bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gender Differences in Patients Referred for Atrial Fibrillation Management to a Tertiary Center
Authors: ROTEN LAURENT , RIMOLDI STEFANO F. , SCHWICK NICOLA , SAKATA TAKAO , HEIMGARTNER CHRIS , FUHRER JUERG , DELACRÉTAZ ETIENNE , TANNER HILDEGARD 
Published: April 2009

Background: Atrial fibrillation (AF) ablation is less frequently performed in women than in men. Although the prevalence of AF is slightly higher in men, this does not fully account for the lower number of AF ablations performed in women. This study sought to examine the effect of gender on referral for AF and subsequent AF management.
Methods: Consecutive patients referred to our tertiary arrhythmia outpatient clinic for AF management were retrospectively analyzed.
Results: Of 264 patients referred, only 27% were women. Women were older than men (63 ± 9 vs 58 ± 11 years, P = 0.002), more often had paroxysmal AF (78% vs 63% in men, P = 0.022), and women more frequently complained about palpitations (71% vs 49%, P = 0.002). In addition, they had more often experienced amiodarone side effects than men (56% vs 36%, P = 0.046). In this referred population, there was no difference in the proportion of women and men undergoing AF ablation immediately following the initial evaluation (21% vs 25%, P = ns), at any time during the follow‐up (38% vs 44%, P = ns), and there was no difference in the proportion of patients undergoing atrioventricular node ablation in both sexes (6% of women vs 3% of men, P = ns).
Conclusions: There is an important difference in the proportion of men and women referred for management of AF in a specialized outpatient arrhythmia clinic, with women being referred three times less often than men. However, there is no gender‐related difference in the subsequent treatment decisions. These findings emphasize the importance of focusing on management of symptomatic AF in women.
Does Bipolar Pacemaker Current Activate Blood Platelets?
Authors: GJESDAL GRUNDE , BO HANSEN ANNEBIRTHE , BRANDES AXEL 
Published: April 2009

Objective: The aim of this study was to investigate whether bipolar pacemaker current lead can activate blood platelets. The null hypothesis was that 1 minute of electrical stimulation of platelets would not influence their subsequent reactivity to adenosine diphosphate (ADP).
Background: Both platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets, to the depolarizing current. Platelet activation may ensue, resulting in aggregation, release reaction, and contraction. In contrast, a unipolar pacemaker system will not depolarize blood, but transmit current directly into the myocardium, and the current afterward passes through other tissues before returning to the pacemaker can.
Methods: Platelet‐rich plasma was prepared from two healthy subjects. Platelet reactivity to the agonist ADP was tested in paired samples in an aggregometer in a case/control setup.
Results: Eighteen of 46 tested pairs of platelet‐rich plasma showed increased reactivity in the paced sample; 26 were unchanged while two showed decreased reactivity in the paced sample. Using a two‐sided sign test, the null hypothesis was rejected (P = 0.0004).
Conclusions: The study demonstrates increased reactivity to ADP in platelets exposed in vitro to stimulation by pacemaker current. The clinical relevance of these findings remains to be investigated.
Predictors of Syncope in Patients with Hypertrophic Cardiomyopathy
Authors: HAGHJOO MAJID , FAGHFURIAN BABAK , TAHERPOUR MEHDI , FAZELIFAR AMIR FARJAM , MOHAMMADZADEH SHABNAM , ALIZADEH ABOLFATH , SADR‐AMELI MOHAMMAD ALI 
Published: April 2009

Background: Approximately 30% of patients with hypertrophic cardiomyopathy (HCM) suffer syncope and syncope was the only symptom associated with sudden death. However, no systematic studies in large cohorts looking at predictors of syncope are available in the literature. Therefore, we sought to determine predictors of syncope in patients with HCM.
Methods: One hundred and seventy‐three consecutive patients with HCM and a mean age of 42 ± 18 years (range 10–78) underwent extensive clinical, electrocardiographic, and echocardiographic testing to identify predictors of syncope.
Results: During the mean follow‐up duration of 50 months, syncope occurred in 28% of the HCM patients. Univariate analysis showed male gender, age <40 years, family history of sudden death, PR interval, QRS width, ≥2 bursts of nonsustained ventricular tachycardia (NSVT), ≥3 bursts of nonsustained supraventricular tachycardia (NSSVT), maximum left ventricular wall thickness ≥30 mm, and abnormal blood pressure response, out of 24 demographic, clinical, hemodynamic, electrocardiographic, and echocardiographic features, to be significantly associated with syncope. Of these nine variables, the only independent predictors of syncope at multivariate analysis were age <40 years (odds ratio [OR]: 4.4, 95% confidence interval [CI]: 2.2–16, P = 0.003), ≥2 bursts of NSVT (OR: 9.9, 95% CI: 2.0–46, P = 0.0001), and ≥3 bursts of NSSVT (OR: 2.7, 95% CI: 0.38–8.25, P = 0.001). The concomitant occurrence of all three variables had a sensitivity of 87% and specificity of 73% in identifying the patients with syncopal events.
Conclusions: The results of this study showed that age <40 years, bursts of NSVT, and NSSVT were independently associated with the risk of syncope in patients with HCM. Demographic data and ambulatory ECG findings could help in risk stratification of patients with HCM.
Long‐Term Sinus Rhythm Stability after Intraoperative Ablation of Permanent Atrial Fibrillation
Authors: DENEKE THOMAS , KHARGI KRISHNA , VOSS DOMINIK , LEMKE BERND , LAWO THOMAS , LACZKOVICS AXEL , MÜGGE ANDREAS , BÖSCHE LEIF‐ILJA , LINDSTAEDT MICHAEL , GERMING ALFRIED , HORLITZ MARC , GREWE PETER H. , FRITZ MARKUS 
Published: April 2009

Introduction: Short‐ and medium‐term sinus rhythm (SR) rates after intraoperative radiofrequency ablation to treat permanent atrial fibrillation (AF) are well documented. Is rhythm success stable during a long‐term follow‐up?
Methods and Results: A total of 130 patients who had undergone intraoperative radiofrequency cooled‐tip endocardial ablation (SICTRA) of permanent AF (mean AF duration 6±5 years) concomitant to open heart surgery more than 3 years ago were followed up using electrocardiogram (ECG), Holter‐ECG, and echocardiography and compared with 12‐month follow‐up data. In 55% of patients, only the left atrium and in 45%, both atria were treated using SICTRA. Mitral valve replacement was performed in 21, mitral valve reconstruction in 25, aortic valve replacement in 13, CABG procedures in 51 (including 11 patients with additional mitral valve surgery), and complex procedures in 20 patients. Sixty‐nine percent of patients (90/130) were in stable SR after a median period of 48 months, whereas 28% (36/130) were in AF and 3% (4/130) were in atrial flutter. In between the 12‐month follow‐up and the long‐term follow‐up, seven patients converted to AF after having documented SR, two patients converted to typical right atrial flutter after being in SR, and two patients from AF to left atrial macroreentry. After left and biatrial SICTRA, SR rates were comparable (73% vs 66%, P = 0.45). Echocardiography revealed 73% of patients in SR to have effective left atrial contraction.
Conclusions: SICTRA restores long‐term stable SR in 69% of all patients. Nine percent of patients reconverted back to atrial arrhythmia after having documented SR at 12 months.
Head‐to‐Head and Extrapolated Comparisons of Different Drug‐Eluting Stents: Differences in Late Loss, Restenosis, and Clinical Outcomes
Authors: HELLIGE GERRIT , WINDECKER STEPHAN 
Published: April 2009

Drug‐eluting stents (DES) have been appraised as breakthrough technology owing to their potent reduction of restenosis, an important nuisance in the quality of life of affected patients, the rare cause of myocardial infarction, and the principal shortcoming compared with coronary artery bypass surgery. First‐generation DES with controlled release of sirolimus or paclitaxel from durable polymers have been attested to reduce the need of target lesion revascularization by 40% to 70% compared with bare metal stents (BMS) requiring treatment of only eight patients (number needed to treat [NNT] 6–10) in order to prevent one revascularization event. The benefit, albeit attenuated, persisted in studies without protocol‐mandated angiographic follow‐up, was particularly pronounced in diabetic patients, and endured during long‐term follow‐up extending to 5 years. While the therapeutic benefit of first‐generation DES has primarily been established as compared against BMS, more recent investigations have concentrated on direct head‐to‐head comparisons between various DES. To date, a number of newer‐generation DES are already in clinical use or under investigation with newly designed stent platforms, improved polymer coatings, and a variety of different drugs. This review will address differences between various DES platforms in terms of angiographic and clinical outcomes. Moreover, the differential outcome of DES in several important patient subgroups will be analyzed.
Performance of Everolimus‐Eluting Stents: Pooled Analysis from the SPIRIT Trials
Authors: MIU RAYMOND , SERRUYS PATRICK W. , STONE GREGG W. 
Published: April 2009

Background: First‐generation drug‐eluting stents (DES) still have significant rates of restenosis and stent thrombosis, especially in complex lesions. A second‐ generation stent eluting everolimus from a thin, non‐adhesive, non‐inflammatory durable polymer coated onto a low‐profile, cobalt‐ chromium stent has been developed and evaluated in patients with coronary artery disease.
Methods: Following the SPIRIT First proof‐of‐concept trial, the everolimus‐eluting stent (EES) was compared to a widely used paclitaxel‐eluting stent (PES) in patients with non‐complex coronary artery disease in 2 successive randomized trials in Europe and Asia (SPIRIT II) and the United States (SPIRIT III). The databases from these trials were pooled for a patient‐level meta‐analysis.
Results: Collectively, the SPIRIT II and SPIRIT III trials randomized 1,302 patients to either EES (n = 892) or PES (n = 410), with a total of 1,501 randomized lesions treated. EES compared to PES resulted in reduced mean in‐segment late loss (0.11 ± 0.37 vs. 0.22 ± 0.44 mm, P = 0.0004) and binary angiographic restenosis (4.1% vs. 7.8%, P = 0.039) at 6–8 months. The 30‐day rates of myocardial infarction (MI) were lower with EES than PES (1.0% vs. 2.9%, P = 0.02). At 1‐year, EES compared to PES resulted in reduced rates of target lesion revascularization (TLR; 3.1% vs. 5.8%, P = 0.02), a trend toward less MI (2.3% vs. 4.0%, P = 0.08), and comparable rates of cardiac death (0.6% vs. 1.0%, P = 0.39) and stent thrombosis (0.7% vs. 0.8%, P = 0.90). As a result, patients treated with EES compared to PES had significantly reduced rates of major adverse cardiac events (cardiac death, MI, or TLR) at 1 year (5.2% vs. 10.0%, P = 0.002).
Conclusions: The EES stent is a second‐generation DES which results in improved clinical and angiographic outcomes compared to PES at 1 year. Longer‐term follow‐up from these trials and larger comparative trials are under way to evaluate the durability and utility of this device in more complex patients and lesions.
Choice of DES: A US Clinician's Perspective
Authors: POP ANDREI , GRINES CINDY L. 
Published: April 2009

With the advent of the second‐generation drug‐eluting stents, the decision process on which stent to use is becoming increasingly complex. Our article compares the technical characteristics of the four drug‐eluting stents (DES) currently available in the United States. We review the data that led to the approval of each stent and analyze the literature comparing their performance in various patient subgroups. Finally, we present our current practice and identify a “wish list” for the ideal DES.
Comparison of Quantitative T‐Wave Alternans Profiles of Healthy Subjects and ICD Patients
Authors: De Vilhena Garcia Euler , Samesima Nelson , Filho Horácio G. Pereira , Quadros Cristina M. , Da Silva Luis Tenório Cavalcante , Filho Martino Martinelli , Hannouche Maria Luciana Zacharias , Mathias Jr Wilson , Pastore Carlos Alberto 
Published: April 2009

Background: Current relevance of T‐wave alternans is based on its association with electrical disorder and elevated cardiac risk. Quantitative reports would improve understanding on TWA augmentation mechanisms during mental stress or prior to tachyarrhythmias. However, little information is available about quantitative TWA values in clinical populations. This study aims to create and compare TWA profiles of healthy subjects and ICD patients, evaluated on treadmill stress protocols. Methods: Apparently healthy subjects, not in use of any medication were recruited. All eligible ICD patients were capable of performing an attenuated stress test. TWA analysis was performed during a 15‐lead treadmill test. The derived comparative profile consisted of TWA amplitude and its associated heart rate, at rest (baseline) and at peak TWA value. Chi‐square or Mann‐Whitney tests were used with p values ≤ 0.05. Discriminatory performance was evaluated by a binary logistic regression model. Results: 31 healthy subjects (8F, 23M) and 32 ICD patients (10F, 22M) were different on baseline TWA (1 ± 2 μV; 8 ± 9 μV; p < 0.001) and peak TWA values (26 ± 13 μV; 37 ± 20 μV; p = 0,009) as well as on baseline TWA heart rate (79 ± 10 bpm; 67 ± 15 bpm; p < 0.001) and peak TWA heart rate (118 ± 8 bpm; 90 ± 17 bpm; p < 0.001). The logistic model yielded sensitivity and specificity values of 88.9% and 92.9%, respectively. Conclusions: Healthy subjects and ICD patients have distinct TWA profiles. The new TWA profile representation (in amplitude‐heart rate pairs) may help comparison among different research protocols.
Correlation of Noninvasive Electrocardiography with Invasive Electrophysiology in Syncope of Unknown Origin: Implications from a Large Syncope Database
Authors: Gatzoulis Konstantinos A. , Karystinos George , Gialernios Theodoros , Sotiropoulos Helias , Synetos Andreas , Dilaveris Polychronis , Sideris Skevos , Kalikazaros Ioannis , Olshansky Brian , Stefanadis Christodoulos I. 
Published: April 2009

Background: The evaluation of syncope can be expensive, unfocussed, and unrevealing yet, failure to diagnose an arrhythmic cause of syncope is a major problem. We investigate the utility of noninvasive electrocardiographic evaluation (12‐lead ECG and 24‐hour ambulatory electrocardiographic recordings) to predict electrophysiology study results in patients with undiagnosed syncope. Methods: We evaluated 421 patients with undiagnosed syncope who had an electrocardiogram (ECG), an electrophysiology study, and 24‐hour ambulatory monitoring. Noninvasive testing was used to predict electrophysiology testing outcomes. Multivariable logistic regression analysis adjusting for age, sex, presence of heart disease, and left ventricular ejection fraction (LVEF) was used to assess independent predictors for sinus node disease, atrioventricular node disease, and induction of ventricular tachyarrhythmias. Results: Patients were divided into four groups: group 1, abnormal ECG and ambulatory monitor; group 2, abnormal ECG only; group 3, abnormal ambulatory monitor; and group 4, normal ECG and ambulatory monitor. The likelihood of finding at least one abnormality during electrophysiologic testing among the four groups was highest in group 1 (82.2%) and lower in groups 2 and 3 (68.1% and 33.7%, respectively). In group 4, any electrophysiology study abnormality was low (9.1%). Odds ratios (OR) were 35.9 (P < 0.001), 17.8 (P < 0.001), and 3.5 (P = 0.064) for abnormal findings on electrophysiology study, respectively (first three groups vs the fourth one). ECG and ambulatory monitor results predicted results of electrophysiology testing. Conclusion: Abnormal ECG findings on noninvasive testing are well correlated with potential brady‐ or/and tachyarrhythmic causes of syncope, in electrophysiology study of patients with undiagnosed syncope.
Quinidine for Pharmacological Cardioversion of Atrial Fibrillation: A Retrospective Analysis in 501 Consecutive Patients
Authors: Schwaab Bernhard , Katalinic Alexander , Böge Uta Maria , Loh Jürgen , Blank Peter , Kölzow Tatjana , Poppe Dirk , Bonnemeier Hendrik 
Published: April 2009

Background:Although quinidine has been used to terminate atrial fibrillation (AFib) for a long time, it has been recently classified to be used as a third‐line‐drug for cardioversion. However, these recommendations are based on a few small studies, and there are no data available of a larger modern patient population undergoing pharmacological cardioversion of AFib. Therefore, we evaluated the safety of quinidine for cardioversion of paroxysmal AFib in patients after cardiac surgery and coronary intervention.Methods:In 501 consecutive patients (66 ± 9 years, 32% women), 200–400 mg of quinidine were administered every 6 hours until cardioversion or for a maximum of 48 hours. Patients were included with QT interval ≤450 ms, ejection fraction (EF) ≥35%, and plasma potassium >4.3 mEq/L. Exclusion criteria were: unstable angina, myocardial infarction <3 months, and advanced congestive heart failure. Patients received verapamil, beta‐blockers, or digitalis to slow down ventricular rate <100 bpm.Results:Quinidine therapy did not have to be stopped due to adverse drug reactions (ADR), and no significant QTc interval prolongation (Bazett and Fridericia correction) and no life‐threatening ventricular arrhythmia occurred. Mean quinidine dose was 617 ± 520 mg and 92% of the patients received verapamil or beta‐blocker to decrease ventricular rate. Cardioversion was successful in 84% of patients. All ADRs were minor and transient. Multivariate analysis revealed female gender (OR 2.62, CI 1.61–4.26, P < 0.001) and EF 45–54% (OR 1.97, CI 1.15–3.36, P = 0.013) as independent risk factors for ADRs.Conclusions:Quinidine for pharmacological cardioversion of AFib is safe and well tolerated in this subset of patients.
Familial Aggregation and Heritability of Electrocardiographic Intervals and Heart Rate in a Rural Chinese Population
Authors: Li Jianping , Huo Yong , Zhang Yan , Fang Zhian , Yang Jianhua , Zang Tonghua , Xu Xiping , Xu Xin 
Published: April 2009

Background: Estimates of the genetic influences on electrocardiographic (ECG) parameters are inconsistent in previous reports, and no such studies have been performed in China. So we estimated genetic contributions to PR and QRS intervals and the rate‐adjusted QT interval (Bazett's QTc) in a Chinese rural population. Methods: A total of 2909 subjects from 847 families were enrolled in the current study. Genetic contributions to ECG parameters were estimated in two ways: correlation coefficients among family members (father‐mother, parent‐offspring, first sibling‐other sibling) and the heritability of each of the ECG parameters. Results: Our results showed significant correlations among family members on theses parameters: the correlation coefficients for PR interval, QRS duration, QTc interval, and HR, between parent‐sibling, and sibling‐sibling were 0.17 and 0.13, 0.18 and 0.23, 0.22 and 0.28, 0.19 and 0.18, respectively. The heritability for PR interval, QRS duration, QTc interval, and HR were estimated as 0.34, 0.43, 0.40, and 0.34, respectively. Conclusion: Genetic factors, together with the environmental and other cofactors contribute no more than 60% to the variance of the ECG intervals, supporting the concept that multiple factors, including gene‐gene and gene‐environment interactions could influence ECG interval phenotypes, and genetic factors play a major role.
Correlation of Electrical and Mechanical Reverse Remodeling after Cardiac Resynchronization Therapy
Authors: Kamireddy Swapna , Agarwal Sunil Kumar , Adelstein Evan , Jain Sandeep , Saba Samir 
Published: April 2009

Background: Cardiac resynchronization therapy (CRT) improves clinical outcome in many patients with refractory heart failure (HF). This study examined whether CRT is associated with reverse electrical remodeling by surface electrocardiogram (ECG). Methods: Consecutive CRT recipients at the University of Pittsburgh Medical Center with >90 days of follow‐up were included in this analysis. ECG data were abstracted from medical records. Subjects with a relative increase of ≥15% in left ventricular ejection fraction (LVEF) after CRT were considered responders. Results: A total of 113 patients (age 69 ± 11 years, men 70%, white 92%) were followed for a mean duration of 407 ± 290 (92–1439) days. Overall, LVEF increased after CRT (29 ± 13% vs 24 ± 9%; P < 0.01) and 50% of patients were responders. The mean native QRS interval among responders was higher than in nonresponders (163 ± 32 ms vs 148 ± 29 ms; P < 0.01). More than 3 months after CRT, there was no change in the paced QRS duration compared to baseline. Paced QRS duration, however, decreased among responders and increased among nonresponders and was significantly different by response status (P < 0.001). There was a significant correlation between increase in LVEF and decrease in paced QRS width in the overall population (r =−0.3; P < 0.01). Conclusions: Among responders to CRT, the paced QRS width decreases significantly, whereas it increases among nonresponders. Given the paced nature of the QRS, the improved conduction probably reflects enhanced cell‐to‐cell coupling after CRT as opposed to improved conduction within the His‐Purkinje system. These findings have significant implications as to the mechanisms of benefit from CRT.
ST Segment “Hump” during Exercise Testing and the Risk of Sudden Cardiac Death in Patients with Hypertrophic Cardiomyopathy
Authors: Michaelides Andreas P. , Stamatopoulos Ilias , Antoniades Charalambos , Anastasakis Aris , Kotsiopoulou Christina , Theopistou Artemisia , Misailidou Maria , Fourlas Christos , Elliott Perry M. , Stefanadis Christodoulos 
Published: April 2009

Background:The appearance of a discrete upward deflection of the ST segment termed “the ST hump sign” (STHS) during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise.Objective:We investigated the prevalence and clinical significance of this sign in a population of patients with hypertrophic cardiomyopathy.Methods:Eighty‐one patients with hypertrophic cardiomyopathy (HCM) who underwent cardiopulmonary exercise testing were followed in a retrospective cohort study for a mean period of 5.3 years.Results:The appearance of the STHS at the peak of exercise testing was observed in 42 patients (52%), particularly in the inferior and the lateral leads. Patients with the STHS had higher fractional shortening and maximum left ventricular wall thickness and exhibited more frequently outflow tract gradient >30 mmHg at rest. Furthermore, the presence of STHS was a strong independent predictor of the risk of sudden cardiac death (SCD), as the latter occurred in eight of the patients with this sign (8/42, 19%) and in none of the patients without it (0/39, 0%) (P < 0.001).Conclusion:The appearance of a “hump” at the ST segment during exercise testing appears to be a risk factor for SCD in patients with HCM. However, further studies are necessary to validate this finding in larger populations and to elucidate the mechanism of the appearance of the “hump.”