Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Global longitudinal strain in pre-symptomatic patients with mutation for transthyretin amyloidosis

BACKGROUND

Hereditary transthyretin (ATTRv) amyloidosis is rare, autosomal dominant disease with a fatal outcome if left untreated. Early stages detection is crucial for intervention. We aimed identifying early indexes of cardiac involvement and their eventual correlation with neurological indexes, in pre-symptomatic subjects with TTR gene mutation.

METHODS

Sixteen TTR-mutation carriers (mean age 51 ± 9 years, 6 males, 7 with Val30Met and 9 with Phe64Leu mutation) without left ventricular hypertrophy were studied. Predicted Age of Disease Onset (PADO) and time to PADO (Time-to PADO = PADO-age at evaluation) were computed. Subjects underwent: cardiological and echocardiographic assessment including global longitudinal strain (GLS); tactile and thermal quantitative sensory testing (QST); Perugini score by bone scintigraphy.

RESULTS

Time to PADO was 30 ± 15 years. Nine subjects showed abnormal GLS (> -20%), unrelated to age, LVMi, MWT, E/e', NT-proBNP or Time-to PADO. QST findings were abnormal in most subjects. At a worse cold pain threshold corresponded a worse GLS (r = 0.786, p < 0.001). Perugini score was positive in 1 subject.

CONCLUSIONS

GLS and QST findings support an early involvement of heart and small nerve fibers even many years before PADO. Interestingly, cardiac impairment seems to parallel that of small, nerve fibers, at least in the earliest stage of disease.

Hypertrophic Cardiomyopathy with Special Focus on Mavacamten and Its Future in Cardiology

Hypertrophic cardiomyopathy (HCM) is a heterogeneous group of heart muscle disorders that affects millions, with an incidence from 1 in 500 to 1 in 200. Factors such as genetics, age, gender, comorbidities, and environmental factors may contribute to the course of this disease. Diagnosis of HCM has improved significantly in the past few decades from simple echocardiographic evaluations to a more complex, multimodal approach embracing advanced imaging, genetic, and biomarker studies. This review focuses on Mavacamten, a selective allosteric inhibitor of cardiac myosin, as a pharmacological treatment for HCM. Patients with HCM experience pathological actomyosin interactions, leading to impaired relaxation and increased energy expenditure. Mavacamten decreases available myosin heads, reducing actomyosin cross-bridges during systole and diastole. By reducing the number of bridges left ventricular outflow tract pressure is normalized and cardiac cavities are filled. This mechanism enhances patient performance and alleviates symptoms such as chest pain and dyspnea. The results suggest the potential for Mavacamten to transform the treatment of obstructive hypertrophic cardiomyopathy. Studies to date have shown significant improvement in exercise capacity, symptom relief, and a reduction in the need for invasive procedures such as septal myectomy. Further studies are needed to confirm the clinical results.

Long-term follow-up study on obstructive hypertrophic cardiomyopathy patients treated with disopyramide: evidences of a notable trend in symptom control within a real-world clinical setting

Background

In obstructive hypertrophic cardiomyopathy (HOCM), disopyramide is used in patients who remain symptomatic despite β-blockers or verapamil. However, effectiveness of disopyramide therapy has not been clearly established due to inconsistent definition of responders and the insufficient length of follow-ups reported in literature. To address these shortcomings, we have conducted a retrospective analysis from detailed databases with long follow-up, from two HCM Referral Centers.

Methods

62 symptomatic HOCM patients (43% women, age 52 ± 14 years) with left ventricular (LV) outflow tract gradient (LVOTG) ≥ 50 mmHg at rest or during provocation, were recruited from two Italian Centers. Disopyramide was added as second-line therapy in the patients in whom symptoms persisted despite classic pharmacologic treatment. Patients in NYHA class > II at baseline who reached NYHA class II or I, and patients in NYHA class II at baseline who reached NYHA class I or symptoms stabilization were defined as responders.

Results

At follow-up, (mean 4.4 years, IQR 1.1-6.6 years), 47 patients (76%) were responders, whereas 15 (24%) were no-responders. Responders showed larger LV diastolic volume index (LVEDVi) at baseline as compared to no-responders (61 ± 14 vs. 49 ± 16 ml, respectively, p = 0.018), and, at follow-up, reached lower LVOTG than no-responders (43 ± 32 vs. 66 ± 28 mmHg, respectively, p = 0.013), with a LVOTG <50 mmHg more represented in responders than in no-responders (75% vs. 25%, respectively; p = 0.004). No side effects requiring discontinuation of the therapy were recorded.

Conclusion

HOCM patients treated with disopyramide as second-line therapy in a quite long-follow-up showed a significant improvement of symptoms, which avoided SRT in up to 70% of them. Moreover, our data suggest that a larger LVEDVi at baseline identify the subgroup of patients who benefit the most from the therapy in terms of symptoms and reduction of LVOTG below 50 mmHg during treatment. We will discuss specific situations where disopyramide may be preferred over myosin inhibition to ensure that effective therapeutic options are fully considered and not prematurely dismissed.

How are the predictors of sudden death modified after septal myectomy surgery?

BACKGROUND

Hypertrophic cardiomyopathy is a condition associated with an increased risk of sudden death compared to the general population. Extended septal myectomy surgery has been suggested to impact the reduction of sudden death events according to various publications. The aim of this study was to assess changes in the prevalence of sudden death predictors in a population of patients undergoing extended septal myectomy surgery.

METHODS

Ninety-four consecutive patients underwent extended septal myectomy surgery due to symptomatic hypertrophic cardiomyopathy. Risk factors for sudden death, as defined by the American Heart Association and the European Society of Cardiology, were evaluated before and three months after surgery.

RESULTS

The mean age of the population was 57 ± 13 years. A significant reduction was observed in the maximum septal thickness from 21.3 to 14 mm (p<0.001), along with a decrease in the anteroposterior diameter of the left atrium from 51 to 47 mm (p=0.021). Resting intraventricular gradients decreased from 49.2 to 6.4 mmHg (p<0.001), and Valsalva-induced gradients decreased from 93.9 to 8.7 mmHg (p<0.001). Non-sustained ventricular tachycardia decreased from 6% to 2% (p<0.001), and atrial fibrillation decreased from 30% to 15% (p<0.001). Ischemic behavior during exercise stress echo decreased from 6% to 0%, and the European Society of Cardiology sudden death risk score reduced from 3.32 to 1.44 (p<0.001).

CONCLUSIONS

In this cohort of hypertrophic cardiomyopathy patients, extended septal myectomy surgery was associated with a reduction in the number and magnitude of sudden death predictors, potentially explaining the reduced mortality reported in the literature.

Fever Unveiling a Hidden Cardiac Condition: A Case of Pediatric Hypertrophic Obstructive Cardiomyopathy

This case report presents the clinical management of a 18-month-old female child who presented with fever, cough, and cold symptoms for eight days. Despite initial treatment with antipyretic syrup, the persistence of symptoms prompted further evaluation, revealing signs of hypertrophic obstructive cardiomyopathy (HOCM) on echocardiography. The patient was subsequently initiated on beta-blocker therapy and supportive care, leading to clinical improvement and eventual discharge. This case underscores the importance of considering cardiac etiologies in pediatric patients presenting with nonspecific symptoms. It highlights the role of timely diagnosis and multidisciplinary management in optimizing outcomes for affected individuals. Further research and awareness efforts are warranted to enhance diagnostic capabilities and refine treatment strategies for pediatric cardiac conditions like HOCM.

Hypertrophic Cardiomyopathy in Saudi Arabia: A Systematic Review of the Epidemiological, Clinical, and Imaging Features

BACKGROUND

A systematic review was performed to deliver a critical view of clinical and research practice on hypertrophic cardiomyopathy (HCM) in Saudi Arabia. Scopus, PubMed, and Google Scholar databases were searched for original articles reporting clinical and/or imaging findings among HCM patients in Saudi Arabia. Of 559 records identified, 3 studies and 1 abstract were included, involving 169 patients.

METHODS

The mean age ranged between 40and 56 years, up to 93.3% were males. A family history of HCM was reported in one study (5%), and sudden cardiac death was investigated in two studies (9% and 13%). Dyspnea was the most frequent symptom (60-68.7%) reported, followed by chest pain (12.5%-73.3%).

RESULTS

Regarding complications, atrial fibrillation was reported among 0-25% of the patients, mitral regurgitations among 13.3-50%, and ventricular tachycardia among 5-12.5%. Imaging parameters were inadequately documented and suggested a high prevalence of left atrial enlargement, SVI + RV5 > 35 mm, blocks, and asymmetric septal hypertrophy.

CONCLUSION

The ejection fraction was reported by two studies with a mean±SD of 68±13% and 77.2±8.07%. The researchers stress the paucity, low quality, and disparity in time of original studies about HCM in Saudi Arabia and recommend conducting national multicenter studies, with appropriate design, notably using screening-based recruitment methods.

Critical Evaluation of Current Hypotheses for the Pathogenesis of Hypertrophic Cardiomyopathy

Hereditary hypertrophic cardiomyopathy (HCM), due to mutations in sarcomere proteins, occurs in more than 1/500 individuals and is the leading cause of sudden cardiac death in young people. The clinical course exhibits appreciable variability. However, typically, heart morphology and function are normal at birth, with pathological remodeling developing over years to decades, leading to a phenotype characterized by asymmetric ventricular hypertrophy, scattered fibrosis and myofibrillar/cellular disarray with ultimate mechanical heart failure and/or severe arrhythmias. The identity of the primary mutation-induced changes in sarcomere function and how they trigger debilitating remodeling are poorly understood. Support for the importance of mutation-induced hypercontractility, e.g., increased calcium sensitivity and/or increased power output, has been strengthened in recent years. However, other ideas that mutation-induced hypocontractility or non-uniformities with contractile instabilities, instead, constitute primary triggers cannot yet be discarded. Here, we review evidence for and criticism against the mentioned hypotheses. In this process, we find support for previous ideas that inefficient energy usage and a blunted Frank-Starling mechanism have central roles in pathogenesis, although presumably representing effects secondary to the primary mutation-induced changes. While first trying to reconcile apparently diverging evidence for the different hypotheses in one unified model, we also identify key remaining questions and suggest how experimental systems that are built around isolated primarily expressed proteins could be useful.

Multimodality Imaging in Cardiomyopathies with Hypertrophic Phenotypes

Multimodality imaging is a comprehensive strategy to investigate left ventricular hypertrophy (LVH), providing morphologic, functional, and often clinical information to clinicians. Hypertrophic cardiomyopathy (HCM) is defined by an increased LV wall thickness not only explainable by abnormal loading conditions. In the context of HCM, multimodality imaging, by different imaging techniques, such as echocardiography, cardiac magnetic resonance, cardiac computer tomography, and cardiac nuclear imaging, provides essential information for diagnosis, sudden cardiac death stratification, and management. Furthermore, it is essential to uncover the specific cause of HCM, such as Fabry disease and cardiac amyloidosis, which can benefit of specific treatments. This review aims to elucidate the current role of multimodality imaging in adult patients with HCM.

Myocardial Strain and Association With Clinical Outcomes in Danon Disease: A Model for Monitoring Progression of Genetic Cardiomyopathies

Background

Myocardial strain can identify subclinical left ventricular dysfunction in various cardiac diseases, but its association with clinical outcomes in genetic cardiomyopathies remains unknown. Herein, we assessed myocardial strain in patients with Danon disease (DD), a rare X‐linked autophagic disorder that causes severe cardiac manifestations.

Methods and Results

Echocardiographic images were reviewed and used to calculate myocardial strain from a retrospective, international registry of patients with DD. Regression analyses were performed to evaluate for an association of global longitudinal strain (GLS) and ejection fraction with the composite outcome (death, ventricular assist device, heart transplantation, and implantable cardioverter defibrillator for secondary prevention). A total of 22 patients with DD (male 14 [63.6%], median age 16.5 years) had sufficient echocardiograms for analysis. Absolute GLS was reduced with a mean of 12.2% with an apical‐sparing pattern observed. Univariable regression for GLS and composite outcome showed an odds ratio of 1.32 (95% CI, 1.02–1.71) with P=0.03. For receiver operating characteristic analysis, the areas under the curve for GLS and ejection fraction were 0.810 (P=0.02) and 0.605 (P=0.44), respectively. An absolute GLS cutoff of 10.0% yielded a true positive rate of 85.7% and false positive rate of 13.3%.

Conclusions

In this cohort of patients with DD, GLS may be a useful assessment of myocardial function and may predict clinical outcomes. This study highlights the potential use of myocardial strain phenotyping to monitor disease progression and potentially to predict clinical outcomes in DD and other genetic cardiomyopathies.

Efficacy of echocardiography for differential diagnosis of left ventricular hypertrophy: special focus on speckle-tracking longitudinal strain

Left ventricular (LV) hypertrophy (LVH) is a frequent imaging finding in daily clinical practice, and its presence is associated with poor outcomes and ventricular arrhythmias. It is commonly detected in athletes, arterial hypertension, aortic stenosis, hypertrophic cardiomyopathy, cardiac amyloidosis, Fabry disease, or Friedreich’s ataxia. Echocardiography plays an important role in detecting LVH and underlying causes in current clinical practice. While echocardiography is essential for the quantification and early detection of LV structural findings for various cardiovascular diseases, it has been reported that speckle-tracking echocardiographic parameters are also useful for the detection of early LV structural abnormalities. In particular, global longitudinal strain (GLS) assessed by two-dimensional speckle-tracking echocardiography is reportedly a sensitive marker for early subtle abnormalities of LV myocardial performance, helpful for the prediction of outcomes for various cardiac diseases, and superior to conventional echocardiographic indices. GLS is determined as the averaged peak longitudinal strain of 18 LV segments from standard apical views and can be assessed as a polar plot. This polar plot longitudinal strain mapping offers an intuitive visual overview of the global and regional LV longitudinal myocardial function status of various cardiomyopathies with LVH. This mapping is clinically practicable and the plot patterns obtainable as the result of further development of this technique for clinical practice provide clues to the etiology of cardiomyopathies. This article reviews the efficacy of echocardiography for differential diagnosis of LVH, with a special focus on the utility of speckle-tracking longitudinal strain.

The Role of Cardiac Imaging in the Diagnosis and Management of Anderson-Fabry Disease

Anderson-Fabry disease (AFD) is a rare X-linked inherited metabolic disorder which results in a deficiency or absence of the enzyme α-galactosidase A, leading to the accumulation of glycosphingolipids in various cells and organs including the heart. Cardiac involvement is common and results in increased myocardial inflammation, left ventricular hypertrophy (LVH), and myocardial fibrosis. Echocardiography and cardiovascular magnetic resonance (CMR) offer distinctive and often complementary use to assist in the diagnosis and monitoring pharmacologic therapy in AFD, including detection of the AFD cardiac phenotype, differentiation from other forms of LVH, and patient selection for therapeutic intervention. Advanced cardiac imaging holds promise in subclinical detection of AFD-related abnormalities as well as disease staging and prognostication.

Cardiac left ventricular myocardial tissue density, evaluated by computed tomography and autopsy

BACKGROUND

Left ventricular mass (LVM) is an independent risk factor for the prediction of cardiac events. Its assessment is a clinically important diagnostic procedure in cardiology and may be performed by Computed Tomography (CT). The aim of this study was to assess the correlation between the cardiac left ventricular shell volume (LVShV) determined by postmortem Computed Tomography (PMCT) and the anatomic LVM obtained at autopsy and to calculate the myocardial tissue density.

METHODS

A total of 109 deceased individuals were examined with a 64-slice CT scanner and LVShV was determined. At autopsy, the left ventricle was dissected and weighted. The correlation between LVShV and the anatomic LVM was analysed. Asymmetric left ventricular (LV) hypertrophy was recorded. Inter-observer variability was evaluated, and a density value for myocardial tissue was calculated.

RESULTS

The mean age of the deceased was 55 ± 16 years, and 58% was men. We found 30 cases of asymmetric LV hypertrophy. A highly positive correlation existed between LVShV and anatomic LVM (r = 0.857; p < 0.0001), regardless of hypertrophy, asymmetric hypertrophy and gender. The mean difference in the inter-observer variability for LVShV assessment was - 4.4 ml (95% CI: -26.4; 17.6). A linear regression analysis was performed, resulting in a value of 1.265 g/ml for myocardial tissue density. Applying the hitherto used myocardial tissue density of 1.055 g/ml underestimated the anatomic LVM by 18.1% (p < 0.0001).

CONCLUSION

PMCT is a helpful tool for the assessment of LVM, and LVShV is highly correlated with LVM as assessed by subsequent autopsy. The correlation between the two was independent of gender, hypertrophy and LV asymmetric hypertrophy. We found a higher myocardial tissue density of 1.265 g/ml compared to previous studies. We show that PMCT combined with autopsy may contribute not only to anatomical but also clinical knowledge.

Electrocardiographic and echocardiographic evaluation of a large cohort of peri-pubertal soccer players during pre-participation screening

BACKGROUND

The early diagnosis of cardiac abnormalities in young athletes may be helpful not only to identify subjects potentially at risk of sudden cardiac death but also to prevent stress-related cardiac dysfunction and cardiovascular events during the life of these subjects. The aim of our study was to investigate the prevalence of cardiac abnormalities in a population of young male soccer players undergoing pre-participation screening through electrocardiogram and trans-thoracic echocardiography.

METHODS

All consecutive male football players undergoing pre-participation screening comprehensive of medical history, physical examination, 12-lead electrocardiogram and trans-thoracic echocardiography at the FMSI Sport Medicine Institute in Rome between January 2008-March 2009 were enrolled in the study.

RESULTS

Overall, 2261 consecutive young athletes aged 12.4 ± 2.6 years were evaluated. Training-unrelated electrocardiogram abnormalities were observed in 65 (2.9%) athletes. Abnormal trans-thoracic echocardiography was observed in 102 athletes (4.5%), including two cases of hypertrophic cardiomyopathy, eight of mild left ventricular hypertrophy, six of mild left ventricular dilation and 17 of bicuspid aortic valve. An abnormal electrocardiogram was associated with anomalous trans-thoracic echocardiography in 11/65 (16.9%) cases. All athletes requiring sport disqualification were identified by electrocardiogram. Notably, among 2216 athletes with a normal electrocardiogram, 91 had abnormal trans-thoracic echocardiography, including six cases of left ventricular dilation and six of ventricular hypertrophy.

CONCLUSIONS

In a wide population of peri-pubertal male athletes, evaluation of the electrocardiogram identified all cardiac diseases requiring sport disqualification. Trans-thoracic echocardiography alone allowed the identification of cardiac abnormalities potentially leading to cardiomyopathies or major cardiovascular events over time.

Cardiomyopathy in the pediatric patients

Pediatric cardiomyopathies are a group of myocardial diseases with complex taxonomies. Cardiomyopathy can occur in children at any age, and it is a common cause of heart failure and heart transplantation in children. The incidence of pediatric cardiomyopathy is increasing with time. They may be associated with variable comorbidities, which are most often arrhythmia, heart failure, and sudden death. Medical imaging technologies, including echocardiography, cardiac magnetic resonance, and nuclear cardiology, are helpful in reaching a diagnosis of cardiomyopathy. Nevertheless, endomyocardial biopsy is the final diagnostic method of diagnosis. Patients warrant surgical operations, such as palliative operations, bridging operations, ventricular septal maneuvers, and heart transplantation, if pharmaceutical therapies are ineffective. Individual therapeutic regimens due to pediatric characteristics, genetic factors, and pathogenesis may improve the effects of treatment and patients' survival.

E/e' ratio and left atrial area are predictors of atrial fibrillation in patients with hypertrophic cardiomyopathy

INTRODUCTION

Atrial fibrillation (AF) occurs in about 20%-25% of patients with hypertrophic cardiomyopathy and is associated with increased risk of cardioembolism and heart failure impacting on patients' morbidity and mortality. The aim of this study was to identify echocardiographic predictors of AF in a cohort of patients with hypertrophic cardiomyopathy (HCM).

METHODS

Patients were recruited from 2 centers: Buenos Aires Cardiovascular Institute and the Hospital Vall d'Hebron of Barcelona which were analyzed together. Retrospective study using electronic charts.

RESULTS

A total of 321 patients with HCM and no documented history of AF were included. Median follow-up was 3 years. Mean age was 54 ± 16 years. Obstructive HCM was present in 41% of the patients, and 94.2% had preserved systolic function. Thirty-eight patients developed AF during the follow-up period (11.8%). Univariate analysis showed that age, maximum myocardial thickness, atrial area, an E/e' ratio ≥ 17, and systolic pulmonary pressure estimated by echocardiography were associated with new-onset AF. Multivariate analysis showed that E/e' ≥ 17 ratio {HR 3.27 ([1.10-9.27] P = .033)} and atrial area {HR 1.06 ([1.01-1.13] P = .037)} remained predictors of AF.

CONCLUSIONS

An E/e' ratio ≥ 17, as an expression of left ventricular filling pressures with impact on the left atrium, and left atrial area ≥28 cm² are strong predictors of AF in patients with HCM.

EvaLuation Using Cardiac Insertable Devices And TelephonE in Hypertrophic Cardiomyopathy (ELUCIDATE HCM)-rationale and design: a prospective observational study on incidence of arrhythmias in Sweden

INTRODUCTION

Hypertrophic cardiomyopathy (HCM) is a heterogeneous disease associated with sudden cardiac death (SCD) mainly due to ventricular tachycardia (VT) or fibrillation even though life-threatening bradycardia occurs. Risk stratification takes several variables into consideration including non-sustained VT (NSVT). An implantable cardioverter defibrillator effectively prevents SCD.Atrial fibrillation (AF) is common among patients with HCM and warrants anticoagulation even without conventional risk factors according to European guidelines. Routinely, the evaluation of arrhythmias using a 48-hour ambulatory external monitor takes place every 6-24 months if patients do not report palpitations. The remaining time the potential burden arrhythmia is unknown. Therefore, the aim of the present study is to assess NSVT and AF incidence during 18 months by an insertable cardiac monitor (ICM).

METHODS

Adult patients, aged 18-65 years, with a validated diagnosis of HCM are eligible for the study. The study sample is planned to include 30 patients. A Confirm Rx is implanted at the level of the fourth rib on the left side subcutaneously after local anaesthesia. The application for monitoring is installed in the patients' smartphone and symptoms registered by the patient activation and VT detection programmed as 160 bpm during ≥8 intervals. An AF episode is recorded based on ≥2 min duration. Bradycardia is recorded at ≤40 bpm or pause ≥3.0 s. The patients are followed during 18 months before explant.

ETHICS AND DISSEMINATION

The study was approved by The Regional Ethical Committee in Umeå (protocol number 2017/13-31). The study protocol, including variables and prespecified research questions, the study was registered at Clinical Trial Registration NCT03259113. Each patient is informed about the study in both oral and written form by a physician and included after written consent.

Misclassification of hypertrophic cardiomyopathy: validation of diagnostic codes

PURPOSE

To validate diagnostic codes for hypertrophic cardiomyopathy (HCM), analyze misclassfications, and estimate the prevalence of HCM in an unselected Swedish regional cohort.

PATIENTS AND METHODS

Using the hospitals' electronic medical records (used for the Swedish National Patient Register), we identified 136 patients from 2006 to 2016 with the HCM-related codes 142.1 and 142.2 (International Classification of Diseases).

RESULTS

Of a total of 129 residents in the catchment area, 88 patients were correctly classified as HCM (positive predictive value 68.2%) and 41 patients (31.8%) were misclassified as HCM. Among the 88 HCM patients (52.2% males), 74 were alive and 14 were dead (15.9%). This yields an HCM prevalence of 74/183,337, that is, 4.0 diagnosed cases per 10,000 in the adult population aged ≥18 years. The underlying diagnoses of misclassified cases were mainly hypertension (31.7%) and aortic stenosis (22.0%). Other types of cardiomyopathies accounted for several cases of misclassification: dilated (nonischemic or ischemic), left ventricular noncompaction, and Takotsubo. Miscellaneous diagnoses were amyloidosis, pulmonary stenosis combined with ventricular septal defect, aortic insufficiency, athelete's heart, and atrioventricular conduction abnormality. The mean age was not significantly different between HCM and misclassified patients (65.8±15.8 vs 70.1±13.4 years; P=0.177). There were 47.8% females among HCM and 60.8% females among misclassified (P=0.118).

CONCLUSION

One-third of patients diagnosed as HCM are misclassified, so registry data should be interpreted with caution. A correct diagnosis is important for decision-making and implementation of optimal HCM care; efforts should be made to increase awareness of HCM and diagnostic competence throughout the health care system.

Ultrasonic Assessment of Myocardial Microstructure in Hypertrophic Cardiomyopathy Sarcomere Mutation Carriers With and Without Left Ventricular Hypertrophy

BACKGROUND

The noninvasive assessment of altered myocardium in patients with genetic mutations that are associated with hypertrophic cardiomyopathy (HCM) remains challenging. In this pilot study, we evaluated whether a novel echocardiography-based assessment of myocardial microstructure, the signal intensity coefficient (SIC), could detect tissue-level alterations in HCM sarcomere mutation carriers with and without left ventricular hypertrophy.

METHODS AND RESULTS

We studied 3 groups of genotyped individuals: sarcomere mutation carriers with left ventricular hypertrophy (clinical HCM; n=36), mutation carriers with normal left ventricular wall thickness (subclinical HCM; n=28), and healthy controls (n=10). We compared measurements of echocardiographic SIC with validated assessments of cardiac microstructural alteration, including cardiac magnetic resonance measures of interstitial fibrosis (extracellular volume fraction), as well as serum biomarkers (NTproBNP, hs-cTnI, and PICP). In age-, sex-, and familial relation-adjusted analyses, the SIC was quantitatively different across subjects with overt HCM, subclinical HCM, and healthy controls (P<0.001). Compared with controls, the SIC was 61% higher in overt HCM and 47% higher in subclinical HCM (P<0.001 for both). The SIC was significantly correlated with extracellular volume (r=0.72; P<0.01), with left ventricular mass and E' velocity (r=0.45, -0.60, respectively; P<0.01 for both), and with serum NTproBNP levels (r=0.36; P<0.001).

CONCLUSIONS

Our findings suggest that the SIC could serve as a noninvasive quantitative tool for assessing altered myocardial tissue characteristics in patients with genetic mutations associated with HCM. Further studies are needed to determine whether the SIC could be used to identify subclinical changes in patients at risk for HCM and to evaluate the effects of interventions.

Hypertrophic Cardiomyopathy and Left Ventricular Outflow Tract Obstruction: Expecting the Unexpected

Hypertrophic cardiomyopathy is an increasingly recognized clinical disease that carries perioperative risk. Patients may or may not carry a preoperative diagnosis, but provocable left ventricular outflow tract gradients place them at risk for hemodynamic compromise under surgical conditions. Early recognition of obstructive patterns and rapid management alterations in the face of instability are imperative for the treatment of these patients. This review focuses on the diagnostic criteria, risk factors, and management strategies for the perioperative hypertrophic cardiomyopathy patient. Finally, novel diagnostic modalities are discussed.

Longitudinal strain bull's eye plot patterns in patients with cardiomyopathy and concentric left ventricular hypertrophy

Despite substantial advances in the imaging techniques and pathophysiological understanding over the last decades, identification of the underlying causes of left ventricular hypertrophy by means of echocardiographic examination remains a challenge in current clinical practice. The longitudinal strain bull’s eye plot derived from 2D speckle tracking imaging offers an intuitive visual overview of the global and regional left ventricular myocardial function in a single diagram. The bull’s eye mapping is clinically feasible and the plot patterns could provide clues to the etiology of cardiomyopathies. The present review summarizes the longitudinal strain, bull’s eye plot features in patients with various cardiomyopathies and concentric left ventricular hypertrophy and the bull’s eye plot features might serve as one of the cardiac workup steps on evaluating patients with left ventricular hypertrophy.

M-Mode Ultrasound Applications for the Emergency Medicine Physician

BACKGROUND

M-mode or "motion" mode is a form of ultrasound imaging that is of high clinical utility in the emergency department. It can be used in a variety of situations to evaluate motion and timing, and can document tissue movement in a still image when the recording of a video clip is not feasible.

OBJECTIVES

In this article we describe several straightforward and easily performed applications for the emergency physician to incorporate M-mode into his or her practice, including the evaluation for: 1) pneumothorax, 2) left ventricular systolic function, 3) cardiac tamponade, and 4) hypertrophic cardiomyopathy.

DISCUSSION

The emergency physician and other point-of-care ultrasound providers can use this versatile function in the evaluation of patients for a number of critical cardiopulmonary diagnoses.

CONCLUSION

A great deal of important information may be obtained with M-mode imaging through views and measurements that are relatively easy to obtain.

High throughput phenotyping of left and right ventricular cardiomyopathy in calcineurin transgene mice

Consistent protocols for the assessment of diastolic and systolic cardiac function to assure the comparability of existing data on preclinical models are missing. Calcineurin transgene (CN) mice are a preclinical model for hypertrophic and failing hearts. We aimed at evaluating left and right ventricular structural and functional remodeling in CN hearts with an optimized phenotyping protocol. We developed a protocol using techniques and indices comparable to those from human diagnostics for comprehensive in vivo cardiac screening using high-frequency echocardiography, Doppler, electrocardiography and cardiac magnetic resonance (CMR) techniques. We measured left and right ventricular dimensions and function, pulmonary and mitral flow pattern and the hearts electrophysiology non-invasively in <1 h per mouse. We found severe biventricular dilation and a drastic decline in performance in accordance with a condition of heart failure (HF), diastolic dysfunction and defects in electrical conduction in 8-week-old calcineurin transgenic mice. Echocardiography of the left ventricle was performed with and without anesthesia. In all cases absolute values on echocardiography compared with CMR were smaller for LV dimension and wall thickness, resulting in higher fractional shorting and ejection fraction. The study protocol described here opens opportunities to assess the added value of combined echocardiography, Doppler, CMR and ECG recording techniques for the diagnosis of biventricular cardiac pathologies i.e. of HF and to study symptom occurrence and disease progression non-invasively in high-throughput. Phenotyping CN hearts revealed new symptom occurrence and allowed insights into the diverse phenotype of hypertrophic failing hearts.

Tricuspid annular motion velocity as a differentiation index of hypertrophic cardiomyopathy from hypertensive heart disease

BACKGROUND

Hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM) are the most frequently encountered entities presenting left ventricular hypertrophy in routine echocardiographic examination, and their differentiation is sometimes difficult. Abnormalities in right ventricular (RV) myocardium have been reported frequently in patients with HCM more than in those with HHD. We therefore hypothesized that tricuspid annular motion (TAM) velocity determined by pulsed tissue Doppler echocardiography can be used to detect RV dysfunction in HCM and discriminate these etiologies.

METHODS

TAM velocities were compared among clinically stable patients with 60 HCM and 60 HHD patients as well as 60 age-matched healthy controls. Peak systolic, early diastolic (TAM-e'), and atrial systolic velocities were measured. RV myocardial performance index was measured by tissue Doppler method. To more accurately differentiate HCM from HHD, electrocardiographic findings and brain natriuretic peptide levels, which can both be examined simply and noninvasively, were investigated in addition to echocardiography.

RESULTS

RV wall thickness of the HCM group was greater than the HHD group (p=0.092), while there was no significant difference in RV myocardial performance index between the HCM and HHD groups (p=0.606). TAM-e' was significantly lower in the HCM group than in HHD and control groups (p=0.001). To differentiate HCM from HHD, TAM-e' was a powerful predictor as per multivariate logistic regression analysis (hazard ratio, 0.665; p<0.001) of parameters other than those of left ventricular parameters, and the area under the receiver operating characteristic curve (AUC) was 0.686 and the best cut-off value was ≤8.0cm/s (62% sensitivity, 65% specificity). Multivariate logistic analysis revealed that electrocardiographic ST-T changes were the next most effective marker for differentiating HCM after TAM-e'. When TAM-e' and ST-T changes were combined, the AUC increased to 0.748.

CONCLUSIONS

TAM-e' is a potentially useful index to differentiate HCM from HHD.

Large scale pedigree analysis leads to evidence for founder effects of Hypertrophic Cardiomyopathy in Rhesus Macaques (Macaca mulatta)

Hypertrophic Cardiomyopathy (HCM) is the abnormal thickening of the ventricles and an increase in cardiac mass. Analyses of 108 rhesus macaque probands with pronounced HCM revealed a strong genetic predisposition to this disease. Macaques are ideal for investigating HCM because of their marked similarity to humans genetically, physiologically and anatomically.

Spirito-Maron echocardiographic score: a marker for morphological and physiological assessment of patients with hypertrophic cardiomyopathy

AIMS

The heterogeneous distribution of hypertrophy in hypertrophic cardiomyopathy (HCM) limits the echocardiographic conventional measurements accuracy in the evaluation of left ventricular hypertrophy (LVH). The aim of this study was to assess the correlation of the echocardiographic Spirito-Maron score (SMS) with left ventricle (LV) mass quantification by cardiac magnetic resonance (CMR) and with LV diastolic function.

METHODS AND RESULTS

Left ventricle diastolic function parameters, SMS, LV mass (American Society of Echocardiography formula), and maximal wall thickness (MWT) were evaluated by two-dimensional (2D) transthoracic echocardiography. The SMS was obtained by adding the MWT of 4 LV segments, at the mitral valve or papillary muscles short-axis views. Echocardiographic parameters of LVH, including SMS, were correlated with LV mass obtained by CMR and with E/e' ratio. We included 45 patients (60% male, mean age 48 ± 18 years), who underwent 2D echocardiography. Twenty-two of them performed a CMR study. A positive correlation was found between SMS and CMR LV mass (r = 0.80; P < 0.001), whereas MWT (r = 0.62; P = 0.002) and the 2D LV mass (r = 0.60; P = 0.011) presented a lower correlation with CMR LV mass. The SMS was significantly correlated with E/e' ratio (r = 0.60; P = 0.007), whereas a nonsignificant correlation was found with MWT (r = 0.41; P = 0.081) and 2D LV mass (r = 0.22; P = 0.400).

CONCLUSION

Spirito-Maron score presents a highly positive correlation with CMR LV mass and with diastolic dysfunction severity in HCM patients. SMS is a reliable quantitative LVH measurement method and seems to provide more comprehensive morphological and physiological information than 2D echocardiographic conventional parameters used to estimate LVH.

Changes in left atrial deformation in hypertrophic cardiomyopathy: Evaluation by vector velocity imaging

Abstract:Objectives: Hypertrophic cardiomyopathy (HCM) represents a generalized myopathic process affecting both ventricular and atrial myocardium. We assessed the global and regional left atrial (LA) function and its relation to left ventricular (LV) mechanics and clinical status in patients with HCM using Vector Velocity Imaging (VVI). Methods: VVI of the LA and LV was acquired from apical four- and two-chamber views of 108 HCM patients (age 40 ± 19years, 56.5% men) and 33 healthy subjects, all had normal LV systolic function. The LA subendocardium was traced to obtain atrial volumes, ejection fraction, velocities, and strain (ϵ)/strain rate (SR) measurements. Results: Left atrial reservoir (ϵ_sys,SR_sys) and conduit (early diastolic SR_e) function were significantly reduced in HCM compared to controls (P < .0001). Left atrial deformation directly correlated to LVϵ_sys, SR_sys and negatively correlated to age, NYHA class, left ventricular outflow tract (LVOT) gradient, left ventricular mass index (LVMI), LA volume index and severity of mitral regurge (P < 0.001). Receiver operating characterist was constructed to explore the cutoff value of LA deformation in differentiation of LA dysfunction; ϵ_sys < 40% was 75% sensitive, 50% specific, SR_sys < 1.7s^− 1 was 70% sensitive, 61% specific, SR_e> − 1.8s^− 1 was 81% sensitive and 30% specific, SR_a> − 1.5s^− 1 was 73% sensitive and 40% specific. By multivariate analysis global LVϵ_sys and LV septal thickness are independent predictors for LAϵ_sys, while end systolic diameter is the only independent predictor for SR_sys, P < .001. Conclusion: Left atrial reservoir and conduit function as measured by VVI were significantly impaired while contractile function was preserved among HCM patients. Left atrial deformation was greatly influenced by LV mechanics and correlated to severity of phenotype.

Circulating miR-29a, among other up-regulated microRNAs, is the only biomarker for both hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy

OBJECTIVES

The purpose of this paper was to determine whether microRNAs (miRNAs) involved in myocardial remodeling were differentially expressed in the blood of hypertrophic cardiomyopathy (HCM) patients, and whether circulating miRNAs correlated with the degree of left ventricular hypertrophy and fibrosis.

BACKGROUND

miRNAs-small, noncoding ribonucleic acids (RNAs) that regulate gene expression by inhibiting RNA translation-modulate cellular function. Myocardial miRNAs modulate processes such as cardiomyocyte (CM) hypertrophy, excitation-contraction coupling, and apoptosis; non-CM-specific miRNAs regulate myocardial vascularization and fibrosis. Recently, the possibility that circulating miRNAs may be biomarkers of cardiovascular disease has been raised.

METHODS

Forty-one HCM patients were characterized with conventional transthoracic echocardiography and cardiac magnetic resonance. Peripheral plasma levels of 21 miRNAs were assessed by quantitative real-time polymerase chain reaction and were compared with levels in a control group of 41 age- and sex-matched blood donors.

RESULTS

Twelve miRNAs (miR-27a, -199a-5p, -26a, -145, -133a, -143, -199a-3p, -126-3p, -29a, -155, -30a, and -21) were significantly increased in HCM plasma. However, only 3 miRNAs (miR-199a-5p, -27a, and -29a) correlated with hypertrophy; more importantly, only miR-29a correlated also with fibrosis.

CONCLUSIONS

Our data suggest that cardiac remodeling associated with HCM determines a significant release of miRNAs into the bloodstream: the circulating levels of both cardiac- and non-cardiac-specific miRNAs are significantly increased in the plasma of HCM patients. However, correlation with left ventricular hypertrophy parameters holds true for only a few miRNAs (i.e., miR-199a-5p, -27a, and -29a), whereas only miR-29a is significantly associated with both hypertrophy and fibrosis, identifying it as a potential biomarker for myocardial remodeling assessment in HCM.

Can an athlete have too much ticker? Hypertrophic cardiomyopathy in young athletes

Sudden cardiac death (SCD) is an uncommon but devastating potential consequence of participation in competitive sport. It is seen in adolescent and young adult athletes. The most common cause of this, hypertrophic cardiomyopathy (HCM), is a genetic disorder responsible for more than a third of cases and is manageable. Screening is undertaken for HCM, using differing strategies in Europe and North America. Screening and early diagnosis have reduced the mortality rate but has come at a significant economic cost. The evidence and relevant arguments for and against screening are presented together with management strategies as reflected by an illustrative case.

Noninvasive imaging modalities and sudden cardiac arrest in the young: can they help distinguish subjects with a potentially life-threatening abnormality from normals?

Sudden cardiac arrest (SCA) in the young is always tragic, but fortunately it is an unusual event. When it does occur, it usually happens in active individuals, often while they are participating in physical activity. Depending on the population's characteristics, the most common causes of sudden cardiac arrest in these subjects are hypertrophic cardiomyopathy, congenital coronary abnormalities, arrhythmia in the presence of a structurally normal heart (ion channelopathies or abnormal conduction pathways), aortic rupture, and arrhythmogenic right-ventricular cardiomyopathy. Two-dimensional echocardiography (2-DE) has been proposed as a screening tool that can potentially detect four of these five causes of SCA, and many groups now sponsor community-based 2-DE SCA-screening programs. "Basic" 2-DE screening may include assessment of ventricular volumes, mass, and function; left atrial size; and cardiac and thoracic vascular (including coronary) anatomy. "Advanced" echocardiographic techniques, such as tissue Doppler and strain imaging, can help in diagnosis when the history, electrocardiogram (ECG), and/or standard 2-DE screening suggest there may be an abnormality, e.g., to help differentiate those with "athlete's heart" from hypertrophic or dilated cardiomyopathy. Cardiac magnetic resonance imaging or cardiac computed tomography can be added to increase diagnostic sensitivity and specificity in select cases when an abnormality is suggested during SCA screening. Test availability, cost, and ethical issues related to who to screen, as well as the detection of those with potential disease but low risk, must be balanced when deciding what tests to perform to assess for increased SCA risk.

Hypertrophic cardiomyopathy: infants, children, and adolescents

Hypertrophic cardiomyopathy (HCM) is characterized by inappropriate left ventricular hypertrophy (LVH) in the setting of a nondilated left ventricle. HCM is often associated with asymmetric LVH, a family history of HCM, sarcomeric genetic mutations, and an increased risk of sudden cardiac death. There is a wide clinical variability in HCM presenting during childhood and a relative lack of data on the pediatric population. This review will cover HCM presenting in infancy, childhood, and adolescence.

A longitudinal study on BIO14.6 hamsters with dilated cardiomyopathy: micro-echocardiographic evaluation

Background

In recent years, several new technologies for small-animal imaging have been developed. In particular, the use of ultrasound in animal imaging has focused on the investigation of accessible biological structures such as the heart, of which it provides a morphological and functional assessment. The purpose of this study was to investigate the role of micro-ultrasonography (μ-US) in a longitudinal study on BIO14.6 cardiomyopathic hamsters treated with gene therapy.

Methods

Thirty hamsters were divided into three groups (n = 10): Group I, untreated BIO 14.6 hamsters; Group II, BIO 14.6 hamsters treated with gene therapy; Group III, untreated wild type (WT) hamsters. All hamsters underwent serial μ-US sessions and were sacrificed at predetermined time points.

Results

μ-US revealed: in Group I, progressive dilation of the left ventricle with a change in heart morphology from an elliptical to a more spherical shape, altered configuration of the mitral valve and subvalvular apparatus, and severe reduction in ejection fraction; in Group II, mild decrease in contractile function and ejection fraction; in Group III, normal cardiac chamber morphology and function. There was a negative correlation between the percentage of fibrosis observed at histology and the ejection fraction obtained on μ-echocardiography (Spearman r: -0.839; p < 0.001).

Conclusions

Although histological examination remains indispensable for a conclusive diagnosis, high-frequency μ-echocardiography, thanks to the high spatial and contrast resolution, can be considered sufficient for monitoring therapeutic efficacy and/or the progression of dilated cardiomyopathy, providing an alternative tool for repeatable and noninvasive evaluation.

Serum levels of high-sensitivity troponin T: a novel marker for cardiac remodeling in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by inappropriate hypertrophy, small-vessel coronary artery disease, myocyte disarray, and increased interstitial fibrosis. High-sensitivity troponin T (hs-TnT) could be a reliable indicator of myocardial remodeling, a proposed prognostic marker in HCM. Therefore we hypothesized that increased hs-TnT levels are related to different variables associated with myocardial remodeling, such as the presence of fibrosis assessed with cardiac magnetic resonance imaging (MRI).

METHODS AND RESULTS

We included 95 hemodynamically stable HCM patients, 72 male, aged 45.7 ± 14.2 years, and 45 healthy control subjects with similar age and gender. A complete history and clinical examination was performed, including 12-lead electrocardiogram (ECG), echocardiography, 24-hour ECG-Holter monitoring, symptom-limited treadmill exercise test, and late gadolinium enhancement in cardiac MRI. Risk factors for sudden death were evaluated. A blinded cardiac MRI was performed with late gadolinium enhancement study. Serum hs-TnT levels were assayed. A high proportion (42%) of hemodynamically stable patients studied showed increased levels of hs-TnT. The hs-TnT levels were raised in patients with severe dyspnea: New York Heart Association (NYHA) functional class ≥3 (P = .020), outflow obstruction (P = .013), systolic dysfunction (P = .037), abnormal blood pressure response (P = .036), and presence of gadolinium enhancement (P = .021). The hs-TnT levels correlated positively with the maximum left ventricular wall thickness (r = 0.47; P < .001), left atrial diameter (r = 0.36, P = .014), and outflow gradient (r = 0.28; P = .008).

CONCLUSIONS

A high proportion of hemodynamically stable patients show increased levels of hs-TnT. We observed that raised hs-TnT serum levels are associated with different conditions related to the severity of the disease.