bluuebunny/crossref_metadata_2025 huggingface dataset:
A cause of paired ventricular extrasystoles.
Authors: Kinoshita S , Fujita K , Kanda K , Tanabe Y , Kawasaki T
Published: June 2012

Eight patients with ventricular extrasystoles are reported in whom coupling intervals of the extrasystoles to the proceding sinus beats were variable and in whom paired ventricular extrasystoles were occasionally seen. In all patients, paired ventricular extrasystoles were initiated only by comparatively late coupled ventricular extrasystoles. However, the interval between the first and the second of these paired extrasystoles was always much shorter than the coupling interval of this first extrasystole to the preceding sinus beat, so that the latter extrasystole often interrupted the T wave of the first one, indicating the R-on-T phenomenon. In two patients there was a gap between the ranges of coupling intervals for single extrasystoles and for the first ones of paired extrasystoles. These observations suggest the presence of longitudinal dissociation in the reentrant pathway as one of the causes of paired ventricular extrasystoles.
In-hospital prognosis of patients with first nontransmural and transmural infarctions.
Authors: Thanavaro S , Krone R J , Kleiger R E , Province M A , Miller J P , deMello V R , Oliver G C
Published: June 2012

We studied the in-hospital mortality and morbidity of 745 patients who had suffered a first myocardial infarction. One hundred twenty-four patients (16.6%) had nontransmural infarction and 621 (83.4%) had transmural infarction. Both groups of patients were similar in the distribution of age, sex, and coronary risk factors. Patients with nontransmural infarction had a significantly lower mortality (3% vs 11%, p less than 0.01) and a lower prevalence of premature ventricular complexes (81% vs 88%, p less than 0.05). The patients with transmural infarction were distributed evenly among the three subgroups with peak SGOT levels less than 120 units, 120-240 units and more than 240 units (31%, 34% and 35%, respectively), while most patients with nontransmural infarction (60%) had peak SGOT levels less than 120 units (p less than 0.0001). When the in-hospital mortality and morbidity were compared between the parallel subgroups, the prognosis of patients with the two types of infarctions was similar. This study shows that the peak SGOT level is more important than the type of infarction in determining the acute mortality and morbidity of first myocardial infarction.
Multiple-lead QRS changes with exercise testing. Diagnostic value and hemodynamic implications.
Authors: Berman J L , Wynne J , Cohn P F
Published: June 2012

To evaluate the diagnostic potential and hemodynamic significance of exercise-induced multiple-lead QRS changes, we studied exercise test responses in 230 patients with chest pain syndromes undergoing Bruce protocol exercise tests. When increases in the R waves of multiple ECG leads (epsilon R) plus ST segment change greater than 1 mm were present, 74 of 75 patients (99%) had coronary disease; this was a higher percentage than that achieved with either measurement alone or when ST change was combined with increase in R in a single lead. Sixty-four of the 75 patients (85%) had multivessel disease, the most severe form of coronary artery disease. Left ventricular end-diastolic pressure (both at rest and after left ventriculography), presence and degree of resting ventricular asynergy, and ejection fraction were all significantly more abnormal in patients whose epsilon R increased, regardless of ST-segment change. Further, in patients who stopped exercise because of cardiac symptoms, exercise duration and the product of heart rate times blood pressure were significantly lower when epsilon R increased. Thus, the mechanism for the increase in epsilon R with exercise in patients with coronary artery disease appears to be related to abnormalities in left ventricular function.
Contribution of dynamic vascular wall thickening to luminal narrowing during coronary arterial constriction.
Authors: MacAlpin R N
Published: June 2012

Available estimates of the ratio of wall thickness to luminal radius of human coronary arteries and certain geometrical assumptions were used to calculate the amounts of vascular smooth muscle shortening required to produce specific changes in luminal diameter for hypothetical "normal" and stenotic arteries. The results indicate that even modest mural thickening due to disease may act as a "lever" in translating physiologic degrees of medial smooth muscle shortening into critical luminal obstructions, providing the diseased segment maintains some pliability. The possibility of acute luminal occlusion occurring at stenotic sites as the result of "normal" vasomotion is illustrated. The appropriate use of the term coronary arterial "spasm" is discussed in light of these observations.
Dickinson W. Richards Lecture: Circulatory adjustments to hypoxia.
Authors: Heistad D D , Abboud F M
Published: June 2012

Circulatory adjustments during hypoxia act to redistribute blood flow and maintain arterial pressure. Redistribution of blood flow is accomplished by a local effect of hypoxia, which produces dilatation in coronary and cerebral vessels, and the chemoreceptor reflex, which produces vasoconstriction in skeletal muscle and the splanchnic bed and dilatation in coronary vessels. Arterial pressure is maintained primarily by the chemoreceptor reflex. If the chemoreceptor reflex fails to maintain arterial pressure, hypoxia and hypotension together activate the central pressor response. Compensatory mechanisms usually are sufficient to maintain homeostasis during hypoxia. However, when a hypotensive stress is superimposed during hypoxia, compensatory mechanisms may fail to maintain arterial pressure. Thus, systemic hypoxia interferes with autonomic cardiovascular adjustments.
Genetic--epidemiologic study of early-onset ischemic heart disease.
Authors: Nora J J , Lortscher R H , Spangler R D , Nora A H , Kimberling W J
Published: June 2012

A genetic-epidemiologic study was undertaken of a white Colorado population of 207 patients who had a myocardial infarction before age 55 years. Nineteen independent variables were compared between the 207 cases and 621 controls, matched 3:1. The highest risk ratios were associated with a positive family history for ischemic heart disease (IHD). The heritability of IHD was 63% when families with the monogenic forms of hyperlipoproteinemia were included, and 56% when they were excluded. A risk index was developed that incorporates family history into a data base of risk factors, which can be readily assessed by the clinician obtaining a screening history, physical and standard laboratory tests. A scale of 0-10 was devised and the predictive value of the index was tested against another data set. The efficiency of the index was maximal at a screening level of 5. This study suggests that it is logistically feasible to seek patients at high risk for intensive management in a clinical setting (high-risk strategy) using risk indices similar to the one developed for this study, which emphasize the very important familial component to IHD.
Clinical significance of upsloping ST segments in exercise electrocardiography.
Authors: Rijneke R D , Ascoop C A , Talmon J L
Published: June 2012

Conventional exercise electrocardiographic criteria usually involve patterns with a horizontal or downsloping ST segment. In the present study we present criteria based on upsloping ST segments and compared these criteria with the conventional criteria. Using upsloping ST-segment criteria, the amount of ST-segment depression at 80 msec after the end of the QRS complex is used as a parameter (ST criterion E, with a depression of 100 mV, and ST criterion F, with a depression of 200 mV). In the graded exercise test a bicycle ergometer was used. The ECG leads were CM5 and CC5. The results of exercise electrocardiography were compared with the findings from coronary arteriography. In 623 selected patients (565 males and 58 females), application of conventional ST criteria gave a sensitivity of 56% and a specificity of 94%; with application of the ST criteria E or F, sensitivity was 75% and specificity 90%. In the 58 females use of these new criteria resulted in a sensitivity of 76% and specificity of 88%. Ninety-three patients (15%) could be classified as positive exercise responders by the sole presence of an upsloping ST segment (type E or F). Sixty-eight percent of the patients with type E and 75% with type F had two- or three-vessel disease (coronary obstructions greater their or equal to 50%). We conclude that ST criteria based on upsloping ST segments significantly increase the diagnostic yield of the exercise ECG.
Echocardiographic evaluation of long-term effects of exercise on left ventricular hypertrophy and function in professional bicyclists.
Authors: Nishimura T , Yamada Y , Kawai C
Published: June 2012

Echocardiographic examinations were performed in 60 professional bicyclists and control subjects to determine the effects of exercise on left ventricular hypertrophy and function. The athletes were separated by age into three groups: group 1 (n = 14), 20-29 years; group 2 (n = 17), 30-39 years; and group 3 (n = 29), 40-49 years. Echocardiograms showed enlargment of the left ventricular end-diastolic dimensions in all three groups compared with age-matched control groups (p less than 0.001). Thickness of the interventricular septum and the left ventricular posterior wall was more prominent in group 3 of the athletes than groups 1 and 2 of the athletes and control group (p less than 0.001). Resting left ventricular function evaluated with fractional shortening, ejection fraction and mean velocity of circumferential fiber shortening was significantly depressed in group 3 compared with the other groups. Moreover, 14% of group 3 subjects showed enlargement of left atrial dimension and T-wave inversion in the left precordial leads of the ECG. We conclude that left ventricular hypertrophy is an important ventricular adaptation in relatively young athletes. However, middle-aged athletes may be more susceptible to electrocardiographic abnormalities and prominent hypertrophy, and some may have slightly depressed left ventricular function.
Cross-sectional echocardiography. II. Analysis of mathematic models for quantifying volume of the formalin-fixed left ventricle.
Authors: Wyatt H L , Heng M K , Meerbaum S , Gueret P , Hestenes J , Dula E , Corday E
Published: June 2012

Cross-sectional echocardiography was used to quantify volume in 21 canine left ventricles that were fixed in formalin and immersed in mineral oil. Area, length and diameter measurements were obtained from short- and long-axis cross-sectional images of the left ventricle and volume was calculated by seven mathematic models. Calculated volume was then compared, by linear regression and percent error analyses, with fluid volume of the left ventricle, obtained by filling the chamber with a known amount of fluid. Volumes ranged from 13-146 ml. Mathematic models using short-axis area and long-axis length gave higher correlation coefficients (r = 0.982 and r = 0.969) and lower mean errors (10-20%) than standard formulas previously used for M-mode echo and angiography. Thus, short-axis area analysis with cross-sectional echocardiography is well-suited for quantifying left ventricular volumes in dogs.
Ventricular premature complexes in prognosis of angina.
Authors: Ruberman W , Weinblatt E , Goldberg J D , Frank C W , Shapiro S , Chaudhary B S
Published: June 2012

We studied the prognostic role of ventricular premature complexes occurring during 1 hour of electrocardiographic monitoring of 416 men with effort angina who had never had myocardial infarction, and compared mortality over 5 years with that of 1739 men with infarction before first observation. Multivariate analyses of survival identified the presence of ventricular premature complexes in 1 hour of monitoring, the presence of ST-segment depression on the standard ECG, and age as the variables making the most important independent contributions to risk of death (all causes and sudden coronary deaths) among the men with angina. The relatively lower age-adjusted 5-year mortality among men with angina compared with those who had a prior myocardial infarction reflects the lower prevalence in the former group of indicators of myocardial dysfunction, such as ventricular ectopic activity and ST-segment depression.
Body surface distribution of electrical potential during atrial depolarization and repolarization.
Authors: Mirvis D M
Published: June 2012

Limited information is available documenting body surface isopotential distributions during atrial excitation and recovery. To expand the current data base, body surface isopotential maps from 40 normal subjects were examined. Data were acquired at a gain of 10,000 and isopotential distributions constructed at 2-msec intervals from the onset of the P wave to the onset of the QRS complex. During the initial half of the P wave, a left midprecordial maximum dominated the distribution. Negative potentials existed over the upper back. Subsequently, the maximum migrated to the left; negative potentials moved into precordial areas. Near the end of the P wave, the maximum shifted to the left back as a minimum evolved over the midprecordium. This minimum increased in intensity and remained stationary throughout the PR segment. These patterns are consistent with previously reported epicardial records from canine preparations documenting initial right and then left atrial activation, and repolarization beginning before the end of excitation and enveloping much of the posterior atrial epicardium with low-level positive potential. All distributions had but a single maximum and/or minimum, consistent with a single dipole equivalent cardiac generator.
Apolipoprotein A-I, A-II and C-II in black and white residents of Evans County.
Authors: Tyroler H A , Heiss G , Schonfeld G , Cooper G , Heyden S , Hames C G
Published: June 2012

Plasma levels of lipids, lipoprotein-cholesterol and three major apolipoproteins (ApoA-I, A-II and C-II) were studied in 318 black and white males and females randomly sampled in Evans County, Georgia. Black-white differences in lipid and lipoprotein-cholesterol concentrations were observed, with low-density fractions higher in whites and high-density fractions higher in blacks. Plasma levels of ApoA-I but not ApoA-II were higher in blacks than in whites and in females than in males. ApoC-II concentrations were lower in black than in white men and women. Black-white differences in atherogenic lipoprotein fractions were statistically explained (in the sense of association, not necessarily of causal process) by the differences in ApoC-II concentrations between the race groups. Black-white differences in anti etherogenic high-density lipoprotein-cholesterol were greater than statistically predicted by differences in ApoA lipoprotein levels. The findings are indicative of black-white differences in lipoprotein composition.
The effect of partial ileal bypass on plasma lipoproteins.
Authors: Moore R B , Buchwald H , Varco R L
Published: June 2012

Plasma lipids and lipoprotein cholesterol concentrations were determined before and at 3 months and 1 year after partial ileal surgery in 28 male survivors of first myocardial infarction (eight normolipidemic subjects and eight type II-A, two type II-B, eight type IV and two type V hyperlipoproteinemic subjects). All subjects had marked reductions in plasma total cholesterol (average 45% and 33% in the type V subjects and 37% and 31% in the other 26 subjects at 3 months and 1 year after surgeryyy). Except for the two type V subjects, all had even more marked reductions in low-density lipoprotein (LDL)-cholesterol than in the total plasma cholesterol, averaging 51% at 3 months and 49% at 1 year after surger. There were no significant changes in high-density lipoprotein (HDL)-cholesterol levels. The hypertriglyceridemic subjects had marked reductions in plasma triglycerides and very low density lipoprotein-cholesterol, whereas the normotriglyceridemic subjects (normals and II-A) had slight increases in these two measurements after surgery. Partial ileal bypass tends to normalize elevated plasma lipid and lipoprotein levels and results in a maximal lowering in LDL-cholesterol concentrations without altering the HDL-cholesterol level.
Clinical and pathologic features of obstructive disease in the predominant right and left coronary circulations in man.
Authors: Boucek R J , Romanelli R , Willis W H , Mitchell W A
Published: June 2012

The clinical features and the location and severity of obstructive coronary artery disease are contrasted in 98 patients with predominant left and 99 patients with predominant right coronary circulations. A significantly higher incidence of ventricular conduction disturbances and a greater incidence and severity of obstructive coronary artery disease (greater than or equal to 70% cross-sectional narrowing in the proximal left anterior descending, circumflex and right coronary arteries and their major branches) distinguish the predominant left from the predominant right coronary circulation. The results suggest an anatomically disadvantaged status for the predominant left compared with the predominant right coronary circulations with respect to ventricular conduction disturbances and to coronary atherogenesis in man.
Motion of the interatrial septum in acute mitral regurgitation. Clinical and experimental echocardiographic studies.
Authors: Tei C , Tanaka H , Nakao S , Yoshimura H , Minagoe S , Kashima T , Kanehisa T
Published: June 2012

The interatrial septal echocardiograms from 15 patients with acute mitral regurgitation due to ruptured chordae tendineae were compared with those from 14 normal subjects. On the cross-sectional echocardiogram, the interatrial septal configuration in patients with chordal rupture showed a characteristic pattern in which the interatrial septum (IAS) was flat or slightly convex toward the left atrium at end-diastole and became markedly convex toward the right atrium at end-systole. On the M-mode echocardiogram, the interatrial septal amplitude was greater in patients with chordal rupture (12.4 +/- 1.9 mm) than in normal subjects (9.4 +/- 0.9 mm). Systolic fluttering of the IAS was found in five of 10 patients with rupture of the chordae attached to the posterior mitral leaflet. This finding was thought to be specific for acute mitral regurgitation due to ruptured chordae to the posterior mitral leaflet. After operation, the amplitude of the IAS became normal or diminished and systolic fluttering of the IAS disappeared. Animal experiments performed to clarify the mechanism of these findings showed that increased systolic motion of the IAS resulted from an increased in the systolic left atrial-to-right atrial pressure gradient due to acute mitral regurgitation. The systolic fluttering of the IAS was thought to represent a jet stream against the IAS due to rupture of the chordae tendineae to the lateral half of the posterior mitral leaflet. We conclude that the interatrial septal echocardiogram reflects the hemodynamic changes due to acute mitral regurgitation and direction of the regurgitant jet against the IAS. This finding may prove to be important in diagnosing acute mitral regurgitation secondary to ruptured chordae tendineae.
Predictors of clinical course, coronary anatomy and left ventricular function after recovery from acute myocardial infarction.
Authors: Taylor G J , Humphries J O , Mellits E D , Pitt B , Schulze R A , Griffith L S , Achuff S C
Published: June 2012

Patients who survive an acute myocardiac infarction (AMI) have significant coronary disease and are at risk for angina pectoris, recurrent myocardiac infarction and sudden death. This study provides data gathered prospectively for 106 patients surviving myocardial infarction who had coronary arteriography, left ventriculography and 24-hour electrocadiographic recordings before hospital discharge and were followed 30 months. Univariate analysis showed that low ejection fraction, proximal left anterior descending coronary disease and significant disease in all three coronary arteries were associated with a high risk of sudden cardial death. The ECG location or type of infarction was not helpful in predicting mortality, reinfarction or continuing angina. Multivariate analysis of 30 clinical and laboratory variables identified previous myocardial infarction and an ejection fraction less than 40% as the best predictors of mortality; all 13 patients who died were identified by these two variables. Three-vessel coronary artery disease, proximal left coronary disease and complicated late hospital-phase ventricular arrhythmias did not provide additional information about mortality once the information provided by the first two variables was considered. Multivariate analysis identified hypertension, three-vessel coronary disease, postinfarction angina pectoris and previous AMI as significant predictors of recurrent AMI during the 30 month follow-up.
The physiologic effects of digoxin under steady-state drug conditions in newborn and adult sheep.
Authors: Berman W , Musselman J , Shortencarrier R
Published: June 2012

The physiologic response to the chronic administration of digoxin was studied in 12 adult and 13 newborn sheep. Vascular pressures, cardiac output, isovolumic contraction phase indexes and systolic time intervals were measured before and after 2 weeks of digoxin therapy. Physiologic measurements were correlated with drug levels in plasma and myocardium. Resting myocardial function in newborns exceeded that in ewes. In ewes, the heart rate decreased from 98 to 74 beats/min, the preejection period (PEP) decreased from 76 to 57 msec, the ratio of PEP to left ventricular ejection time (LVET) decreased from 0.323 to 0.223 and dP/dt max increased from 2415 to 3460 mm Hg . sec-1 as plasma concentrations of digoxin increased to a mean of 1.8 ng/ml. Although the final steady-state plasma concentration of digoxin in newborn lambs averaged 1.7 ng/ml, cardiac output, PEP, PEP/LVET and dP/dt max did not change significantly from baseline values. These studies suggest that developmental differences in the physiologic response to digoxin are due either to a limited capacity for improvement in myocardial contractility shortly after birth or to an age-related difference in the effect of digoxin on myocardial tissue.
Lipoproteins in patients with proved coronary artery disease: qualitative and quantitative changes in agarose-gel electrophoretic patterns.
Authors: Bahler R C , Opplt J J , Waggoner D M
Published: June 2012

The relationship between the configuration of agarose-gel lipoprotein electrophoresis patterns and the extent of coronary artery disease (CAD) was studied in consecutive patients undergoing diagnostic coronary angiography. Three groups were identified: patients with normal coronary arteries (group 1), patients with minor luminal irregularities (group 2) and patients with significant coronary artery obstructions (group 3). Densitometric scans of the electrophoretograms were studied to determine the relative proportion of lipoproteins in each major fraction and the configuration of the pre-beta complex. The presence of multiple subfractions within the pre-beta lipoprotein complex had a sensitivity of 66% for the presence of CAD and a specificity of 99%. A decreased level of alpha 1 lipoproteins, defined as less than 25% of total lipoproteins, occurred almost entirely in groups 2 and 3, whereas an increased level (greater than or equal to 28%) of pre-beta lipoproteins was less specific for CAD. The proportions of alpha and pre-beta lipoproteins were inversely related (r = 0.677). Although abnormalities of serum cholesterol and/or triglycerides were common in groups 2 and 3, the detailed study of lipoprotein patterns provided a more sensitive index of disordered lipoprotein metabolism. The angiographic severity of CAD was significantly related to age and to levels of serum triglycerides, alpha 1 lipoproteins, and pre-beta lipoproteins. The lipoprotein electrophoretogram, in conjunction with serum lipid levels, is a valuable tool for demonstrating abnormalities of lipoprotein metabolism associated with CAD.
Parietal Focal Block: An Experimental and Electrocardiographic Study
Authors: ALZAMORA-CASTRO V. , ABUGATTAS RICARDO , RUBIO CARLOS , BOURONCLE JOSÉ , ZAPATA CESAR , SANTA-MARÍA EDUARDO , BATTILANA GUIDO , BINDER TEODORO , SUBIRÍA RICARDO , PAREDES DAVID
Published: June 2012

A method of producing focal ventricular block is described. The sequence of the electrocardiographic variations is ascribed to changes in the velocity and direction of the excitatory process in the ventricular wall. The epicardial electrocardiograms resemble those considered indicative of ventricular hypertrophy or of "incomplete" or of "complete" bundle branch block. When the focal block is pronounced a positive deflection appears in the cavitary tracing. The ventricular blocks can be subdivided into "conduction blocks" and "fiber blocks," the former produced by the delay of the stimulus in the specialized conduction system and the latter produced by the delay of the excitatory process in the ordinary heart muscle.
The Effect of Posture on the Excretion of Water and Sodium by Patients with Congestive Heart Failure
Authors: LOMBARDO THOMAS A.
Published: June 2012

Four patients with congestive heart failure were studied in the sitting and the recumbent positions. After hypotonic loading maximal diuresis set in at six hours, as compared with three hours in the normal subjects. Heart failure patients never excreted more than 50 per cent of water intake in either position. Likewise, these patients never equalled sodium intake with urinary excretion of sodium. Sodium excretion in the two positions was approximately the same. Increase in venous pressure, lengthening of circulation time, decline of vital capacity, and decline of serum sodium concentration were noted after each investigation period. These results are interpreted as indicating that the previously postulated intracranial volume regulating center is either inactive or over-powered by a more powerful mechanism in the patient with congestive heart failure.
The Effects of Hexamethonium on Certain Manifestations of Congestive Heart Failure
Authors: KELLEY ROBERT T. , FREIS EDWARD D. , HIGGINS THOMAS F.
Published: June 2012

Hypotensive doses of hexamethonium were administered intravenously to 19 patients with various types of heart disease in congestive failure. Clinical improvement as judged by the usual methods was seen in most cases. Intracardiac or pulmonary artery pressures paralleled the fall of arterial pressures following hexamethonium in four patients with hypertensive heart disease in congestive failure. It is suggested that hexamethonium, by reducing the total peripheral resistance and by a redistribution of blood volume, may interrupt the vicious cycle of heart failure.
A Study of the Relationship between Unipolar Leads and Spatial Vectorcardiograms, Using the Panoramic Vectorcardiograph
Authors: MILNOR WILLIAM R. , TALBOT SAMUEL A. , NEWMAN ELLIOT V.
Published: June 2012

The extent to which precordial and other unipolar leads are influenced by the proximity of the exploring electrode to one part or another of the heart is the subject of considerable debate. Oneapproach to the problem is to determine how closely precordial leads can be predicted from spatialvectorcardiograms recorded by leads relatively remote from the heart. The panoramic vector-cardiograph described below provides a convenient way of doing this, since it automatically records scalar derivations from the vectorcardiogram for any spatial axis. Results indicate that local effects are not the predominant factor in determining the form of the complexes in precordial leads.
A Study of Unipolar Left Back Leads and Their Application to Posterior Myocardial Infarction
Authors: ELEK STEPHEN R. , HERMAN LAWRENCE M. , GRIFFITH GEORGE C.
Published: June 2012

The electrocardiographic diagnosis of myocardial infarction of the posterior wall is often missed because it is largely dependent on lead and because this electrode position often does not subtend the diseased myocardium. To remedy this defect, a new method is described—unipolar left back leads. The validity of this method in registering potential from the posterior left ventricular wall is discussed as well as its importance in the diagnosis of myocardial infarction of the posterior wall. Left back leads can illuminate the significance of questionable Q waves.
The Measurement of Liver Circulation by Means of the Colloid Disappearance Rate
Authors: DOBSON ERNEST L. , WARNER GEORGE F. , FINNEY CAROLINE R. , JOHNSTON MURIEL E.
Published: June 2012

A method for calculating the liver blood flow by means of the rate of disappearance of colloidal chromic phosphate from the blood has been reviewed. This method has been applied to the study of liver circulation in a group of 29 fasting normal men. The significance of the colloid disappearance rate constant as a physiologic expression of the liver blood flow has been discussed and the average value obtained for this constant in normal young men was 0.287 ± 0.007 min.–1 Extra hepatic colloid localization, hepatic efficiency for colloid removal, speed of mixing, and type and time of sampling have been discussed.
A Proposed Nomenclature and Convention for Recording the Ballistocardiogram
Authors: BRAUNSTEIN JOHN R.
Published: June 2012

When this paper was submitted to the editors of CIRCULATION it called to their attention the desirability of enlarging the work that Dr. Braunstein has begun in the following paper. Accordingly, Dr. Howard Sprague, President of the American Heart Association appointed a committee to study the field and to make recommendations leading toward both a uniform terminology and uniform methods of presenting data secured by ballistocardiographs, and Dr. Braunstein kindly consented to withhold the publication of his paper until the committee was ready to report. This committee has now approved the terminology suggested by Dr. Braunstein and, in a first report, which immediately follows Dr. Braunstein's paper, makes other recommendations pertaining to terminology and conventions for parts of the field not covered by Dr. Braunstein's paper.
The Effect of Priscoline on the Clearance of Radiosodium from Muscle and Skin of Man in Normal and Diseased Limbs
Authors: FREUND JACK , WISHAM LAWRENCE H. , YALOW ROSALYN S.
Published: June 2012

The radiosodium clearance technic was used to measure the effect of Priscoline given intraarterially on the effective blood flow in muscle and skin of normal subjects and patients with peripheral vascular disease. The only clinically significant increase in the clearance rate of radiosodium (Na
24
) occurred in the skin; the clearance rate in muscle showed small increases which were constantly present but not considered to be clinically significant.
Rheumatic "Activity" as Judged by the Presence of Aschoff Bodies in Auricular Appendages of Patients with Mitral Stenosis
Authors: DECKER J. P. , VAN Z. HAWN C. , ROBBINS S. L.
Published: June 2012

Left auricular appendages from 183 patients, removed at operation for mitral stenosis, have been studied with regard to presence of Aschoff bodies and endocardial thrombi. An over-all incidence of Aschoff lesions of 40 per cent was found. There was a significant decrease in Aschoff lesions in the presence of thrombosis. The occurrence of Aschoff bodies in the appendages is correlated with the findings in the remainder of the heart in autopsied cases.
Further Observations on the Effects of Autonomic Blocking Agents in Patients with Hypertension
Authors: GROB DAVID , LANGFORD HERBERT G. , ZIEGLER BARBARA
Published: June 2012

Hexamethonium and pentamethonium produced a greater reduction in blood pressure in patients with malignant hypertension who had low serum concentration of sodium or severe encephalopathy than in those with benign hypertension. Concurrent administration of hydrazinophthalazine resulted in an additive effect on the blood pressure of most patients, with slower development of tolerance and less marked postural hypotension. In many patients there was improvement in signs and symptoms attributable to hypertension. Harmful effects of reduction in blood pressure occurred mainly in patients with malignant hypertension and consisted of renal insufficiency and evidence of myocardial and retinal ischemia.
A Comparison of Direct and Indirect Blood-Pressure Determinations
Authors: ROBERTS L. N. , SMILEY J. R. , MANNING G. W.
Published: June 2012

In this study a comparison between direct and indirect methods of obtaining blood pressure has been made. A statistical analysis of the data supports the view that the muffling of sounds, or the fourth phase of Korotkow, bears a closer and more constant relationship to diastolic pressure measured directly. This report, therefore, recommends the acceptance of muffling of the sounds of Korotkow as the measure of diastolic pressure.
The Spatial Orientation of the Plane Including the Mean QRS and T Vector of the Normal Electrocardiogram
Authors: KIMURA NOBORU
Published: June 2012

For measurement of the spatial orientation of planes in the analysis of the spatial vectorcardiogram, a simple device is developed to be used with Simonson's vector analyzer for the conventional electrocardiogram. The prospective value of this method is shown for the measurement of the plane including the mean QRS and T vector.
Age Changes in Heart Rate and Blood Pressure Responses to Tilting and Standardized Exercise
Authors: NORRIS ARTHUR H. , SHOCK NATHAN W. , YIENGST MARVIN J.
Published: June 2012

Tilting and standardized exercise caused extensive shifts of heart rate and auscultatory blood pressures in 140 ambulatory male subjects from 20 to 92 years of age. Following similar exercise, the older subjects showed a greater increase of heart rate and pulse pressure than did the younger subjects who compensated the changes caused by tilting more completely and rapidly than did the older subjects. These slower compensatory responses of older subjects should be considered in the interpretation of metabolic recovery rates after exercise.
Congenital Aneurysm of the Right Sinus of Valsalva, Diagnosed by Aortography
Authors: FALHOLT WALTHER , THOMSEN GREGERS
Published: June 2012

This paper contains a brief review of the cases, published earlier, of aneurysms of the sinuses of Valsalva, and a case is reported in which the diagnosis was made before rupture of the aneurysm by means of thoracic aortography. No reports are to be found in the literature of the diagnosis of unruptured aortic sinus aneurysms and of the associated clinical findings. Roentgenograms, aortograms and catheterization findings are included.
Norepinephrine in Shock Following Myocardial Infarction
Authors: SAMPSON JOHN J. , ZIPSER ALBERT
Published: June 2012

A clinical study is presented of the influence of continuous intravenous norepinephrine therapy upon shock accompanying myocardial infarction. The significant reduction in immediate and eventual mortality rates usually associated with this condition are discussed. Complications are defined, and a possible first reported instance is presented of ventricular tachycardia developing in the presence of complete heart block during the administration of large doses of norepinephrine.
Mechanical Inscription of the Vectorcardiogram
Authors: WITHAM A. CALHOUN , HAMILTON WM. F.
Published: June 2012

A modification of the vectorcardiographic method of studying electrical events is presented. Simultaneous scalar leads, taken by any vector lead system, are first recorded. The important time intervals, difficult or impossible to read from the loop itself, are measured from these tracings. Proper pairs of the scalar leads can then be rapidly integrated into vector loops by an easily constructed drawing board based on the pulley system. This instrument is described in detail. It is demonstrated that loops so derived do not appear to differ in their important characteristics from electronically integrated loops.
An Evaluation of Certain Vasodilator Drugs by a Heat Flow Technic
Authors: CATCHPOLE B. N. , JEPSON R. P.
Published: June 2012

The effects on the skin heat flow, using a copper-tellurium disc technic, of Tolazoline (Priscoline), Hydergine, Regitine and P-9295 when administered parenterally are compared with the results of reflex heat vasodilatation, in normal and atherosclerotic limbs.
Treatment of Stokes-Adams Disease by External Electric Stimulation of the Heart
Authors: ZOLL PAUL M. , LINENTHAL ARTHUR J. , NORMAN LEONA R. , BELGARD ALAN H.
Published: June 2012

An external cardiac pacemaker was developed and was used to stimulate the heart electrically in a series of patients with recent Stokes-Adams syncope. It resuscitated patients from attacks due to ventricular standstill; it maintained an adequate circulation during persistent ventricular standstill; and it prevented the recurrence of irregular ventricular tachycardia. Several patients have now survived for many months without recurrent syncope. Such long survivals suggest that the periods of cardiac disturbance which cause syncope may subside if the patient is kept alive during the crucial period.
Intravenous Hexamethonium Sensitivity and Responses to Oral Treatment
Authors: GREEN D. M. , ELLIS EUGENE J.
Published: June 2012

This study represents an effort to distinguish between neurogenic and humoral vasoconstrictive factors in a representative group of hypertensive patients by the response to hexamethonium ganglionic blockade. The correlation between intravenous hexamethonium sensitivity and subsequent treatment response was also determined.
Circulatory Changes in Acute Myocardial Infarction
Authors: GILBERT ROBERT P. , GOLDBERG MELVIN , GRIFFIN JOSEPH
Published: June 2012

Using the dye dilution technic of Hamilton the cardiac output was measured in 20 patients with acute myocardial infarction. The blood pressure, circulation time, venous pressure, plasma volume, and hematocrit were also determined. Those patients who developed congestive heart failure had a low cardiac output and a prolonged circulation time. These changes were more pronounced in seven patients with sustained shock. One patient who had just recovered from circulatory collapse was found to have a cardiac output of 9.3 liters per minute.
Nitric oxide mediates immune dysfunction in the spontaneously hypertensive rat.
Authors: Pascual D W , Pascual V H , Bost K L , McGhee J R , Oparil S
Published: June 2012

The immune system of the spontaneously hypertensive rat is dysfunctional compared with that of normotensive control strains. Previous studies from our laboratory have shown that immunodepression in the spontaneously hypertensive rat was mediated by macrophages. The current study examines the mechanism for the depressed proliferative responses to concanavalin A typically observed by splenic mononuclear cells of spontaneously hypertensive rats. We tested various inhibitors of known macrophage products responsible for suppressing lymphoid function. The nitric oxide synthetase inhibitor NG-monomethyl L-arginine produced dose-dependent derepression of the proliferative responses of splenic mononuclear cells to concanavalin A. In contrast, indomethacin and catalase exhibited only weak derepression of the proliferative responses. Subsequent analysis showed that splenic mononuclear cells from spontaneously hypertensive rats generated greater nitric oxide levels than cells from Wistar-Kyoto rats, and nitric oxide levels were reduced when the inhibitor was added to splenic mononuclear cell cultures from spontaneously hypertensive rats. We further demonstrated that L-arginine is required for the development of the depressed mitogen-induced proliferative responses in these cells. Addition of L-arginine in excess of 10 microM to cultures diminished cell proliferation and increased nitric oxide. Polyclonal antibodies to murine interferon gamma reduced nitric oxide accumulation by approximately 50%, suggesting that interferon gamma is partially responsible for enhancing nitric oxide production in mitogen-stimulated splenic mononuclear cell cultures from spontaneously hypertensive rats. Thus, this study provides evidence that the immune depression observed in the spontaneously hypertensive rat is nitric oxide dependent.
Guanine nucleotide regulatory proteins in the spontaneously hypertensive rat.
Authors: Clark C J , Milligan G , McLellan A R , Connell J M
Published: June 2012

We compared guanine nucleotide regulatory protein (G protein) levels and function in plasma membranes from resistance vessels (mesenteric arteries) isolated from spontaneously hypertensive (SHR) and normotensive Wistar rats. G protein function was deduced from studies of adenylate cyclase activity. Although the basal level of adenylate cyclase activity (+/- Mn2+ ions) was significantly greater in SHR membranes, addition of agents that function via the stimulatory G protein--i.e., NaF (10(-2) M), (-)-isoproterenol (10(-4) M), and prostaglandin E1 (10(-5) M)--resulted in a significantly lower stimulatory response in SHR membranes. Ligands that function via the inhibitory G protein--i.e., adrenaline (10(-5) M)/propranolol (10(-5) M) (this combination being equivalent to an alpha 2-receptor agonist), carbachol (10(-3) M), and serotonin (10(-5) M)--were responsible for only slight inhibitory responses in both SHR and Wistar rat membranes, which were not significantly different. Western blotting identified the presence of Gs, Gi2, and Gi3 alpha-subunits in rat vascular smooth muscle, but there were no differences in the levels of these G protein alpha-subunits found in SHR and Wistar rat plasma membranes. The levels of the beta-subunit in the two sets of membranes were also similar. In conclusion, there is a reduced response in adenylate cyclase activity to agents that function via the stimulatory G protein in SHR membranes. However, this is not a consequence of altered levels of the different G protein subunits.
Surface Markers of Heterogeneous Peripheral Blood–Derived Smooth Muscle Progenitor Cells
Authors: Wang Chao-Hung , Lee Yun-Shien , Lin Shing-Jong , Mei Hsiu-Fu , Lin Sheng-Yuan , Liu Min-Hui , Chen Jim-Ray , Cherng Wen-Jin
Published: June 2012

Objective—

Smooth muscle progenitor cells (SMPCs) were intriguingly shown to act as a double-edged sword in the pathogenesis of atherosclerosis. To fully clarify the roles of SMPCs in atherosclerosis, a distinct panel of SMPC surface markers is mandatory to be developed.

Methods and Results—

Microarray gene expression analyses were used to discover potential surface markers of SMPCs. In vitro and in vivo experiments documented that platelet-derived growth factor receptor-β, carboxypeptidase M, carbonic anhydrase 12, receptor activity-modifying protein 1, and low-density lipoprotein receptor–related protein were the 5 specific surface markers regulating various SMPC functions, including migration, extracellular matrix formation, resistance to hypoxia, and anti-inflammation. In s
evere combined immunodeficiency
/nonobese diabetic mice after femoral arterial wire injury, injected human peripheral blood mononuclear cells contributed to substantial amount of neointimal α-smooth muscle actin-positive cells, coexpressing platelet-derived growth factor receptor-β, carboxypeptidase M, carbonic anhydrase 12, receptor activity-modifying protein 1, and low-density lipoprotein receptor–related protein. Based on these markers, a novel quantification assay was developed to enumerate circulating early SMPC. Early SMPC numbers were higher in patients with unstable angina compared with those with normal coronary angiograms. In patients with acute ST-elevation myocardial infarction, different patterns of serial early SMPC changes were noted, related to different clinical presentations.

Conclusion—

Surface markers of heterogeneous SMPCs exhibit various functions associated with atherosclerotic pathophysiology. Quantification of surface marker–defined SMPCs provides a platform for studying SMPCs in cardiovascular diseases.
Effects of Estrogen on Vascular Inflammation
Authors: Novella Susana , Heras Magda , Hermenegildo Carlos , Dantas Ana Paula
Published: June 2012

Objective—

Our study aims to determine the role of time of menopause on vascular inflammation biomarkers and how it affects their modulation by estrogen and raloxifene in postmenopausal women.

Methods and Results—

Uterine arteries from 68 postmenopausal women were divided into 3 segments and cultured for 24 hours in tissue culture media containing 17β-estradiol (100 nmol/L), raloxifene (100 nmol/L), or vehicle. Assessment of arterial concentration of 13 inflammatory biomarkers was performed by multiplex immunobead-based assay. Aging per se has a positive correlation with the generation of several proinflammatory markers. Although short-term estradiol exposure correlates with lower expression of tumor necrosis factor-α, vascular endothelial growth factor, and interleukin-1β in all age groups, for most biomarkers aging was associated with a switch from a beneficial anti-inflammatory action by estrogen, at earlier stages of menopause, to a proinflammatory profile after 5 years past its onset. Raloxifene has no significant effect on the expression of all proinflammatory markers. Western blot analysis of estrogen receptor expression (estrogen receptor-α and estrogen receptor-β) showed that estrogen receptor-β increases with aging, and this increase has a positive correlation with the generation of several proinflammatory markers.

Conclusion—

Aging alters estrogen-mediated effects on the modulation of inflammatory biomarkers in women. How aging affects estrogen responses on vascular inflammation is not clear, but our data show a positive association between increased estrogen receptor-β expression with aging and proinflammatory effects by estrogen.
Differing Relationship of Nocturnal Fluid Shifts to Sleep Apnea in Men and Women With Heart Failure
Authors: Kasai Takatoshi , Motwani Shveta S. , Yumino Dai , Mak Susanna , Newton Gary E. , Bradley T. Douglas
Published: June 2012

Background—

In men with heart failure, nocturnal rostral fluid shift is associated with an overnight increase in the neck circumference (NC) and with severity of obstructive sleep apnea. Because the prevalence of obstructive sleep apnea is lower in women than in men with heart failure, we hypothesized that less fluid would shift into the neck in association with less severe obstructive sleep apnea in women than in men with heart failure.

Methods and Results—

In 35 men and 30 women with heart failure, we assessed overnight changes in NC (ΔNC) and leg fluid volume before and after polysomnography. The severity of obstructive sleep apnea was assessed by the apnea–hypopnea index. Although the changes in leg fluid volume did not differ significantly between men and women (−131 ± 90 versus −180 ± 132 mL,
P
=0.081), in women, ΔNC was smaller (
P
<0.001) than in men. Furthermore, although in men, changes in leg fluid volume correlated inversely with ΔNC (
r
=−0.755,
P
<0.001) and apnea–hypopnea index (
r
=−0.765,
P
<0.001), it did not in women.

Conclusions—

Despite no difference in overnight displacement of fluid from the legs compared with in men, in women, less of this fluid reached the neck, and unlike men, there was no relationship between changes in leg fluid volume and either ΔNC or apnea–hypopnea index. These findings suggest a differing relationship between overnight fluid shift from the legs and severity of obstructive sleep apnea in women than in men with heart failure.