bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevalence of Mechanical Dyssynchrony in Heart Failure Patients with Different QRS Durations
Authors: HAGHJOO MAJID , BAGHERZADEH ATAALLAH , FAZELIFAR AMIR FARJAM , HAGHIGHI ZAHRA OJAGHI , ESMAIELZADEH MARYAM , ALIZADEH ABOLFATH , EMKANJOO ZAHRA , SADEGHPOUR ANITA , SAMIEI NILOOFAR , FARAHANI MARYAM MOSHKANI , SADR‐AMELI MOHAMMAD ALI , MALEKI MAJID , NOOHI FEREIDOUN 
Published: May 2007

Background:

Cardiac resynchronization therapy (CRT) has emerged as an established therapy for congestive heart failure. However, up to 30% of patients fail to respond to CRT despite prolonged QRS.
Objectives:

This study aimed at defining the prevalence of interventricular and intraventricular dyssynchrony in heart failure patients with different QRS durations.
Methods:

A total of 123 consecutive patients with severe heart failure (LVEF < 35% and NYHA class III–IV) were prospectively evaluated using 12‐lead electrocardiogram and complete echocardiographic examination including tissue Doppler imaging.
Results:

According to the QRS duration, 56 patients had a QRS duration ≤120 ms (Group 1), 33 patients had a QRS duration between 120 and 150 ms (Group 2), and 34 patients had a QRS duration ≥150 ms (Group 3). Intraventricular dyssynchrony was present in 36% of Group 1 patients, in 58% of Group 2 patients, and in 79% of Group 3 patients (P < 0.000). Linear regression demonstrated a weak relation between QRS and intraventricular dyssynchrony. A greater proportion of patients with interventricular dyssynchrony was observed in Group 3 or Group 2 compared to patients with normal QRS duration (32% in Group 1 vs. 51.5% in Group 2 vs. 76.5% in Group 3, P < 0.000). Linear regression demonstrated a significant relation between QRS duration and interventricular mechanical delay.
Conclusions:

Although both interventricular and intraventricular dyssynchrony increased with the increasing QRS duration, the correlation between intraventricular mechanical and electrical dyssynchrony was weak. The lack of intraventricular dyssynchrony in a fraction of patients with standard CRT indication by QRS duration may provide us insight into the nonresponders rates.
Investigation of Various Types of Neurocardiogenic Response to Head‐Up Tilting by Extended Hemodynamic and Neurohumoral Monitoring
Authors: NOWAK LORENZ , NOWAK FRANZ G. , JANKO SABINE , DORWARTH UWE , HOFFMANN ELLEN , BOTZENHARDT FLORIAN 
Published: May 2007

Background:

The pathophysiology of neurocardiogenic syncope is heterogeneous. This study aim was to analyze whether extended monitoring during tilt‐table testing provided additional information on the hemodynamic and vegetative state prior to neurocardiogenic syncope.
Methods:

This retrospective analysis is based on data of head‐up tilt‐table testing of 40 unselected consecutive patients with a history of unexplained syncope. For optimized characterization of the type of syncope, monitoring included electrocardiogram (ECG), blood pressure measurements and cardiac output, peripheral vascular resistance and contractility index measurements by impedance cardiography, as well as epinephrine and norepinephrine plasma levels in supine position and every 5 min during tilting.
Results:

Seven of 40 patients were unsuitable for analysis because of incomplete data sets. Tilt‐table was positive in 26 patients, negative in 7. Groups did not differ in hemodynamic and catecholaminergic parameters at baseline. Responses to tilting were VASIS 1 (mix of cardioinhibitory and vasodepressor) in 5 patients, VASIS 2B (cardioinhibitory with asystole >3sec) in 3, VASIS 3 (vasodepressor) in 16, orthostatic dysregulation in 2. In VASIS 1, the catecholamine measurement 4 min before syncope showed a proportionally larger increase of the epinephrine level than of norepinephrine. This disproportion was not observed in VASIS 2B and 3. In VASIS 2B, strong vasoconstriction and negative inotropy were evident in the presyncopal period. In VASIS 3, vascular resistance decreased continuously before syncope, while contractility index increased inadequately. Presyncopal epinephrine surge or norepinephrine loss was not observed in this group, suspecting other vasodilating factors.
Conclusions:

Extended monitoring by impedance cardiography and plasma catecholamine measurements during tilt‐table testing gave further insight into different hemodynamic and neurohumoral presyncopal patterns among the various types of neurocardiogenic syncope and may thereby help to develop individualized therapeutic concepts.
Effects of Intracoronary Low‐Dose Enalaprilat on Ventricular Repolarization Dynamics After Direct Percutaneous Intervention for Acute Myocardial Infarction
Authors: BONNEMEIER HENDRIK , SCHÄFER ULRICH , KURZ THOMAS , ORTAK JASMIN , HARTMANN FRANZ , KATUS HUGO A. , RICHARDT GERT , SCHUNKERT HERIBERT 
Published: May 2007

Background:

Data from animal models suggest that inhibition of angiotensin converting enzymes result in an increased ventricular electrical stability after reperfusion in acute myocardial infarction (MI). As electrical stability is largely dependent on ventricular repolarization, we sought to determine the impact of low‐dose intracoronary (ic.) application of enalaprilat (EN) as an adjunct to direct primary coronary intervention (PCI) on QT dynamics in the acute phase of MI.
Methods:

Twenty‐two consecutive patients with a first acute MI who underwent successful direct PCI (TIMI 3 flow) were randomized to ic. EN (50 μg) or placebo/saline (PL), given immediately after reopening of the infarct vessel. On hospital admission, a 24‐hour‐Holter‐electrocardiogram (ECG) was initiated. Slopes of the linear QT/RR regression were determined for the time intervals before reperfusion and after reperfusion.
Results:

A total of 7 patients in the EN group and 8 patients in the PL group had valid ECG recordings for beat‐to‐beat QT analysis. Mean RR interval and mean QT interval were not significantly different between the EN and the PL groups both before and after PCI. There were also no significant differences regarding QT/RR slopes between EN and PL groups before PCI. After PCI, QT/RR slopes significantly decreased in the EN group (0.169 ± 0.04 to 0.121 ± 0.03; P < 0.01), whereas there were no significant alterations in the PL group (0.175 ± 0.04 to 0.171 ± 0.03; P = ns).
Conclusions:

Intracoronary EN therapy as an adjunct to direct PCI significantly decreases QT/RR slopes, suggesting a normalization of the coupling between heart rate and repolarization by improving electrical restitution. Thus, our findings offer new insights into possible beneficial effects of ACE inhibition on cardiac electrical stability in acute MI.
Is Home Orthostatic Self‐Training Effective in Preventing Neurally Mediated Syncope?
Authors: ON YOUNG KEUN , PARK JUNGWAE , HUH JUNE , SOO KIM JUNE 
Published: May 2007

Background:

Repeated orthostatic stress may prove to be of benefit in the regulation of neurally mediated syncope. But the role of home orthostatic self‐training is not established to prevent symptoms in patients with neurally mediated syncope. We performed a prospective and randomized study to evaluate the effectiveness of repeated home orthostatic self‐training in preventing tilt‐induced neurally mediated syncope.
Methods and Results:

Fourty‐two consecutive patients (24 males and 18 females, mean age 39 years, 16–68 years) with recurrent neurally mediated syncope were randomized into the tilt training and control groups. The home orthostatic self‐training program consisted of daily sessions for 7 days a week for 4 weeks. In order to determine the effects of home orthostatic self‐training, we repeated the head‐up tilt test in both groups 4 weeks later. Among the tilt‐training group, 9 of 16 patients (56%) had a positive response on follow‐up head‐up tilt test. Among the untreated control group, 9 of 17 patients (53%) had a positive response on follow‐up head‐up tilt test. In subgroup analyses according to the number of tilt‐training sessions or the classified type, we found no differences in the follow‐up head‐up tilt test responses. Spontaneous syncope or presyncope over mean follow‐up of 16.9 months were observed in 42.9% versus 47.1% in the tilt‐training and control group, respectively.
Conclusions:

Home orthostatic self‐training was ineffective in reducing the positive response rate of head‐up tilt test in patients with recurrent neurally mediated syncope.
Determinants of Lesion Sizes and Tissue Temperatures During Catheter Cryoablation
Authors: WOOD MARK A. , PARVEZ BABAR , ELLENBOGEN AMY L. , SHAFFER KATHERINE M. , GOLDBERG SCOTT M. , GASPAR MICHAEL P. , ARIEF ISTI , SCHUBERT CHRISTINE M. 
Published: May 2007

Background:

Factors which influence lesion size from catheter‐based cryoablation have not been well described. This study describes factors which influence lesion size during catheter cryoablation.
Methods and Results:

Cryoablation was delivered to porcine left ventricular myocardium in a saline bath using 4‐ or 8‐mm electrode catheters. Ablation was delivered with the electrodes either vertical or horizontal to the tissue and both with and without superfusate flow over the electrode. The effect of electrode contact pressure was tested. Lesion dimensions were measured. All experiments were duplicated to measure tissue temperatures at 1‐, 2‐, 3‐, and 5‐mm deep to the ablation electrode. The 8‐mm electrode produced lower tissue temperatures and larger lesion volumes when compared with the 4‐mm electrode (all P < 0.05). Superfusate flow slowed the rate of tissue cooling, markedly warmed tissue temperatures, and reduced lesion volume when compared with no flow conditions. By linear regression modeling, lesion sizes and tissue temperatures were related to the presence of superfusate flow, electrode orientation, contact pressure and electrode size, or catheter refrigerant flow rate (r2 for models = 0.90–0.96, all P < 0.001). Electrode temperature predicted lesion size or tissue temperatures only when analyzed independent of electrode size or refrigerant flow rate.
Conclusions:

Lesion sizes and tissue temperatures during catheter cryoablation are related to convective warming, electrode orientation, electrode contact pressure, and any of the following: electrode size, catheter refrigerant flow rate or electrode temperature. However, electrode temperature may be a poor predictor of lesion size and tissue temperature for a given catheter size.
Incidence and Initial Characteristics of Pilsicainide‐Induced Ventricular Arrhythmias in Patients With Brugada Syndrome
Authors: CHINUSHI MASAOMI , KOMURA SATORU , IZUMI DAISUKE , FURUSHIMA HIROSHI , TANABE YASUTAKA , WASHIZUKA TAKASHI , AIZAWA YOSHIFUSA 
Published: May 2007

Background: In patients with Brugada syndrome, class I antiarrhythmic drugs can trigger ventricular arrhythmias (VA). The incidence and initial characteristics of VA that developed after pilsicainide was examined in 28 patients with Brugada‐type electrocardiographic (ECG) abnormalities and with a positive response in the pilsicainide test. The clinical outcome was also compared between patients with and without pilsicainide‐induced VA.
Methods and Results: In all patients, pilsicainide increased ST segment elevation and accentuated type 1 ECG changes. Ventricular tachycardia (VT) developed in 3 patients and premature ventricular complexes (PVC) in 2 other patients. These 5 patients (group I) had higher ST segment elevation in lead V2 on the ECG at baseline and after pilsicainide and showed a longer QTc interval after pilsicainide than the other 23 patients (group II). However, there was no difference between the 2 groups regarding incidence of prior cardiac events, results of signal‐averaged ECG, HV interval, inducibility of ventricular fibrillation by programmed electrical stimulation, or QRS duration. In 1 patient, PVC originated from 3 sites, 2 of which triggered polymorphic VT. The right ventricular (RV) outflow tract was the origin of 2 types of PVC, and other RV sites of 5 other types. During a 45 ± 37 months follow‐up, polymorphic VT recurred in 2 patients in group II.
Conclusions: Pilsicainide induced VA in some patients with Brugada syndrome, but this result may not be used as a parameter of the risk stratification of Brugada syndrome. Multiple PVC induced by pilsicainide and triggering polymorphic VT originated from several RV sites is an important factor when considering patients for treatment with catheter ablation.
Feasibility of Percutaneous Coronary Interventions in Early Postcoronary Artery Bypass Graft Occlusion or Stenosis
Authors: ABDULMALIK AMEEN , ARABI ABDULRAHMAN , ALROAINI ABDULWAHHAB , ROSMAN HOWARD , LALONDE THOMAS 
Published: May 2007

Background: With continuing technical advances in percutaneous coronary interventions (PCI) for coronary artery disease (CAD), patients undergoing coronary artery bypass surgery (CABG) often have complex coronary anatomy that is not ideal for PCI. Because of the complex anatomy, these patients have a higher risk of early graft occlusion. The feasibility of PCI in the treatment of early graft occlusion is not well established.
Methods: A retrospective chart review was performed of patients presenting with recurrent ischemia within three months post‐CABG and at one‐year follow‐up.
Results: Forty‐six patients with 156 grafts were identified. Three presented with STEMI, 21 with NSTEMI, 21 with unstable angina, and one with congestive heart failure. Sixty‐three grafts were occluded or stenosed (>70%). Twenty‐seven grafts (43%) in 17 patients were not amenable to PCI. The other 34 grafts (54%) in 23 patients underwent successful PCI. PCI was performed upon native vessels and occluded grafts with equal frequency. Six patients had patent grafts. At one‐year follow‐up, six of 23 patients in the PCI group were readmitted with ischemia; five vessels (14%) in four patients had restenosed. There were no deaths. In the group with no PCI, 11 of 23 patients were readmitted with ischemia with one death.
Conclusion: PCI for early post‐CABG occlusion was safely performed in slightly more than half of target vessels. PCI was performed upon native vessels and occluded grafts with equal frequency. After initial PCI success, the clinical target vessel restenosis rate was 14% at one‐year follow‐up.
Spatial clustering of Diabrotica virgifera virgifera and Agriotes ustulatus in small‐scale maize fields without topographic relief drift
Authors: Toepfer Stefan , Ellsbury Michael M. , Eschen René , Kuhlmann Ulrich 
Published: May 2007

AbstractThe soil‐living larvae of Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) and Agriotes ustulatus Schaller (Coleoptera: Elateridae) can cause economic damage to maize roots, Zea mays L. (Poaceae). This study investigated the spatial clustering of both pests in four small‐scale maize fields in southern Hungary, where clustering had been observed but not expected due to the lack of topographic relief drifts and soil structuring. Between 2000 and 2002, numbers of D. v. virgifera larvae and adults and of A. ustulatus larvae were determined at four randomly chosen georeferenced maize plants in each of 24 plots per field. Soil moisture, soil bulk density, and vegetational characteristics were assessed. Moran's I test for spatial autocorrelations, semivariogram analyses, and interpolated mapping revealed that D. v. virgifera larvae and adults were spatially clustered in 67 and 50% of cases, respectively. Larvae of A. ustulatus were clustered in 75% of cases. Diabrotica virgifera virgifera larval distributions were mainly determined by increasing weed density (negative correlation), in particular with high densities of Cirsium arvense (L.) (Asteraceae), as well as by increasing soil moisture (negative correlation). Adult distributions of D. v. virgifera were mainly determined by the density distribution of flowering maize. They were moreover correlated with larval distribution and with the adult distribution of the previous year. The density distributions of male adults differed from those of females. Female density was additionally correlated with higher soil moisture and Poaceae density, e.g., with Sorghum halepense (L.) Pers. No relation was found between the larvae of A. ustulatus and D. v. virgifera. Agriotes ustulatus larval distributions were mainly determined by vegetational cover (correlation with less cover). Conclusively, male and female D. v. virgifera adults, larvae of D. v. virgifera, and larvae of A. ustulatus will display different spatial clustering even within ostensibly homogeneous habitats of flat small‐scale maize fields.
First field evidence that parasitoids use upwind anemotaxis for host‐habitat location
Authors: Williams Ingrid H. , Frearson David J.T. , Barari Hassan , McCartney Alastair 
Published: May 2007

AbstractThe direction of flight of natural populations of Phradis interstitialis (Thomson), Tersilochus obscurator Aubert (both Hymenoptera: Ichneumonidae), and Platygaster subuliformis (Kieffer) (Hymenoptera: Platygastridae), parasitoids of three crucifer‐specialist herbivores, to and from their hosts’ host plant [oilseed rape, Brassica napus L. (Brassicaceae)] was studied in the field within a heterogeneous arable environment. Double‐sided Malaise traps encircling a plot of winter oilseed rape (cultivar Lutin) were used to sample the parasitoids as they flew towards and away from the plot during spring and summer. Daily trap catch of parasitoids and trap air flow were compared using Spearman's rank correlation. For all 14 insect days analysed, and for each species, the correlations between daily catch of parasitoids into distal halves of traps (relative to the plot) and wind direction were negative, significantly so on half the days analysed. This confirmed that flights towards the plot were by upwind anemotaxis. In contrast, the correlations between daily catch of parasitoids into proximal halves of traps (relative to the plot) and wind direction were most often crosswind; they were never strongly nor significantly either negative or positive. Implications of the results for integrated pest management strategies incorporating biological control with these parasitoids are discussed.
Anti‐inflammatory efficacy of a single posterior subtenon injection of triamcinolone acetonide versus prednisolone acetate 1% eyedrops after pars plana vitrectomy
Authors: Paccola Letícia , Jorge Rodrigo , Barbosa José C. , Costa Rogério A. , Scott Ingrid U. 
Published: May 2007

AbstractPurpose:  To compare the safety and anti‐inflammatory efficacy of a single posterior subtenon injection of triamcinolone acetonide (TA) with prednisolone acetate 1% eyedrops after pars plana vitrectomy (PPV).Methods:  The study included 40 consecutive phakic eyes of 40 patients undergoing PPV for non‐clearing vitreous haemorrhage with attached retina (verified by echography), epiretinal membrane or macular hole. At the end of the surgical procedure, eyes were randomized to receive either a single posterior subtenon injection of TA (40 mg in 1 ml) plus sham eyedrops (prednisolone acetate 1% vehicle) postoperatively (group TA), or a posterior subtenon sham injection (1 ml balanced salt solution) plus prednisolone acetate 1% eyedrops postoperatively (group ED).Results:  There was no difference in the severity of anterior chamber cell and flare between the two groups at any time‐point during the study period (p > 0.05). Separate within‐group analysis revealed a significant decrease in anterior chamber cell and flare from postoperative day 1 to postoperative days 7, 14 and 28 in both groups (p < 0.05). There was no difference in pain, photophobia, conjunctival erythema, ciliary flush or chemosis scores between the two groups at any time‐point during the study period (p > 0.05). Steroid‐induced intraocular hypertension was not observed in either group.Conclusions:  A single posterior subtenon injection of TA can be as effective and safe as a 4‐week regimen of prednisolone acetate 1% eyedrops in controlling intraocular inflammation after PPV.
Full‐thickness macular hole in a patient with diabetic cystoid macular oedema treated by intravitreal triamcinolone injections
Authors: Lecleire‐Collet Amélie , Offret Olivier , Gaucher David , Audren François , Haouchine Belkacem , Massin Pascale 
Published: May 2007

Abstract.Purpose:  Full‐thickness macular hole associated with diabetic macular oedema is a rare feature and its pathogenesis remains incompletely elucidated. We report the occurrence of a full‐thickness macular hole, documented with optical coherence tomography (OCT), in a patient with diabetic cystoid macular oedema treated by intravitreal triamcinolone injections.Case Report:  A 48‐year‐old woman with refractory diabetic cystoid macular oedema underwent successive intravitreal triamcinolone injections, which were followed by a progressive thinning of the neurosensory retina at the fovea, and then by a full‐thickness macular hole, associated with a perifoveal posterior hyaloid detachment, visible on OCT. During pars plana vitrectomy, a thin epiretinal macular membrane was diagnosed and removed.Discussion:  Pathogenesis of the present full‐thickness macular hole associated with diabetic macular oedema is different from that of idiopathic macular holes because anteroposterior vitreous tractions were not involved in its formation. Recurrent intravitreal triamcinolone injections may have had an indirect role in the development of the macular hole, by favouring the rupture of distended Muller cells and intraretinal pseudocysts.
Entry‐site‐related retinal detachment after pars plana vitrectomy
Authors: Wimpissinger Barbara , Binder Susanne 
Published: May 2007

Abstract.Purpose:  Today, pars plana vitrectomy represents a standard surgical procedure for a number of retinal diseases that were previously considered inoperable. The aim of the present study is to investigate the entry site of pars plana vitrectomy as a possible source of retinal detachment.Methods:  We reviewed retrospectively all cases of uncomplicated pars plana vitectomies because of macular hole, macular pucker and diabetic macular oedema performed in our department between 1 January 2001 and 7 July 2004.Results:  Over 3.5 years, 244 pars plana vitrectomies because of macular disease were performed. Sclerotomy‐related retinal detachment was observed in 11 (4.5%) cases. These retinal detachments occurred at a mean of 37 (2–100) days after surgery. They appeared within the first 4 weeks in 55% of the cases.Conclusion:  Iatrogenic retinal breaks and detachment continue to be a severe complication of pars plana vitrectomy, despite improvements in instrumentation and surgical techniques. A 4.5% incidence of sclerotomy‐related retinal detachment after simple vitrectomy calls for action. Current approaches to reduce this complication – such as circular peripheral cryoretinopexy, scleral buckling or 360° laser treatment – are invasive. We recommend extended vitreous base cleaning with scleral indentation and examination of the entry sites, performed with a three‐mirror lens or via careful indirect ophthalmoscopy into the periphery, 4 weeks after surgery.