bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Prospective Randomized Evaluation of VV Delay Optimization in CRT‐D Recipients: Echocardiographic Observations from the RHYTHM II ICD Study
Authors: BORIANI GIUSEPPE , BIFFI MAURO , MÜLLER CORD PAUL , SEIDL KARL‐HEINZ , GROVE RAINER , VOGT JÜRGEN , DANSCHEL WILFRIED , SCHUCHERT ANDREAS , DEHARO JEAN‐CLAUDE , BECKER THORSTEN , BOULOGNE ERIC , TRAPPE HANS JOACHIM ,   for the Resynchronization for the HemodYnamic Treatment for Heart Failure Management II (RHYTHM II) Investigators
Published: February 2009

Background: All current cardiac resynchronization therapy (CRT) devices allow the programming of the atrioventricular (AV/PV) delays and the sequential stimulation of the ventricles via the inter ventricular (VV) delay.
Aim: This post hoc analysis of the RHYTHM II study was conducted to compare the reverse remodeling associated with VV delay optimization in patients randomly assigned to simultaneous (SIM) biventricular stimulation versus patients assigned to optimized VV delay programming (OPT) (1:3 randomization scheme).
Methods: The analysis included 14 patients assigned to the SIM group and 34 patients to the OPT group who completed the 6‐month follow‐up period with paired echocardiographic recordings.
Results: In both study groups, changes consistent with left ventricular (LV) remodeling were observed between baseline and 6 months, with significant improvements in LV function and decrease in LV dimensions. In the OPT group, there was also a decrease in left atrial diameter and mitral valve closure to opening time. At 6 months, the overall proportion of echocardiographic responders (≥10% decrease in LV end‐systolic volume or ≥5% absolute increase in LV ejection fraction) was similar in both groups. The optimal AV/VV delays, evaluated by maximization of LV outflow tract velocity time integral, changed over time.
Conclusions: Ventriculo‐ventricular delay optimization was associated with better immediate hemodynamic function than simultaneous biventricular stimulation, though did not promote additional reverse remodeling at 6 months and did not increase the proportion of echocardiographic responders to CRT. Optimization of both the AV and VV intervals was patient‐specific and optimal values changed over time.
Implantable Cardioverter Defibrillator Therapy for Primary Prevention of Sudden Cardiac Death after Myocardial Infarction:
Authors: FOLEY PAUL W.X. , ADDISON CLARA E. , WHINNEY STEPHANIE B. , PATEL KIRAN , CUNNINGHAM DAVID , FRENNEAUX MICHAEL P. , LEYVA FRANCISCO 
Published: February 2009

Study Objective: To estimate the proportion of patients eligible for implantable cardioverter defibrillator (ICD) therapy for the primary prevention of sudden cardiac death after a myocardial infarction (MI), according to the current guidelines.
Methods: Eligibility was assessed retrospectively at 6 weeks in 513 post‐MI survivors (age 66 ± 13 years, left ventricular ejection fraction 48.2 ± 17%) on the basis of an electrocardiogram and an echocardiogram.
Results: LVEF was ≤ 40% in 37% and ≤ 35% in 30%, and QRS duration was <120 ms in 89% and ≥120 ms in 11% of patients. The proportion of post‐MI patients meeting the criteria set by guidelines were 37% for 2006 American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) 26.5% for 2008 ACC/AHA/Canadian Heart Rhythm Society 16.3% for 2005 US Centers for Medicare and Medicaid Services (CMS), and 5.8% for the 2006 United Kingdom (UK) National Institute of Clinical Excellence (NICE). According to 2005 CMS and 2006 UK‐NICE guidelines, Holter monitoring was required in 7% and 18%, respectively. For the United States (700,000 MI in 2006), the 2006 ACC/AHA/ESC guidelines equate to 216,783 ICD implantations/year. For UK (60,499 MI in 2006), the 2006 NICE guidelines equate to 2,941 ICD implantations, 10,488 Holter studies, and 1,065 VT induction tests/year.
Conclusions: Current ICD therapy guidelines for primary prevention of SCD post‐MI demand a substantial increase in service provision worldwide.
Tricuspid Incompetence Following Permanent Pacemaker Implantation
Authors: KLUTSTEIN MARC , BALKIN JONATHAN , BUTNARU ADI , ILAN MICHAEL , LAHAD AMNON , ROSENMANN DAVID 
Published: February 2009

Aim: Severe tricuspid insufficiency (TI) after permanent pacemaker implantation (PPI) has been described in small series of patients, though its incidence is not known.
Methods: We retrospectively analyzed the data of 545 patients who underwent PPI and had Doppler echocardiograms performed before and after the procedure. We excluded 135 patients who had ≥moderate TI on the 1st Doppler echocardiogram.
Results: Group 1 included 75 patients (18.3%) who had a >2 grades worsening of TI, and group 2 included 335 patients (82%) with <2 grade increase in TI after PPI. Patients in group 1 were 77 ± 7 years of age, versus 72 ± 10 years in group 2 (P < 0.001). There was no difference in left ventricular size and function. The TI gradient before PPI was higher in group 2 (25 ± 13 mmHg versus 19 ± 12 mmHg [P < 0.001]), though within the normal range in both groups. The mitral E/A ratio was 0.98 in group 1 versus 1.42 in group 2 (P < 0.001). The systolic TI gradient after implantation was 42 ± 12 mmHg in group 1, versus 33 ± 8 mmHg in group 2 (P < 0.001).
Conclusion: Worsening of TI after PPI was not rare and was observed more often in older patients, with abnormal LV relaxation and who developed pulmonary hypertension after the procedure.
Long‐Term Outcomes of CRT‐PM Versus CRT‐D Recipients
Authors: STABILE GIUSEPPE , SOLIMENE FRANCESCO , BERTAGLIA EMANUELE , ROCCA VINCENZO LA , ACCOGLI MICHELE , SCACCIA ALBERTO , MARRAZZO NATALE , ZOPPO FRANCO , TURCO PIETRO , IULIANO ASSUNTA , SHOPOVA GERGANA , CIARDIELLO CARMINE , DE SIMONE ANTONIO 
Published: February 2009

Objective: To compare the rates of all‐cause mortality in recipients of cardiac resynchronization therapy devices without (CRT‐PM) versus with defibrillator (CRT‐D).
Methods: Between February 1999 and July 2004, 233 patients (mean age = 69 ± 8 years, 180 men) underwent implantation of CRT‐PM or CRT‐D devices. New York Heart Association (NYHA) heart failure functional class II was present in 11%, class III in 69%, and class IV in 20% of patients; mean left ventricle ejection fraction (LVEF) was 26.5 ± 6.5 %, 48% presented with idiopathic dilated cardiomyopathy and 49% with ischemic heart disease. Cox multiple variable regression analysis was performed in search of predictors of death.
Results: The clinical characteristics of the 117 CRT‐PM and 116 CRT‐D recipients were similar, except for LVEF (28.2 ± 6.2% vs 25.0 ± 6.5%, respectively; P < 0.001), and ischemic versus nonischemic etiology of heart failure (41% vs 56%, respectively P = 0.02). Over a mean follow‐up of 58 ± 15 months, no significance difference in overall mortality rate was observed between the two study groups. Male sex, NYHA functional class IV, and atrial fibrillation at implant were significant predictors of death.
Conclusions: There was no difference in long‐term survival rate among patients with CRT‐D versus CRT‐PM, although CRT‐D more effectively lowered the sudden death rate. Male sex, NYHA functional class IV, and atrial fibrillation predicted the worst prognosis.
Long‐Term Changes in High‐Voltage Impedance of Defibrillating Leads
Authors: VAL‐MEJIAS JESUS E. , JANET DAMIEN R. , RAMADAS SUMATI 
Published: February 2009

Background: The maturation of the high‐voltage impedance (HVLI) of defibrillating leads has not been explored thoroughly. Since impedance influences the charge, current, and energy delivered to the heart in both fixed pulse‐width and fixed tilt implantable cardioverter‐defibrillator (ICD) waveforms, changes in HVLI might have an effect on the defibrillation threshold. This analysis examined the maturation of defibrillation lead HVLI.
Methods: The data were collected in 515 recipients of ICDs capable of storing high‐voltage shock diagnostics, including HVLI. Data with constant superior vena cava (SVC) coil configuration (coil ON or OFF) were collected for up to 24 months. HVLI values were recorded, plotted, and normalized by the value at implant; the percentage of patients in whom HVLI increased or decreased by ≥6 Ω was calculated, and the maturation of leads with SVC ON versus OFF was compared.
Results: A ≥6 Ω increase or decrease in HVLI was observed in 41% of patients more than 3 months after ICD implant, with the magnitudes as follows: 6–7.5 Ω change = 16%, 8–9.5 Ω= 11%, 10–11.5 Ω= 6%, and ≥12 Ω= 8%. In this subgroup, 67% of patients showed an increase in impedance, and the remaining 33% of patients showed a decrease. For ICD‐programmed SVC OFF, the right ventricular (RV) Coil‐to‐Can HVLI increased by 8 Ω after 6 weeks and did not significantly change thereafter.
Conclusions: HVLI changed significantly in 41% of leads after 3 months. The HVLI trend of the RV Coil‐to‐Can configuration appeared to be similar to the SVC Coil/Can‐to‐RV and Coil‐to‐Can configurations. Changes in HVLI of 6–12 Ω will alter the characteristics of the shock waveform and could require retuning of the waveforms to maintain adequate DFT safety margin. If re‐tuning the shock waveforms is not performed, these HVLI changes have the potential to result in elevated DFT. These HVLI changes may partially account for the 15% increase in DFT over time reported in the literature.
T‐Wave Variability as a Risk Stratifier in Patients with Dilated Cardiomyopathy
Authors: TASIČ JERNEJA , ZUPAN IGOR 
Published: February 2009

Background: T‐wave alternans is an important identifier of patients at risk of sudden cardiac death (SCD), but the procedure usually requires stress testing. In this study, the variability of T‐wave amplitude (TVAR) was evaluated at rest, as a risk stratifier for SCD.
Methods: This study included 57 patients in sinus rhythm and with a left ventricular ejection fraction ≤40%, of whom 34 (60%) received an implantable cardioverter‐defibrillator (ICD) after surviving SCD, and 23 (40%) presented with ischemic or nonischemic cardiomyopathy and no history of SCD. A 20‐minute high‐resolution electrocardiographic recording for TVAR assessment was performed during supine rest. The vector magnitude was used as a primary lead for TVAR analysis.
Results: The mean, median, and maximum (max) values of TVAR were measured. The patients with ICD had a lower max TVAR than the patients without ICD (67 vs 95 μV; P = 0.045), though the mean and median TVAR values were similar. By multivariate logistic analysis, max TVAR remained a predictor of SCD, after adjustments for potentially confounding factors (P = 0.044).
Conclusion: Max TVAR was a predictor of arrhythmic events in patients with dilated cardiomyopathy at rest.
Evaluation of Sinus and Atrioventricular Nodes Function in Patients with Vasovagal Syncope
Authors: PIETRUCHA ARTUR Z. , WNUK MATEUSZ , WOJEWÓDKA‐ŻAK EWA , WĘGRZYNOWSKA MARTA , MROCZEK‐CZERNECKA DANUTA , BZUKAŁA IRENA , KONDURACKA EWA , PIWOWARSKA WIESŁAWA 
Published: February 2009

Aim: Evaluation of sinus and atrioventricular nodes function as a potential factor responsible for prolonged bradycardia, asystole, or both in patients with cardioinhibitory and non‐cardioinhibitory vasovagal syncope (VVS). The study included 258 patients (mean age = 47.7 ± 17.2 years; range 18–62; 147 females) with a history of VVS. They were divided among four groups, according to results of head‐up tilt test (HUTT).
Methods: All patients underwent standard HUTT, carotid sinus massage (CSM), and rapid transesophageal atrial pacing for evaluation of total sinus node recovery time (SNRT), and corrected sinus node recovery time (CNRT), resting and intrinsic heart rate (IHR), and Wenckebach point (WP). Values of SNRT > 1,500 ms, CNRT > 525 ms, WP < 130 bpm, and CSM‐induced pause >3 seconds were considered abnormal.
Results: SNRT, CNRT, and WP before and after pharmacological blockade, resting heart rate, and IHR did not differ significantly among the study groups. The prevalence of mild sinus node dysfunction (SND), decreased value of WP, and cardioinhibitory carotid sinus hypersensitivity was similar among all study groups.
Conclusions: The prevalence of mild SND, abnormal atrioventricular conduction, and carotid sinus hypersensitivity (CSH) was similar among patients with VVS regardless of the type of vasovagal reaction. SND and CSH do not seem to play an important role in the pathogenesis of cardioinhibitory vasovagal reaction.
Early Experience with Robotic Navigation for Catheter Ablation of Paroxysmal Atrial Fibrillation
Authors: KAUTZNER JOSEF , PEICHL PETR , ČIHÁK ROBERT , WICHTERLE DAN , MLČOCHOVÁ HANKA 
Published: February 2009

Introduction: Pulmonary venous antra isolation (PVAI) is the cornerstone of catheter ablation procedure for drug refractory paroxysmal atrial fibrillation (AF). However, the procedure is technically challenging. Robotic navigation has a potential to expedite and facilitate the procedure.
Methods: A robotic catheter control system was used for remote navigation‐supported PVAI in 22 patients (mean age = 55 ± 9 years, 16 males, study group). An irrigated‐tip catheter with estimate of catheter force on the tissue was used. This was compared in nonrandomized fashion with conventional hand‐controlled catheter ablation in 16 patients (mean age = 55 ± 9 years, 13 males, control group). The procedures were performed under guidance of Ensite NavX navigation system (St. Jude Medical, St. Paul, MN, USA) and intracardiac echocardiography.
Results: Robotic navigation was associated with significantly shorter overall duration of radiofrequency delivery (1,641 ± 609 vs 2,188 ± 865 seconds, P < 0.01), shorter total procedural time (207 ± 29 vs 250 ± 62 minutes, P = 0.007), fluoroscopy exposure (15 ± 5 vs 27 ± 9 minutes, P < 0.001), and lower radiation dose (1,119 ± 596 vs 3,048 ± 2,029 mGy/m2, P < 0.001). No complication was observed in either the study or the control group. During the 5 ± 1 months follow‐up in the study group and 9 ± 3 months in the control group, 91% and 81% of patients, respectively, were AF free.
Conclusions: In our early clinical experience, PVAI using a remote robotic catheter navigation was effective, safe, and associated with shorter procedural and fluoroscopic times than conventional PVAI.
Effect of Right Ventricular Apical Pacing in Survivors of Myocardial Infarction
Authors: MUTO CARMINE , ASCIONE LUIGI , CANCIELLO MICHELANGELO , CARRERAS GIOVANNI , IENGO RAFFAELE , OTTAVIANO LUCA , CALVANESE RAIMONDO , ACCADIA MARIA , CELENTANO EDUARDO , CIARDIELLO CARMINE , TUCCILLO BERNARDINO 
Published: February 2009

Background: Much information is available regarding the possible negative effects of long‐term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).
Methods and Results: We screened 115 consecutive post‐MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow‐up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 ± 10 to 39 ± 11 (P < 0.01), and a minimal change in the unpaced group, from 57 ± 8 to 56 ± 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.
Conclusions: The study showed that, in post‐MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.
Low Referral Rate for Prophylactic Implantation of Cardioverter‐Defibrillators in a Tertiary Care Medical Center
Authors: BRADFIELD JASON , WARNER ALBERTA , BERSOHN MALCOLM M. 
Published: February 2009

Background: Implantable cardioverter‐defibrillators (ICDs) for primary prevention became standard of care after the publication of the second Multicenter Automatic Defibrillator Implantation Trial (MADIT‐II) and Sudden Cardiac Death in Heart Failure Trial (SCD‐HeFT).
Objective: To determine the percentage of patients in a Veterans Affairs medical center appropriately referred for primary prophylaxis ICD and to further categorize the reasons patients are not being referred.
Methods

: Echocardiograms obtained since the release of MADIT‐II in 2002 were searched for a left ventricular ejection fraction (LVEF) ≤ 35% and ≤30%. We randomly selected 120 patients per year from 2002 to 2006, for a total of 600 patients in each group. Data were reviewed to determine the number of ICD recipients and the reasons patients were not referred.
Results: In the LVEF ≤ 35% group an ICD was implanted in 28% of 392 eligible patients. Nonreferral (58%) was the most common reason that eligible patients did not receive an ICD. Patients were not referred for ICD because of appropriate contraindications in 26% of cases. Overall mortality was 29% (15% with and 31% without ICD). In the LVEF ≤30% group an ICD was implanted in 33% of 388 eligible patients. Nonreferral (51%) was the most common reason that eligible patients did not receive an ICD. Patients were not referred for ICD because of appropriate contraindications in 24% of cases. Overall mortality was 28% (18% with and 32% without ICD).
Conclusions: After the publication of MADIT‐II and SCD‐HeFT, only 42% of eligible patients with LVEF ≤ 35% and 49% of patients with LVEF ≤30% were offered a potentially life‐saving ICD between 2002 and 2006 in our medical center, sometimes with considerable delay.
Spatial Relationships between the Pulmonary Veins and Sites of Complex Fractionated Atrial Electrograms During Atrial Fibrillation
Authors: CHEN JIAN , OFF MORTEN KRISTIAN , SOLHEIM EIVIND , HOFF PER IVAR , SCHUSTER PETER , OHM OLE‐JØRGEN 
Published: February 2009

Background: Pulmonary vein (PV) isolation is used for the treatment of atrial fibrillation (AF). Complex fractionated atrial electrogram (CFAE) mapping has been introduced to guide AF ablation. However, the spatial relationship between PV and CFAE is not well defined.
Methods and Results: The study included 21 patients (mean age 57 ± 11 years, 17 men, 14 paroxysmal, two persistent, and five long‐standing persistent AF) referred for PV isolation. Electrograms were sampled for 8 seconds at each site during stable AF (13 induced). High‐frequency was defined as <80 ms of CFAE value. The distance between CFAE and the nearest PV ostium was measured. The PV ostia and antra were demarcated by fluoroscopy guidance and endocardial reconstruction. Among 82 PV mapped (left common four, superior 17, inferior 17; right superior 21, inferior 21, middle 2), 52.4% and 25.6% of high‐frequency CFAE were located on the anterior and posterior walls, respectively, inside the PV or at the ostium. No high‐frequency CFAE was observed in two out of 60 and one out of 20 PV anteriorly, versus seven out of 60 and 11 out of 20 PV (P < 0.001) posteriorly, in paroxysmal and persistent AF, respectively. In the PV with high‐frequency CFAE, the mean shortest distances to the PV ostia in paroxysmal versus persistent AF were 2.7 ± 5.1 versus 7.4 ± 5.4 mm anteriorly (P < 0.01), and 6.5 ± 6.4 versus 9.4 ± 8.4 mm posteriorly (ns).
Conclusions: During PV isolation, extending the ablation lesions by up to 10 mm from the PV ostia might cover most high‐frequency CFAE around the PV antra. High‐frequency CFAE were more often located in the PV ostia in paroxysmal than in persistent AF.
Initial Experience with Catheter Ablation Using Remote Magnetic Navigation in Adults with Complex Congenital Heart Disease and in Small Children
Authors: SCHWAGTEN BRUNO , JORDAENS LUC , WITSENBURG MARTIN , DUPLESSIS FREDERIK , THORNTON ANDREW , VAN BELLE YVES , SZILI‐TOROK TAMAS 
Published: February 2009

Background: The improved outcomes and increased availability of surgery for congenital heart disease (CHD) over the last three decades have created a small but steadily increasing subset of patients with unique needs: children and adults with complex arrhythmias in the setting of structural cardiac abnormalities. Radiofrequency catheter ablation (RFCA) in these patients, and in small children with normal cardiac anatomy, is effective but challenging. An understanding of specific anatomical and electrophysiological characteristics of these patients and the technical challenges in addressing them are critical to the success of this therapy. Tools specifically designed for intracardiac diagnosis and therapy in anatomically complex and/or small hearts remain scarce.
Aims: We report single‐center results from an ongoing registry of all patients with congenital heart disease and all children with complex arrhythmias in which the Magnetic Navigation System (MNS) was used.
Results: Included in this report are 12 patients with CHD in whom 17 tachyarrhythmias were treated, and 11 pediatric patients with normal cardiac anatomy who each had a single arrhythmia. The procedures' duration and the duration of fluoroscopy time as well as arrhythmia recurrence rates were comparable to those found in previous reports of procedures performed in adults with structurally normal hearts, and the incidence of complications was quite low.
Discussion: In patients with complex congenital malformations, retrograde mapping of the pulmonary venous atrium was feasible, eliminating the need for puncture of the atrial septum, or surgically placed baffle in many cases. Moreover, the design of the catheter eliminated the need for multiple mapping and ablation catheters.
Conclusion: Our findings suggest that RFCA using the MNS for arrhythmias after surgery for congenital heart disease and in pediatric patients is safe and effective.
Atrio‐Pulmonary Vein Conduction Delay during Pulmonary Vein Isolation for Atrial Fibrillation Is Related to Vein Anatomy, Age, and Focal Activity
Authors: OFF MORTEN K. , SOLHEIM EIVIND , HOFF PER I. , SCHUSTER PETER , OHM OLE‐JØRGEN , CHEN JIAN 
Published: February 2009

Background: During pulmonary vein isolation for treatment of atrial fibrillation (AF), a significant delay in atrio‐pulmonary vein (PV) conduction is often observed. We sought to investigate this conduction delay in various PV in individual patients.
Methods: We studied 385 AF patients (mean age: 54 ± 11 years, 74 women) who underwent segmental PV isolation (PVI). A circular decapolar catheter was used to record electrograms at the PV ostia. The time delay from local atrial potential to PV potential was measured in each vein. Conduction delay (CD) was defined as the longest time interval >20 ms observed during PVI.
Results: For patients treated for the first time, CD was more frequently observed in the left common and the right and left superior PVs (84.2%, 67.9%, and 66.2%, respectively) and less frequently in the left and right inferior and right middle PVs (54.3%, 40.0%, and 30.8%, respectively). Veins with CD required more ablation applications (12.4 vs 9.9) and a higher ablated segmental fraction (72.3% vs 63.7%). CD was observed in 75.2% (109/145) of the PVs in which focal activity was detected. Older patients had a higher incidence of PVs with CD than younger patients. There were no gender differences.
Conclusions: The incidence of CD was highest in the left common and superior PVs, in older patients and in PVs with focal activity. PVs with CD required more ablation applications and a larger area of ablation around the ostia. These observations were not found during repeat procedures.