bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiovascular Function in Shock
Authors: CAREY JOSEPH S. , BROWN ROBERT S. , MOHR PATRICIA A. , MONSON DAVID O. , YAO SEE TAO , SHOEMAKER WILLIAM C. 
Published: June 2012

Hemodynamic responses to volume loading with infusion of dextran-40 and myocardial stimulation with isoproterenol in 23 patients in shock from hemorrhage, trauma, or sepsis, and 10 healthy controls were studied. Responses of the control were moderate to dextran and marked to isoproterenol. Shock patients were divided into three groups according to the response of the cardiac index to dextran-40: group I, >50% increase; group II, 15 to 50% increase; group III, <15% increase or a decrease. The central venous pressure of patients who responded to dextran (group I) generally rose moderately and that of those who failed to respond (group III) increased without improvement of cardiac index or stroke index, suggesting myocardial failure. Group II showed cardiac improvement at the expense of marked increase in venous pressure, suggesting relative cardiac insufficiency.
Group I failed to respond to isoproterenol infusion, indicating that circulatory failure primarily resulted from failure of venous return. All group III patients responded markedly to isoproterenol. It is concluded that a significant number of patients in shock from hemorrhage, trauma, and sepsis exhibit signs of cardiac insufficiency. The ability of these hearts to respond to isoproterenol suggests that depletion or altered metabolism of endogenous catecholamines in part underlies this insufficiency. Further-more, it is suggested that cardiac insufficiency may contribute to the death of a significant number of patients with severe hemorrhagic and septic shock.
Correlation of Hemodynamic Data and Pulmonary Angiography in Mitral Stenosis
Authors: SIDD JAMES J. , DERVAN ROSEMARY A. , LELAND O. STEVENS , SASAHARA ARTHUR A. 
Published: June 2012

The abnormalities of pulmonary arterial blood supply in mitral stenosis, consisting primarily of constriction of lower lobe vessels with resultant upper lobe preferential flow, was assessed by means of pulmonary angiography in 30 patients with mitral stenosis uncomplicated by other cardiac diseases. The abnormalities in blood flow correlated best with both the pulmonay artery pressure and the pulmonary arteriolar resistance, and only reasonably well with the area of the mitral valve and the pulmonary capillary wedge pressure. It is suggested that the reversal of the normal lower lung field preferential blood flow in mitral stenosis is primarily a function of pulmonary artery hypertension due to increased pulmonary arteriolar resistance.
Similarly, the width of the right main pulmonary artery as measured on pulmonary angiograms correlated well with both the pulmonary artery pressure and pulmonary arteriolar resistance and less well with the area of the mitral valve. Pulmonary artery size in mitral stenosis is most likely a function of the severity of the pulmonary arteriolar resistance as reflected in the pulmonary artery pressure.
Histochemical Studies of the Myocardium and Conduction System in Acquired Iron-Storage Disease
Authors: SCHELLHAMMER PAUL F. , ENGLE MARY ALLEN , HAGSTROM JACK W. C. 
Published: June 2012

The myocardium, all parts of the conduction system, and the S-A node contained iron in six patients with acquired iron-storage disease. The nerve fibers and ganglia contained negligible amounts. No correlation was demonstrated between the amount of histochemically demonstrated iron in the myocardium and conduction system, or the amount of transfused iron, or the amount of quantitatively analyzed myocardial iron and the presence of antemortem arrhythmias and conduction disturbances. The degree of scarring in the S-A node, A-V node, and bundle of His did not parallel the density of iron deposits in these structures.
These observations support the theory that factors other than iron alone are responsible for the cardiac rhythm and conduction abnormalities associated with iron-storage disease.
The Electrophysiological Properties of Diphenylhydantoin Sodium as Compared to Procaine Amide in the Normal and Digitalis-Intoxicated Heart
Authors: HELFANT RICHARD H. , SCHERLAG BENJAMIN J. , DAMATO ANTHONY N. 
Published: June 2012

The effects of diphenylhydantoin sodium (Dilantin) on ventricular automaticity, intraventricular conduction, atrioventricular (A-V) conduction, and sinus rate have been determined in the digitalis-intoxicated and normal heart. These effects have been compared with procaine amide. Diphenylhydantoin sodium depresses ventricular automaticity and enhances A-V conduction while having little or no effect on intraventricular conduction or sinus rate. Procaine amide differed from diphenylhydantoin sodium in that it caused depression of both A-V and the intraventricular conduction, as well as slowing of the sinus rate.
The results indicate that the electrophysiological properties of diphenylhydantoin sodium make it superior to procaine amide in the treatment of digitalis toxicity. Both diphenylhydantoin sodium and procaine amide can suppress digitalis arrhythmias due to enhanced automaticity, but procaine amide may promote "re-entry" arrhythmias by potentiating the intraventricular conduction defect caused by the glycoside. In addition, diphenylhydantoin sodium appears to antagonize the action of digitalis on the A-V node, while procaine amide increases the digitalis-induced A-V block. It is concluded that the electrophysiological properties of diphenylhydantoin sodium make it an excellent agent in treating digitalis-induced arrhythmias.
Measurement of Pulmonary Edema in Valvular Heart Disease
Authors: MCCREDIE MICHAEL 
Published: June 2012

Pulmonary extravascular fluid volume (PEV) has been estimated by using a double isotope technique in nine normal subjects and 45 patients with valvular heart disease. The method was reproducible, the standard deviation being±15.2 ml/m
2
, or 11.2% of the mean.

Groups of patients with aortic and mitral valve disease had significantly higher values of PEV than normal persons; some patients with pulmonary stenosis had subnormal values. There was a relationship between PEV and the severity of dyspnea; all patients with an abnormally high PEV were class II or worse. Of the 18 patients with abnormally high PEV, only seven had radiological evidence of chronic pulmonary edema.
PEV was independent of blood flow but was clearly related to the level of pulmonary intravascular pressure. PEV was only significantly elevated if left atrial mean pressure exceeded 12 mm Hg and was invariably raised if it exceeded 25 mm Hg. No relationship of PEV to pulmonary vascular resistance was evident in this study.
Angiographic Anatomy of the Left Ventricle and Mitral Valve in Idiopathic Hypertrophic Subaortic Stenosis
Authors: SIMON ALLAN L. , ROSS JOHN , GAULT JAMES H. 
Published: June 2012

The angiographic features of the left ventricle were examined in patients with idiopathic hypertrophic subaortic stenosis who had clinical and hemodynamic evidence of obstruction. Of 36 combined hemodynamic and angiographic studies considered to be technically satisfactory, 33 showed a characteristic combination of abnormalities. In the frontal projection in systole, a linear radiolucent area extended across the left ventricular outflow tract 2 to 2.5 cm below the aortic annulus, at a level corresponding to the site of intraventricular pressure change. In the left oblique and lateral projections, the mitral leaflets did not swing posteriorly in a normal fashion, but projected into the outflow tract during mid and late systole. The radiolucent line, seen in the frontal views, was considered to represent contact of the leading edge of the leaflet with the hypertrophied muscular interventricular septum. The jet of mitral regurgitation, when present, was seen immediately below the anterior mitral leaflet.
Severe hypertrophy was also seen to involve the inferior portion of the muscular septum, causing displacement of the papillary muscles superiorly and to the left. This maldirection of the papillary muscles was postulated to cause abnormal traction on the chordae tendineae and to prevent normal movement of the mitral leaflets away from the septum during systole. The leaflets, held in the outflow tract, form the posterior component of the obstruction, the anterolateral component of which results from severe, asymmetric septal hypertrophy. It was proposed that this mechanism plays an important part in producing the intraventricular pressure gradient in many patients with idiopathic hypertrophic subaortic stenosis.
Arterial Pressure Responses to Discontinuing Antihypertensive Drugs
Authors: DUSTAN HARRIET P. , PAGE IRVINE H. , TARAZI ROBERT C. , FROHLICH EDWARD D. 
Published: June 2012

A wide spectrum of arterial pressure responses to discontinuing long-term antihypertensive drug treatment was found in 65 patients. In five, spontaneous pressure variations prevented judging effects of drug discontinuance. Of the remaining 60, pressure returned to pretreatment levels in 21, and rose toward control levels in 37; while in two, diastolic hypertension did not reappear in more than 8 years. Rate of rise of arterial pressure seemed related to type of hypertension and to height of diastolic pressure and severity of vascular disease before treatment. In six of nine patients who had had malignant hypertension and six of nine with renal arterial disease, pressure rose promptly and treatment was restarted within a month. Among essential hypertensive patients, those who remained off treatment for 2 to 6 months had significantly lower pretreatment pressure than those whose hypertension returned in less than 2 months. The two whose diastolic hypertension seemed "cured" had no distinguishing features.
These results suggest that most hypertensive patients require continuous treatment for good pressure control; downward resetting of pressure by treatment is rare.
The Coronary Arteries in Coarctation of the Aorta
Authors: VLODAVER ZEEV , NEUFELD HENRY N. 
Published: June 2012

The histological changes found in the coronary arteries in 15 patients with coarctation of the aorta have been described. Qualitative and quantitative studies were performed and the results compared with the findings of a matched control group of patients without heart disease.
Severe changes in the intima during early life and even the severe atheroma which appears in young persons are considered to be a reaction to coronary hypertension. The striking thickening of the media in the coronary arteries is also thought to be a reaction to the altered hemodynamic forces.
In coarctation of the aorta the coronary arteries are of greater than normal capacity, and it is suggested that this histological feature parallels the increased metabolic requirements of the left ventricle.
Operative Treatment in Idiopathic Hypertrophic Subaortic Stenosis
Authors: MORROW ANDREW G. , FOGARTY THOMAS J. , HANNAH HAMNER , BRAUNWALD EUGENE 
Published: June 2012

Operations designed to relieve obstruction to left ventricular outflow were carried out in 25 patients with idiopathic hypertrophic subaortic stenosis (IHSS). All of the patients were symptomatic and 23 were in functional classes III or IV. Preoperatively, a systolic pressure gradient within the left ventricle was demonstrated in every patient (average, 102 mm Hg), and the average left ventricular end-diastolic pressure was 19 mm Hg. Six patients had pulmonary hypertension.
During cardiopulmonary bypass, the outflow tract of the left ventricle was exposed through an aortotomy. In five early patients only ventriculomyotomy was carried out, but in all subsequent operations myotomy was combined with a limited resection of the hypertrophied muscular tissue. One patient died, apparently of arrhythmia, on the eighth postoperative day, and another 8 months after operation following cerebral thrombosis. In two other patients complete heart block was produced, and they have implanted pacemakers.
Twenty-one of the 23 surviving patients have been followed for periods of 1 to 8 years; 15 are asymptomatic (class I). Six patients have mild residual limitation of activity (class II), but none has had congestive heart failure or syncope postoperatively, and only one experiences significant angina.
Left heart catheterization has been performed on one or more occasions after operation in all 21 patients. In 19, no systolic pressure gradient was evident within the left ventricle under resting conditions, and in the other two patients, gradients of 11 and 8 mm Hg were recorded. The left ventricular end-diastolic pressure was lower in 16 of the 17 patients in whom it was abnormally elevated preoperatively, and in nine of them it was normal. The pulmonary arterial pressure was normal postoperatively in all patients who had severe pulmonary hypertension.
Control of Postcardiac Surgical Tachycardias with Propranolol
Authors: MATLOFF JACK M. , WOLFSON STEVEN , GORLIN RICHARD , HARKEN DWIGHT E. 
Published: June 2012

Twenty-two patients manifesting arrhythmias refractory to conventional therapy have been treated with propranolol 1 to 19 days after cardiac surgery.
Rapid control of ventricular response to supraventricular arrhythmias, abolition of ventricular irritability caused by digitalis excess, and frequent conversion of acute atrial fibrillation or flutter were attained.
Control of the arrhythmia was achieved in all but one instance. No significant side effects were encountered, although the potential risks of propranolol are stressed.
Propranolol appears to fill specific needs unsatisfied by standard therapy for arrhythmias developing after cardiac surgery.
Early Functional and Ultrastructural Recovery of Canine Cadaver Hearts
Authors: COPELAND JACK , KOSEK JON C. , HURLEY EDWARD J. 
Published: June 2012

Simulation of sudden death in a potential heart graft donor was accomplished by producing acute anoxic arrest in canine hearts that were then maintained at cadaver temperature for periods of from 15 to 60 minutes prior to reperfusion with oxygenated blood. Functional recovery of reperfused hearts measured by contractile force was more rapid for hearts that had undergone shorter periods of anoxic arrest. The rates of recovery were nearly identical within the group for 15 to 25 minutes and for 30 to 45 minutes of anoxic arrest, but not for the 60-minute anoxic arrest group in which two of four hearts made no recovery at all.
Ultrastructural reactions to anoxic arrest were evident at 15 minutes and found to progress in a predictable manner as the duration of anoxia increased. Changes occurring during anoxic periods of up to 30 minutes were for the most part reversed within 1 hour of perfusion during which time characteristic nuclear, cytoplasmic, and mitochondrial "recovery patterns" were encountered. With a "pump-dog" preparation, these reperfused hearts were well kept for up to 7 hours. Anoxic arrest of 45 minutes or more produced ultrastructural changes that were less consistently reversed by reperfusion of 1 hour. The sensitivity of mitochondrial structure to anoxic arrest and reperfusion was demonstrated, and suggested that irreversible cell damage (i.e., cell death) in anoxia is due to mitochondrial failure. The techniques of perfusion and ultrastructural sampling employed in these experiments should prove useful in studying the effects of hypothermia, drug application and other measures in the preservation and restoration of isolated hearts.
Iliofemoral Venous Thrombectomy
Authors: SMITH GARDNER W. 
Published: June 2012

Experience with iliofemoral venous thrombectomy in 45 cases has been reviewed. The indications for this procedure have been presented, and only two absolute contraindications are recognized. Certain aspects of surgical technique and of postoperative care have been discussed, with emphasis on the use of local anesthesia, the balloon catheter, and early postoperative ambulation.
Results indicate that iliofemoral venous thrombectomy does relieve early morbidity and appears to be as successful as nonoperative management in the prevention of pulmonary embolism. Clinical improvement has been achieved in 76% of the entire group, and these results are influenced by both the preoperative duration of symptoms and the degree of success in removing the thrombus at operation. Of particular significance is a group of 14 patients followed for 2 or more years, only 14% of whom were afflicted by the sequelae of deep venous insufficiency. This finding provides encouraging support for the thesis that iliofemoral venous thrombectomy may ameliorate the late postphlebitic sequelae of deep venous thrombosis.
Effects of Acetylcholine on Regional Pulmonary Blood Flow in Patients with Mitral Stenosis
Authors: GLAZIER JON B. , DOLLERY COLIN T. , HUGHES JOHN M. B. 
Published: June 2012

The effect of acetylcholine was studied on the region of increased vascular resistance at the lung bases in patients with mitral stenosis. The patients had moderate elevations of pulmonary artery pressure.
The distribution of blood flow and ventilation were measured in both lungs of 10 patients using radioactive xenon-133 and a scanning technique. Acetylcholine was then infused into one main pulmonary artery, and the distribution of blood flow and ventilation were measured again. One lung served as a control during the drug infusion. There was a small but significant increase in perfusion to the dependent lung zone during the drug infusion without a change in pulmonary artery pressure indicating localized vasodilatation. Relative underperfusion was still present during the acetylcholine administration which indicated that increased vasomotor tone was not the principal pathophysiological mechanism for the increased vascular resistance. There was a decrease in ventilation to the lower zone of the lung receiving acetylcholine.
Correlation of Myocardial Ultrastructure and Function
Authors: SONNENBLICK EDMUND H. 
Published: June 2012

The electron microscopic structure of heart muscle and the ultrastructural basis of cardiac contraction have been reviewed. The relation between muscle length and developed tension has been explained in terms of the structure of the sarcomere, which is the basic unit of contraction. Using the derived length-tension curve of the sarcomere, developed tension has been attributed to the overlap of thick and thin filaments within the sarcomere, lending support to the "sliding" mechanism in heart muscle.
It has been shown that initial sarcomere length is a function of ventricular filling pressure and that this relation explains the normal limits of the heart as a pump, including: (1) the Starling mechanism whereby increased diastolic volume (EDV) engenders an increased stroke volume (SV), (2) the upper limits to ventricular filling pressure and volume, and (3) the normal range to the ventricular ejection fraction (SV/EDV). Further, ultrastructure helps to define the processes which occur with acute and chronic ventricular dilatation. In this regard, the importance of sarcomere dispersion and "fiber slippage," which may lead to disordered ventricular function, have been discussed.
Disturbances in Atrial Rhythm and Conduction Following the Surgical Creation of an Atrial Septal Defect by the Blalock-Hanlon Technique
Authors: HAMILTON SANDRA D. , BARTLEY THOMAS D. , MILLER ROBERT H. , SCHIEBLER GEROLD L. , MARRIOTT HENRY J. L. 
Published: June 2012

Disturbances in atrial conduction or rhythm, or both, were found in 16 of 27 patients undergoing the surgical creation of an atrial septal defect by the Blalock-Hanlon technique. These included P-wave aberrations of intra-atrial block and ectopic atrial rhythm, A-V rhythm, A-V dissociation, sinus bradycardia, atrial flutter, escapecapture bigeminy, and atrial premature beats. Some of these were transient and occurred within 2 weeks after surgery. It seems likely that tissue trauma engendered by the clamp and resection of the atrial septum with possible injury to the internodal conducting pathways may be the genesis of these early postoperative disturbances. Of the eight cases with transient disturbances, six occurred in this period.
Later changes, such as intra-atrial block, sinus bradycardia, and atrial flutter, may be atttributed to changes in atrial size secondary to the postoperative pathophysiology. Digitalis intoxication and congestive heart failure cannot be excluded as contributory factors in either the early or the late disturbances.
It was not possible to correlate the incidence and nature of these disturbances with morbidity and mortality. In such severely ill, cyanotic infants, irregularities, however slight, may have altered cardiac function significantly and contributed to their deaths.
Endocardial Electrograms from Pacemaker Catheters
Authors: GORDON ALVIN J. , VAGUEIRO MARIA CELESTE , BAROLD S. SERGE 
Published: June 2012

Proper placement of pacemaker catheters can be facilitated by recording endocardial electrograms from the catheters. These electrograms are also helpful in the investigation of pacemaker failure. Endocardial contact is indicated by S-T segment elevation. When bipolar catheters are used, these "contact currents" may be visible in electrograms from the tip or ring electrodes, or both.
Right ventricular cavity electrograms are characterized by their high voltage and are influenced by intraventricular conduction defects and acute myocardial infarction. Serial changes have been described indicating myocardial injury, infarction, and healing in the area underlying the catheter tip.
Constrictive Pericarditis
Authors: SOMERVILLE WALTER 
Published: June 2012

Patients with untreated constrictive pericarditis sooner or later have ascites, edema, and pleural effusions. Unless these are treated, the patient soon becomes bedridden.
Treatment with a low-sodium diet, diuretics, and aspiration often allows a patient to live a semi-invalid life for 5 to 15 years and occasionally to survive to old age. However, the general tendency is toward gradual deterioration despite treatment. The course in children and young adults is more rapid and the effects of medical treatment less effective.
Pericardiectomy abolishes or greatly improves symptoms and signs in 60 to 85% of patients; the benefits are long lasting; and life expectation is increased. The operative mortality is in the range of 4 to 20%. Persistence of symptoms and signs after operation is attributable to one of the following factors: delayed hemodynamic adjustment, imperfect surgical relief, or myocardial changes. These changes may be the result of myocardial atrophy, other degenerative myopathies, or associated disease.
After an effective pericardiectomy, the hemodynamic fault may be completely corrected, but some residual abnormality can persist with symptomatic improvement. The electrocardiogram may improve, become completely normal, or remain unchanged; while electrocardiographic improvement is invariably associated with clinical improvement, the latter may occur despite persistence of an abnormal electrocardiogram. The heart size usually diminishes. Protein-losing gastroenteropathy is completely cured or greatly improved.