year with a follow up period of one year. Fifty HCM patients were included after screening eighty-two patients. Their global LV strain parameters, Global Longitudinal Strain (GLS), Global Circumferential Strain (GCS), Global Radial Strain (GRS) and Global area strain (GAS) were analysed with respect to their age and gender-matched controls. The various strain parameters were correlated with the conventional SCD risk markers and the ESC SCD risk score among these HCM patients.

RESULTS

All the global strain parameters were significantly low in HCM patients compared to their controls {GLS -7.30 ± 3.424 vs -18.78 ± 2.342, p < 001; GCS -11.26 ± 2.754 vs -25.08 ± 3.542, p < 001; GRS 20.56 ± 8.929 vs 39.70 ± 7.546, p < 001}. On subgroup analysis of HCM patients with LV thickness >30 mm, abnormal exercise test, family history of SCD, LVOT gradients >30mmHgand more than one SCD risk marker had significantly low values for all global deformation parameters, when compared with their control HCM cohort. The ESC risk score also had significant inverse correlation with all deformation parameters (GLS 0.496, p < 0.001; GCS 0.491, p < 0.001; GRS -0.529, p < 0.001; GAS 0.519, p < 0.001). On follow up, only one event was recorded in this cohort.

CONCLUSION

There exists a possible linear correlation between conventional SCD risk markers and 3D deformation parameters, which may be utilized for risk stratification and SCD predictability in HCM patients after confirmation with further large prospective studies.

RETRACTED: Diagnosis of Early Left Ventricular Systolic Dysfunction by Layer-Specific Strain Echocardiography in Diabetic Rabbits

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor. The authors have copied figures and text verbatim from another manuscript published by the first author and others in Med Ultrason, 18 (2016) 339–344; doi:10.11152/mu.2013.2066.183.qia. We apologize to readers of the journal for this incident.

The predictive value of left ventricular and left atrial mechanics for atrial fibrillation and heart failure in hypertrophic cardiomyopathy: a prospective cohort study

Atrial fibrillation (AF) and heart failure (HF) represent clinical turning points, altering the natural history of HCM and influencing long-term outcome of the disease. The aim of this study was to evaluate the ability of left ventricular (LV) and left atrial (LA) myocardial deformation parameters to predict new-onset AF and HF outcomes in patients with HCM. This was a prospective study that included HCM patients without severe valvular heart disease, prior myocardial infarction or history of AF. The study sample consisted of 250 patients (mean age 50.8 ± 15.8, 67.2% male). Two-dimensional (2D) speckle tracking deformation parameters including global longitudinal strain (GLS), radial strain, circumferential strain, LA reservoir strain (LAε_res), LA conduit strain (LAε_con) and LA booster strain(LAε_boost) were examined. During a mean follow-up of 2.5 ± 1.2 years, 44 patients developed new-onset AF. All the LV and LA deformation parameters were significant univariate predictors of AF. GLS and LAε_res had the highest C statistic among the LV and LA functional indices. In multivariable analysis, only LAε_res remained an independent predictor of the arrhythmia (HR 0.91, 95% CI 0.85-0.98, p: 0.008). Similarly, GLS and LAε_res had the highest predictive value among the 2D speckle tracking parameters for HF outcomes. LAε_res remained an independent predictor after adjusting for significant covariates. GLS and LAε_res demonstrated high predictive value for the development of AF and HF in HCM. LAε_res was the only independent predictor of both outcomes.Clinical trial registration: ClinicalTrials.gov identifier: NCT04112511.

Association between genetic variants in the HIF1A-VEGF pathway and left ventricular regional myocardial deformation in patients with hypertrophic cardiomyopathy

BACKGROUND

Information on genetic etiology of pediatric hypertrophic cardiomyopathy (HCM) rarely aids in risk stratification and prediction of disease onset. Little data exist on the association between genetic modifiers and phenotypic expression of myocardial performance, hampering an individual precision medicine approach.

METHODS

Single-nucleotide polymorphism genotyping for six previously established disease risk alleles in the hypoxia-inducible factor-1α-vascular endothelial growth factor pathway was performed in a pediatric cohort with HCM. Findings were correlated with echocardiographic parameters of systolic and diastolic myocardial deformation measured by two-dimensional (2-D) speckle-tracking strain.

RESULTS

Twenty-five children (6.1 ± 4.5 years; 69% male) with phenotypic and genotypic (60%) HCM were included. Out of six risk alleles tested, one, VEGF1 963GG, showed an association with reduced regional systolic and diastolic left ventricular (LV) myocardial deformation. Moreover, LV average and segmental systolic and diastolic strain and strain rate were significantly reduced, as assessed by the standardized difference, in patients harboring the risk allele.

CONCLUSIONS

This is the first study to identify an association between a risk allele in the VEGF pathway and regional LV myocardial function, with the VEGF1 963GG allele associated with reduced LV systolic and diastolic myocardial performance. While studies are needed to link this information to adverse clinical outcomes, this knowledge may help in risk stratification and patient management in HCM.

IMPACT

Risk allele in the VEGF gene impacts on LV myocardial deformation phenotype in children with HCM. LV 2-D strain is significantly reduced in patients with risk allele compared to non-risk allele patients within HCM patient groups. Describes that deficiencies in LV myocardial performance in children with HCM are associated with a previously identified risk allele in the angiogenic transcription factor VEGF. First study to identify an association between a risk allele in the VEGF pathway and regional LV myocardial deformation measured by 2-D strain in children with HCM.

Segmental longitudinal strain as the most accurate predictor of the patchy pattern late gadolinium enhancement in hypertrophic cardiomyopathy

BACKGROUND

The prognostic value of myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM) has been well-established. Although cardiac magnetic resonance (CMR) is the method of choice in its revealing as the presence of late gadolinium enhancement (LGE), this technique still has limited availability in daily clinical practice. Two-dimensional speckle tracking echocardiography (2D STE) seems to be helpful in verification which HCM patient has the highest probability of LGE presence and hence needs to be qualified to CMR. While the majority of HCM patients have a patchy pattern of myocardial fibrosis, the aim of this study was to evaluate whether segmental rather than global longitudinal strain is more accurate in the identification of the presence of LGE.

METHODS

Forty-six HCM patients had transthoracic echocardiography and CMR imaging performed. Each patient had global longitudinal strain and rotation parameters calculated, as well as segmental analyses for wall thickness, longitudinal strain, and LGE presence based on 736 segments of the left ventricle (LV). The presence of LGE in CMR was confirmed on a per-segment basis, which was similar to LV segments in the echocardiographic examination. All patients were divided into two groups according to the CMR result: LGE (+) and LGE (-).

RESULTS

Receiver-operating characteristic analyses identified peak global longitudinal strain and peak twisting velocity with the cut-off values -14.4% and 116°/s respectively as the accurate predictors of LGE presence in CMR, whereas segmental longitudinal strain of -12.5% cut-off value had the highest area under the curve value (87.4%, confidence interval 84.5-90.3%), with 93.7% sensitivity, 86.5% negative predictive value, and 55% specificity.

CONCLUSIONS

Segmental longitudinal strain with the cut-off value of -12.5% has the highest discriminatory power for LGE presence and seems to be more adequate than global speckle tracking parameters in identification of HCM patients with strong indications for CMR for more accurate risk stratification.

Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy: The Utility of Myocardial Strain Based on Cardiac MR Tissue Tracking

BACKGROUND

Myocardial strain for assessment of hypertrophic cardiomyopathy (HCM) is of importance and may play a role in identifying obstruction in HCM patients.

PURPOSE

To evaluate the utility of myocardial strain for detecting left ventricular (LV) outflow tract (LVOT) obstruction in HCM patients based on magnetic resonance tissue tracking.

STUDY TYPE

Retrospective.

POPULATION

In all, 44 adult HCM patients with LVOT obstruction and 108 adult HCM patients without LVOT obstruction.

FIELD STRENGTH/SEQUENCE

1.5 T; Steady-state free-precession cine sequence; phase-sensitive inversion-prepared segmented gradient echo sequence for late gadolinium enhancement (LGE) imaging.

ASSESSMENT

Strain parameters including the local and global levels of LV myocardium and the subtraction (Sub) of myocardial strain variables between interventricular septal segments (IVSS) and noninterventricular septal segments (NIVSS) were measured for differentiating HCM with obstruction from nonobstruction. Average and maximum LV wall thickness (Average and Maximum LVWT) were also analyzed.

STATISTICAL TESTS

Univariate and multivariate logistic regression analysis, area under the receiver operating characteristic (ROC) curve (AUC), intraclass correlation coefficient.

RESULTS

In multivariate analysis, Average LVWT, Maximum LVWT, and the subtraction of radial peak strain (Sub Radial PS) between NIVSS and IVSS were independently associated with LVOT obstruction. The AUCs were 0.731, 0.840, and 0.890 for Average LVWT, Maximum LVWT, and Sub Radial PS, respectively. Sub Radial PS (cutoff value: 8.1%) demonstrated the highest sensitivity of 75.0% and a high specificity of 87.9% for identifying LVOT; Maximum LVWT (cutoff value: 22.9 mm) showed good sensitivity (72.7%) and specificity (83.3%). Combining Maximum LVWT >22.9 mm and Sub Radial PS > 8.1% achieved a better diagnostic performance (specificity 95.4%, sensitivity 70.5%).

DATA CONCLUSION

Combining Maximum LVWT >22.9 mm and Sub Radial PS >8.1% holds promise for objectively evaluating LVOT obstruction in HCM patients with very high specificity and acceptable sensitivity.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Relationships of global longitudinal strain with s`, long-axis systolic excursion, left ventricular length and heart rate

Background

Longitudinal left ventricular (LV) contraction can be impaired in the presence of a normal LV ejection fraction (LVEF), and abnormalities have been reported in global longitudinal strain (GLS), long-axis systolic excursion (SExc), and the peak systolic velocity (s`) of mitral annular motion using tissue Doppler imaging (TDI). However, the relationships of GLS with s` and SExc have not been systematically evaluated in subjects with a normal LVEF, and whether these relationships might be affected by variations in LV end-diastolic length (LVEDL) and heart rate is unknown.

Methods

We investigated the univariate and multivariate correlations of GLS with TDI measurements of s` and SExc (both using averages of the septal and lateral walls), LVEDL and heart rate in subjects with a normal LVEF (>50%) but a low peak early diastolic mitral annular velocity (septal e`≤ 7.0 cm/s and lateral e`≤ 9 cm/s), and thus an increased risk of a future cardiac event.

Results

84 subjects (age 66±8 years, 29 males) with a LVEF of 62±6% and GLS of -17.5±2.3% were studied. On univariate analysis the absolute value of GLS was positively correlated with s`(r = 0.28, p<0.01) and SExc (r = 0.50, p<0.001) and inversely correlated with heart rate (r = -0.36, p = 0.001), but was not correlated with LVEDL (r = -0.15). In multivariate models, SExc explained more of the variance in GLS than s`, and absolute GLS was not only positively correlated with SExc, but also inversely correlated with LVEDL. Heart rate was an independent inverse correlate of GLS in conjunction with LVEDL and either s` or SExc, but made a larger contribution in models which included s`. Interobserver correlations were close for s` and SExc (r = 0.89–0.93), but only moderate for GLS (r = 0.71).

Conclusion

In subjects with a normal LVEF but reduced e`, the absolute value of GLS is more closely related to SExc than s`, and is also independently and inversely related to LVEDL and heart rate. Measurement of SExc may provide a useful additional or alternative technique to GLS for the assessment of LV long-axis function.

Assessment of left ventricular systolic function in hypertrophic cardiomyopathy patients with myocardial injury: a study based on layer-specific speckle tracking echocardiaography

We conducted this study to investigate left ventricle (LV) systolic function in endocardial, mid-myocardial, and epicardial layers by two-dimensional (2D) speckle tracking echocardiography (STE) in hypertrophic cardiomyopathy (HCM) patients with myocardial injury indexed by elevated serum cardiac troponin I (cTnI). Twenty-nine HCM patients with myocardial injury, thirty-five HCM patients without myocardial injury, and ninty-one healthy controls were enrolled in this study. Serum cTnI > 0.026 ng/mL was defined as myocardial injury. LV longitudinal and circumferential strain (LS and CS) were assessed in endocardial, mid-myocardial and epicardial layers. Layer-specific LS and CS differed significantly (all P < 0.001) among all three groups in all three layers, in a descending order from healthy controls to HCM patients without myocardial injury to HCM patients with myocardial injury. Layer-specific LS and CS were decreased the most in HCM patients with myocardial injury indexed by elevated seum cTnI (all P < 0.05). In HCM patients with myocardial injury, layer-specific LS and CS were significantly lower in the segments with greater hypertrophy (segmental thickness ≥ 15 mm) (all P < 0.001) except for endocardial CS (P > 0.05). Layer-specific evaluation of LV strain may improve understanding of impaired LV systolic function in HCM patients with myocardial injury, thus preventing further damage.

Usefulness of Myocardial Strain and Twist for Early Detection of Myocardial Dysfunction in Patients With Autoimmune Diseases

Cardiac involvement in autoimmune diseases (AD) is common but underdiagnosed due to a lack of sensitive imaging methods. We aim to evaluate the characteristics of left ventricular (LV) systolic dysfunction in patients with AD using deformational parameters from 2-dimensional speckle-tracking echocardiography (STE). We retrospectively enrolled 86 AD patients and 71 healthy controls. All subjects underwent transthoracic echocardiography and STE to analyze LV strain and twist. A twist-radial displacement loop was constructed to investigate the relation between LV contractility and dimension. In AD patients, 68 had preserved LV ejection fraction (EF ≥ 50%), and 18 had reduced LVEF (EF < 50%). The patients with preserved LVEF exhibited significantly lower values of global longitudinal, circumferential, and radial strain than controls (-19.11 ± 4.18 vs -21.49 ± 2.53%, -25.17 ± 5.04% vs -27.37 ± 2.87%, 17.68 ± 5.69% vs 21.17 ± 6.44%, respectively; all p <0.01) and a marked attenuation in peak twist (14.24 ± 5.57 vs 18.10 ± 5.97, p <0.01) attributed to impaired apical rotation (9.03 ± 5.17 vs 12.79 ± 5.99, p <0.01). AD patients were more likely to present with abnormal loop types with flat ascending slope and delayed peak twist time. In conclusion, abnormal strain and twist precede deterioration in LVEF, suggesting early myocardial involvement in AD. STE can be used as a good alternative for early detection of myocardial dysfunction in AD patients.

Echocardiographic tissue imaging evaluation of myocardial characteristics and function in cardiomyopathies

Current echocardiography techniques have allowed more precise assessment of cardiac structure and function of the several types of cardiomyopathies. Parameters derived from echocardiographic tissue imaging (ETI)-tissue Doppler, strain, strain rate, and others-are extensively used to provide a framework in the evaluation and management of cardiomyopathies. Generally, myocardial function assessed by ETI is depressed in all types of cardiomyopathies, non-ischemic dilated cardiomyopathy (DCM) in particular. In hypertrophic cardiomyopathy (HCM), ETI is useful to identify subclinical disease in family members of HCM, to differentiate HCM from other conditions causing cardiac hypertrophy and to predict cardiac events. ETI also for HCM allows addressing the mechanism behind left ventricular outflow tract obstruction and its improvement after therapeutic options. ETI provides cardiac amyloidosis with unique and specific findings such as "apical sparing." Nevertheless, ETI does not seem to provide as much information amenable to histological findings as recently emerging techniques of cardiac magnetic resonance imaging. This review introduces usefulness of ETI and some other ultrasound techniques for detecting clinical and subclinical characteristics of cardiomyopathies, focusing on DCM, HCM, and cardiac amyloidosis.

Cardiac Function in Infants Born to Mothers With Gestational Diabetes - Estimation of Early Diastolic Intraventricular Pressure Differences

Background: This study compared the myocardial performance of infants born to mothers with gestational diabetes mellitus (IGDM) and without GDM (controls) under the new GDM definitions.

Methods and Results: The subjects consisted of 36 IGDM and 39 control infants. GDM diagnosis was based on oral glucose tolerance test during pregnancy or the presence of diabetes prior to the current pregnancy. Between-group infant cardiac function was determined and compared using 2-D speckle tracking analysis, intraventricular pressure difference (IVPD) and IVP gradient (IVPG), using color M-mode Doppler imaging. IVPD and IVPG were higher in IGDM than in the controls, particularly the mid–apical IVPG. The global circumferential strain (GCS) and endocardial GCS were higher in IGDM than in controls. Increased maternal glycated hemoglobin was correlated with reduced transmural and epicardial GCS in the IGDM. Maternal maximum fasting blood sugar had a mild, positive correlation with IVPD and IVPG.

Conclusions: Ventricular sucking force, measured as the IVPD, IVPG, and endocardial GCS, were higher in IGDM than in the controls. A hyperglycemic environment during pregnancy leads to impaired cardiac performance in IGDM, compared with control infants. IGDM might have favorable systolic and diastolic cardiac performance due to cardiac metabolic adaptations occurring before poor glucose control causes impaired cardiac performance.

Cardiovascular magnetic resonance feature tracking strain analysis for discrimination between hypertensive heart disease and hypertrophic cardiomyopathy

Background

Hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM) are both associated with an increased left ventricular (LV) wall thickness. Whilst LV ejection fraction is frequently normal in both, LV strain assessment could differentiate between the diseases. We sought to establish if cardiovascular magnetic resonance myocardial feature tracking (CMR-FT), an emerging method allowing accurate assessment of myocardial deformation, differentiates between both diseases. Additionally, CMR assessment of fibrosis and LV hypertrophy allowed association analyses and comparison of diagnostic capacities.

Methods

Two-hundred twenty-four consecutive subjects (53 HHD, 107 HCM, and 64 controls) underwent 1.5T CMR including native myocardial T₁ mapping and late gadolinium enhancement (LGE). Global longitudinal strain (GLS) was assessed by CMR-FT (CVi42, Circle Cardiovascular Imaging Inc.).

Results

GLS was significantly higher in HCM patients (-14.7±3.8 vs. -16.5±3.3% [HHD], P = 0.004; or vs. -17.2±2.0% [controls], P<0.001). GLS was associated with LV mass index (HHD, R = 0.419, P = 0.002; HCM, R = 0.429, P<0.001), and LV ejection fraction (HHD, R = -0.493, P = 0.002; HCM, R = -0.329, P<0.001). In HCM patients, GLS was also associated with global native T₁ (R = 0.282, P = 0.003), and LGE volume (ρ = 0.380, P<0.001). Discrimination between HHD and HCM by GLS (c = 0.639, 95% confidence interval [CI] 0.550–0.729) was similar to LV mass index (c = 0.643, 95% CI 0.556–0.731), global myocardial native T₁ (c = 0.718, 95% CI 0.638–0.799), and LGE volume (c = 0.680, 95% CI 0.585–0.775).

Conclusion

CMR-FT GLS differentiates between HHD and HCM. In HCM patients GLS is associated with myocardial fibrosis. The discriminatory capacity of CMR-FT GLS is similar to LV hypertrophy and fibrosis imaging markers.

Exploring the Continuum of Hypertrophic Cardiomyopathy-From DNA to Clinical Expression

The concepts underlying hypertrophic cardiomyopathy (HCM) pathogenesis have evolved greatly over the last 60 years since the pioneering work of the British pathologist Donald Teare, presenting the autopsy findings of "asymmetric hypertrophy of the heart in young adults". Advances in human genome analysis and cardiac imaging techniques have enriched our understanding of the complex architecture of the malady and shaped the way we perceive the illness continuum. Presently, HCM is acknowledged as "a disease of the sarcomere", where the relationship between genotype and phenotype is not straightforward but subject to various genetic and nongenetic influences. The focus of this review is to discuss key aspects related to molecular mechanisms and imaging aspects that have prompted genotype-phenotype correlations, which will hopefully empower patient-tailored health interventions.

Cardiovascular Magnetic Resonance Provides Evidence of Abnormal Myocardial Strain and Primary Cardiomyopathy in Marfan syndrome

OBJECTIVE

Marfan syndrome is an autosomal-dominant genetic disorder caused by mutations in the fibrillin-1 gene. The condition is a connective tissue disease that frequently involves the cardiovascular system. The existence of a primary cardiomyopathy in Marfan syndrome, however, is controversial. The aims of this study were to investigate the prevalence of left ventricular dysfunction with both transthoracic echocardiography and cardiovascular magnetic resonance (CMR) in a cohort of Marfan syndrome patients and to investigate patterns of myocardial strain across the cohort.

METHODS

We used an institutional database to identify all patients with a firm diagnosis of Marfan syndrome based on Ghent criteria. Inclusion required left ventricular ejection fraction (LVEF) to have been measured by both CMR and transthoracic echocardiography within 12 months of each other. Normal LVEF was defined as a value of >55% when measured by CMR. Velocity vector imaging was used to measure left ventricular longitudinal strain patterns by application of feature tracking to cine magnetic resonance images. Results were compared with data from 20 age-matched control subjects.

RESULTS

Sixty-nine Marfan syndrome patients met the inclusion criteria. The mean age was 35.4 ± 15.0 years, and 56.5% were male. The mean LVEF was 59.0% ± 7.0% by CMR and 59.1% ± 5.8% by echo. One-fifth of Marfan syndrome patients (15/69; 21.7%) had reduced function with LVEF ≤55% by CMR, but only 5 of these were identified by echo. Furthermore, echo identified 5 Marfan syndrome patients as having reduced LVEF in the presence of a normal LVEF by CMR. Some Marfan syndrome patients had abnormal longitudinal strain patterns even with LVEF within the reference range.

CONCLUSIONS

These data provide support for a primary cardiomyopathy in some Marfan syndrome patients. Cardiovascular magnetic resonance is more sensitive than echo for identifying cases with mild systolic dysfunction. Strain analysis may be more sensitive than simple LVEF assessment for identifying at-risk individuals.

Left Ventricular Systolic Function Assessed by Speckle Tracking Echocardiography in Athletes with and without Left Ventricle Hypertrophy

The aim of this study was to evaluate selected parameters of strain and rotation of the left ventricle (the basal rotation (BR) index, the basal circumferential strain (BCS) index, and the global longitudinal strain (GLS) of the left ventricle) in male athletes with physiological cardiac hypertrophy (LVH group), and athletes (non-LVH group) and non-athletes without hypertrophy (control group, CG). They were evaluated using transthoracic echocardiography and speckle tracking echocardiography before and after an incremental exercise test. The LVH group demonstrated lower BR at rest than the non-LVH group (p < 0.05) and the CG (p < 0.05). Physical effort had no effect on BR, nor was this effect different between groups (p > 0.05). There was a combined influence of LVH and physical effort on BR (F = 5.70; p < 0.05) and BCS (F = 4.97; p < 0.05), but no significant differences in BCS and GLS at rest between the groups. A higher BCS and lower GLS after exercise in the LVH group were demonstrated in comparison with the CG (p < 0.05). Left ventricular basal rotation as well as longitudinal and circumferential strains showed less of a difference between rest and after physical effort in subjects with significant myocardial hypertrophy. In conclusion, the obtained results may suggest that echocardiographic assessment of basal rotation and circumferential strain of the left ventricular can be important in predicting cardiac disorders caused by physical effort in individuals with physiological and pathological heart hypertrophy.

Speckle tracking echocardiography in cats with preclinical hypertrophic cardiomyopathy

Background

Cats with hypertrophic cardiomyopathy (HCM) have decreased left ventricular (LV) longitudinal deformation detected by mitral annular plane systolic excursion (MAPSE) and speckle tracking echocardiography. People with preclinical HCM have decreased systolic LV longitudinal and radial strain (S) and strain rate (SR), with preserved circumferential S and SR.

Hypothesis/Objectives

Cats with preclinical HCM have decreased systolic LV deformation compared to normal cats.

Animals

Seventy‐three client‐owned cats with (n = 37) and without (n = 36) preclinical HCM.

Methods

Retrospective echocardiographic study. Left and right ventricular longitudinal S and SR, LV radial and circumferential S and SR were calculated by STE. Left ventricular mass was also calculated. Correlation between STE variables and LV hypertrophy was determined and receiver‐operating characteristic (ROC) curves were plotted for prediction of HCM.

Results

Cats with HCM had smaller absolute longitudinal S (−14.8 ± 3.3% vs −19.7 ± 2.7%, P < .001), longitudinal SR (−2.36 ± 0.62 vs −2.95 ± 0.68 second⁻¹, P < .001), radial S (46.2 ± 21.3% vs 66.7 ± 17.6%, P < .001), and radial SR (5.60 ± 2.08 vs 6.67 ± 1.8 second⁻¹, P < .001) compared to healthy controls. No difference was observed for circumferential S and SR. Cats with HCM had greater LV mass (13.2 ± 3.7 g vs 8.6 ± 2.7 g, P < .001). The ROC with the greatest area under the curve (AUC) for the identification of HCM (0.974) was plotted from a logistic regression equation combining LV mass, MAPSE at the free wall, and LV internal diameter in diastole (LVIDd).

Conclusions and clinical importance

Cats with preclinical HCM have decreased long axis and radial deformation. Decreased longitudinal deformation and decreased LVIDd are factors that would support a diagnosis of HCM.

Five-year prognostic significance of global longitudinal strain in individuals with a hypertrophic cardiomyopathy gene mutation without hypertrophic changes

Background

Previous studies have reported that global longitudinal strain (GLS) is reduced in patients with hypertrophic cardiomyopathy (HCM) while left ventricular ejection fraction (LVEF) is normal. Our aim was to assess GLS in individuals with HCM mutations without hypertrophic changes and to determine its prognostic value for the development of HCM.

Methods and results

This retrospective case-control and cohort study included 120 HCM mutation carriers and 110 controls. GLS and LVEF were assessed with Tomtec Imaging software. Age, gender, and body surface area were similar in mutation carriers and controls. Compared to controls, mutation carriers had a higher maximal wall thickness (9 ± 2 vs 8 ± 2 mm, p < 0.001), higher LVEF (60 ± 5 vs 58 ± 4%, p < 0.001) and higher GLS (−21.4 ± 2.3% vs −20.3 ± 2.2%, p < 0.001). The GLS difference was observed in the mid-left ventricle (−21.5 ± 2.5% vs −19.9 ± 2.5%, p < 0.001) and the apex (−24.1 ± 3.5% vs −22.1 ± 3.4%, p < 0.001), but not in the base of the left ventricle (−20.0 ± 3.3% vs −20.0 ± 2.6%, p = 0.9). Echocardiographic follow-up was performed in 80 mutation carriers. During 5.6 ± 2.9 years’ follow-up, 13 (16%) mutation carriers developed HCM. Cox regression analysis showed age (hazard ratio (HR) 1.08, p = 0.01), pathological Q wave (HR 8.56; p = 0.01), and maximal wall thickness (HR 1.94; p = 0.01) to be independent predictors of the development of HCM. GLS was not predictive of the development of HCM (HR 0.78, p = 0.07).

Conclusion

GLS is increased in HCM mutation carriers without hypertrophic changes. GLS was of no clear prognostic value for the development of HCM during follow-up, in contrast to age, pathological Q waves and maximal wall thickness.

Electronic supplementary material

The online version of this article (10.1007/s12471-019-1226-5) contains supplementary material, which is available to authorized users.

Decreased biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy patients: implications for exercise capacity

The present study investigated the changes of biventricular mechanics at rest and during exercise and examined the association between exercise capacity and biventricular mechanics and functional reserve in nonobstructive hypertrophic cardiomyopathy (NHCM) patients. A total of 50 NHCM patients and 25 controls were consecutively recruited for this study. Using echocardiography and two-dimensional speckle-tracking imaging, an experienced echocardiographer determined the following indices: RV free wall longitudinal strain (RVFWLS), LV global longitudinal strain (LVGLS), strain rate (SR), and functional reserve of strain values. We also investigated the relationships between biventricular mechanics and exercise capacity using metabolic equivalents (METs). NHCM patients had lower RVFWLS, LVGLS, systolic SR, early diastolic SR, and systolic and diastolic reserve during exercise compared to controls. An association of biventricular mechanics (LVGLS, RVFWLS) with exercise capacity at rest and during exercise was established. Multivariable logistic regression revealed that RVFWLS and LVE/e' during exercise (RVFWLS-exe, E/e'-exe) were independent predictors of exercise intolerance. Receiver operating characteristic curve analysis indicated that LVE/e'-exe had a higher area under the curve for predicting exercise intolerance in NHCM patients. In hierarchical analysis, RVFWLS-exe provided an incremental predictive value of exercise intolerance over LVGLS during exercise (LVGLS-exe) and LVE/e'-exe. LVE/e'-exe also changed incrementally compared to LVGLS-exe and RVFWLS-exe. NHCM patients have decreased biventricular mechanics at rest and during exercise and impaired biventricular functional reserve, and biventricular mechanics are associated with functional capacity. We propose that simultaneous evaluation of biventricular function should provide incremental predictive value for exercise intolerance.

Layer-specific myocardial function in asymptomatic cats with obstructive hypertrophic cardiomyopathy assessed using 2-dimensional speckle-tracking echocardiography

Background

Hypertrophic cardiomyopathy (HCM), a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of layer‐specific myocardial function with 2D speckle‐tracking echocardiography in cats with asymptomatic HCM has not yet been reported.

Objectives

To quantitatively measure layer‐specific myocardial function of asymptomatic cats with HCM.

Animals

Ten client‐owned, asymptomatic cats with obstructive HCM and 13 healthy cats.

Methods

A retrospective, case‐control study. Cats underwent assessment of layer‐specific myocardial function (whole, endocardial, and epicardial) in the longitudinal and circumferential directions by using 2D speckle‐tracking echocardiography.

Results

Longitudinal strains were significantly lower in cats with HCM than controls in the whole (−15.5% vs −19.1%), endocardial (−18.3% vs −21.8%), and epicardial (−13.1% vs −16.8%) layers. Circumferential strains in whole and epicardial layers also were significantly lower in cats with HCM as compared with controls (−15.0% vs −20.2% and − 4.4% vs −9.4%, respectively). However, no significant difference was found between cats with HCM and controls in the global circumferential strain in the endocardial layer (−31.2% vs −34.2%). The circumferential endocardial‐to‐epicardial strain ratio was significantly higher in cats with HCM than in controls (6.1 vs 3.5).

Conclusions and Clinical Importance

Layer‐specific myocardial function assessed by 2D speckle‐tracking echocardiography differed in asymptomatic cats with obstructive HCM compared to controls despite their apparently normal systolic function, as determined by conventional echocardiography. The maintained endocardial circumferential strain and higher circumferential endocardial‐to‐epicardial strain ratio may reflect compensation for occult systolic dysfunction in cats with obstructive HCM.

Multilayer Myocardial Mechanics in Genotype-Positive Left Ventricular Hypertrophy-Negative Patients With Hypertrophic Cardiomyopathy

It is unknown whether the presence of a sarcomeric mutation alone is sufficient to result in abnormal myocardial force generation, or whether additional changes in myocardial architecture (hypertrophy, disarray, and fibrosis) are required to impair systolic function. Speckle tracking echocardiography allows quantification of global strain/strain rates, twist, and dyssynchrony. In the present study we sought to further elucidate early abnormalities of myocardial mechanics in sarcomeric mutation carriers without evidence of clinical disease. Sixty genotype-positive left ventricular hypertrophy-negative (G+left ventricular hypertrophy [LVH]-) patients and 60 normal controls were studied. Velocity vector imaging was applied retrospectively to echocardiographic images to quantify global longitudinal and circumferential strain/strain rate, and rotation parameters. The G+LVH- group demonstrated both smaller left ventricular diastolic cavity dimensions (4.5 ± 0.6 cm vs 4.8 ± 0.4 cm) and a higher LVEF (66 ± 6% vs 60 ± 5%) compared with controls. An increase in circumferential subendocardial systolic strain (-30 ± 5 vs -27 ± 3%) and both systolic and diastolic subendocardial strain rate was seen in the G+LVH- group. Peak rotation angles were higher at the base and apex, with an increase in total twist (9.0 ± 3.8 vs 6.9 ± 2.9). In the control group, global and average segmental strain were similar, suggesting no/minimal dyssynchrony (global mechanical synchrony index [GMSi] 0.97-0.98). In the G+LVH- group GMSi was significantly lower (subendocardial GMSi 0.95; subepicardial GMSi 0.60), suggesting increasing subendocardial to subepicardial dyssynchrony. In conclusion, utilizing multilayer strain analysis, we demonstrate that G+LVH- subjects have enhanced subendocardial systolic strain rate and twist, as well as mechanical dyssynchrony within the left ventricular myocardium. These results demonstrate that abnormalities in myocardial mechanics precede the development of clinical hypertrophy.

Layer-specific strain analysis of left ventricular myocardium after alcohol septal ablation for hypertrophic obstructive cardiomyopathy

INTRODUCTION

We aimed to explore the layer-specific systolic strain of left ventricular (LV) myocardium in patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after alcohol septal ablation (ASA).The routine 2D (frame rate: >50 Hz) data sets were acquired using GE Vivi7 system for 44 consecutive HOCM patients and 21 matched normal subjects. Fifteen of HOCM patients had serial echocardiograms available for speckle tracking analyses before and 1 year after ASA. 2D strain was analyzed by EchoPAC software.The layer strain from inner to mid-myocardial and outer layers in basal and middle segments in HOCM patients continuously declined. The absolute values of peak systolic strains from the endocardium to mid-myocardium and epicardium in the basal septum of the HOCM group were significantly lower than those of the normal group (P <.01). Meanwhile, the layer systolic strain of LV endocardium in the basal septum increased significantly during a 1-year follow-up (P <.05).

CONCLUSIONS

The layer-specific strains of HOCM patients measured by tissue Doppler echocardiography decreased significantly compared to those of normal individuals. The increased specific layer strain of LV endocardium in the basal septum may be a valid marker of echocardiographic improvement in HOCM patients receiving ASA.

Investigation of myocardial dysfunction using three-dimensional speckle tracking echocardiography in a genetic positive hypertrophic cardiomyopathy Chinese family

BACKGROUND

We previously reported four heterozygous missense mutations of MYH7, KCNQ1, MYLK2, and TMEM70 in a single three-generation Chinese family with dual Long QT and hypertrophic cardiomyopathy phenotypes for the first time. However, the clinical course among the family members was various, and the potential myocardial dysfunction has not been investigated.

OBJECTIVES

The objective of this study was to investigate the echocardiographic and electrocardiographic characteristics in a genetic positive Chinese family with hypertrophic cardiomyopathy and further to explore the association between myocardial dysfunction and electric activity, and the identified mutations.

METHODS

A comprehensive echocardiogram - standard two-dimensional Doppler echocardiography and three-dimensional speckle tracking echocardiography - and electrocardiogram were obtained for members in this family.

RESULTS

As previously reported, four missense mutations - MYH7-H1717Q, KCNQ1-R190W, MYLK2-K324E, and TMEM70-I147T - were identified in this family. The MYH7-H1717Q mutation carriers had significantly increased left ventricular mass indices, elevated E/e' ratio, deteriorated global longitudinal stain, but enhanced global circumferential and radial strain compared with those in non-mutation patients (all p<0.05). The KCNQ1-R190W carriers showed significantly prolonged QTc intervals, and the MYLK2-K324E mutation carriers showed inverted T-waves (both p<0.05). However, the TMEM70-I147T mutation carriers had similar echocardiography and electrocardiographic data as non-mutation patients.

CONCLUSIONS

Three of the identified four mutations had potential pathogenic effects in this family: MYH7-H1717Q was associated with increased left ventricular thickness, elevated left ventricular filling pressure, and altered myocardial deformation; KCNQ1-R190W and MYLK2-K324E mutations were correlated with electrocardiographic abnormalities reflected in long QT phenotype and inverted T-waves, respectively.

Challenging the complementarity of different metrics of left atrial function: insight from a cardiomyopathy-based study

Aims

Left ventricular (LV) strain provides incremental values to LV ejection fraction (LVEF) in predicting outcome. We sought to investigate if similar relationship is observed between left atrial (LA) emptying fraction and LA strain.

Methods and results

In this study, we selected 50 healthy subjects, 50 patients with dilated, 50 hypertrophic, and 50 infiltrative (light-chain (AL) amyloidosis) cardiomyopathy (CMP). Echocardiographic measures included LVEF and LA emptying fraction as well as LV and LA longitudinal strain (LVLS and LALS). After regression analysis, comparison of least square means of LA strain among aetiologies was performed. Intraclass correlation coefficient (ICC) and coefficient of variation (COV) were used in the assessment of variability and reproducibility of LV and LA metrics. The mean LVLS and all LA metrics were impaired in patients with all CMP compared with healthy subjects. In contrast to the moderate relationship between LVEF and LVLS (r = -0.51, P < 0.001), there was a strong linear relationship between LA emptying fraction and LA strain (r = 0.87, P < 0.001). In multiple regression analysis, total LA strain was associated with LVLS (β = -0.48, P < 0.001), lateral E/e' (β = -0.24, P < 0.001), age (β = -0.21, P < 0.001), and heart rate (β = -0.14, P = 0.02). The least square mean of LA strain adjusted for the parameters was not different among aetiologies (ANOVA P = 0.82). The ICC (>0.77) and COV (<13) were acceptable.

Conclusion

In contrast to LV measures, there is a strong linear relationship between volumetric and longitudinal deformation indices of left atrium irrespective of CMP aetiology. Either LA emptying fraction or LA strain could be used as an important parameter in predictive models.

Impaired cardiac and vascular motion in patients with Takayasu's arteritis: A velocity vector imaging-based study

OBJECTIVE

Takayasu's arteritis (TAK) is a chronic inflammatory vasculitis of the aorta and its major branches. In the present study, we aimed to evaluate the motion of the vascular wall and myocardial contractility by using a novel strain imaging method, velocity vector imaging (VVI), in patients with TAK. We also aimed to compare them with another inflammatory autoimmune disorder, systemic lupus erythematosus (SLE).

METHODS

We studied 33 patients with TAK, 18 patients with SLE, and 20 age- and sex-matched controls. All participants were subjected to carotid artery Doppler ultrasonography and transthoracic echocardiographic evaluation. VVI analysis was also performed to assess subclinical left ventricular (LV) systolic dysfunction and to determine tissue motion of the common carotid arteries (CCAs).

RESULTS

Aortic strain and distensibility were significantly impaired in patients with TAK, while the aortic stiffness and carotid artery stiffness indexes were increased. Aortic distensibility was the only parameter that was decreased among SLE patients. The values of CCA peak longitudinal strain, strain rate, and total longitudinal displacement (TLD) were also impaired in patients with TAK. Peak radial velocity was decreased while time-to-peak radial velocity was increased. In the SLE group, peak longitudinal strain, strain rate, TLD, and peak radial velocity were impaired. LV longitudinal peak systolic strain and strain rate were reduced in patients with TAK. Similarly, we revealed impaired subclinical LV systolic function in patients with SLE.

CONCLUSION

VVI is a novel strain imaging technique with additional value to determine early impairment in vascular and myocardial wall motion in patients with TAK.

Left Ventricular Wall Stress Is Sensitive Marker of Hypertrophic Cardiomyopathy With Preserved Ejection Fraction

Hypertrophic cardiomyopathy (HCM) patients present altered myocardial mechanics due to the hypertrophied ventricular wall and are typically diagnosed by the increase in myocardium wall thickness. This study aimed to quantify regional left ventricular (LV) shape, wall stress and deformation from cardiac magnetic resonance (MR) images in HCM patients and controls, in order to establish superior measures to differentiate HCM from controls. A total of 19 HCM patients and 19 controls underwent cardiac MR scans. The acquired MR images were used to reconstruct 3D LV geometrical models and compute the regional parameters (i.e., wall thickness, curvedness, wall stress, area strain and ejection fraction) based on the standard 16 segment model using our in-house software. HCM patients were further classified into four quartiles based on wall thickness at end diastole (ED) to assess the impact of wall thickness on these regional parameters. There was a significant difference between the HCM patients and controls for all regional parameters (P < 0.001). Wall thickness was greater in HCM patients at the end-diastolic and end-systolic phases, and thickness was most pronounced in segments at the septal regions. A multivariate stepwise selection algorithm identified wall stress index at ED (σ_i,ED) as the single best independent predictor of HCM (AUC = 0.947). At the cutoff value σ_i,ED < 1.64, both sensitivity and specificity were 94.7%. This suggests that the end-diastolic wall stress index incorporating regional wall curvature—an index based on mechanical principle—is a sensitive biomarker for HCM diagnosis with potential utility in diagnostic and therapeutic assessment.

A multidimensional sight on cardiac failure: uncovered from structural to molecular level

Heart failure is one of the leading causes of death, with high mortality rate within 5 years after diagnosis. Treatment and prognosis options for heart failure primarily targeted on hemodynamic and neurohumoral components that drive progressive deterioration of the heart. However, given the multifactorial background that eventually leads to the "phenotype" named heart failure, better insight into the various components may lead to personalized treatment opportunities. Indeed, currently used criteria to diagnose and/or classify heart failure are possibly too focused on phenotypic improvement rather than the molecular driver of the disease and could therefore be further refined by integrating the leap of molecular and cellular knowledge. The ambiguity of the ejection fraction-based classification criteria became evident with development of advanced molecular techniques and the dawn of omics disciplines which introduced the idea that disease is caused by a myriad of cellular and molecular processes rather than a single event or pathway. The fact that different signaling pathways may underlie similar clinical manifestations calls for a more holistic study of heart failure. In this context, the systems biology approach can offer a better understanding of how different components of a system are altered during disease and how they interact with each other, potentially leading to improved diagnosis and classification of this condition. This review is aimed at addressing heart failure through a multilayer approach that covers individually some of the anatomical, morphological, functional, and tissue aspects, with focus on cellular and subcellular features as an alternative insight into new therapeutic opportunities.

Early detection of myocardial dysfunction using two-dimensional speckle tracking echocardiography in a young cat with hypertrophic cardiomyopathy

Case summary

A 5-month-old intact female Scottish Fold cat was presented for cardiac evaluation. Careful auscultation detected a slight systolic murmur (Levine I/VI). The findings of electrocardiography, thoracic radiography, non-invasive blood pressure measurements and conventional echocardiographic studies were unremarkable. However, two-dimensional speckle tracking echocardiography revealed abnormalities in myocardial deformations, including decreased early-to-late diastolic strain rate ratios in longitudinal, radial and circumferential directions, and deteriorated segmental systolic longitudinal strain. At the follow-up examinations, the cat exhibited echocardiographic left ventricular hypertrophy and was diagnosed with hypertrophic cardiomyopathy using conventional echocardiography.

Relevance and novel information

This is the first report on the use of two-dimensional speckle tracking echocardiography for the early detection of myocardial dysfunction in a cat with hypertrophic cardiomyopathy; the myocardial dysfunction was detected before the development of hypertrophy. The findings from this case suggest that two-dimensional speckle tracking echocardiography can be useful for myocardial assessment when conventional echocardiographic and Doppler findings are ambiguous.

Left ventricular short-axis systolic function changes in patients with hypertrophic cardiomyopathy detected by two-dimensional speckle tracking imaging

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetic disease was characterised by left ventricular hypertrophy (LVH), myocardial fibrosis, fiber disarray. The short-axis systolic function is important in left ventricle function.

METHODS

Forty one healthy subjects and 37 HCM patients were enrolled for this research. Parasternal short-axis at the basal, middle, and apical levels were acquired by Echocardiography. The peak systolic circumferential strain of the endocardial, the middle and the epicardial layers, the peak systolic radial strain, and the peak systolic rotational degrees at different short-axis levels were measured by 2-dimensional speckle tracking imaging (2D-STI).

RESULTS

The peak systolic circumferential strain of the septum and anterior walls in HCM patients was significantly lower than normal subjects. All of the peak systolic radial strain in HCM patients was significantly lower than normal subjects. The rotational degrees at the base and middle short-axis levels in HCM patients were larger than normal subjects. The interventricular septal thickness in end-diastolic period correlated to the peak systolic circumferential strain of the septum wall.

CONCLUSIONS

The short-axis systolic function was impaired in HCM patients. The peak circumferential systolic strain of the different layers, peak systolic radial strain and rotation degrees of the different short-axis levels detected by 2D-STI are very feasible for assessing the short-axis function in HCM patients.

Determination of multidirectional myocardial deformations in cats with hypertrophic cardiomyopathy by using two-dimensional speckle-tracking echocardiography

Objectives Hypertrophic cardiomyopathy, a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of myocardial deformation with two-dimensional speckle-tracking echocardiography in cats with various stages of hypertrophic cardiomyopathy has not yet been reported. This study was designed to measure quantitatively multidirectional myocardial deformations of cats with hypertrophic cardiomyopathy. Methods Thirty-two client-owned cats with hypertrophic cardiomyopathy and 14 healthy cats serving as controls were enrolled and underwent assessment of myocardial deformation (peak systolic strain and strain rate) in the longitudinal, radial and circumferential directions. Results Longitudinal and radial deformations were reduced in cats with hypertrophic cardiomyopathy, despite normal systolic function determined by conventional echocardiography. Cats with severely symptomatic hypertrophic cardiomyopathy also had lower peak systolic circumferential strain, in addition to longitudinal and radial strain. Conclusions and relevance Longitudinal and radial deformation may be helpful in the diagnosis of hypertrophic cardiomyopathy. Additionally, the lower circumferential deformation in cats with severe hypertrophic cardiomyopathy may contribute to clinical findings of decompensation, and seems to be related to severe cardiac clinical signs. Indices of multidirectional myocardial deformations by two-dimensional speckle-tracking echocardiography may be useful markers and help to distinguish between cats with hypertrophic cardiomyopathy and healthy cats. Additionally, they may provide more detailed assessment of contractile function in cats with hypertrophic cardiomyopathy.

Heterogeneity of longitudinal and circumferential contraction in relation to late gadolinium enhancement in hypertrophic cardiomyopathy patients with preserved left ventricular ejection fraction

PURPOSE

To evaluate heterogeneity of myocardial contraction in relation to extensive late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) patients with preserved left ventricular ejection fraction, using fast strain-encoded magnetic resonance imaging.

MATERIALS AND METHODS

Twenty-two HCM patients and 24 age-matched control subjects were included in this retrospective study. The regional and global peak values of longitudinal and circumferential strain (LS_regional, LS_global, CS_regional, CS_global), and their regional heterogeneities were evaluated using coefficients of variation (LS_CoV, CS_CoV) in relation to LGE. Receiver operating characteristic curve analysis was performed to identify patients with a total left ventricular myocardial LGE ≥ 15%.

RESULTS

LS_global in HCM patients was significantly decreased compared to that in controls (- 14.4 ± 2.4% vs - 17.2 ± 2.0%; p = 0.0004), while CS_global was not (p = 1.0). Negative LGE segments demonstrated decreased LS_regional in HCM patients compared to in controls (p < 0.0001), while CS_regional was not decreased. CS_CoV demonstrated the largest area under the curve (AUC) (0.91), with high sensitivity (83%) and specificity (94%) for detection of HCM patients with extensive LGE, while the AUC of LS_CoV was low (0.49).

CONCLUSION

The heterogeneity in CS_regional has a high diagnostic value for detection of HCM patients with extensive LGE.

The Remarkable 50 Years of Imaging in HCM and How it Has Changed Diagnosis and Management: From M-Mode Echocardiography to CMR

The almost 50-year odyssey of cardiac imaging in hypertrophic cardiomyopathy (HCM), revisited and described here, has been remarkable, particularly when viewed in the timeline of advances that occurred during a single generation of investigators. At each step along the way, from M-mode to 2-dimensional echocardiography to Doppler imaging, and finally over the last 10 years with the emergence of high-resolution tomographic cardiac magnetic resonance (CMR), evolution of the images generated by each new technology constituted a paradigm change over what was previously available. Together, these advances have transformed the noninvasive diagnosis and management of HCM in a number of important clinical respects. These changes include a more complete definition of the phenotype, resulting in more reliable clinical identification of patients and family members, defining mechanisms (and magnitude) of left ventricular outflow obstruction, and novel myocardial tissue characterization (including in vivo detection of fibrosis/scarring); notably, these advances afford more precise recognition of at-risk patients who are potential candidates for life-saving primary prevention defibrillator therapy. This evolution in imaging as applied to HCM has indelibly changed cardiovascular practice for this morphologically and clinically complex genetic disease.

Incremental Prognostic Utility of Left Ventricular Global Longitudinal Strain in Hypertrophic Obstructive Cardiomyopathy Patients and Preserved Left Ventricular Ejection Fraction

BACKGROUND

In obstructive hypertrophic cardiomyopathy patients with preserved left ventricular (LV) ejection fraction, we sought to determine whether LV global longitudinal strain (LV-GLS) provided incremental prognostic utility.

METHODS AND RESULTS

We studied 1019 patients with documented hypertrophic cardiomyopathy (mean age, 50±12 years; 63% men) evaluated at our center between 2001 and 2011. We excluded age <18 years, maximal LV outflow tract gradient <30 mm Hg, bundle branch block or atrial fibrillation, past pacemaker/cardiac surgery, including myectomy/alcohol ablation, and obstructive coronary artery disease. Average resting LV-GLS was measured offline on 2-, 3-, 4-chamber views using Velocity Vector Imaging (Siemens, Malvern, PA). Outcome was a composite of cardiac death and appropriate internal defibrillator (implantable cardioverter defibrillator) discharge. Maximal LV thickness, LV ejection fraction, indexed left atrial dimension, rest and maximal LV outflow tract gradient, and LV-GLS were 2.0±0.2 cm, 62±4%, 2.2±4 cm/m2, 52±42 mm Hg, 103±36 mm Hg, and -13.6±4%. During 9.4±3 years of follow-up, 668 (66%), 166 (16%), and 122 (20%), respectively, had myectomy, atrial fibrillation, and implantable cardioverter defibrillator implantation, whereas 69 (7%) had composite events (62 cardiac deaths). Multivariable competing risk regression analysis revealed that higher age (subhazard ratio, 1.04 [1.02-1.07]), AF during follow-up (subhazard ratio, 1.39 [1.11-1.69]), and worsening LV-GLS (subhazard ratio, 1.11 [1.05-1.22]) were associated with worse outcomes, whereas myectomy (subhazard ratio, 0.44 [0.25-0.72]) was associated with improved outcomes (all P<0.01). Sixty-one percent of events occurred in patients with LV-GLS worse than median (-13.7%).

CONCLUSIONS

In obstructive hypertrophic cardiomyopathy patients with preserved LV ejection fraction, abnormal LV-GLS was independently associated with higher events, whereas myectomy was associated with improved outcomes.

Left-ventricular mechanics in children with hypertrophic cardiomyopathy. CMR study

OBJECTIVES

To assess the magnitude of myocardial displacement abnormalities and their alterations with the fibrosis, left-ventricular (LV) outflow tract obstruction (LVOTO) and hypertrophy in juveniles with hypertrophic cardiomyopathy (HCM).

STUDY DESIGN

Fifty-five children [age 12,5±4.6years, 38 (69,1%) males, 19 (34,5%) with LVOTO] with HCM and 20 controls underwent cardiovascular magnetic resonance. The LV feature tracking (FT) derived strain and strain rates were quantified. Results of FT analysis were compared between HCM subjects and controls and between children with and without LVOTO.

RESULTS

Children with HCM exhibited decreased strain in both hypertrophied and nonhypertrophied segments versus controls. LV global longitudinal strain (LVGLS) rate (-0.69±0.04 vs -0.91±0.05, p=0,04), LV circumferential strain (LVCR) rate (-0.98±0.09 vs -1.27±0.06, p=0,02), LV radial strain (LVR) (18,5±1.9 vs 27,4±1.4, p<0,01) and LVR rate (0,98±0.1 vs 1,53±0.08, p<0,01) were substantially compromised in subjects with LVOTO vs without. In multivariable regression all LV myocardial dynamics markers, except for LVCR, exhibited a significant association with the degree of LVOTO. LVCR rate (β=0,31, p=0,02) and LVR (β=-0.24, p=0,04) were related to LV mass and only LVCR rate (β=0,15, p=0,03) was associated with the amount of LV fibrosis.

CONCLUSIONS

The reduction of all indices of LV myocardial mechanics in juvenile HCM patients was global but particularly pronounced in hypertrophied segments of the LV. The majority of the LV strains and strain rates were substantially compromised in subjects with LVOTO compared to patients without the obstruction. Myocardial mechanics indices seemed to be related to the degree of LVOTO rather than either to mass or the amount of fibrosis.