bluuebunny/crossref_metadata_2025_split huggingface dataset:
Consumption rate and susceptibility to parasitic nematodes and chemical molluscicides of the pest slugsArion hortensiss. s. andA. distinctusJ.Iglesias, B.Speiser, Biological and chemical control of Arion hortensis s. l. slugs
Authors: Iglesias J. , Speiser B. 
Published: December 2003

AbstractThe species complexArion hortensiss. l. is among the most important pestiferous slugs in Europe. The speciesA. distinctusMabille andA. hortensisde Férussac have traditionally been grouped together under the denominationA. hortensis. Therefore, neither the feeding behaviour nor the susceptibility of the individual species to control measures are known. In the laboratory, mean daily consumption of lettuce was similar for both species. In a series of laboratory bioassays,A. distinctusandA. hortensiss. s. were exposed to the rhabditid nematodePhasmarhabditis hermaphroditaand to the chemical molluscicides metaldehyde and iron phosphate, and their feeding and health were measured. Both species showed a similar and low susceptibility to the biocontrol agentP. hermaphrodita. In field‐collected slugs, the incidence of nematodes was much lower inA. hortensiss. l. than inDeroceras reticulatumorArion lusitanicus.Metaldehyde and iron phosphate affected both slug species similarly. Therefore, our results do not indicate any major difference between the two slug species of agronomical relevance.
Failure of antiretroviral therapy to control Varicella zoster retinitis
Authors: Ramsay Andrew , Young Stephanie , Lightman Susan 
Published: December 2003

ABSTRACTThe term necrotizing herpetic retinopathies encompasses a spectrum of diseases which includes cytomegalovirus (CMV) retinitis, acute retinal necrosis (ARN) and Varicella zoster retinitis (VZR). Varicella zoster retinitis is a rapidly progressive, necrotizing condition most commonly reported in patients with AIDS. A case of vitreous biopsy‐proven VZR is reported in a patient with AIDS that progressed despite immune recovery on highly active antiretroviral therapy (HAART) to a viral load < 50 copies/mL and a CD4 count of 230 cells/μL. This is in contrast to CMV retinitis in which maintenance therapy appears unnecessary once the CD4 count rises and the viral load falls on HAART. Patients with VZR and AIDS should therefore be monitored for reactivation of retinal disease despite HAART‐induced remission.
Left Atrial Radiofrequency Ablation During Cardiac Surgery in Patients with Atrial Fibrillation
Authors: MANTOVAN ROBERTO , RAVIELE ANTONIO , BUJA GIANFRANCO , BERTAGLIA EMANUELE , CESARI FRANCESCO , PEDROCCO ALESSANDRA , ZUSSA CLAUDIO , GEROSA GINO , VALFRÈ CARLO , STRITONI PAOLO ,   North‐eastern Italian Study on Radiofrequency Surgical Treatment of Atrial Fibrillation Investigators
Published: December 2003

Introduction: Intraoperative left atrial radiofrequency (RF) ablation recently has been suggested as an effective surgical treatment for atrial fibrillation (AF). The aim of this study was to verify the outcome of this technique in a controlled multicenter trial. Methods and Results: One hundred three consecutive patients (39 men and 65 women; age 62 ± 11 years) affected by AF underwent cardiac surgery and RF ablation in the left atrium (RF group). The control group consisted of 27 patients (6 men and 21 women; age 64 ± 7 years) with AF who underwent cardiac surgery during the same period and refused RF ablation. Mitral valve disease was present in 89 (86%) and 25 (92%) patients, respectively (P = NS). RF endocardial ablation was performed in order to obtain isolation of both right and left pulmonary veins, a lesion connecting the previous lines, and a lesion connecting the line encircling the left veins to the mitral annulus. Upon discharge from the hospital, sinus rhythm was present in 65 patients (63%) versus 5 patients (18%) in the control group (P < 0.0001). Mean time of cardiopulmonary bypass was longer in the RF group (148 ± 50 min vs 117 ± 30 min, P = 0.013). The complication rate was similar in both groups, but RF ablation‐related complications occurred in 4 RF group patients (3.9%). After a mean follow‐up of 12.5 ± 5 months (range 4–24), 83 (81%) of 102 RF group patients were in stable sinus rhythm versus 3 (11%) of 27 in the control group (P < 0.0001). The success rate was similar among the four surgical centers. Atrial contraction was present in 66 (79.5%) of 83 patients in the RF group in sinus rhythm. Conclusion: Endocardial RF left atrial compartmentalization during cardiac surgery is effective in restoring sinus rhythm in many patients. This technique is easy to perform and reproducible. Rare RF ablation‐related complications can occur. During follow‐up, sinus rhythm persistence is good, and biatrial contraction is preserved in most patients. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1289‐1295, December 2003)
Identification of Pulmonary Vein Potentials by Differential Site Atrial Pacing in Patients with Paroxysmal Atrial Fibrillation:
Authors: IWASA ATSUSHI , A. STOREY JAMES , TASHAKKOR BABAK , K. FELD GREGORY 
Published: December 2003

Introduction: Pulmonary vein (PV) isolation may cure paroxysmal atrial fibrillation (PAF); however, identification of PV potentials may be difficult in sinus rhythm. Studies have suggested that atrial pacing may improve the identification of PV potentials. Methods and Results: In 25 consecutive patients who underwent PV isolation for PAF, the results of pacing from the distal PV, distal and proximal coronary sinus, and high right atrium compared to sinus rhythm were analyzed to determine the most effective pacing site for identification of PV potentials. The percentage of confirmed PV potentials and the longest interval between atrial and PV potentials in each PV were compared during differential site pacing and sinus rhythm. PV potentials were confirmed in 63 (82%) of 77 PVs that could be mapped during the complete pacing protocol and during sinus rhythm. Distal PV pacing identified significantly more PV potentials (left upper pulmonary vein [LUPV] 100%, left lower pulmonary vein [LLPV] 84%, right upper pulmonary vein [RUPV] 80%, right lower pulmonary vein [RLPV] 53%) compared to other pacing sites and sinus rhythm. Among atrial pacing sites, those ipsilateral to the PV being mapped were the most effective for identifying PV potentials. The intervals between atrial and PV potentials were significantly longer during distal PV pacing than pacing at other sites (LUPV 81.6 ± 26.2 ms, LLPV 61.4 ± 26.1 ms, RUPV 59.7 ± 33.2 ms, RLPV 39.7 ± 26.7 ms). Conclusion: (1) Distal PV pacing was most effective for identifying PV potentials. (2) The interval between atrial and PV potentials was longest during distal PV pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1311‐1318, December 2003)
Total Atrioventricular Nodal Ablation Increases Atrial Fibrillation Burden in Patients with Paroxysmal Atrial Fibrillation Despite Continuation of Antiarrhythmic Drug Therapy
Authors: WILLEMS RIK , WYSE D. GEORGE , M. GILLIS ANNE ,   Atrial Pacing Periablation for Paroxysmal Atrial Fibrillation (PA) Study Investigators
Published: December 2003

Introduction: Total atrioventricular nodal (TAVN) ablation and pacing is an accepted and safe treatment for patients with drug‐refractory paroxysmal atrial fibrillation (AF). Many patients develop permanent AF within the first 6 months after TAVN ablation. This usually is ascribed to the cessation of antiarrhythmic drug therapy. We hypothesized that TAVN ablation itself creates an atrial substrate prone to AF. Methods and Results: Patients participating in the Atrial Pacing Periablation for Paroxysmal Atrial Fibrillation (PA3) study who remained on stable antiarrhythmic drug therapy throughout follow‐up were included in this analysis. AF burden and the development of persistent AF in the preablation period were compared to two consecutive postablation periods. Echocardiographic changes also were evaluated. Twenty‐two patients remained on stable drug therapy (9 men and 13 women, age 59 ± 3 years). One patient developed persistent AF preablation compared to 10 postablation (P < 0.05). AF burden preablation was 3.0 ± 1.2 hours/day and increased to 10.4 ± 2.2 hours/day and 11.8 ± 2.3 hours/day in the two postablation follow‐up periods (P < 0.05). In patients with fractional shortening (FS) >30% prior to ablation, FS decreased significantly from 39.4%± 1.3% to 36.4%± 1.7% (P < 0.05). In contrast, in patients with a FS ≤30% prior to ablation, FS increased from 27%± 0.8% to 33.6 ± 1.7% (P < 0.05). Conclusion: TAVN ablation increases AF burden and facilitates the development of persistent AF in patients with paroxysmal AF despite the continuation of antiarrhythmic drugs. Loss of AV and/or interventricular synchrony may lead to altered cardiac hemodynamics resulting in atrial stretch and increasing AF burden. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1296‐1301, December 2003)
Effects of Elevated Extracellular Potassium Ion Concentration on Anodal Excitation of Cardiac Tissue
Authors: ROTH BRADLEY J. , PATEL SALIL G. 
Published: December 2003

Introduction: Anodal excitation of cardiac tissue occurs by two mechanisms: “make” and “break.” Anodal strength‐interval curves are divided into two sections, with break excitation occurring at short intervals and make at long intervals. Our goal is to determine how an elevated extracellular potassium ion concentration, [K]o, affects the mechanism of anodal excitation and influences the anodal strength‐interval curve. Methods and Results: Computer simulations of unipolar stimulation were performed using the bidomain model, with membrane kinetics governed by the Luo‐Rudy model. The diastolic threshold for anodal stimulation first decreased and then increased with increasing [K]o, reaching a minimum value at [K]o= 12 mM. The mechanism for diastolic anodal excitation was make for all [K]o values except 13.3 mM, in which case it was break. For low [K]o (4 and 8 mM) the break section of the anodal strength‐interval contained a “dip,” but for high [K]o (12 and 13 mM), the dip disappeared. Conclusion: High [K]o predisposes cardiac tissue to break excitation, which is thought to play an important role in reentry induction and defibrillation. Because fibrillation raises extracellular [K]o levels, break excitation may play a more important role in defibrillation than is suggested by simulations and experiments using normal [K]o values. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1351‐1355, December 2003)
Spontaneous Transition of 2:1 Atrioventricular Block to 1:1 Atrioventricular Conduction During Atrioventricular Nodal Reentrant Tachycardia:
Authors: LEE SHIH‐HUANG , TAI CHING‐TAI , CHIANG CHERN‐EN , YU WEN‐CHUNG , CHENG JUN‐JACK , DING YU‐AN , CHANG MAU‐SONG , CHEN SHIH‐ANN 
Published: December 2003

Introduction: The incidence of spontaneous transition of 2:1 AV block to 1:1 AV conduction during AV nodal reentrant tachycardia has not been well reported. Among previous studies, controversy also existed about the site of the 2:1 AV block during AV nodal reentrant tachycardia. Methods and Results: In patients with 2:1 AV block during AV nodal reentrant tachycardia, the incidence of spontaneous transition of 2:1 AV block to 1:1 AV conduction and change of electrophysiologic properties during spontaneous transition were analyzed. Among the 20 patients with 2:1 AV block during AV nodal reentrant tachycardia, a His‐bundle potential was absent in blocked beats during 2:1 AV block in 8 patients, and the maximal amplitude of the His‐bundle potential in the blocked beats was the same as that in the conducted beats in 4 patients and was significantly smaller than that in the conducted beats in 8 patients (0.49 ± 0.25 mV vs 0.16 ± 0.07 mV, P = 0.007). Spontaneous transition of 2:1 AV block to 1:1 AV conduction occurred in 15 (75%) of 20 patients with 2:1 AV block during AV nodal reentrant tachycardia. Spontaneous transition of 2:1 AV block to 1:1 AV conduction was associated with transient right and/or left bundle branch block. The 1:1 AV conduction with transient bundle branch block was associated with significant His‐ventricular (HV) interval prolongation (66 ± 19 ms) compared with 2:1 AV block (44 ± 6 ms, P < 0.01) and 1:1 AV conduction without bundle branch block (43 ± 6 ms, P < 0.01). Conclusion: The 2:1 AV block during AV nodal reentrant tachycardia is functional; the level of block is demonstrated to be within or below the His bundle in a majority of patients with 2:1 AV block during AV nodal reentrant tachycardia, and a minority are possibly high in the junction between the AV node and His bundle. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1337‐1341, December 2003)
Development and Validation of an ECG Algorithm for Identifying the Optimal Ablation Site for Idiopathic Ventricular Outflow Tract Tachycardia
Authors: ITO SACHIKO , TADA HIROSHI , NAITO SHIGETO , KUROSAKI KENJI , UEDA MAREHIKO , HOSHIZAKI HIROSHI , MIYAMORI ISAMU , OSHIMA SHIGERU , TANIGUCHI KOICHI , NOGAMI AKIHIKO 
Published: December 2003

Introduction: Idiopathic ventricular outflow tract tachycardia or premature ventricular contractions (OT‐VTs) can originate from several different sites in the outflow tract, including the left ventricular (LV) endocardium and epicardium. The aims of this study were (1) to develop an ECG algorithm to predict the origin of OT‐VT and (2) to test prospectively the accuracy of the algorithm. Methods and Results: An algorithm was developed by correlating the 12‐lead ECG findings with the catheter ablation site in 80 patients with OT‐VT. The ECG characteristics of the QRS complex during the arrhythmia were analyzed. The catheter sites were verified by multiplane fluoroscopy. The outflow tract was classified into six subdivisions: right ventricular (RV) septum, RV free wall, RV near the His‐bundle region, LV endocardium, left sinus of Valsalva (LSV), and LV epicardium remote from the LSV. An OT‐VT originating from the LV epicardium remote from the LSV was defined as an OT‐VT in which the earliest ventricular activation was recorded at the LSV and radiofrequency ablation from the LSV failed. This algorithm subsequently was tested prospectively in 88 patients. Overall sensitivity was 88% and specificity was 95%. The positive and negative predictive values were 88% and 96%, respectively. Conclusion: We describe a new ECG algorithm having a high sensitivity and specificity to identify the optimal ablation site for idiopathic ventricular outflow tachycardia or premature ventricular contractions. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1280‐1286, December 2003)
Atrioventricular Nodal Ablation and His‐Bundle Pacing:
Authors: OLIVIER N. BARI , EYSTER GEORGE E. , SANDERS ROB , CHENG JIE , BOHART GEORGE , GIRAND MIKE , BAILIE MARC 
Published: December 2003

Introduction: QT interval prolongation following drug exposure is considered a marker for increased risk of drug‐induced arrhythmias. QT interval measurements are common components of the safety pharmacology assessment of new therapeutic compounds but are potentially confounded by concurrent changes in heart rate that also alter QT intervals. We describe an anesthetized canine model of AV dissociation with His‐bundle pacing that overcomes the confounding effects of a change in heart rate. Methods and Results: Transvenous radiofrequency ablation of the AV node was performed in isoflurane‐anesthetized dogs and followed by open chest implantation of bipolar pacing electrodes in the vicinity of the His bundle. Pace rates were adjusted from 50 to 190 in steps of 20 beats/min, holding each step for 30 seconds. At each paced rate, QT intervals were measured manually to the nearest 1 ms to construct paced QT interval‐heart rate (QT‐HR) relationships. Paired QT‐HR relationships using identical ascending ramps of pace rates were compared to paired QT‐HR relationships with an ascending and descending pace ramp to evaluate short‐term reproducibility and hysteresis effects. For proof of concept, an additional QT‐HR relationship was constructed in three dogs after intravenous administration of a compound known to alter QT intervals: one dog received terfenadine (0.48 mg/kg bolus followed by 0.017 mg/kg/min infusion), one dog received quinidine (20 mg/kg), and the third dog received sotalol (1 and 3 mg/kg). Substantial interdog variation was found for QT‐HR, although short‐term reproducibility was high within one dog (average absolute difference for paired ascending ramps <5 ms). QT intervals measured during descending paced ramps were generally lower than the value for the corresponding paced rate on an ascending ramp. This hysteretic effect was small, averaging <7 ms over the entire ramp. All test compounds prolonged QT intervals and shifted the QT‐HR relationship upward. Maximal QT prolongation was 30 ms for terfenadine, 50 ms for quinidine, and 59 ms for sotalol. Conclusion: AV nodal ablation and His‐bundle pacing provide a sensitive animal model to identify acute effects of test compounds on indices of myocardial repolarization such as the QT interval. The model is devoid of confounding effects of changing heart rates while enabling identification of effects of drugs over a wide range of controlled rates. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1356‐1360, December 2003)
Role of the Coronary Sinus in Maintenance of Atrial Fibrillation
Authors: ORAL HAKAN , OZAYDIN MEHMET , CHUGH AMAN , SCHARF CHRISTOPH , TADA HIROSHI , HALL BURR , CHEUNG PETER , PELOSI FRANK , KNIGHT BRADLEY P. , MORADY FRED 
Published: December 2003

Introduction: Bursts of tachycardia arising in the pulmonary veins may play an important role in perpetuating atrial fibrillation (AF). However, the role of the coronary sinus (CS) in the perpetuation of AF has been unclear. The aim of this study was to determine whether the CS plays a role in perpetuation of AF. Methods and Results: Pulmonary vein isolation was performed by segmental ostial ablation with radiofrequency energy in 22 consecutive patients with paroxysmal AF. Bipolar and unipolar electrograms recorded in the left atrium and CS were analyzed during atrial pacing from the mitral annulus and during AF. There was a mean of 2.5 ± 0.5 electrical connections between the CS and the left atrium. The electrical connections between the left atrium and CS were ablated with a mean of 6.2 ± 2.7 minutes of radiofrequency energy applied along the atrial side of the inferior mitral annulus. During AF, episodes of intermittent tachycardia alternated between the left atrium and the CS. Among the 22 patients, sustained AF was still inducible in 9 after pulmonary vein isolation. After electrical disconnection of the CS from the left atrium, sustained AF was inducible in only 3 of these 9 patients. Conclusion: The CS may be a source of rapid repetitive electrical activity during AF. The lower probability of inducible sustained AF after electrical disconnection of the CS from the left atrium suggests that the CS may play a role in perpetuating AF. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1329‐1336, December 2003)
Para‐Hisian Entrainment: A Novel Pacing Maneuver to Differentiate Orthodromic Atrioventricular Reentrant Tachycardia from Atrioventricular Nodal Reentrant Tachycardia
Authors: Y. REDDY VIVEK , JONGNARANGSIN KRIT , M. ALBERT CHRISTINE , SABBOUR HANI , KEANE DAVID , MELA THEOFANIE , MCGOVERN BRIAN , N. RUSKIN JEREMY 
Published: December 2003

Introduction: Para‐Hisian pacing during sinus rhythm can help to identify the presence of an accessory pathway (AP). In this maneuver, the retrograde activation time and pattern are compared during capture and loss‐of‐capture of the His bundle while pacing from a para‐Hisian position. However, identification of a retrograde AP does not necessitate that it is operative during the tachycardia of interest; conversely, slowly conducting or “distant” bypass tracts may not be identified. We evaluated the utility of entrainment or resetting of tachycardias from the para‐Hisian position to help distinguish atrioventricular nodal reentrant tachycardia (AVNRT) from orthodromic atrioventricular tachycardia (AVRT). Methods and Results: Para‐Hisian entrainment/resetting was evaluated in 50 patients: 33 with AVNRT and 17 with AVRT. The maneuvers were performed using a standard quadripolar catheter placed at the His position: low output for right ventricular (RV) capture and high output for both RV and His capture. The retrograde atrial activation sequence, SA interval (interval from stimulus to earliest retrograde atrial activation), and “local” VA interval (interval between the ventricular and atrial electrograms at the site of earliest retrograde atrial activation) were compared between His and His/RV capture. The ΔSA was >40 ms in patients with AVNRT and was <40 ms in all but one patient with AVRT. In concert with the ΔSA interval, the ΔVA interval was able to fully define the mechanism of the tachycardia in all patients studied. Conclusion: Para‐Hisian entrainment/resetting can determine the course of retrograde conduction operative during narrow complex tachycardias. It is a useful diagnostic maneuver in differentiating AVNRT and orthodromic AVRT. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1321‐1328, December 2003)
Congenital Short QT Syndrome and Implantable Cardioverter Defibrillator Treatment:
Authors: SCHIMPF RAINER , WOLPERT CHRISTIAN , BIANCHI FRANCESCA , GIUSTETTO CARLA , GAITA FIORENZO , BAUERSFELD URS , BORGGREFE MARTIN 
Published: December 2003

Introduction: A congenital short QT interval constitutes a new primary electrical abnormality associated with syncope and/or sudden cardiac death. We report on the initial use of implantable cardioverter defibrillator (ICD) therapy in patients with inherited short QT interval and discuss sensing abnormalities and detection issues. Methods and Results: In five consecutive patients from two unrelated European families who had structurally normal hearts, excessively shortened QT intervals, and a strong positive family history of sudden cardiac death, ICDs were placed for primary and secondary prevention. Mean QT intervals were 252 ± 13 ms (QTc 287 ± 13 ms). Despite normal sensing behavior during intraoperative and postoperative device testing, 3 of 5 patients experienced inappropriate shock therapies for T wave oversensing 30 ± 26 days after implantation. Programming lower sensitivities and decay delays prevented further inappropriate discharges. Conclusion: The congenital short QT syndrome constitutes a new clinical entity with an increased risk for sudden cardiac death. Currently, ICD treatment is the only therapeutic option. In patients with short QT interval and implanted ICD, increased risk for inappropriate therapy is inherent due to the detection of short‐coupled and prominent T waves. Careful testing of ICD function and adaptation of sensing levels and decay delays without sacrificing correct arrhythmia detection are essential. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1273‐1277, December 2003)