Natsuko Kubo

Changes in the peripheral eosinophil count in patients with acute eosinophilic myocarditis

In many cases, the diagnosis of eosinophilic myocarditis is suggested by an elevated peripheral blood eosinophil count. However, no detailed studies have been performed on the sequential changes in the initial peripheral blood eosinophil count over the course of the disease. We measured the peripheral blood eosinophil count at the time of presentation in eight patients with eosinophilic myocarditis proven by endomyocardial biopsy and intermittently thereafter. The eosinophil count at the time of onset was ≪500/mm3 in four patients, ≫500/mm3 but ≪1 000/mm3 in three patients, and ≧1 000/mm3 in one patient. In three of the four patients with an initial eosinophil count of ≪500/mm3, an increase to ≧500/mm3 occurred 7–12 days after the onset. The remaining patient did not develop peripheral eosinophilia. In conclusion, in the early stage of eosinophilic myocarditis, peripheral hypereosinophilia is not present initially in some patients, and may not develop during the course of the illness in a subset of these patients.

Feasibility of diagnosing chronic myocarditis by endomyocardial biopsy

SummaryIn studies of all the layers of autopsied hearts from patients with chronic myocarditis, local clusters of lymphocytes are frequently noted, in contrast with hearts obtained from patients with acute myocarditis. Myocardial biopsy specimens, however are no larger than about 2mm×3mm. With this in mind, the present study was undertaken to determine whether chronic myocarditis can be diagnosed by endomyocardial biopsy. Specimens were obtained from seven patients in whom chronic myocarditis was confirmed by the clinical course and by autopsy findings. In H&E stained specimens, sites corresponding to the biopsy sites in both ventricles (right ventricular free wall, right ventricular side of the ventricular septum, left ventricular lateral wall) were selected at random (five sites each from the right and left ventricles in each patient) and examined under a light microscope. A mean of 5 or more lymphocytes per visual field (by light microscopy at 400-fold magnification), a proposed quantitative diagnostic criterion of myocarditis, was noted in the right ventricle in three patients (5 lymphocytes in two patients and 6 in one patient) and in the left ventricle in one patient (5 lymphocytes). Also, when the presence of lymphocyte clusters, considered to be a characteristic feature of chronic myocarditis, was determined, clusters of 20 or more lymphocytes per visual field were found in the same patients as those mentioned above, namely, in three patients (42.8%) in the right ventricle, as mentioned above, and in one patient (14.3%) in the left venricle. At the sites of these lymphocyte clusters, findings such as degenerative changes of the myocardial cells and interstitial fibrosis were also associated, making possible a diagnosis of myocarditis. Therefore, in chronic myocarditis, even if five specimens are obtained by right ventricular biopsy, in approximately one half of patients the diagnosis of chronic myocarditis will be missed because of sampling errors.

Lesions in side branches of arteries having undergone percutaneous transluminal coronary angioplasty: A histopathologic study

Percutaneous transluminal coronary angioplasty (PTCA) may cause occlusion in side branches. No histologic studies, however, have been made on side branches of the arteries in which PTCA has been performed. A histologic study was therefore made to explain the effect of PTCA on side branches. Histologic specimens were prepared by serial step sectioning from 15 side branches of 10 autopsied cases that had undergone PTCA. The results of examination by light microscope were as follows: (1) Stenoses due to PTCA were seen in seven branches (46.7%). (2) The stenoses were classified into three types: (a) stenosis due to blocking of the orifice of a side branch by the disrupted portion of the intima of the main artery (one branch); (b) stenosis due to medial dissection of the main artery or further dissection occurring even in the side branches (three branches); and (c) stenosis due to fragmentation of the internal elastic lamina of the main artery accompanied by proliferation of smooth muscle cells even in the side branch (three branches). It is now clear that stenosis is caused in side branches long after PTCA. Extra care is required when major side branches exist in the portion where this procedure is to be performed.

Relief of Left Ventricular Outflow Obstruction by Cibenzoline in a Patient With Fabry’s Disease A Case Report

A 46-year-old man was admitted for further evaluation of exertional chest discomfort. One family member had experienced sudden death, and 2 others had died of heart failure, including 1 known to have had Fabry’s disease. The patient was also diagnosed with Fabry’s disease, based on reduced leukocyte a-galactosidase A activity, 2.0 nmol/mg protein/hour, as well as endomyocardial biopsy findings of marked sarcoplasmic vacuolization of cardiac muscle cells by light microscopy and lamellated “zebra bodies” in the cytoplasm shown by electron microscopy. Echocardiography disclosed marked left ventricular hypertrophy and systolic anterior motion of the mitral leaflets. On cardiac catheterization, a left ventricular peak systolic outflow gradient of 50 mm Hg was noted; this decreased to 10 mm Hg following intravenous administration of 100 mg of cibenzoline. It is imperative to recognize the existence of cases with Fabry’s disease associated with left ventricular outflow obstruction.