Machiko Take

Eosinophilic disorders affecting the myocardium and endocardium: a review.

SummaryA wide range of disorders give rise to eosinophil counts >1.5×109/l (hypereosinophilia) and cardiac injury. The best known of these is eosinophilic endomyocardial disease (Löfflers endomyocardial fibrosis), which occurs as a major complication of the idiopathic hypereosinophilic syndrome. Here the heart damage appears to be a direct result of tissue injury produced by toxic eosinophil granule proteins within the heart. However, it is not known what causes the eosinophilia in these patients, why the eosinophils degranulate, or why the endocardium is especially susceptible to this type of injury. A number of parasitic infections may give rise to eosinophilic myocarditis. This is usually the result of the presence of the parasites within the myocardium where they die within inflammatory lesions, which may be extensive. Occasionally, drug reactions and rejection of a transplanted heart may produce eosinophilic myocarditis. Allergic granulomatosis and vasculitis (the Churg-Strauss syndrome), which gives rise to granulomas involving the myocardium, and eosinophilic (hypersensitivity) myocarditis usually respond rapidly to treatment with steroids. However, diffuse myocardial involvement may lead to heart failure, and some of these patients may later develop dilated cardiomyopathy. It is concluded that the heart may be affected by a variety of diseases in which eosinophils are a prominent component in the inflammatory cell infiltrates. Eosinophils themselves may contribute to some of the myocardial cell injury which occurs in these diseases, and attempts to limit this with steroids may be worthwhile in some patients.

Clinical spectrum and endomyocardial biopsy findings in eosinophilic heart disease

SummaryFourteen cases of heart disease with hypereosinophilia were analyzed employing conventional cardiologic methods, including echocardiography, cardiac catheterization, and endomycoardial biopsy. The cases were divided into four types: (1) Acute carditic (endocarditis, myocarditis, pericarditis; five cases); (2) ventricular dilation (three cases); (3) restrictive (three cases); (4) electric disturbance (three cases). Biopsy revealed significant changes in all cases. In one case of the ventricular dilation type, endomyocardial fibrosis with myocardial degeneration was seen, and in another case mural thrombus formation was shown to be present. In three cases of the restrictive type, endomyocardial fibrosis (EMF) was observed. In two cases of the electric disturbance type, minor right ventricular myocardial degeneration was observed. In two of the three cases of the carditic type and in three of eight cases in other categories, postmyocarditic changes were observed. The course of the disease compared with the type of disorder revealed a short course in the carditic type and a longer course, ranging from 2 to 24 years, with one exception, in the other types. It is also confirmed that the various histopathologic changes can be related to particular clinical presentations. We have shown that the basic changes in eosinophilic heart disease are not restricted to the endomyocardium and that they occur in various parts of the heart causing more widespread manifestations. The more comprehensive term “eosinophilic heart diease” is a preferable description.

A clinicopathologic study on a cause of idiopathic cardiomyopathy and arrhythmia and conduction disturbance employing endomyocardial biopsy

SummaryA comparative study of right ventricular histopathologic findings and clinical profiles in 174 cases with hypertrophic cardiomyopathy (HCM), 145 cases with dilated cardiomyopathy (DCM), and 241 cases with idiopathic arrhythmia and/or conduction disturbance with significant myocardial pathology [Electric disturbance type of cardiomyopathy (ECM)], totaling 560 cases, was made in order to clarify the role of viral myocarditis in these conditions. Postmyocarditic change (PMC) was defined by assessing serial biopsy findings in nine cases with acute myocarditis. The PMC was observed in three cases with HCM (1.7%), 22 with DCM (15%), and 21 with ECM (8.7%). The incidence of PMC was significantly higher in DCM and ECM than in HCM (P<0.001). The typical pattern of onset of acute myocarditis, i.e., high fever, upper respiratory infection, and gastrointestinal symptoms preceding cardiac symptoms within 10 days, was recognized in one case with HCM, eight with DCM, and 6 of 123 cases with ECM. The incidence was higher in DCM and ECM than in HCM (P < 0.05). Of 46 cases with PMC, 12 (26%) showed this pattern, on the other hand only 3 of 377 cases (0.8%) without PMC did so (P<0.0001). Familial occurrence was not found in any of the 46 cases with PMC but was found in 38 of the 377 cases without PMC (P<0.01).This study indicates that viral myocarditis may often be the causative agent of idiopathic cardiomyopathy, especially DCM and ECM. It is also noticed that familial occurrence of the cases with PMC was never seen.

Long follow-up study in patients with prior myocarditis by radionuclide methods

SummaryTen patients with previous myocarditis were evaluated to determine cardiac conditions by Tl-201 myocardial perfusion imaging and stress radionuclide ventriculography during the follow-up of 18–102 (average 56) months; the results were compared with those from ten sex-and age-matched controls. Exercise capacity by supine bicycle ergometer was reduced in patients with myocarditis. Their resting left ventricular ejection fraction (LVEF) was 57.5%±3.9%, similar to that of controls. LVEF response to stress in myocarditis was abnormal with an increment of end-systolic volume, while in the controls LVEF increased significantly during stress. Seven of the eight patients with an abnormal ejection fraction response had constant Tl-201 perfusion defects.This study indicates that latent left ventricular dysfunction is present in patients with prior myocarditis and that nuclear study is useful for long-term follow-up.

A comparative ultrastructural study on the nature of interstitial cell constituents in idiopathic myocarditis and myocardial infarction

SummaryIn order to observe the characteristics of interstitial cellular proliferation in cases with myocarditis of possible viral origin, a systematic ultrastructural analysis of the cell components in the interstitium was made employing endomyocardial biopsy at the acute (0–10 days after onset), subacute (11–25 days), and convalescent stages (26–167 days) of the disease in ten cases. For comparison, myocardial specimens from cases with myocardial infarction were taken from early autopsy cases or from tissue obtained during surgery. The dominant interstitial cells observed in the acute stage of myocarditis were fibroblasts (38.3%±17.5%, mean ±SD), macrophages (23.3%±12.1%), and lymphocytes (18.0%±18.1%); at the convalescent stage, fibrocytes (44.6%±20.2%) and fibroblasts (22.5%±8.0%) were commonly seen. In myocardial infarction, the dominant cells were macrophages (35.0%±16.0%) and neutrophils (26.0%±13.9%) at the acute stage, and lymphocytes (30.0%±17.8%), plasma cells (27.1%±20.0%), and macrophages (26.4%±11.4%) at the late stage. Thus, some differences between the two diseases could be recognized.

Hemodynamic studies and response to a combined therapy of nitroglycerin ointment and dopamine in patients with acute myocarditis

SummaryLeft ventricular performance was assessed in ten patients with acute myocarditis during the acute stage (within the first 3 days after the onset of cardiac symptoms) and during the convalescent phase (3–5 weeks later). In nine, the diagnosis was confirmed by endomyocardial biopsy during the acute stage, when left ventricular function was markedly reduced, i.e., cardiac index 1.53±0.33 1/min/m2 (mean ±SD), left ventricular stroke work index 14.1±3.9 g/beat/m2, pulmonary capillary pressure 25.9±4.3 mm Hg, and systemic vascular resistance 27.9±9.4 R units. During convalescence, seven patients improved clinically with normal cardiac function and in three it remained impaired. Cardiovascular response to nitroglycerin ointment in three patients and a combination of dopamine and nitroglycerin ointment in five were compared. Nitroglycerin ointment reduced pulmonary capillary pressure by an average of 28.5% (P<0.05) and systemic vascular resistance by 26.8%, while the cardiac index increased by 34.1% (P<0.05) and left ventricular stroke work index by 30.3% (P<0.01). The combined therapy was more effective, with a reduction of pulmonary capillary pressure by 30.4% (P<0.05) and systemic vascular resistance by 27.5% (P<0.05), accompanying an increase in cardiac index by 53.5% (P<0.005) and left ventricular stroke work index by 63.5% (P<0.01), with little change in the double products. This study suggests that serial hemodynamic monitoring accurately evaluates cardiac function, selection of appropriate therapy, and the hemodynamic effects of treatment in patients with acute myocarditis. In particular, the combination therapy has beneficial advantages without causing a significant change in the myocardial oxygen consumption.

Catheter Biopsy Assessed Cardiomyopathic and Postmyocarditic Changes in Cases with Atrioventricular or Intraventricular Conduction Disturbance

To determine the cause of A-V block or intraventricular conduction disturbance (IVCD) at the clinical level is usually difficult. Our experience with endomyocardial biopsy which exceeds 1300 cases has revealed that biopsy is useful in diagnosing and assessing myocardial disease. A serial biopsy study in 10 cases with acute viral myocarditis has enabled us to define the histopathological criteria of postmyocarditic change (PMC). Eighty-eight cases with A-V block and 51 cases with IVCD underwent biopsy in order to better understand the nature and incidence of myocardial change. Those cases where the ECG abnormalities were the most pertinent to the clinical findings were selected for this study. Accordingly, 91 of 139 cases were idiopathic. Diagnosis of cardiac sarcoidosis in 2 cases and of cardiac amyloidosis in I case were made with the biopsy. Twenty-three of 91 idiopathic cases (25%) showed significant myocardial pathology. In 38 of 91 idiopathic cases (42%), PMC was detected. His-bundle electrogram revealed that in cases with A-V block, H-V prolongation was correlated with the significant pathology. Most of the cases were not classified into either dilated or hypertrophic cardiomyopathy but were classified according to our proposed term: “Arrhythmia-conduction disturbance type of cardiomyopathy”. A long-term follow up of up to 13 years in 87 cases among the 139 cases revealed that the apparent heart muscle diseases such as sarcoidosis, amyloidosis, dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM) were more prone to have short prognosis. It is concluded that in those cases where the A-V block or IVCD exists and when pacemaker implantation is considered, biopsy is useful in making diagnosis and also in recognizing the nature of the disease and its severity.