bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coronary flow velocity reserve in hypertensive patients with left ventricular systolic dysfunction
Authors: Pereira Valéria Fontenelle Angelim , De Carvalho Frimm Clovis , Rodrigues Ana Clara Tude , Tsutsui Jeane Mike , Cúri Mariana , Mady Charles , Ramires José Antonio Franchini 
Published: June 2007

AbstractBackground: Hypertensive microvascular disease is speculated to be a limiting factor for the ability of left ventricular (LV) hypertrophy to maintain LV systolic function in systemic hypertension. The role of coronary reserve, which may be affected by microvascular disease, remains uncertain in the pathophysiology of hypertensive heart disease.Hypothesis: A progressive impairment of coronary flow velocity reserve (CFVR) according to the presence and severity of LV systolic dysfunction is anticipated to occur in hypertension.Methods: According to the absence or presence of LV dysfunction (LV fractional shortening ‐ FS% < 30), two groups of hypertensive patients were investigated: HP1 (n = 9, FS% = 36 ± 6) and HP2 (n = 13, FS% = 18 ± 6). Eight normal subjects (NL) served as controls (LVFS% = 35 ± 3). Doppler blood flow velocity was obtained from the left anterior descending coronary artery using transesophageal echocardiography before and during 6‐min continuous adenosine infusion (140 μg·kg‐1 ·min‐1 intravenous). The CFVR was calculated as the ratio of maximal to baseline peak diastolic flow velocities.Results: The comparison among NL, HP1, and HP2 groups showed statistically different (p < 0.05) mass index (101 ± 18, 172 ± 46, and 257 ± 54 g·m‐2), end‐systolic wall stress (76.9 ± 14.4, 78.4 ± 23.9, and 174.5 ± 43.0 103·dyn·cm‐2), and CFVR (3.5 ± 0.6, 3.2 ± 0.4, and 2.6 ± 0.8), respectively. The CFVR correlated significantly and directly with LVFS% (r = 0.40) and correlated inversely with both mass index (r = −0.54) and end‐systolic stress (r = −0.40). Conclusions: These results indicate that CFVR impairment is weakly related to LV dysfunction in hypertension.
Adaptive mechanisms of left ventricular diastolic function to the physiologic load of pregnancy
Authors: Moran Adrian M. , Colan Steven D. , Mauer Mary Beth , Geva Tal 
Published: June 2007

AbstractBackground: Pregnancy is associated with marked alteration in cardiovascular hemodynamics. Recent reports have characterized the effects on cardiac systolic function. Little has been written on the influences of loading conditions on Doppler measures of diastolic function during pregnancy.Hypothesis: Stage of pregnancy has an impact on Doppler indices of diastolic function independent of loading conditions, systolic function, and heart rate.Method: Thirty healthy women were prospectively evaluated by serial echocardiography and Doppler examinations at six time periods: 10‐12, 18‐20, 28‐30, 36‐38 weeks gestation, 2‐4 and 12‐14 weeks postpartum. The related effects on indices of diastolic function and its interaction with load, heart rate, mass, and systolic function were determined.Results: Compared with the nonpregnant state, early (E) velocity increased (0.7 ± 0.1‐0.9 ± 0.1 m/s, p = 0.0001), peaking at 18 weeks and returning to normal levels during late pregnancy. Atrial phase (A) velocity peaked at 18 weeks (0.48 ± 0.12‐0.60 ± 0.13 m/s, p = 0.0001), remaining high throughout the rest of pregnancy. Consequently, the E/A ratio fell significantly during late pregnancy, from 1.9 ± 0.4 to 1.4 ± 0.3 (p = 0.02). In addition, mean acceleration was significantly increased in early pregnancy with a peak at 18 weeks (7.4 ± 1.3 m/s2), returning to nonpregnant level at term (5.7 ± 1.4 m/s2, p = 0.0001). Generalized estimating equation using multivariate regression analysis demonstrated that rising heart rate and stroke volume index had an independent effect on A velocity, and that contractility and preload had an independent effect on E velocity. Pregnancy itself had an independent influence on early filling, not explained by the other parameters.Conclusions: During normal pregnancy, there is a reversible shift in transmitral flow velocities from early to late filling with a decrease in acceleration, consistent with an increase in ventricular compliance. Changes in heart rate, preload, and contractility, as well as stage of pregnancy influence this alteration.
Shear‐induced platelet aggregation increases in patients with proximal and severe coronary artery stenosis
Authors: Kawano Koichi , Yoshino Hideaki , Aoki Nobuo , Udagawa Hiroshi , Watanuki Atsushi , Hioki Yoshiko , Hasumura Yukihisa , Yasumura Toshikaki , Homori Masashi , Murata Mitsuru , Ikeda Yasuo , Ishikawa Kyozo 
Published: June 2007

AbstractBackground: Shear stress generated in stenosed arteries promotes platelet thrombi formation at the stenosed sites by accelerating the binding of von Willebrand factor (vWF) to platelets. Shear‐induced platelet aggregation (SIPA) has been studied in acute coronary syndromes, but not in chronic coronary disease.Hypothesis: We investigated the effect of both the site and severity of coronary stenosis on SIPAin patients with chronic coronary artery disease.Methods: Shear‐induced platelet aggregation was measured using platelet‐rich plasma in 49 patients (41 men and 8 women; mean age 61 ± 10 years) with coronary artery disease to evaluate the association between the extent of SIPA and coronary angiographic findings. Stenoses > 75% were considered severe. In all, 62 healthy individuals (54 men and 18 women; mean age 45 ± 7 years) served as controls. The correlation between SIPA and the site and severity of the coronary lesion, and parameters of coagulation and fibrinolysis were evaluated.Results: Shear‐induced platelet aggregation was increased in the stenosis group (69.0 ± 10.6%) compared with the controls (57.7 ± 10.3%, p < 0.0001). Patients with severe stenosis in the proximal segments had significantly increased SIPA (p< 0.0001) and vWF larger multimer concentration (p < 0.0001) compared with the control group. A significant correlation existed between SIPA and the vWF larger multimer concentrationinall subjects studied (r= 0.422, p<0.0001).Conclusions: Shear‐induced platelet aggregation is increased in patients with severe stenosis of the proximal coronary arteries and correlates with plasma concentrations of vWF larger multimers, suggesting that severe stenosis in the proximal segments is not only associated with an increased risk of significant my ocardial ischemia, but may also generate high shear stress in the stenosed artery and increase plasma vWF larger multimers, thereby promoting the formation of platelet thrombi.
The effect of aortic valve replacement on N‐terminal natriuretic propeptides in patients with aortic stenosis
Authors: Qi Wei , Mathisen Per , Kjekshus John , Simonsen Svein , Endresen Knut , Bjørnerheim Reidar , Hall Christian 
Published: June 2007

AbstractBackground: Increased plasma concentrations of natriuretic peptides have been demonstrated to be associated with increased intracardiac pressure and left ventricular (LV) hypertrophy. After aortic valve replacement (AVR) in aortic stenosis patients, there is a relief of the left outflow obstruction with a substantial hemodynamic improvement. This is followed by a gradual regression of the LV hypertrophy.Hypothesis: After AVR, reduction in LV filling pressure is expected to occur rapidly, while regression of LV hypertrophy will take place over a longer time period. On this basis we hypothesized that the plasma levels of N‐terminal proatrial natriuretic peptide (NT‐proANP) would be reduced early in the postoperative period, while N‐terminal probrain natriuretic peptide (NT‐proBNP), through its closer reflection of LV hypertrophy, would be sustained for a longer period.Methods: Two groups of patients with aortic stenosis undergoing AVR were followed for 4 and 12 months, respectively. Plasma concentrations of NT‐pro ANP and NT‐proBNP were measured before and after AVR and related to preoperative findings and changes in the aortic valve area index.Results: Before AVR, the patients had significantly increased plasma levels of NT‐pro ANP and NT‐proBNP. After AVR, NT‐ pro ANP was decreased at 4 and 12 months but remained elevated compared with controls. N‐terminal‐proBNP tended to decrease, but did not change significantly. When the patients were followed for 12 months, only those with elevated preoperative pulmonary capillary wedge pressure had decreased peptide levels (NT‐proANP: p = 0.017, NT‐proBNP: p = 0.058). There was no regression of LV hypertrophy. The patients with the largest postoperative valve area index [1.27 (1.10‐1.55) cm2/m2] had the largest reduction of NT‐proBNP (47%). Those with the smallest valve area index [0.67 (0.54‐0.73) cm2/m2] had no decrease in NT‐proBNP.Conclusions: Our study suggests that a reduction in left atrial pressure is the main factor causing the change of NT‐proANP level after AVR. A small prosthetic valve orifice area with a high aortic valve gradient might prevent regression of LV hypertrophy, thus representing a stimulus for increased cardiac secretion of NT‐proBNP.
New parameters in the interpretation of exercise testing in women: QTC dispersion and QT dispersion ratio difference
Authors: Özdemr Kurtuluş , Altunkeser Bulent B. , Aydin Mustafa , Özeren Ali , Dams Gulizar , Gok Hasan 
Published: June 2007

AbstractBackground: It has been reported that the increase of QT dispersion (QTD) that occurs due to increased inhomogeneity of the ventricular repolarization because of transient ischemia obtained by standard 12‐lead electrocardiogram (ECG), the changes during exercise, and the differences between exercise and rest increase the accuracy of exercise test in the diagnosis of coronary artery disease (CAD).Hypothesis: This study was designed to investigate the value of QTD parameters, which are reported to increase the diagnostic accuracy of exercise test in women.Methods: Ninety‐seven women who had undergone coronary angiography and exercise test were evaluated for diagnosis of chest pain. QT dispersion was calculated using the measurements of the highest and lowest values of QT interval obtained by ECG during peak exercise. The QTc using Bazett's equation, and the QTD ratio (QTDR) using QT/RR were calculated, and QTcD and QTD ratios were obtained. The difference between QTcD and QTDR was determined by extracting the rest values from the exercise values.Results: The groups with normal coronaries (n = 48), single‐vessel CAD (n= 24), and multivessel CAD (n= 25) were compared. The obtained QTD parameters at peak exercise and their differences between exercise and rest were found to be significantly increased in patients with CAD (p<0.001).Furthermore, these parameters were found to be higher in the patients with multivessel CAD than in those with single‐vessel disease (p < 0.05). With the parameters QTcD > 60 ms and QTDR > 10%, greater sensitivity and specificity were obtained compared with ST‐segment depression. The highest diagnostic accuracy was obtained with the QTD parameters calculated from the differences between rest and exercise values. The diagnostic accuracy of the difference of QTcD > 15 ms and the difference of QTDR > 5% was relatively higher than the other parameters (sensitivity, specificity, and negative and positive predictor values are 84,88,84, 87% and 84, 96, 85, 95%, respectively).Conclusion: The use of QTD parameters as variables of ECG, which is easily obtainable in the evaluation of exercise ECG in women, increases the diagnostic accuracy of the exercise test. In addition, the evaluation of QTD variables may provide information about the incidence of CAD.
The effect of intracoronary fibroblast growth factor‐2 on restenosis after primary angioplasty or stent placement in a pig model of atherosclerosis
Authors: Post Mark J. , Laham Roger J. , Kuntz Richard E. , Novicki Deborah , Simons Michael 
Published: June 2007

AbstractBackground: Therapeutic angiogenesis, if combined with primary percutaneous transluminal coronary angioplasty or stent placement, could improve the outcome of patients suffering from multifocal coronary disease.Hypothesis: Because of the concern that angiogenic growth factors might promote restenosis, we studied the effect of a single intracoronary administration of recombinant fibroblast growth factor (rFGF)‐2 on restenosis after balloon angioplasty and stent placement in a pig model of coronary atherosclerosis.Methods: In 24 Yucatan minipigs, coronary lesions were induced by arterial injury and 3 months of atherogenic diet. After 3 months, repeat catheterization was performed with balloon dilation or stent placement at the injured sites, with a follow‐up of 6 weeks. Results were monitored using quantitative angiography, intravascular ultrasound (IVUS), and histomorphometry.Results: Intracoronary rFGF‐22 μg/kg did not affect neoin‐tima formation or remodeling in this model. A small but significant aggravation of late lumenloss was observed in the reference segments of the rFGF‐2‐treated group. Angiographic and echographic late lumen loss, intimal hyperplasia, and arterial remodeling, as well as histologic neointima were all similar in the rFGF‐2‐ and the vehicle‐treated group. Confirming earlier studies from our group and those of others, stented arteries compared with balloon‐dilated arteries had increased angiographic late lumen loss, a trend toward increased intimal hyperplasia and decreased remodeling.Conclusion: We conclude that rFGF‐2 does not aggravate restenosis after balloon dilation or stenting in this pig model of coronary atherosclerosis. Future combinations of angioplasty and therapeutic angiogenesis in a single session should be pursued as a feasible and safe strategy.
Cardioversion of atrial fibrillation with ibutilide: When is it most effective?
Authors: Das Mithilesh Kumar , Cheriparambil Kuruvilla , Bedi Ashwini , Kassotis John , Reddy Chatla V. R. , Saul Barry , Makan Majesh 
Published: June 2007

AbstractBackground: Atrial fibrillation (AF) is found in 1% of persons above the age of 60 years. More than 5% of the population older than 69 years and about 14% of octogenarians are at risk for this arrhythmia. It is estimated that 1.5 to 3 million persons in the United States alone suffer from AF. The public health implications and attendant morbidity are a significant drain on our health care system.Hypothesis: The purpose of this study was to determine the clinical and echocardiographic predictors of success in converting AF of ≥ 24 h duration.Methods: Demographic and clinical and echocardiographic parameters of 101 patients with recent onset AF (> 24 h) who received ibutilide were studied.Results: Of 101 patients, 56 (55%) converted to sinus rhythm. Age, gender, hypertension, diabetes mellitus, left ventricular ejection fraction (≤ 35%), congestive heart failure, and previous medication for rate control had no significant effect on the conversion rate. Conversion rate was only 30% (9/30 patients) in the presence of an enlarged left atrium (LA > 5 cm) and 37.7% (23/61 patients) in the presence of mitral valve disease (MVD), whereas the conversion rate was 82.5% (33/40 patients) in the absence of MVD and 85% (29/34 patients) in the absence of both enlarged LA and MVD (p =< 0.001). Patients with coronary artery disease (CAD) also exhibited a significantly greater response to ibutilide than patients without CAD (77 vs. 46%, p‐value 0.005).Conclusion: As a therapy for cardioversion of AF, ibutilide is most effective in a selected subgroup patients, such as in patients with CAD and in patients without MVD and/ormarkedly enlarged left atrium.
Triggering effect of physical and mental stress on spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter‐defibrillators
Authors: Fries Roland , König Jochem , Schäfers Hans‐Joachim , Böhm Michael 
Published: June 2007

AbstractBackground: Physical and mental stress as well as sexual activity are potential triggering factors of acute coronary events and sudden cardiac death.Hypothesis: These factors may also trigger recurrence of spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter‐defibrillators (ICDs).Methods: We performed a case‐crossover study in 43 consecutive patients with 95 symptomatic, ICD‐documented tachyarrhythmic events and calculated the relative risk of tachyarrhythmia recurrence during physical and mental stress. Physical and mental activity was graded on a 4‐step intensity scale, and stress was defined as physical exertion or mental stress with an intensity grade ≥ II during or up to 1 h before arrhythmia recurrence. Relative risk was determined taking into account the habitual weekly stress frequency of each patient.Results: Physical stress was present in 26% (n = 25), mental stress in 24% (n = 23), and sexual activity in 2% (n = 2) of analyzed events. The weekly habitual stress frequency was 8 ± 8 (median 7) for physical stress, 6 ± 6 (median 4) for mental stress, and 0.5 ± 0.5 (median 0.25) for sexual activity. Thus, relative risk of arrhythmia recurrence during the presence of stress was 7.5 for physical activity (95% confidence interval [CI] 5.2–11.1), 9.5 (CI 6.3–14.5) for mental activity, and 7.5 (CI 2.3–24.8) for sexual activity.Conclusions: Physical and mental stress as well as sexual activity are factors that significantly increase relative risk of spontaneous recurrence of sustained ventricular tachyarrhythmias in patients with ICDs. Consideration of this stress‐related relative risk increase may contribute to avoidance of harmful shock delivery in ICD recipients.
Effects of simvastatin, an HMG‐CoA reductase inhibitor, in patients with hypertriglyceridemia
Authors: Isaacsohn Jonathan , Hunninghake Donald , Schrott Helmut , Dujovne Carlos A. , Knopp Robert , Weiss Stuart R. , Bays Harold , Crousei John R. , Davidson Michael H. , Keilson Leonardm , McKenney James , Korenman Stanleyg , Dobs Adrians , Stein Evan , Krauss Ronald M. , MacCubbin Darbie , Cho Meeh Yung , Plotkin Diane J. , Mitchel YALE B. 
Published: June 2007

AbstractBackground: Patients with elevated levels of serum triglyc‐erides (TG) often have other associated lipid abnormalities (e.g., low levels of high‐density lipoprotein cholesterol [HDL‐C]) and are at increased risk of developing coronary heart disease. Although the therapeutic benefits of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors (statins) in hypercholesterolemic patients have been well established, less is known about the effects of statins in patient populations with hypertriglyceridemia.Hypothesis: The purpose of this study was to evaluate the lipoprotein‐altering efficacy of simvastatin in hypertriglyceri‐demic patients.Methods: This was a multicenter, randomized, double‐blind, placebo‐controlled study. In all, 195 patients with fasting serum triglyceride levels between 300 and 900 mg/dl received once daily doses of placebo or simvastatin 20,40, or 80 mg for 6 weeks.Results: Compared with placebo, simvastatin treatment across all doses resulted in significant reductions (p < 0.05–<0.001) in serum levels of triglycerides (‐20 to–31% decrease) and TG‐rich lipoprotein particles. Significant (p< 0.001) reductions were also seen in low‐density lipoprotein cholesterol (‐25 to‐35%)andnon‐HDL‐C(‐26to‐40%). Levels of HDL‐C were increased (7‐11%) in the simvastatin groups compared with placebo (p < 0.05‐ < 0.001).Conclusion: The results of this study demonstrate the beneficial effects of simvastatin in patients with hypertriglyceridemia.
Prevalence and risk factors for erectile dysfunction in men with diabetes, hypertension, or both diseases: A community survey among 1,412 Israeli men
Authors: Roth Are , Kalter‐Lftbovhx Ofra , Kerbis Yehuda , Tekenbaum‐Koren Ella , Chen Juza , Sobol Tamar , Raz Ilamar 
Published: June 2007

AbstractBackground: Erectile dysfunction (ED) and cardiovascular disease share common risk factors and may be further aggravated by medical treatment for reducing them.Hypothesis: The study was undertaken to assess the prevalence of ED in patients with diabetes (DM), hypertension (HTN), or both diseases, and to evaluate the effect of patient age, medical treatment, and disease duration and control on the prevalence of ED in tins population.Methods; A group of 150 primary practitioners who had patients with known DM and or HTN conducted a survey. utilizine IIEF‐15, a 15‐itemmultidunensional. self‐admnistered questionnaire used for the clinical assessment of ED.Results: In all, 1,412 patients were included: 37%liadDM, 38% had HTN, and 25% had both diseases. Then mean age was 55,58, and 60 yean, and 62,46, and 67% had some degree of ED, respectively The prevalence of ED increased with age and disease duration m each age group and was higher in subjects with DM than in those with HTN, especially in those aged < 65 years. Poor glycemic control was associated with a higher prevalence rate of ED early in the course of the disease. There was no significant difference in the prevalence of ED according to type and number of antihypertensive drugs.Conclusions: Erectile dysfunction is common among patients at high risk for cardiovascular disease because of diabetes and or HTN. Diabetic men are affected earlier than those wife HTN. Given the high frequency of ED in young patients wife these risk tartars, physicians should encourage an open discussion on the subject during routine visits to promote early detection and treatment.
Matrix metalloproteinases and coronary artery diseases
Authors: Ikeda Uichi , Shimada Kazuyuki 
Published: June 2007

AbstractMatrix metalloproteinases (MMPs) play an important role in cardiovascular remodeling by degrading the extracellular matrix. Enhanced MMP expression has been detected in the atherosclerotic plaque, and activation of MMPs appears to be involved in the vulnerability of the plaque. Circulating MMP levels are elevated in patients with acute myocardial infarction and unstable angina. Increased MMP expression is also observed after coronary angioplasty, which is related to late loss index after the procedure. These observations suggest that MMP expression may be not only related to instability of the plaque, but also to the formation of restenotic lesions. The development of therapeutic drugs targeted specifically against MMPs may be useful in the prevention of atherosclerotic lesion development, plaque rupture, and restenosis.
Understanding implantable cardioverter defibrillator shocks and storms: Medical and psychosocial considerations for research and clinical care
Authors: Sears Samuel F. , Conti Jamie B. 
Published: June 2007

AbstractThe experience of shock is the distinguishing feature for patients with implantable cardioverter defibrillators (ICDs) and is associated with diminished psychological functioning and quality of life. Multiple shocks and ICD storm are a relatively common event among patients with ICDs (10‐20%) and may present specific challenging medical and psychological management for the attending health care providers. This paper examines the medical and psychological aspects of ICD shocks and storms and describes a model of biopsychosocial management for patients following the experience of ICD storm. Successful management of patients post shock includes the use of antiarrhythmic medications and careful attention to the causality of the shocks via stored electrograms. The psychological management includes specific attention to debriefing post‐shock feelings and attributions, preventing avoidance behavior, and facilitating positive “return to life” actions. Preliminary research examining formal psychosocial treatment supports a cognitive behavioral strategy to reduce psychological distress and facilitate quality of life. Collectively, these data suggest that interdisciplinary management of patients with multiple ICD shocks or the experience of ICD storm is advised, and routine psychological consultation may be indicated for the patient post ICD storm to reduce the possibility of symptoms of post‐traumatic stress.