Cardiac magnetic resonance imaging in the evaluation of patients with hypertrophic cardiomyopathy

A MYH7 variant in a five-generation-family with hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is a genetic condition with a prevalence of 1:500-1:3 000. Variants in genes encoding sarcomeric proteins are mainly responsible for the disease. MYH7 gene encoding a myosin heavy chain beta, together with MYPBC3 gene are the two most commonly affected genes. The clinical presentation of this disease varies widely between individuals. This study aims to report a variant of MYH7 responsible for HCM in a five-generation family with a history of cardiac problems. Methods: The diagnosis was established according to the European Society of Cardiology HCM criteria based on two-dimensional Doppler echocardiography or cardiovascular magnetic resonance. Genetic analysis was performed using next-generation-sequencing and Sanger method. Results: The medical history of the presented family began with a prenatal diagnosis of HCM in the first child of a family with previously healthy parents. Five generations of the family had a long history of sudden cardiac death and cardiac problems. A NM_000257.4:c.2342T>A (p.Leu781Gln) variant was detected in the MYH7 gene. It was heterozygous in the proband and in all affected individuals in a large family. The variant was present in 10 affected members of the family, and was absent in 7 members. The clinical course of the disease was severe in several members of the family: three family members died of sudden cardiac death, one patient required heart transplantation, three underwent septal myectomy, and three required implantable cardioverter defibrillator (ICD) implantation. Conclusion: Herein, we report a MYH7 variant responsible for HCM. Familial HCM is inherited primarily in autosomal dominant mode, which is in accordance with our study. However, the presented family showed a broad clinical spectrum of HCM. Out of 10 family members with positive genetic testing 8 had severe presentation of the disease and 2 had a mild phenotype. This suggests that the severity of the disease may depend on other factors, most likely genetic.

News in diagnostics and treament of cardiomyopathies

Cardiomyopathies are defined as myocardial disorders in which the heart muscle is structurally and functionaly abnormal in the absence of a disease sufficient to cause this abnormality such as coronary artery disease, hypertension, valvular or congenital heart disease. According to the phenotype expresion cardiomyopathies are divided into dilated, hypertrophic, restrictive, arrhytmogenic and unclassified cardiomyopathies (noncompaction and tako-tsubo cardiomyopathy). The same phenotypic expression may include etiologically different forms of the disease, and at the same time phenotypic expression may change in many cardiomyopathies in the course of illness. For each type of cardiomyopathy, we further distinguish the familial (genetic) form and the acquired form. The clinical manifestation of the disease includes symptoms of heart failure, with reduced, mildly reduced or preserved ejection fraction, symptoms resulting from a number of arrhythmias and extracardiac symptoms, but in some cases symptoms may not be presented for a relatively long time. The disease can lead to significant morbidity and mortality if not detected and treated early, especially in young people who are frequently affected. Significant developments in diagnostic and treatment methods have led to an improvement in the prognosis of patients with cardiomyopathies in recent years.

Heart Failure with Preserved Ejection Fraction in Children

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

"Circumnavigation": A Worthy Descriptor to Depict Torrential Mitral Regurgitation and a Reverence to Ferdinand Magellan

"Circumnavigation" is never used as a verb in cardiology. Hypertrophic obstructive cardiomyopathy is a complex entity that often involves the mitral valve leading to eccentric mitral regurgitation. Utilizing multimodality imaging, assessing the severity of mitral regurgitation, and phenotyping the type of myocardial hypertrophy are achievable with certainty. We describe a case of a 42-year-old male who presented with palpitations and was ultimately diagnosed with hypertrophic obstructive cardiomyopathy with a mitral regurgitation. The torrential mitral regurgitation jet was so severe that it was "circumnavigating" the left atrium. In addition, we also draw historical parallelism with Magellan's heroic "circumnavigation" of the globe as we celebrate 500 years of his journey. Furthermore, we also describe the multimodality assessment of hypertrophic obstructive cardiomyopathy utilizing transthoracic echocardiography and cardiac magnetic resonance imaging. We discuss the challenges in quantifying such severe mitral regurgitation with any individual imaging modality.

Cardiovascular Magnetic Resonance Imaging Patterns in Rare Cardiovascular Diseases

Rare cardiovascular diseases (RCDs) have low incidence but major clinical impact. RCDs' classification includes Class I-systemic circulation, Class II-pulmonary circulation, Class III-cardiomyopathies, Class IV-congenital cardiovascular diseases (CVD), Class V-cardiac tumors and CVD in malignancy, Class VI-cardiac arrhythmogenic disorders, Class VII-CVD in pregnancy, Class VIII-unclassified rare CVD. Cardiovascular Magnetic Resonance (CMR) is useful in the diagnosis/management of RCDs, as it performs angiography, function, perfusion, and tissue characterization in the same examination. Edema expressed as a high signal in STIRT2 or increased T2 mapping is common in acute/active inflammatory states. Diffuse subendocardial fibrosis, expressed as diffuse late gadolinium enhancement (LGE), is characteristic of microvascular disease as in systemic sclerosis, small vessel vasculitis, cardiac amyloidosis, and metabolic disorders. Replacement fibrosis, expressed as LGE, in the inferolateral wall of the left ventricle (LV) is typical of neuromuscular disorders. Patchy LGE with concurrent edema is typical of myocarditis, irrespective of the cause. Cardiac hypertrophy is characteristic in hypertrophic cardiomyopathy (HCM), cardiac amyloidosis (CA) and Anderson-Fabry Disease (AFD), but LGE is located in the IVS, subendocardium and lateral wall in HCM, CA and AFD, respectively. Native T1 mapping is increased in HCM and CA and reduced in AFD. Magnetic resonance angiography provides information on aortopathies, such as Marfan, Turner syndrome and Takayasu vasculitis. LGE in the right ventricle is the typical finding of ARVC, but it may involve LV, leading to the diagnosis of arrhythmogenic cardiomyopathy. Tissue changes in RCDs may be detected only through parametric imaging indices.

Deep Neural Network for Cardiac Magnetic Resonance Image Segmentation

The analysis and interpretation of cardiac magnetic resonance (CMR) images are often time-consuming. The automated segmentation of cardiac structures can reduce the time required for image analysis. Spatial similarities between different CMR image types were leveraged to jointly segment multiple sequences using a segmentation model termed a multi-image type UNet (MI-UNet). This model was developed from 72 exams (46% female, mean age 63 ± 11 years) performed on patients with hypertrophic cardiomyopathy. The MI-UNet for steady-state free precession (SSFP) images achieved a superior Dice similarity coefficient (DSC) of 0.92 ± 0.06 compared to 0.87 ± 0.08 for a single-image type UNet (p < 0.001). The MI-UNet for late gadolinium enhancement (LGE) images also had a superior DSC of 0.86 ± 0.11 compared to 0.78 ± 0.11 for a single-image type UNet (p = 0.001). The difference across image types was most evident for the left ventricular myocardium in SSFP images and for both the left ventricular cavity and the left ventricular myocardium in LGE images. For the right ventricle, there were no differences in DCS when comparing the MI-UNet with single-image type UNets. The joint segmentation of multiple image types increases segmentation accuracy for CMR images of the left ventricle compared to single-image models. In clinical practice, the MI-UNet model may expedite the analysis and interpretation of CMR images of multiple types.

Early diagnosis of cardiomyopathies by cardiac magnetic resonance. Overview of the main criteria

Cardiomyopathies (CMPs) are diseases of the heart muscle. They include a variety of myocardial disorders that manifest with various structural and functional phenotypes and are frequently genetic. Myocardial disease caused by known cardiovascular causes (such as hypertension, ischemic heart disease, or valvular disease) should be distinguished from CMPs for classification and management purposes. Identification of various CMP phenotypes relies primarily upon echocardiographic evaluation. In selected cases, cardiac magnetic resonance imaging (CMR) or computed tomography may be useful to identify and localize fatty infiltration, inflammation, scar/fibrosis, focal hypertrophy, and better visualize the left ventricular apex and right ventricle.  CMR imaging has emerged as a comprehensive tool for the diagnosis and follow-up of patients with CMPs. The accuracy and reproducibility in evaluating cardiac structures, the unique ability of non-invasive tissue characterization and the lack of ionizing radiation, make CMR very attractive as a potential "all-in-one technique". Indeed, it provides valuable data to confirm or establish the diagnosis, screen subclinical cases, identify aetiology, establish the prognosis. Additionally, it provides information for setting a risk stratification (based on evaluation of proved independent prognostic factors as ejection fraction, end-systolic-volume, myocardial fibrosis) and follow-up. Last, it helps to monitor the response to the therapy. In this review, the pivotal role of CMR in the comprehensive evaluation of patients with CMP is discussed, highlighting the key features guiding differential diagnosis and the assessment of prognosis.

The Role of Cardiovascular Magnetic Resonance Imaging in the Evaluation of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder, affecting 1 out of 500 adults globally. It is a widely heterogeneous disorder characterized by a range of phenotypic expressions, and is most often identified by non-invasive imaging that includes echocardiography and cardiovascular magnetic resonance imaging (CMR). Within the last two decades, cardiac magnetic resonance imaging (MRI) has emerged as the defining tool for the characterization and prognostication of cardiomyopathies. With a higher image quality, spatial resolution, and the identification of morphological variants of HCM, CMR has become the gold standard imaging modality in the assessment of HCM. Moreover, it has been crucial in its management, as well as adding prognostic information that clinical history nor other imaging modalities may not provide. This literature review addresses the role and current applications of CMR, its capacity in evaluating HCM, and its limitations.

Cardiac magnetic resonance in the assessment of hypertrophic cardiomyopathy phenotypes and stages - pictorial review

The aim of this paper is to present recent advances in hypertrophic cardiomyopathy (HCM) diagnosis and treatment based on a literature review. Special emphasis has been placed on the role of cardiac magnetic resonance imaging (CMR) for the assessment of morphological and functional consequences of different stages of HCM including prognostication. The text is illustrated with the images and data of the HCM patients diagnosed with CMR study in our hospital. CMR is an important tool, particularly relevant in novel risk factors and LV dysfunction groups. The HCM group with overt left ventricular dysfunction is underrecognized, often labelled by clinicians as dilated cardiomyopathy. Advanced diagnostic and management strategies effectively influence the natural history of HCM.

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.

Cardiovascular magnetic resonance imaging for structural heart disease

Cardiovascular magnetic resonance (CMR) has increasingly become a powerful imaging technique over the past few decades due to increasing knowledge about clinical applications, operator experience and technological advances, including the introduction of high field strength magnets, leading to improved signal-to-noise ratio. Its success is attributed to the free choice of imaging planes, the wide variety of imaging techniques, and the lack of harmful radiation. Developments in CMR have led to the accurate evaluation of cardiac structure, function and tissues characterisation, so this non-invasive technique has become a powerful tool for a broad range of cardiac pathologies. This review will provide an introduction of magnetic resonance imaging (MRI) physics, an overview of the current techniques and clinical application of CMR in structural heart disease, and illustrated examples of its use in clinical practice.

[Surgical treatment of patients with obstructive hypertrophic cardiomyopathy]

OBJECTIVE

To analyze in-hospital results of surgical treatment of patients with obstructive hypertrophic cardiomyopathy.

MATERIAL AND METHODS

There were 15 patients (8 women and 6 men) with obstructive hypertrophic cardiomyopathy and severe mitral insufficiency for the period from November 2017 to March 2019. Mean age of patients was 55.9±7.1 years. All patients had chronic heart failure NYHA class III and secondary coronary insufficiency.

RESULTS

Surgical correction of LVOT obstruction and mitral valve repair with elimination of systolic anterior motion were technically successful in all cases. There was no need for mitral valve replacement in all patients. Heart failure NYHA class I-II in early postoperative period was observed in all cases.

CONCLUSION

Careful preoperative planning with a comprehensive analysis of hemodynamic and anatomical features of LV and certain surgical experience are essential for adequate correction of LVOT obstruction without atrioventricular node injury and mitral valve repair.

Apical hypertrophic cardiomyopathy: diagnosis, medical and surgical treatment

Apical hypertrophic cardiomyopathy (AHCM) is a rare form of hypertrophic cardiomyopathy, occasionally resulting in severe complications. The paper covers the etiology and pathogenesis of AHCM, different imaging methods and characteristic appearance of the disease in each of them. Echocardiography and cardiovascular magnetic resonance imaging (CMR) are known to be the most valuable imaging methods. Moreover, this review presents medical and surgical treatment, as well as the clinical course and prognosis. Despite possible morbid events the overall cardiovascular mortality rate of AHCM patients is low, and the prognosis is relatively optimistic.