[Genetics of dilated cardiomyopathies].
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Adult↗
Biomedical subjects
L Mestroni
Publications and source records attributed to L Mestroni.
Evidence from family studies for autoimmunity in dilated cardiomyopathy.
Organ-specific antibodies are found in patients with autoimmune disease and their symptom-free relatives many years before clinical onset. Organ-specific cardiac antibodies can be found in patients with dilated cardiomyopathy (DCM) and their relatives, which supports the idea that DCM is an autoimmune disease. We did non-invasive cardiological assessment and antibody screening in 342 symptom-free relatives (170 male, 172 female, mean [SD] age 31 [16] years). 177 relatives were from 33 families with more than 1 affected individual (familial DCM) and 165 relatives from 31 families with only 1 affected member (non-familial DCM). The frequency of cardiac antibodies was higher among relatives of DCM patients than in controls (20% vs 3.5%, p = 0.0001). In 37 (58%) of the families studied, cardiac antibodies were found in the proband and/or in at least 1 family member and were more common in familial than in non-familial DCM (24% vs 15%, p = 0.036). Antibody-positive relatives were younger (26 [15] vs 33 [17] years, p = 0.01) and had a larger mean echocardiographic left ventricular end-systolic dimension (35 [6] vs 32 [6], p = 0.01 mm) and reduced percentage fractional shortening compared with antibody-negative relatives (31 [6] vs 34 [6], p = 0.008). Presence of cardiac-specific autoantibodies in symptom-free DCM relatives provides evidence of autoimmunity in a subset of our patients (58%), including familial and non-familial forms of DCM. These antibodies are associated with mild left ventricular systolic dysfunction on echocardiography and may be early markers for relatives at risk of DCM.
Adult↗
Low frequency of detection by nested polymerase chain reaction of enterovirus ribonucleic acid in endomyocardial tissue of patients with idiopathic dilated cardiomyopathy.
OBJECTIVES: The purpose of this study was to determine the prevalence of enteroviral infection in the myocardium of patients with idiopathic dilated cardiomyopathy by using a highly sensitive and specific detection technique. BACKGROUND: Recent molecular studies have suggested that enteroviral persistence (in particular, coxsackieviruses type B) may underlie idiopathic myocarditis and dilated cardiomyopathy. METHODS: The method used to detect enterovirus-specific ribonucleic acids (RNAs) is based on reverse transcription and nested polymerase chain reaction amplification with four pairs of primers from the conserved 5' noncoding region of the enteroviral genome. Several members of the Enterovirus genus are detectable by this assay (coxsackieviruses B1 to B6; polioviruses 1 to 3; echoviruses 9, 19 and 31), with a sensitivity threshold close to the detection of a single molecule of viral RNA in 1 mg of tissue sample. Endomyocardial tissue samples from 84 subjects were analyzed (77 samples obtained from left endomyocardial biopsies, 7 from explanted hearts). The subjects comprised 63 study patients (53 with dilated cardiomyopathy, 3 with idiopathic myocarditis, 1 with right ventricular dysplasia, 1 with restrictive cardiomyopathy, 1 with eosinophilic myocarditis, 1 with primary ventricular fibrillation and 3 with myocarditis of known etiology) and 21 control subjects with other diseases. RESULTS: Positive signals were obtained only in samples from six study patients (four with dilated cardiomyopathy, one with right ventricular dysplasia and one with myocarditis). Samples from control subjects, uninfected rat myocardium and cultured cell lines yielded systematically negative results. Moreover, the nucleotide sequence analysis of the amplification products from patients with positive samples raised doubts about the true positivity of these samples. CONCLUSIONS: This study suggests that the persistence of enteroviral RNA in dilated cardiomyopathy is not a major cause of the disease and that a careful analysis of polymerase chain reaction amplification products is essential in any study in which this technique is pushed to high sensitivity thresholds.
Adult↗
Familial dilated cardiomyopathy.
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Adolescent↗
Absence of linkage between idiopathic dilated cardiomyopathy and candidate genes involved in the immune function in a large Italian pedigree.
Idiopathic dilated cardiomyopathy (IDC) is a heart disease of unknown aetiology characterised by impaired ventricular function usually associated with dilatation of the cardiac chambers. In order to test the hypothesis of an immunological cause for the disease at the genetic level, we performed linkage analysis between the putative disease locus and some of the potential candidate genes involved in the immune response or coding for the targets for autoantibodies in a large multigeneration family (63 members) from southern Italy with autosomal dominant transmission of the disease. Twenty-nine polymorphic markers on 18 different chromosomal locations were investigated, including markers linked to the genes coding for the HLA antigens, the immunoglobulin heavy and light chains, the receptors for the immunoglobulin Fc fragments, the subunits of the T cell receptor and the associated CD3, CD4, CD8, and CD45 antigens, interleukins 1, 3, 4, 5, 6, 9, and 11, the interleukin 1 and 2 receptors, and the genes coding for the beta 1 adrenoreceptor, the adenine nucleotide translocator-1, and the cardiac alpha and beta myosin heavy chains. No evidence for genetic linkage to IDC was found at any of these candidate loci. These results indicate that the still unidentified IDC gene maps outside several loci involved in the regulation of immune reactivity.
Adult↗
Parental origin of the X chromosome in a patient with a Robertsonian translocation and Turner's syndrome.
We report on a proband with both a Robertsonian translocation and Turner's syndrome. Study of the parental origin of the X chromosome performed by microsatellite analysis indicates paternal origin of the X chromosome (Xpat). The occurrence of chromosome aberrations as a consequence of interchromosomal interactions is discussed.
Adolescent↗
Idiopathic left ventricular aneurysm: a clinical and pathological study of a new entity in the spectrum of cardiomyopathies.
In a prospective study on 340 cases with primary myocardial disease, eight patients (six males, two females, mean age 36 years, range 24-47) with an idiopathic left ventricular aneurysm were observed. All patients had normal coronary arteries, no angina or history of myocardial infarction; all but one had no risk factors for ischaemic heart disease; all had normal right ventricles; one patient had a history of familial dilated cardiomyopathy, two of 'flu-like' syndrome at the time of first symptom and two of alcohol abuse. All patients had ventricular tachycardia (VT), five sustained (of right bundle branch block morphology in three, and of different morphologies in two), three non-sustained. Patients with sustained VT had inducible VT (resembling the clinical one) on electrophysiological study. Electrocardiogram (ECG) showed an infarction pattern in three cases. Aneurysms were of limited size (2.1 +/- 1/11 segments on echocardiography) and were located in the septum, apex or posterior wall. Left ventricular ejection fraction (LVEF) was reduced (< 0.50) in six patients and was not correlated with the aneurysm size. The duration of illness was inversely correlated with LVEF (P < 0.05). Endomyocardial biopsy showed evidence of diffuse pathological changes in all cases (cell hypertrophy, myofibrillar lysis, mitochondriosis). During follow-up (64 +/- 32 months), patients were successfully treated with anti-arrhythmic drugs: no patients required surgical treatment to control ventricular arrhythmia. Considering the clinical and pathological features of idiopathic left ventricular aneurysm, this primary myocardial disease could be classified as a novel peculiar form of cardiomyopathy.
Adult↗
Molecular genetics of dilated cardiomyopathy.
The recent advances in molecular biology and genetic engineering are producing relevant results in cardiology, in particular in the field of cardiomyopathies. Molecular genetics has been used for the detection of viral genomes persisting in myocardial tissue of patients with idiopathic dilated cardiomyopathy (IDC). Very recent data, based on highly sensitive and specific technologies, suggest, however, that enterovirus persistence is not a major cause of the disease. Another application of molecular genetics is the study of the familial form of IDC, using linkage analysis as a tool for the identification of the disease gene. According to this method, the X-linked form of familial IDC has been mapped within the dystrophin gene in a series of families, and preliminary reports suggest that the mutation (or mutations) concerns the muscle-promoter region. Linkage studies on the autosomal dominant form of IDC are in progress. A possible approach is the identification of linkage between the disease and an array of "candidate genes". Preliminary data have ruled out the involvement of a series of relevant candidates genes, among which the cardiac beta-myosin heavy chain gene. An alternative approach for linkage studies is to perform a random screening of the genome, in which a large number of anonymous markers are selected and tested. In conclusion, molecular genetics is starting to provide fundamental data about the pathogenetic mechanisms of IDC. The relevance of these findings is also crucial for clinical and therapeutic implications.
Cardiomyopathy, Dilated↗
Nested polymerase chain reaction for high-sensitivity detection of enteroviral RNA in biological samples.
A method based on nested polymerase chain reaction was developed for the detection of enteroviral genomes in biological samples. By taking advantage of the conserved 5' noncoding region of the enteroviral RNA, two sets of primers were utilized, enabling the detection either of a broad range of enteroviruses or of group B coxsackieviruses only. The sensitivity of the method is close to the detection of single molecules of viral RNA in as much as 1 mg of tissue sample. A preliminary study showed the usefulness of this technique for the analysis of endomyocardial biopsy samples from patients with idiopathic dilated cardiomyopathy and myocarditis.
Base Sequence↗
[The classification of cardiomyopathies: is a revision opportune?].
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Cardiomyopathies↗
Beta-adrenergic neuroeffector abnormalities in the failing human heart are produced by local rather than systemic mechanisms.
In order to investigate the general cause of beta-adrenergic receptor neuroeffector abnormalities in the failing human heart, we measured ventricular myocardial adrenergic receptors, adrenergic neurotransmitters, and beta-adrenergic receptor-effector responses in nonfailing and failing hearts taken from nonfailing organ donors, subjects with endstage biventricular failure due to idiopathic dilated cardiomyopathy (IDC), and subjects with primary pulmonary hypertension (PPH) who exhibited isolated right ventricular failure. Relative to nonfailing PPH left ventricles, failing PPH right ventricles exhibited (a) markedly decreased beta 1-adrenergic receptor density, (b) marked depletion of tissue norepinephrine and neuropeptide Y, (c) decreased adenylate cyclase stimulation in response to the beta agonists isoproterenol and zinterol, and (d) decreased adenylate cyclase stimulation in response to Gpp(NH)p and forskolin. These abnormalities were directionally similar to, but generally more pronounced than, corresponding findings in failing IDC right ventricles, whereas values for these parameters in nonfailing left ventricles of PPH subjects were similar to values in the nonfailing left ventricles of organ donors. Additionally, relative to paired nonfailing PPH left ventricles and nonfailing right ventricles from organ donors, failing right ventricles from PPH subjects exhibited decreased adenylate cyclase stimulation by MnCl2. These data indicate that: (a) Adrenergic neuroeffector abnormalities present in the failing human heart are due to local mechanisms; systemic processes do not produce beta-adrenergic neuroeffector abnormalities. (b) Pressure-overloaded failing right ventricles of PPH subjects exhibit decreased activity of the catalytic subunit of adenylate cyclase, an abnormality not previously described in the failing human heart.
Adenylyl Cyclases↗
[Beta blocking agents in the treatment of dilated cardiomyopathy: review of the literature and clinical experience with 67 patients].
BACKGROUND: Several reports suggest that chronic beta blockade, most often with the beta 1 selective agent metoprolol, may improve hemodynamic and clinical function in patients with idiopathic dilated cardiomyopathy. However, controlled trials are limited and some studies have not shown beneficial effects in short term trials. Mechanisms of effectiveness are still debated and probably concern the capacity to avoid toxic myocardial damage by catecholamines, to induce receptor up-regulation, to contribute to the control of arrhythmias, to improve diastolic relaxation and other mechanisms. METHODS: After a revision of the literature, a preliminary clinical experience with metoprolol in dilated cardiomyopathy diagnosed according to the WHO definition is reported. Sixty-seven patients symptomatic for congestive heart failure or with complex ventricular arrhythmias associated with severe left ventricular dysfunction were submitted to test dose with metoprolol 5 mg bid for 2-7 days. All patients were completely studied, including coronary angiography and endomyocardial biopsy to exclude ischemic heart disease and active myocarditis. Four pts (6%) did not tolerate the first test dosage of metoprolol and twenty-two patients were excluded from analysis because of inadequate follow-up or because they were enrolled in an international trial. Forty-one patients underwent long-term treatment with metoprolol at a final mean dosage of 150 mg a day (range 50-200 mg) and are presently analyzed. The dosage was gradually increased during the first seven weeks. RESULTS: After 6 +/- 2 months and 12 +/- 2 months, 34 patients were stable or ameliorated (Group 1) and experienced an overall significant improvement of functional class (all pts in class I-II NYHA), of left and right ventricular ejection fraction (from 28 +/- 8.8% to 35.8 +/- 13.7% to 33.2 +/- 12.3% and from 38.6 +/- 11.8% to 42.4 +/- 5.8% to 45.2 +/- 12.2% respectively), of clinical signs of congestive heart failure, of cardiothoracic index, of left ventricular diameters and of arrhythmic pattern. Furthermore, the rate of ventricular couplets > 20/24h and of non-sustained ventricular tachycardia changed respectively from 46% and 54% to 4% and 21% at 12 +/- 2 months. None in Group 1 died nor is any waiting for heart transplantation. Eleven patients (Group 2) did not tolerate the drug acutely (4 pts) or deteriorated during the first 6 +/- 2 months (7 pts) of the treatment. In this group a worsening or an insignificant variation of all clinical and instrumental parameters was observed. During follow-up four patients of this group underwent heart transplantation (one died shortly after the operation because of infective complications), one died while waiting, two are currently waiting for heart transplantation, and three are still in heart failure (class III NYHA). No cases of sudden death occurred in any group of patients (15 pts with follow-up > 12 mo). CONCLUSIONS: Our uncontrolled study seems to confirm the beneficial effect of betablockers in a subgroup of patients with idiopathic dilated cardiomyopathy. The characterization of responders to this therapy is still undefined and will constitute the aim of future analyses.
Adolescent↗
[The pathogenesis of dilated cardiomyopathy: current progress].
The pathogenesis of dilated cardiomyopathy (DCM) is still unknown; however, some factors that seem to play an important role in the development of the disease have recently been identified: they are enteroviral infections, immune mechanisms and genetic factors. Enteroviral infection (particularly due to Coxsackie virus B) has long been suspected to be the cause of myocarditis and subsequent DCM. However, only recent techniques of genetic engineering have been able to demonstrate the presence of enteroviral RNA in endomyocardial biopsy of patients with DCM. The role of the viral particles contained in the myocardium is still undetermined. Changes in the immune system concerning cell-mediated and humoral immunity have been recently detected. It has been suggested that an autoimmune process could be the actual cause of DCM in some patients, rather than the consequence. The immune system is strictly related to the major histocompatibility complex. As in some autoimmune diseases, a relationship between DCM and HLA class II phenotype has been found: particularly the DR4 antigen seems to be associated with a high risk of disease. Besides immunogenetic factors, other genetic factors seem to play a role in the pathogenesis of DCM. In 6-8% of cases a familial history of cardiomyopathy has been observed. In clinical studies on familial DCM different phenotypes have been shown, suggesting that different genetic mechanisms are involved in the pathogenesis of the disease. At least two main mechanisms can be hypothesized: the transmission of "predisposing" factors or a defect in proteins essential for the cardiac muscle cell function. Viral agents, autoimmune reactions, immunogenetic and genetic factors seem to cause myocardial damage individually or with complex interactions: the research should be devoted to these topics in the future.
Antibody Formation↗
Clinical aspects and haemodynamics in the follow-up of dilated cardiomyopathy and myocarditis.
Many studies on the natural history of dilated cardiomyopathy show high probability of death or of cardiac transplantation in a large percentage of patients. These studies have several methodological limitations. Our prospective study, carried out from 1971, and which evaluated 120 patients, showed improved survival in more recent years. Survival 3 years after diagnosis changed from 30% (1971-6/1981) to 88.4% (7/1986-1/1989). Thirty patients were investigated by haemodynamic exercise test to assess their haemodynamic behaviour during exercise, to evaluate the effects of pharmacological treatment and to define parameters of prognostic value. Different haemodynamic behaviours were observed. Haemodynamic investigation during exercise is useful to assess the effect of treatment and may have prognostic value. Myocarditis presents a spectrum of clinical symptoms and echocardiographic abnormalities. In patients with congestive heart failure left ventricular dysfunction is common. Patients with atrioventricular block or chest pain usually have good left ventricular function. During follow-up, improvement is possible but persistent left ventricular dysfunction is associated with a high mortality rate. When left ventricular function is good at presentation and does not deteriorate during follow-up the prognosis is good.
Cardiomyopathy, Dilated↗
Clinical and pathologic study of familial dilated cardiomyopathy.
To evaluate the occurrence of familial cases of dilated cardiomyopathy (DC), 165 consecutive patients were studied. Diagnosis of myocardial disease was based on clinical, hemodynamic, bioptic, postmortem or a combination of these criteria. Twelve patients (7% of cases) showed evidence of myocardial disease in greater than or equal to 1 relative; 27 patients with myocardial disease were detected in the 12 families, but a suspected history of myocardial involvement was present in a further 16 cases. In 6 families proband and relatives were affected by DC (total 14 cases); in 1 of these families the disease began with an atrioventricular block. In 4 families the relatives showed the presence of myocarditis at the endomyocardial biopsy. In 2 families the relatives presented a right ventricular cardiomyopathy. The mode of inheritance was autosomal dominant in 7 families, recessive in 4; X-linked pattern may be hypothesized in 1. Nine patients died under the age of 45 years: 2 of sudden death, 6 of chronic heart failure and 1 of cerebral embolism. Familial transmission is not rare. Different modes of genetic transmission (autosomal dominant, recessive and X-linked) and different forms of myocardial disease suggest that familial DC may be a multifactorial disease.
Adolescent↗
[The prognostic assessment of dilated cardiomyopathy: a follow-up of 138 patients].
A total of 138 patients with idiopathic dilated cardiomyopathy were assessed and followed-up between July 1973 and October 1985 in order to evaluate prognostic risk indicators. Of these 102 were male and 36 were female with a mean age of 49.1 years. Each patient underwent physical examination, electrocardiography, echocardiography, cardiac catheterization and coronary angiography. The mortality rate was low for the first 3 years (respectively 8, 12.5 and 20%) while it was 57.5 at the end of the 5-year follow-up period. Univariate analysis at the time of the diagnosis revealed that five factors were predictive of the clinical course at the end of the fifth year: the NYHA functional class IV (p less than 0.0001); LV ejection fraction less than 0.30 (p less than 0.01); left ventricular failure, bi-ventricular failure and left ventricular end-diastolic pressure greater than 20 mmHg (p less than 0.05). Multivariate analysis was used to determine which combination of factors could most accurately predict survival. The most important prognostic factor was again the IV NYHA functional class (p less than 0.01) and, to a lesser degree, left ventricular end-diastolic pressure (p less than 0.05). The present study underlines that the survival rate of patients with dilated cardiomyopathy depends upon the selection of patients. This can explain the low 3-year mortality found in our patients. The NYHA functional class may be a useful practical guide for cardiac transplantation.
Adolescent↗
Correlation between histomorphometric findings on endomyocardial biopsy and clinical findings in idiopathic dilated cardiomyopathy.
Multivariate analysis was used to analyze the morphometric data of endomyocardial biopsies (area, perimeter and minor diameter) of myocardial cells obtained at light microscopy by a computerized approach with 16 clinical parameters and prognosis in 52 patients with idiopathic dilated cardiomyopathy. The best morphometric parameter was "area" (R2 = 0.47). A positive correlation was found with age (p less than 0.02), interval between first symptoms and diagnosis (p less than 0.02), left ventricular end-diastolic volume (p less than 0.02), cardiac index (p less than 0.05) and echocardiographic end-diastolic diameter (p less than 0.1). A negative correlation was found with prognosis (p less than 0.02), ejection fraction (p less than 0.02), shortening fraction (p less than 0.05), echocardiographic end-systolic diameter (p less than 0.06) and mitral regurgitation presence (p less than 0.1). The parameters that provided no correlation were New York Heart Association class, left ventricular end-diastolic pressure, right atrial pressure, cardiothoracic ratio, presence or absence of heart failure, fever or alcohol intake. These findings suggest that endomyocardial biopsy may provide prognostic information and confirm clinical diagnosis.
Adult↗
[Calcium antagonists in congestive heart failure].
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Calcium Channel Blockers↗