Incremental value of left atrial active function measured by speckle tracking echocardiography in patients with hypertrophic cardiomyopathy

Diagnostic value of cardiac magnetic resonance imaging-based left atrial strain analysis for identifying cardiac diseases with overlapping phenotype

BACKGROUND

The main objective of this study was to compare diagnostic accuracies of cardiac magnetic resonance (CMR)-based left atrial (LA) volumetry and function, including LA strain analysis, for the detection of myocardial impairments in diseases of different etiologies such as hypertensive heart disease, Fabry disease and acute myocarditis.

METHODS

Healthy volunteers (HV, n = 50) and patients with cardiomyopathies (n = 140), including patients with hypertensive heart disease (n = 40), Fabry disease (n = 49), and acute myocarditis (n = 51), underwent CMR at 3 T. Atrial volume and strain analysis based on long-axis cine acquisition was performed using a commercially available post-processing software.

RESULTS

Patients exhibited impaired LA reservoir (28.60 ± 9.91 % vs. 41.27 ± 7.54 %), conduit (17.35 ± 7.72 % vs. 26.89 ± 5.25 %) and booster strain (11.30 ± 4.52 % vs. 14.61 ± 4.15 %) parameters compared to HV (all p < 0.001). In contrast, the volumetric values showed no significant difference between patients and HV (p > 0.05). Passive and total emptying fractions were significantly lower in patients (p < 0.001), while active emptying fraction did not differ (p > 0.05). Superior diagnostic accuracy for the LA reservoir strain demonstrated improved prognostic performance comparing to LA volumetric and functional parameters (area under the curve [AUC] 0.85 vs. e.g. passive emptying fraction AUC 0.78, p < 0.05).

CONCLUSION

LA strain parameters effectively distinguish patients with cardiac diseases presenting overlapping phenotypes from HV and outperform volumetric and traditional functional assessments of the LA.

Left atrial remodelling and function in various left ventricular hypertrophic phenotypes

AIMS

How the underlying aetiology and pathophysiology of left ventricular (LV) hypertrophy affects left atrial (LA) remodelling and function remains unexplored. The present study aims to investigate the influence of various hypertrophic phenotypes on LA remodelling and function.

METHODS AND RESULTS

Patients with LV hypertrophy who underwent cardiac magnetic resonance (CMR) were compared to a control group. CMR data were analysed retrospectively to assess LA strain, volume, sphericity, and left atrioventricular coupling index (LACI). Independent clinical associates of LA strain were assessed using multivariable linear regression analysis. A total of 375 individuals were included: 148 with hypertrophic cardiomyopathy (HCM), 35 with cardiac amyloidosis (CA), 41 with hypertensive (HTN) heart disease, 97 with severe asymptomatic aortic stenosis (AS), and 54 with normal CMR. Indexed LA end-systolic (iLVmax), diastolic volumes, and LA sphericity were the largest in patients with CA (59.1 ± 16.9 mL/m2, 46.8 ± 16.4 mL/m2, and 83.2 ± 2.1%, respectively). Patients with CA presented a higher LACI when compared with other groups (58 ± 2% vs. 42 ± 2% in HCM, 39 ± 2% in HTN heart disease, 37 ± 2% in AS, and 22 ± 1% in normal), while no differences were observed across others. Patients with CA showed the lowest LA reservoir [9.6% (0.6-18.6%)] and booster strain (9.1 ± 5.4%), whereas no differences were observed across other groups. LACI and iLAVmax were independently correlated with LA reservoir (β = 0.15 and β = -39.33, respectively), LA conduit (β = 0.08 and β = -17.08, respectively), and LA booster strains (β = 0.1 and β = -28.69, respectively). LA sphericity was independently correlated with LA reservoir strain (β = -0.51). Finally, LV global longitudinal strain was independently correlated with LA reservoir (β = -0.43), conduit (β = -0.20), and booster strain (β = -0.24).

CONCLUSION

LA characteristics differ among LV hypertrophic phenotypes. LACI and iLAVmax are independently correlated with LA function, while LA sphericity correlates independently with LA reservoir strain.

Speckle Tracking Echocardiography-Based Correlation Between Left Atrial Strain and Functional Capacity in Patients With Hypertrophic Cardiomyopathy

INTRODUCTION

The left atrium (LA) dilates and its function decreases as a chronic secondary change in hypertrophic cardiomyopathy (HCM). LA strain is a more sensitive measure of LV filling pressure than LA volume and can be used to predict the functional capacity in HCM.

OBJECTIVE

To analyze LA strain in patients with HCM and its correlation with exercise tolerance.

METHODS

A total of 113 patients with HCM were enrolled. All patients underwent detailed clinical evaluation, 24-h Holter monitoring, exercise stress testing, two-dimensional echocardiography with LA strain analysis using speckle tracking imaging. Assessment of functional capacity was done in terms of metabolic equivalents (METs). HCM patients with METS >6.0 were included in Group A while those with METS ≤ 6.0 were included Group B. Correlation of various parameters of LA strain (left atrial reservoir strain [LASr], left atrial conduit strain [LAScd], and left atrial contraction strain [LASct]) was done with functional capacity.

RESULTS

The mean age of the study population was 47 ± 10.77 years with the majority of them being males (71.9%). Group B patients had significantly lower LASr (12.95% ± 8.61% vs. 22.16% ± 16%; p < 0.001), LAScd (-7.28% ± 6.29% vs. -12.74% ± 8.40%; p < 0.001), and LASct (-7.44 ± 4.46 vs. -11.19 ± 6.53; p < 0.001). Multivariable linear regression analysis reported LASr to be an independent predictor of METs and had a quadratic relationship with log-odds with negative linear and positive quadratic coefficients. LASr was the strongest echocardiographic predictor of reduced METS with an AUC of 0.78 (95% confidence interval [CI]: 0.68-0.88), sensitivity of 71.8%, and specificity of 82.9%.

CONCLUSION

LA strain parameters are associated with functional capacity in patients with HCM with lower LA strain values being associated with poor functional capacity.

Abnormal left atrial strain and left atrial stiffness index are associated with adverse outcomes in children with cardiomyopathies: a pilot study

Conventional diastolic dysfunction parameters seem to be imperfect when applied to the pediatric cardiomyopathy population. The aim of this pilot study was to search for novel echocardiographic parameters associated with adverse outcomes in children with the most common cardiomyopathies. Fifty-six patients with pediatric cardiomyopathies (28 with dilated, 21 with hypertrophic, 7 with left ventricular non-compaction cardiomyopathy) and 28 healthy subjects were included in the study. Left atrial reservoir (LASr), conduit (LAScd) and contraction (LASct) strain, left atrial stiffness index (LASI), as well as conventional diastolic dysfunction parameters were measured using echocardiography. Adverse outcomes were defined as heart failure (including heart transplant) and arrhythmic endpoints. Patients with adverse outcomes presented with significantly lower LASr (16.68% ± 8.64% vs. 33.97% ± 9.99%, p-value < 0.001), lower LAScd (- 10.37% ± 5.83% vs. - 25.50% ± 9.24%, p-value < 0.001) and higher values of LASI (0.69 [IQR 0.34; 1.11] vs. 0.21 [IQR 0.16; 0.31], p-value < 0.001). LASr < 20%, LAScd ≥ - 12%, and LASI ≥ 0.26 were all associated with reduced survival. LASr, LAScd and LASI seem to be promising parameters in predicting adverse outcomes in the most common pediatric cardiomyopathies. Left atrial strain parameters and LASI are helpful in differentiating healthy control subjects from children with hypertrophic and dilated cardiomyopathies.

Incremental diagnostic and prognostic utility of left atrial deformation in heart failure using speckle tracking echocardiography

Left atrium (LA) is a very important component of cardiovascular performance. The assessment of LA function has gathered the interest with expanding research supporting the utility as a biomarker for outcomes in heart failure (HF). Echocardiography is the main imaging modality which helps in a qualitative and quantitative assessment of the LA size and function. Recent advances in probe technology and software analysis have provided a better understanding of LA anatomy, physiology, pathology, and function. A variety of parameters have been defined as markers of LA function but there is no single parameter that best defines LA function. Speckle tracking echocardiography-derived analysis of LA deformation provides a window on all phases of LA function (reservoir, conduit, and booster pump). There is accumulative published data that supported the diagnostic and prognostic values of LA deformation integration during echo assessment of LA in HF. This review article summarized the clinical utility of LA deformation that may help in prediction, diagnosis, categorization, risk stratification, and guiding the proper selection of therapy in HF patients in daily practice.

A systematic review and meta-analysis of left atrial strain in hypertrophic cardiomyopathy and its prognostic utility

Despite advances in noninvasive imaging modalities to identify atrial fibrillation (AF) risk in Hypertrophic Cardiomyopathy (HCM), there is a paucity of evidence concerning the impact of low Left Atrial strain (LAS) on AF and major adverse cardiac events (MACE) incidence in these patients. This study investigated the diagnostic and prognostic significance of LAS in predicting AF and MACE in HCM. Findings revealed lower LA reservoir (MD: -11.79, 95% CI -14.83, -8.74; p<0.00001), booster (MD: -4.10, 95% CI -6.29, -1.91; p=0.0002), and conduit (MD: -7.52, 95% CI -9.39, -5.65; p<0.00001) strains in HCM patients versus healthy controls, and also indicated a significant association between low LA reservoir/conduit/booster strain and the development of new AF as well as MACE prevalence in HCM patients. The results from this study suggest the valuable role of LA strain in HCM and its utility in predicting the development of new AF and cardiac events in HCM patients.

Echocardiographic Phenotypes of Subclinical Organ Damage: Clinical and Prognostic Value in the General Population. Findings from the Pamela Study

Subclinical alterations in cardiac structure and function include a variety of abnormal phenotypes of established adverse prognostic significance such as left ventricular hypertrophy (LVH), alterations of LV geometry, left atrial (LA) enlargement, and aortic root (AR) dilatation. The excess cardiovascular (CV) risk associated with these phenotypes has been consistently demonstrated in different clinical settings such in patients with systemic hypertension, coronary heart disease, diabetes mellitus, chronic kidney disease, heart failure and in geneal population samples. The Pressioni Monitorate e Loro Associazioni (PAMELA), a longitudinal population-based study originally designed to assess the normality values, prognostic significance of office, home and 24-hour blood pressure, including among the many clinical and laboratory variables the collection of echocardiographic data, allowed to gather important information on the clinical prognostic significance of subclinical cardiac damage during a long follow-up period. This article summarizes the original findings provided by the PAMELA study on the clinical correlates and prognostic significance of echocardiographic markers of subclinical organa damage namely LVH, left atrial enlargement (LA) and AR dilatation at the community level.

Left Atrial Strain Imaging by Speckle Tracking Echocardiography: The Supportive Diagnostic Value in Cardiac Amyloidosis and Hypertrophic Cardiomyopathy

Background: Left atrial (LA) function is crucial for assessing left ventricular filling in various cardiovascular conditions. Cardiac Amyloidosis (CA) is characterized by atrial myopathy and LA function impairment, with diastolic dysfunction up to restrictive filling pattern, leading to progressive heart failure and arrhythmias. This study evaluates LA function and deformation using speckle tracking echocardiography (STE) in patients with CA compared to a cohort of patients with sarcomeric Hypertrophic Cardiomyopathy (HCM) and a control group. Methods: We conducted a retrospective, observational study (from January 2019 to December 2022) including a total of 100 patients: 33 with ATTR-CA, 34 with HCMs, and 33 controls. Clinical evaluation, electrocardiograms, and transthoracic echocardiography were performed. Echocardiogram images were analyzed in post-processing using EchoPac software for LA strain quantification, including LA-reservoir, LA-conduit, and LA-contraction strain. Results: The CA group exhibited significantly impaired LA function compared to HCMs and control groups, with LA-reservoir median values of -9%, LA-conduit -6.7%, and LA-contraction -3%; this impairment was consistent even in the CA subgroup with preserved ejection fraction. LA strain parameters correlated with LV mass index, LA volume index, E/e', and LV-global longitudinal strain and were found to be associated with atrial fibrillation and exertional dyspnea. Conclusions: LA function assessed by STE is significantly impaired in CA patients compared to HCMs patients and healthy controls. These findings highlight the potential supportive role of STE in the early detection and management of the disease.

Different phenotype of left atrial function impairment in patients with hypertrophic cardiomyopathy and hypertension: comparison of healthy controls

Background

The impairment of atrial function and atrial-ventricular coupling in diseases with left ventricular (LV) hypertrophy has been increasingly recognized. This study compares left atrium (LA) and right atrium (RA) function, as well as LA-LV coupling, in patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) with preserved LV ejection fraction (EF), using cardiovascular magnetic resonance feature tracking (CMR-FT).

Methods

Fifty-eight HCM patients, 44 HTN patients, and 25 healthy controls were retrospectively enrolled. LA and RA functions were compared among the three groups. LA-LV correlations were evaluated in the HCM and HTN groups.

Results

LA reservoir (LA total EF, ɛs, and SRs), conduit (LA passive EF, ɛe, SRe), and booster pump (LA booster EF, ɛa, SRa) functions were significantly impaired in HCM and HTN patients compared to healthy controls (HCM vs. HTN vs. healthy controls: ɛs, 24.8 ± 9.8% vs. 31.3 ± 9.3% vs. 25.2 ± 7.2%; ɛe, 11.7 ± 6.7% vs. 16.8 ± 6.9% vs. 25.5 ± 7.5%; ɛa, 13.1 ± 5.8% vs. 14.6 ± 5.5% vs. 16.5 ± 4.5%, p < 0.05). Reservoir and conduit functions were more impaired in HCM patients compared to HTN patients (p < 0.05). LA strains demonstrated significant correlations with LV EF, LV mass index, LV MWT, global longitudinal strain parameters, and native T1 in HCM patients (p < 0.05). The only correlations in HTN were observed between LA reservoir strain (ɛs) and booster pump strain (ɛa) with LV GLS (p < 0.05). RA reservoir function (RA ɛs, SRs) and conduit function (RA ɛe, SRe) were significantly impaired in HCM and HTN patients (p < 0.05), while RA booster pump function (RA ɛa, SRa) was preserved.

Conclusions

LA functions were impaired in HCM and HTN patients with preserved LV EF, with reservoir and conduit functions more affected in HCM patients. Moreover, different LA-LV couplings were apparent in two different diseases, and abnormal LA-LV coupling was emphasized in HTN. Decreased RA reservoir and conduit strains were evident in both HCM and HTN, while booster pump strain was preserved.

Predictive value of left atrial strain analysis in adverse clinical events in patients with hypertrophic cardiomyopathy: a CMR study

BACKGROUND

A subset of patients with hypertrophic cardiomyopathy (HCM) will experience adverse clinical events such as heart failure (HF), cardiovascular death, and new-onset atrial fibrillation (AF). Current risk stratification methods are imperfect and limit the identification of patients at high risk for HCM. This study aimed to evaluate the role of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in the occurrence of adverse clinical events in patients with HCM.

METHODS

Left atrial (LA) structural, functional, and strain parameters were evaluated in 99 patients with HCM and compared with 89 age-, sex-, and BMI-matched control subjects. LA strain parameters were derived from CMR two- and four-chamber cine images by a semiautomatic method. LA strain parameters include global longitudinal strain (GLS) and global circumferential strain (GCS). The LA GLS includes reservoir strain (GLS reservoir), conduit strain (GLS conduit), and booster strain (GLS booster). Three LA GLS strain rate (SR) parameters were derived: SR reservoir, SR conduit, and SR booster. The primary endpoint was set as a composite of adverse clinical events, including SCD, new-onset or worsening to hospitalized HF, new-onset AF, thromboembolic events, and fatal ventricular arrhythmias.

RESULTS

LA GLS, GLS SR and GCS were impaired in HCM patients compared to control subjects (all p < 0.001). After a mean follow-up of 37.94 ± 23.69 months, 18 HCM patients reached the primary endpoint. LA GLS, GLS SR, and GCS were significantly lower in HCM patients with adverse clinical events than in those without adverse clinical events (all p < 0.05). In stepwise multiple Cox regression analysis, LV SV, LA diameter, pre-contraction LAV (LAV pre-ac), passive LA ejection fraction (EF), and LA GLS booster were all independent determinants of adverse clinical events. LA GLS booster ≤ 8.9% was the strongest determinant (HR = 8.9 [95%CI (1.951, 40.933)], p = 0.005). Finally, LA GLS booster provided predictive adverse clinical events value (AUC = 0.86 [95%CI 0.77-0.98]) that exceeded traditional outcome predictors.

CONCLUSION

LA strain assessment, a measure of LA function, provides additional predictive information for established predictors of HCM patients. LA GLS booster was independently associated with adverse clinical events in patients with HCM.

Prognostic significance of left atrial strain in sarcomere gene variant carriers without hypertrophic cardiomyopathy

Background

Genetic testing of relatives of hypertrophic cardiomyopathy (HCM) patients has led to a large group of genotype‐positive, phenotype‐negative (G+/Ph−) subjects. Prediction of progression to overt HCM in these subjects is challenging. While left atrial (LA) strain is reduced in HCM patients it is currently unknown whether this parameter can be used to predict HCM phenotype progression.

Methods

This study includes 91 G+/Ph− subjects and 115 controls. Standard echocardiographic parameters as well as left ventricular global longitudinal strain (LV GLS) and LA reservoir strain (LASr) were assessed for each patient. Logistic and Cox proportional hazard regression analyses were used to investigate predictors of G+/Ph− status and HCM during follow‐up.

Results

Independent predictors of G+ status included pathological Q waves (OR 1.60 [1.15–2.23], p < .01), maximal wall thickness (MWT: OR 1.10 [1.07–1.14], p < .001), mitral inflow E wave (OR 1.06 [1.02–1.10, p = .001), A wave (OR 1.06 [1.03–1.10], p < .001), LV GLS (OR .96 [.94–.98], p < .001), and LASr (OR .99 [.97–.99], p = .03). In univariable Cox regression analysis, male sex (HR 2.78 [1.06–7.29], p = .04), MWT (HR 1.72 [1.14–2.57], p = .009) and posterior wall thickness (HR 1.65 [1.17–2.30], p = .004) predicted HCM during a median follow‐up of 5.9 [3.2–8.6] years, whereas LASr did not (HR .95 [.89–1.02], p = .14). There were no significant predictors of HCM after multivariable adjustment.

Conclusion

LASr is significantly impaired in G+/Ph− subjects and is an independent predictor of G+/Ph− status, but did not predict HCM development during follow‐up.

Association Between Heart Failure With Preserved Left Ventricular Ejection Fraction and Impaired Left Atrial Phasic Function in Hypertrophic Cardiomyopathy: Evaluation by Cardiac MRI Feature Tracking

BACKGROUND

The majority of heart failure (HF) in hypertrophic cardiomyopathy (HCM) manifests as a phenotype with preserved left ventricular (LV) ejection fraction; however, the exact contribution of left atrial (LA) phasic function to HF with preserved ejection fraction (HFpEF) in HCM remains unresolved.

PURPOSE

To define the association between LA function and HFpEF in HCM patients using cardiac magnetic resonance imaging (MRI) feature tracking.

STUDY TYPE

Retrospective.

POPULATION

One hundred and fifty-four HCM patients (HFpEF vs. non-HF: 55 [34 females] vs. 99 [43 females]).

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession.

ASSESSMENT

LA reservoir function (reservoir strain [ε_s ], total ejection fraction [EF]), conduit function (conduit strain [ε_e ], passive EF), booster-pump function (booster strain [ε_a ] and active EF), LA volume index, and LV global longitudinal strain (LV GLS) were evaluated in HCM patients.

STATISTICAL TESTS

Chi-square test, Student's t-test, Mann-Whitney U test, multivariate linear regression, logistic regression, and net reclassification analysis were used. Two-sided P < 0.05 was considered statistically significant.

RESULTS

No significant difference was found in LV GLS between the non-HF and HFpEF group (-10.67 ± 3.14% vs. -10.14 ± 4.01%, P = 0.397), whereas the HFpEF group had more severely impaired LA phasic strain (ε_s : 27.40 [22.60, 35.80] vs. 18.15 [11.98, 25.90]; ε_e : 13.80 [9.20, 18.90] vs. 7.95 [4.30, 14.35]; ε_a : 13.50 [9.90, 17.10] vs. 7.90 [5.40, 14.15]). LA total EF (37.91 [29.54, 47.94] vs. 47.49 [39.18, 55.01]), passive EF (14.70 [7.41, 21.49] vs. 18.07 [9.32, 24.78]), and active EF (27.19 [17.79, 36.60] vs. 36.64 [26.63, 42.71]) were all significantly decreased in HFpEF patients compared with non-HF patients. LA reservoir (β = 0.90 [0.85, 0.96]), conduit (β = 0.93 [0.87, 0.99]), and booster (β = 0.86 [0.78, 0.95]) strain were independently associated with HFpEF in HCM patients. The model including reservoir strain (Net Reclassification Index [NRI]: 0.260) or booster strain (NRI: 0.325) improved the reclassification of HFpEF based on LV GLS and minimum left atrial volume index (LAVI_min ).

DATA CONCLUSION

LA phasic function was severely impaired in HCM patients with HFpEF, whereas LV function was not further impaired compared with non-HF patients.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 3.

Incremental value of left atrial booster and reservoir strain in predicting atrial fibrillation in patients with hypertrophic cardiomyopathy: a cardiovascular magnetic resonance study

BACKGROUND

Left atrial (LA) size and function are known predictors of new onset atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients. Components of LA deformation including reservoir, conduit, and booster function provide additional information on atrial mechanics. Whether or not LA deformation can augment our ability to predict the risk of new onset AF in HCM patients beyond standard measurements is unknown.

METHODS

We assessed LA size, function, and deformation on cardiovascular magnetic resonance (CMR) in 238 genotyped HCM patients and compared this with twenty age, sex, blood pressure and body mass index matched control subjects. We further evaluated the determinants of new onset AF in HCM patients.

RESULTS

Compared to control subjects, HCM patients had higher LA antero-posterior diameter, lower LA ejection fraction and lower LA reservoir (19.9 [17.1, 22.2], 21.6 [19.9, 22.9], P = 0.047) and conduit strain (10.6 ± 4.4, 13.7 ± 3.3, P = 0.002). LA booster strain did not differ between healthy controls and HCM patients, but HCM patients who developed new onset AF (n = 33) had lower booster strain (7.6 ± 3.3, 9.5 ± 3.0, P = 0.001) than those that did not (n = 205). In separate multivariate models, age, LA ejection fraction, and LA booster and reservoir strain were each independent determinants of AF. Age ≥ 55 years was the strongest determinant (HR 6.62, 95% CI 2.79-15.70), followed by LA booster strain ≤ 8% (HR 3.69, 95% CI 1.81-7.52) and LA reservoir strain ≤ 18% (HR 2.56, 95% CI 1.24-5.27). Conventional markers of HCM phenotypic severity, age and sudden death risk factors were associated with LA strain components.

CONCLUSIONS

LA strain components are impaired in HCM and, together with age, independently predicted the risk of new onset AF. Increasing age and phenotypic severity were associated with LA strain abnormalities. Our findings suggest that the routine assessment of LA strain components and consideration of age could augment LA size in predicting risk of AF, and potentially guide prophylactic anticoagulation use in HCM.

Echocardiographic evaluation of hypertrophic cardiomyopathy: A review of up-to-date knowledge and practical tips

Hypertrophic cardiomyopathy (HCM) is the most frequent cardiac disease with genetic substrate, affecting about .2%-.5% of the population. The proper diagnosis is important for optimal management and follow-up. Echocardiography plays an essential role in the assessment of patients with HCM including diagnosis, screening, management formulation, prognosis, and follow up. It also helps to differentiate HCM from other diseases. The advancement of software and probe technology added many echo modalities and techniques that helped in refining the diagnostic and assessing the prognosis of patients with HCM. In this review, we briefly summarize how to integrate the different echocardiographic modalities to obtain comprehensive assessment supported by an updated knowledge of the latest guidelines and recently published articles. Many practical tips and tricks are included in this review to improve the diagnostic accuracy of echocardiography and minimize errors during interpretation.

Comprehensive Echocardiography of Left Atrium and Left Ventricle Using Modern Techniques Helps in Better Revealing Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) is an important arrhythmia in hypertrophic cardiomyopathy (HCM). We aimed to explore whether a complex evaluation of the left ventricle (LV) using modern echocardiography techniques, additionally to the left atrium (LA) boosts the probability of AF diagnosis. Standard echocardiography, 2D and 3D speckle tracking, were performed for LA and LV evaluation in HCM patients and healthy volunteers. Of 128 initially qualified HCM patients, 60 fulfilled included criteria, from which 43 had a history of AF, and 17 were without AF. LA volume index and peak strain, LV ejection fraction, and strains were significant predictors of AF. In addition, 2D global longitudinal strain (GLS) for LV at cut off -16% turned out to be the most accurate predictor of AF (OR 48.00 [95% CI 2.68-859.36], p = 0.001), whereas the combination of LA peak strain ≤ 22% and LV GLS ≥ -16% had the highest discriminatory power (OR 76.36 [95% CI 4.13-1411.36], p = 0.001). AF in HCM patients seems to be LA as well as LV disease. Revealing lower strain for LV, in addition to lower LA strain, may have an important impact on accurate characteristics of HCM patients with AF history.

Contemporary narrative review on left atrial strain mechanics in echocardiography: cardiomyopathy, valvular heart disease and beyond

Left atrial (LA) strain mechanics refer to the measurement of LA myocardial deformation expressed as a percentage, and have been gathering interest over the last decade with expanding research supporting their utility in multiple cardiovascular disorders. Measured through advanced dynamic imaging techniques which include tissue Doppler imaging (TDI) and two-dimensional (2D) speckle tracking echocardiography (STE), LA strain mechanics are affected by left ventricular diastolic dysfunction prior to the onset of functional and structural changes in the left ventricle (LV). There is a need for practising cardiologists to become more familiar with the clinical utility of LA strain mechanics. In this article, we begin by reviewing the physiologic function of the LA, using this as a basis for understanding LA strain mechanics. The focus of this review article is to provide a contemporary update on the utility of LA strain mechanics in a range of cardiovascular disorders, including atrial fibrillation (AF), hypertrophic cardiomyopathy (HCM), valvular pathologies, coronary artery disease (CAD) as well as systemic diseases, such as hypertension (HTN), obesity and diabetes mellitus (DM). This article also highlights the current limitations in more widespread clinical applications of LA strain mechanics, as well as outlining the future perspectives on the clinical applications of LA strain mechanics.

Left Atrial Strain and Function in Pediatric Hypertrophic Cardiomyopathy

BACKGROUND

Left atrial (LA) strain and dysfunction are early markers of diastolic dysfunction, associated with poor exercise capacity in adults with hypertrophic cardiomyopathy (HCM). Literature on assessment of LA mechanics in pediatric HCM is lacking. The aim of this study was to assess LA strain and LA function in pediatric patients who have HCM with (phenotype positive [P+]) and without (genotype positive, phenotype negative [G+P-]) ventricular hypertrophy and evaluate their correlation with exercise stress test parameters.

METHODS

Seventy-eight children (3-25 years of age) with HCM (P+, n = 46; G+P-, n = 32) and 20 healthy control subjects were retrospectively studied. LA conduit function, reservoir function, and pump function were computed using phasic LA volumetric analysis. LA reservoir strain (LASr) and LA contractile strain were measured using speckle-tracking echocardiography. Exercise test findings within 12 months of echocardiography were recorded.

RESULTS

LA conduit function (36% vs 48%, P < .001) and LA reservoir function (137% vs 180%, P < .001) were lower in P+ than in G+P- patients. LA contractile function did not differ between the groups (31% vs 32%, P = .87). Compared with patients with G+P- HCM, those with P+HCM had lower four-chamber LASr (29% vs 41%, P < .001), two-chamber LASr (30% vs 41%, P < .001), average LASr (29% vs 42%, P < .001), and LA contractile strain (9% vs 12%, P = .016). In the cohort of patients with HCM who underwent stress testing (n = 35), LA conduit function weakly correlated with aerobic capacity (r = 0.42, P = .019).

CONCLUSIONS

Children with P+HCM have reduced LA function, measurable by both volumetric and strain analysis. Altered LA mechanics are associated with poor exercise capacity. This study lays the foundation for the evaluation of novel LA parameters in pediatric HCM and warrants larger longitudinal studies to assess its clinical significance.

Left atrial dysfunction as marker of poor outcome in patients with hypertrophic cardiomyopathy

BACKGROUND

The incremental prognostic value of left atrial (LA) dysfunction, emerging in various clinical contexts, remains poorly explored in hypertrophic cardiomyopathy (HCM).

OBJECTIVE

To assess LA strain correlation with outcome in HCM.

METHODS

A cohort of all 307 consecutive patients presenting with HCM between 2007 and 2017 (54±17 years; 34% women), with comprehensive echocardiography at diagnosis and LA peak longitudinal strain (PALS) and LA peak contraction strain (PACS) measurement, was enrolled and occurrence of HCM related cardiac events analysed.

RESULTS

Clinically, atrial fibrillation (AF) was present in 13%, New York Heart Association functional class II-III in 54%, and B-type natriuretic peptide (BNP) concentration was 199±278pg/mL. By echocardiography, left ventricular (LV) ejection fraction (EF) was 67±10%, LV thickness 21±5mm and European Society of Cardiology HCM risk score 3±3%, with 109 patients (36%) presenting obstructive HCM (LV outflow gradient 21±32mmHg). LA diameter was 41±8mm [with 109 (36%) presenting LA diameter ≥40mm], LA volume index 50±26mL/m², PALS 24±13%, PACS 11±7% and LA peak systolic strain rate (LASRs) 1.7±0.6 s^-1. In addition to AF, age, BNP, LVEF and LV thickness were all independent determinants of lower PALS, with odd ratios almost unchanged after adjustment (all P ≤0.0004). At a mean follow-up of 21 (range 18-23) months, patients with adverse cardiac events (n=65) presented with more impaired LA function (all P ≤0.0005), with a significant association between impaired PALS and worse outcome, hazard ratio 0.94 [95% confidence interval (CI) 0.92-0.97, P<0.0001]. After comprehensive adjustment, PALS remained strongly associated with worse outcome, adjusted hazard ratio 0.86 (95% CI 0.79-0.94; P=0.0008).

CONCLUSIONS

The present study, by gathering a unique HCM cohort, suggests a strong link between LA dysfunction and poor outcome, to be further investigated.

Right atrial function assessed by volume-derived values and speckle tracking echocardiography in patients with hypertrophic cardiomyopathy

Background

To detect the right atrial (RA) functions in hypertrophic cardiomyopathy (HCM) patients by using volume-derived values and two-dimensional strain.

Methods

Thirty-two HCM patients and 34 age and gender matched normal controls were enrolled for this study. RA volume-derived values were measured by using 2D ultrasonic images. RA strain (S-reservoir, S-conduit, S-booster pump) and strain rate (SR-reservoir, SR-conduit, SR-booster pump), representing the reservoir, conduit and booster pump functions, respectively, were measured by EchoPAC.

Results

Total RA emptying fraction (RAEF) and RA expansion index in HCM patients were significantly lower than normal controls (p < 0.05). The values of S-reservoir, S-conduit, Sr-reservoir and Sr-conduit in HCM patients were significantly lower than normal controls (p < 0.001). Although there were no significant differences in S-booster pump and Sr-booster pump between HCM patients and normal controls, the absolute values in HCM patients were lower than normal controls.

Conclusions

In this study, we concluded that RA dysfunctions, including the reservoir and conduit functions were impaired in HCM patients.

Quantification of left atrial function in patients with non-obstructive hypertrophic cardiomyopathy by cardiovascular magnetic resonance feature tracking imaging: a feasibility and reproducibility study

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in hypertrophic cardiomyopathy (HCM) and is associated with adverse outcomes in HCM patients. Although the left atrial (LA) diameter has consistently been identified as a strong predictor of AF in HCM patients, the relationship between LA dysfunction and AF still remains unclear. The aim of this study is to evaluate the LA function in patients with non-obstructive HCM (NOHCM) utilizing cardiovascular magnetic resonance feature tracking (CMR-FT).

METHODS

Thirty-three patients with NOHCM and 28 healthy controls were studied. The global and regional LA function and left ventricular (LV) function were compared between the two groups. The following LA global functional parameters were quantitively analyzed: reservoir function (total ejection fraction [LA total EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive ejection fraction [LA passive EF], passive strain [εe], peak early-negative SR [SRe]), and booster pump function (active ejection fraction [LA active EF], active strain [εa], peak late-negative SR [SRa]). The LA wall was automatically divided into 6 segments: anterior, antero-roof, inferior, septal, septal-roof and lateral. Three LA strain parameters (εs, εe, εa) and their corresponding strain rate parameters (SRs, SRe, SRa) during the reservoir, conduit and booster pump LA phases were segmentally measured and analyzed.

RESULTS

The LA reservoir (LA total EF: 57.6 ± 8.2% vs. 63.9 ± 6.4%, p < 0.01; εs: 35.0 ± 12.0% vs. 41.5 ± 11.2%, p = 0.03; SRs: 1.3 ± 0.4 s- 1 vs. 1.5 ± 0.4 s- 1, p = 0.02) and conduit function (LA passive EF: 28.7 ± 9.1% vs. 37.1 ± 10.0%, p < 0.01; εe: 18.7 ± 7.9% vs. 25.9 ± 10.0%, p < 0.01; SRe: - 0.8 ± 0.3 s- 1 vs. -1.1 ± 0.4 s- 1, p < 0.01) were all impaired in patients with NOHCM when compared with healthy controls, while LA booster pump function was preserved. The LA segmental strain and strain rate analysis demonstrated that the εs, εe, SRe of inferior, SRs, SRe of septal-roof, and SRa of antero-roof walls (all p < 0.05) were all decreased in the NOHCM cohort. Correlations between LA functional parameters and LV conventional function and LA functional parameters and baseline parameters (age, body surface area and NYHA classification) were weak. The two strongest relations were between εs and LA total EF(r = 0.84, p < 0.01), εa and LA active EF (r = 0.83, p < 0.01).

CONCLUSIONS

Compared with healthy controls, patients with NOHCM have LA reservoir and conduit dysfunction, and regional LA deformation before LA enlargement. CMR-FT identifies LA dysfunction and deformation at an early stage.

Evaluation of Hypertrophic Cardiomyopathy: Newer Echo and MRI Approaches

PURPOSE OF REVIEW

This review discusses the basic and evolving echocardiographic and cardiac magnetic resonance (CMR) approaches in the diagnosis and management of patients with hypertrophic cardiomyopathy (HCM).

RECENT FINDINGS

Newer imaging technologies and techniques in both echocardiography and CMR have proved to add incremental value to our understanding of HCM. 3D reconstruction in echocardiography and CMR allows for more accurate morphological and volumetric assessment of the left ventricle. Echocardiographic and CMR-based left atrial assessment, including for its mechanical properties, has been shown to be correlated to outcomes and development of atrial fibrillation. Tissue characterization and scar burden quantification by late gadolinium enhancement on CMR has revolutionized our understanding of fibrotic processes in HCM and their contribution to disease severity and clinical outcomes. Cardiac imaging plays a crucial role in HCM patients. Using echocardiography and CMR as complementary modalities allows for improved diagnostics, optimization of treatment, and better prognostication.