Detection of apical hypertrophic cardiomyopathy by cardiovascular magnetic resonance in patients with non-diagnostic echocardiography

The Role of MRI in Prognostic Stratification of Cardiomyopathies

PURPOSE OF THE REVIEW

The aim of this review was to discuss the role of cardiac magnetic resonance (CMR) for the prognostic stratification of cardiomyopathies, highlighting strengths and limitations.

RECENT FINDINGS

CMR is considered as a diagnostic pillar in the management of non-ischemic cardiomyopathies. Over the last years, attention has shifted from CMR's diagnostic capability towards prognostication in the various settings of cardiomyopathies. CMR is considered the gold standard imaging technique for the evaluation of ventricular volumes and systolic function as well as providing non-invasive virtual-histology by means of specific myocardial tissue characterization pulse sequences. CMR is an additive tool to risk stratifying patients and to identify those that require strict monitoring and more aggressive treatment.

Cardiovascular magnetic resonance clarifies arrhythmogenicity in asymptomatic young athletes with ventricular arrhythmias undergoing pre-participation evaluation

Pre-participation sports examination (PPE) is a frequent reason for consultation. However, the exact role of cardiovascular magnetic resonance (CMR) in PPE remains undefined. The additive value of CMR in adolescent athletes with ventricular rhythm disturbances (VRDs) was investigated. We prospectively recruited and evaluated with CMR 50 consecutive, asymptomatic young athletes referred to our tertiary center after identification of VRDs on electrocardiogram (ECG) with otherwise normal standard PPE and echocardiography, and 20 age- and sex-matched healthy volunteer athletes who underwent the same evaluations. The primary outcome was case-control status and the secondary outcome was the discrimination between athletes with VRDs with and without non-sustained ventricular tachycardia (VT). CMR identified arrhythmogenic substrates in all athletes with VRDs. The predominant condition was myocarditis and arrhythmogenic right ventricular cardiomyopathy in patients with and without VT, respectively. Based on penalized regression analysis, late gadolinium enhancement (LGE), early gadolinium enhancement (EGE), extracellular volume fraction (ECV), and T2-mapping, best distinguished between case-control status. The aforementioned indices predicted case-control status independent of age and sex: EGE [Odds ratio (95% confidence interval): 6.89 (2.19-21.62) per 0.5-unit, P<0.001], LGE (perfect prediction), ECV [1.66 (1.25-2.22), P<0.001] and T2 mapping [1.40 (1.13-1.72), P=0.002], among other independent CMR-derived predictors. Only indexed ventricular volumes independently discriminated between VRD patients with and without VT. In this study, asymptomatic young athletes with VRDs and normal PPE/echocardiography were optimally discriminated from healthy control athletes by CMR-derived indices, and CMR allowed for the identification of arrhythmogenic substrates in all cases.

Magnetic Resonance Imaging Assessment of Pre- and Post-Surgery Myocardial Changes in Hypertrophic Cardiomyopathy: Correlation with Echocardiography

Hypertrophic cardiomyopathy (HCM) is a common form of cardiomyopathy and a leading cause of sudden death in the young. Magnetic resonance imaging (MRI) is an established pre-operative tool for the evaluating of patients suspected with HCM for morphological assessment and identifying patients at risk of sudden death. Echocardiography and MRI are equally used in the post-treatment assessment of cardiac function and morphology. In this report, we present the comparative role of these two modalities in pre- and post-operative imaging assessment in our patients, treated surgically with the left ventricular myomectomy. Relative merits of MRI and echocardiography are presented and discussed.

Phenotypes of hypertrophic cardiomyopathy: genetics, clinics, and modular imaging

Hypertrophic cardiomyopathy (HCM) is the most common cardiovascular disease with genetic transmission, characterized by the hypertrophy of any segment of the left ventricle (LV), not totally explained by improper loading conditions, with LV systolic function preserved, increased, or reduced. The histopathological mechanism involved in HCM refers to the primary injury of the myocardium, as follows: disorganized array of myocytes, extracellular matrix modification, microvascular dysfunction, with subsequent appearance of myocardial fibrosis. Multiple sarcomere proteins mutations are responsible for HCM, but two of them are involved in 70% of the cases of HCM: β-myosin heavy chain (MYH7) and myosin-binding protein C (MYBPC3). The development of new genetic techniques involving genome editing is promising to discover a gene therapy for patients with HCM. Clinical presentation may differ from asymptomatic to sudden cardiac death (SCD), the last one targeting younger adults. In this case, the diagnosis and evaluation of SCD risk factors is extremely important. The common method of diagnosis is transthoracic echocardiography, but cardiac magnetic resonance (CMR) imaging represents "gold standard" in the evaluation of HCM patients. Treatment includes pharmacological therapy, surgery, alcohol ablation, and not least SCD prevention.

Cardiac Imaging in the Athlete: Shrinking the "Gray Zone"

PURPOSE OF THE REVIEW

This review will explore frequently encountered diagnostic challenges and summarize the role cardiac imaging plays in defining the boundaries of what constitutes the athlete's heart syndrome versus pathology.

RECENT FINDINGS

Investigations have predominantly focused on differentiating the athlete's heart from potentially lethal pathological conditions that may produce a similar cardiac morphology. Guidelines have identified criteria for identifying definitive pathology, but difficulty arises when individuals fall in the gray zone of expected athletic remodeling and pathology. Transthoracic echo has traditionally been the imaging modality of choice utilizing parameters such as wall thickness, wall:volume ratio, and certain diastolic parameters. Newer echocardiogram techniques such as strain imaging and speckle tracking have potential additive utility but still need further investigation. Cardiac magnetic resonance (CMR) imaging has emerged as an additive technique to help differentiate the phenotypic overlap between these groups. Utilizing gadolinium enhancement and T1 mapping along with its excellent spatial resolution can help distinguish pathology from physiology. Both established and novel cardiac imaging modalities have been used for uncovering the at risk athletes with cardiomyopathies. The issue is of practical importance because athletes are frequently referred to the cardiologist with symptoms of fatigue, palpitations, presyncope, and/or syncope concerned about the safety of their future participation. Imaging is a key component of risk stratification and identifying normal findings of the developed athlete and those "at-risk" athletes.

Comprehensive Assessment of Endomyocardial Fibrosis with Cardiac MRI: Morphology, Function, and Tissue Characterization

Endomyocardial fibrosis (EMF) affects approximately 12 million persons worldwide and is an important cause of restrictive cardiomyopathy in the developing world, with the highest prevalence reported in sub-Saharan Africa, South Asia, and South America. EMF is characterized by apical filling with fibrotic tissue of one or both ventricles, often associated with thrombus, calcification, and atrioventricular valve regurgitation, leading to typical symptoms of restrictive heart failure. Transthoracic echocardiography (TTE) is the first-line modality for assessment of EMF, basically owing to its widespread availability. However, in recent years cardiac MRI has emerged as a powerful tool for assessment of cardiac morphology and function, with higher accuracy than TTE, along with the unique advantage of being able to provide comprehensive noninvasive tissue characterization. Delayed enhancement (DE) imaging is the cornerstone of cardiac MRI tissue characterization and allows accurate identification of myocardial fibrosis, conveying valuable additional diagnostic and prognostic information. The typical DE pattern in EMF, described as the "double V" sign, consists of a three-layered pattern of normal myocardium, thickened enhanced endomyocardium, and overlying thrombus at the apex of the affected ventricle; it has excellent correlation with histopathologic findings and plays an important role in differentiating EMF from other cardiomyopathies. Conversely, fibrous tissue deposition quantified using DE imaging, when indexed to body surface area, has been shown to be a strong independent predictor of mortality. The aim of this review is to summarize state-of-the-art applications of cardiac MRI for diagnostic and prognostic assessment of patients with suspected or confirmed EMF. Online supplemental material is available for this article. ^©RSNA, 2020.

Apical variant hypertrophic cardiomyopathy "multimodality imaging evaluation"

Apical variant hypertrophic cardiomyopathy (AHCM) is characterized by asymmetric hypertrophy of the left ventricular (LV) apex. T wave inversions of variable degree, particularly in the left precordial leads, and left ventricular hypertrophy (LVH) are common EKG findings in AHCM. Echocardiography is typically the initial imaging modality used in the diagnosis and evaluation of AHCM. The diagnosis is made when the LV apex has apical wall thickness of ≥ 15 mm or a ratio of apical to basal LV wall thickness of ≥ 1.3 at end-diastole. The use of microbubble contrast agents with echocardiography is helpful for visualization of the apex. Cardiac magnetic resonance (CMR) has the advantage of a large field of view and the ability to perform tissue characterization. Late gadolinium enhancement (LGE) sequences are essential in the assessment of potential areas of myocardial scarring. Cardiac computed tomography (CCT) has the advantage of being able to evaluate coronary arteries in addition to assessing cardiac anatomy and function. A "Solar Polar" map pattern is the characteristic feature of AHCM on myocardial perfusion imaging (MPI) in cases not associated with apical aneurysm (APA). Recognition of typical perfusion patterns in AHCM patients is not only important in the diagnostic evaluation of this disease process, but also for avoiding unnecessary and costly tests. The purpose of this article is to review the imaging features of AHCM from different imaging modalities and assess the value added of each modality in the diagnosis of AHCM.

Hypertrophic cardiomyopathy: genetics and clinical perspectives

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and defined by unexplained isolated progressive myocardial hypertrophy, systolic and diastolic ventricular dysfunction, arrhythmias, sudden cardiac death and histopathologic changes, such as myocyte disarray and myocardial fibrosis. Mutations in genes encoding for proteins of the contractile apparatus of the cardiomyocyte, such as β-myosin heavy chain and myosin binding protein C, have been identified as cause of the disease. Disease is caused by altered biophysical properties of the cardiomyocyte, disturbed calcium handling, and abnormal cellular metabolism. Mutations in sarcomere genes can also activate other signaling pathways via transcriptional activation and can influence non-cardiac cells, such as fibroblasts. Additional environmental, genetic and epigenetic factors result in heterogeneous disease expression. The clinical course of the disease varies greatly with some patients presenting during childhood while others remain asymptomatic until late in life. Patients can present with either heart failure symptoms or the first symptom can be sudden death due to malignant ventricular arrhythmias. The morphological and pathological heterogeneity results in prognosis uncertainty and makes patient management challenging. Current standard therapeutic measures include the prevention of sudden death by prohibition of competitive sport participation and the implantation of cardioverter-defibrillators if indicated, as well as symptomatic heart failure therapies or cardiac transplantation. There exists no causal therapy for this monogenic autosomal-dominant inherited disorder, so that the focus of current management is on early identification of asymptomatic patients at risk through molecular diagnostic and clinical cascade screening of family members, optimal sudden death risk stratification, and timely initiation of preventative therapies to avoid disease progression to the irreversible adverse myocardial remodeling stage. Genetic diagnosis allowing identification of asymptomatic affected patients prior to clinical disease onset, new imaging technologies, and the establishment of international guidelines have optimized treatment and sudden death risk stratification lowering mortality dramatically within the last decade. However, a thorough understanding of underlying disease pathogenesis, regular clinical follow-up, family counseling, and preventative treatment is required to minimize morbidity and mortality of affected patients. This review summarizes current knowledge about molecular genetics and pathogenesis of HCM secondary to mutations in the sarcomere and provides an overview about current evidence and guidelines in clinical patient management. The overview will focus on clinical staging based on disease mechanism allowing timely initiation of preventative measures. An outlook about so far experimental treatments and potential for future therapies will be provided.

How to evaluate premature ventricular beats in the athlete: critical review and proposal of a diagnostic algorithm

Although premature ventricular beats (PVBs) in young people and athletes are usually benign, they may rarely mark underlying heart disease and risk of sudden cardiac death during sport. This review addresses the prevalence, clinical meaning and diagnostic/prognostic assessment of PVBs in the athlete. The article focuses on the characteristics of PVBs, such as the morphological pattern of the ectopic QRS and the response to exercise, which accurately stratify risk. We propose an algorithm to help the sport and exercise physician manage the athlete with PVBs. We also address (1) which athletes need more indepth investigation, including cardiac MRI to exclude an underlying pathological myocardial substrate, and (2) which athletes can remain eligible to competitive sports and who needs to be excluded.

Call a Spade a Spade: Missed Diagnosis of Apical Hypertrophic Cardiomyopathy

Apical hypertrophic cardiomyopathy is a variant of hypertrophic cardiomyopathy characterized by apical hypertrophy, deep T-wave inversions in precordial electrocardiogram (EKG) leads, and a ventriculogram shaped like the "Ace of Spades." Patients are often asymptomatic but sometimes present with atypical chest pain, angina, or atrial fibrillation. The deep T-wave inversions on EKG often mimic acute coronary syndrome. Coronary angiogram in these patients is unrevealing, but the characteristic left ventriculogram establishes this diagnosis. The deep T-wave inversions can appear suddenly or deepen over years, making the diagnosis difficult to establish early in the disease. Transthoracic echocardiogram may miss the hypertrophied apex, but echo contrast imaging or cardiac magnetic resonance imaging can reliably confirm the diagnosis and detect apical aneurysms. We present a case of apical hypertrophic cardiomyopathy which was not evident despite many admissions, EKGs, cardiac catheterizations and echocardiograms until the diagnosis was confirmed with left ventriculogram and cardiac magnetic resonance imaging 20 years after initial presentation.

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.

Defining genotype-phenotype relationships in patients with hypertrophic cardiomyopathy using cardiovascular magnetic resonance imaging

PURPOSE

HCM is the most common inherited cardiomyopathy. Historically, there has been poor correlation between genotype and phenotype. However, CMR has the potential to more accurately assess disease phenotype. We characterized phenotype with CMR in a cohort of patients with confirmed HCM and high prevalence of genetic testing.

METHODS

Patients with a diagnosis of HCM, who had undergone contrast-enhanced CMR were identified. Left ventricular mass index (LVMI) and volumes were measured from steady-state free precession sequences. Late gadolinium enhancement (LGE) was quantified using the full width, half maximum method. All patients were prospectively followed for the development of septal reduction therapy, arrhythmia or death.

RESULTS

We included 273 patients, mean age 51.2 ± 15.5, 62.9% male. Of those patients 202 (74.0%) underwent genetic testing with 90 pathogenic, likely pathogenic, or rare variants and 13 variants of uncertain significance identified. Median follow-up was 1138 days. Mean LVMI was 82.7 ± 30.6 and 145 patients had late gadolinium enhancement (LGE). Patients with beta-myosin heavy chain (MYH7) mutations had higher LV ejection fraction (68.8 vs 59.1, p<0.001) than those with cardiac myosin binding protein C (MYBPC3) mutations. Patients with MYBPC3 mutations were more likely to have LVEF < 55% (29.7% vs 4.9%, p = 0.005) or receive a defibrillator than those with MYH7 mutations (54.1% vs 26.8%, p = 0.020).

CONCLUSIONS

We found that patients with MYBPC3 mutations were more likely to have impaired ventricular function and may be more prone to arrhythmic events. Larger studies using CMR phenotyping may be capable of identifying additional characteristics associated with less frequent genetic causes of HCM.

Apical hypertrophic cardiomyopathy with preexcitation presenting as a myocardial infarction and ischemic stroke with a history of recurrent syncope: A case report

Contrast-enhanced echocardiography or cardiac magnetic resonance imaging is of value in the diagnosis of apical hypertrophic cardiomyopathy. Apical hypertrophic cardiomyopathy is rare in Caucasians, and gene negativity does not rule out the diagnosis. Risk stratification for sudden cardiac death and decisions about anticoagulation in cases with atrial fibrillation should be based on guidelines.

Development and validation of a new method to diagnose apical hypertrophic cardiomyopathy by gated single-photon emission computed tomography myocardial perfusion imaging

AIM

The aim of this study is to develop and validate a new method to diagnose apical hypertrophic cardiomyopathy (AHCM) by the integral quantitative analysis of myocardial perfusion and wall thickening from gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

PATIENTS AND METHODS

Twenty-two consecutive patients, who showed T wave inversion of at least 3 mm in precordial leads and sinus rhythm in ECG, were enrolled. All the patients underwent cardiac magnetic resonance (CMR), gated rest SPECT MPI and echocardiography. According to CMR diagnostic results, 13 patients were categorized as in the AHCM group and the remaining nine patients were categorized as in the non-AHCM group. Operators who were blinded to the CMR diagnosis independently performed the diagnosis by gated SPECT MPI. The regions of interest inside the apical hotspots on the perfusion polar map were drawn and the mean values of wall thickening in the drawn region of interests were calculated. Using MRI diagnosis as the gold standard, AHCM was diagnosed based on receiver operating characteristic analysis of the mean wall thickening in the apical perfusion hotspot. The area under curve, sensitivity, specificity, and accuracy of our method were 0.97, 100%, 89%, and 95%, respectively.

CONCLUSION

Our new method has high sensitivity, specificity, and accuracy against CMR diagnosis. It has great promise to become a clinical tool in the diagnosis of AHCM.

A 66-Year-Old Female with Apical Hypertrophic Cardiomyopathy Presenting with Hypertensive Crises and Type 2 Myocardial Infarction and a Normal Coronary Angiogram

A 66-year-old female presented to the emergency room with an episode of chest pain that lasted for a few minutes before resolving spontaneously. Electrocardiogram showed a left bundle branch block, left ventricular hypertrophy, and T wave inversions in the lateral leads. Initial cardiac troponin level was 0.15 ng/ml, with levels of 4 ng/ml and 9 ng/ml obtained 6 and 12 hours later, respectively. The peak blood pressure recorded was 195/43 mmHg. Echocardiogram with DEFINITY showed a small left ventricular cavity with apical hypertrophy, and coronary angiogram showed no stenotic or occluding lesions in the coronary arteries. The patient was admitted for a type 2 myocardial infarction with hypertensive crises. She was diagnosed with having apical hypertrophic cardiomyopathy, which is a variant of hypertrophic cardiomyopathy (HCM) in which the hypertrophy predominantly involves the apex of the left ventricle resulting in midventricular obstruction, as opposed to the left ventricular outflow tract obstruction seen in HCM. Patients with apical HCM may present with angina, heart failure, myocardial infarction, syncope, or arrhythmias and are typically managed with medications like verapamil and beta-blockers for those who have symptoms and antiarrhythmic agents like amiodarone and procainamide for treatment of atrial fibrillation and ventricular arrhythmias. An implantable cardioverter defibrillator (ICD) is recommended for high-risk HCM patients with a history of previous cardiac arrest or sustained episodes of ventricular tachycardia, syncope, and a family history of sudden death.

Phenotypes of hypertrophic cardiomyopathy. An illustrative review of MRI findings

Objective

The purpose of this article is to review how cardiac MRI provides the clinician with detailed information about the hypertrophic cardiomyopathy (HCM) phenotypes, assessing its morphological and functional consequences.

Conclusion

An understanding of cardiac MRI manifestations of HCM phenotypes will aid early diagnosis recognition and its functional consequences.

Teaching Points

• The phenotypic variability of HCM expands beyond myocardial hypertrophy, to include morphological and functional manifestations, ranging from subtle anomalies to remodelling of the LV with progressive dilatation and thinning of its wall.

• The stages of HCM, which are based on the clinical evidence of disease progression, include subclinical HCM, the classic HCM phenothype, adverse remodelling and overt dysfunction, or end-stage HCM.

• Cardiac MRI provides the clinician with detailed information regarding the HCM phenotypes and enables the assessment of its functional consequences.

Cardiac Magnetic Resonance for Diagnosis and Risk Stratification

Cardiac MRI (CMR) is an essential tool for the evaluation of the patient with hypertrophic cardiomyopathy (HCM). First, the accurate morphologic imaging and measures that are possible with CMR help to ascertain the diagnosis. Second, the tissue characterization that can be done with MRI helps to define the abnormalities in the myocardium and to identify areas of fibrosis that have been linked to increase risk of sudden cardiac death and heart failure. In addition, CMR can help distinguish HCM from similar disease processes.

Ventricular Fibrillation Cardiac Arrest in African American Male with Apical Hypertrophic Cardiomyopathy

Apical hypertrophic cardiomyopathy (AHCM) is a rare form of non-obstructive hypertrophic cardiomyopathy. It is rarely reported in African American patients, and more commonly reported in Japanese patients. AHCM involves hypertrophy of the apex of the left ventricle. It is considered to have a benign prognosis in terms of cardiovascular mortality, however arrhythmias and sudden cardiac death have been reported. We report a case of a 49-year-old African American male with a history of hypertension, who presented to the emergency department after in field defibrillation for ventricular fibrillation cardiac arrest with return of spontaneous circulation after 10 minutes of cardiopulmonary resuscitation. Features of left ventricular hypertrophy and deep T-wave inversions in V3-V6 were noted on a 12-lead electrocardiogram which were suggestive of AHCM. Left heart catheterization with left ventriculography and coronary angiography confirmed the diagnosis of AHCM with the classic “ace of spades” sign. This case highlights the rare occurrence of AHCM with ventricular fibrillation cardiac arrest in an African American male, treated with hypertension management, aspirin, atorvastatin and automated implantable cardioverter-defibrillator placement.

Burden of ventricular arrhythmias at 12-lead 24-hour ambulatory ECG monitoring in middle-aged endurance athletes versus sedentary controls

Background

Whether prolonged and intense exercise increases the incidence of ventricular arrhythmias in middle-aged athletes remains to be established.

Design

Prospective, case-control.

Methods

We studied 134 healthy competitive athletes >30 years old (median age 45 (39–51) years, 83% males) who had been engaged in 9 ± 2 h per week of endurance sports activity (running, cycling, triathlon) for 13 ± 4 consecutive years. One hundred and thirty-four age- and gender-matched individuals served as controls. Both groups underwent 12-lead 24-h ambulatory electrocardiogram monitoring, which included a training session in athletes. Ventricular arrhythmias were evaluated in terms of number, complexity (i.e. couplet, triplet or non-sustained ventricular tachycardia), exercise-inducibility and morphology.

Results

Thirty-five (26%) athletes and 31 (23%) controls showed >10 isolated premature ventricular beats or ≥1 complex ventricular arrhythmia ( p = 0.53). Athletes with ventricular arrhythmias were older (median 48 versus 43 years old, p = 0.03) but did not differ with regard to hours of training and years of activity compared with athletes without ventricular arrhythmias. Ten (7%) athletes and six (5%) controls showed >500 premature ventricular beats/24 h ( p = 0.30): the most common ventricular arrhythmia morphologies were infundibular (six athletes and five controls) and fascicular (two athletes and one control).

Conclusions

The prevalence of ventricular arrhythmias at 24-hour ambulatory electrocardiogram monitoring did not differ between middle-aged athletes and sedentary controls and was unrelated to the amount and duration of exercise. These findings do not support the hypothesis that endurance sports activity increases the burden of ventricular arrhythmias. Among individuals with frequent premature ventricular beats, the predominant ectopic QRS morphologies were consistent with the idiopathic and benign nature of the arrhythmia.

Ventricular Arrhythmias in Young Competitive Athletes: Prevalence, Determinants, and Underlying Substrate

BACKGROUND

Whether ventricular arrhythmias (VAs) represent a feature of the adaptive changes of the athlete's heart remains elusive. We aimed to assess the prevalence, determinants, and underlying substrates of VAs in young competitive athletes.

METHOD AND RESULTS

We studied 288 competitive athletes (age range, 16-35 years; median age, 21 years) and 144 sedentary individuals matched for age and sex who underwent 12-lead 24-hour ambulatory electrocardiographic monitoring. VAs were evaluated in terms of number, complexity (ie, couplet, triplet, or nonsustained ventricular tachycardia), exercise inducibility, and morphologic features. Twenty-eight athletes (10%) and 13 sedentary individuals (11%) showed >10 isolated premature ventricular beats (PVBs) or ≥1 complex VA (P=0.81). Athletes with >10 isolated PVBs or ≥1 complex VA were older (median age, 26 versus 20 years; P=0.008) but did not differ with regard to type of sport, hours of training, and years of activity compared with the remaining athletes. All athletes with >10 isolated PVBs or ≥1 complex VA had a normal echocardiographic examination; 17 of them showing >500 isolated PVBs, exercise-induced PVBs, and/or complex VA underwent additional cardiac magnetic resonance, which demonstrated nonischemic left ventricular late gadolinium enhancement in 3 athletes with right bundle branch block PVBs morphologic features.

CONCLUSIONS

The prevalence of >10 isolated PVBs or ≥1 complex VA at 24-hour ambulatory electrocardiographic monitoring did not differ between young competitive athletes and sedentary individuals and was unrelated to type, intensity, and years of sports practice. An underlying myocardial substrate was uncommon and distinctively associated with right bundle branch block VA morphologic features.

Cardiac magnetic resonance imaging in heart failure: where the alphabet begins!

Cardiac Magnetic Resonance Imaging has become a cornerstone in the evaluation of heart failure. It provides a comprehensive evaluation by answering all the pertinent clinical questions across the full pathological spectrum of heart failure. Nowadays, CMR is considered the gold standard in evaluation of ventricular volumes, wall motion and systolic function. Through its unique ability of tissue characterization, it provides incremental diagnostic and prognostic information and thus has emerged as a comprehensive imaging modality in heart failure. This review outlines the role of main conventional CMR sequences in the evaluation of heart failure and their impact in the management and prognosis.

Imaging in Congenital and Hereditary Abnormalities of the Interventricular Septum: Clinical Anatomy and Diagnostic Clues

Early identification of congenital heart diseases, specifically those affecting the structural integrity and function of the interventricular septum, in childhood is important toward decreasing the morbidity and mortality of those affected. We review the pertinent clinical and imaging manifestations for those with ventricular septal defects, ventricular septal aneurysms, tetralogy of Fallot, and hypertrophic (obstructive) cardiomyopathy, in addition to discussing first-line imaging studies, including echocardiography, and indications for advanced imaging.

Cardiac MR Imaging of Hypertrophic Cardiomyopathy: Techniques, Findings, and Clinical Relevance

Hypertrophic cardiomyopathy (HCM) is a relatively common myocardial genetic disease having a wide variety of symptoms and prognoses. The most serious complications of HCM are sudden cardiac death induced by ventricular arrhythmia or inappropriate changes in blood pressure, and heart failure. Cardiac MR imaging is a valuable imaging method for detecting HCM because of its accurate measurement of wall thickness and myocardial mass without limited view and the unique ability of late gadolinium enhancement (LGE) to identify myocardial fibrosis related to the prognosis of HCM. Tagging and T₁ or T₂ mapping MR imaging techniques have emerged as quantitative methods for the evaluation of disease severity. In this review, we introduce the MR imaging techniques applied to HCM and demonstrate the typical phenotypes and some morphological characteristics of HCM. In addition, we discuss the clinical relevance of MR imaging for risk stratification and management of HCM.

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

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

Risk of Coronary Heart Events Based on Rose Angina Questionnaire and ECG Besides Diabetes and Other Metabolic Risk Factors: Results of a 10-Year Follow-up in Tehran Lipid and Glucose Study

BACKGROUND

High-risk individuals for CHD could be diagnosed by some non-invasive and low-priced techniques such as Minnesota ECG coding and rose angina questionnaire (RQ).

OBJECTIVES

The present study aimed at determining the risk of incident CHD according to ECG and RQ besides diabetes and other metabolic risk factors in our population.

METHODS

Participants comprised of 5431 individuals aged ≥ 30 years within the framework of Tehran lipid and glucose study. Based on their status on history of CHD, ECG, and RQ at baseline, all participants were classified to 5 following groups: (1) History^-Rose^-ECG^- (the reference group); (2) History^-Rose⁺ECG^-; (3) History^-Rose^-ECG⁺; (4) History^-Rose⁺ECG⁺; and (5) History⁺. We used Cox regression model to find the role of ECG and RQ on CHD, independent of other risk factors.

RESULTS

Overall, 562 CHD events were detected during the median of 10.3 years follow-up. CHD incidence rates were 55.9 and 9.09 cases per 1000 person-year for participants with and without history of CHD, respectively. Hazard ratios (HRs) (95% CIs) were 4.11 (3.27 - 5.11) for History + and 2.18 (1.63 - 2.90), 1.92 (1.47 - 2.51), and 2.48 (1.46 - 4.20) for History^-Rose⁺ECG^-, History^-Rose^-ECG⁺, and History^-Rose⁺ECG⁺, respectively. RQ and ECG had the same HRs as high as those for hypertension and hypercholesterolemia; however, diabetes showed statistically and clinically more effects on CVD than RQ and ECG.

CONCLUSIONS

RQ in general and, ECG especially in asymptomatic patients, were good predictors for CHD events in both Iranian males and females; however, their predictive powers were lower than that of diabetes.

Hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy is an inherited myocardial disease defined by cardiac hypertrophy (wall thickness ≥15 mm) that is not explained by abnormal loading conditions, and left ventricular obstruction greater than or equal to 30 mm Hg. Typical symptoms include dyspnoea, chest pain, palpitations, and syncope. The diagnosis is usually suspected on clinical examination and confirmed by imaging. Some patients are at increased risk of sudden cardiac death, heart failure, and atrial fibrillation. Patients with an increased risk of sudden cardiac death undergo cardioverter-defibrillator implantation; in patients with severe symptoms related to ventricular obstruction, septal reduction therapy (myectomy or alcohol septal ablation) is recommended. Life-long anticoagulation is indicated after the first episode of atrial fibrillation.

Yamaguchi syndrome presenting as atrioventricular nodal re-entrant tachycardia in an African-American patient

Apical hypertrophic cardiomyopathy (Yamaguchi syndrome) is a rare subtype of hypertrophic cardiomyopathy. The syndrome is more common in Japan where it was first described. Outside Asia, it is a very rare cause of hypertrophic cardiomyopathy. Apical hypertrophic cardiomyopathy is usually detected incidentally and has a good long-term outcome. We present a case of apical hypertrophic cardiomyopathy in an African-American patient manifesting as atrioventricular nodal re-entrant tachycardia.

Novel junctophilin-2 mutation A405S is associated with basal septal hypertrophy and diastolic dysfunction

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A JPH2 A405S mutation was found in a human HCM patient.

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A novel echocardiographic imaging plane revealed septal hypertrophy in a mouse model bearing the human JPH2 mutation, thereby causally linking it to HCM pathogenesis.

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This alpha helical JPH2 mutation resulted in decreased transverse tubule regularity and aberrant calcium handling in septal cardiomyocytes.

Junctophilin-2 (JPH2) is a structural calcium (Ca²⁺) handling protein, which approximates the cardiomyocyte transverse tubules (TTs) to the sarcoplasmic reticulum. This facilitates communication of the voltage-gated Ca²⁺ channel and the ryanodine receptor RyR2. A human patient with hypertrophic cardiomyopathy was positive for a JPH2 mutation substituting alanine-405—located within the alpha helix domain—with a serine (A405S). Using a novel mouse echocardiography plane, we found that mice bearing this JPH2 mutation developed increased subvalvular septal thickness. Cardiomyocytes from the septa of these mice displayed irregular TTs and abnormal Ca²⁺ handling including increased SERCA activity.

Hypertrophic Cardiomyopathy from A to Z: Genetics, Pathophysiology, Imaging, and Management

Hypertrophic cardiomyopathy (HCM) is a heterogeneous group of diseases related to sarcomere gene mutations exhibiting heterogeneous phenotypes with an autosomal dominant mendelian pattern of inheritance. The disorder is characterized by diverse phenotypic expressions and variable natural progression, which may range from dyspnea and/or syncope to sudden cardiac death. It is found across all racial groups and is associated with left ventricular hypertrophy in the absence of another systemic or cardiac disease. The management of HCM is based on a thorough understanding of the underlying morphology, pathophysiology, and clinical course. Imaging findings of HCM mirror the variable expressivity and penetrance heterogeneity, with the added advantage of diagnosis even in cases where a specific mutation may not yet be found. The diagnostic information obtained from imaging varies depending on the specific stage of HCM-phenotype manifestation, including the prehypertrophic, hypertrophic, and later stages of adverse remodeling into the burned-out phase of overt heart failure. However, subtle or obvious, these imaging findings become critical components in diagnosis, management, and follow-up of HCM patients. Although diagnosis of HCM traditionally relies on clinical assessment and transthoracic echocardiography, recent studies have demonstrated increased utility of multidetector computed tomography (CT) and particularly cardiac magnetic resonance (MR) imaging in diagnosis, phenotype differentiation, therapeutic planning, and prognostication. In this article, we provide an overview of the genetics, pathophysiology, and clinical manifestations of HCM, with the spectrum of imaging findings at MR imaging and CT and their contribution in diagnosis, risk stratification, and therapy.

The Role of Cardiac MRI in the Diagnosis and Risk Stratification of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM), the most common genetic cardiomyopathy, is a disease characterised by substantial heterogeneity. Although the majority of patients with HCM remain asymptomatic with near-normal longevity, a small, but important, subset remain at risk for a wide range of clinical outcomes including sudden death. Cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as an imaging modality particularly well suited to characterise the phenotypic expression of HCM. CMR helps in the diagnosis of HCM by identifying areas of hypertrophy not well visualised by echocardiography, providing more accurate wall thickness measurements and differentiating HCM from other causes of left ventricular (LV) hypertrophy. CMR has led to the identification of novel subgroups of patients with HCM, including those with LV apical aneurysms (a subgroup at increased risk for ventricular arrhythmias and thromboembolic stroke), as well as abnormalities that contribute to LV outflow obstruction. Additionally, contrast-enhanced CMR with late-gadolinium enhancement (LGE) has recognised patients with extensive LGE (≥15 % LV myocardium) as individuals who may be at increased risk of sudden death, independent of other high-risk features, with implications on management strategies including consideration for primary prevention implantable cardioverter defibrillator therapy. These observations justify an expanded role of CMR in the routine clinical assessment of patients with HCM.

Update on hypertrophic cardiomyopathy and a guide to the guidelines

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM.

Myocardial Dimensions in Children With Hypertrophic Cardiomyopathy: A Comparison Between Echocardiography and Cardiac Magnetic Resonance Imaging

BACKGROUND

The primary mode of imaging in hypertrophic cardiomyopathy (HCM) is transthoracic echocardiography (TTE). However, in adults inadequate acoustic windows lead to poor quantification of myocardial thickness compared with cardiac magnetic resonance (CMR) imaging. In comparison, children have better acoustic windows and TTE measurements of wall thickness might be more accurate. The aim of this study was to assess the performance of TTE compared with CMR for the assessment of myocardial thickness in children with HCM.

METHODS

Nineteen children (median age, 12.7 years; range, 8.4-18.4 years) with known HCM were studied using TTE and CMR imaging on the same day. The left ventricle was measured off-line using the standard 16-segment model.

RESULTS

With CMR imaging 304 (19 × 16) segments were analyzable whereas only 263 were analyzable using echocardiography. Wall thickness measurements according to TTE were greater than those according to CMR imaging in the basal anterolateral, midventricular anterior and anterolateral and apical inferior, lateral and septal segments and smaller for the midventricular inferior and inferoseptal segments. Reproducibility of CMR and TTE measurements was assessed using the intraclass correlation coefficient (ICC). CMR measurements showed excellent intrareader (ICC, 0.929-0.991) and moderate inter-reader (ICC range, 0.512-0.991) reproducibility. TTE measurements revealed moderate intrareader (ICC, 0.575-0.942) and poor inter-reader (ICC range, -1.02 to 0.939) reproducibility.

CONCLUSIONS

Echocardiography incompletely assesses circumferential myocardial thickness in a proportion of pediatric patients with HCM. Echocardiography under- and overestimates maximum wall thickness compared with CMR, depending on the location. Measurements using CMR are more reproducible than those obtained using echocardiography.

The mechanisms, diagnosis and management of mitral regurgitation in mitral valve prolapse and hypertrophic cardiomyopathy

Valvular disease is a frequent cardiac pathology leading to heart failure and, ultimately, death. Mitral regurgitation, defined as the inability of the two mitral leaflets to coapt, is a common valvular disease and a self sustained pathology. A better understanding of the mitral valve histological layers provides a better understanding of the leaflet and chordae changes in mitral valve prolapse. Mitral valve prolapse may occur in myxomatous degenerative abnormalities, connective tissue disorders or in sporadic isolated cases. It is the most common mitral abnormality of non-ischemic cause leading to severe surgery-requiring mitral regurgitation. In addition to standard echocardiographic investigations, newly implemented three-dimensional techniques are being used and they permit a better visualisation, from the so-called ‘surgical view’, and an improved evaluation of the mitral valve. Hypertrophic cardiomyopathy is the most frequent inherited myocardial disease caused by mutations in various genes encoding proteins of the cardiac sarcomere, leading to a marked left ventricular hypertrophy unexplained by other comorbidities. The pathological echocardiographic hallmarks of hypertrophic cardiomyopathy are left ventricular hypertrophy, left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve. The systolic anterior motion of the mitral valve contributes to the development of mitral regurgitation and further narrows the left ventricular outflow tract, leading to more severe symptomatology. Cardiac magnetic resonance imaging accurately measures the left ventricular mass, the degree of diastolic function and it may also be used to distinguish phenotypic variants. The clinical outcome of patients with these pathologies is mostly determined by the selected option of treatment. The purpose of surgical correction regarding mitral valve involvement is to restore valvular competence. Surgery has proven to be the only useful treatment in preventing heart failure, improving symptomatology and reducing mortality. Our approach wishes to enhance the understanding of the mitral valve’s involvement in hypertrophic cardiomyopathy and mitral valve prolapse from genetic, haemodynamic and clinical perspectives, as well as to present novelties in the grand field of treatment.