bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Breathing Carbon Dioxide upon the Pulmonary Circulation
Authors: FISHMAN ALFRED P. , FRITTS HARRY W. , COURNAND ANDRÉ
Published: June 2012

The effects of inhaling 5 per cent carbon dioxide in air on the pulmonary arterial blood pressure and flow were studied in 5 subjects with normal pulmonary circulations and in 10 patients with chronic pulmonary emphysema.

In the 5 control subjects, with an average increase in arterial P

CO
CO2

of 6 mm. Hg (37 to 43) and a 3-fold increase in minute ventilation, both pulmonary arterial blood pressure and flow remained unchanged. In the 10 patients with chronic pulmonary emphysema with a similar increase in arterial P

CO
CO2

(45 to 52) and a 2-fold increase in minute ventilation, there was a 14 per cent increase in cardiac output and a rise in pulmonary arterial mean pressure of 4 mm. Hg. In these patients an increment in pulmonary arterial pressure was invariably associated with an appreciable increment in blood flow.

The present study affords no support for the view that the breathing of air enriched with carbon dioxide elicits pulmonary vasoconstriction in either normal subjects or in patients with chronic pulmonary disease.
Pathologic Physiology of Angina Pectoris and Acute Myocardial Infarction
Authors: BLUMGART HERRMAN L. , ZOLL PAUL M.
Published: June 2012

Some of the unique physiologic characteristics of the coronary circulation have been pointed out. In the normal heart, the coronary arteries are
functionally
end arteries. Watery injections, however, reveal anatomic fine anastomotic communications between the coronary arteries measuring less than 40 µ. But they are of limited functional significance in obviating the untoward effects of sudden coronary narrowing or occlusion. Complete occlusion or considerable narrowing of one or more coronary arteries may exist without giving rise to any clinical signs or symptoms and without having produced myocardial damage. The apparent inconsistency between the presence of long-standing obstructive arterial lesions and the absence of significant pathologic or clinical evidence of myocardial damage is dispelled by the demonstration of a collateral circulation which serves as a bypass in relation to the obstruction in each of these hearts. The pathologic and physiologic substrates of angina pectoris, coronary failure, and acute myocardial infarction have been discussed.
Dissecting Aneurysm of the Aorta The Clinical Features of Thirty Autopsied Cases
Authors: ERB BLAIR D. , TULLIS I. FRANK
Published: June 2012

The clinical diagnosis of dissecting aneurysm of the aorta depends on awareness of the entity, keen clinical suspicion, and an understanding of the varied manifestations. Clinical suspicion is sharpened by association of certain preexisting conditions found to be related to an increased incidence of aortic dissection. Recognition of the Marfan's syndrome, pregnancy, or preexisting hypertension in a patient presenting as an acute catastrophe may lead to the diagnosis. A family history of aortic dissection is similarly helpful.

The variable manifestations call for careful reasoning. Multiple system involvement in many cases is the initial lead in establishing the diagnosis. The many systems frequently involved in the symptomatology of aortic dissection have in common the origin of the blood supply. When the aorta is damaged, branches to various organs may be affected so that the symptoms depend on the branches involved. Because any portion of the aorta may be involved in the dissecting process, no single clinical picture suffices for its recognition. Aortic valvular findings often are seen with involvement of the ascending aorta, central neurologic findings may result from occlusion of the carotid arteries, spinal cord manifestations may result from occlusion of the intercostal arteries, renal manifestations may be seen with renal artery involvement, and so on down the aorta. However, the pattern of a catastrophic episode—whether cardiovascular, neurologic, or abdominal—calls for consideration of aortic dissection. All of the finesse of the most careful physical examination may be required to make the diagnosis but the coexistence of chest pain, aortic murmurs, and peripheral artery occlusion is practically diagnostic. Laboratory adjuncts including roentgenographic evidence of mediastinal widening, evidence of hematuria, and the absence of electrocardiographic evidence of myocardial infarction may be helpful. Electrocardiographic evidence suggestive of myocardial infarction does not, however, exclude aortic dissection.

Dissecting aneurysm of the aorta now is a surgical emergency that requires early accurate diagnosis and early surgical treatment, if the natural survival rate of 10 per cent is to be improved.
Pulmonic Stenosis, Ventricular Septal Defect, and Right Ventricular Pressure above Systemic Level
Authors: HOFFMAN J. I. E. , RUDOLPH ABRAHAM M. , NADAS ALEXANDER S. , GROSS ROBERT E.
Published: June 2012

Ten patients with pulmonic stenosis are reported who, despite having right ventricular systolic pressures much above systemic levels, had ventricular septal defects proved at operation in 9 and suggested by indicator-dilution curves in the other.

Because of the high right ventricular systolic pressures these patients had clinical and electrocardiographic evidence of marked right ventricular hypertrophy and were initially thought to have severe pulmonic stenosis with an intact ventricular septum.

One patient had an almost single ventricle with pulmonic and aortic stenosis.

In all the others the right ventricular systolic pressure failed to equilibrate with pressures in the systemic circulation. In 2 patients this was probably due to obstruction of the ventricular septal defect by the septal leaflet of the tricuspid valve. In the others the suggestion that the ventricular septal defect was closed off during systole by muscular contraction was confirmed in 1 patient at operation.

This syndrome has been reported in other series and may occur in as many as 5 to 10 per cent of patients diagnosed as having severe pulmonic stenosis.

It is important to know before operation whether or not there is a ventricular septal defect associated with the pulmonic stenosis, for this influences the decision about doing a right ventriculotomy.

The preoperative diagnosis of this variant of tetralogy of Fallot may be made by phonocardiography and cardiac catheterization.
Heart Block after Repair of Ventricular Septal Defect in Children
Authors: LAUER RONALD M. , ONGLEY PATRICK A. , DUSHANE JAMES W. , KIRKLIN JOHN W.
Published: June 2012

From March 1955 to April 1959, 174 patients with ventricular septal defect and 124 patients with ventricular septal defect associated with pulmonic stenosis were referred from the Section of Pediatrics of the Mayo Clinic for open intracardiac repair.

Forty-eight of these 298 patients had complete heart block at some time following operation. Eighteen of the patients with heart block died in the immediate postoperative period, 18 had reversion to normal sinus rhythm, and 12 were discharged from the hospital with complete heart block. Three of these 12 patients died subsequently. Two died presumably as a direct result of complete heart block and a third died following a second open cardiac operation. Of the 9 surviving patients, 3 have had serious bradycardia or periods of asystole and 6 have no symptoms from heart block.

One of 3 surgical technics was employed for all the patients in this study with variation in incidence of block with the use of each technic. Other factors that might relate to the incidence of heart block are discussed.

The management of the patient with complete heart block both in the immediate post-operative period and after dismissal from the hospital is described.
Central Circulatory Changes Accompanying Mitral Commissurotomy
Authors: RICHMAN HAROLD G. , LONG J. BRADLEY , RAPAPORT ELLIOT
Published: June 2012

The flow-pressure relationships within the pulmonary circuit and left side of the heart were measured in 24 patients immediately before and just after mitral commissurotomy. The diastolic pressure gradient across the mitral valve was decreased in all cases, but was rarely obliterated completely. No significant change occurred in cardiac output; a shorter ventricular filling period and a consequent increase in mitral valve flow per unit of filling time was consistently observed. A decrease in mean pulmonary artery pressure generally occurred with valve fracture, but it was almost always less than the decrease in left atrial pressure. The result was an immediate postoperative increase in the pressure gradient and in the calculated resistance across the pulmonary circuit. These observations suggest that the reduction in left atrial pressure following mitral commissurotomy has no immediate effect on pulmonary vasomotor tone.
Studies of Peripheral Circulation during Sickle-Cell Crisis
Authors: MANFREDI FELICE , SPOTO ANGELO P. , SALTZMAN HERBERT A. , SIEKER HERBERT O.
Published: June 2012

In 18 Negro patients with sickle-cell anemia or sickle cell-hemoglobin C disease, gradients of oxygen and pH were measured between brachial artery and superficial and deep venous system of the upper extremity. The results obtained during crisis were compared with those obtained from asymptomatic patients.

Arterial oxygen unsaturation, with normal arteriovenous gradients for oxygen and pH was observed in the 11 asymptomatic patients. Unusually low arteriovenous gradients for oxygen and pH, mainly due to abnormal venous values, were found when blood draining from cutaneous areas was compared with arterial samples in the 7 patients studied during acute crisis. The 5 patients restudied after symptoms subsided showed a return toward normal of arteriovenous differences.

The evidence suggests that during crisis arterialization of venous blood is the result of anatomic or functional by passes in the superficial circulation, so that oxygen is not removed by the tissues. It is postulated that a vascular neurogenic mechanism may be the precipitating factor in sickle-cell crisis.

It is also suggested that a low arteriovenous oxygen gradient or arterialization of superficial vein blood may be used as a laboratory aid in establishing the diagnosis of sickle-cell crisis in uncertain cases.
The Clinical Pattern in Certain Types of Occlusive Cerebrovascular Disease
Authors: MILLIKAN CLARK H. , SIEKERT ROBERT G. , WHISNANT JACK P.
Published: June 2012

This has been a summary of the clinical patterns in certain types of cerebrovascular disease with emphasis on occlusive disease. Knowledge concerning these categories is important in studying the results of various therapeutic technics and in selecting the correct treatment for some subdivisions where effective therapy exists.
Congenital Familial Nodal Rhythm
Authors: BACOS JAMES M. , EAGAN JOHN T. , ORGAIN EDWARD S.
Published: June 2012

An unusual family group covering 3 generations is presented, all of whose members manifest a characteristic arrhythmia that appears to be an inherited trait. Each of the 9 known descendants exhibits a nodal bradycardia and each of the 4 descendants who have entered the fourth decade of life have also experienced paroxysms of atrial fibrillation. These paroxysms almost invariably terminate with the re-establishment of nodal rhythm. By history, the majority of these individuals are asymptomatic, and detailed examination of 2 adult members has failed to uncover evidence of specific cardiac disease. The problem of familial arrhythmia is briefly reviewed.
Spontaneous Closure of Ventricular Septal Defects
Authors: EVANS J. R. , ROWE R. D. , KEITH J. D.
Published: June 2012

A group of 37 children is described in whom a systolic murmur heard early in life gradually diminished and eventually disappeared. When the patients were first seen, the clinical findings suggested a small ventricular septal defect but no thrill was present and the systolic murmur had a superficial blowing quality with high-frequency vibrations and tended to stop before the second heart sound. Cardiac catheterization demonstrated a small left-to-right shunt at ventricular level in 4 of the patients while the murmur was present; in 1 this was repeated after the murmur had gone and no abnormality could be demonstrated.

Cardiac catheterization in other patients with typical disappearing systolic murmurs showed a left-to-right shunt in some but in others this was too small to be detected by routine oxygen studies. A rough correlation was established between the length and intensity of the murmur and the size of the shunt. With angiocardiography and intracardiac phonocardiography the exact site of the ventricular septal defect was localized to the muscular portion of the septum in 4 of the patients.

In 1 patient who presented with congestive heart failure, clinical and hemodynamic findings of a large ventricular septal defect diminished over several years and finally disappeared.

Children with the specific type of systolic murmur described may be recognized as having a small defect in the muscular ventricular septum. The defect is thought to be gradually reduced in size and ultimately closed by hypertrophy of septal muscle. Spontaneous closure appears to be not uncommon with small ventricular septal defects and may rarely occur with lesions large enough to present with congestive heart failure.
Comparative Studies of Protoveratrine A and Protoveratrine B Intravenously in Hypertensive Man
Authors: WINER BERTRAM M.
Published: June 2012

Comparative studies of intravenously administered protoveratrine A and protoveratrine B in hypertensive man indicate that the alkaloids have qualitatively similar hypotensive, bradycrotic, and emetic actions, but quantitatively different hypotensive and emetic potency. The relative hypotensive potencies of the two substances were determined by analyses of logarithmic dose-response curves in the same patients. On a weight basis protoveratrine B was slightly less potent than protoveratrine A.

A favorable dissociation between hypotensive and emetic activity was found. Tolerance ratios were determined in which the largest doses of protoveratrine B given without nausea were compared with the doses of protoveratrine A producing nausea. These ratios were adjusted for the differences in hypotensive potency of the alkaloids. Protoveratrine B was better tolerated than protoveratrine A (
p
<.001). Indeed, protoveratrine B had little emetic activity when given intravenously in doses producing normotension. Protoveratrine B appears to have properties that warrant its preferential selection for parenteral administration. Its effective dosage range has been studied.

The strong hypotensive activity of intravenously administered protoveratrine B, its development of maximal action within minutes, and its pulse-slowing effect favor its use in those hypertensive states in which almost immediate lowering of the blood pressure is indicated.

Fixed hypertension lends itself to the application of biological assay technics. The use of such technics in human pharmacology fosters the perception of clinically significant differences among drugs that are chemically closely related.
The Direct Effects of Norepinephrine, Epinephrine, and Methoxamine on Myocardial Contractile Force in Man
Authors: GOLDBERG LEON I. , BLOODWELL ROBERT D. , BRAUNWALD EUGENE , MORROW ANDREW G.
Published: June 2012

The effects of 5 sympathomimetic amines on myocardial contractile force were determined with the Walton-Brodie strain-gage arch in 16 patients undergoing operations for congenital heart disease. Equal doses of norepinephrine and epinephrine produced almost identical increments in myocardial contractile force; equipressor doses of methoxamine resulted in little or no change in the force of contraction. Mephentermine and metaraminol produced increments in myocardial contractile force similar to those following norepinephrine administration but the duration of action was longer. The results of these studies indicate that there are no qualitative differences in the actions of these amines on cardiac contractile force of dog and man and provide a basis for the rational clinical use of these agents.
Precordial Scanning
Authors: CORNELL WILLIAM P. , BRAUNWALD EUGENE , MORROW ANDREW G.
Published: June 2012

A precordial scanning technic and its application in the detection of left-to-right cardiac shunts in 75 patients are described. I
131
-labeled Diodrast was injected into an antecubital vein, its concentration in the central circulation was metered by means of a scintillation detector, and the time-concentration curve were recorded directly. In patients with left-to-right shunts these curves were modified in a characteristic fashion; the build-up time was normal, but the disappearance of isotope from the central circulation was slow. The product of the build-up time and disappearance rate was generally lower than in patients without cardiac shunts. The clinical value of this simple technic in detecting or excluding the presence of left-to-right shunts is discussed.
An Electrocardiographic Pattern Associated with Mitral Valve Deformity in Marfan's Syndrome
Authors: BOWERS DORRANCE
Published: June 2012

A collected series of 5 patients with Marfan's syndrome is reported in whom S-T depression and T-wave inversion in electrocardiographic leads II, III, and aV
F
were associated with necropsy-proved deformity of the mitral valve.
An Appraisal of the Double Indicator-Dilution Method for the Estimation of Mitral Regurgitation in Human Subjects
Authors: WILSON WILLIAM S. , BRANDT RALPH L. , JUDGE RICHARD D. , MORRIS JOE D. , CLIFFORD MARY E.
Published: June 2012

The amount of mitral regurgitation was estimated in 50 patients by an indicator-dilution technic and by the usual clinical, catheterization, operative, and autopsy criteria. There was a good correlation between the two estimates. Patients with significant mitral regurgitation (grade 2 or grade 3) had, with one exception,
Q

R

/
Q

F

ratios above 0.41. There were at least two instances where the calculated
Q

R

/
Q

F

was almost certainly falsely high. It seems likely that these discrepancies are related to the presence of an unusually large volume between the pulmonary artery and the femoral artery.
Tomographic Evaluation of Hemodynamic Changes in Mitral Stenosis
Authors: DULFANO M. J. , ADLER H.
Published: June 2012

The hemodynamic findings in 31 patients with mitral valvular disease were correlated with the signs obtained by chest tomography. The normal and pathologic findings are described. The advantages of the tomographic technic for the study of the pulmonary vasculature are pointed out.

The progression of mitral valve narrowing was considered to be best related to the integrated picture of "impaired venous drainage." On this basis, three stages were defined.

The over-all response of the pulmonary circulation to the severity of the disease can be judged by the pattern of blood vessels filling throughout the lung.

It is concluded that for the evaluation of mitral valvular disease routine tomographic technic can indicate many of the essential hemodynamic findings with less hazard than either angiography or cardiac catheterization.
Glycogen-Storage Disease
Authors: MULLER OTTO F. , BELLET SAMUEL , ERTRUGRUL ALI
Published: June 2012

A case of glycogen-storage disease (Coritype II), with accumulation of glycogen in the myocardium, skeletal muscle, smooth muscle, liver, kidney, central nervous system, and autonomic ganglia is presented.

Glycogen storage in the autonomic ganglia of the intestinal tract (Plexus-myentericus-Auerbach), which gave rise clinically to Hirschsprung's disease, could explain the feeding problems and constipation often observed in these cases.

The classification into four different types of Cori and Andersen appears to be the most satisfactory one at the present time. These types are different disease entities with the same expression of abnormality, the deposition of glycogen; but the pathogenesis and the clinical and pathologic findings are strikingly different.

Glycogen storage of the heart is probably more common than the review of the literature indicates. Many of these cases are missed, mainly types III and IV, because the possibility is not considered and the patient is inadequately studied in life and during necropsy.
Acute Hemorrhage and Necrosis of the Intestines Associated with Digitalization
Authors: GAZES PETER C. , HOLMES CHARLES R. , MOSELEY VINCE , PRATT-THOMAS H. RAWLING
Published: June 2012

Eleven cases with acute hemorrhage and necrosis of the bowel are described. In all cases there was high dosage of digitalis and definite toxicity in seven. Digitalis was considered as the main associated factor, especially since there was no mesenteric arterial involvement and, in four cases, there was no congestive failure at autopsy. Hepatic vein or sinusoidal sphincter constriction with resulting portal splanchnic venous congestion was considered as possible mechanisms by which digitalization produced this syndrome.
Studies on Digitalis
Authors: FRYE ROBERT L. , BRAUNWALD EUGENE
Published: June 2012

The effects of triiodothyronine (T
3
) administration on digitalis requirements was studied in a group of patients with atrial fibrillation. The ventricular rate was utilized to provide a quantitative expression of digitalis effect. In one patient the amount of acetylstrophanthidin, administered as a constant infusion, required to slow the ventricular rate to 70 beats per minute rose from an average of 0.58 mg. while he was myxedematous, to 1.50 mg. when he was euthyroid. When mild thyrotoxicosis was induced in three euthyroid patients the daily dose of digoxin had to be increased approximately four-fold in order to maintain the ventricular rate at a control level. In three patients it was observed that reserpine or syrosingopine administered intramuscularly abolished the increased requirements for digoxin induced by T
3
. In two patients syrosingopine was found to prevent partially the tachycardia resulting from large doses of intravenous T
3
. The possible mechanisms responsible for these effects and their therapeutic implications are discussed.
Primary Myocardial Disease
Authors: FOWLER NOBLE O. , GUERON MOSCHE , ROWLANDS DAVID T.
Published: June 2012

This study describes 18 patients from the University of Cincinnati Hospitals who died of congestive heart failure without clinical or pathologic evidence of a primary cause.

Clinical features. Their ages were from 18 months to 68 years at death. Fourteen were male and four female; 11 were white and seven were Negro. Seven patients had heart failure for 5 years or more; three had heart failure for over 10 years. Seven patients were alcoholic and three had nutritional cirrhosis. Transient mitral or tricuspid systolic murmurs and apical protodiastolic gallop rhythms were common. Atrial fibrillation was present in six patients. The electrocardiograms revealed abnormal left axis deviation in three and left bundle-branch block in two.

Right heart catheterization was performed in four of these patients and showed low cardiac output, increased arteriovenous oxygen difference, and elevation of pulmonary arterial, pulmonary wedge, right ventricular diastolic, and right atrial pressures.

Pathologic features. Heart weights were over 500 Gm. in 13 patients; all 18 had left ventricular hypertrophy. Mural thrombi were present in 10; six had pulmonary emboli and three had systemic arterial emboli. One patient had gross myocardial scarring; only two had small accumulations of inflammatory cells in the myocardium. Ten had focal increase of elastic tissue.

Primary myocardial disease may simulate coronary artery disease because of the abnormal electrocardiogram; it may simulate hypertensive heart disease because of elevation of diastolic blood pressure during heart failure in some patients; it may simulate pericardial effusion because of the poor cardiac pulsations, narrow pulse pressure, and paradoxical pulse. It may simulate rheumatic heart disease because of the apical systolic and diastolic murmurs, left atrial enlargement, and presence of Kerley lines. The cause is unknown. Only one patient in this group had a familial history of similar heart disease.
Plasma Heparin Levels
Authors: ENGELBERG H.
Published: June 2012

Endogenous plasma heparin was determined in 147 males and 113 females. Serum cholesterol was measured in the entire group, and low-density lipoproteins were ultracentrifugally analyzed in 131 males aud 77 females.

Statistical analysis of the data showed a definitely significant (
p
<.01) negative correlation between heparin on the one hand and serum cholesterol and Sf 12-400 lipoproteins on the other in males.

In females the correlation between heparin and cholesterol was negative but fell short of the 5 per cent level of significance. The correlation between heparin and Sf 12-400 lipoproteins was negative and statistically definitely significant (
p
<.01). The correlation with the Sf 0-12 lipoproteins was also negative and probably significant (
p
<.05).

These results afford substantial evidence that a relative deficiency of circulating heparin rin is one of the important causative factors leading to elevated levels of serum lipid.
The Mechanical Consequences of Anomalous Atrioventricular Excitation (WPW Syndrome)
Authors: MARCH HAROLD W. , SELZER ARTHUR , HULTGREN HERBERT N.
Published: June 2012

The mechanical consequences of anomalous atrioventricular excitation were studied in 12 patients by means of phonocardiograms, carotid pulse tracings, and in one instance, by data from cardiac catheterization. Three of these patients were also observed during normal conditions so that they supplied their own control data.

In five instances mechanical anomalies were detectable as a consequence of the electrocardiographic abnormality. These anomalies were complex and consisted in one case of early onset and completion of ejection on both sides, and in another case of early completion on the left side. In three instances there was late activation on the contralateral side and possibly on the homolateral side as well.

The remaining cases exhibited no such abnormalities by the methods studied, and in one subject this is illustrated with records made during both anomalous and normal conduction.

The literature pertaining to this problem is critically reviewed, and an attempt is made to interpret both the previous and the present observations. The divergent nature of the observations suggests that the effect of anomalous excitation on the mechanics of the heart is the resultant of a number of variables, including the transmission time through the atrioventricular node and the site of entry of the anomalous focus.

It is possible that the atrioventricular node does not function in some cases in which Wolff-Parkinson-White conduction is always present and it is not possible to induce normal beats with drugs, exercise, or respiratory maneuvers.
Relationship between Arterial Pressure and Negative U Waves in Electrocardiograms
Authors: GEORGOPOULOS A. J. , PROUDFIT W. L. , PAGE IRVINE H.
Published: June 2012

Direct correlation exists between arterial pressure levels and negativity of U waves in electrocardiograms of hypertensive patients; lowering of arterial pressure results in conversion of negative to positive U waves in the majority of hypertensive patients. Presence of negative U waves does not necessarily indicate organic myocardial changes or a grave prognosis; when their polarity remains unchanged following antihypertensive treatment, it may indicate unsatisfactory control of arterial pressure.
Effects of Erythrol Tetranitrate and Amotriphene on Exercise Tolerance Tests in Angina Pectoris
Authors: RUSKIN ARTHUR
Published: June 2012

Sublingual erythrol tetranitrate is a potent drug in counteracting coronary insufficiency, as evidenced by reversal of positive electrocardiographic exercise tolerance tests in 72 per cent of 36 cases and reduction of anginal attacks in them by more than 50 per cent.

Comparative studies with amotriphene indicate some subjective alleviation of angina, but objective reversals of the electrocardiographic effects of exercise in only 16 per cent of the cases.

Side effects of erythrol tetranitrate, particularly headache, are seen in a minority of cases and are often circumvented by starting with a small dose and gradually increasing it as necessary.

Alleviation of ectopic beats on exercise occurred equally in a minority of cases on the two drugs.
The Pulmonary Arterial Tree in Atrial Septal Defect
Authors: WAGENVOORT C. A. , NEUFELD HENRY N. , DUSHANE JAMES W. , EDWARDS JESSE E. , Wagenvoort Noeke
Published: June 2012

The pulmonary vascular tree was studied in 12 cases of uncomplicated atrial septal defect in fetuses, infants, and children. The ages of these subjects ranged from 24 weeks of fetal life to 11 years. A quantitative analysis was made of the medial thickness and of the index of medial surface area (ratio of medial tissue to pulmonary parenchyma) of the pulmonary arterial branches. In contrast to subjects with ventricular septal defect in corresponding age groups, the three fetuses in this series had medial hypertrophy, as indicated by a high index of medial surface area. In the postnatal group, both the medial thickness and the index of medial surface area were also usually greater than in the controls of corresponding ages, notably in two patients, who, at the ages of 7 weeks and 4 months, died of cardiac failure. No satisfactory explanation for these unexpected findings can be offered.

Slight to moderate intimal proliferation was observed in some muscular and elastic pulmonary arteries, in bronchial arteries, and in pulmonary veins in several subjects. Thickening of the intima in elastic arteries was observed in a fetus of 26 weeks' gestation. Pronounced obliterative intimal changes were found in only one subject, an 11-year-old girl with severe pulmonary hypertension.
Blood Volume Changes in Cyanotic Congenital Heart Disease and Polycythemia Rubra Vera
Authors: VÉREL DAVID
Published: June 2012

The blood volume has been measured in 12 adult patients with cyanotic congenital heart disease and in 12 patients with polycythemia rubra vera by radioactive isotopes. In congenital heart disease the total blood volume was found to be within normal limits provided the red cell volume had not risen so high as to make an increase in total blood volume inevitable. In polycythemia rubra vera the total blood volume increased rapidly once a hematocrit level of 55 per cent had been exceeded. Increasing polycythemia in congenital heart disease was found to be associated with the predictable fall in plasma volume, and a formula for estimating the plasma volume from the predicted normal blood volume and the hematocrit is presented. It is suggested that the low plasma volume that may be found in very polycythemic patients may be partly responsible for their known tendency to postoperative hemorrhage.
A Guide to Anticoagulant Therapy
Authors: ALEXANDER BENJAMIN , WESSLER STANFORD
Published: June 2012

The physician who undertakes anticoagulant therapy tampers with one of the most important homeostatic functions of the body. In so doing, he subjects the patient to the calculated hazard of possible hemorrhage balanced against the risks of the thrombosis or embolism that he seeks to prevent or treat. Agents currently employed are heparin and coumarin-type compounds. These two categories of anticoagulants act at different sites of the coagulation mechanism, are administered differently, are metabolized differently, are reversed by different antidotes, and their effects are measured by different tests.

Certain facts about which the physician should be adequately informed have been presented regarding the hemostatic mechanism; the physiology and pharmacology of the anticoagulants, especially as they may explain the wide variation in individual response; certain aspects of methodology; and the various practical problems involved in therapeutic management. Emphasis has been placed on the importance of individualization of treatment, careful clinical observation, and frequent reliable laboratory tests as guides to proper therapy.
The Pulmonary Vessels in Incipient Left Ventricular Decompensation
Authors: SIMON MORRIS
Published: June 2012

Dilatation of the pulmonary vessels of the upper zones and constriction of the vessels of the lower zones characterizes left ventricular decompensation.

These changes may precede the onset of clinical symptoms providing a useful warning sign of impending danger.

A hypothesis is suggested to account for the non-uniform vessel pattern.

An exception is noted in patients with severe emphysema or bronchitis in whom generalized dilatation may occur.
Aneurysm of the Distal Popliteal Artery and Its Relationship to the Arcuate Popliteal Ligament
Authors: GEDGE STAFFORD W. , SPITTEL JOHN A. , IVINS JOHN C.
Published: June 2012

Two cases presenting complications of popliteal aneurysm requiring amputation have been presented. Dissection of these limbs showed proximal popliteal aneurysms located immediately beyond the adductor magnus tendinous hiatus and, in addition, distal popliteal aneurysms immediately below the arcuate popliteal ligament.

Another case is described in which bilateral popliteal aneurysms were located in the distal popliteal artery—that is, immediately below the arcuate popliteal ligament. These findings support the concept that post-stenotic dilation may be one of the causal factors in the pathogenesis not only of proximal but also of distal popliteal aneurysms.
Surgical Treatment of Dissecting Aneurysm of the Aorta Analysis of Seventy-Two Cases
Authors: DE BAKEY MICHAEL E. , HENLY WALTER S. , COOLEY DENTON A. , CRAWFORD E. STANLEY , MORRIS GEORGE C.
Published: June 2012

Dissecting aneurysm of the aorta is an extremely serious condition that pursues a rapidly fatal course in more than 75 per cent of cases. Follow-up data on 72 patients surgically treated indicate that effective surgical treatment significantly alters the course of the disease and in the majority of instances removes the threat of death by rupture. The operative mortality rate in these 72 patients was 26 per cent. For lesions occurring distal to the left subclavian artery, resection of the descending thoracic aorta with replacement by aortic graft utilizing hypothermia or the bypass pump was successful in 80 per cent of cases.

Most patients surviving operation have been able to resume previous activities with minimal risk of sudden death from rupture of the aneurysm or failure of the aortic graft.

The importance of recognizing the characteristic clinical manifestations, of making precise roentgenographic diagnosis, and of instituting effective surgical treatment in the management of dissecting aortic aneurysm has been stressed.
The ATPases of Muscle Proteins
Authors: Taggart John V. , MORALES MANUEL F. , WATANABE SHIZUO
Published: June 2012

The ideas and results of Blum, Oosawa, Strohman, and many others are reviewed and, when consolidated with the authors' work, lead to the following picture of muscle protein adenosine triphosphatases (ATPases). Two major features of myocin ATPase seem to be a catalytic interaction between enzyme, a metal cation, and the terminal pyrophosphate moiety of adenosine triphosphate (ATP) and a rate-retarding interaction between enzyme, Mg
++
, and the purine ring of ATP. Sulfhydryl groups of the enzyme participate at both loci. In the catalytic interaction an ionizable group (pK, ca. 6.8) may participate. G-actin molecules binding ATP (probably by the purine ring) and relieved of their mutual repulsion cooperate in catalysing dephosphorylation, thereby giving rise to the somewhat loose, possibly helical, structure of F-actin.
Muscle Physiology and Contraction Theories
Authors: Taggart John V. , PODOLSKY RICHARD J.
Published: June 2012

The structural basis of current contraction theories is the double array of thick and thin myofilaments revealed by the electron microscope. The physiologic properties that characterize the contractile process are natural consequences of this structure if (a) during shortening the 2 sets of filaments move relative to each other and (b) the flux of chemical energy through the contractile mechanism is limited by interaction between complementary sites distributed along the 2 sets of filaments. Contraction models fitted to these ideas differ largely in the mechanism by which force is generated. In the
sliding model
, force is developed by mechanical interaction between the thick and thin filaments, and filament length remains constant during contraction. In the
folding model
, force is developed in the thin filament, which shortens during contraction. Both models quantitatively account for the force-velocity relation and the Fenn effect. They also accommodate the quick-release phenomenon and predict, at least qualitatively, the isotonic velocity transients that can be seen after quick release from tetanic tension.
Some Aspects of Myogenesis in Vitro
Authors: Eichna Ludwig W. , KONIGSBERG IRWIN R.
Published: June 2012

Suspensions of embryonic chick leg muscle cells have been employed to establish replicate monolayer cultures. Such cultures grow rapidly to form a confluent layer of cells. Despite culture conditions generally assumed to be "dedifferentiative," a high degree of differentiation is attained in terms of the development of cross-striated myofibrils and contractility. To evaluate the possible role of in situ nuclear replication in the development of multinuclearity in muscle cells, an inhibitor of deoxyribonucleic acid (DNA) synthesis, methyl-bis (betachloroethylamine) (nitrogen mustard), was employed. Treatment with nitrogen mustard at concentration levels that profoundly inhibit DNA synthesis does not block the formation of multinuclear cells. On the basis of the pattern of nuclear enlargement after nitrogen mustard treatment, the cytologic picture of treated cultures is interpreted as indicating that the nuclei of only mononucleated cells are normally capable of proliferation. An absence of proliferative activity in the nuclei of multinuclear cell suggests that myoblast proliferation is self-limiting in this system and may explain, in part, the high degree of differentiation attained in monolayer culture.
Differentiation of the Atrioventricular Conducting System of the Heart
Authors: Eichna Ludwig W. , DEHAAN ROBERT L.
Published: June 2012

The structure and function of the atrioventricular conducting system of the heart, and its relationship to the myocardium, are examined from a developmental point of view. On the basis of information derived from electron micrographic, electrophysiologic, and developmental studies of heart tissue, it is concluded that: (1) The idea of the syncytial nature of the heart lacks a sound anatomic basis. (2) Cytodifferentiation during embryonic cardiogenesis results in the development of at least 2 distinct populations of cells: those comprising the bulk of the myocardium and a second type, the specialized cells of the conductive tissue, which differs in histology, biochemistry, and physiology. (3) The common view of the myocardium as a spontaneously active tissue may require revision, since several lines of evidence appear to indicate that myocardial cells are quiescent until stimulated by an extrinsic source. Under normal circumstances, this stimulus source is the conductive tissue.
Cardiac Myosin and Congestive Heart Failure in the Dog
Authors: Eichna Ludwig W. , OLSON ROBERT E. , ELLENBOGEN ERIC , IYENGAR RAJA
Published: June 2012

Chronic congestive heart failure has been produced in dogs by surgical induction of valvular disease. Cardiac myosin was isolated from the normal dogs and from dogs with congestive heart failure and characterized. Physicochemical properties of the cardiac myosins were determined by measurements of velocity sedimentation, partial specific volume, rate of diffusion, limiting viscosity number, light-scattering behavior, and ATPase activity. The measurements show that normal cardiac myosin (myosin C) has a molecular weight of 225,000, whereas myosin from the failing heart (myosin F) has a molecular weight of 690,000. This change in molecular weight occurs without a marked alteration in amino acid composition and suggests that end-to-end trimerization of normal cardiac myosin occurs in association with congestive heart failure in the dog. There was no significant change in ATPase activity.
Contractile Proteins of Heart Muscle in Man
Authors: Eichna Ludwig W. , BING RICHARD J. , KAKO K.
Published: June 2012

This report deals with the contractile proteins of human muscle in congestive failure, and with the role played by the contractile proteins and by biochemical processes in the regulation of the mechanical function of the heart. The contractility of actomyosin bands prepared from heart muscle of patients who had died in congestive failure was diminished as compared to those prepared from normal hearts. This may have been the result of defective protein synthesis. The increase in heart rate was correlated with the activity of phosphorylase a in heart muscle and with changes in carbohydrate intermediates (lactate, glucose-6-phosphate [G-6-P] and glycogen). The heart rates over 300 per minute were associated with a transient increase, followed by a decrease, in phosphorylase a activity; glycogen diminished, while lactate and G-6-P increased. The oxidation-reduction potential in heart muscle became more negative. In the absence of myocardial anoxia, the increased rate of stimulation of the heart produced no alterations in either the concentration of carbohydrate intermediates or the phosphorylase a activity. Alterations in function of the heart that come into play upon rapid changes of cardiac activity are the result of the integration of several diverse biochemical cellular reactions. The contractile proteins are but following the lead of the cellular elements concerned with the production of energy.
The Possible Role of Calcium in Excitation-Contraction Coupling of Heart Muscle
Authors: Brooks Chandler McC. , WINEGRAD SAUL
Published: June 2012

The transfer of Ca
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at rest and during contraction has been measured in isolated guinea-pig atria. During contraction, the rate of transfer increases considerably. The increment in the uptake of calcium by the cells of the atria during contraction is closely correlated with the strength of contraction. This relationship is maintained at different frequencies of stimulation and at different concentrations of external calcium.
Cardiac Active Principles in Blood Plasma
Authors: Brooks Chandler McC. , HAJDU STEPHAN , LEONARD EDWARD
Published: June 2012

A study of isolated frog hearts suggests that the amphibian heart is provided normally with a substance that maintains contractility and that disappears slowly from the heart during perfusion with saline solution. A search for substances that might fulfill this role in the frog heart has led to the isolation of many materials that have some degree of cardiotonic activity, but no conclusion can yet be reached about which, if any, of these substances is present in. the intact frog heart. The search has led, however, to the discovery of 2 substances of mammalian origin that are as potent as the cardiac glycosides with respect to their inotropic action on frog heart. One of these is a phospholipid called lysolecithin, the other is a system of 3 plasma globulins called "cardioglobulin A, B, and C." The concentration of cardioglobulin C in man is increased in essential hypertension and aortic stenosis, 2 unrelated conditions that have in common the development of increased left ventricular isometric tension in systole. Conversely, cardioglobulin C is decreased in a group of patients with idiopathic congestive heart failure. The discovery of these substances is relevant to the question whether isolated mammalian cardiac tissue becomes hypodynamic in physiologic saline because of the loss of a system that helps maintain normal myocardial contractility. We have noted that most of the studies on isolated strips of mammalian cardiac tissue fail to answer this question, since the strips were probably hypodynamic because of impaired oxygenation or nonphysiologie saline media. Studies from our laboratory indicate that a slow decline in contractility on prolonged washing does occur in isolated mammalian heart tissue, despite good oxygenation and a normal environment with respect to inorganic ions. This can be prevented or reversed by perfusion with mammalian plasma. Along similar lines, it is of interest that, although the decline of performance characteristics of in situ mammalian hearts may be due to many factors, the decline can be prevented by perfusing the coronary system of the in situ heart with blood from a healthy donor animal. The problem, then, has 2 aspects. On the one hand, we must discover the physiologic significance of the potent glycoside-like substances already isolated from mammalian tissue; on the other, we must investigate the beneficial effects of plasma on heart strips or of donor dog blood on in situ hearts. Do these actions occur because of an effect on myocardial metabolism or do they come about because of a plasma substance that enhances myocardial contractility directly?
Familial Idiopathic Cardiomegaly
Authors: SCHRADER WAYNE H. , PANKEY GEORGE A. , DAVIS RICHARD B. , THEOLOGIDES ATHANASIOS
Published: June 2012

Two young adult sisters are described with clinical and pathologic findings of myocardial disease. These cases along with a suggestive family history are presented as examples of familial idiopathic cardiomegaly. Pathologic findings are compared and contrasted with those in the literature, and etiologic concepts are discussed. It is concluded that a congenital myocardial abnormality is the most likely etiology and suggestions for further studies are presented.
A Method of Treatment for Pericardial Pain
Authors: WEISSBEIN ARTHUR S. , HELLER FLOYD N.
Published: June 2012

Two patients are presented, in whom dramatic, complete, and prolonged relief from the pain of acute pericarditis was afforded by left stellate ganglion block. In one, this method was successful after the patient had been virtually incapacitated by pain for 75 days. As far as we have been able to ascertain, this mode of therapy has not been previously employed. The distribution of the pain seemed to implicate the phrenic nerve; however, the relief secured by stellate ganglion block appears contrary to this traditional theory.

It is concluded that the mechanism of pericardial pain is not completely understood but that the current, generally accepted explanations are quite likely inaccurate. The inferior cervical and first thoracic sympathetic ganglia may play a large, if not complete role in the transmission of these pain impulses.

There are several practical aspects to our observations. Stellate ganglion block might be logically employed during the acute phase of pericarditis if the pain is severe, and also when the patient is incapacitated by recurrences. There remains also a virtually unexplored field, the relief of the pain of acute myocardial infarction by this procedure.