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Right ventricular endomyocardial biopsy in chronic Chagas' disease.

Right ventricular endomyocardial biopsy was used to study myocardial involvement in 42 patients with chronic Chagas' disease. Patients were divided into three groups: group A included 16 patients with normal ECGs, normal chest x-rays, and no symptoms; group B included 15 patients with abnormal ECGs and no cardiomegaly; and group C included 11 patients with abnormal ECGs and cardiomegaly. Biopsy fragments were analyzed for hypertrophy, degeneration of myocardial fibers, and interstitial changes such as edema, fibrosis, and inflammatory infiltrate. In group A, 5 of 16 biopsies exhibited none of the previously mentioned alterations. The frequencies pathologic alterations in groups A, B, and C, respectively, were: hypertrophy 31%, 66%, and 100%; degeneration 50%, 86%, and 81%; edema 43%, 46%, and 36%; fibrosis 12%, 33%, and 54%; and inflammatory infiltrate 37%, 66%, and 65%. These data suggest that myocardial lesions of Chagas' disease represent a continuous progression from fiber destruction to substitution by fibrosis, with compensatory hypertrophy; these data also suggest that cardiac dilatation occurs when the extent of fibrosis no longer allows for efficient compensatory hypertrophy.

Adolescent↗

Heart transplantation--a two-year experience.

In July 1983, a heart transplant program was initiated. Up to September 1985, 72 orthotopic transplants in 69 patients (62 men, 7 women, age 9 to 55 years, mean 40.1 years) have been performed. All patients suffered from end-stage heart failure, which was due to coronary artery disease in 15 patients, congestive cardiomyopathy in 53 patients and endocardial fibrosis in one woman. All patients survived the operation, but there were 6 deaths within the first 30 postoperative days. Eight more patients died subsequently. Causes of death were rejection in 6, infection in 3, cerebral hemorrhage in 2, sudden death in 2 and pulmonary embolism in one patient. Actuarial survival at one and two years was calculated at 75%. The detection of allograft rejection was the major postoperative problem. This was achieved by serial endomyocardial biopsy and myocardial voltage monitoring via a telemetry pacemaker system. The lowest rate of organ toxicity, rejection and infection was achieved using a triple immunosuppressive regime including Azathioprine, Cyclosporine A and steroids with initial doses of antithymocyte globulin. It is concluded that heart transplantation can be regarded as a routine procedure for patients with intractable heart failure. The operative risk is limited, and an elaborate immunosuppressive regimen makes long-term survival possible without obvious allograft deterioration. Cardiac transplantation should be seriously considered in patients under 55 years, who suffer from life-threatening heart failure not amenable to other modes of therapy.

Adolescent↗

[Histopathological studies of endomyocardial biopsy on the children with Kawasaki disease].

Since there has been many reports on the coronary artery lesions in the patients with Kawasaki disease, but only a few reports on histopathological investigation employing endomyocardial biopsy, histopathological study was performed in eighteen children of Kawasaki disease with coronary artery lesions and eighteen children of Kawasaki disease with intact coronary artery, aged from one year and ten months to fourteen years. There were twenty males and sixteen females. Comparing Kawasaki disease who had coronary artery lesions with those not, there was no striking difference in histologic findings. Kawasaki disease without coronary artery lesions revealed myocellular hypertrophy, degeneration of myocytes, disarray, interstitial fibrosis and endocardial changes in 44%, 61%, 11% and 44%, respectively. Among Kawasaki disease who had coronary artery lesions, children with coronary artery stenosis showed a higher incidence of histological abnormalities than those with coronary artery aneurysm. Some cases of Kawasaki disease were recognized to have significant myocardial abnormalities even in three to six years after onset, which seemed to persist whether or not they would have coronary artery lesions. Since Kawasaki disease who would have myocardial damages might have the potential for developing cardiomyopathy, careful attention should be payed to myocardial lesions as well as sequelae of coronary artery lesions.

Adolescent↗

Different effects of antihypertensive therapies based on losartan or atenolol on ultrasound and biochemical markers of myocardial fibrosis: results of a randomized trial.

BACKGROUND: In hypertensive left ventricular hypertrophy (LVH), myocardial texture is altered by a disproportionate increase in fibrosis, but there is insufficient clinical evidence whether antihypertensive therapy or individual agents can induce regression of myocardial fibrosis. METHODS AND RESULTS: We compared the effects of an angiotensin II receptor antagonist with a beta-blocker on myocardial collagen volume (assessed by echoreflectivity and serum collagen markers) in 219 hypertensive patients with echocardiographically documented LVH. Patients were allocated randomly to receive losartan 50 to 100 mg/d (n=111) or atenolol 50 to 100 mg/d (n=99) with or without hydrochlorothiazide 12.5 to 25 mg/d for 36 weeks. Echoreflectivity analysis was conducted on ultrasound tracings of the midapex septum with specifically designed and validated software. A color histogram of reflecting echoes was obtained, and its spread (broadband [BB], previously shown to correlate directly with collagen volume fraction on endomyocardial biopsies) was used as the primary outcome measure. Mean color scale and serum markers of collagen synthesis (PIP, PIIIP) or degradation (CITP) were secondary outcome variables. Echoreflectivity analysis proved feasible in 106 patients (losartan 52, atenolol 54). Losartan reduced BB over 36 weeks (from 114.5 to 104.3 color levels, P<0.02), whereas atenolol treatment was associated with an increase in BB (from 109.0 to 113.6 color levels, P=NS), the difference between treatments being -12.8 color levels (95% CI -23.6 to -2.0, P=0.02). Secondary end points (mean color scale and collagen markers) also changed in the direction of decreased collagen in patients receiving losartan, but differences between groups were not statistically significant. CONCLUSIONS: In hypertensive patients with LVH, losartan decreases myocardial collagen content, whereas atenolol does not. The difference between the 2 treatments is statistically significant.

Adrenergic beta-Antagonists↗

The relation of alcoholic myopathy to cardiomyopathy.

OBJECTIVE: To evaluate the relation between skeletal muscle disease (myopathy) and degenerative changes in cardiac muscle (cardiomyopathy) in patients with chronic alcoholism. DESIGN: A cross-sectional study. SETTING: University medical center. PARTICIPANTS: Group A included 24 patients with chronic alcoholism who had dilated cardiomyopathy; group B, 24 patients with chronic alcoholism who had normal cardiac function; group C, 12 patients with dilated cardiomyopathy because of coronary heart disease; group D, 12 patients with idiopathic dilated cardiomyopathy; group E, 24 normal participants; and group F, 5 young men who died suddenly in traffic accidents. MEASUREMENTS: Clinical assessment of muscle strength, echocardiography, radionuclide cardiac angiography (groups A to E), muscle biopsy (groups A, B, E), endomyocardial biopsy of the left ventricle (group A), and examination of postmortem specimens of the left ventricle (group F). RESULTS: Alcoholic patients with cardiomyopathy had less muscle strength than did alcoholic patients with normal cardiac function, patients with idiopathic dilated cardiomyopathy, and patients with coronary heart disease (all P < 0.01). Among alcoholic patients with cardiomyopathy, 20 of 24 (83%) had histologic findings of skeletal myopathy compared with 1 of 24 (4%) alcoholic patients with normal cardiac function (P < 0.001). Interstitial fibrosis occurred in all cardiac biopsy specimens, hypertrophy of the myocytes occurred in 95%, and myocytolysis occurred in 83%. Those patients with more severe cellular hypertrophy and interstitial fibrosis of the myocardium had a greater decrease in deltoid muscle strength and had worse histologic myopathy. CONCLUSIONS: Diseases of skeletal and cardiac muscle in patients with chronic alcoholism are clinically and histologically related. The presence of muscle weakness in an alcoholic person suggests the likelihood of an accompanying cardiomyopathic abnormality.

Adult↗

[Cardiac mast cells in myocardial diseases].

Mast cells play a role in inflammation and immunological reactions. Cardiac mast cells with their granules are demonstrated easily by toluidine blue staining. We evaluated cardiac mast cells in endomyocardial biopsy specimens in patients with acute myocarditis (n = 17), idiopathic dilated cardiomyopathy (n = 17), idiopathic hypertrophic cardiomyopathy (n = 17) and control subjects (n = 12). Cardiac mast cells increase to an extreme degree in patients with acute myocarditis (2.4 counts/mm2) and increase relatively in patients with idiopathic dilated cardiomyopathy (1.4 counts/mm2). Patients with idiopathic hypertrophic cardiomyopathy (0.4 counts/mm2) were similar to control subjects (0.5 counts/mm2). Cardiac mast cells increased in accord with the severity of cellular infiltration and of interstitial fibrosis except for some cases with very severe fibrosis. In the acute myocarditis group, cardiac mast cells were well demonstrated in the early stage of the illness. But degranulations of mast cells did not give us any significant information in this study. Evaluation of cardiac mast cells will provide us with a new aspect in studying primary myocardial diseases.

Adolescent↗

Significant myocardial pathology and increase of alpha 1-adrenergic receptor number affecting the arrhythmogenic condition in cases with ventricular tachycardia.

To study the pathogenesis of idiopathic ventricular tachycardia with left bundle branch block morphology (LBBB-VT), histopathological findings in 34 patients and adrenergic receptor (AR) density obtained by micro-autoradiography in 11 patients were analyzed, using endomyocardial biopsy samples. According to the ventricular volume, we divided the patients into 3 groups. Group A patients (n = 8) were diagnosed as having arrhythmogenic right ventricular dysplasia (ARVD) showing right ventricular enlargement, group B patients (n = 7) showed decreased left ventricular function and/or enlarged left ventricle, and group C (n = 19) included patients with idiopathic ventricular tachycardia (VT) without enlargement or dysfunction of either ventricle. Histologically, there was a high incidence of significant pathology showing myocardial hypertrophy, degeneration, abnormal branching, and interstitial fibrosis in all groups (group A, 100%; group B, 86%; group C, 56%). There was a higher incidence of fatty tissue infiltration in groups A (100%), B (71%), C (48%) than in the control groups. As for AR, specific grains of alpha 1- and beta-AR were 23.0, and 18.3 (grains/25 x 25 mm square) respectively, in patients with LBBB-VT. The number of alpha 1 grains in patients with LBBB-VT was apparently higher than in the control group, sick sinus syndrome (SSS; 11.2), and the beta-AR density in the LBBB-VT group was the same as in the control group (SSS; 15.4). We concluded that the significant pathology in cases with VT might affect the arrhythmogenic condition. Moreover, these results suggested that the increase in the number of alpha 1-AR might have a great influence in idiopathic VT.

Adult↗

Small vessel pathology and coronary hemodynamics in patients with microvascular angina.

We studied the ultrastructure of cardiac myocytes and small blood vessels obtained by endomyocardial biopsy from 21 patients with microvascular angina. Ischemic ST segment depression during atrial pacing was recognised in all the patients who had normal coronary arteriograms and biopsy tissues were examined by light and electron microscopy. In patients with microvascular angina, insufficient increases in coronary sinus blood flow and in myocardial oxygen consumption measured with a Webster's catheter were apparent during atrial pacing. Biopsy samples under the light microscope showed evidence of myocardial hypertrophy and sclerosis of small arteries and arterioles with perivascular fibrosis in 18 of 19 (95%) patients. Electron microscopy revealed that many endothelial nuclei in capillaries were swollen and that lumina of small arteries and arterioles were irregularly narrowed with proliferated and deformed medial smooth muscle cells. These findings suggest that disturbances in the coronary microcirculation in these patients is responsible for the ischemic changes in electrocardiograms.

Aged↗

Venticular expression of atrial and brain natriuretic peptides in patients with myocarditis.

We analyzed the ventricular expression of atrial and brain natriuretic peptides (ANP and BNP) in patients with myocarditis. Immunohistochemical analysis of endomyocardial biopsy specimens showed ANP and BNP immunoreactivity in the early myocarditis group (ANP in 4/10 and BNP in 3/10) and the late myocarditis group (ANP and BNP in 4/10), but not in the controls (0/8). Hemodynamic parameters, such as left ventricular volume indexes, pulmonary capillary wedge pressure, and left ventricular end-diastolic pressure, were higher and the cardiac index and ejection fraction were lower in the patients positive for ANP and/or BNP. Histological changes, including myocyte size, cellular necrosis, inflammatory infiltrates and fibrosis, were more severe in the immunohistochemically positive biopsy specimens. In the autopsy hearts, ANP- or BNP-positive myocytes were noted in the chronic myocarditis or postmyocarditis group, but not in acute fulminant myocarditis or in normal controls. Both ANP and BNP were predominantly localized in the residual myocytes edging the myocardial lesions, and also in the myocytes just beneath the left ventricular endocardium. This study demonstrated augmented ventricular ANP and BNP expressions in patients with myocarditis, and suggested that regional stress is important in the augmentation of these peptides as well as hemodynamic stress.

Adolescent↗

Effects of a new cardiotonic agent, "TA-064", in patients with dilated cardiomyopathy--relationship between cardiac effect of TA-064 and severity of myocardial lesion.

In 18 patients with dilated cardiomyopathy (DCM), the effects of a new cardiotonic agent, TA-064, given in both consecutive and intermittent (3 days on, 11 days off) oral doses were studied for 3 months by echocardiography and endomyocardial biopsy. After 3 months of consecutive administration, 11 patients (61%) had improved symptomatically and the %FS increased (p less than 0.001) and LVDd decreased (p less than 0.05), but the other 7 patients had not improved. At the pretreatment state these 7 patients in whom TA-064 was not effective had smaller %FS (p less than 0.01) and larger LVDd (p less than 0.05) than the 11 patients in whom the drug was effective. The non-effective group also had more severe myocardial fibrosis (p less than 0.05) and cellular hypertrophy (p less than 0.01) than the effective group. After 3 months of intermittent administration in 10 patients in whom consecutive administration had been proved effective, 7 patients sustained symptomatic improvement and increased %FS (p less than 0.01), but the other 3 patients did not sustain the improvement. The latter group had smaller %FS, larger LVDd and more severe myocardial fibrosis than the former group at the pretreatment state. These results indicate that the effects of TA-064 are dependent on the severity of basal cardiac function and myocardial damage, and that in patients with milder DCM, the effects can be sustained by intermittent administration.

Adult↗

Prognostic significance of pathological parameters of endomyocardial biopsy in clinical outcome of patients of dilated cardiomyopathy--I. Quantitative morphometric analysis.

Quantitative evaluation of endomyocardial biopsies from cases of dilated cardiomyopathy (DCM) was carried out using IBAS KONTRON image analyser with a view to recognise parameters that may be diagnostic and reflect prognosis of the disease. Mean fibre and nuclear diameter, percentage area occupied by myofibres and mean perimeter of the muscle fibres were assessed. Haemodynamic observations were correlated with morphological findings. Percentage area occupied by myofibres was least in cases of DCM. It appears that the muscle mass in cases of DCM decreases with a corresponding increase of fibrosis within the interstitium. This parameter showed a significant direct correlation with left ventricular ejection fraction and an inverse relationship with left ventricular end diastolic pressure. Thus the percentage area occupied by myofibres indicated the severity of DCM as it correlated well with the haemodynamic parameters. Its prognostic role, however, needs to be further investigated on a larger number of cases and follow up studies.

Adolescent↗

Age dependency of left ventricular diastolic function in pressure overload hypertrophy.

OBJECTIVES: We sought to evaluate whether age is a determinant of left ventricular (LV) pressure overload hypertrophy and whether diastolic function influenced the aging process. BACKGROUND: The adaptation of the left ventricle to chronic pressure overload is a complex process of hormonal, structural and hemodynamic factors. Different responses in the elderly patients have been described. METHODS: LV biplane cineangiography, micromanometry and endomyocardial biopsies were carried out in 57 patients with pure or predominant aortic stenosis. Patients were classified into a senior (< 60 years, mean age +/- SD 46 +/- 10 years, n = 35) and an elderly (< 65 years; mean age 70 +/- 4 years, n = 22) study group. LV systolic function was evaluated from biplane ejection fraction and midwall fractional shortening, whereas diastolic function was assessed from the time constant of LV pressure decay, peak filling rate and the constant of myocardial stiffness. Biopsy samples were examined morphometrically for interstitial fibrosis, fibrous content, muscle fiber diameter and volume fraction of myofibrils. RESULTS: Gender distribution and the severity of aortic stenosis were comparable in the two patient groups. LV peak systolic and end-diastolic pressures were significantly higher in the elderly than in the senior group. LV ejection fraction and midwall fractional shortening were comparable in the two groups. The time constant of relaxation and the myocardial stiffness constant were greater in the elderly than in the senior group whereas the early peak filling rate was significantly reduced in the elderly group. Interstitial fibrosis was increased, although not significantly (p < 0.06), and fibrous content was enhanced (p < 0.001) in elderly patients with respect to the senior group. There was a linear correlation between age and myocardial stiffness (r = 0.55), p < 0.0001) and an inverse relation between age and early peak filling rate (r = 0.52, p < 0.0001). CONCLUSIONS: In the presence of a comparable degree of aortic valve stenosis, elderly patients (> 65 years) present with more severe LV hypertrophy than do senior patients (< 60 years). Therefore elderly patients have a more pronounced impairment of LV diastolic function, whereas systolic function is preserved. Thus, there is an age dependency of LV pressure overload hypertrophy that can be explained by the longer duration of pressure overload or an exhaustion of the adaptation process in the elderly.

Adaptation, Physiological↗

Clinical profile of restrictive cardiomyopathy.

The characteristic hemodynamic features of restrictive cardiomyopathy (normal or reduced cardiac index, normal ventricular systolic function, and "dip and plateau" early in diastole) are traditionally associated with pathologic evidence of inflammation, infiltration and fibrosis. Prognosis is usually poor. Nine patients with restrictive hemodynamic features were recently identified in our laboratory; six were males, three were females, and ages ranged from 23-57 years (mean 47 years). Only one was asymptomatic. Chest pain, dyspnea on exertion and fatigue were the most common symptoms. Echocardiography revealed various degrees of left ventricular wall thickening, but no significant pericardial effusion, pericardial thickening or calcification. Mean left ventricular end-diastolic pressure was 25 mm Hg, cardiac index 2.8 l/min/m2 and ejection fraction 0.63. Endomyocardial and pericardial biopsies, obtained in two patients, were normal. Follow-up (mean 22 months, range 16-42 months) revealed no cardiac deaths. These findings support the hypothesis that the restrictive hemodynamic profile does not necessarily indicate the presence of a specific pathologic process in the subendocardium or myocardium and that the prognosis is not necessarily ominous. The common pathophysiologic feature for this syndrome appears to be reduced ventricular diastolic compliance, but the etiology in many cases is unclear.

Adult↗

Histopathologic aspects of viral myocarditis and its diagnostic criteria.

The morphologic criteria in diagnosing myocarditis are detailed. In fulminant cases, apart from the inflammatory infiltrate which often consists of chronic inflammatory cells, necrosis is found, frequently in the form of myocytolysis. Two groups of patients are analyzed. The first consisted of 214 cases who were clinically suspected of suffering from myocarditis. In 50% of these cases, the clinical suspicion was confirmed by morphologic examination of tissue obtained by endomyocardial biopsy. The other group of patients were suspected of having dilated cardiomyopathy and consisted of 1200 patients; in 300 of these patients, myocarditis was diagnosed morphologically by biopsy. Following sequential biopsies monitoring the response to treatment with corticosteroids and immunosuppressive agents, a classification into active, ongoing, resolving (healing), or resolved (healed) forms has been advanced. The different stages depend on the severity of the inflammatory infiltrate, the site of the inflammatory cells, the presence or absence of necrosis of adjacent myocardial fibers, and the degree of fibrosis. It has been emphasized that clear concepts and a uniform approach are essential in diagnosing myocarditis, not only to achieve precise diagnosis, accurately monitoring the response to therapy, but also in helping to establish the pathogenetic pathways for certain forms of cardiomyopathy.

Acute Disease↗

Expression of matrix metalloproteinase activity in idiopathic dilated cardiomyopathy: a marker of cardiac dilatation.

BACKGROUND: Idiopathic dilated cardiomyopathy (DCM), ventricular systolic dysfunction and chamber dilatation are accompanied by architectural remodeling, wall thinning and cardiac myocyte slippage. Recent work has demonstrated an association between collagen degradation and an increased expression of matrix metalloproteinases (MMPs). Accordingly, we have sought to correlate (a) collagen degradation with MMP elevations and, (b) assay the neutralizing potential of a known inhibitor of MMP, tetracycline on MMPs in DCM. METHODS: Assessment of LV volume and shape by 2-D echocardiography was performed. Light microscopic assessment of histopathology in picrosirius red stained biopsy samples of 11 DCM patients and six post-transplant patients was performed. Zymographic estimation of MMP activity and influence of tetracycline on MMP activity was assessed. RESULTS: Small amount of interstitial collagen was noted in the control group, whereas in the DCM hearts, chamber dilatation was associated with areas of scanty myocyte necrosis, islands of excess collagen, and focal areas of absent or scanty collagen with intact myocytes. In cardiomyopathic tissue, collagenase activity was markedly elevated at 63% compared with 8% in post-transplant tissue. Tetracycline at a concentration of 285+/-10 microM (IC50) inhibited collagenase activity by 50% in cardiomyopathic tissue. CONCLUSIONS: Areas of focal interstitial collagen accumulation were accompanied by collagen fiber lysis and increased collagenase activity in dilated cardiomyopathy. This enhanced collagenolytic activity found in endomyocardial biopsy tissue was inhibited by tetracycline. The non-antibiotic property of tetracycline may be of potential value in the prevention of ventricular dilatation in idiopathic dilated cardiomyopathy.

Adult↗

Significance of signal-averaged electrocardiography in relation to endomyocardial biopsy and ventricular stimulation studies in patients with ventricular tachycardia without clinically apparent heart disease.

Signal-averaged electrocardiography (ECG) was performed in 38 patients (mean age 38 years, range 15 to 70) with ventricular tachycardia who had no clinical evidence of structural heart disease. Spontaneous ventricular tachycardia was nonsustained in 23 patients and sustained in 15. None of the patients had symptoms of heart failure or ischemic heart disease, and at cardiac catheterization none had significant coronary artery disease or left ventricular wall motion abnormalities. In addition, all patients underwent left and right ventricular endomyocardial biopsy and ventricular stimulation studies. Signal-averaged ECG was performed and late QRS potentials were defined with use of Simson's method. Late QRS potentials were detected in a minority (18%) of patients including 2 of 23 with nonsustained and 5 of 15 with sustained (p = NS) ventricular tachycardia. Fifteen patients (40%) had abnormal endomyocardial biopsy results and these findings were more common in patients with sustained than in those with nonsustained ventricular tachycardia (9 of 15 versus 6 of 23, p less than 0.05). Late potentials were associated with abnormal endomyocardial biopsy findings (6 of 15 versus 1 of 23, p less than 0.01). An increase in fibrous tissue was the most frequent histopathologic abnormality; this increase was quantified by morphometric methods and compared with biopsy findings in normal control subjects. In the control group the proportion of collagen in relation to myocytes was less than 10%. All patients with both late potentials and abnormal biopsy findings had a greater than 15% ratio of collagen to myocytes in at least one specimen and the biopsies revealed marked interstitial fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Overexpression of tumor necrosis factor (TNF)alpha and TNFalpha receptor I in human viral myocarditis: clinicopathologic correlations.

Proinflammatory cytokines, including tumor necrosis factor (TNF)alpha, have been recognized as important physiopathogenetic factors in the initiation and continuation of inflammatory cardiomyopathies. Experimental and preliminary human studies have demonstrated that TNFalpha plays a crucial role in enteroviral-induced myocarditis. In this study, we investigated the expression of TNFalpha and both its receptors (TNFRI and TNFRII) in both viral and nonviral myocarditis. Myocardial expression of TNFalpha was then correlated with different clinical and pathologic findings. TNFalpha expression was investigated in endomyocardial biopsies obtained from 38 patients with myocarditis and from eight control subjects by using reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry. Viral etiology was diagnosed by PCR in 20 cases: enterovirus in seven, Epstein-Barr virus in four, hepatitis C virus in three, adenovirus in two, influenza virus in two, cytomegalovirus in one, and double infection adenovirus and enterovirus in one. Immunohistochemistry was also used to analyze both TNFalpha receptors (RI and RII). A semiquantitative analysis was employed (score 0-3) for necrosis, inflammation, fibrosis and immunohistochemical findings. TNFalpha mRNA and TNFalpha protein were significantly more present in viral myocarditis than in nonviral myocarditis (16/20 vs 3/18, P=0.001). Remarkable immunostaining was observed for both receptors, particularly TNFRI. Histological analysis revealed that myocardial necrosis (mean score 1.89 vs 1.15, P=0.01) and cellular infiltration (mean score 2.26 vs 1.78, P=0.05) were more prominent in TNFalpha-positive cases. Among TNFalpha-positive cases, the greater TNFalpha mRNAs, the more impaired was cardiac function. Our findings suggest that the expression of TNFalpha may play an important role in the pathogenesis of viral myocarditis of any etiology and may influence the severity of cardiac dysfunction. Cytokine effects are more strictly linked to overexpression of TNFRI.

Adolescent↗

Clinical findings in acute viral myocarditis. With special attention to experimental and immunological evidence.

According to analysis of 40,000 autopsies, the incidence of myocarditis is approximately 3.5%, the diagnosis of which had not been established in the majority prior to death. The clinical characteristics of myocarditis encompass a wide spectrum from an asymptomatic course to sudden cardiac death. Symptoms and findings of congestive heart failure or an inflammatory virus disease may be present. There is usually evidence of nonspecific clinical, radiologic, electrocardiographic, echocardiographic and blood chemistry abnormalities. In the presence of myocarditis, gallium scintigrams are generally pathologic. Virologic and serologic studies may have an important, albeit not decisive, role in establishing the diagnosis. In the acute phase, endomyocardial biopsy can document inflammatory changes. For the most part, treatment is symptomatic. Ventricular arrhythmias and high-grade conduction disturbances prerequisite vigilant monitoring as well as adequate medical and, if indicated, electrical therapy. In addition to conventional treatment, steroids, more recently, in combination with azathioprine, have been employed in patients with subacute and chronic myocarditis. The course of myocarditis is frequently benign although, in some cases, congestive heart failure may develop. Laboratory studies in DBA/2 mice with congestive heart failure subsequent to surviving myocarditis have shown myocardial fibrosis and hypertrophy without mononuclear cell infiltrates indicative of transition to dilated cardiomyopathy.

Animals↗

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