bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of angiotensin‐converting enzyme inhibitors in patients with acute myocardial infarction in community hospitals
Authors: Dwamena Francesca C. , El‐Tamimi Hassan , Watson Ralph E. , Kroll Jill , Mclane Annette , Holmes‐Rovner Margaret , Mcintosh Barbara , Kupersmith Joel , Stein Aryeh D. 
Published: February 2009

AbstractBackground: Previous studies documenting underutilization of angiotensin‐converting enzyme inhibitors (ACEIs) in acute myocardial infarction (AMI) have been limited to Medicare populations.Hypothesis: This study examines ACEI prescription rates and predictors in a community sample of hospitalized patients with AMI.Methods: The charts of 1163 community patients with AMI, prospectively identified at admission between January 1, 1994, and April 30, 1995, were reviewed.Results: Only 64 of 158 (40%) patients considered ideal candidates for ACEI prescription were discharged with a prescription for an ACEI. In a multivariate logistic regression model, prior ACEI utilization [adjusted odds ration (OR) = 3.26; 95% confidence interval (CI) = 2.05–5.20], presence of congestive heart failure (OR = 2.33; CI = 1.50–3.61) and black race (OR = 2.20; CI = 1.34–3.64) were identified as positive predictors of ACEI prescription. Conversely, lack of left ventricular ejection fraction (LVEF) measurement (OR = 0.46; CI = 0.28–0.75), LVEF > 40 (OR = 0.27; CI = 0.18–0.40), and acute renal failure (OR = 0.08; CI = 0.01–0.44) were negative predictors. Women were also less likely to be discharged with an ACEI prescription (OR = 0.71; CI = 0.48–1.05). Furthermore, women were significantly less likely to have LVEF measured prior to discharge than were males (77 vs. 85%, p = 0.001).Conclusion: This study underscores the need for improvement in the utilization of ACEI in eligible patients with AMI. It also identifies opportunities for improvement in prescription rates, especially in women.
Exercise‐induced QTc‐interval changes for predicting improvement in regional blood flow in ischemic myocardium and cardiac output after coronary angioplasty in patients with right bundle‐branch block
Authors: Watanabe Takuya , Katagiri Takashi , Yamanaka Hideyuki , Akutsu Yasushi , Michihata Tetsuo , Okazaki Osamu , Harumi Kenichi 
Published: February 2009

AbstractBackground: We have previously shown that QT‐interval changes are more useful than ST‐T changes in evaluating the severity of exercise‐induced myocardial ischemia in patients with right bundle‐branch block (RBBB).Hypothesis: The purpose of this study was to evaluate whether the improvement in regional myocardial blood flow (RMBF) in ischemic areas and cardiac output after percutaneous transluminal coronary angioplasty (PTCA) can be predicted by exercise‐induced QT‐interval changes prior to PTCA.Methods: The RMBF and cardiac output were quantified with nitrogen‐13 ammonia positron emission tomography at rest and during exercise in 20 patients with RBBB and ischemic heart disease before and 6 months after PTCA, and in 9 healthy volunteers.Results: Before PTCA, exercise‐induced prolongation by <20 ms or shortening of the Bazett‐corrected QT (QTc) interval (454 ± 38 to 451 ± 41 ms, p = NS) was observed in 13 patients (Group 1) and prolongation by ≥20 ms (429 ± 44 to 466 ± 50 ms, p < 0.002) was observed in 7 (Group 2). The number of regions of exercise‐induced ischemia was significantly greater in Group 2 than in Group 1 (4.0 ± 1.2 vs. 2.1 ± 1.2, p < 0.01). The RMBF in regions of exercise‐induced ischemia and cardiac output at rest was not significantly different between Groups 1 and 2, whereas during exercise both the parameters were significantly lower in Group 2 than in Group 1 (both p < 0.05). After successful PTCA, RMBF both at rest and during exercise improved significantly in Group 1 (0.67 ± 0.04 to 0.71 ± 0.06 ml/min/g, 0.74 ± 0.05 to 0.84 ± 0.08 ml/min/g; both p < 0.0001), but did not improve significantly in Group 2 (0.63 ± 0.05 to 0.65 ± 0.07 ml/min/g, 0.65 ± 0.04 to 0.69 ± 0.11 ml/min/g; both p = NS). Cardiac output during exercise improved significantly in Group 1 (6.4 ± 0.7 to 7.4 ± 0.9 l/min; p<0.002) but not in Group 2 (5.7 ± 0.6 to 5.9 ± 0.6 l/min; p = NS).Conclusions: Our results suggest that the marked prolongation of the QTc interval induced by pre‐PTCA exercise may predict a lack of improvement in RMBF in ischemic areas and cardiac output after PTCA in patients with RBBB and ischemic heart disease.
Cardiac sympathetic activity in the asymmetrically hypertrophied septum in patients with hypertension or hypertrophic cardiomyopathy
Authors: Shimizu Masami , Ino Hidekazu , Okeie Kazuyasu , Emoto Yorito , Yamaguchi Masato , Yasuda Toshihiko , Fujino Noboru , Fujii Hiroyuki , Fujita Shinichiro , Mabuchi Hiroshi , Nakajima Kenichi , Taki Junichi 
Published: February 2009

AbstractBackground: In patients with essential hypertension (HT), proportional (symmetric) left ventricular hypertrophy (LVH) is common. In contrast, hypertrophic cardiomyopathy (HCM) is characterized by disproportional LVH and, in particular, asymmetric septal hypertrophy (ASH); however, some hypertensive patients also develop ASH. It has not been determined whether such cases represent a distinct type of hypertensive LVH or HCM combined with hypertension.Hypothesis: The study was undertaken to evaluate sympathetic activity in the interventricular septum in patients with HT and ASH or in patients with HCM.Methods: The patients were evaluated by I–123 metaiodobenzylguanidine (MIBG) and thallium‐201 (201Tl) single‐photon emission computed tomography (SPECT), respectively. They were divided into three groups: patients with essential HT and symmetric septal hypertrophy (Group A), patients with HT and ASH (Group B), and patients with HCM and ASH (Group C).Results: Compared with the lateral wall, early uptake of MIBG in the septum was significantly higher in Group B than in Group A, but not significantly different between Groups A and C. Compared with the lateral wall, early uptake of 201Tl in the septum did not differ among the three groups. No significant difference in the MIBG clearance in the lateral wall was seen among the three groups. By contrast, MIBG clearances in the septum and apex were significantly greater in Group C than in Groups A and B. There was an inverse correlation between systolic thickening and MIBG clearance in the septum.Conclusion: These findings suggest that sympathetic activity in the septum differs between patients with HT and ASH and patients with HCM.
Influence of autonomic neuropathy upon left ventricular dysfunction in insulin‐dependent diabetic patients
Authors: Monteagudo Patricia T. , Zanella M. Teresa , Moisés Valdir A. , Lima Valter C. , Kohlmann Osvaldo , Ribeiro Artur B. 
Published: February 2009

AbstractBackground: Diabetic cardiomyopathy is a well‐defined complication of diabetes that occurs in the absence of ischemic, vascular, and hypertensive disease.Hypothesis: The study was undertaken to test the relationship among autonomic neuropathy (AN), 24‐h blood pressure (BP) profile, and left ventricular function.Methods: Nineteen type‐1 diabetic patients underwent autonomic tests and echocardiographic examination. Patients were divided according to the presence (AN+) or absence (AN‐) of AN.Results: In the AN+ group (n = 8), the E/A ratio at echo was lower than in the AN– group (n = 11) (1.1 ± 0.3 vs. 1.6 ± 0.3; p < 0.005). Systolic and diastolic BP reductions during sleep were smaller in the AN+ than in the AN– group (6.6 ± 6.6 vs. 13.0 ± 4.3%; p < 0.03 for systolic and 12.8 ± 6.8 vs. 20.0 ± 4.0% for diastolic BP reduction; p < 0.03, respectively). Considering all patients, the E/A ratio correlated inversely with awake diastolic BP (r – 0.63; p = 0.005); sleep systolic BP (r – 0.48; p = 0.04), and sleep diastolic BP (r – 0.67; p = 0.002). The AN correlated with diastolic interventricular septum thickness (r 0.57; p = 0.01), sleep systolic BP (r 0.45; p = 0.05), sleep diastolic BP (r 0.54; p = 0.02), and correlated inversely with systolic and diastolic sleep BP reduction (r – 0.49; p = 0.03 and r – 0.67; p = 0.002, respectively). Finally, E/A ratio and AN score correlated between themselves (r – 0.6; p = 0.005).Conclusion: Our results suggest that left ventricular diastolic dysfunction may be detected very early in type‐1 diabetic patients with AN. Parasympathetic lesion and nocturnal elevations in BP could be the link between AN and diastolic ventricular dysfunction.
Effects of intravenous dofetilide in patients with frequent premature ventricular contractions: A clinical trial
Authors: Pool Peter E. , Singh Steven N. , Friedrich Tilman 
Published: February 2009

AbstractBackground: Although suppression of premature ventricular contractions (PVCs) is not a predictor of mortality over the long term, the extent of PVC suppression is an important characteristic of any antiarrhythmic drug.Hypothesis: This study was undertaken to determine whether intravenous (IV) dofetilide has the ability to suppress PVCs in patients who have frequent occurrences.Methods: Subjects were men and women, aged 18 to 75 years, with > 30 PVCs/h on two consecutive 24‐h Holter recordings while drug free, and > 50 PVCs/h during a 2‐hour telemetric electrocardiogram. The study was randomized, double‐blind, and placebo controlled. Subjects received a single‐blind, IV infusion of placebo and were randomized (3:1) to receive a double‐blind second infusion of placebo or an infusion of dofetilide (a 15‐min loading infusion of 4 g/kg followed by a 60‐min maintenance infusion of 3.5 g/kg, for a total dose of 7.5 g/kg).Results: Dofetilide produced an 82.6% and placebo a 2.9% median reduction in PVCs. Drug responder rate, defined as 80% reduction in PVCs, was 50% in the dofetilide group and 0% in the placebo group.Conclusion: Intravenous dofetilide significantly reduced PVCs in patients who had > 30 PVCs/h at baseline, and it produced ≥ 80% reduction in PVCs in 50% of all subjects.
Comparison of echocardiography and electron beam tomography in differentiating the etiology of heart failure
Authors: Le Thuy , Ko John Y. , Tina Kim H. , Akinwale Pamela , Budoff Matthew J. 
Published: February 2009

AbstractBackground: The clinical manifestations in patients with ischemic cardiomyopathy are often indistinguishable from those in patients with primary dilated cardiomyopathy (DCM). Clinicians often base work‐up of patients with heart failure on echocardiographic wall motion abnormalities; however misclassification can lead to unnecessary coronary angiography.Hypothesis: The study was undertaken to evaluate the diagnostic ability of echocardiography and electron beam tomography (EBT) to differentiate between ischemic and nonischemic cardiomyopathy.Methods: The accuracy of EBT and echocardiography was compared in 111 patients undergoing coronary angiography for the evaluation of heart failure. The presence of coronary calcification (CC) by EBT or segmental wall motion abnormalities by echocardiography was used as evidence of coronary‐induced cardiomyopathy.Results: Of 63 patients, 61 (97%) with obstructive coronary artery disease had CC by EBT. This sensitivity was significantly higher compared with 43 of 63 patients (68%) with segmental wall motion abnormalities by echocardiography (p < 0.001). Of 48 patients without obstructive coronary artery disease by angiography, 39 (81%) had no CC by EBT and 35 (73%) had no segmental wall motion (global hypokinesis) by echocardiography (p = 0.33). The overall accuracy of EBT to differentiate ischemic from nonischemic cardiomyopathy was 90%, significantly higher than echocardiography (70%, p < 0.001).Conclusion: This double‐blind study demonstrates that the presence of CC by EBT is superior to that of segmental wall motion abnormalities by echocardiography to distinguish ischemic from nonischemic cardiomyopathy. This modality may prove to be an important diagnostic tool when the etiology of the cardiomyopathy is not clinically evident.
Is ventricular repolarization heterogeneity a cause of serious ventricular tachyarrhythmias in aortic valve stenosis?
Authors: Batur M. K. , Açil T. , Önalan O. , Yildirir A. , Övünç K. , Kabakci G. , Oto A. , Özkutlu H. , Nazli N. , Gürsel G. , Kes S. 
Published: February 2009

AbstractBackground: It is well known that there is a close relation between sudden cardiac death and serious ventricular tachyarrhythmias in patients with aortic valve stenosis (AS). QT dispersion (QTd) reflects the ventricular repolarization heterogeneity and has been proposed as an indicator for ventricular arrhythmias.Hypothesis: This study investigated the QTd and its relevance to the clinical and echocardiographic variables.Methods: In all, 51 patients (33 men, 18 women, mean age 56±12) with isolated AS and 51 age‐ and gender‐matched healthy controls comprised the study group. Left ventricular mass index (LVMI) was calculated by the Devereux formula, and we used continuous‐wave Doppler (n = 15) and cardiac catheterization (n = 36) for the determination of the maximum aortic valve pressure gradient (PG).Results: Corrected QTd (QTcd) (89±39 vs. 49±15 ms, p<0.001) and LVMI (176±69 g/m2 vs. 101±28 g/m2, p<0.001) in patients with AS were significantly different from those in the control group. The group of 21 patients had a significantly greater number of 24‐h mean ventricular premature beats (VPB) and mean number of couplet VT episodes than did the control group (p<0.05). QTcd also correlated significantly well with LVMI (r=0.58, p<0.001), PG (r=0.41, p=0.003), and number of 24‐h VPB (r=0.56, p=0.008). With respect to symptoms (e.g., angina, syncope, and dyspnea) patients without symptoms (n=19) displayed less QTcd (71±31 vs. 100±39 ms, p=0.007) and less LVMI (144±80 g/m2 vs. 195±57 g/m2, p=0.01) than patients with symptoms. Statistical analysis was similar for all variables with uncorrected QTd values.Conclusion: We found that ventricular repolarization heterogeneity was greater in patients with AS than in controls. Our findings also showed that QTd in the patient group correlates well with LVMI, severity of AS, and PG. The present results suggest that serious ventricular arrhythmias in patients with AS may be due to spatial ventricular repolarization abnormality.
The prediction of coronary atherosclerosis employing artificial neural networks
Authors: George Jacob , Levy Yair , Gilburd Boris , Shoenfeld Yehuda , Ahmed Alaa , Patnaik Madhumita , Terrybery Jeff , Shen Guo Qui , Peter James , Adler Yehuda , Sagie Alex , Herz Itzhak , Harats Dror , Snow Peter , Brandt Jeff 
Published: February 2009

AbstractBackground: Atherosclerosis is a complex histopathologic process that is analogous to chronic inflammatory conditions. Several factors have been shown to correlate with the extent of atherosclerosis. Whereas hypertension, obesity, hyperlipidemia, diabetes, smoking, and family history are all well documented, recent literature points to additional associated factors. Thus, antibodies to oxidized low‐density lipoprotein (oxLDL), cytomegalovirus (CMV), Chlamydia pneumonia, Helicobacter pylori, as well as homocysteine and C‐reactive protein (CRP) levels have all been implicated as independent markers of accelerated atherosclerosis.Hypothesis: In the current study we attempted to formulate a system by which to predict the extent of coronary atherosclerosis as assessed by angiographic vessel occlusion.Methods: The 81 patients were categorized as having single‐, double‐, triple‐, or no vessel involvement. The clinical data concerning the “classic” risk factors were obtained from clinical records, and sera were drawn from the patients for determination of the various parameters that are thought to be associated with atherosclerosis.Results: Using four artificial neural networks, we have found the most effective parameters predictive of coronary vessel involvement were (in decreasing order of importance) antibodies to oxLDL, to cardiolipin, to CMV, to Chlamydia pneumonia, and to β2‐glycoprotein I (β2GPI). Although important in the prediction of vessel occlusion, hyperlipidemia, hypertension, CRP levels, and diabetes were less accurate.Conclusion: The results of the current study, if reproduced in a larger population, may establish an integrated system based on the creation of artificial neural networks by which to predict the extent of atherosclerosis in a given subject fairly and noninvasively.
The effect of transient balloon occlusion of the mitral valve on left atrial appendage blood flow velocity and spontaneous echo contrast
Authors: Wang Jianan , Choo Daniel Chung Ann , Zhang Xianglan , Yang Qian , Xian Tangchao , Lu Duan , Jiang Shan 
Published: February 2009

AbstractBackground: Spontaneous echo contrast (SEC) is a phenomenon that is commonly seen in areas of blood stasis. It is a slowly moving, cloud‐like swirling pattern of “smoke” or increased echogenicity recorded on echocardiography. SEC is commonly seen in the left atrium of patients with mitral stenosis or atrial fibrillation. The prescence of SEC has been shown to be a marker of increased thromboembolic risk.Hypothesis: By using transesophageal echocardiography during percutaneous balloon mitral valvotomy (PBMV), the study investigated the relationship between SEC and varying left atrial appendage (LAA) blood flow velocity in the human heart.Methods: Thirty—five patients with rheumatic mitral stenosis underwent percutaneous balloon mitral valvotomy with intraoperative transesophageal echocardiography monitoring. We alternatively measured LAA velocities and observed the left atrium for various grades of SEC (0 = none to 4 = severe) before and after each balloon inflation.Results: Left atrial appendage maximal ejection velocity was reduced from 35 ± 14 to 6 ± 2 mm/s at peak balloon inflation and increased to 40 ± 16 mm/s after balloon deflation. In comparison with the values before balloon inflation and after balloon deflation, LAA velocities were significantly lower (p < 0.001). New or increased SEC grade was observed during 54 of 61 (88%) inflations and unchanged in 7 (12%) inflations at peak balloon inflation. Spontaneous echo contrast became lower in grade after 55 balloon deflations (90%), completely disappeared after 18 deflations (30%), and remained unchanged after 6 deflations (10%). The mean time to achieve maximal SEC grade (2.5 ± 1.2 s) coincided with the mean time to trough LAA velocities (2.3 ±1.1 s) after balloon inflation. Upon deflation, the mean time to lowest SEC grade (2.9 ± 1.8 s) coincided with mean time to achieve maximal LAA velocities (2.7 ± 1.6s).Conclusion: During balloon inflation, the severity of SEC was enhanced with corresponding reduction in LAA flow velocity. Upon balloon deflation, SEC lightens or disappears with increase in LAA flow velocity.
Relation of transesophageal echocardiographic findings to subtypes of cerebral infarction in patients with atrial fibrillation
Authors: Shinokawa Noriko , Hirai Tadakazu , Takashima Shutaro , Kameyama Tomoki , Obata Yoshiko , Nakagawa Keiko , Asanoi Hidetsugu , Inoue Hiroshi 
Published: February 2009

AbstractBackground: Transesophageal echocardiography (TEE) has been used to identify the potential risk for cardiogenic embolism in patients with atrial fibrillation (AF). However, ischemic stroke in patients with AF is not always attributable to embolism. Identification of the risk of embolic versus athero‐thrombotic stroke should lead to the optimal individualized management of patients with AF.Hypothesis: The goal of the study was to determine the relation between cortical infarction and perforating infarction and TEE findings in patients with AF.Methods: We investigated the clinical usefulness of TEE in the risk stratification of clinical subtyping of the cerebral infarctions which were divided into two territories of the cortical branch (cortical infarction due to embolism) and deep perforators (perforating infarction due to atherothrombosis). Left atrial spontaneous echo contrast, peak flow velocity in the left atrial appendage, and generalized atherosclerosis as estimated by the intima‐media wall thickness of the thoracic aorta were assessed by TEE in 118 consecutive patients with either paroxysmal (n = 44) or chronic (n = 74) AF. All patients underwent either brain computed tomography or magnetic resonance imaging.Results: Cortical and perforating infarction was found in 39 and 18% of patients, respectively. The grade of spontaneous echo contrast was higher in patients with than in those without cortical infarction (p<0.05). In contrast, patients with perforating infarction showed significant increase in the aortic wall thickness when compared with patients without perforating infarction (p <0.05). In addition, multivariate logistic analysis revealed that spontaneous echo contrast was an independent predictor of cortical infarction, while intima‐media wall thickness of the aorta, hypertension, and age were useful in predicting the risk of perforating infarction.Conclusions: Transesophageal echocardiography has a potential role in the risk stratification for cortical and perforating infarction in patients with AF.
Failure of magnesium to protect isolated cardiomyocytes from effects of hypoxia or metabolic poisoning
Authors: Gallagher Mark M. , Allshire Ashley P. 
Published: February 2009

AbstractBackground: MgSO 4 appears to reduce infarct size in animal models of myocardial infarction‐reperfusion, but only if given before reperfusion. The mechanisms underlying this effect have not been established, nor has the discrepancy between these results and the lack of efficacy in the Fourth International Study of Infarct Survival (ISIS‐4) been explained.Hypothesis: The study was undertaken to examine the hypothesis that Mg 2+ protects myocardium threatened by ischemia.Methods: We studied the effects of extracellular magnesium [Mg2+ ] e at 0.6 and 1.8 mmol/l on isolated myocytes exposed to 2.5 mmol/l NaCN + 5 mmol/l 2‐deoxyglucose or to profound hypoxia.Results: Nonpaced cells shortened at a mean of 8.8 min after onset of metabolic inhibition in [Mg 2+] e =1.8 mmol/l, 9.6 min in [Mg 2+]s e = 0.6 mmol/l (not significant). Paced cells shortened after 9.5 min in [Mg 2+] e = 1.8 mmol/l, 10.2 min at [Mg 2+ ] e = 0.6 mmol/l. On washout of inhibitors, 93% of cells underwent hypercontracture at [Mg 2+ ] e = 1.8 mmol/l, 94.8% at [Mg 2+ ] e = 0.6 mmol/l. During hypoxia, nonpaced cells in [Mg 2+ ] e = 1.8 mmol/l shortened after 67 ± 11 min compared with 62.5 ± 28 min at [Mg 2+ ] e = 0.6 mmol/l. Paced cells shortened after 25.8 ± 12.9 min at [Mg 2+] e = 1.8 mmol/l and after 28.7 ± 13.6 min at [Mg 2+ ] e = 0.6 mmol/l. Although there was a trend toward longer survival at higher [Mg 2+ ] e, the difference was small and not significant (p > 0.05, Student's paired t‐test).Conclusion: We find no evidence to support the hypothesis that [Mg 2+ ] protects myocardium threatened by ischemia.This is consistent with clinical data but contradicts data from animal experiments.
Cox‐maze procedure for treatment of atrial flutter associated with an atrial septal defect
Authors: Dakik Habib A. , Arnaout Samir , Khoury Maurice , Obeid Mounir 
Published: February 2009

AbstractA 52‐year‐old man presented with atrial flutter and was found to have an atrial septal defect (ASD). The paper describes an effective surgical approach for the treatment of this atrial arrhythmia utilizing a right sided Cox‐maze EI procedure concomitant with ASD closure. Review of the literature and clinical implications are discussed.