Fibroplastic parietal endocarditis with eosinophilia: Löffler's endocarditis

Abstract

Three cases with autopsy proof of fibroplastic parietal endocarditis with eosinophilia are described in patients who were of Cape Coloured stock. These are the first cases to be described from Southern Africa. A review is made of thirty-seven cases proved at autopsy of this same condition; these together with the three cases reported herein represent the total literature available on this subject. The majority of cases so far described have been from continental Europe, few having been seen elsewhere. The clinical diagnosis depends on a varying picture. There may be a systemic illness with onset which can be acute, presenting with abdominal symptoms, cerebral symptoms or (frequently) with complaints of a respiratory nature. Attacks of bronchospasm may be present over a long period of time. The onset may be more insidious with vague ill health, joint and muscle pains and loss of weight. Sooner or later cardiac symptoms appear, with reduction in effort tolerance and frequently with signs of congestion of the liver and ascites and a raised venous pressure. The heart may not be enlarged or only slightly enlarged, thus resembling in appearance a constrictive pericarditis. However, murmurs of mitral incompetence appear frequently but there also may be those of mitral stenosis or tricuspid incompetence. The electrocardiogram shows changes in the S-T segment and T wave with low voltage, suggestive of myocardial damage, such as is found in myocarditis or in constrictive pericarditis. The roentgenograms may show cardiac enlargement and the appearance of congestive changes in the lungs and the presence of pleural effusion or even areas of infiltration. Rarely a patient may have nephritic signs and may be hypertensive. There may be evidence of emboli, particularly to the spleen and to the lungs. The blood picture is of great aid because leukocytosis is frequent and eosinophilia is present at one stage or another of the illness. It appeared from our own cases that eosinophilia may be absent early in the illness and again in the later stages. The erythrocyte sedimentation rate may be raised or normal. The anatomic changes can be shown to depend on the stage of the disease. During the acute phase macroscopic findings in the heart are minimal. Microscopically, however, there is evidence of inflammation with cellular infiltrates, the predominant cells being eosinophils. At this stage, too, there may be eosinophilic arteritis in the lungs, brain, kidneys and other organs. The eosinophil infiltrates may be present also in lymph nodes, spleen and portal tissue of the liver. After the initial stage, mural thrombi can be formed which then lead to the later subchronic and chronic stages. When Löffler's endocarditis is old, the heart is usually enlarged, often as a result of hypertrophy, and displays thrombi and a greyish white thickening of the endocardium. Although all parts of the heart may be involved, the ventricles are more affected than the atria and the left ventricle more frequently than the right. Incompetence of the mitral or tricuspid valve can be caused by shortening and thickening of the chordae tendineae. The inflammation may extend from the endocardium into the myocardium and even through the entire thickness of the ventricular wall. The microscopic findings in the late stages of Löffler's endocarditis are those of thickening of the endocardium by collagen and elastic fibres. Inflammatory infiltrations by lymphocytes, eosinophils and a few plasma cells may be present and scar tissue may extend into the myocardium and in places throughout the whole thickness of the wall. The thebesian veins show dilatation and a fibrous thickening of their walls, the myocardial fibres are often hypertrophie. A basophilic degeneration of the myocardium is present in all three of our cases. It is believed that there are at least four different types of parietal endocarditis of unknown etiology: the endomyocardial fibrosis described by Davies, the endocardial collagenosis described by Becker, the parietal fibroplastic endocarditis with eosinophilia described by Löffler, and a neutrophil parietal endocarditis which we consider should be regarded separately as a fourth type. These conditions can be differentiated fairly easily during the acute stage, depending on the microscopic appearances. Once cardiac failure has supervened, the condition appears to be inevitably fatal, although the duration of illness may vary from no more than a few hours to as much as six years. So far no form of therapy has been of specific value. In one of our patients prednisone was capable of producing a remission during the acute phase of the illness. However, intractable heart failure developed later. The available literature strongly suggests that the etiology of this condition is dependent on an allergy.