bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hemodynamic Effects of Glucagon in Patients with Heart Disease
Authors: WILLIAMS JOHN F. , CHILDRESS RICHARD H. , CHIP JEROLD N. , BORDER JOHN F. 
Published: June 2012

The intravenous administration of 3 or 5 mg of glucagon to 13 patients with heart disease resulted in a statistically significant increase in heart rate, cardiac index, stroke power index, mean rate of left ventricular ejection, and maximum rate of rise of left ventricular pressure, whereas systemic vascular resistance declined. A moderate increase in mean stroke volume index and stroke work index and a slight fall in left ventricular end-diastolic pressure also occurred, although these changes were not statistically significant. The increase in cardiac index averaged 19%, with nine of the patients demonstrating an increase exceeding 10% of their respective control value. These effects of glucagon generally reached a maximum within 15 min after drug administration and also were of short duration.
Positive inotropic and chronotropic effects of glucagon were observed in most but not all of these patients. In addition, the magnitude of these effects varied considerably among patients; the variation, however, did not appear to be related to the severity or duration of the heart disease.
In eight patients, the infusion of isoproterenol produced greater increases in cardiac index and decreases in left ventricular end-diastolic pressure than glucagon did.
Although the effect of glucagon was short, the frequent improvement in hemodynamics which occurred in the absence of significant side effects, notably arrhythmias, indicates that the inotropic actions of this agent may be useful under certain clinical conditions.
Effects of Atrial Pacing on Left Ventricular Performance in Patients with Heart Disease
Authors: LEIGHTON RICHARD F. , ZARON STEPHEN J. , ROBINSON JOHN L. , WEISSLER ARNOLD M. 
Published: June 2012

Hemodynamic data and systolic time intervals were obtained at resting heart rate and during atrial pacing in 10 patients with heart disease, eight with left ventricular dysfunction, and two with mitral stenosis. The mean increase in heart rate was 44 beats/min. During atrial pacing there was no significant alteration in cardiac output, minute work, left atrial or pulmonary wedge mean pressure, or duration of left ventricular pre-ejection period.
When the pressure events which determine the duration of the isovolumic time and the left ventricular pre-ejection period were examined, aortic diastolic pressure rose while left ventricular end-diastolic pressure fell. The rate of pressure rise (dp/dt) determined from high-fidelity left ventricular pressure pulses in three patients increased out of proportion to the increased pressure developed throughout isovolumic contraction. The augmentation in dp/dt from lower end-diastolic pressure indicates improved mechanical performance of the left ventricle, which is not necessarily translated into hemodynamic improvement.
Etiology and Pathogenesis of Acute Myocardial Infarction
Authors: Killip Thomas , EDWARDS JESSE E. 
Published: June 2012

From the pathological viewpoint, myocardial infarction is but one major consequence of coronary atherosclerosis. Among subjects with chronic occlusive coronary atherosclerosis, more common than death from acute myocardial infarction is death occurring acutely in the absence of infarction or acute coronary occlusion.
Such negative anatomical evidence is supportive of the concept that myocardial ischemia commonly causes serious failure of the circulation through certain ventricular arrhythmias.
Contribution of the Circle of Willis to the Subclavian Steal Syndrome
Authors: LORD REGINALD S. A. , ADAR RAFAEL , STEIN ROBERT L. 
Published: June 2012

The arteriograms and other findings in 42 patients with the subclavian steal syndrome were statistically evaluated to determine which factors predisposed to vertebrobasilar ischemia. Evidence of disconnection of the circle of Willis between the territories of the carotid and vertebral arteries was found in a significantly higher proportion of the patients with vertebrobasilar insufficiency. This finding was interpreted to mean that in these patients one of the major routes normally available for compensating for the basilar ischemia produced by the steal was not present.
It is suggested that this or similar mechanisms may be necessary before the subclavian steal produces symptoms in individual patients.
On-line Analysis of the Exercise Electrocardiogram
Authors: SHEFFIELD L. T. , HOLT J. H. , LESTER F. M. , CONROY D. V. , REEVES T. J. 
Published: June 2012

A computer program has been developed which clarifies the distorted exercise ECG and performs desired measurements of it which are reported in the laboratory almost immediately, so that the program can be used as an aid to exercise test monitoring. We have introduced a new measurement of the ECG, the negative ST (—ST) integral, which while unfamiliar to the eye is readily performed by computer. A —ST integral value of 7.5 µv-sec during exercise served to separate a normal group from a group with angina pectoris. Strenuous exercise was often necessary to elicit positive responses in diseased subjects, and the graded exercise test was found well-suited for this purpose.
Use of a computer program as an investigative instrument in its own right, rather than as a means of duplicating classical human measurements, shows promise for improving the diagnosis of ischemic heart disease.
Effects of a Quantitated Physical Training Program on Middle-Aged Sedentary Men
Authors: SIEGEL WAYNE , BLOMQVIST GUNNAR , MITCHELL JERE H. 
Published: June 2012

The effects of a 15-week quantitated training program were evaluated in nine men, 32 to 59 years old. All had been blind for 10 years or more but were otherwise in good health. They were sedentary with a stable activity pattern. Training sessions were held three times per week and consisted of four 3-minute exercise periods on a bicycle ergometer, each followed by a rest period of equal duration. Heart rates at the end of the fourth exercise period averaged 27 beats below individual maximal heart rates.
Maximal oxygen uptake increased from 24.0 to 28.5 ml/kg x min or by 19%. Total heart volume and mean serum cholesterol decreased significantly, and psychological tests showed improvement.
Five subjects continued exercising at the same intensity but only once weekly for another 14-week period. Mean maximal oxygen uptake decreased to 6% above the control level. Four subjects who discontinued training after 15 weeks were retested at the same time and had a mean value 5% below control maximal oxygen uptake.
Fluttering of the Mitral Valve in Aortic Insufficiency
Authors: WINSBERG FRED , GABOR GEORGE E. , HERNBERG JOSEPH G. , WEISS BARRY 
Published: June 2012

Thirty-five patients with clinical evidence of aortic insufficiency were studied by echocardiography. Eleven patients had characteristic diastolic fluttering of the mitral valve (30 to 40 Hz, maximal amplitude 4 mm). In five others the fluttering was classified as equivocal.
In a control group of 500 echocardiograms in patients without evidence of aortic insufficiency, there were three examples of equivocal fluttering. Atrial fibrillation also produces diastolic fluttering but of slower frequency.
Electrocardiographic Findings Among the Total Adult Population of a Large Religious Isolate
Authors: GOLDBARG ALBERTO N. , KURCZYNSKI THADDEUS W. , HELLERSTEIN HERMAN K. , STEINBERG ARTHUR G. 
Published: June 2012

Electrocardiograms were recorded as part of a survey of 1,303 men and 1,348 women past 15 years of age belonging to a large religious isolate inhabiting regions of northwestern U.S.A. and southwestern Canada. The ECGs were classified according to the Minnesota Code and the abnormalities were related to constitutional characteristics, blood pressure, and serum cholesterol.

Major codable ECG items included abnormal Q waves (54 cases), abnormal left axis deviation (44 cases), bundle-branch block (left 10, right 10), T-wave abnormalities (257 cases), prolonged P-R interval (80 cases), and occasional premature beats (143 cases) and showed no significant sex differences. ST-segment depressions were more common among females (
P
< 0.005). The males showed a significantly higher frequency of increased R-wave amplitude (
P
< 0.005) and more qualitative T-wave changes (
P
< 0.005).

In general, abnormal ECG features were associated with age, sex, and blood pressure, but not with serum cholesterol, body weight and height, skin-fold thickness, or arm girth. A notable exception was the negative relationship of body weight to high amplitude R waves in young males.
In clinical practice, age and sex stratifications will improve the diagnostic power of the ECG.
Embolectomy for Chronic Pulmonary Embolism and Hypertension
Authors: MOOR GORDON F. , SABISTON DAVID C. 
Published: June 2012

The case of a 31-year-old Negro who had had two admissions to the hospital at which pulmonary emboli were diagnosed is reported. On his third admission with chest pain, hemoptysis, and dyspnea, chest roentgenograms revealed increased pulmonary vascular markings on the right and a prominent pulmonary artery which was sharply cut off. ECG changes were typical of pulmonary artery obstruction and pulmonary scan revealed a small perfusion defect in the lower lobe of the right lung and complete absence of perfusion in the left lung. The left pulmonary artery was occluded. An organized thrombus was removed from the left pulmonary artery and from most of its distal branches. Good back flow ensued, and 10 months after operation the patient was well except for some edema of the leg.
A discussion of the problems and indications for pulmonary embolectomy is offered.
Interpretation of Isopotential Surface Maps in Patients with Ostium Primum and Secundum Atrial Defects
Authors: KARSH RICHARD B. , SPACH MADISON S. , BARR ROGER C. 
Published: June 2012

The purpose of this study was to determine if there were consistent differentiating patterns in body surface potential maps in children with normal hearts and in those with ostium primum versus ostium secundum atrial septal defects. A second purpose was to interpret the isopotential surface maps in terms of the position of intracardiac electrical wave fronts.
Body surface activity throughout QRS demonstrated three major intervals: developing, transitional, and declining potentials. Patients with both types of atrial septal defects demonstrated complex distributions (multiple maxima) during the transitional interval which were not encountered in normal subjects. In the primum group, the distribution of positive and negative potentials sequentially changed in an inverted pattern as compared to the pattern in those patients with secundum defects. Furthermore, during the transitional interval the potential distribution was considerably more complex in the primum group. In two additional patients, body surface maps were helpful in clarifying misleading and atypical conventional electrocardiograms.
The presence of simultaneous multiple maxima could only be accounted for by the existence of multiple wave fronts simultaneously present within the heart. In particular the emergence of two widely separated anterior chest maxima in patients with secundum atrial defect indicated the simultaneous presence of prominent left and right ventricular wave fronts. Also, the marked differences in the relative positions of the major body surface maximum and minimum could be accounted for only by considerable differences in the position and extent of intracardiac wave fronts. For example, the target distribution, consisting of an isolated minimum surrounded by multiple maxima and positive potentials over the upper body, in the ostium primum patients, indicated epicardial breakthrough in a wave front positioned in the anterosuperior portion of the heart. In contrast, normal subjects and patients with secundum defect had distributions indicating antero-inferior wave front position at the time of right ventricular epicardial breakthrough.
Acute Effects of Ethanol Ingestion on the Response to Submaximal and Maximal Exercise in Man
Authors: BLOMQVIST GUNNAR , SALTIN BENGT , MITCHELL JERE H. , Vastagh George F. 
Published: June 2012

The acute effects of ingestion of ethanol on the response to submaximal and maximal exercise were studied by noninvasive technics in a group of eight healthy men, ages 21 to 33 (series I). Cardiac output (dye-dilution technic) and intra-arterial pressures were measured in a separate series of experiments in a subgroup of four subjects (series II). Mean concentration of ethanol in the blood at the end of the experiment was 156 mg/100 ml in series I and 125 mg/100 ml in series II. Heart rates at rest and during submaximal exercise were higher after ingestion of ethanol, but there was no effect on stroke volume. After ingestion of ethanol cardiac output at rest and during submaximal exercise increased, and total A-V difference and total peripheral resistance decreased. The circulatory response to maximal work was not affected by ethanol. Maximal oxygen uptake did not change. Pulmonary ventilation was not altered during submaximal exercise but was reduced during maximal work.
These findings are in agreement with data from animal experiments suggesting that ethanol in blood concentrations below 200 mg/100 ml has no significant depressive effect on performance of the normal heart.
Epinephrine Infusion in Man
Authors: SALZMAN STEPHEN H. , WOLFSON STEVEN , JACKSON BRUCE , SCHECHTER ELIOT 
Published: June 2012

A standard test was designed for measurement of the effect of epinephrine infusion on systolic time intervals in 14 normal subjects as a dose-response phenomenon. In order that we might examine the sensitivity of the test, it was applied in nine patients with idiopathic hypertrophic subaortic stenosis.
Normal subjects had a characteristic response—a progressive shortening of the duration of electromechanical systole, left ventricular ejection time, and pre-ejection period. Their left ventricular ejection time, corrected for heart rate, did not change. Patients with idiopathic hypertrophic subaortic stenosis responded to epinephrine infusion with paradoxical lengthening of their left ventricular ejection time, corrected for heart rate. After beta blockade (with propranolol), reinfusion of epinephrine shortened the left ventricular ejection time, corrected for heart rate, to normal levels.
Quantitative Hemodynamic Effects of Heart Rate in Aortic Regurgitation
Authors: JUDGE TERRANCE P. , KENNEDY J. W. , BENNETT LOWELL J. , WILLS ROBERT E. , MURRAY JOHN A. , BLACKMON JOHN R. 
Published: June 2012

The hemodynamic effect of varying heart rate was studied in eight patients with aortic regurgitation. At the subjects' resting sinus rhythm and at a higher heart rate induced with right atrial pacing, left ventricular and aortic pressures and Fick cardiac outputs (FCO) were measured, and left ventricular biplane angiocardiograms were performed. Left ventricular volumes and left ventricular minute flow (LVMF) were determined from the angiograms. Regurgitant flow was quantitated by subtracting the FCO from LVMF. Increased heart rate produced highly significant reductions in the left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume, and stroke volume. End-diastolic circumferential stress (EDCS) and end-diastolic load (EDL) were abnormally high at resting sinus rhythm and were markedly decreased with increased heart rate. FCO increased, but no significant changes were observed in either the LVMF or the regurgitant flow per minute.
Bradycardia in aortic regurgitation may cause pulmonary congestion secondary to high LVEDP and may accelerate left ventricular dilatation secondary to markedly elevated EDCS and EDL. The possible benefits of preventing bradycardia in aortic regurgitation by chronic demand pacing is currently being tested.
Auscultatory Recognition of Aneurysm of the Membranous Ventricular Septum Associated with Small Ventricular Septal Defect
Authors: PIERONI DANIEL R. , BELL BARBARA B. , KROVETZ L. JEROME , VARGHESE P. JACOB , ROWE RICHARD D. 
Published: June 2012

The clinical diagnosis of aneurysmal formation of the membranous ventricular septum associated with a small ventricular defect has been made previously only by means of angiocardiography.
Active movement of the aneurysm during cineangiocardiography suggested the possibility of a corresponding auscultatory event. When careful auscultatory and phonocardiographic examinations were performed on 21 patients previously documented as having a small membranous ventricular defect with an associated aneurysm, a distinct early systolic sound was heard in 17 (81%). This sound was "clicky" in quality, confined to a narrow area along the lower left sternal edge, and best heard in expiration. It occurred during the upstroke of the carotid arterial tracing and followed the Q wave by 100 to 130 msec.
On the basis of experience with other patients the development of this early systolic sound in a patient with a small ventricular septal defect suggests the diagnosis of associated septal aneurysm, but such a sequence requires confirmation by serial angiocardiography. Aneurysmal formation may be a prelude to spontaneous closure of the septal defect in which case auscultation of an early systolic sound should not only prove to be a valuable diagnostic sign for the clinician but may also be of considerable prognostic significance for the patient.
Prevalence of Plasma Lipoprotein Abnormalities in a Free-Living Population of the Central Valley, California
Authors: WOOD PETER D. S. , STERN MICHAEL P. , SILVERS ABRAHAM , REAVEN GERALD M. , VON DER GROEBEN JOBST 
Published: June 2012

In an epidemiologic study of 1,118 free-living volunteers, aged 25 to 79 (552 male, 566 female) drawn from eight counties of the Central Valley, California, the following determinations were included: a medical history, blood pressure, resting electrocardiogram, plasma total cholesterol and glycerides (following a light, fat-free breakfast), and (when lipids were considered to be elevated) plasma lipoproteins determined by electrophoresis. A subgroup of the entire study population (494 male, 503 female) free of overt diabetes and electrocardiographic abnormalities, and with diastolic blood pressure not above 100 mm Hg, that was considered to be clinically "normal," forms the basis of this report.
Significant sex differences for mean levels of total cholesterol were absent or of small magnitude at all age decades up to and including the seventh. In contrast, glyceride levels for men were significantly higher than for women aged 25-59, and differences were substantial. Beyond the seventh decade, females had higher mean levels of both plasma total cholesterol and glycerides.
The type IV lipoprotein pattern was the most common abnormality (8.6%) within the entire normal population and was 2.7 times as common in men (13%) as in women (4.8%). Type II pattern was less common overall (3.7%) and was more frequent in women than in men. Types III (0.2 to 0.4%) and V (0.2%) were both very uncommon, and type I was not encountered. Results were similar when the entire population (normal and abnormal) was considered.
These findings suggest that sex differences in plasma total-cholesterol level cannot account for the known male preponderance in coronary heart disease within the population studied. Prolonged elevation of plasma glycerides (usually expressed as the type IV pattern) in males during the years when atherogenesis is occurring might account for the sex difference.
Further Observations on the Ventricular Echo Phenomenon Elicited in the Human Heart
Authors: SCHUILENBURG REINIER M. , DURRER DIRK 
Published: June 2012

In order to answer the question whether the atrium is a link in the pathway of ventricular reciprocation or whether the A-V node itself is the reflection point of the echo, a special stimulation program was followed in six patients in whom ventricular echo beats with stable time relations could be elicited by regular pacing of the right ventricle or by the application of appropriately timed right ventricular premature beats during regular pacing of the right ventricle. In these experiments the atrial septum was stimulated earlier than the expected arrival at the atrium of the retrograde impulse in the course of the echo sequence. The influence of stepwise (steps of 5 msec) advancing of this atrial "preexcitation" on the timing of the ventricular echo beat was studied.
We found that the atrial septum could be preexcited without interfering with the ventricular echo beat time relations over a time interval less than 5 msec in one patient, less than 10 msec in one, less than 20 msec in two, and less than 30 msec in two cases. When the time interval needed for the stimulated atrial impulse to reach the atrionodal margin is taken into account, it seems likely that the atrium participated in the echo pathway in the four cases with minimal atrial preexcitation intervals of 20 msec or less, and that in the two cases with a minimal atrial preexcitation interval of 30 msec the echo reflection point was localized in the upper part of the A-V node.
Probability of Middle-Aged Men Developing Coronary Heart Disease in Five Years
Authors: KEYS ANCEL , ARAVANIS CHRIST , BLACKBURN HENRY , VAN BUCHEM F. S. P. , BUZINA RATKO , DJORDJEVIC B. S. , FIDANZA FLAMINIO , KARVONEN MARTTI J. , MENOTTI ALESSANDRO , PUDDU VITTORIO , TAYLOR HENRY L. 
Published: June 2012

Characteristics of 11,132 men aged 40-59 years and free from coronary heart disease (CHD) at entry were related to follow-up experience, using multivariate analysis. In 5 years among 2,404 U. S. railroad men and 8,728 European men there were 615 cases of CHD, 214 of whom died from CHD or suffered definite nonfatal infarction.
With five entry characteristics (age, systolic blood pressure, serum cholesterol, smoking habit, and body mass index), multiple logistic solutions for Europeans and Americans, separately, gave estimates of the individual probability of CHD. Classified by deciled scores for these probabilities, the expected and observed CHD cases were highly correlated (r = 0.930-0.981). Predictions based on European data applied to Americans, and vice versa, gave similar high correlations but American incidence was excessive compared with European experience.

Application of the analysis coefficients obtained from data in Europe and in the U. S. railroad to 6,221 other U. S. men 40-59 years of age, CHD-free at entry, gave good prediction of
relative
risk (r = 0.94) for observed versus predicted cases in deciles of risk score; however, the actual numbers of cases were underpredicted.

From single measurements of a few characteristics the multiple logistic solution usefully estimates the relative risk of CHD for individuals. Age, systolic pressure, and serum cholesterol are universally powerful predictors of risk. Variables not measured in this study or not yet identified contribute to the risk of CHD among American men.
Some Reflections on the Coronary Bypass Operation
Authors: GLENN WILLIAM W. L. 
Published: June 2012

A promising new operation-coronary bypass-has been developed for the treatment of coronary heart disease. However, because of the nature of the underlying disease and the minute size of the vessels to be anastomosed, its long-range prospects are in doubt. At this point in time there is no evidence that the operation either prevents infarction or prolongs life, and great caution is urged in applying it, reserving it for those who have life-threatening coronary artery disease, are clearly recalcitrant to optimum medical management, and have apparently normal coronary vessels distal to the point of stenosis.
There is an urgent need for a better definition of the indications for operation in patients with coronary artery disease based on a study of the natural history of this coindition. Prophylactic operation for patients with a compromised coronary circulation with or without angina must await long-term results of therapeutic operation.