bluuebunny/crossref_metadata_2025_split huggingface dataset:
Common (Single) Ventricle with Normally Related Great Vessels
Authors: MARÍN-GARCÍA JOSÉ , TANDON RAJENDRA , MOLLER JAMES H. , EDWARDS JESSE E. 
Published: June 2012

A rare form of common ventricle with normally related great vessels and normal tricuspid and mitral valves should be considered in the differential diagnosis of cardiac anomalies presenting with cyanosis. Fourteen cases of this type of common ventricle were studied; in seven the diagnosis was made at necropsy and in seven it was based on angiographic evidence. That the common ventricle was morphologically a left ventricle was determined in the seven necropsy cases, and angiocardiographic examination confirmed the finding in the others. Continuity of the aortic valve and the mitral valve was observed in all the necropsy cases and in five of the clinical cases. Cyanosis had been observed clinically in 13 of the 14 cases, and pulmonary stenosis was present in four necropsy and three clinical cases. Electrocardiograms showed left axis deviation in nine of the 13 cases studied. Vectorcardiographic findings, though variable and available in only seven cases, tended to show a narrow horizontal plane QRS vector loop in patients with restricted pulmonary blood flow and a wide loop in those with increased pulmonary flow.
The clinical, laboratory, and pathologic findings are reported and the differential diagnosis and the profile of the condition are considered.
Echocardiography in Coexisting Hypertrophic Subaortic Stenosis and Fixed Left Ventricular Outflow Obstruction
Authors: CHUNG KYUNG J. , MANNING JAMES A. , GRAMIAK RAYMOND 
Published: June 2012

Echocardiographic study was done on four pediatric patients with coexisting hypertrophic subaortic stenosis (HSS) and fixed left ventricular outflow (LVO) obstruction. One had valvar aortic stenosis, two had discrete subaortic stenosis and one had coarctation of the aorta. Preoperatively, HSS was not suspected in any of these patients because of the classical findings of fixed LVO obstruction. The echocardiographic examination revealed an abnormal systolic anterior movement (SAM) of the anterior mitral leaflet with ventricular septal hypertrophy in all, but these findings were overlooked or thought to be related to a subvalvar diaphragm. One or two years after the surgical removal of their fixed obstruction, all showed clinical pictures of HSS. Postoperative echocardiographic examination showed an abnormal SAM with asymmetrical septal hypertrophy, and cardiac catheterization revealed mild to severe degrees of resting pressure gradients across LVO tracts. Amyl nitrite inhalation produced a more prominent SAM with increasing pressure gradient, and angiotensin infusion abolished the SAM and reduced the pressure gradient.
From our present study, echocardiography has the potential for identification of HSS coexisting with a fixed LVO obstruction. We recommend that all patients with LVO obstruction have an echocardiographic examination along with pharmacological testing. The demonstration of an unusually thickened ventricular septum and especially, abnormal SAM of the mitral valve would require careful evaluation of left heart hemodynamics and the determination of the level of the major obstruction during cardiac catheterization for pre and postoperative management.
Effect of Propranolol on Oxygen Binding to Hemoglobin
In Vitro
and
In Vivo
Authors: LICHTMAN MARSHALL A. , COHEN JULES , MURPHY MARION S. , KEARNEY ELIZABETH A. , WHITBECK APRIL A. 
Published: June 2012

We have shown that propranolol reduces oxygen binding by hemoglobin in intact red cells by increasing the selective permeability of the red cell membrane resulting in an exodus of potassium, chloride, and water. The latter effects result in a new distribution of hydrogen ion between cell and plasma, and thereby a reduction in red cell pH. The reduction in pH can fully explain the change in hemoglobin's affinity for oxygen based on the Bohr effect. Either D- or DL-propranolol can produce the change in red cell pH and oxygen binding by hemoglobin. The drug action on permeability is not prevented by epinephrine, although it is by chlorbutanol. Hence, the membrane action of propranolol does not appear to be related to its activity as a beta-adrenergic receptor blocking agent.
Propranolol produced a marked alteration in red cell shape as well as in hydration (hypovolumic stomatocytes). The two effects were separable since dehydration of the cell by the addition of sucrose to plasma did not result in stomatocytes and chlorbutanol blocked the enhancement of permeability of the red cell membrane by propranolol without preventing the shape change (isovolumic stomatocytes). This suggests that propranolol may have two separate sites of membrane interaction.

Propranolol (10 to 360 mg) administered to human subjects did not affect hemoglobin-oxygen affinity. This is explained by the fact that the concentration in blood after such doses is nearly 4,000 to 100-fold lower than that required to achieve changes in blood
in vitro.
Evaluation of Left Ventricular Performance
Authors: BENZING GEORGE , STOCKERT JAMES , NAVE EDWIN , KAPLAN SAMUEL 
Published: June 2012

In the first part of the study, the influence of changes in preload and afterload on mean circumferential fiber shortening velocity, Vcf, was investigated in the absence of any extrinsic cause for change in the contractile state of the left ventricle (LV) of seven dogs. In five of seven dogs in which afterload was controlled and contractility was unchanged, there was a significant negative correlation between LV end-diastolic pressure and mean Vcf expressed in circumferences per second (
r
= –.88 to –.97). In one dog there was a positive correlation (
r
= +0.847) and in another dog there was no significant correlation. Correlation as a group was poor.

In five of the above seven dogs in which afterload was decreased from a control level while preload was controlled and contractility was not extrinsically altered, mean Vcf increased in all instances. Because of the influence of afterload on Vcf increased in all instances. Because of the influence of afterload on Vcf and the inconsistent relation between Vcf and preload, we controlled preload and afterload during assessment of Vcf in reflecting a change of LV contractility.
Since mean left ventricular hydraulic output power, MLVP, quantitates practically all of the mechanical power of the left ventricular musculature, MLVP was utilized to represent the contractile state of the left ventricle under conditions in which preload and afterload were controlled. Mean and peak Vcf, Vcf at peak tension, extent of circumferential fiber shortening, and peak tension were compared with MLVP to test their usefulness in reflecting a change in the contractile state of the LV.
Twenty dogs were divided into four groups of five each. Group I was exposed to cardiopulmonary bypass alone. Dogs of groups II, III, and IV were exposed to a total of 45 minutes of myocardial ischemia during bypass. After bypass, groups I, II, III and IV retained an average of 89.3, 79.9, 82.5 and 69.2% of the control or original mean Vcf, and 87.1, 63.9, 53.4 and 33.5% of the control MLVP, respectively. Although an effect of ischemia was detected by changes of peak tension and extent of fiber shortening, the statistical evidence was less satisfactory than observed for MLVP. It was concluded that mean Vcf, peak Vcf, and Vcf at peak tension are inadequate indices to detect acute changes in the contractile state of the LV produced by prior myocardial ischemia. These same changes in contractility are readily determined by MLVP.
The Missing Waveform Information in the Orthogonal Electrocardiogram (Frank Leads)
Authors: KORNREICH F. , BLOCK P. , BRISMEE D. 
Published: June 2012

A new lead system recording nine surface ECGs was found capable of resynthesizing in each patient all the QRS waveforms recorded on the thoracic surface. Observations were made in 416 patients: 150 normal (N) individuals, 95 patients with left ventricular hypertrophy (LVH), 97 patients with right ventricular hypertrophy (RVH), and 74 patients with biventricular hypertrophy (BVH). After time-normalization and division of the nine waveforms into eight equal parts, 72 variables were determined for each patient. Recordings from Frank XYZ leads were also available for each subject. After time-normalization and division in eight equal parts, 24 variables were obtained from Frank lead recordings in each individual.
The 72 variables from the new system and 24 variables from the Frank leads were then submitted to multivariate statistical procedures in order to differentiate BVH from N, LVH, and RVH. Four parameters were finally retained — for both the 9-lead system and the Frank leads — as the best discriminators for the separation of BVH from normal, BVH from LVH, and BVH from RVH. The diagnostic performances, defined as ½ (specificity + sensitivity), were 93.5%, 85%, and 81%, respectively, for the 9-lead system and 88.5%, 69%, and 75% for the Frank leads. The repeatability of the results was tested on independent control samples and found reasonable.
The limited clinical use of independent pairwise comparisons is discussed and the alternative of stepwise pairwise comparisons following a decision tree is proposed. Some deterioration in the final classification is noticed; the recognition rates are 90% for normal, 79% for LVH, 75% for RVH and 73% for BVH (average 79%) with the 9-lead system, and 90% for N, 55% for LVH, 46% for RVH and 59% for BVH (average 62%) with the Frank leads.
The Treatment of Recurrent Ventricular Tachycardia with Bilateral Cervico-Thoracic Sympathetic-Ganglionectomy
Authors: LLOYD RICHARD , OKADA ROBERT , STAGG JAMES , ANDERSON ROBERT , HATTLER BRACK , MARCUS FRANK 
Published: June 2012

Two patients had bilateral cervico-thoracic sympatho-ganglionectomy for treatment of disabling symptoms due to refractory ventricular tachycardia. In both patients treatment with antiarrhythmic drugs singly, in combination, or together with pacemaker overdrive had been ineffective in controlling this arrhythmia. Both patients had normal coronary arteriograms.
Bilateral thoracic sympathectomy appears to facilitate medical management of ventricular tachycardia in selected patients who are refractory to the usual medical treatment.
Sudden Death as a Complication of Anomalous Left Coronary Origin From the Anterior Sinus of Valsalva
Authors: CHEITLIN MELVIN D. , DE CASTRO CARLOS M. , MCALLISTER HUGH A. 
Published: June 2012

Both coronary arteries arising as a single or double vessel from the same sinus of Valsalva has been considered a minor congenital anomaly not affecting longevity. There are rare case reports in the literature of sudden death in young males with this anomaly of coronary origin. We have reviewed 51 such cases from the Armed Forces Institute of Pathology congenital heart disease accessions. There were 33 patients in whom both coronaries arose from the anterior sinus of Valsalva either as a single or double vessel and 18 in whom they arose from the left coronary sinus of Valsalva. Out of the 33 patients in whom the coronaries arose from the anterior sinus of Valsalva, 9 (27.3%) died sudden, unexplained deaths. There were no sudden unexplained deaths among the patients in whom both coronaries arose from the left sinus of Valsalva. It is evident that where the left coronary artery does not pass acutely posterior and leftward between the pulmonary artery and the aorta there is no risk of sudden death. All patients who died suddenly were male. The suggested mechanism for sudden death in these cases is that the acute leftward passage of the coronary artery along the aortic wall causes the entrance into the left coronary svstem to be slit-like. Under circumstances of increased cardiac activity with increased expansion of the pulmonary artery and aorta with exercise, there is stretching of the left coronary artery and a flap-like closure of the orifice of the left coronary with sudden, fatal myocardial ischemia.
We also present the first case where this anomaly was recognized in a 14-year-old boy and a surgical attempt was made to correct the problem by creating a non-collapsible funnel-like opening into the left coronary artery.
Atherosclerosis Complicating Chronic Hypertension
Authors: DUSTAN HARRIET P. 
Published: June 2012

The accelerating effect of hypertension on atherogenesis in the aorta and iliofemoral and coronary arteries is presented here as a graded function of elevated intraarterial pressure. Predilection of the abdominal aorta and iliofemoral arteries for atherosclerosis can be explained on the basis of pressure augmentation by reflected pressure pulse waves and the increase in hydrostatic pressure that is produced by standing. Wave reflection is intensified by vasoconstriction, which is a characteristic not only of hypertension but also occurs with upright posture. Standing also raises the hydrostatic pressure of blood in vessels below heart level. Coronary atherosclerosis seems likely to relate to the fact that the coronary vessels are located in an area of high pressure in the arterial system and that their intramyocardial branches are normally completely occluded during systole — a condition which could be accompanied by subtle differences in the pressure-volume characteristics of the epicardial vessels.
Evidence is presented from actuarial statistics, epidemiologic studies, and laboratory experiments to indicate that the level of arterial pressure has a measurable effect on the metabolism of arterial smooth muscle cells. Thus arterial pressure is viewed as having a metabolic determinant role in addition to its vital role in the circulation of blood.
Myocardial Necrosis from Direct Current Countershock
Authors: DAHL CHARLES F. , EWY GORDON A. , WARNER E. D. , THOMAS EVAN D. 
Published: June 2012

The effect of varying both paddle electrode size and the time interval between direct current countershock on myocardial necrosis was studied. Forty-two dogs were divided into seven groups of six dogs each. All dogs were given ten consecutive, 240 watt-second countershocks (delivered energy into a 50 ohm load). Three groups were shocked with paddle electrode diameters of 8.0 cm (standard electrodes), two groups with paddle electrode diameters of 12.8 cm (large electrodes), and two groups with paddle electrode diameters of 4.3 cm (small electrodes). The time intervals between discharges in the groups shocked with the standard electrodes were 15 seconds, one minute, and three minutes. The time interval between discharges in the groups shocked with small and large electrodes was 15 seconds and three minutes. Myocardial necrosis was quantitated by precordial electrocardiographic mapping recorded minutes after, and by gross and microscopic examination of the hearts four days after direct current countershock.
When the time interval between discharges was shorter, myocardial necrosis was greater. When the time interval between discharges was constant, more necrosis was produced with smaller-sized paddle electrodes. It is concluded that large paddle electrodes should be used for delivering direct current countershocks, and that during elective cardioversion, consecutive discharges should be delivered at time intervals greater than three minutes.
Maximum Treadmill Exercise Electrocardiography in Female Patients
Authors: LINHART JOSEPH W. , LAWS JAMES G. , SATINSKY JONATHAN D. 
Published: June 2012

Exercise testing has become standardized for the diagnostic and functional evaluation of male patients but little data is available regarding its specificity and sensitivity in the female. Therefore, maximum treadmill exercise (Bruce protocol) was performed on 98 consecutive females and compared to coronary arteriography. Using 50% obstruction as indicating coronary artery disease and 1 mm ST-segment depression (horizontal or downsloping) as positive for ischemia, 24 patients had coronary artery disease with seven false-negative results (sensitivity = 71%) and 74 patients had no coronary artery disease with 16 false-positive responses (specificity = 78%).
Five of seven false-negative tests were in patients with single-vessel disease. Eleven of 16 false-positive responses were in patients on digitalis, diazepam, or methyldopa. In 39 patients on no drug therapy except for nitroglycerin there were no false negatives and only four false-positive tests. There were no false negatives and only two false-positive tests in 34 patients with normal resting electrocardiograms. Only one of 18 patients with both normal resting electrocardiograms and on no drug therapy had a false-positive test result. Eleven false-positive and seven false-negative results occurred in 40 patients with both an abnormal resting electrocardiogram and associated drug therapy.
The exercise electrocardiographic response in female patients is similar to the male when patients with resting electrocardiographic abnormalities and concomitant drug therapy are eliminated.
Vectorcardiography
Authors: BURCH G. E. , ABILDSKOV J. A. , CRONVICH J. A. 
Published: June 2012

Both theoretic considerations and actual studies suggest that spatial vectorcardiography will eventually have practical applications. It is likely to furnish clinically useful information in addition to that provided by conventional electrocardiography. This is a statement of probability, however, and has not yet been established, nor have the circumstances in which it may apply yet been defined. For this reason the current status of vectorcardiography is properly that of a research method, not yet suitable for general clinical application.
Many technics have been employed to obtain the vectorcardiogram. The graphic derivation of vectorcardiograms from electrocardiographic leads is of historic interest only. The use of the cathode ray oscilloscope with suitable amplifiers is the method of choice. Many modifications of technic, such as recording on moving film, recording of successive complexes, and stereoscopic recording, are possible with the use of the cathode ray oscilloscope. It is not yet apparent which recording technic will prove to be most informative, so that studies with a variety of technics seem advisable.

Several systems of electrode placement have been advocated for obtaining the spatial vectorcardiogram. Since the application of any geometric reference frame to the human body necessitates several assumptions which are not actually true, it appears that the choice among reference frames cannot be made on the basis of their intrinsic validity. We are of the opinion that the equilateral tetrahedron introduced by Wilson and associates
12
offers advantages over other reference frames because:

(1) Only one electrode is necessary in addition to those employed to obtain the standard electrocardiographic leads.
(2) Electrodes are easily applied, and their positions are readily reproducible.
(3) The knowledge already available from experience with the standard leads of the electrocardiogram may be applied to spatial vectoreardiography.
(4) Each of the four surfaces defined by the electrode positions is an equilateral triangle.
(5) The disadvantages of this reference system are common to those of other proposed reference frames.
Variations of the spatial vectorcardiogram in normal man and in man with a variety of disease states have been studied by several groups of investigators with a variety of technics. These studies are of considerable importance, but as yet nearly all lack pathologic confirmation of the presence, site and size of suspected lesions. These data must be obtained and thoroughly correlated with the vectorcardiogram before vectorcardiography can be employed with certainty in general clinical practice.
A. B. Marx’sSonatenform
Authors: Uribe Patrick Wood 
Published: June 2012

It is to A. B. Marx that we owe the first extended discussion of sonata form and a conception of it that has survived in classrooms and rehearsal halls to this day. At the same time, Marx’s Sonatenform and his treatment of it are beset with what seem to be serious flaws, chief among which is the absence of a single example of a complete movement from existing music that embodies the form.Taking the perceived weaknesses of his discussion as a starting point, I argue that they are in fact the result of an ambitious and sophisticated approach to form, which depends on a more thorough understanding of the larger body of Marx’s theory of forms, and specifically of the forms immediately preceding sonata form in Marx’s discussion.As a consequence, it is possible not only to reassess the apparent shortcomings of Marx’s original formulation but also to see sonata form itself less as a mere codification of formal elements than as a means of coming to terms with the music it considers.
Effect of Reservoir Temperature and Pressure on Relative Permeability
Authors: Xiao G. , Jingjing M. , Jiudi L. , Yang H. , Haiying W. 
Published: June 2012

Abstract
Relative permeability is a critical parameter for evaluation of gas reservoir performances. Earlier works have indicated that relative permeabilities are markedly dependent on pore geometry, wettability, fluid saturation, saturation history, reservoir temperature, reservoir pressure, overburden pressure, rock types, porosity and permeability types. Some literatures have reported effect of reservoir temperature, reservoir pressure, overburden pressure on relative permeability. Because we are subjected to experiment conditions, it is very difficult for Dabei naturally fractured gas reservoir to measure relative permeability under 120 MPa abnormal high pressure and 145 Centigrade high temperature. In this paper, relative permeability of 12 cores without fracture and 3 cores with fracture during displacement of water by gas and displacement of gas by water in Dabei naturally fractured gas reservoirs under lower pressure and room temperature was measured. The results indicated that relative permeability in the process of displacement of water by gas is obviously different from that in the process of displacement of gas by water. Gas-water relative permeabilities of rock with fracture are higher than that of rock without fracture. In order to evaluate effect of abnormal high pressure and high temperature on relative permeability. A transformation model of gas-water relative permeability from experiment conditions to reservoir conditions was built up. A high temperature and high pressure wells for example, the effect of temperature and pressure on gas-water permeability was analog calculated, which the result indicated that water relative permeability cannot be effected by temperature and pressure, but gas relative permeability is. While gas relative permeability measured at experiment temperature and pressure which is beyond 10 times difference than the high pressure and high temperature at reservoir condition. It is suggested that it is unadvisable to predict gas reservoir performance by using gas-water relative permeability measured at experiment conditions.