Different Types Of Cardiomyopathies Research Articles

MRI to assess arrhythmia and cardiomyopathies

Cardiovascular magnetic resonance (CMR) is highly precise for morphological and functional analyses of the myocardium, and has been used to assess different types of cardiomyopathies. Its ability to characterize tissue, especially with gadolinium (Gd) delayed-enhancement techniques, has shown promising results for the diagnosis of arrhythmogenic cardiomyopathies. In this review we discuss the background and potential of this approach, as well as its usefulness for assessing arrhythmias and cardiomyopathies.

Different Types of Cardiomyopathy Associated With Isolated Ventricular Noncompaction

Although mainly described in the context of dilated and hypokinetic left ventricles, it is unclear whether isolated ventricular noncompaction (IVNC) is a distinct cardiomyopathy, a subtype of dilated cardiomyopathy, or a morphogenetic disorder. To investigate the spectrum of cardiomyopathies associated with IVNC, children and adults with stringent echocardiographic diagnoses of IVNC were reviewed. Seventy-three patients (12 children aged <15 years) seen since 1994 satisfied stringent echocardiographic criteria for IVNC. Sixty-five patients (89%; 11 children) had dilated cardiomyopathy, 2 adults had clear-cut hypertrophic cardiomyopathy, 1 adult had restrictive cardiomyopathy (to the investigators' knowledge, the first reported example of this particular association), and 5 patients (1 child) had normal left ventricular morphology and function. In conclusion, knowledge that IVNC can co-exist with restrictive and hypertrophic cardiomyopathy (in addition to the dilated form) supports the concept that IVNC is a morphologic trait rather than a distinct cardiomyopathy. This knowledge should be taken into account during echocardiographic examination and encourage the use of contrast echocardiography (and magnetic resonance) and could also orient molecular biology studies.

Inherited Cardiomyopathies as a Troponin Disease

Troponin, one of the sarcomeric proteins, plays a central role in the Ca(2+) regulation of contraction in vertebrate skeletal and cardiac muscles. It consists of three subunits with distinct structure and function, troponin T, troponin I, and troponin C, and their accurate and complex intermolecular interaction in response to the rapid rise and fall of Ca(2+) in cardiomyocytes plays a key role in maintaining the normal cardiac pump function. More than 200 mutations in the cardiac sarcomeric proteins, including myosin heavy and light chains, actin, troponin, tropomyosin, myosin-binding protein-C, and titin/connectin, have been found to cause various types of cardiomyopathy in human since 1990, and more than 60 mutations in human cardiac troponin subunits have been identified in dilated, hypertrophic, and restrictive forms of cardiomyopathy. In this review, we have focused on the mutations in the genes for human cardiac troponin subunits and discussed their functional consequences that might be involved in the primary mechanisms for the pathogenesis of these different types of cardiomyopathy.

Incidence and common presentations of different types of Cardiomyopathies in our set up

OBJECTIVES: To see the incidence, prevalence and common presentation of different types of cardiomyopathies in patient presenting with congestive heart failure (CHF). SETTING: This study was carried out at Cardiology Department of Liaquat University Hospital Hyderabad over a period of 9 months from August 2001 to April 2002. METHODOLOGY: This descriptive case series study included 200 patients who presented with congestive heart failure or angina. Detailed history of all patients was taken, systemic examination done. After appropriate investigations a diagnosis of all cases was made and patients were treated accordingly. All the parameters studied were noted and compiled later on. RESULTS: Dilated cardiomyopathy was seen in 140 cases, ischemic cardiomyopathy in 38 cases and hypertrophic cardiomyopathy in 22 cases. While no case of restrictive cardiomayopathy was seen in this study. CONCLUSION: Ischemic cases are more common in our society than western world because of inadequate awareness and lack of facilities in rural areas. It was also noted that males of older age group suffer more from congestive heart failure due to cardiomyopathy than females.

Magnetic resonance imaging in patients with cardiomyopathies: when and why.

Cardiac magnetic resonance imaging (MRI) is a noninvasive tool which is able to diagnose and differentiate cardiomyopathies in a single study. The assessment of essential information such as alterations of myocardial and ventricular geometry and function is possible with a high degree of accuracy and reproducibility, based on a small inter- and intraobserver variability. Thus, very small morphological and functional changes in different types of cardiomyopathy are detectable, thereby enabling the cardiologist to increase the safety of therapeutic decisions. Furthermore, MRI bears the potential to characterize tissue transformation in the different types of myocardial affections including ischemic, toxic, infiltrative or inflammatory forms.

Extracellular Matrix Regulation in the Development of Syrian Cardiomyopathic Bio 14.6 and Bio 53.58 Hamsters

The myocardium contains a collagen matrix composed primarily of collagen and fibronectin, which are major determinants of the myocardial architecture, structural integrity and mechanical properties. The present study was undertaken to determine the age-related changes of the accumulation and degradation of the collagen matrix in Syrian myopathic hamsters, of the Bio 14.6 and Bio 53.58 strains. Those hamsters were used as models for hypertrophic and dilated cardiomyopathy, respectively. The heart to body weight ratio in the Bio 14.6 strains was higher (P<0.05) than that in the age-matched F1b strains. In the Bio 53.58 strains, the heart to body weight ratio was higher at 8 and 42 weeks of age than that in the F1b strains. The collagen content increased from 22 weeks of age in both Bio hamsters compared with age-matched F1b hamsters (P<0.05). In both cardiomyopathic hamsters, the mRNA expressions for type I and type III collagen and fibronectin all increased with aging; however, the fibronectin expression in the Bio 14.6 strains increased more at 22 weeks of age than at 42 weeks of age. The left ventricular MMP-1, MMP-2 and MMP-9 activities in Bio 53.58 strains increased with aging. However, in the Bio 14.6 strains, although MMP-1 activities increased with aging, MMP-2 and MMP-9 activities decreased at 42 weeks of age in comparison to those at 22 weeks of age. Thus, the MMP activation differed between two cardiomyopathic models at the stage of heart failure, although the collagen synthesis was elevated in both models. In conclusion, it would seem that the relative balance between the synthesis and the removal of collagen may contribute to the changes in the left ventricular geometry in two different types of cardiomyopathy.

Oxidative Stress Status in the Transition of Hypertrophy to Heart Failure

In response to a variety of stressful conditions such as pressure overload, volume overload, myocardial infarction and different types of cardiomyopathies, the heart undergoes an adaptation process during which it grows in size, a phenomenon referred to as hypertrophy. During this compensatory phase, the heart is better able to meet the increased work demand. However, if left untreated for a prolonged period, it can advance into the decompensated hypertrophic or the failing stage. It is now clear that transition of heart hypertrophy to the failure stage involves a number of abnormalities which include ionic imbalances, impairment in energy production and utilization, altered calcium metabolism and defects in the contractile proteins. More recently, alterations in free radicals and “antioxidant reserve” have been identified in the hypertrophy as well as failing stages. Discussion in this review is focussed on the role of oxidative stress in both compensated and decompensated stages, in various animal models of heart failure. Some clinical data on oxidative stress in heart failure patients is also reviewed. It is suggested that an increase in oxidative stress may play a role in the pathogenesis of heart failure.

Cardiovascular changes in children with mucopolysaccharide storage diseases and related disorders--clinical and echocardiographic findings in 64 patients.

Cardiovascular abnormalities were evaluated in 64 children aged between 1 year 9 months and 25 years with mucopolysaccharidoses (MPS) and related disorders. A heart murmur was heard in 18 patients, but in only 6 was it characteristic for specific valvular lesions. Echocardiography was performed in 63 children. In one girl cardiac lesions were diagnosed on autopsy. In 46 patients (72%), valvular lesions and/or different types of cardiomyopathy were detected. There were no characteristic changes for different types of MPS. In the majority of children in whom dermatan sulphate accumulated, cardiac involvement was the most frequent (88%) and severe. The most common lesion, regardless of MPS type, was thickening of the mitral valve (66%), with regurgitation or stenosis in 28 (44%). Aortic valve thickening was detected in 17 patients (27%), asymmetric septal hypertrophy or hypertrophic cardiomyopathy in 18, congestive cardiomyopathy in 1 and endocardial thickening in 13 patients. Cardiac involvement was less frequent in children with Sanfilippo disease. Two or more echocardiographic examinations were performed in 23 patients. In 19 of them (83%) cardiac changes were more severe during the second examination. One 7-year-old boy with Hunter disease underwent successful mitral valve replacement. CONCLUSIONS; Cardiac involvement is present in most patients with MPS although there are few clinical signs and symptoms. The most common and severe changes are in Hurler, Hunter, Maroteaux-Lamy and I-cell disease, rarely in Sanfilippo disease. Mitral valve deformation is most frequent in all patients. The cardiac lesions are progressive.

β1-Adrenoceptor autoimmunity in cardiomyopathy

A growing body of studies have confirmed that autoantibodies against β 1-adrenoceptors are present in different types of cardiomyopathy. This suggests that they play a role in the pathophysiology of the disease. This article will review the data indicating the presence of anti- β 1-adrenoceptor autoantibodies in cardiomyopathy. It will focus upon their structural and functional properties which could explain their possible role in the induction and development of cardiomyopathic diseases.

Cardiomyopathies of infancy.

Cardiomyopathies in infancy constitute an ill-defined group of conditions. Recently, however, a number of specific disorders of metabolism and mitochondrial abnormalities have been described. Idiopathic or primary cardiomyopathies remain poorly defined. Endocardial fibroelastosis, the most prominent member in this group, probably represents a reaction of the endocardium to various insults. The different types of cardiomyopathy (CM) present a similar clinical picture and require the expertise of a group of specialists for proper diagnosis. Therapy is mostly supportive, as only a few cases of CM are amenable to specific treatment. Orthopic cardiac transplantation may become a therapeutic option in the future for infants unresponsive to current therapy.

Dynamic geometry of the left ventricle in hypertrophy studied by quantitative angiocardiography.

An automated videoangiocardiographic system has been developed and used for the study of dynamic internal left ventricular geometry, in 53 patients (12 normals, 20 patients with different degrees of left ventricular [LV] pressure-, and 8 with LV volume overload. 9 patients had different types of cardiomyopathy and 4 atypical or failing LV). From the measurements of ejection phase parameters of contraction, the degree of endsystolic and enddiastolic excentricity of the LV, the ejection fraction, and the circumferential fiber shortening or shortening velocities it has been shown that there are no signs of impaired left ventricular function in mild and moderate left ventricular hypertrophy due to pressure or volume overload.