bluuebunny/crossref_metadata_2025_split huggingface dataset:
Work Speed as a Measure of an Equivalent Exercise Stress in Subjects of Different Weights
Authors: VAN LINGEN B. , SEAWARD P. D. , ODENDAAL W. A. , Kennedy I. M. 
Published: June 2012

The use of work speed, as opposed to work load, as a predictive variable for heart rate during steady state submaximal exercise, increased the correlation and decreased the standard error of the prediction around the regression line. In addition, the relationship of pulse rate and work speed was shown to be independent of body weight, while the relationship of pulse rate and work load was influenced by the body weight.
The establishment of a submaximal exercise test, which would be an equivalent physiologic stress in subjects of different weights, would require that they perform exercise at a similar work speed rather than at a constant work load. Such recommendations, in addition, are at variance with those previously made in regard to subjecting individuals of different weights to an equivalent exercise stress.
Coronary Calcification
Authors: EGGEN DOUGLAS A. , STRONG JACK P. , MCGILL HENRY C. 
Published: June 2012

Measurements of the per cent of the surface with calcified lesions have been made for the three main coronary arteries from 1,242 consecutive necropsies of whites and Negroes between the ages of 30 to 69 years.
Calcified lesions were most prevalent and most extensive in the left anterior descending branch and occurred with greatest frequency at 2 to 3 cm. from the orifice. Whites had greater involvement than Negroes and males had greater involvement than females. Prevalence and extent of calcification have been compared in four cause-of-death or disease categories; cases dying of coronary heart disease had greater involvement than the other three groups.
The prevalence of ischemic myocardial lesions, complicated coronary lesions, or stenotic lesions was greater for cases with calcified lesions, and this prevalence increases with increase in extent of calcified lesions. The significance of the presence of coronary calcified lesions for the diagnosis of advanced coronary atherosclerosis is greatest for younger individuals.
Elective Countershock in Unanesthetized Patients with Use of an Esophageal Electrode
Authors: MCNALLY E. M. , MEYER E. C. , LANGENDORF R. 
Published: June 2012

A new electrode arrangement for the administration of elective direct-current countershock was studied, in which one electrode was placed in the esophagus, adjacent to the heart, and the other on the precordium.
Thirteen patients with chronic atrial fibrillation were converted to sinus rhythm by the esophageal technic. Though the majority were, on clinical grounds, difficult cases for conversion, 11 were converted with shocks of 40 watt-seconds or less, and two with 60, after 40 failed. Five patients were defibrillated by both the esophageal and the conventional, anteroposterior chest technics; the energy requirement with the esophageal method averaged less than one third of that with the conventional one. Four patients received 40, and one 30 watt-second shocks without anesthesia; all five tolerated the shocks well, and three of four who had had countershock previously under anesthesia, expressed preference for the esophageal technic without anesthesia in the future. All patients were observed carefully for any symptoms suggestive of esophageal injury or dysfunction. None such occurred, either immediately or within 4 months.
We conclude that this technic may have a place in elective countershock in that it may allow cardioversion to be undertaken in many patients who would otherwise require anesthesia.
Etiologic Considerations in Peripheral Vascular Diseases of the Lower Extremity with Special Reference to Diabetes Mellitus
Authors: BLUMENTHAL HERMAN T. , BERNS ALINE W. , GOLDENBERG SIDNEY , LOWENSTEIN PAUL W. 
Published: June 2012

A histopathologic and immunopathologic study of changes in small vessels has been carried out on 168 amputated lower extremities. No difference was found in respect to the frequency of thrombotic or atheromatous lesions among the various clinical disease categories necessitating amputation. An increased frequency of inflammatory lesions of small vessels was found only in cases of osteomyelitis. The frequency of hemodynamic lesions was highest in nondiabetic subjects with arteriosclerosis, and second highest in diabetic subjects with arteriosclerosis, followed by thromboangiitis obliterans. Proliferative endothelial lesions were encountered most frequently in diabetes with arteriosclerosis, in osteogenic sarcoma, and in osteomyelitis. Such proliferative lesions were encountered in 80 per cent of diabetic subjects and in 20 per cent of nondiabetic individuals.
Fluorescent insulin binding by small vessels was found in 70 per cent of diabetic subjects with proliferative vascular lesions and in only 30 per cent of diabetic individuals without this proliferative microangiopathy. Such insulin binding was observed in 54 per cent of diabetic subjects and in only about 15 per cent of nondiabetic patients. The binding of fluorescent rabbit antihuman globulin was observed in 56 per cent of diabetic subjects and in 22 per cent of nondiabetic patients.
These findings are discussed in relation to the thesis that there may be diseases of immune origin primarily involving small peripheral vessels. The peripheral vascular disease of diabetes is particularly stressed here because it is probably the most common form of such disease of immune origin. Such pathologic processes in small vessels may secondarily involve large cognate system arteries, either by creating an increased peripheral resistance to the flow of blood or when lesions involve the vasa vasorum, there may be impairment of local nutrition. Either or both of these phenomena could intensify the development of arteriosclerosis of large trunk arteries.
Although no attempt has been made here to justify or negate the existence of thromboangiitis obliterans as a disease entity, it has been pointed out that at least some cases with this diagnosis may have a similar immune origin.
Infarction Patterns in Endocardial Fibroelastosis
Authors: LINTERMANS JOHN P. , KAPLAN EDWARD L. , MORGAN BEVERLY C. , BAUM DAVID , GUNTHEROTH WARREN G. 
Published: June 2012

Three cases of endocardial fibroelastosis with vectorcardiographic findings suggestive of an anterior myocardial infarct are presented. It had been previously reported that such vectorcardiographic features were diagnostic of anomalous origin of the left coronary artery. We conclude that the two diseases cannot be differentiated on the basis of electrocardiography or vectorcardiography alone.
Two of the cases presented were in identical twins; serial scalar electrocardiograms and vectorcardiograms were obtained during the development and progression of endocardial fibroelastosis.
Evaluation of the Severity of Mitral Stenosis and Regurgitation
Authors: LIBANOFF ALBERT J. , RODBARD SIMON 
Published: June 2012

Indices have been developed that provide an improved means for evaluation of the degrees of severity of mitral stenosis and regurgitation. The severity of anatomic mitral valve disease found at surgery or autopsy was considered to be the determinant of the state of the valve. An index of the time for the diastolic atrioventricular pressure gradient to fall to half its value multiplied by 100 and divided by the cardiac index was shown to be comparable to the severity of anatomic stenosis. This index ranged from 5.7 to 10 in mitral stenosis, 0.4 to 0.8 in normal subjects, and 0.6 to 2.0 in patients with predominant mitral regurgitation.
Mitral regurgitation was estimated by an index of the rate of the atrial pressure rise during ventricular systole in mm. Hg/0.02 second multiplied by 10, and divided by the cardiac index. In predominant mitral regurgitation, this index ranged from 8.0 to 15; in mitral stenosis these values were 3.7 to 6.3, and normal subjects had an index varying from 2.5 to 3.7.
Both indices were significantly elevated in patients in whom stenosis and regurgitation were present at surgery. Mitral stenosis complicated by a mild degree of regurgitation gave significantly elevated stenotic indices, while the regurgitation indices were normal or slightly elevated. These indices facilitate the evaluation of either mitral stenosis or regurgitation even when both processes are present together.
The significance of these indices in the evaluation of the degree of invalidism in patients with valvular disease is also discussed.
Epidemiological Study of the Electrocardiographic Diagnosis of Left Ventricular Hypertrophy
Authors: OSTRANDER LEON D. 
Published: June 2012

Electrocardiograms from 5,129 examined persons, 2,449 men and 2,680 women, 16 years of age or older, were classified according to the Minnesota code of Blackburn and associates.
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The R wave amplitude criteria for possible left ventricular hypertrophy were fulfilled in 193 tracings from 135 men and 58 women. Age and sex matched controls were randomly selected from the remainder of the examined population for similar measurement. Those with high amplitude R waves and their controls were grouped according to age, sex, and possible cause for anatomical left ventricular enlargement. Precise measurements were made of all the amplitudes and intervals necessary for the application of a variety of other differential items from current diagnostic criteria. The prevalence of the various differential items in the high amplitude and control groups and the frequency with which each was associated with a cause for enlargement indicated their relative sensitivity and specificity.

Among the individuals with electrocardiographic evidence of left ventricular hypertrophy according to the Minnesota criteria, there were more persons in the upper and lower quintiles of the relative weight distributions, more hypertensives, more persons with roentgenographic evidence of cardiomegaly, and fewer persons in congestive heart failure than among the controls, but the differences were slight.
Most QRS amplitude items were too nonspecific to be of much diagnostic value among young men, and the same items apparently lack sensitivity when applied to the tracings from older women. The items which constitute the Minnesota criteria are useful for screening purposes.
Single items are unreliable for the detection of left ventricular hypertrophy and certain combinations are suggested to improve diagnostic accuracy. Still the electrocardiogram is often an inexact method for the recognition of left ventricular hypertrophy and the diagnosis should be based on careful physical and roentgenographic examinations as well.
Effects of Changes in Body Position on the Severity of Obstruction to Left Ventricular Outflow in Idiopathic Hypertrophic Subaortic Stenosis
Authors: MASON DEAN T. , BRAUNWALD EUGENE , ROSS JOHN 
Published: June 2012

The circulatory responses to alterations in posture were determined in 10 patients with idiopathic hypertrophic subaortic stenosis. Tilting to a 45° head-up position augmented the subaortic gradient by an average of 35 mm Hg and intensified the obstruction to left ventricular outflow. In addition, the post-extrasystolic decrease of the arterial pulse pressure became more prominent. Tilting to a 20° head-down position reduced the gradient by an average of 11 mm Hg and tended to reduce the severity of the obstruction. Elevation of the lower extremities also resulted in a reduction of the intraventricular systolic pressure gradient, the reduction averaging 28 mm Hg, and apparently increased the dimensions of the obstructing orifice.
It is postulated that these effects on the obstruction to outflow induced by changes in posture result primarily from alterations in left ventricular volume secondary to changes in venous return. As a consequence, in the upright position, the size of the left ventricular outflow tract is reduced and the intraventricular pressure gradient is augmented while the cardiac output is reduced, resulting in an intensification of the obstruction. The opposite changes occur during the head-down tilt or during elevation of the legs.
These hemodynamic findings provide an explanation for the intensification of symptoms commonly experienced by patients with idiopathic hypertrophic subaortic stenosis in the erect position, and for the discrepancies between the symptoms and the severity of obstruction determined by cardiac catheterization carried out in the supine position. Assumption of the head-down, legs-up position is suggested as an emergency therapeutic maneuver for patients with hypertrophic subaortic stenosis.
Effects of Amyl Nitrite in Aortic Valvular and Muscular Subaortic Stenosis
Authors: HANCOCK E. W. , FOWKES W. C. 
Published: June 2012

The effects of amyl nitrite inhalation were observed in 12 patients with aortic valve stenosis and five patients with muscular subaortic stenosis during left heart catheterization. In aortic valve stenosis the left ventricular systolic pressure always fell, although less than the brachial arterial pressure, and the transaortic systolic pressure gradient rose by an average of 25% due to the increase in left ventricular ejection rate. In muscular subaortic stenosis, the left ventricular pressure always remained the same or rose despite a marked fall in brachial arterial pressure, and the average increase in transaortic systolic pressure gradient was more than fourfold. This effect was associated with a significant increase in the degree of outflow tract obstruction. The increase in outflow tract obstruction is thought to be due to a decrease in left ventricular volume, causing the hypertrophied walls of the left ventricle to become more closely apposed.
We believe that inhalation of amyl nitrite is superior to infusion of isoproterenol as a provocative test for muscular subaortic stenosis during cardiac catheterization and is probably the most potent stimulus available for this purpose.
Heart Weight of Jamaicans
Authors: HAYES J. A. , LOVELL H. G. 
Published: June 2012

The heart weight and the weights of the component parts have been measured in a group of 126 Jamaicans of African origin on whom autopsy was performed at the Pathology Department of the University of the West Indies. This series comprised 58 normal [see table in the PDF file] cases, 46 cases of hypertension, and 22 cases of chronic lung disease.
The mean heart weight for normal males was 294.5 g and for females 258.5 g. These figures are similar to those reported from Uganda but less than those from Britain and North America. The differences in heart weight are probably correlated with difference in body size.
Total heart weight in the hypertensives was greater than in normals because of left ventricular hypertrophy. In chronic lung disease total heart weight was greater than that of normals due to enlargement of the right ventricle and of the combined atria. Right ventricular weight was also increased in cases of hypertension.
The Cardiomyopathy of Progressive Muscular Dystrophy
Authors: PERLOFF JOSEPH K. , DE LEON ANTONIO C. , O'DOHERTY DESMOND 
Published: June 2012

A prospective study was undertaken in order to examine the histories, physical signs, phonocardiograms, electrocardiograms, vectorcardiograms, X-rays, serum enzymes, pulmonary ventilatory findings, and hemodynamics in a group of 55 patients selected solely on the basis of one of the major types of progressive muscular dystrophy (table 9). The classification included: (1) the classic Duchenne type, (2) the limb girdle type, (3) the facioscapulohumeral type, and (4) a group of patients in whom clinical distinction between benign Duchenne dystrophy and limb girdle dystrophy with pseudohypertrophy could not be made. No patient had recognized heart disease prior to selection. Follow-up periods ranged from a few months to 5 years. The pertinent literature was extensively reviewed.
In all groups clinical evidence of heart disease had to be interpreted in the context of the influence of the somatic musculoskeletal defects on "cardiac" symptoms, cardiovascular physical signs, and radiological appearance of the heart. On the other hand, convincing evidence of intrinsic heart disease-subtle to overt-was found in each of the major categories of progressive muscular dystrophy. Detection of cardiomyopathy was simplest and most frequent in the classic Duchenne group because of the highly characteristic features of the scalar electrocardiogram which might direct attention to the systemic myopathy prior to its clinical recognition. However, the presence of heart disease in patients with forms of dystrophy other than the classic Duchenne deserves particular emphasis. Evidence of cardiomyopathy in these latter forms varied from subtle quadruple gallop rhythms in the limb girdle and facioscapulohumeral groups to cardiomyopathic death in the benign Duchenne and limb girdle-pseudohypertrophic group.
Currently available information on the heart in muscular dystrophy has as a rule depended upon retrospective studies, upon reviews of published reports of incompletely classified cases, upon discussions of individual cardiovascular features, or upon observations of individual types of dystrophy. The present prospective study was undertaken to obviate some of these shortcomings. Comprehensive assessment of a large and carefully classified group of dystrophic subjects has provided additional information regarding the clinical spectrum of dystrophic cardiomyopathy.
Staged Correction of Total Transposition of the Great Vessels
Authors: REED WILLIAM A. , LAUER RONALD M. , DIEHL ANTONI M. 
Published: June 2012

Proper selection of palliative operation for transposition of the great vessels must be based on a careful anatomical and physiological diagnosis. Subsequent correction, utilizing the interatrial baffle technique, is possible with low risk in selected patients.
Details of the clinical course of four patients with transposition from birth to total correction are presented.
Clinical Considerations in the Surgical Management of Strokes
Authors: THOMPSON JESSE E. , KARTCHNER MARK M. , AUSTIN DALE J. , WHEELER CLARENCE G. , PATMAN RALPH D. 
Published: June 2012

Four hundred carotid endarterectomies were performed on 320 private patients with cerebrovascular insufficiency during an eight-year period. Patients are classified into four groups: frank stroke (135 patients), transient cerebral ischemia (151 patients), chronic cerebral ischemia (13 patients), and asymptomatic bruit (21 patients). Over-all operative procedure mortality was 3.5%. In frank strokes it was 7.4%; in transient ischemia, 1.02%; and in the other two groups was zero. As a safety factor during operation, the routine use of an inlying bypass shunt is advocated.
Of 60 long-term deaths, six (10%) were due to strokes. Among frank stroke survivors, 42.8% are normal, and 48.4% are improved. One patient had a mild subsequent stroke. In transient ischemia survivors, 88.4% are normal, and 7% are improved. Three patients had strokes due to unoperated lesions. Surgery appears to have lowered the incidence of strokes in these groups. There were no strokes in the other two groups.
Indications for and timing of operative procedures are suggested on the basis of the clinical results. Transient ischemia, chronic ischemia, and asymptomatic bruit patients may be operated upon electively unless an imminent total occlusion demands emergency operation. Acute and rapidly progressing strokes should not be operated upon as an emergency, but allowed to stabilize and be considered for surgery at a delayed time.
The concept of total cerebral blood flow is discussed in relation to its therapeutic implications and the reversibility of neurological deficits. Carotid endarterectomy is a safe, definitive therapy in selected patients with cerebrovascular insufficiency.
Experimental Microvascular Suture Anastomosis
Authors: GREEN GEORGE E. , SOM MAX L. , WOLFF WILLIAM I. 
Published: June 2012

To evaluate the limits imposed by blood vessel size on success or failure of vascular anastomosis by suture techniques, tiny vessels in young CFN rats were anastomosed by microsuture technique, using the Zeiss operating microscope at 16 and 25 magnifications. In series I aortae averaging 1.3 mm external diameter prior to manipulation were divided transversely and rejoined by suture anastomosis. In series II inferior venae cavae averaging 2.7 mm external diameter prior to manipulation were similarly treated. In series III both of these procedures were performed in each animal. There were ten animals in each group.
Of 40 consecutive anastomoses only three were not patent when the animals were sacrificed three weeks after surgery. Two of the failures were arterial, and one was venous. This high success rate was achieved only when certain refinements in technique had been perfected.
The feasibility of suture anastomosis of extremely small veins as well as arteries has been demonstrated.
Hemodynamic Effects of a Totally Corrective Procedure in Transposition of the Great Vessels
Authors: KIDD LANGFORD , MUSTARD WILLIAM T. 
Published: June 2012

1. The hemodynamic findings in four children with transposition of the great vessels who have been completely corrected are described and contrasted with the findings before and after the initial creation of an atrial septal defect.
2. All four cases exhibit full arterial oxygen saturation and have normal atrial pressures. The pressure tracings in the atria suggest that the pericardial baffle does not interfere with their function.
3. It is suggested that the left ventricle in transposition of the great vessels may assume the compliance characteristics of a normal right ventricle.
4. It is concluded that with this procedure it is possible to restore normal cardiac function and systemic oxygenation in children with complete transposition of the great vessels.
Use of Corticosteroids During Cardiopulmonary Bypass: Possible Lysosome Stabilization
Authors: REPLOGLE ROBERT L. , GAZZANIGA ALAN B. , GROSS ROBERT E. 
Published: June 2012

1. These studies suggest that massive doses of dexamethasone may stabilize the lysosome membrane during periods of circulatory stress.
2. Some of the postoperative complications following cardiopulmonary bypass may be related in part to lysosome damage incurred during bypass.
Demonstration of Intercoronary Anastomoses in Human Hearts with a Low Viscosity Perfusion Mass
Authors: ROBBINS S. L. , SOLOMON M. , BENNETT A. 
Published: June 2012

The coronary arteries of 120 nonselected human hearts were perfused with a low viscosity radiopaque medium comprising essentially a suspension of barium sulfate in agar. In each of four groups of 30 hearts, one major artery was perfused, that is, right coronary, left main coronary, left anterior descending trunk, or left circumflex trunk. Anastomoses were detected either by cross-filling of unperfused vessels or by direct stereoscopic visualization. Anastomoses were demonstrable in 84% of the entire series, but the frequency varied between the four groups (right coronary 93%, left main coronary 90%, left anterior descending 90% and left circumflex 60%). The presence of stenotic disease did not seem to affect the frequency of demonstrable stenosis since 84% of the hearts virtually free of arterial disease contained recognizable stenoses as compared with 92% of hearts with a stenosis of more than 50% of the arterial lumen. Neither did age, hypertension or left ventricular hypertrophy produce any alteration in the frequency rates. There were seven hearts with occlusive disease; only five contained demonstrable anastomoses. The 19 hearts in the total series in which anastomoses could not be found were derived from patients, some of advanced age, some young, some having occlusive arterial disease and some hypertension.
The results of the study suggest that anastomoses are present in most hearts unrelated to clinical disease. They may be increased in size or number by factors that affect coronary hemodynamics, but the present study does not investigate this possibility.