bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of new self‐learning techniques for the generation of criteria for differentiation of wide‐QRS tachycardia in supraventricular tachycardia and ventricular tachycardia
Authors: Dassen Willem R.M. , Mulleneers Rob G.A. , Smeets Joep L.R.M. , Wellens Hein J.J. , Karthaus Vincent L.J. , Talmon Jan L. 
Published: February 2009

AbstractThis study presents a comparison of three different methods for differentiating between supraventricular and ventricular tachycardias with wide‐QRS complex. One set of criteria, derived using classical statistical techniques, was compared with two new self‐learning computer techniques: the artificial neural networks and the induction algorithm approach. By analyzing the results obtained in an independent test set, using these new techniques, the criteria defined by the classical method could be improved.
Malignant coronary artery disease in young asian indians: Thoughts on pathogenesis, prevention, and therapy
Authors: Enas Enas A. , Mehta Jawahar 
Published: February 2009

AbstractAsian Indians have the highest rates of coronary artery disease (CAD) of any ethnic group studied, despite the fact that nearly half of this group are life‐long vegetarians. CAD occurs early in age and generally follows a malignant course. Although the incidence of classic risk factors is low, high triglyceride and low high‐density lipoprotein cholesterol levels, high lipoprotein(a) levels, hyperinsulinemia, and apple‐type obesity all show a substantial prevalence in this population. Aggressive modification of life style beginning before adolescence seems justified in view of the malignant nature of CAD in this population. Pharmacologic intervention similar to that of secondary prevention of CAD seems justified as primary prevention in high‐risk Asian Indians.
Effects of flecainide on exercise hemodynamics and electrocardiography in patients without structural heart disease
Authors: Wang Jian‐An , Lau Chu‐Pak , Tai Yau‐Ting , Wu Bi‐Zhen 
Published: February 2009

AbstractAlthough exercise testing has been advocated to unmask proarrhythmic potentials in patients receiving flecainide acetate, the effects of this drug on exercise parameters in individuals without structural heart disease have not been reported. This study was undertaken to assess the effects of flecainide on hemodynamics and electrocardiographic changes during exercise testing in 24 patients with paroxysmal supraventricular tachyarrhythmias, who had normal cardiac structure and sinus node function. Paired treadmill exercise tests using the Bruce protocol were performed after 1 week of treatment with flecainide (200 mg/day) or placebo in a double‐blind, randomized design. Exercise testing was terminated because of either fatigue or dyspnea in all subjects. Although resting heart rate was unaffected, flecainide reduced the exercise heart rate (expressed as a percentage of age‐predicted maximum) compared with placebo (84±12% vs. 92±9%, p<0.001). Neither resting and exercise systolic blood pressure nor exercise duration were affected. PR interval shortening with exercise was not affected by flecainide, whereas QRS was prolonged compared with placebo (20±9% vs. 0±8%, p<0.01). Compared with placebo, flecainide significantly shortened QTc (‐7±12% vs. 0±8%, p<0.05) and JTc (‐34±11% vs. ‐21±11%, p<0.01) intervals during exercise. During exercise, flecainide produced significant depression in the sinus node automaticity and manifested use‐dependent slowing of ventricular conduction and acceleration in ventricular repolarization.
Prognostic value of clinical variables for recurrent ischemic events after acute myocardial infarction
Authors: Piombo Alfredo C. , Gagliardi Juan A. , Ulmete Elisabet R. , Ramos Alberto O. , Bertolasi Carlos A. 
Published: February 2009

AbstractRecurrent ischemia after acute myocardial infarction (AMI) has been largely associated with a poor prognosis. This study was carried out to analyze the relationship among different clinical variables and both postinfarction angina and reinfarction after AMI. A total of 452 consecutive patients (mean age 58.2±12 years) were admitted to the coronary care unit and were studied prospectively. More than half of the patients received some type of thrombolytic therapy. Death occurred in 45 patients (9.9%) during hospital stay. Postinfarction angina was diagnosed in 81 patients (17.9%) and reinfarction in 22 (4.9%). Patients who developed reinfarction had a high mortality rate (45.5%) compared with those who did not develop such an event (8.1%) (p<0.0001; odds ratio: 9.4; 95% confidence interval 3.5–25.4). On the other hand, postinfarction angina had no significant association with mortality. Multivariate analysis revealed that a history of angina (> 1 week) was predictive of the occurrence of postinfarction angina and that the use of fibrinolytic treatment, prodromal symptoms, and postinfarction angina were significantly related to reinfarction. We conclude that several simple clinical variables are clear independent predictors of postinfarction angina and reinfarction following AMI and should be taken into account in routine clinical practice or when planning intervention trials.
Localization of a misplaced coronary artery stent by magnetic resonance imaging
Authors: Mohiaddin Raad H. , Underwood Richard , Roberts Robin H. , Rothman Martin 
Published: February 2009

AbstractCoronary artery stents have been developed to overcome arterial abrupt closure and restenosis following balloon angioplasty. Complications of stent insertion include loss of the device from its delivery system into the peripheral circulation. Certain types of stents are almost radiolucent, making localization of the lost devices difficult. Nonferromagnetic metallic biomedical implants induce alteration of the local magnetic field and this leads to loss of signal from the surrounding tissues. We have used this property to localize a misplaced coronary artery stent in a 53‐year‐old man who underwent unsuccessful stent insertion. A 0.5 Tesla magnetic resonance scanner was used to acquire gradient‐echo and spin‐echo images. An in vitro experiment was first carried out on a stent similar to that used in our patient to establish that it was nonferromagnetic and to determine the optimum imaging technique. Gradient‐echo images with a relatively long echo time (22 ms) gave the largest area of signal loss around the stent, and this sequence was used for localization of the stent found in the patient's left profunda femoris artery. This was subsequently confirmed by digital radiography. We have demonstrated the convenience and practicality of using magnetic resonance imaging for the localization of a misplaced coronary artery stent in a patient. The technique is safe, noninvasive, and uses no ionizing radiation.
Sudden cardiac death in patients with hypertrophic cardiomyopathy: From bench to bedside with an emphasis on genetic markers
Authors: Marian Ali J. 
Published: February 2009

AbstractHypertrophic cardiomyopathy (HCM) is the most common cause of death in the young, particularly in young competitive athletes. Death often occurs suddenly in asymptomatic, apparently healthy individuals. Several clinical parameters as well as genetic factors have been characterized that can identify those HCM patients who are at high risk for sudden cardiac death (SCD). The clinical parameters that have some predictive values for SCD in HCM patients are the following: a prior history of SCD, a family history of SCD, history of syncope, symptomatic ventricular tachycardia on Holter monitoring, inducible ventricular tachycardia during electrophysiologic studies, and myocardial ischemia in children with HCM. Recent identification of mutations in the beta myosin heavy chain gene and genotype‐phenotype correlation in HCM patients have shown that the beta myosin heavy chain mutations are also prognosticators in HCM families. Several mutations such as Arg403Gln and Arg719Gln are associated with a high incidence of SCD, while Leu908Val mutation is associated with a benign course and a low incidence of SCD in HCM families. Additional genetic factors such as a polymorphism in angiotensin‐converting enzyme I gene may also contribute to a high incidence of SCD in HCM families. Identification and characterization of HCM patients at high risk for SCD provide the opportunity to render prophylactic therapeutic interventions, such as implantation of defibrillators, in these individuals.
Pathology of tricuspid valve stenosis and pure tricuspid regurgitation—part III
Authors: Waller Bruce F. , Howard Jane , Fess Stephen 
Published: February 2009

AbstractThis three‐part article examines the histologic and morphologic basis for stenotic and purely regurgitant tricuspid valves. In Part III, morphometric analysis of tricuspid valve annular circumference, leaflet area, and the product of annular circumference and leaflet area are shown to be useful in establishing etiology for the purely regurgitant tricuspid valves and in assessing the anatomic basis of pure tricuspid regurgitation in the presence of mitral stenosis.
A case of cardiac sarcoidosis with remarkable atrophy of the left ventricular septum on two‐dimensional echocardiography
Authors: Matsumura Akihiko , Yanase Osamu , Motomiya Takeshi , Tokuyasu Yoshiki , Sakurada Harumizu , Nomura Shuzo , Teshima Tamotsu , Hiyoshi Yasunaga , Sugiura Masaya 
Published: February 2009

AbstractSarcoidosis is a multisystem granulomatous disorder of unknown etiology which mainly affects the lungs, skin, the lymphoreticular system, and the heart. We report a case of cardiac sarcoidosis in which a remarkably thin ventricular septum was demonstrated on two‐dimensional echocardiography.
Dobutamine stress echocardiography for the diagnosis and management of coronary artery disease
Authors: Tanimoto Masato , Pai Ramdas G. , Jintapakorn Woravut , Shah Pravin M. 
Published: February 2009

AbstractInfusion of dobutamine in low and high doses in combination with echocardiography can be used for the assessment of myocardial viability and functional significance of coronary artery disease. Improvement of contractile function of hypokinetic or akinetic ventricular wall segment with low‐dose dobutamine has a high predictive value for the detection of hibernating and stunned myocardium. High‐dose dobutamine stress is of value for noninvasive diagnosis of coronary disease, assessment of its clinical significance, risk stratification of patients after myocardial infarction, preoperative evaluation of patients undergoing major noncardiac surgery, and assessment of the efficacy of coronary revascularization. It has an excellent safety record even in the immediate postmyocardial infarction period.
Initial depolarizing potentials in wolff‐parkinson‐white syndrome using signal‐averaged electrocardiograms: Correlation with reciprocating tachycardia
Authors: Kubo Masahiro , Matsuoka Suguru , Kuroda Yasuhiro 
Published: February 2009

AbstractInitial depolarizing potentials were examined in patients with Wolff‐Parkinson‐White (WPW) syndrome using signal‐averaging techniques. In all, 25 WPW patients and 21 agematched healthy children were studied. Ten of the patients were symptomatic and 15 were asymptomatic. Symptomatic patients with supraventricular tachycardias had longer durations of lowamplitude signals (LAS) < 40 μ V in the initial portion of the QRS complex (initial LAS, 49 ± 7 ms vs. 37 ± 9 ms, p < 0.01) and lower root‐mean‐square (RMS) voltage in the initial 40 ms of the QRS complex (initial RMS, 12 ± 4 μ V vs. 23 ± 8 μ V, p < 0.01) compared with asymptomatic patients. When a symptomatic patient was defined as having an initial LAS of > 46 ms or an initial RMS of < 15 μ V, the sensitivity and specificity for predicting documented supraventricular tachycardia were 100 and 67%, respectively. These SA‐ECG findings may reflect instability of conduction in symptomatic patients through an accessory pathway and may identify those at high risk for supraventricular tachycardia.
Myocardial dysfunction and abnormal left ventricular exercise response in autonomic diabetic patients
Authors: Scognamiglio Roldano , Fasoli Giuseppe , Nistri Stefano , Miorelli Manuela , Egloff Carlo , Buja Gianfranco , Dalla‐Volta Sergio , Fedele Domenico , Ferri Marcello 
Published: February 2009

AbstractIn diabetic patients, the pathophysiologic mechanisms of exercise‐induced left ventricular (LV) dysfunction remain controversial. In this study, the role of myocardial contractility recruitment in determining an abnormal LV response to isometric or dynamic exercise has been investigated in 14 diabetic patients with autonomic dysfunction. Ischemic heat disease was excluded by the absence of LV wall motion abnormalities induced by isotonic and isometric exercise and by coronary angiography. Left ventricular and myocardial function were studied at rest, and during isometric and isotonic exercise, by two‐dimensional echocardiography; moreover, recruitment of an inotropic reserve was assessed by postextra‐systolic potentiation at rest and at peak handgrip. An abnormal response of LV ejection fraction to isometric (9/14) or to dynamic (8/14) exercise was frequent in study patients. In these patients, baseline myocardial contractility was normal, and the significant increase in ejection fraction by postextrasystolic potentiation indicated a normal contractile reserve (65 ± 7% vs. 74 ± 6%, p=0.001). Nevertheless, the downward displacement of LV ejection fraction‐systolic wall stress relationships during exercise suggests an inadequate increase in myocardial contractility. However, the abnormal ejection fraction at peak handgrip was completely reversed by postextrasystolic potentiation (67 ± 6% vs. 58.1 ± 10%, p=0.008), a potent inotropic stimulation independent of the integrity of adrenergic cardiac receptors. A defective inotropic recruitment, despite the presence of a normal LV contractile reserve, plays an important role in deexercise LV dysfunction in diabetic patients with autonomic neuropathy.
Transesophageal echocardiography in the evaluation of cardiac myxoma: A case of familial myxoma
Authors: Kazakis D. James , Lewis Jannet F. , Conti C. Richard 
Published: February 2009

AbstractThe vast majority of atrial myxomas are readily apparent on standard transthoracic echocardiography. We present the case of a young woman with known history of familial myxoma, in whom a large left atrial mass was identified on transthoracic echocardiography. Transesophageal study more clearly delineated the extent and origin of the tumor. In addition, an unsuspected tumor in the right ventricle was also identified. These findings were confirmed at surgery, and both masses were excised. The advantages of transesophageal echocardiography in evaluation and management of this unusual subset of patients with cardiac tumor are discussed.
Beneficial clinical effect of very early enalapril treatment in patients with acute left ventricular failure complicating myocardial infarction
Authors: Hüttl S. , Lehmann K. , Delius W. , Nussberger J. , Brunner H.R. , Hasford J. 
Published: February 2009

AbstractAcute myocardial infarction (AMI) leads to left ventricular dysfunction, the extent of which predicts mortality. We studied the effect of very early enalapril treatment in patients with left ventricular failure (Killip classification II‐III) resulting from AMI. In a double‐blind randomized trial, patients on conventional treatment were started on placebo (PL, n = 15) or 2.5 mg enalapril (EN, n = 15) twice daily as early as 24 to 30 h after AMI and were followed up over a period of 21 days. One patient died in each treatment group. There were three dropouts in the placebo group (progressive heart failure requiring antiotensin‐converting enzyme inhibition) and one dropout in the enalapril group (malignant ventricular arrhythmias). Plasma atrial natriuretic peptide (ANP) and norepinephrine decreased similarly in both groups from elevated baseline concentrations. The patients with the highest baseline ANP levels died in both groups: EN: 579 fmol/ml (mean 65.3 ± 34.4 fmol/ml), PL: 403 fmol/ml (mean 63.5 ± 37.6 fmol/ml). Killip classification improved in 9 of 13 patients on enalapril but only in 5 of 11 patients on placebo. On echocardiography an increase in fractional shortening (FS) (3.2 ± 7.5%, p < 0.05) was found with enalapril only. Patients on placebo required more diuretics, and plasma aldosterone increased threefold. Thus, very early enalapril treatment may help prevent left ventricular failure after AMI. Extremely high initial plasma ANP concentrations may predict an unfavorable outcome.
Right ventricular apical view—A new window for doppler echocardiography of aortic valve stenosis
Authors: Hust Martin H. , Metzler Birgit , Fritz Stephan , Braun Bernd , Röcker Kai , Dickhuth H.‐H. 
Published: February 2009

AbstractWe studied a new Doppler echocardiographic approach in 56 patients with valvular aortic stenosis from the right ventricular apex (AS‐RV) and compared the transvalvular gradients with the results of the standard view from the left ventricular apex (AS‐LV). AS‐RV resulted in good or acceptable velocity curves in 59% of patients. The correlation between the two apical views for the peak/mean gradients were close (r = 0.95/0.96). Using all typical positions for Doppler investigation of aortic stenosis, highest peak gradients were best recorded in five cases by AS‐RV. In one woman with a narrow left ventricular cavum and severe aortic stenosis, only AS‐RV yielded a technically good spectral curve. Thus, in selected patients—probably those with a small left ventricular cavity or an enlarged right ventricle—AS‐RV may be the best window or even the only possibility in Doppler investigation of aortic valve stenosis.
Exercise metabolism during 1 hour of treadmill walking while taking high and low doses of propranolol, metoprolol, or placebo
Authors: Head A. , Kendall M.J. , Maxwell S. 
Published: February 2009

AbstractAerobic exercise and beta‐blocking drugs are regularly prescribed as treatment for hypertension and as a prophylactic for patients at risk from coronary heart disease and for those recovering from an infarct. Some beta blockers, particularly non‐beta1‐selective drugs, may make exercise more difficult, possibly by interfering with substrate metabolism during exercise. This study examined the effects of low and high doses of a beta1‐selective blocker, metoprolol, and a nonselective beta blocker, propranolol, on exercise metabolism. The study involved 20 healthy subjects (10 men, 10 women) who walked on a treadmill at 50% of their maximal oxygen uptake for 1 h on five occasions, separated by 7 days. On each of the five occasions they received one of the following treatments, given in random order: placebo, metoprolol 50 mg, metoprolol 100 mg, propranolol 40 mg, or propranolol 80 mg, all taken twice daily. Fat oxidation, expressed as a percentage of total energy expenditure, was significantly lower than with placebo for all of the active treatments except metoprolol 50 mg (placebo: 42.7 ± 11.6%; metoprolol 50 mg: 38.7 ± 14.1%, p = NS; metoprolol 100 mg: 36.3 ± 13.7%, p = 0.05; propranolol 40 mg: 31.2 ± 9.3%, p = 0.01; propranolol 80 mg: 29.5 ± 10.9%, p = 0.01); and significantly lower with propranolol than with metoprolol (propranolol 40 mg: p = 0.0036; propranolol 80 mg: p = 0.01). Plasma ammonia concentration was significantly higher than with placebo with propranolol 40 mg, propranolol 80 mg, and metoprolol 100 mg (p = 0.01 for all); with metoprolol 50 mg, there was no difference from placebo (p = NS). Both beta blockers in this study reduced fat metabolism and increased perceived exertion to some degree. Additional inhibition of fat oxidation occurred with the nonselective drug, probably in intramuscular rather than adipose lipolysis, and was probably beta2 mediated. The results of this study suggest that a selective beta blocker has less of an adverse effect on substrate metabolism than does a nonselective beta blocker. Beta1‐selective drugs may offer advantages in patients who undertake regular aerobic exercise.
In consecutive patients hospitalized with acute myocardial infarction, infarct location according to routine electrocardiogram is of minor importance for the outcome
Authors: Karlson Björn W. , Herlitz Johan , Hjalmarson Åke 
Published: February 2009

AbstractMost studies have suggested that patients with anterior myocardial infarction have an adverse prognosis compared with patients with inferior infarction. The objective of this study was to compare the mortality and morbidity in anterior versus inferior acute myocardial infarction (AMI) during 1 year in a consecutive series of patients hospitalized with AMI. All patients fulfilling the criteria for AMI who were admitted to a single hospital during 21 months (n = 921) participated in the study. Patients with anterior infarction (n = 312) had a 1‐year mortality rate of 26% versus a rate of 24% for patients with inferior infarction (n = 269) (p > 0.2). The corresponding figures for patients with no previous infarction who developed Q waves were 27 and 21%, respectively (p > 0.2). Reinfarction, thromboembolic events, and other aspects of morbidity during longterm follow‐up appeared with similar frequency in the two groups. Thus, in a nonselected group of patients admitted to a single hospital because of AMI, the prognosis was found to be similar among patients with inferior and those with anterior infarction. In the subset of patients with a first myocardial infarction who developed Q waves, there was a trend indicating higher mortality in anterior infarction.
Long‐Term denopamine therapy for hemodialysis patients with chronic heart failure
Authors: Takata Yutaka , Tsuchihashi Takuya , Nakamura Sadatoshi , Hirota Yasuo 
Published: February 2009

AbstractDenopamine was orally administered for more than 12 months to patients with chronic heart failure on maintenance hemodialysis. The plasma level in subjects treated with denopamine at 30 mg/day tended to be higher than that in subjects on 15 mg/day. There was no gradual increase in plasma level as the duration of therapy prolonged. Left ventricular end‐diastolic and end‐systolic diameters as well as ejection fraction on echocardiography showed a tendency to be improved by denopamine. Similarly, the cardiothoracic ratio was improved temporarily. No adverse effects were detected by electrocardiography and laboratory tests. These observations suggest that denopamine is safe and effective for hemodialysis patients with chronic heart failure.
Progression and regression of coronary artery disease—Linkage of clinical, pathologic, and angiographic findings
Authors: Matsuda Yasuo , Kramer John R. , Matsuda Masako 
Published: February 2009

AbstractProgression and regression of coronary artery disease are analyzed with respect to clinical, pathologic, and angiographic findings. Clinically, progression of coronary artery disease is a highly unpredictable process. The pattern of progression is not linear in time but sometimes is rapid and other times is slow. The atherosclerotic lesion is not pathologically homogeneous. Regression therapies, therefore, might be effective depending on the composition of the lesion and the phase of atherosclerotic evolution. True clinical regression should be concordant with the clinical improvement of symptoms as well as prognosis. Further studies are required to establish the effectiveness of therapy for the prevention of progressive coronary artery disease.