bluuebunny/crossref_metadata_2025_split huggingface dataset:
High frequency stimulation of the mamillothalamic tract for the treatment of resistant seizures associated with hypothalamic hamartoma
Authors: Khan Sadaquate , Wright Ingram , Javed Shazia , Sharples Peta , Jardine Philip , Carter Michael , Gill Steven S. 
Published: February 2009

SummaryWe investigate the clinical outcome from stimulation of the mamillothalamic tract in two patients with intractable epilepsy secondary to hypothalamic hamartomas. One patient has a left‐sided and the other a right‐sided tumor. Both patients presented with a history of gelastic and complex partial seizures resistant to multiple antiepileptic drugs. Both patients underwent insertion of a single deep brain‐stimulating electrode ipsilateral to the site of the tumor, lying adjacent to the mamillothalamic tract. Postoperatively they both had a significant reduction in seizure frequency, with one patient being seizure free for the last 10 months. An improvement in mood was reported by the patient’s primary carers and demonstrated on quality of life questionnaires.
Sleep‐Disordered Breathing in Recipients of Implantable Defibrillators
Authors: GRIMM WOLFRAM , SHARKOVA JULIA , HEITMANN JÖRG , JERRENTRUP ANDREAS , KOEHLER ULRICH , MAISCH BERNHARD 
Published: February 2009

Study Objectives: To examine the prevalence and clinical significance of sleep‐disordered breathing in patients with implantable cardioverter defibrillators (ICD).
Methods and Results: Overnight sleep studies were performed in 129 ICD recipients who had no history of sleep apnea. The mean left ventricular ejection fraction (LVEF) was 29 ± 11%. Mild, moderate, and severe sleep apnea was diagnosed in the presence of an apnea/hypopnea index (AHI) of 5–15/h, 15.1–30/h, and >30/h, respectively. No sleep apnea was present in 49 patients (38%), 57 (44%) had central sleep apnea (CSA), and 23 patients (18%) had obstructive sleep apnea (OSA). Mild, moderate, and severe sleep apnea were present in 25%, 31%, and 44% of patients with CSA, compared with 52%, 22%, and 26% of patients with OSA (P < 0.05). LVEF was similar in patients with versus without OSA or CSA. Patients with CSA were significantly older and had a higher prevalence of ischemic cardiomyopathy than patients without sleep apnea.
Conclusions: Previously undiagnosed CSA is common in ICD recipients. Severely disordered breathing during sleep was more prevalent among patients with CSA than patients with OSA. This prospective, observational study will examine the long‐term clinical significance of sleep‐disordered breathing in ICD recipients.
Backup Right Ventricular Pacing with a 0.035″ Guidewire during Implantation of Left Ventricular Leads
Authors: BURRI HARAN , SUNTHORN HENRI , ZIMMERMANN MARC , STETTLER CARINE , SHAH DIPEN 
Published: February 2009

Introduction: During implantation of biventricular devices, manipulation of the guiding sheath during localization of the coronary sinus (CS) ostium may result in injury to the right bundle and complete heart block. A preventive measure is to implant the right ventricular (RV) lead first, though this may interfere with manipulation of the guiding sheath and dislodge the permanent lead
. We tested the feasibility of backup pacing with a 0.035″ guidewire, advanced through the guiding sheath during CS localization.
Methods: One hundred six consecutive patients (mean age = 70 ± 11 years, 81 men) undergoing biventricular device implantation were studied. A 0.035″ guidewire with an uncoated tip was advanced into the right ventricle through the guiding sheath, and unipolar capture threshold, R‐wave sensing amplitude, and pacing impedance were measured.
Results: RV pacing was successful in all patients. The mean capture threshold was 3.8 ± 2.1 V/0.5 ms, R‐wave amplitude 5.4 ± 4.3 mV, and pacing impedance 226 ± 78 Ω. No arrhythmia was observed during the tests. Two patients developed complete heart block during the implant procedure and were successfully paced temporarily using the 0.035″ guidewire.
Conclusion: Temporary RV pacing, using a 0.035″ guidewire within the guiding sheath, is a simple, reliable, and safe method that allows backup pacing in case of traumatic complete heart block, developing during the implantation of biventricular devices.
Similar Long‐Term Benefits Conferred by Apical Versus Mid‐Septal Implantation of the Right Ventricular Lead in Recipients of Cardiac Resynchronization Therapy Systems
Authors: BULAVA ALAN , LUKL JAN 
Published: February 2009

Introduction: The benefits conferred by cardiac resynchronization therapy (CRT) are markedly influenced by the left ventricular (LV) lead placement. Little is known regarding the optimal right ventricular (RV) stimulation site.
Study Objective: To compare the long‐term outcomes of CRT in patients with RV leads placed in the mid‐septal region versus the apex.
Methods and Results: This nonrandomized, observational study included 117 patients with standard indications for CRT. The LV lead was implanted on the postero‐lateral or lateral LV wall, while the RV lead was implanted at the apex (n = 82) or in the mid‐septum (n = 35). Both groups were similar with respect to baseline clinical, demographic, and echocardiographic characteristics. After 12 months of CRT, the rates of clinical response to CRT were similar in both groups (63% vs. 66%), and similar degrees of reverse LV remodeling and LV resynchronization were observed on echocardiography and color tissue Doppler imaging. A ≥30% relative increase in LV ejection fraction (EF) occurred in 76% of patients in the RV apex group, versus 49% of patients in the RV mid‐septum group (P = 0.05). A ≥45% left ventricular ejection fraction (LVEF) was measured at 12 months in 40% of patients in the RV apex group, versus 31% in the RV mid‐septum group (ns).
Conclusions: RV mid‐septal stimulation was not associated with a higher rate of response to CRT or greater improvement in LV function compared to RV apical stimulation.
Contributions of Advanced Techniques to the Success and Safety of Transvenous Leads Extraction
Authors: MARIJON ELOI , BOVEDA SERGE , DE GUILLEBON MAXIME , JACOB SOPHIE , VAHDAT OLIVIER , BARANDON LAURENT , COMBES NICOLAS , SIDOBRE LAURENT , ALBENQUE JEAN‐PAUL , CLÉMENTY JACQUES , BORDACHAR PIERRE 
Published: February 2009

Purpose: We measured the proportion of intravascular leads, which can be extracted by simple traction versus with newer techniques, and examined the overall safety and success rate of lead extractions.
Methods: Between January 2005 and December 2007, 311 consecutive patients (mean age = 70 ± 14 years, 79% men) underwent extractions of 250 atrial, 318 ventricular, and 22 coronary sinus leads, in the surgical facilities of two experienced medical centers, under general anesthesia, at a mean of 7.2 ± 5.1 years (range 0.1–27.0) after lead implantation. Infection was the indication for extraction in 67.5% of cases. Complementary techniques were used when simple extraction with a locking stylet was unsuccessful.
Results: Simple traction, with or without a locking stylet, allowed the complete removal in 27.0% (95% confidence interval [CI] 22.1–31.9) of patients. A mechanical sheath, laser sheath, and/or lasso catheter were used in the remaining patients. The overall extraction success rate was 89.7% (95% CI 86.3–93.1). There was one procedure‐related death (0.3%; 95% CI 0.0–1.0). Among five other deaths occurring within 10 days after the procedure, four were due to septic shock. Duration of lead implantation was the strongest independent predictor of major adverse events (P = 0.002) and incomplete lead extraction (P = 0.005).
Conclusion: In contrast with simple traction, advanced techniques allowed the complete extraction of nearly 90% of leads. In experienced hands and with surgical back‐up, these techniques were safe. Patients presenting with infected implanted cardiac devices suffered a high rate of major adverse despite complete extraction of the lead(s).
Automated Template Matching to Pinpoint the Origin of Right Ventricular Outflow Tract Tachycardia
Authors: KUROSAKI KENJI , NOGAMI AKIHIKO , SAKAMAKI MIHIKO , KOWASE SHINYA , SUGIYASU AIKO , OGINOSAWA YASUSHI , KUBOTA SHOICHI 
Published: February 2009

Background: Template matching, a technique that examines the similarity between two QRS complexes, has not been broadly applied clinically.
Methods: The 16 patients enrolled in this study underwent radiofrequency catheter ablation (RFCA) at the site of five ventricular tachycardias (VT) and of premature ventricular contractions (PVC) arising from 25 sites in the right ventricular outflow tract (RVOT), under the guidance of conventional pace and activation mapping. After RFCA, (a) a template‐matching score using a correlation coefficient, and (b) a pace‐map score were calculated at 30 successful and 48 unsuccessful ablation sites.
Results: The template‐matching score at successful ablation sites (94 ± 4%) was significantly higher than at unsuccessful (85 ± 9%) ablation sites (P < 0.001). A ≥ 90% average matching score identified successful ablation sites with a sensitivity of 90% and specificity of 69%. While there was a significant correlation between the template‐matching score and visually judged pace‐map score (r = 0.63, P < 0.0001), the area under the receiver operating characteristic curve of the template matching score was larger than that of the pace‐map score (0.80 vs. 0.67).
Conclusions: Automated template matching was useful for localizing the optimal ablation site during RFCA of RVOT‐VT/PVC.
Nontransmural Scar Detected by Magnetic Resonance Imaging and Origin of Ventricular Tachycardia in Structural Heart Disease
Authors: YOKOKAWA MIKI , TADA HIROSHI , KOYAMA KEIKO , NAITO SHIGETO , OSHIMA SHIGERU , TANIGUCHI KOICHI 
Published: February 2009

Background: Contrast‐enhanced magnetic resonance imaging (CMR) identifies scar tissue as an area of delayed enhancement (DE). The scar region might be the substrate for ventricular tachycardia (VT). However, the relationship between the occurrence of VT and the characteristics of scar tissue has not been fully studied.
Methods: CMR was performed in 34 patients with monomorphic, sustained VT and dilated cardiomyopathy (DCM, n = 18), ischemic cardiomyopathy (ICM, n = 10), or idiopathic VT (IVT, n = 6). The VT exit site was assessed by a detailed analysis of the QRS morphology, including bundle branch block type, limb lead polarity, and precordial R‐wave transition. On CMR imaging, the transmural score of each of the 17 segments was assigned, using a computer‐assisted, semiautomatic technique, to measure the DE areas. Segmental scars were classified as nontransmural when DE was 1–75% and transmural when DE was 76–100% of the left ventricular mass in each segment.
Results: A scar was detected in all patients with DCM or ICM. Nontransmural scar tissue was often found at the VT exit site, in patients with DCM or ICM. In contrast, no scar was found in patients with IVT.
Conclusions: CMR clarified the characteristics and distribution of scar tissue in patients with structural heart disease, and the presence and location of scar tissue might predict the VT exit site in these patients.
Electrocardiographic Measurements of Regional Atrial Fibrillation Cycle Length
Authors: RAVI KRISHNA C. , KRUMMEN DAVID E. , TRAN AILINH J. , BULLINGA JOHN R. , NARAYAN SANJIV M. 
Published: February 2009

Background: Differences in atrial fibrillation (AF) cycle length (CL) between the left (LA) and right (RA) atrium and coronary sinus (CS) may help separate paroxysmal from persistent AF and identify patients most likely to respond to pulmonary vein isolation, but has not been measured noninvasively.
Methods and Results: We developed methods to estimate regional intraatrial AF CL from the surface electrocardiogram (ECG) in 20 patients with persistent AF and 10 patients with paroxysmal AF prior to ablation. Intraatrial AF CL was measured near the LA appendage, mid‐CS, and lateral RA. In simultaneous filtered ECG, AF CL was estimated using autocorrelation. The mean of ECG‐derived AF CL in leads V5, I, and aVL was used to estimate LA CL; leads aVF, II, and III for CS CL; and V1, V2, and aVR for RA CL. ECG CL estimates for the LA, CS, and RA had R2 > 0.91 versus measured CL (all P < 0.001). Though magnitudes of left‐versus‐right AF CL gradients were small in this series, the ECG predicted the direction of gradients in 62% of measurements (P < 0.05). When the gradient was >10 ms, the direction was accurately predicted in eight of 11 patients. The accuracy of AF CL estimates was not adversely affected by AF type or LA dilatation (≤40 or >40 mm). The ECG‐estimated AF‐CL showed high 5‐minute temporal stability (P < 0.001 each chamber).
Conclusions: Left and right atrial AF CL, and their gradients, can be accurately determined from the ECG using autocorrelation analysis. This approach may be a helpful guide prior to ablation procedures.
Discrimination between His‐bundle and the Right Bundle Branch during Electrophysiologic Studies
Authors: KANEKO YOSHIAKI , NAKAJIMA TADASHI , SAITO AKIHIRO , IRIE TADANOBU , OTA MASAKI , KATO TOSHIMITSU , IIJIMA TAKAFUMI , MANITA MAMORU , ITO TOSHIO , AKIYAMA MASAHIRO , TANIGUCHI YASUHIRO , KURABAYASHI MASAHIKO 
Published: February 2009

Background: The purpose of this study was to identify the His‐bundle (HB) versus right bundle branch (RBB) during electrophysiologic studies, using the V3 phenomenon, and to compare the timing of HB versus RBB potentials of sinus cycles (His‐ventricular [H‐V] interval).
Methods: The study enrolled 16 patients without structural heart disease, who underwent electrophysiologic studies during which the H‐V interval was within normal limits and the V3 phenomenon was induced during recordings of the HB and the RBB potentials by a multi‐electrode catheter. The recording site of the earliest HB potential just before the V3 phenomenon was defined as the branching portion of His bundle (HBBP), the site immediately proximal to the HBBP as the HB, and the site immediately distal to the HBBP as the RBB.
Results: The HBBP was identified in all patients. In all cases but one patient, the H‐V interval measured at the HB adjacent to the HBBP was ≥35 ms. However, in 12 patients, the H‐V interval measured at the RBB adjacent to the HBBP was also ≥35 ms.
Conclusions: The electrophysiologic identification of HB versus RBB by simultaneous recordings of HB and RBB potentials during induction of the V3 phenomenon was feasible. When the discrimination between HB and RBB was based on the measurement of the H‐V interval, the proximal portion of the RBB was frequently misidentified as the HB.
Accuracy of Swabs, Tissue Specimens, and Lead Samples in Diagnosis of Cardiac Rhythm Management Device Infections
Authors: GOLZIO PIER‐GIORGIO , VINCI MELISSA , ANSELMINO MATTEO , COMOGLIO CHIARA , RINALDI MAURO , TREVI GIAN P. , BONGIORNI MARIA GRAZIA 
Published: February 2009

Aims: Pacemaker and implantable‐cardioverter defibrillator lead infections widely increased with consequent need to accurately recognize responsible bacteria.
Methods: Between May 2003 and December 2007, we extracted 118 leads, 104 (87.3%) due to infections (sepsis, lead‐associated endocarditis, pocket infection) or chronic draining sinus (with negative local bacteriological analyses). Swabs and tissue specimens from pocket and fragments of pin and tip of each extracted lead were obtained during extraction and sent for bacteriological examination.
Results: Cultures from explanted lead pins returned positive results in 100% of the cases presenting with local infections and in 92.5% of those with chronic draining sinus. In cases of sepsis, positive results of blood samples are less common than lead samples (58.3 vs 86.7, P = 0.02), the latter being more sensitive for infection diagnosis. Concordance between bacterial isolates from pocket and lead is quite low, approaching 45%, seemingly due to contamination effect. Concordance between isolates within the lead (pin and tip) is quite high, close to 70%, reflecting a more accurate expression of the real infection. In cases of sepsis, concordance between lead and blood samples, and mainly from tip and blood, is very high, resembling 80–85%; consequently bacterial isolates from the lead, particularly from lead tip, are clearly associated with clinical infections.
Conclusions: Our results strongly support the hypothesis that chronic draining sinus is often sustained by infection. Moreover, diagnostic accuracy of lead samples is higher not only than swabs and tissue samples, but also than blood samples to confirm an infection and to guide effective therapy.
Optimal Programming of the Atrioventricular Delay Using the Phonocardiogram
Authors: MIKI YUKO , ISHIKAWA TOSHIYUKI , MATSUSHITA KOHEI , YAMAKAWA YOUHEI , MATSUMOTO KATSUMI , SUMITA SHINICHI , UCHINO KAZUAKI , KIMURA KAZUO , UMEMURA SATOSHI 
Published: February 2009

Purpose: To predict the optimal atrioventricular (AV) delay using the phonocardiogram (PCG).
Methods: We studied 12 recipients of cardiac resynchronization therapy (CRT) system and eight recipients of dual‐chamber pacemakers implanted for AV block with normal left ventricular (LV) function. The amplitude of the first heart sound (S1) was recorded by PCG and the LV outflow tract (OT) time‐velocity integral (TVI) was measured by pulsed Doppler echocardiography. The AV delay was prolonged in 20‐ms increments, from 60 ms to 240 ms. Ishikawa's method was used for the echocardiographic optimization of the AV delay. The relation between S1 amplitude and the AV delay was analyzed.
Results: The correlation between the amplitude of S1 and the length of AV delay showed an S‐shaped curve. The AV delay at the inflection point of each patient's S‐shaped curve (161.2 ± 19.5 ms) was positively correlated with the optimal AV delay determined by echocardiography (148.3 ± 16.9 ms, r = 0.83, P < 0.001). In addition, there was a positive correlation between the AV delay at the maximal TVI of LVOT (150.8 ± 22.7 ms) and the AV delay at the inflection point of the S‐shaped curve (159.5 ± 24.9 ms, r = 0.87, P < 0.001). In two CRT system recipients, an optimal AV delay could not be found by echocardiography; however, an optimal AV delay could be determined by PCG.
Conclusions: A high correlation was observed between the optimal AV delay determined by phonocardiography versus echocardiography.
Abnormal Atrioventricular Node Conduction and Atrioventricular Nodal Reentrant Tachycardia in Patients Older Versus Younger Than 65 Years of Age
Authors: GRECU MIHAELA , FLORIA MARIANA , GEORGESCU CATALINA ARSENESCU 
Published: February 2009

Study Objective: We examined the possible role of atrioventricular node (AVN) conduction abnormalities as a cause of AVN reentrant tachycardia (RT) in patients >65 years of age.
Study Population: Slow pathway radiofrequency catheter ablation (RFCA) was performed in 104 patients. Patients in group 1 (n = 14) were >65 years of age and had AV conduction abnormalities associated with structural heart disease. Patients in group 2 (n = 90) were <65 years of age and had lone AVNRT.
Results: Patients in group 1 versus group 2 (66% vs. 46% men) had a first episode of tachycardia at an older age than in group 2 (68 ± 16.8 vs 32.5 ± 18.8 years, P = 0.007). The history of arrhythmia was shorter in group 1 (5.4 ± 3.8 vs 17.5 ± 14, P = 0.05) and was associated with a higher proportion of patients with underlying heart disease than in group 2 (79% vs 3%, P < 0.001). The electrophysiological measurements were significantly shorter in group 2: atrial‐His interval (74 ± 17 vs 144 ± 44 ms, P = 0.005), His‐ventricular (HV) interval (41 ± 5 vs 57 ± 7 ms, P = 0.001), Wenckebach cycle length (329 ± 38 vs 436 ± 90 ms, P = 0.001), slow pathway effective refractory period (268 ± 7 vs 344 ± 94 ms, P = 0.005), and tachycardia cycle length (332 ± 53 vs 426 ± 56 ms, P = 0.001). The ventriculoatrial block cycle length was similar in both groups. The immediate procedural success rate was 100% in both groups, and no complication was observed in either group. One patient in group 2 had recurrence of AVNRT. One patient with a 98‐ms HV interval underwent permanent VVI pacemaker implantation before RFCA procedure.
Conclusion: In patients undergoing RFCA for AVNRT at >65 years of age had a shorter history of tachycardia‐related symptoms than patients with lone AVNRT. The longer AVN conduction intervals and refractory period might explain the late development of AVNRT in group 1.
Role of Pulmonary Veins Isolation in Persistent Atrial Fibrillation Ablation:
Authors: STABILE GIUSEPPE , BERTAGLIA EMANUELE , TURCO PIETRO , ZOPPO FRANCO , IULIANO ASSUNTA , ZERBO FRANCESCA , LA ROCCA VINCENZO , DE SIMONE ANTONIO 
Published: February 2009

Background: The role of pulmonary veins (PV) isolation in patients with persistent atrial fibrillation (AF) is still debated. The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation (anatomical approach).
Methods: We treated 97 consecutive patients presenting with drug‐refractory persistent AF by an anatomical approach (group A, n = 36, mean age = 60 ± 8 years, 29 males) or an integrated approach (group B, n = 61, mean age 59 ± 10 years, 48 males). In all patients, radiofrequency (RF) ablation was performed by means of a nonfluoroscopic navigation system, in order to anatomically create circumferential lines around the PV. In group B, the persistence of PV potentials was ascertained with a multipolar circular catheter. If PV potentials persisted, RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV. Past a 2‐month period of observation, success was defined as absence of any atrial tachyarrhythmia recurrence lasting >30 seconds.
Results: Total procedure duration (220 ± 62 minutes vs 140 ± 43 minutes, P < 0.001), fluoroscopy time (35 ± 15 minutes vs 17 ± 9 minutes, P < 0.001), and RF delivery time (48 ± 22 minutes vs 27 ± 9 minutes, P < 0.001) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 ± 9.1 months, 21 patients in group A (58%) and 34 patients in group B (56%) were free of atrial tachyarrhythmia recurrence (P = 0.9).
Conclusions: In patients with persistent AF, who underwent an anatomical approach, electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times, without effect on the long‐term outcomes.