bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in QT dispersion during adenosine infusion
Authors: Kumar Ananth , Narasimhan Calambur , Sankari Abdul , Ranginani Anil , Lennon Catherine , Bekerman Carlos , Clark William , Denes Pablo 
Published: February 2009

AbstractBackground: QT dispersion (QTd) measurement during treadmill stress testing has been to shown to improve the accuracy of exercise electrocardiogram (ECG) in the detection of significant coronary artery disease (CAD).Hypothesis: The aim of this study was to determine whether adenosine‐induced changes in QTd could predict significant CAD and to assess its efficacy as a diagnostic index in patients undergoing adenosine stress test.Methods: QT interval measurements were made in 57 consecutive patients undergoing adenosine sestamibi stress test. Patients with an abnormal stress test underwent coronary angiography. Patients with significant disease by coronary angiography (> 70% stenosis) were classified as having CAD (Group 1), and those with normal stress images and/or normal coronaries by angiography were classified as having no CAD (Group 2).Results: QT dispersion increased from 28.2 ± 4.5 to 43.8 ± 4.5 ms with a ΔQTd of 15.53 ± 3.68 in Group 1 (p = 0.001) and from 28.4 ± 2.6 to 34.8 ± 2.8 ms with a ΔQTd of 6.58 ± 2.21 ms in Group 2 (p = 0.006). Patients in Group 1 had a significantly higher increase in QTd (ΔQTd) than the patients in Group 2 (p < 0.03). Addition of ΔQTd (> 10 ms) to the ST depression during adenosine infusion would increase the sensitivity of the ECG from 23 to 65% and decrease the specificity from 91 to 70% for diagnosis of significant CAD.Conclusions: ΔQTd is significantly more prolonged in patients with CAD during adenosine infusion. It increases the sensitivity of the stress ECG in diagnosis of CAD during adenosine infusion when used as an adjuvant index.
Monotherapy with amlodipine or atenolol versus their combination in stable angina pectoris
Authors: Kenneth Pehrsson S. , Ringqvist Ivar , Ekdahl Sten , Karlson BjÖRn W. , Ulvenstam GÖRan , Persson Stig 
Published: February 2009

AbstractBackground: The basic cause of angina pectoris is imbalance between the metabolic needs of the myocardium and the capacity of the coronary circulation to deliver sufficient oxygenated blood to satisfy these needs.Hypothesis: The study was undertaken to evaluate whether the effect of combined amlodipine and atenolol therapy on patients with stable angina pectoris and with ST‐depression during exercise testing and 48‐h ambulatory electrocardiographic monitoring is superior to that of either agent given alone.Methods: Patients with stable angina pectoris and ST depression during exercise and ambulatory monitoring were randomized to receive amlodipine (n = 116) or atenolol (n = 116), or both (n = 119). All patients were also treated with short‐ and long‐acting nitrates. The design was a double‐blind, randomized, triple‐arm parallel group study with 10 weeks of administration of the test medication.Results: In terms of time to onset of ST depression > 1 mm, time to onset of angina, total exercise time, maximum achieved workload, and peak intensity of angina, amlodipine and atenolol alone were as effective as their combination. During ambulatory monitoring, atenolol was more effective than amlodipine regarding total time and number of ST‐depression episodes, and as effective as the combined drugs.Conclusion: For individual patients with stable angina pectoris, combination of a beta blocker with a calcium antagonist is not necessarily more effective than either drug given alone.
Endothelial function and peripheral vasomotion in the brachial artery in neurally mediated syncope
Authors: Takase Bonpei , Akima Takashi , Uehata Akimi , Katushika Syuichi , Isojima Kazusige , Satomura Kimio , Ohsuzu Fumitaka , Kurita Akira 
Published: February 2009

AbstractBackground: Paradoxical peripheral vasodilation is one of the suspected mechanisms of neurally mediated syncope. Parasympathetic stimulation following sympathetic activation during orthostatic stress mainly contributes to this vasodilation.Hypothesis: Since endothelial function modulates peripheral vascular tone, this study aimed to determine whether endothelial function and inappropriate peripheral vasomotion has a significant role in the pathogenesis of neurally mediated syncope.Methods: To investigate whether endothelial function is augmented or whether abnormal peripheral vasomotion exits, flow‐mediated dilation (FMD, endothelium‐dependent vasodilation) and sublingual glyceryl trinitrate‐induced dilation (0.3 mg, GTN‐D, endothelium‐independent vasodilation) were measured in the brachial artery in 16 patients with neurally mediated syncope, aged 33 ± 10 years, by using high‐resolution ultrasound. All patients underwent positive head‐up tilt testing. These measures were compared with those in 16 control subjects matched with the patients by age, gender, and coronary risk factors. For FMD, percent diameter changes were obtained from baseline to hyperemic conditions (1 min after 5 min occlusion of the forearm artery). There were five smokers in both the patient and the control groups, but there was no structural heart disease in either group.Results: Baseline brachial artery diameters were comparable (3.8 ± 0.6 vs. 3.8 ± 0.7 mm, NS). Flow‐mediated dilation in patients with neurally mediated syncope had a normal value of 9.8 ± 5.0% despite the inclusion of five smokers. Flow‐mediated dilation and GTN‐D in patients with neurally mediated syncope were significantly greater than those in controls (9.0 ± 5.0 vs. 3.0 ± 3.5%, p<0.05; 18.4 ± 5.5 vs. 14.1 ± 4.4%, p<0.05).Conclusions: Augmented endothelial function and/or abnormal peripheral vasomotion in peripheral arteries are important in patients with neurally mediated syncope in selected populations.
Chagas' Heart Disease
Authors: Jr Anis Rassi , Rassi Anis , Little William C. 
Published: February 2009

AbstractChagas' disease is caused by a protozoan parasite, Trypanosoma cruzi, that is transmitted to humans through the feces of infected bloodsucking insects in endemic areas of Latin America, or occasionally by nonvectorial mechanisms, such as blood transfusion. Cardiac involvement, which typically appears decades after the initial infection, may result in cardiac arrhythmias, ventricular aneurysm, congestive heart failure, thromboembolism, and sudden cardiac death. Between 16 and 18 million persons are infected in Latin America. The migration of infected Latin Americans to the United States or other countries where the disease is uncommon poses two problems: the misdiagnosis or undiagnosis of Chagas' heart disease in these immigrants and the possibility of transmission of Chagas' disease through blood transfusions. Diagnosis is based on positive serologic tests and the clinical features. The antiparasitic drug, benznidazole, is effective when given for the initial infection and may also be beneficial for the chronic phase. The use of amiodarone, angiotensin‐converting enzyme inhibitors, and pacemaker implantation may contribute to a better survival in selected patients with cardiac involvement of chronic Chagas' disease.
Restenosis and Progression of Coronary Disease after Balloon Angioplasty in Patients with Diabetes Mellitus
Authors: Rozenman Yoseph , Sapoznikov Dan , Gotsman Mervyn S. 
Published: February 2009

AbstractBackground: Patients with diabetes mellitus (D) (both insulin‐requiring D [IRD] and non‐IRD) who undergo angioplasty have worse long‐term outcome than do non‐D patients. Few data are available in the literature that explain these findings.Hypothesis: The study was undertaken to compare restenosis and progression of coronary disease after angioplasty in IRD patients, in non‐IRD patients, and in non‐D patients.Methods: Diabetic patients who underwent coronary angioplasty were separated into two subgroups: IRD and non‐IRD patients. Their angiographic outcome was compared with non‐D patients. We examined retrospectively 353 coronary angiograms of patients who were referred for diagnostic angiography > 1 month after successful angioplasty. Quantitative angiography was used to determine the outcome in dilated narrowings (restenosis) and in nondilated narrowings (disease progression).Results: Baseline clinical and angiographic characteristics were similar in all groups. Restenosis rate was higher in IRD (61 %) than in non‐IRD (36%) and non‐D (35%) patients (p = 0.04). Late luminal loss after angioplasty was two times greater in IRD patients than in the other two groups (p=0.01). Disease progression of nondilated narrowings was significantly more prominent in non‐IRD than in non‐D patients: Diameter stenoses were similar in the initial angiogram, but narrowings were significantly more severe (p=0.02) in the final angiogram (70 ± 27% and 60 ± 33%, respectively). New narrowings were more common in non‐IRD than in non‐D patients: there was a 23% increase in the number of narrowings in the follow‐up angiogram in non‐IRD patients compared with only 12% in non‐D patients (p < 0.003). These new narrowings were more common (p=0.01) in angioplasty arteries (57 narrowings on 420 arteries—13.6%) than in nonangioplasty arteries (54 narrowings on 639 arteries—8.5%).Conclusion: Restenosis is more common in IRD patients and explains the high rate of adverse cardiac events within the first year after coronary intervention in these patients (mainly target lesion revascularization). Disease progression (including new narrowings) is the main determinant of patient outcome > 1 year after coronary intervention and is accelerated in non‐IRD compared with non‐D patients.
Myocardial viability in patients with thrombolyzed myocardial infarction: Is it assessable by predischarge exercise electrocardiography test?
Authors: Samad Bassem A. , Hulting Johan , Ruiz Hernan , Höjer Jonas , Jensen‐Urstad Mats , Jensen‐Urstad Kerstin , Bouvier Fredric 
Published: February 2009

AbstractBackground: Most studies concerning exercise electrocardiography (ECG) testing after acute myocardial infarction (AMI) were carried out in the prethrombolytic era. ST‐segment elevation in the infarction area during exercise has usually been interpreted as indicating the presence of dyskinesia as a result of extensive left ventricle damage.Hypothesis: This study was undertaken to evaluate the contributions of exercise‐induced ST‐segment elevation and T‐wave pseudonormalization to the assessment of myocardial viability in patients with thrombolyzed myocardial infarction (MI), compared with low‐dose dobutamine echocardiography.Methods: The study comprised 52 consecutive patients with AMI treated with thrombolysis. All patients underwent low‐dose dobutamine echocardiography and symptom‐limited exercise testing before discharge.Nineteen patients showed ST‐segment elevation (Group 1), 9 showed isolated T‐wave pseudonormalization (Group 2), and 24 patients did not exhibit either of these ST‐T segment changes (Group 3). Low‐dose dobutamine echocardiography revealed evidence of viability in 16 patients (84%) in Group 1 (p=0.01), 5 (56%) in Group 2 (p=NS), and 11 patients (46%) in Group 3 (p = NS).Conclusion: Exercise‐induced ST‐segment elevation may contribute to the evaluation of myocardial viability in patients with AMI treated with thrombolysis. However, in the absence of exercise‐induced ST‐segment elevation, further noninvasive studies might be indicated to assess myocardial viability.
Influence of age on left atrial appendage function in patients with nonvalvular atrial fibrillation
Authors: Ilercil Arzu , Kondapaneni Jyothi , Hla Aung , Shirani Jamshid 
Published: February 2009

AbstractBackground: Age is an independent risk factor for thromboembolism in nonvalvular atrial fibrillation (NVAF). An association between low left atrial appendage (LAA) Doppler velocities and thromboembolic risk in NVAF has been reported.Methods: Forty‐two consecutive patients (age 69 ± 2 years [range 42–92], 24 [57%] men) with NVAF underwent transthoracic and transesophageal echocardiography. The following were compared in 22 patients younger and 20 older than 70 years: left ventricular (LV) diameter, mass and ejection fraction, left atrial (LA) diameter and volume, LAA area and volume, LAA peak emptying (PE) and peak filling (PF) velocities, presence and severity of spontaneous echo contrast (SEC) and mitral regurgitation (MR).Results: Left atrial diameter (4.6 ± 0.1 vs. 4.5 ± 0.2 cm), LA volume (105 ± 10 vs. 92 ± 8 ml), LAA area (6.8 ± 0.6 vs. 5.2 ± 0.8 cm), and LAA volume (5.6 ± 0.9 vs. 3.9 ± 1.0 ml) were similar (p>0.05) in both groups. Older patients had lower LAA PE (26 ± 2 vs. 34 ± 3 cm/s, p = 0.02) and PF (32 ± 2 vs. 41 ± 4 cm/s, p = 0.04) velocities, lower LV mass (175 ± 13 vs. 234 ± 21 gm, p = 0.02), higher relative wall thickness (0.52 ± 0.02 vs. 0.43 ± 0.03, p = 0.02), smaller LV diastolic diameter (4.3 ± 0.1 vs. 5.2 ± 0.2 cm, p <0.001), and higher LV ejection fraction (62 ± 2 vs. 55 ± 2%, p = 0.025). Frequency and severity of SEC and MR were similar in both groups. Multivariate analysis identified older age as the only significant predictor of reduced LAA velocities.Conclusion: Compared with younger patients, older patients with NVAF have lower LAA velocities despite higher LV ejection fraction, smaller LV size, and similar LA and LAA volumes. These findings may explain the higher thromboembolic rates in older patients with NVAF.
Combination treatment with telmisartan and hydrochlorothiazide in black patients with mild to moderate hypertension
Authors: Mcgill Janet B. , Reilly Paul A. 
Published: February 2009

AbstractBackground: Hydrochlorothiazide (HCTZ) is commonly used to treat black patients with hypertension. To avoid the metabolic disturbances associated with high‐dose HCTZ, blood pressure control may be achieved by combining low doses with another antihypertensive.Hypothesis: The study was undertaken to assess the tolerability and antihypertensive dose‐response efficacy of telmisartan and HCTZ and their combination in black patients with mild to moderate hypertension (mean supine blood pressure 140/95‐200/114 mmHg).Methods: Following a 4–week, single‐blind, placebo run‐in period, 222 black patients were randomized to once‐daily treatment with one of 20 different double‐blind combinations of telmisartan (0, 20, 40, 80, 160 mg) and HCTZ (0, 6.25, 12.5, 25 mg) for 8 weeks. Blood pressure was measured at baseline and after 2, 4, and 8 weeks.Results: Telmisartan 80 mg/HCTZ 12.5 mg reduced supine trough diastolic blood pressure (DBP)—primary efficacy parameter—by 13.3 mmHg, and supine trough systolic blood pressure (SBP) by 21.5 mmHg. These reductions represented benefits of 13.7/8.7 mmHg over telmisartan 80 mg and 12.3/8.1 mmHg over HCTZ 12.5 mg(p<0.01). Telmisartan 40 mg/HCTZ 12.5 mg reduced supine trough SBP/DBP by 14.3/10.0 mmHg, amounting to 12.3/3.3 mmHg more than telmisartan 40 mg and 5.1/4.8 mmHg more than HCTZ 12.5 mg, This reached significance for the comparisons with telmisartan 40 mg for SBP and HCTZ 12.5 mg for DBP (p≤0.05). A response surface analysis and therapeutic response rates confirmed the additive antihypertensive effects of telmisartan and HCTZ. All treatments were well tolerated, with side‐effect profiles comparable with placebo. Adverse events were mainly transient and of mild to moderate severity.Conclusions: Telmisartan 80 mg combined with HCTZ 12.5 mg is effective and well tolerated in black patients with mild to moderate hypertension, providing greater antihypertensive activity than the corresponding monotherapies.
Homocysteine: A new cardiac risk factor?
Authors: Chai Andrew U. , Abrams Jonathan 
Published: February 2009

AbstractElevated plasma homocysteine levels have recently been implicated as a new risk factor for coronary artery disease. In this Article, homocysteine metabolism, secondary causes of elevated plasma homocysteine, and the potential mechanism of vascular damage in hyperhomocysteinemia are briefly reviewed. The current clinical evidence implicating hyperhomocysteinemia as a risk factor for coronary artery disease, as well as the data regarding the effects of B vitamin supplementation on homocysteine concentrations, are also reviewed. The current recommendation of the authors is to treat patients with known coronary artery disease or those who are considered to be at high risk for coronary artery disease with 400 μg of folate supplementation. Until prospective clinical trial data become available, this approach appears to be a safe and effective way to approach this patient population.
Single left coronary artery with origin of the right coronary artery from distal circumflex
Authors: Shammas Ronny L. , Miller Michael J. , Babb Joseph D. 
Published: February 2009

AbstractWe report two very unusual cases of agenesis of the right coronary ostium with continuation of the left circumflex artery as the right coronary artery. The recognition of the anomaly in the first case lead to a better understanding of this finding in the second case, which translated into shorter procedure time, less contrast volume, and fewer catheter manipulations.
Angiotensin receptor blockers: Evidence for preserving target organs
Authors: Carson Peter , Giles Thomas , Higginbotham Michael , Hollenberg Norman , Kannel William , Siragy Helmy M. 
Published: February 2009

AbstractHypertension is a major problem throughout the developed world. Although current antihypertensive treatment regimens reduce morbidity and mortality, patients are often noncompliant, and medications may not completely normalize blood pressure. As a result, current therapy frequently does not prevent or reverse the cardiovascular remodeling that often occurs when blood pressure is chronically elevated. Blockade of the renin‐angiotensin system (RAS) is effective in controlling hypertension and treating congestive heart failure. Both angiotensin‐converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) inhibit the activity of the RAS, but these two classes of antihypertensive medications have different mechanisms of action and different pharmacologic profiles. Angiotensin‐converting enzyme inhibitors block a single pathway in the production of angiotensin II (Ang II). In addition, angiotensin I is not the only substrate for ACE. The ACE inhibitors also block the degradation of bradykinin that may have potential benefits in cardiovascular disease. Bradykinin is, however, the presumed cause of cough associated with ACE inhibitor therapy. Data from clinical trials on ACE inhibitors serve to support the involvement of the RAS in the development of cardiovascular disease. Angiotensin receptor blockers act distally in the RAS to block the Ang II type 1 (AT1) receptor selectively. Thus, ARBs are more specific agents and avoid many side effects. Experimental and clinical trials have documented the efficacy of ARBs in preserving target‐organ function and reversing cardiovascular remodeling. In some instances, maximal benefit may be obtained with Ang II blockade using both ARBs and ACE inhibitors. This review describes clinical trials that document the efficacy of ARBs in protecting the myocardium, blood vessels, and renal vasculature.
Clinical characteristics of patients with increased urinary excretion of adrenaline in mild to moderate heart failure
Authors: Grochowicz Urszula , Wolk Robert , Bednarz Bronislaw , Budaj Andrzej , Ceremuzynski Leszek 
Published: February 2009

AbstractBackground: We have previously demonstrated that adrenaline (AD) is released into the circulation during acute myocardial infarction and is associated with a more severe clinical course. The role of elevated AD levels in congestive heart failure is not known.Hypothesis: The study aimed to determine whether increased daily AD excretion is associated with more severe clinical symptoms and a more complicated clinical course in patients with exacerbation of congestive heart failure (CHF).Methods: Urinary excretion of AD, noradrenaline, magnesium (Mg), and potassium (K), serum levels of aldosterone, K, and Mg, as well as the incidence of arrhythmias (24‐h Holter) were assessed in 49 patients with CHF New York Heart Association (NYHA) class II‐III. The patients were allocated to two groups, with normal (Group 1) and increased (Group 2) excretion of AD.Results: Groups 1 and 2 did not differ in respect of age, etiology of CHF, or the medication used. Also, left ventricular ejection fraction was similar in the two groups. However, left ventricular end‐diastolic dimension was greater in Group 2 (61 ± 9 vs. 55 ± 11 mm, p < 0.05), as was the proportion of patients in NYHA class III (74 vs. 40%). Group 2 was also characterized by increased urinary excretion of Mg (60 ± 24 vs. 43 ± 16 mg/24 h, p < 0.007) and the presence of more complex and numerous ventricular arrhythmias (74 vs. 37% and 68 vs. 33% of patients, respectively).Conclusions: Urinary excretion of AD is increased only in a subgroup of patients with CHF. These patients are characterized by a more advanced NYHA class, increased end‐diastolic left ventricular diameter, and increased urinary excretion of magnesium. It is likely that all these factors contribute to the presence of more complex and numerous ventricular arrhythmias in this subgroup of patients.
factors predicting success rate and recurrence of atrial fibrillation after first electrical cardioversion in patients with persistent atrial fibrillation
Authors: Frick Mats , Frykman Viveka , Jensen‐Urstad Mats , Östergren Jan 
Published: February 2009

AbstractBackground: The recurrence rate of atrial fibrillation (AF) after elective cardioversion is high.Hypothesis: The study aimed to identify clinical predictors for successful electrical cardioversion and maintenance of sinus rhythm after a first electrical cardioversion in patients with persistent AF without concomitant antiarrhythmic drugs of class I and III.Methods: Consecutive outpatients (n = 166) with persistent AF for > 1 month, scheduled for elective cardioversion, were prospectively included in the study. A clinical investigation, echocardiographic assay, and Holter electrocardiogram (ECG) before and ECG 4 weeks after cardioversion, were performed in all patients.Results: The mean age of the patients was 68 years (range 45–83) and duration of AF was 5 (1–48) months. Sinus rhythm was established in 124 (75%) patients. In multivariate analysis, only duration of AF < 6 months (p < 0.04, odds ratio [OR] 2.2, 95% confidence interval [CI] 1.1 to 4.7) and patients weight (p < 0.03, OR 2.3, 95% CI 1.1 to 4.8 for weight < 80 kg) were identified as independent predictors of successful cardioversion. At 4 weeks after cardioversion, only 46 (37%) of 124 patients maintained sinus rhythm. Independent factors for maintenance of sinus rhythm, in multivariate analysis, were AF < 3 months (p < 0.04, OR 2.5, 95% CI 1.1 to 5.6), treatment with beta blockers (p < 0.00001, OR 7.0, 95% CI 3.0 to 16.3) or verapamil/diltiazem (p < 0.04, OR 3.6, 95% CI 1.0 to 12.1), and right atrial dimension < 37 mm (p < 0.02, OR 5.9, 95% CI 1.4 to 25.4).Conclusions: In patients with persistent AF, the patient's weight and the duration of AF are independent predictors for a successful cardioversion. Short duration of AF, treatment with beta blockers or verapamil/diltiazem, and right atrial area/dimension are independent predictors for maintenance of sinus rhythm.