bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coronary artery disease in diabetic and nondiabetic patients: A clinical and angiographic comparison
Authors: Wilson C. S. , Gau G. T. , Fulton R. E. , Davis G. D. 
Published: July 2009

AbstractA comparison of data from 58 diabetic and 58 nondiabetic patients with arteriographic evidence of coronary artery disease showed that diabetic patients had a significantly greater frequency of major stenoses in the intermediate coronary artery segments but no significant differences in the proximal or distal segments. Thus, the diabetic patients did have more severe coronary disease, but the diabetic group did not have “more distal” disease as represented by the number of major or minor lesions in the distal segments. The diabetic patients had a significantly greater frequency of electrocardiographic intraventricular conduction defects and manifestations of left ventricular dysfunction. There was no significant difference in the severity of coronary artery disease between the diabetic patients with manifestations of myocardial decompensation and the diabetic patients without such manifestations, suggesting that the in‐creased frequency of myocardial dysfunction in diabetic patients may be related to factors other than the greater severity of coronary artery disease.
A new microcomputer‐based ecg analysis system
Authors: Kyle M. C. , Conrad J. D. , Freis E. D. , Klingeman J. D. , Pipberger H. V. 
Published: July 2009

AbstractA new automated ECG system using advances in microprocessor technology and computerized electrocardiography is described. This microcomputer‐based system is self‐contained and mobile. It acquires both the 12‐lead and orthogonal lead (Frank) electrocardiograms and analyzes the latter within minutes. Software includes the program developed in the Veterans Administration which uses advanced statistical classification techniques and a large well‐documented patient data base. Diagnostic probabilities are computed using a Bayesian approach. Diagnostic performance has been tested using independent clinical criteria and found to be quite accurate. This system enables the clinician to immediately review the computer's identifications, measurements, and diagnostic classifications and quickly use these results in clinical decision making. Serial comparisons are readily made since all previous recordings are stored on floppy diskettes. The use of microprocessors in this system makes it economically feasible for practicing physicians.
Acute myocardial infarction with normal coronary arteries. in vivo demonstration of coronary thrombosis during the acute episode
Authors: Fernandez M. S. , Pichard A. D. , Marchant E. , Lindsay J. 
Published: July 2009

AbstractTwo cases with acute myocardial infarction are presented. Both had thrombotic occlusion of the infarct‐related artery. Following successful thrombolysis with streptokinase, coronary angiography was normal. These cases prove that “myocardial infarction with normal coronaries” can be associated with coronary thrombosis in the acute stage.
Terminology and anatomy of angulated coronary arteriography
Authors: Grover M. , Slutsky R. , Higgins C. , Atwood J. E. 
Published: July 2009

AbstractAngulated views in coronary arteriography have been increasingly utilized because of their superiority in demonstrating lesions not well seen in standard right and left oblique projections. The importance of these angulated views has been repeatedly demonstrated. It is the purpose of this article to review some basic coronary anatomy angulation terminology, and then to describe the particular advantages of the angulated views in coronary arteriography. Illustrations of these particular views of both coronary systems will be provided.
Altered platelet alpha2adrenoreceptors in orthostatic hypotension
Authors: Weiss R. J. , Dix B. R. , Kissner P. Z. , Smith C. B. 
Published: July 2009

AbstractAlpha2adrenergic agonists have been used to raise blood pressure in patients with idiopathic orthostatic hypotension (IOH). In an attempt to define the mechanism of action of these agents, radioligand binding of [3H]clonidine, an alpha2agonist, and of [3H]yohimbine, an alpha2antagonist, to human platelet membranes from a patient with IOH was performed to determine the maximum number (Bmax) and dissociation constant (Kd) for this receptor. There was a marked decrease in receptor number in this patient when compared to normal subjects. In normal volunteers the specific binding of [3H]clonidine yielded a mean Bmax of 33 ±2 fmol/mg protein and a Kd of 5.5±0.6 nM, while for the patient the Bmaxwas 20 fmol/mg protein and the Kd was 7.4 nM. For [3H]yohimbine binding in normals, the Bmax was 165 ±12 fmol/mg protein and the Kd was 4.0±0.5 nM, whereas for the patient the Bmaxwas 65 fmol/mg protein and the Kd was 12.0 nM. Alpha2adrenergic agonists such as clonidine decrease blood pressure by stimulating central presynaptic alpha2sites, and thus inhibiting sympathetic activity. There are also alpha2adrenergic receptor sites postsynaptically on vascular smooth muscle. The presence of this receptor postsynaptically in a patient with a reduction of the presynaptic inhibitory sites could account for clonidine's pressor activity in patients with IOH. Further study of both alpha2‐adrenergic receptors in patients with IOH may be important in developing an understanding of central and peripheral mechanisms in the control of blood pressure.
Value of exercise electrocardiography to predict additional jeopardized myocardial regions remote from site of previous myocardial infarction
Authors: Bamrah V. S. , Ryan P. A. , Ptacin M. J. , Tristani F. E. 
Published: July 2009

AbstractIn order to evaluate the efficacy of exercise electrocardiography (ECG) to identify jeopardized myocardial regions remote from the site of previous infarction, exercise ECG, left ventriculography, and coronary arteriography were performed in 90 patients with previous transmural myocardial infarction (MI). Of the 90 patients, angiographic studies revealed jeopardized myocardial regions in 47 patients. Exercise ECG correctly identified 32 of these 47 patients for a sensitivity value of 68%. There were 43 patients without any additional jeopardized myocardial regions. Exercise ECG correctly identifed only 24 of these 43 patients for a specificity value of 56%. The sensitivity and specificity values were similar in patients with prior anterior and inferior wall MI. It is concluded that relatively low sensitivity and specificity values preclude the ability of exercise ECG to accurately identify patients with jeopardized myocardial regions distant from the site of previous MI. Moreover, when such patients were correctly detected, exercise ECG was rather poor in localizing these additional jeopardized myocardial areas.
24‐hour blood pressure recording in patients with orthostatic hypotension
Authors: Brevetti G. , Chiariello M. , Bonaduce D. , Canonico V. , Breglio R. , Condorelli M. 
Published: July 2009

AbstractContinuous intra‐arterial blood pressure measurement and electrocardiograms were obtained in two ambulatory patients with orthostatic hypotension due to autonomic dysfunction. Systolic and diastolic arterial pressure presented marked variations which took place mainly during the day and were related to several physical activities; however, marked falls in blood pressure were also observed during sleep and at the monent of arousal. A peak incidence of hypotensive events was found in the afternoon, mainly in the hours following the afternoon meal. Recording was repeated after 3 weeks of treatment with propranolol, 40 mg t.i.d. In patient 1, beta blockade drastically reduced the number and severity of hypotensive episodes, while propranolol failed to control blood pressure in patient 2, who experienced a higher number of hypotensive events during treatment. Findings of this study may be relevant to the management of patients with orthostatic hypotension and should contribute to a more accurate characterization of blood pressure profile in autonomic dysfunction.
Management of patients after thrombolytic therapy for acute moycardial infarction
Authors: Goldberg R. K. , Levine S. , Fenster P. E. 
Published: July 2009

AbstractThe coronary artery thrombus that causes acute myocardial infarction can be lysed, and reperfusion can be achieved, in the first few hours after infarction. However, the infarct vessel will reocclude in 15–30% of patients, and this event is frequently associated with pain, reinfarction, arrhythmias, or death. The risk of reocclusion is greatest in patients with high‐grade residual stenosis after thrombolysis. Percutaneous coronary an‐gioplasty may be performed safely after thrombolytic therapy. Angioplasty effectively decreases the degree of residual stenosis, and may thereby reduce the risk of reocclusion and consequent ischemic events. However, a substantial proportion of patients with acute infarction are not suitable candidates for angioplasty. Coronary artery bypass surgery has also been safely performed within several days after thrombolytic therapy. Further studies are needed to determine which patients will benefit most from this aggressive approach to acute myocardial infarction.
The usefulness of exercise‐induced QRS axis shift as a predictor of coronary artery disease
Authors: Ogino K. , Fukugi M. , Hirai S. , Kinugawa T. , Hoshio A. , Hasegawa J. , Kotake H. , Mashiba H. 
Published: July 2009

AbstractThe QRS axis of 101 patients with coronary artery disease (CAD) and 57 normal subjects without CAD who underwent coronary arteriograms were measured before and after exercise testing. There was no improvement in the sensitivity of positive axis shifts (15 degrees or greater) for CAD (18%) when compared to the value of positive ST depression (61%). However, the specificity of positive axis shifts for CAD was significantly increased (98%) when compared to the value of positive ST depression (77%). In addition, 39% of those patients with CAD (39 of 101) showed false negative ST depression, but 18% of these patients (7 of 39) showed a positive axis shift. In normal subjects 21% (12 of 57) showed false positive ST depression, but all of the 21% (12 of 12) showed negative axis shift. There was no significant difference in the increments of heart rate between positive ST depression, positive axis shift, and negative ST depression, negative axis shift. No statistical differences in the sensitivity of ST depression and an axis shift for one‐, two‐ and three‐vessel diseases were noted. The specificity of left‐axis shift for the left anterior descending artery lesion was 98% and the specificity of right‐axis shift for the right coronary artery and/or left circumflex artery lesion was 91%. Therefore, the axis shift response is no more sensitive for the detection of CAD than ST depression. However, when a positive axis shift is observed, one can predict two things: the CAD and the localization of the coronary stenosis.
Quantitative grading of exercise stress test for patients with coronary artery disease using multivariate discriminant analysis
Authors: Wasir H. S. , Dev V. , Narula J. , Bhatia M. L. 
Published: July 2009

AbstractA group of 111 male patients who had undergone maximal or symptom‐limited maximal exercise stress testing for evaluation of coronary artery disease (CAD) were subjected to coronary angiography. Group I comprised 33 patients with normal or single‐vessel disease (SVD), while 78 patients with double‐vessel disease (DVD) or triple‐vessel disease (TVD) formed Group II. On univariate analysis of the exercise test, the following variables were found to be of significance in discriminating between the two groups: age, exercise duration, double product (heart rate × systolic blood pressure) at peak exercise, duration of ST‐segment depression, number of leads showing ST depression, ST depression of 1 mm or more, configuration of the depressed ST segment, and diastolic blood pressure response to exercise. Multivariate analysis however revealed that only the following five variables had significant discriminant power: number of leads showing ST depression, exercise duration, double product, diastolic pressure response, and ST‐segment configuration. On the basis of their relative importance, a regression equation was developed to give a quantitative score to individual patients. A score of less than zero detected multivessel disease (MVD) with high specificity (94%) and sensitivity (70%), while a score of 15 or more almost excluded MVD (sensitivity 87%). The scoring system as reported here improved the exercise stress test interpretation when compared with the conventional reporting system.
Chronic mexiletine therapy for suppression of ventricular arrhythmias
Authors: Duke M. 
Published: July 2009

AbstractOne hundred patients with a 70% or greater reduction of ventricular premature contractions (VPCs) from baseline during 12 weeks of mexiletine therapy were continued on treatment for an additional 9 months. Fifteen patients did not have follow‐up examinations. The response of the remaining 85 patients during this extended period of open‐label mexiletine administration is described. Holter recordings were scheduled at 3‐month intervals during this period. At these examinations, between 69 and 80% of patients maintained the same 70% or greater level of VPC suppression observed at the start of the 9‐month treatment period. Mean and median levels of VPCs/h at each examination were significantly reduced from premexiletine levels throughout the study (p<0.0001). Blood tests and electrocardiographic intervals did not vary. The most frequently used dosage of mexiletine during each 3‐month treatment period was 600 mg/day (50.0‐55.6% of patients). Side effects warranted discontinuation of therapy in 8% (8/97) of patients, while in 25% (22/85), clinical evaluation resulted in a change in dosage level. Within a setting similar to that of clinical practice, long‐term mexiletine administration for non‐life‐threatening ventricular arrhythmias was effective and well tolerated.
Microcomputer‐assisted filing system of cardiac catheterization records using a relational database management system
Authors: Mohri M. , Kikuchi Y. , Sagara T. , Sugihara M. 
Published: July 2009

AbstractTo efficiently store and retrieve cardiac catheterization records, we have developed a computer‐assisted database, which comprises a 16‐bit microcomputer with dual floppy disk drives, a 20 MB random‐access memory, hard disk drive, and a line printer. All program‐mings were accomplished using a relational database management system (R:base 5000, Microrim, Inc.). Data inquiry procedures could be performed with direct operational commands of the system as well as with preprogrammed command files, and final results of searches were printed out with a line printer. The major advantages of the present system described in this report include: (1) the relatively easy and rapid creation of the database, (2) ease of modification of the database structures even after the system design is finished, (3) operational commands in combination with conditional opera‐torts) are flexible and powerful enough to allow the end user to retrieve data based on various kinds of criteria, (4) a high‐level programming language provided by the R:base automates a series of database procedures with relative ease, (5) relational capabilities of the database management system can enhance the possibility of reconstruction of a new data file from a single or several preexisting data files, and (6) the system can be realized at reasonable cost.
Long‐Term morbidity in patients where the initial suspicion of myocardial infarction was not confirmed
Authors: Herlitz J. , Hjalmarson R. , Karlson B. W. , Nyberg G. 
Published: July 2009

AbstractThe morbidity and mortality during a 5‐year follow‐up in thcoronary care unit with chest pain presenting an initial suspicion of acute infarction, but in whom the diagnosis could not be confirmed, is reported. They were divided into four groups: Possible myocardial infarction (29%), angina pectoris (24%), chest pain of uncertain origin (32%), and nonischemic cause of chest pain (15%). The overall 5‐year mortality rate was 13.3 % and did not differ substantially between the four groups. During the 5‐year follow‐up a confirmed myocardial infarction developed in 28% and 22% among patients with the diagnosis possible infarction and angina pectoris, respectively, and in about 10% of the remaining patients. Stroke developed in 4% of patients with possible infarction and in 2‐3% in the remaining subgroups. In all, 59% of the patients were rehospitalized for a mean duration of 30 days in hospital. Among survivors at 5 years, 54% reported chest pain equivalent to angina pectoris and 25% had chest pain daily. A high prevalence of angina pectoris, a high frequency of rehospitalization due to chest pain, and a high consumption of cardiovascular drugs could be found in all four groups.
Prognostic implications of cardiac scintigraphic parameters obtained in the early phase of acute myocardial infarction
Authors: Suzuki A. , Matsushima H. , Satoh A. , Hayashi H. , Sotobata I. 
Published: July 2009

AbstractA cohort of 76 patients with acute myocardial infarction was studied with infarct‐avid scan, radionuclide ventriculography, and thallium‐201 myocardial perfusion scintigraphy. Infarct area, left ventricular ejection fraction, and defect score were calculated as radionuclide indices of the extent of myocardial infarction. The correlation was studied between these indices and cardiac events (death, congestive heart failure, postinfarction angina, and recurrence of myocardial infarction) in the first postinfarction year. High‐risk patients (nonsurvivors and patients who developed heart failure) had a larger infarct area, a lower left ventricular ejection fraction, and a larger defect score than the others. Univariate linear discriminant analysis was done to determine the optimal threshold of these parameters for distinguishing high‐risk patients from others. Radionuclide parameters obtained in the early phase of acute myocardial infarction were useful for detecting both patients with grave complications and those with poor late prognosis during a mean follow‐up period of 2.6 years.
Reevaluation of digoxin‐encainide interactions using an animal model
Authors: Weinhouse E. , Tribble J. , Jarenwattananon M. , Nudel D. B. 
Published: July 2009

AbstractThe effects of intravenous encainide on digoxin‐induced atrial ectopic tachycardia (AET) were investigated in the rat using 3‐channel simultaneous limb‐lead electrocardiography. Pentobarbital‐anesthetized (35 mg/kg, intraperitoneal) adult male rats were given digoxin subcutaneously, 30 mg/kg. After onset of AET, rats received either saline (0.5 ml/kg) or encainide; 0.25, 0.5, 1.0, or 2.0 mg/kg intravenously in repeated doses at 15‐min intervals. At all doses, encainide converted digoxin‐induced AET to ventricular arrhythmias, prolonged recovery time, and increased mortality in comparison to saline‐treated animals. An additional group of anesthetized rats was not given digoxin. These animals received encainide (2.0 mg/kg, intravenously) in repeated doses at 15‐min intervals and developed dose‐related increases in the P‐R interval only. Blood samples were obtained by cardiac puncture from 12 additional anesthetized, digoxin‐treated rats 5 min after the fourth intravenous dose of saline (0.5 ml/kg, n=6) or encainide (1.0 mg/kg, n = 6). Serum was prepared and analyzed by affinity column‐mediated immunoassay. Digoxin levels were the same in both groups. These results suggest that encainide may exacerbate digoxin‐induced arrhythmias (proarrhythmic effect) in this species. In view of our findings of digoxin‐encainide interactions in the rat, we recommend caution if these drugs are coadministered in humans.
Release of adenosine and lactate from human hearts during atrial pacing in patients with ischemic heart disease
Authors: Haneda T. , Ichihara K. , Abiko Y. , Onodera S. 
Published: July 2009

AbstractThirty‐eight patients treated by atrial pacing were divided into three groups (Group I, patients with neither coronary stenosis nor anginal pain during pacing; Group II, patients with no coronary stenosis but having anginal pain during pacing; Group III, patients with coronary stenosis). The concentrations of adenosine and lactate were measured in the coronary sinus blood and in the arterial blood before, during, and after atrial pacing. During atrial pacing, significant levels of adenosine were released from the heart of patients in Group III, whereas significant lactate release was observed in Groups II and III. In Group II, the concentration of adenosine in coronary sinus blood appeared to increase during pacing, but not significantly. There was no significant correlation between the release of adenosine and that of lactate. A significant release of adenosine due to atrial pacing may be observed only in patients with coronary artery disease.
Neurohumoral activation in congestive heart failure: A double‐edged sword?
Authors: Mann D. L. , Cooper G. 
Published: July 2009

AbstractThe search for the basic mechanism(s) responsible for the progressive and frequently irreversible deterioration of left ventricular pump function in congestive heart failure has been quite extensive; nonetheless, no single explanation has been forthcoming. Indeed, given the complexity of this disease process, it is becoming increasingly unlikely that a single pathogenetic mechanism will ever be uncovered for congestive heart failure. This review will examine recent experimental and clinical evidence which suggests that excessive adrenergic stimulation of the heart is double‐edged. That is, while increased adrenergic input to the heart may initially enable the failing myocardium to function adequately for a period of months to years, continued excessive adrenergic stimulation of the heart through both local neural and circulating catecholamines may lead to frank myopathic effects on the heart, with resultant worsening of left ventricular function and the development of intractable congestive heart failure. While we do not mean to suggest that excessive sympathetic stimulation of the heart is the only, or even the major mechanism responsible for the development of irreversible congestive heart failure, the data reviewed herein do suggest that adrenergic stimulation may play a primary role in the pathogenesis of congestive heart failure.
Symptomatology and quality of life in patients with rate‐responsive pacemakers: A double‐blind, randomized, crossover study
Authors: Lau C.‐P. , Rushby J. , Leigh‐Jones M. , Tam C. Y. F. , Poloniecki J. , Ingram A. , Sutton R. , Camm A. J. 
Published: July 2009

AbstractAlthough the hemodynamic advantages of rate‐responsive (RR) pacing are well established, the symptomatic benefits remain controversial and the effects on the quality of life have not been assessed. Sixteen patients with RR pacemakers and a mean age of 56 (range 22–77) years were involved in a double‐blind crossover study to assess their exercise capacity (treadmill testing), symptomatology, and quality of life (structured questionnaires). Pacemakers were implanted because of symptomatic heart block or sick sinus syndrome. Ventricular demand pacemakers were randomly programmed into the constant rate (VVI) or RR pacing modes for four‐week study periods. All patients exercised longer in the RR mode than in the VVI mode (570±29 vs. 437±17 s, p<0.001). Statistically significant improvements in “shortness of breath” and “energy during daily activities” as measured by a 10‐point scale were reported in the RR pacing mode by the patients and were also observed by their close relatives. Symptoms such as “chest pain” and “palpitations” were not worsened during RR pacing. Nondisease‐specific “quality of life” was studied in 11 patients using the Nottingham Health Profile which showed a trend for an improved quality of life in five of the six dimensions of perceived health, although none of the changes were statistically significant. This study suggests that RR pacing should be recommended in selected patients on symptomatic grounds.