bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodynamic Patterns in Essential Hypertension
Authors: FINKIELMAN SAMUEL , WORCEL MANUEL , AGREST ALBERTO
Published: June 2012

Hemodynamic studies, including cardiac output, arterial blood pressure, run-off index, flow cessation pressure, and blood volume, were performed in 20 normotensive control subjects, 17 labile hypertensive patients and 20 patients with fixed hypertension, 10 of them with a mild elevation of the diastolic pressure and 10 classified as severe because of a diastolic blood pressure above 110 mm. Hg.

In labile hypertension cardiac output was elevated, whereas blood volume, peripheral resistance, run-off index and flow cessation pressure were normal when blood pressure was high. This hemodynamic pattern was interpreted as due to an enhanced myocardial contractile energy or a restriction of the capacity vascular bed.

In mild fixed hypertension total peripheral resistance and flow cessation pressure were uniformly increased, but cardiac output and run-off index were normal. This pattern may be explained by the influence of flow autoregulation and the barostatic mechanism.

In severe fixed hypertension blood volume, cardiac output, and peripheral resistance were found to be high. Renal ischemia and secondary hyperaldosteronism may determine the development of this last stage of hypertension.
Severe Mitral Regurgitation Secondary to Ruptured Chordae Tendineae
Authors: SANDERS CHARLES A. , SCANNELL J. GORDON , HARTHORNE J. WARREN , AUSTEN W. GERALD
Published: June 2012

Fifteen cases of severe mitral regurgitation secondary to ruptured chordae tendineae have been reviewed, eight of whom underwent open-heart surgery to correct their lesions. Three patients are living at this time with two being markedly improved. Cardiac catheterization was performed in six prior to surgery.

Progressive deterioration within the year following the onset of difficulty or sudden worsening of previous cardiac symptoms characterized the usual clinical course. The apical systolic murmur, always loud, was conspicuously harsh and radiated to the base of the heart, simulating aortic stenosis when the mural cusp was ruptured. Although strongly suggesting the diagnosis, the sudden onset of an apical systolic murmur could be documented in only three instances. The presence of a small left atrium radiographically with tall left atrial "v" waves and marked reflux of contrast material into a paradoxically pulsating left atrium also pointed to the correct diagnosis.

Various technics of surgical repair and problems influencing survival of patients in the present series are discussed.
Persistent Hypokalemia Following Open-Heart Surgery
Authors: EBERT PAUL A. , JUDE JAMES R. , GAERTNER ROBERT A.
Published: June 2012

Six patients who exhibited persistent hypokalemia after open-heart surgery with a dilute blood perfusion mixture are discussed. All these patients had acquired heart disease with heart failure as their predominant problem and had been on long-term diuretic treatment with oral potassium replacement. It was not possible to predict with any degree of certainty which patients would develop hypokalemia postoperatively, but the clinical points discussed indicated that frequent measurement of serum potassium was necessary until the value appeared stable. The authors think that the hypokalemia results from long-term tissue potassium depletion, and that hemodynamic improvement following open-heart surgery may facilitate the return of potassium into the cells and thus reduce the serum level.
Ventricular Fusion Beats during Electric Stimulation in Man
Authors: LINENTHAL ARTHUR J. , ZOLL PAUL M.
Published: June 2012

Quantitative studies of ventricular fusion beats were made in 40 patients with Stokes- Adams disease after implantation of electric pacemakers in the left ventricle. The two fusing complexes came from an electric pacemaker and either a second electric pacemaker or a conducted sinoatrial beat. The limit of fusion, that is the maximal time between two fusing complexes, gives a measure of the conduction time and velocity between the two points of initial ventricular depolarization.

Conduction between two electric pacemakers and in retrograde direction from an electric pacemaker to the point of entry of a conducted beat was by way of ordinary myocardium; its velocity was about 1 meter per second. Conduction in antegrade direction, on the other hand, was by way of specialized Purkinje tissue; and its velocity was 4.5 to 9 times faster.

Variations in conduction times with bundle-branch block support this interpretation: retrograde conduction time did not change; antegrade conduction time was prolonged in left but was usually unchanged in right bundle-branch block.

The morphologic similarities of fusion beats in our patients to the features of anomalous AV excitation add strong evidence in man to the previous analogous experimental observations that the WPW complex is a fusion beat. Furthermore, quantitative comparison of WPW and our fusion beats supports the theory that the anomalous excitation in the WPW phenomenon, like the peripherally located artificial stimulus, enters the ventricle peripherally, by way of an accessory AV pathway.
The Prognosis in Aortic Dissection (Dissecting Aortic Hematoma or Aneurysm)
Authors: MCCLOY RANDOLPH M. , SPITTELL JOHN A. , MCGOON DWIGHT C.
Published: June 2012

Between 1945 and 1961 50 patients with aortic dissection were seen at the Mayo Clinic. Survival information for prognostic purposes was available in 40 patients and revealed that more than half of the patients were dead within a week. Of 15 patients who survived the acute phase (2 weeks) more than half were dead within a year. The cause of death was determined by necropsy in 24 patients and 22 died of external rupture of the dissecting aneurysm. In 11 patients a site of re-entry in the dissection was found and in all of these patients external aortic rupture had occurred also. The surgical approach to the treatment of aortic dissection is discussed in the light of these findings. The relationship of the location of the primary tear, blood pressure, and the age of the patient to prognosis is reviewed.
Calculation of Cardiac Output from Indicator-Dilution Curves in the Presence of Mitral Regurgitation
Authors: RAHIMTOOLA SHAHBUDIN H. , SWAN H. J. C.
Published: June 2012

Cardiac output was determined by the indicator-dilution technic with injection of indicator into the ascending aorta, left ventricle, and pulmonary artery in 13 cases of mitral incompetence and in 15 control cases (normal or mild valvular obstruction). The ascending aortic dye curve is not involved in mitral incompetence in its primary circulation and was used for comparison.

In normal subjects, there is no significant difference between the cardiac output obtained by injection of indicator into the ascending aorta and the left ventricle.

The cardiac output obtained from indicator-dilution curves affected by mitral regurgitation in its primary circulation is underestimated by approximately 20 per cent.

The effects of the coronary recirculated indicator particles on the disappearance slope would best explain the discrepancy. Even in the normal circulation, the inclusion of the coronary recirculated particles leads to a small underestimation of the cardiac output when the indicator is injected into the pulmonary artery.
Hemodynamic Consequences of the Injection of Radiopaque Material
Authors: FRIESINGER G. C. , SCHAFFER JOCHEN , CRILEY J. MICHAEL , GAERTNER ROBERT A. , ROSS RICHARD S.
Published: June 2012

The hemodynamic changes resulting from injection of radiopaque material into the left heart in a series of patients undergong cineangiographic studies have been reported. The hypertonicity of radiopaque materials appears to be responsible for much of the observed reaction. The mechanism whereby hypertonic solutions produce the observed physiologic changes remains unknown.

Changes observed in patients could be reproduced in experimental animals. The combined experimental and clinical data show that left atrial pressure increases, left atrial pulse contour alters, stroke output increases, heart rate is much unchanged, peripheral artery pressure falls, hematocrit level falls, and myocardial contractile force decreases mildly and transiently.

The difference between the physiologic effects of injecting hypertonic media into the right and left sides of the circulation is discussed.

Because the pressure changes are easy to monitor and parallel the other features of the hemodynamic reaction, it is good to wait until pressures have returned to the pre-angiographic level before proceeding with the injection of more radiopaque material. This usually requires 15 minutes.
Massive Pulmonary Arteriovenous Fistula in the Newborn
Authors: HALL ROBERT J. , NELSON WILLIAM P. , BLAKE HU A. , GEIGER JAMES P.
Published: June 2012

A case of massive pulmonary arteriovenous fistula, diagnosed and treated in the first week of life is reported. A concept of severely altered intrauterine and neonatal pulmonary blood flow is proposed, with consequent left ventricular overload manifested electrocardiographically by left axis deviation and left ventricular preponderance. Consideration of this malformation in seriously ill cyanotic infants with a radiographic density and these electrocardiographic changes is essential, since this is a surgically curable lesion.
Hemodynamic Findings Following Replacement of the Mitral Valve with the University of Cape Town Prosthesis
Authors: BECK W. , FERGUSSON D. J. G. , BARNARD C. N. , SCHRIRE V.
Published: June 2012

Postoperative hemodynamic studies have been performed on 11 subjects following replacement of the mitral valve. In eight cases a comparison was made with the preoperative findings.

The great improvement in the functional capacity of most patients is reflected in the findings of this study, which indicate a small gradient at rest across the prosthesis and no mitral incompetence. The residual gradient was thought to be due mainly to inadequate orificial size, although delay in reaching the fully open position may also play a part.

In two subjects a severely elevated pulmonary vascular resistance fell markedly following the relief of left atrial hypertension.

Two patients failed to show sustained clinical and hemodynamic improvement. In one, mild aortic valve disease was present and severe systemic hypertension developed, resulting in death. The influence of these factors is discussed. In the other, the cause for the continuing heart failure with poor left ventricular contractility was undetermined.
A New Method Utilizing Indicator-Dilution Technics for Estimation of Left-to-Right Shunts in Infants
Authors: KROVETZ L. JEROME , GESSNER IRA H.
Published: June 2012

The short circulatory pathways of infants cause rapid systemic and pulmonary circulation times. So rapid are they that the usual methods for calculating left-to-right shunts frequently yield a considerable overestimation. A new formula was described for use with injections into the left heart and arterial sampling. This formula applied to 11 infants and 7 older patients showed a significantly better correlation with oximetric calculations than did the right heart injections. This method also will reveal the presence of a left-to-right shunt that is of insufficient magnitude to distort dye curves obtained following right heart injections.
The Effect of Exercise on Postural Changes in the Electrocardiogram
Authors: BELLET SAMUEL , ROMAN LAURIAN
Published: June 2012

The electrocardiogram before, during, and after a double two-step exercise test was studied in the upright position in 1,026 subjects with no apparent heart disease and in 70 patients with angina. Postural changes were found much more frequently in subjects with angina (18.5 per cent) and in apparently normal subjects with positive exercise tests (10.7 per cent) than in normal subjects with negative exercise tests, in which postural changes were found in only 3.4 per cent. Probable causes for these findings are discussed.

The criterion for positivity in over 80 per cent of exercise tests, namely, an ischemic ST depression, is rarely seen as a postural change in normal subjects. On the other hand, isolated T-wave changes, which represent approximately 90 per cent of the postural changes of the repolarization period, are very rarely the sole criteria for a positive exercise test. Therefore, only a small area of possible confusion exists between postural changes and positive exercise tests. However, even in such cases, careful examination of the tracings can resolve these difficulties.
Bacterial Endocarditis Following Aortic Valve Replacement
Authors: COHN LAWRENCE H. , ROBERTS WILLIAM C. , ROCKOFF S. DAVID , MORROW ANDREW G.
Published: June 2012

The clinical and pathologic findings in three patients with bacterial infection at the sites of prosthetic aortic valves are described. Each presented typical clinical features of acute bacterial endocarditis followed by the sudden development of severe and ultimately fatal aortic regurgitation. Pathologically the infectious process was characterized by extensive necrosis of the aortic annulus, disruption of the aortic wall, and the formation of abscesses in the periaortic tissues. In two patients the prosthetic valve was partially detached from the annulus, whereas in the other it was totally dislodged and impacted in the aortic arch shortly before death. In all, secondary operative intervention would have been fruitless because of the extent of the infection and the character of the tissue at the aortic root. In one patient fatal staphylococcal endocarditis followed dental extractions despite penicillin prophylaxis. A more comprehensive antibiotic regimen for patients with prosthetic cardiac valves is suggested.
Studies of Cardiopulmonary Blood Volume
Authors: LEVINSON GILBERT E. , PACIFICO ALBERT D. , FRANK MARTIN J.
Published: June 2012

The volume of blood in the heart and lungs can be measured, by the Stewart-Hamilton principle, as the product of cardiac output and the mean transit time from right atrium to the aortic root. Although previous investigators have estimated a variety of central blood volumes, measurements of the true cardiopulmonary blood volume in man have not previously been reported.

Eighty-one measurements of the total cardiopulmonary blood volume were obtained in 15 normal human subjects. At rest, total cardiopulmonary blood volume ranged from 301 to 546 ml/m
2
, with a mean of 422 ml/m
2
, and it represented 15% of estimated total blood volume. Cardiopulmonary blood volume was significantly larger in the male subjects than in the female. Reproducibility of measurements was good: the mean discrepancy between successive replications was 25 ml/m
2
and the mean coefficient of variation 3.7%. There was no correlation between cardiac output and cardiopulmonary blood volume but a significant correlation (r=0.79,
P
<0.0001) was evident between cardiopulmonary blood volume and stroke volume.

With elevation of the legs to the pedals of a bicycle ergometer, a small but statistically significant increase occurred in cardiopulmonary blood volume, but no significant changes occurred in cardiac output, heart rate, or stroke volume. With exercise, no further significant change in cardiopulmonary blood volume occurred, despite significant increases in output, rate, and stroke volume.

Analysis of cardiac output measurements, both at rest and during exercise, indicates that aortic root sampling is characterized by an appreciably higher reproducibility than that reported for peripheral arterial sampling.
Renal Circulation in Man Studied by Means of a Dye-Dilution Method
Authors: REUBI FRANÇOIS C. , GOSSWEILER NICOLAS , GUÜRTLER RENÉ
Published: June 2012

A dye-dilution method of measuring renal hemodynamics in man has been described. The method requires catheterization of both the renal artery and the renal vein, a single injection of dye into the renal artery, and recording of the venous dilution curve by means of a cuvette densitometer.

The method was evaluated in 11 normal subjects, eight patients with acute anuric renal failure, and 13 patients with chronic renal disease. In 26 instances the PAH clearance and the PAH-extraction ratio were determined simultaneously. The dye-PAH flow ratio averaged 0.98 for the whole series. The limitations of the dye method have been discussed.

The dye method probably makes it possible to estimate the blood flow distribution within the human kidney. The available data indicate that cortical blood flow in the normal kidney ranges from 80 to 93% of the total flow, with a mean transit time of 5 to 10 sec. The calculated cortical vascular volume ranges from 52 to 78% of the total volume. The extracortical flow presumably represents medullary circulation with a mean transit time of 19 to 25 sec.

In anuric renal failure the total renal blood flow averaged 55% of normal and did not increase significantly during the subsequent polyuria. The shape of the dilution curves remained essentially normal in anuria and polyuria as well.
Vectorcardiographic Studies in Acquired Valvular Disease with Reference to the Diagnosis of Right Ventricular Hypertrophy
Authors: CUETO J. , TOSHIMA H. , ARMIJO G. , TUNA N. , LILLEHEI C. WALTON
Published: June 2012

The orthogonal vectorcardiogram described by Schmitt and Simonson has been studied in 37 patients with "pure" mitral stenosis.

The diagnosis of right ventricular hypertrophy (RVH) could be established from changes in the magnitude, azimuth, and elevations of the initial, middle, and terminal forces, which could not be detected by the routine 12-lead electrocardiogram. This type of [see figure in the PDF file] recording has proved to be of great value in the diagnosis of right ventricular hypertrophy, particularly when the hypertrophy is of mild or moderate degree. Analysis of the instantaneous vectors has proved to be the single most important criterion in the electrocardiographic diagnosis of right ventricular hypertrophy.
The Audible Sounds of Atrial Tachyarrhythmia (Flutter?)
Authors: MASSUMI R. A. , HERNANDEZ T. , JUST G. , TAWAKKOL A. A.
Published: June 2012

A patient with a rapid atrial mechanism (rate approximately 225), categorized as atrial flutter, had audible sounds correlated with the atrial cycle. Second degree heart block was present and the intensity of the sounds increased sequentially during the ventricular diastolic period. Phonocatheter records revealed prominent vibrations related to the atrial cycle in the right atrium, but not in the right ventricle, left atrium, or left ventricle. It is suggested that the flutter sounds represent tension of the atrial wall or the atrioventricular valve at the time of atrial systole and are unrelated to ventricular filling.
Anomalous Systemic Venous Drainage with Hypoplasia of the Right Ventricular Myocardium
Authors: OVERY H. R. , STEINBICKER P. G. , BLOUNT S. GILBERT
Published: June 2012

A case of anomalous systemic venous drainage into the left atrium with right-to-left shunt across an atrial septal defect is presented. Hemodynamic studies, observation during surgical correction of the abnormalities and the occurrence of postoperative heart failure indicated inadequacy of the right ventricular myocardium.
Red Cell Survival in Patients with Mitral Valvular Disease and Mitral Valve Prostheses
Authors: BRODEUR MICHAEL T. H. , KOLER ROBERT D. , STARR ALBERT , GRISWOLD HERBERT E.
Published: June 2012

Red cell survival times were measured in patients with mitral valvular disease, mitral ball-valve prostheses, and multiple valve prostheses. Red cell survival was shortened in patients with mitral valvular disease but not in patients who had insertion of a normally functioning mitral prosthesis or after mitral commissurotomy.

Mean red cell survival was also reduced in patients who had normal mitral prostheses associated with aortic valvular disease and in patients with a leak around the mitral prosthesis.

Mean red cell survival was the same in patients with multiple prostheses and in patients with a single aortic prosthesis. If a leak developed around the mitral prosthesis in patients with multiple prostheses, hemolytic anemia could develop. Renal excretion of iron and iron deficiency were demonstrated in two patients with traumatic hemolytic anemia. The urinary iron loss apparently exceeds the capacity for intestinal absorption, and parenteral iron would seem to be indicated for replacement.
Operative Treatment of Multiple Sites of Extracranial Cervical Artery Occlusion
Authors: HARDIN CREIGHTON A.
Published: June 2012

Arterial reconstruction was done in 130 patients with multiple sites of extracranial cerebral artery occlusion. Operative mortality was 2.3%; total mortality of the operative series was 3.8%. Presenting ocular signs and symptoms, other than diplopia and blurred vision, were essentially unchanged. Paralytic symptoms reverted in 80% of patients. Speech disturbances were relieved in 78% of patients. Attitude, gait, and ataxia returned to normal in 88% of patients. Nystagmus was improved in 76% of patients. Arterial reconstruction of blood flow of multiple sites of cerebral vascular insufficiency carries an acceptable operative mortality and results in a satisfactory reversal of preoperative neurological signs and symptoms.
Open Intracardiac Repair for Complete Transposition of the Great Arteries
Authors: HIGHTOWER BILLY M. , WEIDMAN WILLIAM H. , KIRKLIN JOHN W.
Published: June 2012

Seventeen of 44 patients undergoing operation for complete correction of transposition of the great arteries survived operation and were dismissed to return home. Three late deaths followed. Mortality remains high among infants less than one year old and among patients of all ages who have severely elevated pulmonary vascular resistance.

Nine of the last 13 patients, in whom repair was accomplished by the Mustard technique, have survived. Late results in all surviving patients have generally been excellent.
Glucose Metabolism in Subjects with Behavior Pattern A and Hyperlipemia
Authors: ROSENMAN RAY H. , FRIEDMAN MEYER , BYERS SANFORD O.
Published: June 2012

Men exhibiting an extreme form of behavior pattern type A and preprandial and postprandial hyperlipemia were not found to suffer from any discernible defect in glucose metabolism.
Selective Cine Coronary Arteriography
Authors: PROUDFIT WILLIAM L. , SHIREY EARL K. , SONES F. MASON
Published: June 2012

The clinical records of 1,000 patients who had adequate selective cine coronary arteriography were reviewed. The clinical diagnoses were made by a physician who had no knowledge of the arteriographic findings. Correlation of the clinical diagnoses with the arteriographic findings was made subsequently.

Symptomatic coronary disease was accompanied by arteriographic evidence of significant obstruction of major coronary arteries in most instances. A close correlation existed between the clinical diagnosis of angina pectoris without rest pain and significant arterial obstruction (95%). A similar correlation was found between QRS evidence of myocardial infarction and severe arterial obstruction (99%). The demonstrated arterial obstruction in patients who had angina pectoris almost always was severe and usually almost total or total in one or more major vessels. In myocardial infarction the demonstrated obstruction was always severe and generally almost total or total.

The correlation between clinical and arteriographic findings was moderately close in patients who had angina with symptoms at rest. The correlation between the arteriographic findings and less characteristic clinical syndromes (rest pain only, 79%, coronary failure, 78%, and especially atypical angina pectoris, 65%) was not so close. In congestive failure secondary to coronary disease, arterial obstruction was extensive unless ventricular aneurysm, mitral insufficiency, arrhythmia, arterial hypotension, or some other complication was present. Most patients thought to have noncoronary symptoms had no significant obstructive lesions.

In 37% of the entire group of patients, almost all of whom had been suspected of having coronary disease by some physicians, no significant arteriographic obstruction was demonstrated; in 27% the arteriograms were normal.

Diagnoses, based on appraisal of the clinical records without knowledge of the arteriographic findings, yielded 83% correlation with abnormal arteriographic findings in 700 patients thought to have coronary disease.
Carcinoid Heart Disease
Authors: AROESTY JULIAN M. , DEWEESE JAMES A. , HOFFMAN MARVIN J. , YU PAUL N.
Published: June 2012

A patient with carcinoid syndrome with both tricuspid and pulmonic valvular lesions has been described. Successful repair of the valvular lesions was performed under cardiopulmonary bypass. The operation consisted of pulmonic valvotomy with the excision of a single pulmonic valve cusp, and replacement of the tricuspid valve by a Starr-Edwards prosthesis. Postoperatively, the patient noted marked improvement in symptomatology, and there was a concomitant improvement in serial hemodynamic studies.

The development of the signs of tricuspid regurgitation and pulmonic stenosis in patients with metastatic carcinoid tumor should alert the physician to the possible presence of carcinoid heart disease. If hemodynamic and angiocardiographic studies confirm the presence of significant valvular lesions, corrective cardiac surgery should be performed in selected patients.
Comparative Ultrastructure of the Sinus Node in Man and Dog
Authors: JAMES THOMAS N. , SHERF LIBI , FINE GERALD , MORALES AZORIDES R.
Published: June 2012

Ultrastructure of the sinus node was studied in human and canine hearts and found to be similar. The principal cell of the sinus node is a small round pale cell with randomly distributed sarcosomes and sparse myofibrils. These cells have been designated as P cells. They occur in elongated clusters and make contact with each other in all directions but do not make direct contact with ordinary working myocardium. Transitional cells, which have features intermediate between P cells and working myocardium, serve as the connections between P cells and the rest of the heart. Each P cell is surrounded by a plasma membrane and groups of them are bound by a basement membrane. The only specialized junction between P cells is the desmosome, which occurs singly and seldom, with most contact being between apposing plasma membranes. P cells exhibit unusually active pinocytosis but have only a sparsely developed sarcoplasmic reticulum. The sarcosomes of P cells are much simpler in internal structure than are those of adjacent working myocardium obtained at the same time in the same heart in the same way, by direct perfusion with glutaraldehyde into the beating sinus node. Correlation of the electron microscopic appearance of the sinus node with that based on light microscopy is discussed, and some of the possible functional significances of the fine structure are considered.
Aortic-Left Atrial Communication
Authors: BEACH THOMAS B. , MCCLENATHAN J. E.
Published: June 2012

A case of aortic-left atrial communication is presented in a patient with chronic rheumatic heart disease. The rarity of this lesion, especially in association with rheumatic heart disease, is stressed and the diagnostic and therapeutic problems inherent in such a lesion are briefly discussed.
Vitamin D and the Supravalvar Aortic Stenosis Syndrome
Authors: FRIEDMAN WILLIAM F. , ROBERTS WILLIAM C.
Published: June 2012

Pregnant rabbits were given high doses of vitamin D to determine whether the vitamin crossed the placenta and to explore the relationship between maternal hypervitaminosis D and congenital supravalvar aortic stenosis. The blood levels of antirachitic substance in the mothers given vitamin D and their offspring were 7 and 9 times greater than in the control mothers and offspring, respectively, indicating that transplacental passage occurred. Serum calcium levels in the offspring whose mothers received vitamin D were significantly higher when compared to control values. A total of 14 abnormalities of the aorta were noted in the 34 offspring whose mothers received vitamin D. Aortic lesions that appeared similar anatomically to supravalvar aortic stenosis in man were noted in six rabbits. Also, one rabbit showed a supravalvar fibrous band and another had an abnormality of the proximal portion of the aorta observed only on microscopic examination. Six additional offspring at age 3 months showed generalized vitamin D vasculotoxicity, without supravalvar narrowing of the aorta, of an advanced type commonly seen in the adult animal given massive doses of the vitamin. Thirty-five control offspring and nine rabbits born to mothers on vitamin D-deficient diets showed no abnormalities of the aorta. The results suggest that an
in utero
derangement in vitamin D metabolism on the part of mother or fetus, or of both may be responsible for supravalvar aortic stenosis, especially when the latter is associated with infantile hypercalcemia. The questions raised by the experimental findings are emphasized.
Skin-Electrode Impedance and Its Effect on Recording Cardiac Potentials
Authors: SPACH MADISON S. , BARR ROGER C. , HAVSTAD JAMES W. , LONG E. CROFT
Published: June 2012

Skin-electrode impedance was measured for four different types of conventional electrocardiographic electrodes applied under different conditions. All types of contacts were frequency dependent; a decrease in impedance was found with increasing frequency. Occasionally, impedance values at a frequency range of 6 to 100 cycles per second were in the tens of thousands of ohms with all electrode types. Tracings obtained under working conditions were evaluated to determine the influence of skin-electrode impedance on the recorded data. Single channel electrocardiographs accurately recorded cardiac potentials; however, simultaneously recorded multiple channel data had considerable distortion in half of the subjects. Frank vectorcardiograms demonstrated significant amplitude loss in half of the patients, with the most prominent distortion occurring in the T wave as compared to QRS. The inclusion of a buffer amplifier between the skin-electrode contacts and the resistor network produced distortionfree tracings. The inclusion of such devices is suggested to obviate any potential error produced by the highest skin-electrode impedance contact values obtained under working conditions.
Electrocardiographic Changes Reflecting Left Atrial Abnormality in Hypertension
Authors: TARAZI ROBERT C. , MILLER ANTHONY , FROHLICH EDWARD D. , DUSTAN HARRIET P.
Published: June 2012

To separate the effects of hypertension and atherosclerosis on the left atrium, the electrocardiograms of 76 hypertensive patients and 76 normal control subjects, matched for age and sex, were studied. Four established criteria for left atrial abnormality were used. One or more positive criteria were satisfied in 45 of the 76 patients and 28 had two or more positive criteria. In contrast, only four of the 76 normal subjects had one abnormal criterion; none had more than one. In 37 patients selective coronary cinearteriography was performed and five of these with abnormal P waves had no arteriographic evidence of atherosclerosis. Eleven of 45 patients with left atrial abnormality had repeated episodes of atrial arrhythmias, whereas only one of the 31 patients with normal P waves had an atrial arrhythmia, demonstrating that repeated atrial arrhythmias are more frequent in patients with left atrial abnormality.

Left atrial abnormality was, therefore, a frequent finding in hypertension; it may occur even in the absence of cardiac enlargement and coronary arterial disease. It was, at times, the sole sign of cardiac abnormality in hypertension.
Orthostatic Hypotension as a Clue to Primary Systemic Amyloidosis
Authors: KYLE ROBERT A. , KOTTKE BRUCE A. , SCHIRGER ALEXANDER
Published: June 2012

Data on 11 patients with orthostatic hypotension and primary systemic amyloidosis have been presented. Dizziness and light-headedness or syncope significantly hampered the involved patients. Three were incapacitated by orthostatic hypotension.

Diarrhea, nausea, vomiting, and loss of weight were common, and adrenal insufficiency was seriously considered in the differential diagnosis of six of the 11 patients. Abnormal sweating was found in all six in whom this test was done.

The drug 9-α-fluorohydrocortisone showed promise in symptomatic therapy of the condition. The possibility of primary systemic amyloidosis should be considered in the presence of orthostatic hypotension. Rectal biopsy and bone-marrow aspiration are recommended as initial biopsy procedures unless another organ suitable for biopsy is obviously involved.
The Pulmonary Arterial Bed in Ventricular Septal Defect
Authors: NAEYE RICHARD L.
Published: June 2012

A quantitative, morphological study was undertaken on pulmonary arteries of 45 infants dying with ventricular septal defects; all but one were less than 3¼ years in age at death. All but four had large septal defects and most had evidences of severe pulmonary arterial hypertension. In the first 2 postnatal months, about half of the infants had a near normal mass of pulmonary arterial smooth muscle which correlates with clinical observations of a decreasing pulmonary vascular resistance during this period. Subsequently, almost all had a greatly increased mass of muscle in small pulmonary arteries which was mainly due to hypertrophy of individual smooth muscle cells. This correlates with an increased pulmonary vascular resistance reported in infants with large defects at this age. Finally, infants older than 6 months of age with septal defects had a high incidence of pulmonary arterial thrombi, and intimal proliferative and sclerotic lesions. These latter lesions were probably at an irreversible stage in one 2-year-old and one 3-year-old infant.
The Vectorcardiogram in Complete Transposition of the Great Vessels
Authors: KHOURY GEORGE H. , SHAHER REDA M. , FOWLER RODNEY S.
Published: June 2012

The Frank vectorcardiograms of 50 patients with complete transposition of the great vessels were analyzed, and the findings were correlated with the electrocardiogram and hemodynamics. The patients were divided into four groups according to the presence or absence of ventricular septal defect and left ventricular outflow tract obstruction. In group I, consisting of 20 patients with ventricular septal defect, the vector cardiograms showed evidence of combined ventricular hypertrophy in 80% of the cases, the scalar electrocardiogram, in 40%.

In group II, 13 patients with ventricular septal defect and left ventricular outflow tract obstruction, the vectorcardiogram was consistent with either right, combined, or left ventricular hypertrophy.

In groups III and IV, patients with intact ventricular septum with or without left ventricular outflow tract obstruction, the vectorcardiogram was consistent with right ventricular hypertrophy in the majority of cases.
Mycotic Aneurysms of the Intrapulmonary Arteries
Authors: KAUFFMAN SHIRLEY L. , LYNFIELD JOSHUA , HENNIGAR GORDON R.
Published: June 2012

In the case presented, multiple aneurysms of the peripheral pulmonary arteries occurred in a child with secondary pulmonary hypertension complicated by bacterial endocarditis. Study of other reported cases suggests that pulmonary hypertension may be significantly associated with the development of mycotic aneurysms. As surgical resection of aneurysms has been at least temporarily successful, increased attention may be given to control of infection in these patients and to the appreciation of the frequency of aneurysms of the main pulmonary artery as well as peripheral pulmonary arteries in patients with congenital heart disease and pulmonary hypertension complicated by bacterial endocarditis.
A Hemodynamic Evaluation of Bilateral Nephrectomy and Hemodialysis in Hypertensive Man
Authors: HAMPERS CONSTANTINE L. , SKILLMAN JOHN J. , LYONS JOHN H. , OLSEN JOHN E. , MERRILL JOHN P.
Published: June 2012

Three hypertensive men with end-stage primary renal disease were hemodynamically evaluated before and 3 to 4 weeks after bilateral nephrectomy and before and after 6 hours of hemodialysis with the twin coil artificial kidney. Conclusions include the following: (1) The height of the blood pressure and changes in plasma volume (P.V.) are
not
necessarily
directly
related in the
early
renoprival state. (2) Increased total peripheral resistance (TPR) plays an important role in maintaining elevation of blood pressure after nephrectomy. (3) We cannot document that bilateral nephrectomy has a beneficial effect on the hypertension of chronic renal failure during the first month of the anephric state. (4) Renin is not involved in maintaining elevated blood pressure after nephrectomy. (5) Increased sensitivity to ganglionic blockade may follow nephrectomy if P.V. decreases. (6) No evidence supports the existence of a "cardiodepressor" substance in uremia. (7) Increased blood pressure occasionally seen during hemodialysis is probably related to several factors (increased cardiac output, increased TPR). (8) P.V. may fall during hemodialysis even though body weight is maintained constant. (9) If P.V. is unchanged across hemodialysis, cardiac output usually does not change.
The Precordial Movements in Adults with Pulmonic Stenosis
Authors: HOLT JOHN H. , EDDLEMAN E. E.
Published: June 2012

The precordial movements were studied in 24 adults with pulmonic stenosis. All patients were studied by cardiac catheterization. Normal kinetocardiographic criteria were applied to the patients with pulmonic stenosis. These provided a measure of the magnitude of atrial movements and relative amplitude and duration of movements associated with ventricular systole. Twenty-two patients had abnormal ventricular systolic movements by these criteria. These increased systolic movements are attributed to right ventricular overload. However, the location of these movements was frequently in areas generally considered as reflecting left ventricular activity. Possible explanations for this apparent paradox are discussed. There was a predictable relation between the motions associated with atrial contraction and the right ventricular pressure.
The Vectorcardiogram in Cystic Fibrosis
Authors: LIEBMAN JEROME , DOERSHUK CARL F. , RAPP CLYDE , MATTHEWS LEROY
Published: June 2012

One hundred and one children with cystic fibrosis had detailed studies of the vectorcardiograms and pulmonary function tests. The vectorcardiographic diagnoses were (1) right ventricular hypertrophy (14 patients), (2) right ventricular hypertrophy plus abnormally posterior vector (24 patients), (3) abnormally posterior vector (26 patients), (4) low voltage (nine patients), and (5) tracing within normal limits (35 patients).

Right ventricular hypertrophy correlated well with a decreased vital capacity. Abnormally posterior vector correlated well with increased residual volume and functional residual capacity. The presence of the abnormally posterior vector was demonstrated to be the major factor in the difficulty in interpreting right ventricular hypertrophy from the electrocardiogram, for a large terminal rightward vector was often too far posterior to be registered as a terminal R in the right chest leads.

The Frank system vectorcardiogram was demonstrated to be better able to detect right ventricular hypertrophy than was the cube system vectorcardiogram. This was particularly true in the presence of an abnormally posterior vector.

An abnormally leftward 0.01-second vector, if it is anterior, is frequently seen in right ventricular hypertrophy.
An Autopsy Study of Leg Vein Thrombosis
Authors: STEIN PAUL D. , EVANS HILARY
Published: June 2012

An autopsy study of leg veins in unselected patients was performed in which postmortem venography, complete gross dissection, and microscopic examination were utilized in order to assess the incidence, location, origin, and mode of propagation of venous thrombi in the leg. The incidence of leg vein thrombosis is high; 13 of 27 patients studied (48%) had antemortem thrombi. Thrombosis in the veins of the thigh occurred often (eight patients), but thrombosis in the veins of the calf was even more frequent (12 patients). Thrombi large enough to cause significant pulmonary embolism were found in seven patients. Leg vein thrombi were found in five of the six patients in this study who had pulmonary embolism at autopsy. Initiation of thrombosis was noted in the veins of both the thighs and the calves. The valve pockets were a frequent site of origin of thrombi. Inflammation of the wall of the vein (phlebitis) secondary to thrombosis was found in one patient.

Postmortem venography is a useful and simple adjunct for the autopsy study of leg vein thrombosis. It is particularly reliable for the detection of thrombi in the thigh.
Diagnosis and Surgical Treatment of Infants with Critical Pulmonary Outflow Obstruction
Authors: GERSONY WELTON M. , BERNHARD WILLIAM F. , NADAS ALEXANDER S. , GROSS ROBERT E.
Published: June 2012

The records of 15 infants with pulmonary atresia and 19 infants with critical pulmonic stenosis and intact ventricular septum, all under 1 year of age, have been reviewed. Symptoms started earlier and were more severe in the group with pulmonary atresia. All patients showed arterial unsaturation, and many had congestive heart failure The electrocardiogram was the most helpful tool in differentiating pulmonary atresia from pulmonic stenosis with intact ventricular septum. The presence of P pulmonale, significant right axis deviation, and right ventricular hypertrophy favors pulmonic stenosis. At cardiac catheterization, patients belonging to both groups showed right ventricular hypertension of significant degree, but this was more marked in infants with pulmonic stenosis. Results of surgery for pulmonary atresia with intact ventricular septum, by a variety of methods, have been uniformly poor up to the present. Direct attack on the pulmonary outflow tract, when possible, may offer more promise for the future. Pulmonary valvotomy is the operation of choice for pulmonic stenosis and the results are good.
Evolution of Corrective Surgery for Ebstein's Anomaly
Authors: LILLEHEI C. WALTON , KALKE B. R. , CARLSON ROBERT G.
Published: June 2012

Experience with eight cases admitted to the University of Minnesota Medical Center for surgical treatment of Ebstein's anomaly is presented. Correction by excision of the malformed and malpositioned tricuspid valve with prosthetic valve replacement is advocated as the procedure of choice. Some patients probably need a temporary avenue for right-to-left shunting at the atrial level until the atrialized right ventricle can achieve competence. None of the three patients with significant arrhythmias preoperatively has experienced this difficulty to date, after valve replacement.
Effect of Airway Hypocapnia on Mechanics of Breathing during Cardiopulmonary Bypass
Authors: PATTERSON R. W. , SULLIVAN S. F. , MALM J. R. , BOWMAN F. O. , PAPPER E. M.
Published: June 2012

Total cardiopulmonary bypass separates the lungs from the pulmonary arterial circulation. Continued ventilation with non CO
2
-containing mixtures during bypass will result in airway hypocapnia. Airway hypocapnia results in decreased compliance, increased work of breathing, and increased resistance to air flow. Reversal of airway hypocapnia increased compliance one-third, decreased work of breathing 20%, and decreased air flow resistance approximately 40% when compared to the values obtained during the period of low airway CO
2
. These changes in airway mechanics must be considered for pulmonary management during cardiac bypass.
Resuscitation and Function of the Cadaver Heart
Authors: WUERFLEIN ROBERT D. , SHUMWAY NORMAN E.
Published: June 2012

Cadaver dog hearts with anoxia for one and one-half hours and no cooling were revived with 70% (18 of 26) success. There was occasional success after one and one-half to two hours of anoxia. At two hours no heart could be revived. After resuscitation cadaver hearts were maintained in a functional heart-lung preparation for periods up to 30 hours. Attempts were made to transplant ten of these hearts into the orthotopic position. There were no long-term survivors; all ten, however, were able to take over the circulatory load after bypass. Four dogs maintained an adequate circulation without supportive drugs for from eight to 38 hours.
Muscular Subaortic Stenosis
Authors: WIGLE E. DOUGLAS , AUGER PIERRE , MARQUIS YVES
Published: June 2012

Left ventricular ejection time was correlated with the intraventricular pressure gradient in 35 cases of muscular subaortic stenosis in which simultaneous aortic and left ventricular pressure recordings were available. Ejection times were corrected for heart rate by dividing them by the square root of the cycle length. There was a direct relation between the degree of prolongation of the ejection time and the magnitude of the pressure gradient whether the latter varied spontaneously or followed surgical or pharmacological intervention. The only exceptions occurred in three of nine cases during stimulation of the gradient with isoproterenol.

In contrast, when an intraventricular pressure difference resulted from catheter entrapment in left ventricular myocardium in patients with nonobstructive cardiomyopathy, there was an inverse relation between ejection time and pressure difference, whether the latter varied spontaneously or following pharmacological intervention.

These studies provide further evidence that (1) two types of intraventricular pressure difference may be encountered within the left ventricle of man, and (2) the pressure difference in muscular subaortic stenosis results from obstruction to the left ventricular outflow.
Large and Small Artery Occlusion in Diabetics and Nondiabetics with Severe Vascular Disease
Authors: CONARD MARGARET C.
Published: June 2012

Casts were made of the vascular lumen of 20 successive extremities amputated for gangrene. Half of the patients were diabetic. All nondiabetics had arteriosclerotic vascular disease plus acute occlusion. Only one diabetic had an acute episode. There was no significant difference in age, blood pressure, or digital blood flow between the two groups. Diabetics had somewhat greater occlusion of the calf vessels and less occlusion in the foot than nondiabetics; the overall extent of large artery occlusion was equal in the two groups. There was no increase in small vessel occlusion with diabetes. Small vessel occlusions were present in all areas of muscle and skin examined. The findings indicate that: (1) very extensive occlusion must be present to result in necrosis; (2) in nondiabetics, amputation was required only when sudden occlusion was superimposed on previous occlusive disease; (3) both large and small vessels are occluded to about the same extent in diabetics and nondiabetics when amputation is required, and (4) either diabetes or sudden occlusion in conjunction with chronic vascular disease can result in insufficient collateral flow and subsequent death of tissues.
Cardiac Potentials on Body Surface of Infants with Anomalous Left Coronary Artery (Myocardial Infarction)
Authors: FLAHERTY JOHN T. , SPACH MADISON S. , BOINEAU JOHN P. , CANENT RAMON V. , BARR ROGER C. , SABISTON DAVID C.
Published: June 2012

The body surface potential distribution in two infants with myocardial infarction secondary to anomalous origin of the left coronary from the pulmonary artery demonstrated: (1) the persistence of a minimum in the area overlying the infarct during inscription of the prominent Q wave in V
6
, and, (2) the presence of a terminal maximum in an adjacent area overlying the infarct. The terminal maximum was considered to represent peri-infarction "block" resulting from persistence of wave fronts in the ischemic muscle surrounding the infarct as suggested by the studies of Durrer and associates. Postoperatively, there was persistence of the initial minima overlying the area of the infarct. Finally, there was disappearance or marked diminution in the terminal maximum overlying the area of the infarct following surgical enhancement of myocardial blood supply.