Spiral Hypertrophic Cardiomyopathy as Detected by Cardiac Magnetic Resonance

Hypertrophic cardiomyopathy (HCM) is a genetically determined heart muscle disease; characterized by left ventricular hypertrophy. Spiral HCM is described as having a counterclockwise rotation pattern of hypertrophy along with variable degrees of fibrosis. A 34‐year‐old female presented with symptoms suggestive of heart failure. Echocardiography showed concentric left ventricular hypertrophy with normal contractility. Cardiac MRI showed asymmetric septal hypertrophy with mid‐cavity obliteration and a spiral pattern of variably increasing wall thickness. Late gadolinium enhancement demonstrated several areas of abnormal post‐gadolinium uptake. We report a case of spiral HCM. We should consider cardiovascular magnetic resonance as the reference standard for diagnosing HCM.     

Cardiac Amyloidosis Mimicking Hypertrophic Cardiomyopathy

ABSTRACT. Amyloid infiltration of the heart may frequently masquerade as other cardiac disorders. The extended use of echocardiography may contribute to an erroneuous diagnosis of hypertrophic cardiomyopathy, as both conditions show several features in common. This was the case with the patient reported below. A low QRS amplitude, an increased right ventricular wall thickness, thickened cardiac valves, and a pericardial effusion may, however, indicate amyloid infiltration. The diagnosis of systemic amyloidosis of immunocytic origin was subsequently established in our patient. A definitive diagnosis of amyloid heart disease requires endomyocardial biopsy, but it is suggested that typical noninvasive findings together with demonstration of amyloid in an organ other than the heart is sufficient for a reliable diagnosis. In addition, systemic manifestations may contribute to a correct diagnosis in generalized amyloidosis. Our patient had features consistent with the rare muscle pseudohypertrophy syndrome, which is associated with immunocytic amyloidosis.     

Differentiation of Cardiac Amyloidosis and Hypertrophic Cardiomyopathy

ABSTRACT. Eriksson P, Backman C, Eriksson A, Eriksson S, Karp K, Olofsson B-O (Departments of Internal Medicine, Geriatric Medicine, and Clinical Physiology, University Hospital, Umeå, and Institute of Forensic Medicine, University of Umeå, Umeå, Sweden). Differentiation of cardiac amyloidosis and hypertrophic cardiomyopathy. A comparison of familial amyloidosis with polyneuropathy and hypertrophic cardiomyopathy by electrocardiography and echocardiography. Acta Med Scand 1987; 221:39–46. The clinical and echocardiographic features of cardiac amyloidosis may closely resemble those of hypertrophic cardiomyopathy, and the disorders may thus be mixed up. The present study was undertaken in an attempt to identify features separating the two conditions by analysis of electro- and echocardiographic findings in patients with familial amyloid polyneuropathy and hypertrophic cardiomyopathy. Twenty-nine patients with familial amyloidosis and 22 with hypertrophic cardiomyopathy were studied. Particular attention was given to (1) the sum of the S wave in V₁ and R wave in V₅ or V₆, (2) the echocardiographic left ventricular mass and (3) cross-sectional area, the presence or absence of (4) asymmetrical septal thickening, (5) granular and sparkling myocardial appearance, (6) thickened heart valves, (7) systolic anterior motion of the mitral valve, and (8) pericardial effusion. A granular and sparkling appearance of the myocardium and thickened heart valves were found to be the best predictors of cardiac amyloidosis, while low QRS amplitudes in relation to echocardiographic left ventricular mass and a pericardial effusion seemed less important. The presence of systolic anterior movement of the mitral valve, a large left ventricular mass and a sum of S in V₁ and R in V₅ or V₆ >35 mm indicated hypertrophic cardiomyopathy. When the four strongest predictors (left ventricular mass, thickened heart valves, a granular sparkling myocardial appearance, and systolic anterior movement of the mitral valve) were used to reclassify the present patients, 28 of 29 amyloidosis patients and 21 of 22 patients with hypertrophic cardiomyopathy were correctly categorized. Noninvasive methods may thus be useful for detecting the myocardial infiltrative process, and cardiac amyloidosis may be confidently diagnosed by typical noninvasive findings together with histopathological documentation of amyloid in an organ other than the heart.     

Cardiac Sarcoid: A Chameleon Masquerading as Hypertrophic Cardiomyopathy and Dilated Cardiomyopathy in the Same Patient

Sarcoidosis is a multisystem, granulomatous disease of unknown etiology often seen in young adults, with cardiac involvement in more than one‐quarter of sarcoid patients. The clinical presentation of cardiac sarcoid depends upon the location and extent of myocardium involved. Although cardiac sarcoid may produce asymmetrical septal hypertrophy, it is most commonly considered in the differential diagnosis of dilated cardiomyopathy. The hypertrophic stage of cardiac sarcoid is rarely seen. We describe a case of cardiac sarcoid in a young patient wherein a distinctive appearance of the cardiac sarcoid spectrum from “hypertrophic” stage to thinned/scarred stage, masquerading as hypertrophic cardiomyopathy followed by dilated cardiomyopathy, is demonstrated.     

Echocardiography and Cardiac MRI in Mutation‐Negative Hypertrophic Cardiomyopathy in an Older Patient: A Case Defining the Need for ICD

We report the case of a 67‐year‐old man with hypertrophic cardiomyopathy who presented for a second opinion about implantable cardio‐defibrillator (ICD) placement after a witnessed syncopal episode. Despite his older age, being mutation‐negative, and having a maximal septal thickness of 2.2 cm on echocardiography, he demonstrated rapid progression of myocardial fibrosis on cardiac MRI, correlating to ventricular tachyarrhythmias and syncope. We review the role of echocardiography and cardiac MRI in optimizing medical care for such patients who may not otherwise meet criteria for an ICD placement or further interventions.     

高危肥厚型心肌病患者的治疗策略

肥厚型心肌病是以不能解释的左心室肥大为特征、具有常染色体显性遗传特性的心肌疾病。梗阻性肥厚型心肌病患者因左室流出道存在梗阻,故症状明显,且更易出现恶性心律失常或心脏性猝死等严重事件,且尚无理想的治疗措施,目前以药物治疗、室间隔心肌酒精消融术、外科手术为主。现就心率慢而不能耐受药物治疗、具有心脏性猝死家族史且伴有晕厥、恶性心律失常的高危肥厚型心肌病患者的治疗做一综述。     

Hypertrophic Cardiomyopathy as a Manifestation of Multiple Myeloma

Multiple myeloma （MM） is a malignancy of the plasma cell characterized by migration and localization to the bone marrow where cells then disseminate and facilitate the formation of bone lesions. It is associated with a constellation of disease manifestations, apart from osteolytic lesions, anemia and immuno-suppression due to loss of normal hematopoietic stem cell function, and cardiac amyloidosis due to monoclonal immunoglobulin secretion as well. Amyloid infiltration of the heart may frequently masquerade as hypertrophic cardiomyopathy （HCM）. HCM, of which underlying cause and pathogenesis are largely unknown, is characterized by left and/or right ventricular hypertrophy, with predominant involvement of the interventricular septum in the absence of other causes of hypertrophy, such as hypertension or valvular heart diseases. While excessive hypertrophy of the myocardium is most commonly associated with myocyte hypertrophy, infiltration with amyloid always needs to be considered. In this report we presented two cases of multiple myeloma that mimicked hypertrophic cardiomyopathy so closely that it required bone marrow or endomyocardial biopsy to establish the diagnosis.     

肥厚型心肌病猝死相关危险因素的研究进展

肥厚型心肌病是一种相对常见的心脏疾病,在普通人群的发病率为0.2%。其临床特征异质性大,但大部分患者的寿命不受影响。尽管如此,心脏性猝死仍然是一部分患者尤其是年轻患者的首发症状。因而,目前迫切需要寻找合理的危险分层方法,将肥厚型心肌病中心脏性猝死高风险的患者鉴别出来。现重点对肥厚型心肌病的相关危险因素做一总结。     

肥厚型心肌病病因学研究进展

肥厚型心肌病是以心室壁心肌的非对称性肥厚为特征的一种特发性心肌疾病,目前被认为是一种基因突变所导致的常染色体疾病。在人类,在编码与构成肌小节有关的蛋白质的基因中,现在发现至少有11种基因,超过200种不同的基因突变类型与肥厚型心肌病有关。另外,一些与肌小节无关的基因突变也参与了该病的发生。     

Molecular Genetic Basis of Hypertrophic Cardiomyopathy:

Genetics of SCD in HCM. Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease caused by mutations in sarcomeric proteins. The disease is characterized by left ventricular hypertrophy in the absence of an increased external load, and myofibrillar disarray. A large number of mutations in genes coding for the β-myosin heavy chain (β-MyHC), cardiac troponin T (cTnT), cardiac troponin I, α-tropomyosin, myosin binding protein C (MyBP-C), and myosin light chain 1 and 2 in patients with HCM have been identified. Genotype-phenotype correlation studies have shown that mutations carry prognostic significance. The Gly²⁵⁶Glu, Val⁶⁰⁶Met, and Leu⁹⁰⁸Val mutations in the μ-MyHC are associated with a benign prognosis. In contrast, Arg⁴⁰³Gln, Arg⁷¹⁹Trp, and Arg⁴⁵³Cys mutations are associated with a high incidence of sudden cardiac death (SCD). Mutations in cTnT are associated with a mild degree of hypertrophy, but a high incidence of SCD. Mutations in MyBP-C are associated with mild hypertrophy and a benign prognosis. However, it has become evident that factors other than the underlying mutations, such as genetic background and possibly environmental factors, also modulate phenotypic expression of HCM.     

Doppler Characteristics of Coronary Blood Flow in Infantile Hypertrophic Cardiomyopathy with Cardiac Tamponade

The co-existence of severe hypertrophic cardiomyopathy and massive pericardial effusion is a rare combination that may lead to a significant decrease in diastolic cardiac filling with marked hemodynamic compromise. We present a unique case where both conditions co-existed in an infant leading to marked diastolic cardiac dysfunction. It was possible to image the prominent epicardial coronary arteries and assess the coronary blood flow before and after pericardiocentesis using transthoracic two-dimensional Doppler echocardiography. With large pericardial effusion, there was a significant reduction in coronary blood flow during systole, which increased after pericardiocentesis. The exact mechanism for such phenomenon is only speculative.     

Loperamide Toxicity Revealing Apical Hypertrophic Cardiomyopathy

Loperamide, a μ-opioid receptor agonist, can cause cardiotoxicity by inhibiting the potassium ion channel and slowing cardiomyocyte repolarization. This, in turn, can lead to frequent early afterdepolarizations, the most common mechanism of drug-induced long QT syndrome and torsades de pointes. Apical hypertrophic cardiomyopathy (AHCM) is a nonobstructive hypertrophic cardiomyopathy rarely associated with malignant arrhythmias. We present a case of loperamide-induced malignant ventricular arrhythmia revealing underlying AHCM in a 25-year-old woman with a history of sudden cardiac arrest (SCA) and opioid use.It is important to evaluate for structural heart disease in all patients presenting with SCA, regardless of presumed etiology such as drug-induced cardiotoxicity, to prevent missed opportunities for adequate treatment. Furthermore, the diagnosis of AHCM in SCA warrants further genetic evaluation for variances with a predilection for malignant arrhythmias.     

Intraventricular Systolic Flow Mapping in Hypertrophic Cardiomyopathy

Ninety-two consecutive patients with hypertrophic cardiomyopathy were studied with pulsed and continuous-wave Doppler and color flow imaging to assess the intraventricular systolic flow profile from apex to base and compare it with that obtained in normals and in patients with aortic stenosis and systemic hypertension. Hypertrophic cardiomyopathy patients had higher intraventricular blood flow velocities (cm/sec) from apex to base compared with normals and aortic stenosis and systemic hypertension patients (apex: 41.5 ± 17.3 vs 24 ± 1.9,26.1 ± 2.9, and 26.4 ± 3.3; papillary muscles: 95.4 ± 66.5 vs 41.9 ± 4.9, 46.2 ± 3.4, and 46.4 ± 5.7; outflow tract: 249.3 ± 176.2 vs 66.9 ± 8.4, 64.1 ± 10.8, and 66 ± 9.5, respectively) (P < 0.001). Eighty-six (93%) hypertrophic cardiomyopathy patients showed an abnormal intraventricular systolic color flow pattern at one or more sites but none of the patients with aortic stenosis or systemic hypertension or normal controls. Of those, 65 (71%) showed one or more variant (mosaic) flow, all of whom had intraventricular gradients, while 75 showed abnormal aliased flow at a site other than the subaortic area. It is concluded that patients with hypertrophic cardiomyopathy often exhibit an abnormal spatial distribution of the intraventricular systolic flow velocity profile compared with normals and patients with secondary forms of ventricular hypertrophy that can readily be recognized with color flow imaging. This could improve the sometimes difficult separation of hypertrophic cardiomyopathy patients from secondary hypertrophy.     

ST Segment “Hump” during Exercise Testing and the Risk of Sudden Cardiac Death in Patients with Hypertrophic Cardiomyopathy

Background: The appearance of a discrete upward deflection of the ST segment termed “the ST hump sign” (STHS) during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise. Objective: We investigated the prevalence and clinical significance of this sign in a population of patients with hypertrophic cardiomyopathy. Methods: Eighty‐one patients with hypertrophic cardiomyopathy (HCM) who underwent cardiopulmonary exercise testing were followed in a retrospective cohort study for a mean period of 5.3 years. Results: The appearance of the STHS at the peak of exercise testing was observed in 42 patients (52%), particularly in the inferior and the lateral leads. Patients with the STHS had higher fractional shortening and maximum left ventricular wall thickness and exhibited more frequently outflow tract gradient >30 mmHg at rest. Furthermore, the presence of STHS was a strong independent predictor of the risk of sudden cardiac death (SCD), as the latter occurred in eight of the patients with this sign (8/42, 19%) and in none of the patients without it (0/39, 0%) (P < 0.001). Conclusion: The appearance of a “hump” at the ST segment during exercise testing appears to be a risk factor for SCD in patients with HCM. However, further studies are necessary to validate this finding in larger populations and to elucidate the mechanism of the appearance of the “hump.”     

Evolutionary Change Mimicking Apical Hypertrophic Cardiomyopathy in a Patient with Takotsubo Cardiomyopathy

In this report, we introduce a case of thickening of the involved left ventricular apical segment on echocardiography and deep T‐wave inversions in precordial leads on electrocardiography transiently seen in the course of recovery from biventricular takotsubo cardiomyopathy, mimicking apical hypertrophic cardiomyopathy. This result suggests that the echocardiographic finding of transient myocardial edema can be identified by cardiac magnetic resonance imaging in takotsubo cardiomyopathy. Additionally, it persisted a few weeks after full functional recovery. We believe that this case will contribute in part toward clarifying the pathophysiology of takotsubo cardiomyopathy.