Clinical recognition and surgical management of acute disruption of the mitral valve

Images

Atrial septal defect and calcification of the tricuspid valve

A patient with atrial septal defect and calcification of the tricuspid valve is presented. The calcification was first detected by fluoroscopy and its presence was confirmed during cardiac surgery. To our knowledge, this combination has not been reported previously. Possible factors contributing to the calcification are ageing, excessive blood flow, and raised right ventricular pressure.

Cerebral symptoms in pulmonary arteriovenous fistula. A result of paradoxical emboli (?)

Two cases of pulmonary arteriovenous fistulas with hemiparesis and other neurologic findings, possibly from paradoxical embolization, are described. Many theories have been put forward to explain the pathophysiology of the frequently present neurologic manifestations. We regard paradoxical embolization through the fistula as the most important factor in the pathogenesis of the neurologic deficit.

Due to the potential hazard of paradoxical cerebral embolization and possible subsequent brain abscess formation, surgical resection of all pulmonary arteriovenous fistulas wherever feasible is recommended.

Recurrent left atrial myxoma. Report of a case

Recurrence of a left atrial myxoma 6 years after the initial resection is reported. This, to our knowledge, is the second such case, and it emphasizes the need for a complete resection of the underlying atrial septum or atrial wall in cases of myxoma.

The measurement of digitoxin in human serum by radioimmunoassay

A sensitive, specific, and relatively simple immunoassay permitting measurement of pharmacological levels of digitoxin in human serum has been developed. The assay involves binding of (125)I-labeled tyrosine-digitoxigenin (specific activity > 400 mc/mg) by rabbit antibody to digitoxin. Antibody-bound radioactivity is precipitated by addition of a second antibody (goat anti-rabbit gamma globulin), and precipitate radioactivity is measured. Unlabeled digitoxin can be determined by the extent to which it competes with (125)I-labeled digitoxigenin and thus reduces precipitation of radioactivity. Before the assay, unlabeled digitoxin is extracted from serum with chloroform, and the chloroform solution is evaporated to dryness. Quantitation is accomplished by reference to a standard curve in which known amounts of digitoxin are added to normal serum. As little as 1 mmug of digitoxin per ml of serum produces significant reduction in precipitate radioactivity. The sera of 5 patients were analyzed before and after digitalization. A highly significant reduction in precipitate counts in the postdigitalization sera was observed (P < 0.001). Serum digitalis levels were measured in 19 patients receiving no digitalis and in 19 patients taking digitoxin or digitalis leaf. Little of no digitalis-like activity was detected in control sera, whereas serum levels averaged 27 mmug/ml in those on digitalis (range 4-60 mmug/ml, P < 0.001). Patients judged clinically to show digitals toxicity in general had higher levels than those without signs of toxicity. Patients receiving digoxin had little or no detectable digitalis in their serum with this method. In addition to the assay itself, other potential uses of the antidigitalis antibody include treatment of digitalis toxicity and studies on the tissue localization of digitalis.