bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Frontal Plane Vectorcardiogram in Old Inferior Myocardial Infarction
Authors: YOUNG ELIOT , LEVINE HAROLD D. , VOKONAS PANTEL S. , KEMP HARVEY G. , WILLIAMS RICHARD A. , GORLIN RICHARD 
Published: June 2012

The mid-to-late part of the frontal plane QRS loop (Frank lead system) of 150 consecutive subjects with an old inferior myocardial infarction was analyzed. During the acute episode all cases had to satisfy Myers' classical ECG criteria for the diagnosis. The vectorcardiogram was recorded months to years later.
As a result of this analysis and in order to prevent overlap with values found in 450 normal control subjects, four VCG criteria are proposed for this diagnosis.
The VCGs of 75 of the 150 patients fulfilled one or more of the four VCG criteria. The ECG, done at the time of VCG, satisfied Myers' or Goldberger's criteria or both criteria in 33 of these 75 patients, and an additional 24 of the 150 fulfilled either or both of these ECG criteria but had none of the four VCG criteria.
Among 131 consecutively catheterized subjects who had significant disease of one or more major coronary arteries, 40 fulfilled one or more of the VCG criteria. Thirty-six of the 40 showed significant stenosis of at least the right coronary artery, and the other four, of at least the left circumflex but not of the right coronary artery. Six of these 40 fulfilled Myers' or Goldberger's criteria. Five of the 131 fulfilled either or both of these ECG criteria but none of the four VCG criteria.
The Regulation of Cerebral Blood Circulation in Subclavian Steal Syndrome
Authors: SOLTI FERENC , ISKUM MIKLÓS , PAPP SÁNDOR , TURBÓK ESZTER , NAGY JULIA 
Published: June 2012

Blood flow to the brain was studied in 11 patients suffering from subclavian steal syndrome. The venous isotope-dilution method was used to measure total blood flow to the brain and the dye-dilution method with intravenous administration of 50 mg of Evans blue was used to determine cardiac output. Cerebral blood flow was significantly lower in the 11 patients with subclavian steal syndrome than in the control group, and the O
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consumption of the brain was low, cerebral resistance was elevated, and the cerebral fraction of the cardiac output was decreased in comparison with the controls.

The effect of occlusion of the ipsilateral brachial artery was studied in 10 of the patients with subclavian steal syndrome. The cerebral blood flow and the cerebral fraction of the cardiac output increased significantly as a result of the occlusion in these patients.
Studies on three patients after surgical correction of the lesion in the subclavian artery showed significant improvement in the cerebral circulation.
Atrial Pacing and Exercise in the Evaluation of Patients with Angina Pectoris
Authors: BAHLER R. C. , MACLEOD C. A. 
Published: June 2012

The anginal threshold was determined by atrial pacing in 23 patients with coronary artery disease. Twelve of the 23 subjects also performed supine exercise at progressive workloads until the onset of angina. Atrial pacing produced a fall in left ventricular stroke work index and left ventricular end-diastolic pressure (LVEDP); cardiac output increased, and, with the onset of angina, left ventricular dysfunction was sometimes evidenced, either by an increase in LVEDP or by an abnormal LVEDP in the postpacing period. In contrast, exercise consistently produced left ventricular dysfunction. The tension-time index at the onset of angina was similar whether the pain was induced by pacing or exercise.
The atrial rate that induced angina bore little relationship to either the clinical or anatomic severity (outlined by coronary arteriography) of coronary artery disease. The exercise workload that produced angina correlated inversely with the quantitated coronary disease. Although atrial pacing is a convenient tool for the study of ischemic ventricular dysfunction, exercise testing provides a more reliable index of functional and anatomic severity of coronary artery disease.
Physiologic Correction of Transposition of the Great Arteries
Authors: WALDHAUSEN JOHN A. , PIERCE WILLIAM S. , PARK C. DICK , RASHKIND WILLIAM J. , FRIEDMAN SIDNEY 
Published: June 2012

The total management of a group of 32 patients with transposition of the great arteries (TGA) is reported. All but one had required creation of an atrial septal defect in infancy. Eighteen patients had no associated cardiac defects, and physiologic correction was performed between 8 months and 9½ years of age. The only death in this group occurred 9 months after operation. Eight of nine patients with TGA and an associated ventricular septal defect (VSD) had required pulmonary artery banding in infancy. Physiologic correction was performed between 2¼ and 6 years of age. Three of these patients died during the postoperative period, and one died 9 months after operation. Two patients had TGA and pulmonary stenosis (PS). Physiologic correction was performed at 2 1/3 and 3¾ years of age. Both patients have done well. Three patients had TGA, VSD, and PS. Total correction was performed between 2 1/3 and 3½ years of age. All three patients died in the postoperative period. The over-all operative mortality was 19%.
Our present plan of management has evolved from the experience reported above. All infants with TGA have balloon atrioseptostomy. If no VSD is present, physiologic correction is performed between 1 and 2 years of age. Patients with TGA and a VSD are catheterized at 8 months of age, and pulmonary banding is performed if pulmonary artery hypertension is present. Physiologic correction is performed at about 4 years of age. Patients with TGA, VSD, and PS may require systemicpulmonary artery anastomosis. Correction at 5 years of age with the use of a homograft from the right ventricle to the pulmonary artery, as described by Rastelli and his associates, is recommended because of the poor results obtained with an intra-atrial baffle in this group.
Diagnostic and Therapeutic Uses of Atrial Pacing
Authors: DESANCTIS ROMAN W. 
Published: June 2012

There are occasions when atrial pacing can be usefully employed both diagnostically and therapeutically. Diagnostically, atrial pacing provides mechanisms for easily, safely, and reproducibly stressing the heart that can help in the evaluation of patients with a variety of cardiac disorders. It is particularly useful in the assessment of patients with coronary disease.
Therapeutically, atrial pacing has been applied in four general areas: (1) to terminate or slow supraventricular tachyarrhythmias; (2) to accelerate the heart rate in patients with sinus bradycardia and intact atrioventricular conduction; (3) to suppress ventricular irritability; and (4) to augment cardiac output. Techniques of atrial pacing are discussed. Currently, a major problem with both temporary and long-term pervenous atrial pacing is erratic pacing. The development of electrodes and pacemakers designed specifically for atrial pacing, as well as further experience with stimulation from the coronary sinus may lead to more reliable pacing.
Efficacy of Isoproterenol-Glucagon Infusion in Patients with Heart Disease
Authors: POLUMBO RALPH A. , LEIGHTON RICHARD F. , WEISSLER ARNOLD M. 
Published: June 2012

Isoproterenol and glucagon were administered separately and in combination by constant rate of intravenous infusion to 13 patients with organic heart disease. Glucagon produced modest increases in cardiac output, heart rate, and arterial pulse pressure. Isoproterenol produced increases in cardiac output and heart rate greater than that achieved with glucagon alone and also increased arterial pulse pressure, stroke volume, and mean rate of left ventricular ejection and decreased systemic vascular resistance.
The same doses of isoproterenol and glucagon in combination produced a greater effect on cardiac output than that achieved with either drug alone and had a greater effect on heart rate and arterial pulse pressure than did glucagon alone. There was no increase in the side effects of either drug associated with their administration in combination.
The present study suggests that the clinical usefulness of glucagon may be enhanced by administering glucagon in combination with isoproterenol in order to obtain the additive hemodynamic benefit of these drugs while minimizing their undesirable side effects.
Effect of Volume Expansion on the Anginal Threshold
Authors: KHAJA FAREEDUDDIN , SANGHVI VIJAY , MARK ALEXANDER , PARKER JOHN O. 
Published: June 2012

The clinical and hemodynamic effects of rapid atrial pacing were studied in 13 patients with coronary artery disease and four normal subjects before and following acute expansion of blood volume with low molecular weight dextran. Five patients developed angina during the initial pacing period. In two of these five patients angina recurred with infusion alone, and all five of them experienced pain during the second pacing period. The anginal threshold averaged 5 min (range, 1 to 8 min) before infusion and 1.8 min (range, 0 to 5 min) following infusion. Four patients with coronary artery disease remained free of pain during the first pacing period, one of these developed pain with infusion alone, and all developed pain during pacing following infusion, the anginal threshold being 2 min (range, 0 to 3 min). The remaining four patients with coronary artery disease did not develop angina during either pacing period.
Administration of dextran was accompanied by an increase in left ventricular end-diastolic pressure in all patients during sinus rhythm and during atrial pacing. Although left ventricular volume was not determined, changes in left ventricular end-diastolic pressure were interpreted as showing directional changes in left ventricular volume. Analysis of the factors affecting myocardial oxygen requirements during the two pacing periods indicated that heart rate, systemic arterial pressure, and maximal rate of rise of left ventricular pressure were similar. Although the tension-time index rose 10.6%, the major change was the increase in left ventricular end-diastolic pressure and presumably in left ventricular volume. This increase in left ventricular volume is considered responsible for the increase in myocardial oxygen requirements following infusion of dextran as determined by the decrease in the anginal threshold in each patient of the angina group.
Hemodynamics of Uremic Anemia
Authors: NEFF MARTIN S. , KIM KWAN E. , PERSOFF MICHAEL , ONESTI GADDO , SWARTZ CHARLES 
Published: June 2012

This study was undertaken to assess the importance of an elevated cardiac output in the generation of the hypertension associated with chronic renal failure. Forty stable uremic patients on a program of maintenance hemodialysis underwent hemodynamic studies. Cardiac index measured by dye dilution was found to be significantly elevated. Calculated peripheral vascular resistance was normal despite elevated blood pressure. Six patients underwent serial hemodynamic studies over a period of 6 to 12 weeks while being transfused with packed red blood cells to a normal hematocrit. Blood volume and body weight were constant during the study period. Cardiac index decreased during transfusion, reaching a normal level at a hematocrit of 30%. Diastolic blood pressure progressively rose, averaging an increase of 20 mm Hg at a hematocrit of 40%. Peripheral vascular resistance increased by 80% at a hematocrit of 40%.
We concluded that the elevation of cardiac index in uremic patients is secondary to anemia and is reversible when the hematocrit is raised over 30%. The high cardiac index is not responsible for hypertension because restoration of cardiac index to normal by transfusion raises blood pressure rather than lowers it.
Combined Papillary Muscle and Left Ventricular Wall Dysfunction as a Cause of Mitral Regurgitation
Authors: MITTAL ARUN K. , LANGSTON MANLY , COHN KEITH E. , SELZER ARTHUR , KERTH WILLIAM J. 
Published: June 2012

Papillary muscle infarction was produced in 16 mongrel dogs by placing sutures around the base of one of the papillary muscles. In addition, patchy infarction of the adjacent left ventricular wall was produced by placing an Ameroid constrictor around the appropriate coronary artery. Mitral insufficiency developed in 14 of these animals; it was severe in four and mild to moderate in ten. Mitral insufficiency was not produced by isolated infarction of a papillary muscle or by isolated infarction of the left ventricular wall.
It is concluded that papillary muscle infarction alone does not lead to mitral regurgitation, but that papillary; muscle dysfunction acts in concert with left ventricular wall dyskinesia or dilatation to produce mitral valve incompetency.
S-T-Segment Depression with Near-Maximal Exercise in Detection of Preclinical Coronary Heart Disease
Authors: KATTUS ALBERT A. , JORGENSEN CHARLES R. , WORDEN RALPH E. , ALVARO ANTHONY B. 
Published: June 2012

Three hundred and fourteen male insurance underwriters had near-maximal treadmill exercise tests after having been evaluated for coronary risk factors. Thirty subjects developed ischemic-type S-T-segment depression during or after exercise not associated with anginal pain. The abnormal electrocardiographic response correlated significantly with elevated serum cholesterol, abnormal rest electrocardiogram, and history of cardiac symptoms; but not with smoking, high blood pressure, physical inactivity, or family history of coronary disease.
In 2.5 years' follow-up there have been among the 30 ischemic responders to exercise testing three coronary deaths, four myocardial infarctions, two who developed angina pectoris, and one who had a coronary angiogram showing multiple obstructions. None of the normal responders to exercise testing has had a coronary event.
Mechanism of Increased Sodium Reabsorption during Propranolol Administration
Authors: NIES ALAN S. , MCNEIL JAMES S. , SCHRIER ROBERT W. 
Published: June 2012

The mechanism of diminished sodium excretion induced by propranolol was investigated in the dog. Propranolol (0.3 to 5 mg/kg) was given intravenously in a bolus to 16 dogs, eight of which had the renal perfusion pressure controlled by a suprarenal aortic clamp. In another group of six dogs propranolol (0.1 to 5 , µg/kg/min) was infused into one renal artery for 45 min. Cardiac output (dye dilution), mean arterial and right atrial pressures, heart rate, renal clearances of inulin, creatinine, and para-aminohippurate, and sodium excretion were measured. Total peripheral resistance, central blood volume, stroke volume, renal plasma flow, renal blood flow, renal vascular resistance, glomerular filtration rate, and filtration fraction were calculated.
Intravenous propranolol resulted in significant decreases in cardiac output (–25%) and heart rate (–14%) and increases in total peripheral resistance (28%) and renal vascular resistance (37%). Renal blood flow decreased by 25% and filtration fraction increased 21% as urinary sodium excretion diminished 36%. Glomerular filtration did not change significantly. Infusions of propranolol into one renal artery resulted in either no change in sodium excretion or bilateral changes; thus an intrarenal effect of the drug was not demonstrable.
The data suggest that the changes in renal hemodynamics associated with propranolol administration are secondary to alterations in systemic hemodynamics, particularly a decrease in cardiac output. These alterations in renal hemodynamics, including an increase in renal vascular resistance and filtration fraction, most likely account for the decrease in sodium excretion rather than a direct effect of propranolol on sodium reabsorption.
Mortality Study of the Significance of Extrasystoles in an Insured Population
Authors: RODSTEIN MANUEL , WOLLOCH LEON , GUBNER RICHARD S. 
Published: June 2012

The prognostic significance of extrasystoles was evaluated in 712 insured persons with this finding who were followed for an average period of 18 years. At the end of the study 356 persons were alive and 125 were dead. Two hundred and thirty-one persons had terminated their policies at a prior date by maturity or discontinuance and were not followed further. Although the lack of follow-up to 1968 of this latter group imposes limitations on the results and conclusions of the study, their exclusion resulted in no significant change in the mortality ratio of the remaining group of 481 persons followed to death or the anniversary of their policies in 1968.
The observed mortality ratios showed no appreciable increase in a group of 604 individuals who were considered to have a normal life expectancy except for the presence of extrasystoles at the time of evaluation for insurance. Similar normal mortality ratios were observed in subgroups with simple and complex supraventricular and ventricular extrasystoles. There was no appreciable difference in mortality when those under 40 and those 40 years of age and over at the time of discovery of extrasystoles were compared. There was no significant difference in mortality between those who responded to exercise with an increase in the number of extrasystoles and those who had no change or a decrease immediately after exercise. An increase in the number of extrasystoles per minute was associated with an increase in mortality. There was a low incidence of sudden death among those with supraventricular extrasystoles.
Ventricular extrasystoles, particularly those of complex types, were associated with a high incidence of death from myocardial infarction, often of a sudden nature, particularly in persons under the age of 56 years. There were too few cases of the individual types of complex ventricular extrasystoles to determine whether this was a characteristic of the group as a whole or of one or more of its constituent types. Ventricular extrasystoles in the presence of other cardiac abnormalities and/or elevation of the blood pressure were associated with an increase in mortality. The mortality experience in such persons was distinctly higher than in those with similar degrees of substandard expected mortality whose abnormalities were not of a cardiovascular nature.
Cardiac Arrest in the Critically Ill
Authors: CAMARATA SAMUEL J. , WEIL MAX HARRY , HANASHIRO PAUL K. , SHUBIN HERBERT 
Published: June 2012

The events preceding cardiac arrest were investigated in 132 critically ill patients on the basis of the hemodynamic, respiratory, and metabolic status prior to cardiac arrest. Approximately one-half of the patients had respiratory acidosis prior to cardiac arrest and only one of these patients ultimately survived. An additional one-fourth had metabolic acidosis due to progressive perfusion failure (shock), and none survived. In the remaining one-fourth, an immediate catastrophic and potentially preventable event accounted for cardiac arrest, and all but one of the long-term survivors were included in this group. In thirteen patients, obstruction or dislodgment of endotracheal tracheostomy tubes, or interruption of ventilation, was recognized as the immediate cause. In an additional 20 patients, cardiac arrest was associated with an adverse effect of a drug. Twelve instances of cardiac arrest were associated with central venous injection of aminophylline.
The initial cardiac resuscitation attempt was effective in 38% of patients. However, the majority of patients who survived the first episode succumbed after a second or third episode. The cumulative survival was disappointingly small. Only six patients, or 5% of the total group of 132 patients, were long-term survivors. These data may provide the basis for more restricted use of routine and repetitive resuscitative measures particularly for elderly patients in whom acidemia is due to progressive ventilatory or circulatory failure.
Sites of Congenital and Surgical Heart Block as Defined by His Bundle Electrocardiography
Authors: ROSEN KENNETH M. , MEHTA ASHWIN , RAHIMTOOLA SHAHBUDIN H. , MILLER ROBERT A. 
Published: June 2012

Catheter recordings of His bundle electrograms were obtained in seven patients with congenital heart block (CHB) and in two with surgical heart block (SHB). In the latter two patients block occurred following total correction of tetralogy of Fallot. In six patients with CHB block occurred proximal to H. In one CHB patient block occurred in the His bundle with "split" H potentials. Intraventricular conduction was normal in five of the patients with CHB who had narrow QRS and H-V intervals ranging from 35 to 45 msec. H-V intervals were short in two CHB patients (25 and 30 msec), one of whom had QRS widening with initial slowing. In the latter patient a functioning infranodal bypass (Mahaim tract) inserting into the right ventricular septum could explain the findings. In the two patients with SHB block was distal to H with P-H intervals of 125 msec and 160 msec, respectively.
The degree of bradycardia and the occurrence of symptoms partially correlated with a location of block in or distal to the His bundle. It is suggested that recording of H potentials is useful in the evaluation of children with complete atrioventricular block.
Evaluation of Pulmonary Arterial End-Diastolic Pressure as an Estimate of Left Ventricular End-Diastolic Pressure in Patients with Normal and Abnormal Left Ventricular Performance
Authors: BOUCHARD RICHARD J. , GAULT JAMES H. , ROSS JOHN 
Published: June 2012

It has been suggested that the pulmonary arterial end-diastolic pressure (EDP) may accurately reflect the level of left ventricular EDP, and therefore be useful in the continuous monitoring of left ventricular EDP in acutely ill patients. Accordingly, pulmonary arterial pressure was recorded simultaneously with left ventricular pressure in 24 patients with normal left ventricular function and in 26 patients with left ventricular myocardial disease and elevated EDP (range 13 to 38 mm Hg; average 22 mm Hg). In patients with normal left ventricular function, the EDPs in the left ventricle and pulmonary artery were equal (range 5 to 12 mm Hg; average 8 mm Hg; maximum difference ± 4 mm Hg). In contrast, in 20 of the patients with impaired left ventricular function, left ventricular EDP was consistently higher than pulmonary arterial EDP, exceeding the pulmonary arterial EDP by 2 to 21 mm Hg (average 8 mm Hg); in 12 of these 20 patients, the pulmonary arterial EDP was 12 mm Hg or less, the upper limit of normal for left ventricular EDP. The left ventricular diastolic pressure prior to atrial contraction correlated more closely with pulmonary arterial EDP. In six patients in whom increases in systemic arterial pressure were induced by methoxamine, and in two patients in whom spontaneous increases in systemic arterial pressure occurred, left ventricular EDP increased by 2 to 11 mm Hg (average 6 mm Hg); pulmonary arterial EDP remained unchanged or increased only slightly (less than 3 mm Hg) in six of the patients, and increased by 4 and 5 mm Hg in the two remaining patients. During increases in heart rate induced by atrial pacing, left ventricular EDP declined in 12 of 14 patients, while pulmonary arterial EDP increased, resulting in a consistent disparity in these pressures (average 11 mm Hg) at heart rates in excess of 124 beats/min.
These data indicate that pulmonary arterial EDP does not provide an accurate estimate of left ventricular EDP in patients with chronic left ventricular disease, and in addition it often fails to reflect acute alterations in left ventricular EDP.