Distribution of specific substance P binding sites in the heart and adjacent great vessels of the Wistar white rat.

Magnesium(Mg)-deficiency, whether dietary or an effect of a clinical condition such as diabetes, results in a variety of cardiovascular pathologies. Substance P (SP) has been implicated in the induction of cardiac focal inflammatory lesions that occur during Mg-deficiency. Blockade of SP receptors results in a significant reduction in the incidence of lesion formation. In an effort to identify potential endogenous cell populations of the heart, which may play a role in SP-dependent lesion formation, film- and light-microscopic autoradiography were used to map the distribution of specific SP binding sites in frozen sections of the normal rat heart and adjacent great vessels. Binding was assessed with 0.1 nM I-125 Bolton-Hunter labelled SP in the absence (total binding) or presence (non-specific binding) of excess unlabelled SP, prolactin, or L-703,606, a non-peptide antagonist of SP receptors. Film autoradiograms revealed prominent small foci of intense autoradiographic reactions dispersed intermittently around the periphery of the great vessels and coronary arteries, among the interstitial connective tissue of the heart, and along the cusps of the cardiac valves. Excess unlabelled SP caused a significant reduction (97.7% displacement; P < 0.001) in the focal autoradiographic reactions. L-703,606 caused a similar reduction in SP binding (97.3% displacement; P < 0.001), while prolactin had no statistically significant effect on the binding of radiolabelled SP. Light-microscopic autoradiograms revealed that the SP binding sites occurred within clusters of connective tissue cells or in rarely observed parasympathetic ganglia. No evidence was found to suggest the presence of SP receptors on endothelial cells, cardiac muscle fibers, or smooth muscle fibers. The connective tissue cells which bound SP within the heart will likely include types that are susceptible to SP activation and thus may play a role in initiation of the focal inflammation characteristic of Mg-deficiency.

An unusual case of Budd-Chiari syndrome--a case report.

The authors report a rare case of congenital Budd-Chiari syndrome in a twenty-eight-year-old male mongoloid. The patient was submitted to azygous-portal disconnection, because of the syndrome of portal hypertension supposedly due to cirrhosis of the liver. He died of hemorrhage of the liver on the third postoperative day. Autopsy revealed a congenital fibrotic obstruction of all suprahepatic veins, with a wide, round ligament containing a functional umbilical vein, which had been routinely ligated during surgery. An extensive review of the literature showed no similar report. The authors speculate that the inadvertent interruption of the round ligament, which until then had served as a pathway for venous draining of the liver, followed by ligation of the anastomoses between the portal and azygous systems, was the factor that triggered the lethal outcome. Thus, this appears to be the first case of congenital Budd-Chiari syndrome predominantly maintained at the expense of the round ligament of the liver, with a patent vascular branch.

Electrocardiographic changes in T. cruzi-infected rats after the ajmaline test.

Fifty-eight chronically T. cruzi-infected rats and 26 control rats were submitted to the ajmaline test (1 mg/kg, i.v. during ECG monitoring) after obtaining the resting ECG. Abnormal ECG tracings were detected in the resting ECG of 26 (44%) infected rats. After ajmaline injection, a decrease in heart rate was observed in control but not in infected rats. P wave enlargement, lengthening of the QRS complex, and increase of the PR as well as the QaT intervals were detected in all animals. Ajmaline induced right axis deviation in 7% of the control rats and left axis deviation in 26% of the controls, as well as in 23% of the T. cruzi-infected rats with abnormal resting ECG. However, after ajmaline injection, 7 (21%) of the 32 infected rats having normal resting ECG presented the following ECG changes not observed in control animals: indeterminate axis (15%), marked increase in PR interval and bizarre QRS complex (3%), and marked decrease in heart rate plus a significant increase in PR interval. These data show that ajmaline induces important ECG changes not only in controls, but also in T. cruzi-infected rats. Furthermore, since severe ECG changes occurred only in T. cruzi-infected rats having normal resting ECG, the ajmaline test can be used to unmask cardiac lesions in experimental chronic Chagas' disease.

Chronic Chagas' heart disease in children and adolescents: a clinicopathologic study.

A retrospective study of the medical records filed at the University Hospital from 1965 to 1983 and of 18456 autopsies carried out in the Department of Pathology of this Institution from 1953 to 1983, referring to patients aged less than 18 years was performed in an attempt to fully characterize chronic Chagas' heart disease in children and adolescents. Only 19 of these patients fulfilled the criteria for inclusion in the present study (12 cases with only clinical information and 7 cases with clinical and pathological information). We noted that the clinical manifestations of chronic Chagas' heart disease are congestive heart failure, thromboembolism and sudden death. Radiologic, electrocardiographic and anatomo-pathological findings demonstrated serious myocardial involvement. This set of alterations is also detected in adults with chronic Chagas' heart disease. Among adolescents, however, the disease exhibits relevant peculiarities such as rapid evolution to death within a short period of time (128 days), diagnostic difficulty related to the presence of significant mitral regurgitation (61% erroneous initial diagnosis), and low frequency of right bundle branch block (11% of cases). These findings suggest that among children and adolescents, chronic Chagas' heart disease may be of a peculiar type and therefore may be useful to clarify the pathogenetic mechanism of the disease.

Congenital absence of the circumflex coronary artery associated with dilated cardiomyopathy.

We report the first autopsied case of congenital absence of the left circumflex coronary artery. The patient was a 12-year-old girl in whom the clinical diagnosis was idiopathic dilated cardiomyopathy. This type of heart disease is uncommon among children. The coexistence of the two conditions therefore suggests a possible aetiologic relationship between them. The pathological findings, however, do not support such an association. Rather, they suggest that they co-exist by chance.

Cardiac thrombosis and thromboembolism in chronic Chagas' heart disease.

A retrospective study of Chagas' heart disease was carried out by a review of 1,345 autopsy reports, with special reference to cardiac thrombus and thromboembolic phenomena. The incidence of cardiac thrombus was higher in cases of heart failure (36%) than in cases of sudden death (15%), higher in heavier hearts, and unrelated to age or sex. The left- and right-sided cardiac chambers were equally affected by thrombus. Endocarditis and blood stasis were considered important factors in the pathogenesis of cardiac thrombus. Thromboembolic phenomena were more common in the systemic circulation but caused relatively more deaths by pulmonary embolism. Fourteen percent of patients with thromboembolic phenomena died from them. Patients with multiple thromboembolic phenomena had a higher risk of death from embolism. Cardiac thrombosis or thromboembolic phenomena, or both, were present in 44% of the cases studied. Prophylactic measures should be taken for these important complications of Chagas' heart disease.