bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnosis of silent myocardial ischemia using ambulatory electrocardiographic monitoring with pedometer, analysis of heart rate, and ST loop in ambulatory electrocardiogram
Authors: Ino‐Oka Eui , Takahashi Takashi , Sagawa Kouichi , Inooka Hikaru 
Published: August 2009

AbstractBackground: It has been suggested that episodes of silent myocardial ischemia (SMI) might influence the prognosis of patients with ischemic heart disease, as its consequences are similar to those of myocardial ischemia accompanied by pain. Ambulatory electrocardiogram (ECG) is generally employed in diagnosis as well as in evaluation of clinical efficacy in patients with SMI, but problems related to its application remain because of the difficulty in differentiating between nonischemic and ischemic ST‐segment depressions and because of the absence of data concerning body movement.Methods and results: We developed a method for simultaneously recording onto magnetic tape both the ECG chart and pedometer count, as well as a program which enables semi‐automatic analysis of the heart rate (HR)‐ST relationship. This new method was employed to record ambulatory ECG along with pedometer count for a total of 70 patients, consisting of 53 with coronary heart disease who were shown to have ischemic heart disease, and 17 with various heart diseases in whom coronary angiography revealed no coronary stenosis. The HR‐ST relationship was assessed for periods during which steps were recorded by the pedometer, that is, when patients were confirmed to have been under exertion effort. Patients demonstrating the following findings were diagnosed as true positive for SMI: the ST segment level did not decline until HR increased to a certain threshold, and the rate of change in the ST‐segment level noted thereafter was −0.025 mm/beats/min or lower; or the ST‐segment depression induced by effort continued even after discontinuation of exercise, after which time HR began to decrease, and the HR‐ST loop consequently described a counterclockwise rotation. Evaluation of the HR‐ST relationship based on these criteria revealed excellent results, as demonstrated by values of 79.2% for sensitivity and 94% for specificity.Conclusion: Our newly developed method of assessment of the HR‐ST relationship via analysis of simultaneous data from an ambulatory ECG and a pedometer appears to be time saving, highly objective, and useful with regard to the diagnosis of SMI and evaluation of the therapeutic effect of drugs in patients with ischemic heart disease.
Increased serotonin release across the coronary bed during a nonischemic interval in patients with vasospastic angina
Authors: Murakami Yo , Ishinaga Yuji , Sano Kazuya , Murakami Rinji , Kinoshita Yoshihisa , Kitamura Jun , Kobayashi Kanako , Okada Seiji , Shimada Toshio , Morioka Shigefumi , Matsubara Kazuo 
Published: August 2009

AbstractBackground: Platelet activation and coagulation abnormality have been observed during coronary spasm. It is crucial whether platelet activation occurs even during a nonischemic period.Hypothesis: This study was designed to determine whether platelets might be activated across the coronary bed during a nonischemic interval in patients with vasospastic angina.Methods: Plasma levels of serotonin, 6‐keto‐prostaglandin F1 α, and catecholamines in the aorta and the coronary sinus were simultaneously measured in 16 patients with vasospastic angina and 13 control patients with nonischemic heart disease.Results: None of these patients showed myocardial ischemia during sampling. The difference in transcardiac plasma levels of serotonin in patients with vasospastic angina was significantly higher than that in controls (1.48 ± 1.08 ng/ml vs. 0.07 ± 0.12 ng/ml, respectively, p<0.001). Coronary sinus plasma norepinephrine levels in these two groups were almost the same (204.8 ± 110.8 pg/ml vs. 190.4 ± 131.6 pg/ml, respectively). The ratio of 6‐keto‐prostaglandin F1 α in the coronary sinus and the aorta was not different between the two groups (1.17 ± 0.96 in patients with vasospastic angina vs. 1.15 ± 0.68 in controls).Conclusions: These data suggest that platelet activation across the coronary bed should be ascribed to endothelial dysfunction. Lack of compensatory enhancement of prostacyclin production might be concerned with dysfunction of coronary endothelial cells in these patients.
Effect of nipradilol on silent myocardial ischemia, plasma beta‐endorphin, and bradykinin in chronic stable angina
Authors: Takase Bonpei , Kurita Akira , Uehata Akimi , Hikita Hiroyuki , Nishioka Toshihiko , Mitani Hideki , Satomura Kimio , Mizuno Kyoichi , Nakamura Haruo 
Published: August 2009

AbstractHypothesis: This study was undertaken to investigate the effect of nipradilol on the total ischemic burden and on plasma levels of beta‐endorphin and bradykinin.Methods: Sixteen patients with chronic stable angina were subjected to exercise treadmill testing and 24‐h ambulatory electrocardiogram (ECG).Results: Nipradilol significantly decreased both mean heart rate and mean pressure rate product at submaximal and maximal exercise. It significantly improved exercise‐induced maximal ST‐segment depression from −2.7 ± 0.5 mm to −1.3 ± 0.6 mm (p<0.05) and reduced the number of leads with significant ST‐segment depression (4.0 ± 1.2 vs. 2.0 ± 1.8, p<0.05). Silent ischemic episodes recorded in 24‐h ambulatory ECG were significantly decreased by nipradilol administration, concomitantly with a decrement of mean heart rate and observed maximal heart rate. Patients with exercise‐induced silent myocardial ischemia showed significantly increased plasma levels of beta‐endorphin during both the placebo and nipradilol phases of the study. However, during the nipradilol phase, bradykinin did not change significantly at rest and at peak exercise.Conclusion: Nipradilol effectively controls exercise‐induced myocardial ischemia and silent myocardial ischemic episodes, and does not influence the response of plasma levels of beta‐enduced silent myocardial ischemia.
Higher level of plasma cholesteryl ester transfer activity from high‐density lipoprotein to Apo B‐containing lipoproteins in subjects with angiographically detectable coronary artery disease
Authors: Hibino Takeshi , Sakuma Nagahiko , Sato Takaaki 
Published: August 2009

AbstractBackground and hypothesis: Plasma high‐density lipoprotein cholesterol (HDL‐C) levels correlate inversely with the incidence of coronary artery disease. In order to ascertain whether the transfer activity is related to coronary atherosclerosis, we studied plasma cholesteryl ester transfer activity (CETA) from HDL to apo B‐containing lipoproteins in a consecutive series of 64 Japanese men aged <60 years who had undergone diagnostic coronary angiography.Methods: The subjects were divided into two groups: those who had ≥50% luminal stenosis in one or more coronary arteries (Group 1) and those who had <50% stenosis (Group 2).Results: CETA was 20.8±6.0%/2h in 38 subjects in Group 1. significantly higher than 17.4±6.9%/2h in 26 subjects in Group 2(p<0.05). Plasma HDL‐C levels in Group 1 were significantly lower than those in Group 2(p<0.05). CETA correlated inversely with HDL‐C levels (r = −0.46, p<0.001). Plasma total cholesterol, low‐density lipoprotein cholesterol (LDL‐C), triglyceride (TG), and Lp(a) levels did not differ significantly between the two groups. There was no significant correlation between CETA and either LDL‐C or TG levels.Conclusion: Results suggest that high CETA is realted to low plasma HDL‐C levels and may lead to the development of coronary atherosclerosis. Also, CETA was independent of plasma LDL‐C or TG levels.
Preoperative cardiac risk assessment with adenosine stress dual‐isotope myocardial single‐photon emission computed tomography
Authors: Maunoury Christophe , Stone David A. , Chen Charles C. , Plotnick Gary D. , Holder Lawrence E. 
Published: August 2009

AbstractBackground: Previous studies have demonstrated that pharmacologic stress thallium‐201(201Tl) myocardial scintigraphy is a useful tool to evaluate preoperative cardiac risk.Hypothesis: The purpose of this study was to assess the utility of adenosine stress dual‐isotope [rest 201Tl/stress technetium‐99m (99mTc) sestamibi] myocardial single‐photon emission computed tomography (SPECT) in predicting the risk of perioperative cardiac events (unstable angina, myocardial infarction, cardiac death) in patients undergoing major noncardiac surgery.Methods: We evaluated 43 consecutive patients (20 men, 23 women, mean age 64 years, range 30‐83 years) within 8 weeks prior to major noncardiac surgery requiring general anesthesia. SPECT imaging was performed with 111 MBq (3 mCi)201Tl at rest and 925 MBq (25 mCi)99mTc sestamibi during adenosine stress.Results: Of the 43 patients, 15 (35%) had stress‐induced ischemia and 28 (65%) did not. Perioperative cardiac events occurred in 4 (27%) of the 15 patients with stress‐induced ischemia (2 unstable angina, 2 nonfatal myocardial infarctions) and in none of the 28 patients without inducible ischemia (p = 0.02).Conclusion: Adenosine stress dual‐isotope myocardial SPECT is useful in determining the preoperative cardiac risk of patients undergoing major noncardiac surgery.
The yield of head‐up tilt testing is not significantly increased by repeating the baseline test
Authors: Pavri Behzad B. , Ruskin Jeremy N. , Brooks Ross 
Published: August 2009

AbstractBackground and hypothesis: Head‐up tilt is widely used in evaluating patients with syncope. Data suggest that baseline tilt without isoproterenol is associated with few ≤ 10%) positive results in normals. However, there is considerable day‐today variability in patients with syncope, resulting in low reproducibility. We hypothesized that repeating the baseline tilt would increase the total number of positive responses.Methods: In all, 193 patients with syncope of unknown etiology prospectively underwent serial baseline tilt (Tilt‐1 and Tilt‐2) at 70° for 25 min on two consecutive days.Results: Of 193 patients, 39(20%) had a positive Tilt‐1. Of these, 19 had a positive Tilt‐2, (positive concordance rate: 19/39 = 49%). Of 154 patients with a negative Tilt‐1, 145 had a negative Tilt‐2 (negative concordance rate: 142/151=94%). Only 9 of 154 patients (6%) with a negative Tilt‐1 had a positive Tilt‐2. Thus, the yield increased from 20% (39/193) after Tilt‐1, and to 25% (48/193) after Tilt‐1 plus Tilt‐2, p = NS.Conclusions: (1) Reproducibility of a positive Tilt‐1 is moderate. (2) Reproducibility of a negative Tilt‐1 is high. (3) Repetition of tilt in patients with a negative Tilt‐1 does not significantly increase the number of positive results.
Cost‐effective management of chronic stable angina
Authors: O'Rourke Robert A. 
Published: August 2009

AbstractIn certain patients with stable angina who are at moderate to high risk, coronary bypass surgery or coronary angioplasty are the therapeutic options of choice. However, in selected other patients the use of anti‐ischemic drug therapy and secondary prevention reduce episodes of myocardial ischemia and result in a good long‐term prognosis. Factors affecting management include the extent of coronary disease, the magnitude of cardiac symptoms, the severity of myocardial ischemia and of left ventricular function. Based upon these and other clinical characteristics, patients can be divided into low‐, moderate‐, or high‐risk categories for morbidity and mortality. Patients at high risk are more likely to be selected for myocardial revascularization and patients at low risk are often treated with medical therapy, at least initially. Based on the available cost‐effectiveness data, medical therapy or coronary angioplasty are the preferred initial strategies for low‐risk coronary disease, whereas coronary bypass surgery (CABG) is recommended for many high‐risk patients, particularly for those with triple‐vessel disease and impaired left ventricular function or ischemia at a low workload. CABG is cost‐effective for patients with severe angina and left main coronary artery disease and also for patients with mild angina and triple‐vessel disease. Coronary angioplasty is cost‐effective for patients with severe angina, and single‐ or multivessel disease. In patients with lesser symptoms and mild coronary disease, the cost effectiveness of myocardial revascularization therapy is less likely to be as good as it is in patients with more extensive disease and severe symptoms.
Chronotropic incompetence—Part II: Clinical implications
Authors: Camm A. John , Fei Lü 
Published: August 2009

AbstractThe definition of chronotropic incompetence as inadequate chronotropic response to metabolic demand is, in theory, quite satisfactory. However, the method used in clinical practice for determination of chronotropic incompetence is far from established. The determination of chronotropic incompetence has important diagnostic, therapeutic, and prognostic implications although the exact mechanism underlying chronotropic incompetence is at present unclear. From a pacing viewpoint, chronotropic incompetence is clinically relevant only when there is a functional improvement associated with rate‐responsive pacing. Rate‐responsive pacing has improved the physiologic approach to artificial pacing.
Nonatherosclerotic causes of coronary artery narrowing—Part I
Authors: Waller Bruce F. , Fry Edward T. A. , Hermiller James B. , Peters Thomas , Slack John D. 
Published: August 2009

AbstractApproximately 5% of patients with acute myocardial infarction do not have atherosclerotic coronary artery disease but have other causes for their luminal narrowing. The first part of this three‐part review of nonatherosclerotic causes of coronary narrowing focuses on congenital coronary artery anomalies, coronary fistula, and high take‐off position of coronary ostia.
Uncommon etiologies of atrial fibrillation
Authors: Raggi Paolo , Vasavada Balendu C. , Parente Thomas , Prasada Sudhir , Sacchi Terrence J. 
Published: August 2009

AbstractA newly diagnosed atrial fibrillation warrants a full investigation of the etiopathogenesis of this common arrhythmia. In the adult population, the most frequently associated conditions are systemic hypertension, coronary artery disease, mitral valvulopathy, congestive heart failure, and hyperthyroidism. Nevertheless, more infrequent and even rare, yet correctable, etiologies should not be overlooked. We describe three patients who presented to our hospital with a first episode of atrial fibrillation and who subsequently were demonstrated to have very unusual cardiovascular pathologies subtending this common arrhythmia. In all three cases, transesophageal echocardiography was instrumental in reaching an accurate diagnosis that was later confirmed at surgery.
Constrictive pericarditis causing extrinsic mitral stenosis and a left heart mass
Authors: Pai Ramdas G. , Wong Sammy , Tarazi Riyad 
Published: August 2009

AbstractConstrictive pericarditis is a fibrotic process involving both layers of the pericardium and is known to give rise to obstruction to blood flow in the right heart. We report a patient with constrictive pericarditis who had echocardiographic features of mitral stenosis caused by a fibrocalcific mass lesion involving the mitral annulus with infiltration into the base of the posterior mitral leaflet. To our knowledge, this has not been reported in the literature.
Electrocardiographic evidence of ischemia during ventricular paced rhythms
Authors: Diaz Claro F. , Ganim Mazen S. , Ellestad Myrvin H. 
Published: August 2009

AbstractExercise‐induced electrocardiographic (ECG) changes are the most widely recognized noninvasive means for detecting myocardial ischemia. The specificity of these changes depends on the normalcy of the resting ECG. Right ventricular pacing produces major QRS and ST‐T changes very similar to those of complete left bundle‐branch block. They alter the resting ECG such that ischemic changes are considerably difficult to detect. Because of these resting abnormalities, ECG changes during treadmill exercise testing usually do not facilitate the diagnosis of ischemia or coronary artery disease. The following are two cases of ischemic ECG changes that occurred during right ventricular pacing. To our knowledge, there have been no reports of the classic ECG changes of ST‐segment depression suggestive of ischemia which occurred during right ventricular pacing and which were discemible from the resting ECG changes.
Monocyte‐endothelial cell interaction in atherogenesis and thrombosis
Authors: Ikeda Uichi , Takahashi Masafumi , Shimada Kazuyuki 
Published: August 2009

AbstractCellular interactions between leukocytes and the endothelium are critical events in vascular biology, such as atherosclerosis and acute coronary syndrome. When monocytes and endothelial cells are activated via direct cell‐cell interaction, both types of cells express several biologically active molecules such as adhesion molecules, cytokines, coagulation and fibrinolytic factors, metalloproteinases, and vasoactive substances. All of these molecules could contribute to atherogenesis and thrombosis.
Impact of chronic patency of infarct‐related coronary artery on prevalence of myocardial ischemia during the pharmacologic and exercise stress test
Authors: Lu Chunzeng , Marzilli Mario , Distante Alessandro , Wang Yanjun , De Nes Maurizio , Marraccini Paolo , L'Abbate Antonio 
Published: August 2009

AbstractBackground: Even late restoration of anterograde coronary flow may have beneficial effects on left ventricular function, electrophysiology, and survival in postinfarction patients.Hypothesis: The patency or occlusion of an infarct‐related coronary artery in the chronic phase may also be associated with myocardial ischemia provoked by pharmacologic and physiologic stress tests.Methods: High‐dose dipyridamole echocardiography test (DET) (up to 0.84 mg/kg over 10 min), exercise electrocardiography (EET), and coronary angiographic data in a group of 127 in‐hospital patients who had survived an acute myocardial infarction were analyzed. Patients who had only angiographic evidence of infarct‐related single artery disease (≥50% luminal diameter reduction) and no previous revascularization were enrolled in the study. DET and EET were performed (DET in all, EET in 118 patients) within 5 days before coronary angiography. Fifty‐seven patients had total occluded infarct arteries (Group 1) with various degrees of collateral circulation (2.6±1.1 collateral score, by a 3 grading system), whereas the other 70 patients had patent infarct arteries (Group 2) with significant residual stenoses (82±13% diameter reduction).Results: The prevalence of rest angina or effort angina and topography of the infarct‐related coronary artery did not differ between the two groups (all p = NS). There were more patients with Q wave in Group 1 than in Group 2 (72 vs. 57%, p = 0.08) compared with non‐Q wave infarction (Group 1 = 28 vs. Group 2 = 43%, p = 0.08). Ischemia in the infarct‐related artery territory detected by DET (defined as new wall motion dyssynergy or marked worsening of resting hypokinesia) was 61% in Group 1 and 41% in Group 2 (p = 0.025). EET was positive in 26 of 54 (48%) Group 1 and in 21 of 64 (33%) Group 2 patients (p = 0.09).Conclusions: Patients with occluded infarct‐related arteries have a higher prevalence of ischemia during DET and EET regardless of the presence of collateral flow. These results suggest that the presence of partial anterograde flow in the prolonged period could have a favorable influence on prevalence of residual ischemia in these patients.
Costs and outcomes of patients admitted with chest pain and essentially normal electrocardiograms
Authors: McCullough Peter A. , Ayad Osama , O'Neill William W. , Goldstein James A. 
Published: August 2009

AbstractBackground: Although inroads have been made in the outpatient evaluation of chest pain, the majority of hospitals in the United States do not have chest pain centers and the direct costs associated with hospital admissions in low‐risk patients is unknown.Hypothesis: The study was undertaken to evaluate the cost and outcomes of admission to the hospital for patients with acute chest pain and essentially normal electrocardiograms (ECGs).Methods: For that purpose, we reviewed 1,670 patients presenting to our emergency department with chest pain over a 5‐month period in 1994. Of these, 567 [34.0%, confidence interval (CI) 95%, 31.7–36.3%] patients were considered to be low risk by ECG criteria alone.Results: Complete clinical and financial data were available in 445 cases of which 152 had a previous history of coronary artery disease (CAD) and 31 (7.0%, CI95%, 4.9‐9.6%) were ultimately proven to have acute myocardial infarction (AMI). There were no deaths. All patients initially underwent noninvasive evaluation, and an additional 177 (39.8%) underwent subsequent cardiac catheterization. Of those, 107 (60.5%) had significant CAD (at least one vessel>70% stenosis). We assumed an expected mortality rate of 1% in the AMI group based on previously reported series with all the mortalities preventable by hospitalization. This yielded a valuation of $1.7 million dollars per life saved. Sensitivity analysis revealed the practice of admission and in‐patient evaluation for this group of patients was cost ineffective at all assumption levels.Conclusion: The practice of hospital admission for patients with chest pain and essentially normal ECGs is not cost favorable, and all hospital facilities should consider outpatient chest pain evaluation strategies.
Acute changes of left atrial distensibility in congestive heart failure
Authors: Dernellis John M. , Vyssoulis Gregory P. , Zacharoulis Apostolos A. , Toutouzas Pavlos K. 
Published: August 2009

AbstractBackground: Investigations of the left atrial (LA) distensibility have revealed that it plays a major role in atrial function; however, LA distensibility has not as yet been studied in congestive heart failure (CHF).Hypothesis: The study was undertaken to determine the effects of acute administration of esmolol, isosorbide dinitrate, dobutamine, and normal saline infusion on LA dimension, pressure, and distensibility.Methods: The study included 23 patients with CHF (18 with ischemic heart disease and 5 with idiopathic dilated cardiomypathy). Left atrial diameters (D) and pressures (P) were recorded at rest and thereafter during acute tests. P and D data during the ascending limb of the V loop were fitted to the exponential function P = b·ead, where a is the passive elastic chamber stiffness constant and b is the elastic constant. The instantaneous diastolic LA distensibility (IDLAD) was calculated as 1/(dP/dD)= 1/a·P.Results: The constant, a, increased significantly after normal saline and esmolol infusion (p<0.001), while it significantly decreased after isosorbide dinitrate (p <0.001) and dobutamine administration (p <0.05) compared with baseline. Instantaneous diastolic LA distensibility (in mm/Hg) was 0.16 at baseline; it significantly increased after isosorbide dinitrate (0.32) and dobutamine (0.24) administration, while it significantly decreased after normal saline (0.11) and esmolol (0.12) infusion (p <0.001 for all).Conclusion: In CHF, LA distensibility may acutely increase with vasodilators or inotropics or may decrease with beta blockade or volume loading.