Citations

This study attempts to bring into focus certain details which have not been described adequately in textbooks of anatomy. This information is now of considerable significance because of its role in the genesis and surgical treatment of mitral stenosis. Variations in the size and shape of the mitral valve are described, with particular reference to the fact that valve commissures, or junctional zones between the leaflets, occur in the normal valve. Measurements of commissures, chordae tendineae and valve leaflets are presented, with a discussion of the significance of some of these measurements.

The spread of the excitatory process in the ventricular septum of the dog's heart has been studied in the isolated organ perfused by the Langendorff technic. It has been possible to remove large portions of the free wall of the right and left ventricles and explore the septal surfaces under direct vision. The mean excitatory pathway in the muscular mass of the dog's ventricular septum has been demonstrated to be from apex to base. The left side of the septum is activated before the right side, and the apical part of the right side is activated before its base.

The purpose of this investigation was to study the incidence and location of systemic arterial occlusion and pulmonary embolism in a consecutive series of cases of fatal acute myocardial infarction. Another consecutive series of cases in which healed myocardial infarction was demonstrated at necropsy was similarly studied. In none of the cases included in this study had anticoagulant therapy been employed. Massive pulmonary embolism was the most frequent fatal thrombo-embolic complication found among the cases of acute myocardial infarction. Cerebral infarction was the most frequent fatal thrombo-embolic complication found among the cases of healed myocardial infarction. Cerebral infarction was the most frequent fatal systemic arterial thrombo-embolic lesion in both groups. Acute splenic and renal infarcts were frequently demonstrated but with one exception appeared to play an incidental role in the clinical course of the patients. Although systemic arterial occlusion was frequently found in association with intracardiac mural thrombi, there were many other cases in which evidence of systemic arterial occlusion was found in the absence of intracardiac mural thrombi. A positive correlation existed between the presence of pulmonary and systemic arterial occlusion and the occurrence of congestive cardiac failure.

The successful treatment of essential hypertension remains one of the most difficult problems in medicine. Approximately 18 years have elapsed since extensive sympathectomy was first performed for essential hypertension. Extensive sympathectomy occasionally produces striking decrease in blood pressure of patients with essential hypertension; in many instances it fails to decrease blood pressure or modify the course of the disease. That which is most desired are some standards for preoperative selection of patients so that only patients who will be benefited by sympathectomy will be operated on. Unfortunately this apparently cannot be accomplished. The indications for sympathectomy remain at least partially uncertain and there is no agreement among those most experienced in the field of hypertension relative to the results of operation. There also are differences of opinion about the extensiveness of sympathectomy which is advisable. This paper indicates clearly differences of opinion among those most experienced in this field and emphasizes some of the points of agreement. It seems clear that additional technics of sympathectomy cannot be devised for the treatment of essential hypertension. There seems little doubt that sympathectomy would not be performed were adequate medical treatment available. This presentation gives the opinion of internists and surgeons who are particularly interested in hypertension and its treatment.

This is a study of the location and incidence of intracardiac thrombi in acute and in healed myocardial infarction. In myocardial infarction intracardiac thrombi occur predominantly in the left ventricle. Anterior myocardial infarcts are more commonly associated with mural thrombi than posterior myocardial infarcts. Large myocardial infarcts and congestive failure are factors which predispose to the formation of left ventricular mural thrombi in myocardial infarction.

A comparison was made of the circulatory effects of l -epinephrine and l -norepinephrine when various doses were given either intravenously or intra-arterially into anesthetized animals. No significant difference was found between the effects of identical doses of the two drugs on the arterial blood pressure, heart rate and blood flow. The intensity and duration of effect of either drug varied roughly with the dose given.

Solutions of Dextran Ph, Plasmoid, Periston and isotonic saline were compared with serum albumin and whole blood to determine the efficacy of the former as blood substitutes. Rats, guinea pigs and dogs were used as experimental animals. Dextran Ph, Plasmoid and Periston were found to be less satisfactory than whole blood, since 50 to 80 per cent of the rats and guinea pigs survived following their use compared with 100 per cent survival when whole blood was given. There was, however, 100 per cent mortality of the animals when a blood substitute was not given.

The successful use of dicumarol in the prevention of intravascular thrombosis and subsequent embolism has led to the investigation of other coumarin compounds as therapeutic anticoagulants. 4-Hydroxycoumain anticoagulant No. 63 is such a compound. Like dicumarol, it induces hypoprothrombinemia and daily tests of prothrombin time are necessary as a guide to dosage. Our experience indicates that a less fluctuating and somewhat more consistent therapeutic hypoprothrombinemia can be established and maintained with anticoagulant No. 63 than with dicumarol. The potential disadvantage of the prolonged hypoprothrombinemia after administration is stopped is counter balanced by the strong and relatively rapid antagonistic effect of vitamin K 1 .

Heparin administered intravenously increases the translucence of plasma during alimentary lipemia. This apparently is solely a physical change. This article reports observations concerning this phenomenon in normal persons and atherosclerotic patients. For purposes of maximal sensitivity, exceedingly small amounts of heparin are used, and distinct differences between the normal and the atherosclerotic individuals are noted, with the atherosclerotic failing to clear well on the same empiric dose of heparin as the normal persons. An unexpected observation was that the normal men developed a significantly greater degree of lipemia than did normal women after ingestion of the same fat meal.

The anticoagulant drugs, heparin and dicumarol, have been of great value in the prevrention and treatment of peripheral thromboembolic disease. The use of both drugs requires individualization of dosage based on the results of the appropriate tests of their effect on coagulation. The risk of bleeding is very small if heparin and dicumarol are properly used. New anticoagulant drugs are being studied and evaluated clinically in an effort to increase even further the effectiveness and safety of anticoagulant therapy.