bluuebunny/crossref_metadata_2025 huggingface dataset:
Is a Cooled Tip Catheter the Solution for the Ablation of the Cavotricuspid Isthmus?
Authors: SCAVÉE C. , GEORGER F. , JAMART J. , MANCINI I. , COLLET B. , BLOMMAERT D. , ROY L. DE
Published: December 2004

SCAVÉE, C., et al.: Is a Cooled Tip Catheter the Solution for the Ablation of the Cavotricuspid Isthmus?
To test the theoretical superiority of irrigated tip catheters to achieve complete cavotricuspid isthmus block, a 4‐mm cooled tip catheter was compared to a conventional 8‐mm tip catheter with a double temperature sensor in the cavotricuspid isthmus (CTI) ablation. The study prospectively enrolled 60 patients (47 men, mean

65 ± 10

years) with common flutter divided in group 1

(n = 30)

assigned to an 8‐mm tip catheter versus group 2

(n = 30)

, assigned to an internal circuit, irrigated tip catheter. Linear radiofrequency applications were performed in a point‐by‐point protocol to achieve complete CTI block. Complete CTI block was achieved in 29 patients in each group. Mean durations of procedure and fluoroscopy were 91 versus 90 and 40 versus 33 minutes in group 1 versus 2, respectively, (NS). The mean number/patient of RF pulses to interrupt atrial flutter was four in group 1 and eight in group 2

(P = 0.034)

, and 11 and 13, respectively, to interrupt CTI conduction (NS). The total energy delivered was similar in both groups (29,237 vs 23,236 W/s, NS). CTI ablation with a conventional 8‐mm tip catheter versus an irrigated tip catheter was associated with similar success rates, procedure duration, and fluoroscopic exposure. The technical complexity of the cooled tip catheter renders it less competitive. (PACE 2003; 26[Pt. II]:328–331)
Flecainide Test in Brugada Syndrome: A Reproducible but Risky Tool
Authors: GASPARINI MAURIZIO , PRIORI SILVIA G. , MANTICA MASSIMO , NAPOLITANO CARLO , GALIMBERTI PAOLA , CERIOTTI CARLO , SIMONINI STEFANO
Published: December 2004

GASPARINI, M., et al.: Flecainide Test in Brugada Syndrome: A Reproducible but Risky Tool.
The flecainide test is widely used in Brugada syndrome. However, its reproducibility and safety remain ill‐defined. This study included 22 patients (18 men, mean age 34 years). Mutations in the SCN5A gene were found in eight patients. Two patients had aborted sudden cardiac death, 8 had syncope/presyncope, and 12 were asymptomatic. The ECG was diagnostic in 19 patients and suggestive in 3. At baseline, 21 of 22 patients underwent a flecainide test (2 mg/kg IV bolus over 10 minutes). In 21 of 21 patients the test was diagnostic or amplified the typical ECG pattern. At the end of drug infusion, sustained VT lasting 7–10 minutes developed in two patients. A second flecainide test was performed within 2 months in 20 patients. The test was not repeated in the two patients with prior development of VT. The flecainide test was diagnostic in 20 of 20 patients. Sustained VT occurred in one patient and recurrent VF in another. The reproducibility of the flecainide test was 100%. In 4 (18%) of 22 patients major VAs were documented after the end of flecainide infusion. VA occurred in 3 (43%) of 7 patients with, versus 1 (7%) 15 without SCN5A gene mutation (P < 0.05). No diagnostic ECG changes or arrhythmias developed in 25 control patients without structural heart disease who underwent the same study protocol. This study shows a high flecainide reproducibility, supporting its diagnostic value in Brugada syndrome. However, the occurrence of major VA, significantly higher in patients with documented SCN5A gene mutation, including in asymptomatic patients, mandates the performance under appropriate medical supervision. Whether a slower rate of drug infusion can lower the risk of VA induction, while maintaining the sensitivity of the test should be explored. (PACE 2003; 26[Pt. II]:338–341)
How to Program Pulse Duration or Tilt in Implantable Cardioverter Defibrillators
Authors: IRNICH WERNER
Published: December 2004

IRNICH, W.: How to Program Pulse Duration or Tilt in Implantable Cardioverter Defibrillators.
Implantable cardioverter defibrillators (ICDs) are available with independently programmable duration and tilt of the shock pulse waveform. Manufacturers do not, however, commonly advise how these parameters can be programmed for optimal clinical benefit. From theoretical considerations, the author recommends programming both parameters based on the measured lead system resistance R into which the shock is delivered. Assuming that the defibrillation pulse decline below the defibrillation threshold rheobase is undesirable because of the possibility of refibrillation. Mathematical relationships expressing optimal pulse duration and tilt as functions of the output time constant can be derived that are valid for monophasic pulses and the first phase of biphasic pulses. Two ICD manufacturers provide for programmable tilt (Medtronic GEM III, atrial channel) or both tilt T and pulse duration PD. (St. Jude Medical newest devices). Considering its output capacitance, it is recommended that the Medtronic Gem III should be programmed for

T = 50%

when

R < 75 Ω

and 65% when

R < 38 Ω

. The author considers programming tilt to 30% or 40% useless in clinical conditions. By the same reasoning, he recommends that the newer St. Jude Medical ICDs should be programmed to

T = 50%

if

R < 75 Ω

and 60% if

R < 41 Ω

, and

PD = 5.5, 5.0, 4.5, 4.0, 3.5

, and 3.0 ms for

R < 75, 73, 62, 51, 40

, and 32 Ω, respectively.

PD = 6 ms

was considered clinically unrealistic. Programmable shock pulse duration and tilt are useful in optimizing defibrillation, but it is suggested that this can best be accomplished by programming these parameters with the guidance of theory as described in this discussion. (PACE 2003; 26[Pt. II]:453–456)
Autonomic Denervation After the Maze Procedure
Authors: LÖNNERHOLM STEFAN , BLOMSTRÖM PER , NILSSON LEIF , ERICSON MATS , KESEK MILOS , JIDEUS LENA , BLOMSTRÖM‐LUNDQVIST CARINA
Published: December 2004

LÖNNERHOLM, S., et al.: Autonomic Denervation After the Maze Procedure.
The Maze III procedure is a surgical operation for curative treatment of AF. The procedure is extensive, however, with multiple incisions in both atria, and its effects on autonomic regulation of the heart rhythm are not known. This study comprises 17 patients, 10 with paroxysmal AF and 7 with chronic AF, who had no concurrent cardiac disease known to affect heart rate variability (HRV). A 24‐hour Holter recording was performed preoperatively and 2 months (early) and 7 months (late) after surgery, for analysis of HRV in the time and frequency domains. Early after the Maze procedure all HRV components were markedly reduced compared to baseline (mean ± 1 SD): SDNN

73 ± 13

versus

148 ± 50

(ms), total power

168 ± 126

versus

560 ± 1567

(ms2), low frequency (LF) power

47 ± 67

versus

826 ± 677

(ms2), high frequency (HF) power

47 ± 40

versus

678 ± 666

(ms2), and LF:HF

1.22 ± 0.9

versus

2.55 ± 1.4

. Late after the Maze procedure all variables were still reduced. Only total power increased significantly between early and late follow‐up (

168 ± 126

vs

496 ± 435

ms2). Late after Maze surgery, values of the different HRV components did not differ between the patients with paroxysmal AF and chronic AF. Early after the Maze procedure there is a marked decrease of all HRV components, which is maintained 7 months after surgery, a pattern consistent with denervation of the heart. (PACE 2003; 26[Pt. I]:587–592)
Use of Different Catheter Ablation Technologies for Treatment of Typical Atrial Flutter:
Authors: MARROUCHE NASSIR F. , SCHWEIKERT ROBERT , SALIBA WALID , PAVIA STEPHEN V. , MARTIN DAVID O. , DRESING THOMAS , COLE CHRISTOPHER , BALABAN KRYSZTOF , SAAD EDUARDO , PEREZ‐LUGONES ALEJANDRO , BASH DIANNA , TCHOU PATRICK , NATALE ANDREA
Published: December 2004

MARROUCHE, N.F., et al.: Use of Different Catheter Ablation Technologies for Treatment of Typical Atrial Flutter: Acute Results and Long‐Term Follow‐Up.
Objectives: We report the acute success and long‐term follow‐up in consecutive patients undergoing catheter ablation of typical right atrial flutter (AFL) using different ablation technologies. Methods: One hundred and two patients presenting for treatment of AFL to our laboratory were included in the study. Based on availability and physician preference, ablation was performed with either a cooled‐tip catheter (39 patients, group I), an 8‐ or 10‐mm tip catheter connected to a high‐power radiofrequency (RF) generator (25 patients, group II), or a 4‐ or 5‐mm tip catheter (38 patients, group III). Acute ablation success was achieved in all group II and group III patients. Among the 38 patients undergoing ablation with the conventional catheter tip (group I), crossover to an 8‐mm tip or a cooled tip ablation catheter was required in 11 patients (29%). The mean fluoroscopy time was significantly higher in group I

(54.3 ± 26.4 minutes)

when compared to group II

(39.6 ± 19.6 minutes; P < 0.05)

and group III

(40 ± 16 minutes; P = 0.0.5)
. After a mean follow up of20 ± 5months no patient in group II experienced recurrence of AFL, whereas 18.4% (7 of 38 patients;P < 0.05) in group I and 10% (4 of 39 patients;P < 0.05) in group III had recurrence of AFL. Ablation technologies designed to obtain larger size lesions appeared to be more effective in achieving acute ablation success of AFL and in limiting the long‐term recurrence rate of this arrhythmia. (PACE 2003; 26:743–746)
V‐A Block During Atrioventricular Nodal Reentrant Tachycardia:
Authors: GONZALEZ MARIO D. , CONTRERAS LEONARDO , CARDONA FRANCISCO , KLUGEWICZ CHRISTOPHER , ERGA KNUT S.
Published: December 2004

GONZALEZ, M.D., et al.: V‐A Block During Atrioventricular Nodal Reentrant Tachycardia: Reentry Confined to the AV Node.
Retrograde block during atrioventricular (AV) nodal reentrant tachycardia is considered a rare phenomenon that can potentially occur in the AV node or in the atrium. A patient with slow‐fast AV nodal reentrant tachycardia and transient VA block localized in the AV node is presented. Pharmacological and stimulation maneuvers identified the site of block in the AV node and not in the atrium. Thus, AV nodal reentry can be confined to the AV node. (PACE 2003; 26:775–777)
Torsades de Pointes and QT Prolongation Due to a Combination of Loratadine and Amiodarone
Authors: ATAR SHAUL , FREEDBERG NAHUM A. , ANTONELLI DANTE , ROSENFELD TIBERIO
Published: December 2004

ATAR, S., et al.: Torsades de Pointes and QT Prolongation Due to a Combination of Loratadine and Amiodarone.
Torsades de pointes (TdP) has not been previously reported with loratadine. A 73‐year old woman on chronic treatment with amiodarone for atrial fibrillation received loratadine and presented with syncope and multiple episodes of TdP. We suggest that QT interval should be monitored whenever loratadine is co‐administered with drugs that may potentially prolong QT. (PACE 2003; 26:785–786)
A comparison between local anaesthetic dorsal nerve block and caudal bupivacaine with ketamine for paediatric circumcision
Authors: Gauntlett Ian
Published: December 2004

Background: Ketamine has been shown to prolong analgesia produced by caudal local anaesthetic block and is now in common use. This study compares caudal block using bupivacaine/ketamine with dorsal nerve block of the penis.

Methods: Sixty boys undergoing elective circumcision were given either 0.5 ml·kg−1 of bupivacaine 0.15% with ketamine 0.5 mg·kg−1 (n = 30) or dorsal nerve block of the penis with bupivacaine 0.5% (n = 30) as a supplement to general anaesthesia. Postoperative pain was assessed by parents using a modified objective pain score, and the time taken to first requirement of analgesia was recorded. Motor weakness, time to first micturition, postoperative nausea and vomiting (PONV), eating habits, sleep disturbance and behaviour were also assessed.

Results: There was no difference between the groups in time to first requirement for analgesia or number of doses of paracetamol given in the first 24 h. Almost half the boys in the caudal group had motor weakness, and there was a significant increase in time to first micturition in that group. There was no difference between the groups in PONV, eating, sleeping or behavioural disturbance.

Conclusions: Caudal anaesthesia with bupivacaine/ketamine does not confer any advantage over a dorsal nerve block with the doses used in this study. Because of the higher incidence of side‐effects and technique failure in the caudal group, dorsal nerve block is perhaps the preferred technique.
The effectiveness and safety of spinal anaesthesia in the pyloromyotomy procedure
Authors: Somri Mostafa , Gaitini Luis A. , Vaida Sonia J. , Malatzkey Shelton , Sabo Edmond , Yudashkin Marina , Tome Riad
Published: December 2004

Background: Hypertrophic pyloric stenosis is a relatively common disorder of the gastrointestinal tract in infancy, causing projectile vomiting and metabolic abnormalities. Surgical management in the form of pyloromyotomy under general anaesthesia has been reported as safe for relieving the obstructed bowel. A number of studies have demonstrated the advantages of spinal anaesthesia over general anaesthesia in high risk infants undergoing minor infraumbilical surgery. The purpose of this study was to evaluate spinal anaesthesia as an alternative option to general anaesthesia in infants undergoing pyloromyotomy.

Methods: Twenty‐five infants undergoing pyloromyotomy under spinal anaesthesia were studied. Haemodynamic and respiratory parameters were noted before performing the spinal block, 5 min after the spinal block, and every 10 min after performing the spinal block; for a total period of 30 min. The spinal block was performed using spinal isobaric bupivacaine 0.5%, 0.8 mg·kg−1. Blood pressure, heart rate, respiratory rate and oxygen saturation values were recorded.

Results: The sensory levels achieved ranged between T3–T5 thoracic segments within 6–8 min and were sufficient to perform surgery in 23 cases. There were no statistically significant differences in the oxygen saturation, systolic blood pressure and respiratory rate compared with before the spinal block and after 5, 10, 20 and 30 min.

Conclusions: This study proposes that spinal anaesthesia is an alternative option to general anaesthesia in infants undergoing pyloromyotomy, and should be considered in infants undergoing pyloromyotomy.
Caudal bupivacaine and s(+)‐ketamine for postoperative analgesia in children
Authors: Weber Frank , Wulf Hinnerk
Published: December 2004

Summary Background: The aim of this study was to evaluate whether caudal s‐ketamine would prolong analgesia together with caudal bupivacaine.

Methods: Thirty children, ASA I–II, 1 month−9 years, scheduled for minor inguinal or penile surgery, were randomly assigned in a prospective, double‐blind fashion to receive single shot caudal blockade by either bupivacaine 0.125% 1 ml·kg−1 (group B, n = 15) or a mixture of bupivacaine 0.125% 1 ml·kg−1 and preservative‐free s‐ketamine 0.5 mg·kg−1 (group K, n = 15). Postoperative pain was assessed by means of an observational 10‐point scoring system and analgesia was administered if the pain score exceeded a value of 3.

Results: Within 24 h after caudal block 10 patients (67%) in group K and three patients in group B (20%) did not require additional analgesic medication (P < 0.01). There were no significant differences between the groups for incidence of haemodynamic changes. We did not observe any negative side‐effects attributable to the caudal block or s‐ketamine.

Conclusions: Addition of preservative‐free s‐ketamine 0.5 mg·kg−1 to caudal bupivacaine 0.125% 1 ml·kg−1 provides significant prolongation of analgesia without producing negative side‐effects.
Dose response study of caudal neostigmine for postoperative analgesia in paediatric patients undergoing genitourinary surgery
Authors: Batra Y.K. , Arya V.K. , Mahajan R. , Chari P.
Published: December 2004

Background: Neostigmine given through the neuraxial route has been found to have analgesic properties. In this clinical trial, we evaluated for the first time the efficacy of a varying dose of caudal neostigmine for postoperative analgesia in children undergoing genitourinary surgery.

Method: In this double blind prospective study, we studied 120 children ASA physical status I in age group of 2–8 years scheduled for surgical repair of hypospadias under general anaesthesia. Children were randomly allocated to one of the six groups (n = 20 each) and received either no caudal block (group C) or neostigmine (groups I‐V) in doses of 10, 20, 30, 40 and 50 μg·kg−1 respectively at the end of the surgery. Postoperatively pain was assessed using an objective pain score for 24 h. Blood pressure, heart rate, SpO2, total amount of analgesic consumed and adverse effects, if any, were also recorded.

Result: The duration of postoperative analgesia did not differ significantly between group C and I (P > 0.05). There was significant prolongation in the duration of analgesia in rest of the groups (group II‐3.52 ± 1.37 h; group III‐6.50 ± 1.93 h; group IV‐10.45 ± 3.41 h; group V‐13.70 ± 5.52 h) (P < 0.05). A dose dependent increase in the incidence of nausea and vomiting was also observed with highest incidence in group IV and V (group C‐15%; group I‐20%; group II and III‐30%; group IV‐45% and group V‐60%) (P < 0.05). No significant alteration in vital signs and other adverse effects were noticed.

Conclusion: Caudal neostigmine in the dose range of 20–50 μg·kg−1 provides dose dependent analgesia. However, dose exceeding 30 μg·kg−1 is associated with a higher incidence of nausea and vomiting.
Anaesthetic management of a patient with achondroplasia
Authors: Krishnan B.S. , Eipe Naveen , Korula Grace
Published: December 2004

Summary A 12‐year‐old girl diagnosed with achondroplasia was admitted for bilateral ear surgery and adenotonsillectomy. She had classical symptoms and signs of upper airway obstruction, which is often seen in patients with achondroplasia. We describe the anaesthetic management of this patient, emphasizing the airway difficulties encountered and their anaesthetic implications.
Incidence of vomiting in susceptible children under regional analgesia with two different anaesthetic techniques
Authors: Sarti A. , Busoni P. , Dell'Oste C. , Bussolin L.
Published: December 2004

Background:  Postoperative vomiting (POV) is a frequent side‐effect of paediatric surgery and a leading cause of unplanned admission. Many antiemetic drugs have been studied, but less attention has been given to the effects on POV of the anaesthetic technique adopted. The aim of this study was to compare two different anaesthetic techniques in children under regional analgesia at risk for POV.

Methods:  We studied 135 children suffering from motion sickness or with a previous history of POV. The patients were randomized to receive inhalation anaesthesia (group S) with sevoflurane by LMATM or intravenous (i.v.) anaesthesia with ketamine and propofol (group P). All the patients were treated with an ilio‐inguinal block after induction of anaesthesia. Postoperatively, the children were followed by the nursing staff and by their parents, none of whom were aware of the anaesthesia technique used.

Results:  A significant decrease was observed in the incidence of early (0–6 h) and delayed (6–24 h) POV in those children who received i.v. sedation. There was no difference between the two groups in the level of analgesia either at the end of surgery or 2 h postoperatively.

Conclusions:  Anaesthesia based on propofol and ketamine is better than inhalation anaesthesia with sevoflurane by LMA for reducing POV in children at risk under an ilio‐inguinal block. Tailoring the anaesthetic to the specific needs of children susceptible to POV should be considered before resorting to the routine use of expensive antiemetic prophylaxis.
The effect of environmental tobacco smoke on the dose requirements of rocuronium in children
Authors: Reisli Ruhiye , Apilliogullari Seza , Reisli Ismail , Tuncer Sema , Erol Atilla , Okesli Selmin
Published: December 2004

Background:  Smoking affects the pharmacodynamic and pharmacokinetic behaviour of several drugs. The aim of this study was to evaluate the effects of environmental tobacco smoke on onset and recovery time after single dose rocuronium in children.

Methods:  Forty children between 4 and 10 years were enrolled into the study. Children who have no familial smoking history were included in the first group whereas passive smokers included in the second group. Sevoflurane in 50% O2 and 50% N2O was used for induction of anaesthesia. Evoked adductor pollicis electromyography was used to monitor neuromuscular block. The T95 and T25 values were recorded.

Results:  The T95 values (±sd) for rocuronium were 110.1 ± 39.3 s and 79.3 ± 35.6 s for group 1 and group 2, respectively (P < 0.05). The T25 value of group 2 was 40.1 ± 10.6 min and compared with group 1 values (30.85 ± 7.02 min) it was significantly longer (P < 0.01).

Conclusion:  This study shows that passive smoking children consume less rocuronium than nonsmokers during similar anaesthesia. We think that a history of passive smoking must also be taken into consideration during preoperative evaluation of paediatric patients.
Anaesthetic implications of LEOPARD syndrome
Authors: Torres Javier , Russo Pierantonio , Tobias Joseph D.
Published: December 2004

LEOPARD syndrome is a neuroectodermal disorder presumed to result from an abnormality in neural crest cells. The acronym ‘LEOPARD’ is derived from the clinical features which include multiple lentigines, electrocardiographic abnormalities, ocular hypertelorism, pulmonary stenosis, abnormal genitalia, retarded growth, and deafness. Given the multisystem nature of the disease process, several issues may affect the perioperative care of these patients. Of primary importance are associated conditions of the cardiovascular system including congenital heart disease, conduction disturbances, and progressive hypertrophic obstructive cardiomyopathy. The authors present a 4‐year old boy who presented for anaesthetic care for repair of a ventricular septal defect and pulmonary valvotomy for congenital pulmonary stenosis. The potential perioperative implications of LEOPARD syndrome are discussed.
Providing parents with information before anaesthesia: what do they really want to know?
Authors: Wisselo Tirzah L. , Stuart Catherine , Muris Peter
Published: December 2004

Background : Videotapes presenting information concerning children's anaesthesia are often based on what the makers of the videotape believe the parents want to know rather than what parents actually want to know. They frequently do not take into account the parent's coping style. Two common parental coping styles are information‐seeking (monitoring) and information‐avoiding (blunting).

Methods : We wished to take parent needs into account when making our local videotape and accordingly constructed a questionnaire designed to elicit these needs.

Results : Of the parents questioned, 55% wanted more extensive preoperative information and 41% of parents wanted a videotape as part of this preparation. Information about premedication, induction of anaesthesia, side‐effects of anaesthesia and postoperative pain management were sought by more than 70% of parents. Parents had concerns about induction of anaesthesia, emergence from anaesthesia and postoperative pain and nausea. When asked a question concerning preference about being present at the induction of anaesthesia, 90% of parents wanted to be present at the induction and 75% of parents thought that their child should receive a premedicant. The number of parents requesting to be present at the induction decreased to 72% after an explanation about the purpose and effects of premedication. There was no correlation between the coping style of the parent and the responses given to the questions. There was no correlation between the level of education and the coping style of the parent.

Conclusions : The use of a questionnaire of parental attitudes towards information and anaesthesia provided a useful tool in the production of a video as part of our preoperative preparation. Our videotape has proved a success with staff and parents and children and enhances the quality of our service. Its popularity stems from the fact that it addresses what the parents want to know and also conveys what the staff of this hospital would like the parents to know.
Atrial Pacing Lead Location Alters the Hemodynamic Effects of Atrial‐Ventricular Delay in Dogs with Pacing Induced Cardiomyopathy
Authors: HETTRICK DOUGLAS A. , MITTELSTADT JACQUELINE R. , KEHL FRANZ , KRESS TOBIAS T. , TESSMER JOHN P. , KROLIKOWSKI JOHN G. , KERSTEN JUDY R. , WARLTIER DAVID C. , PAGEL PAUL S.
Published: December 2004

HETTRICK, D.A., et al.: Atrial Pacing Lead Location Alters the Hemodynamic Effects of Atrial Ventricular Delay in Dogs with Pacing Induced Cardiomyopathy.
The role of atrial lead location in cardiovascular function in the presence of impaired ventricular dysfunction is unknown. We tested the hypothesis that left atrial (LA) and left ventricular (LV) hemodynamics are affected by alterations in AV delay and are influenced by atrial pacing site in dogs with dilated cardiomyopathy. Dogs

(n = 7)

were chronically paced at 220 beats/min for 3 weeks to produce cardiomyopathy and then instrumented for measurement of LA, LV end diastolic pressure (LVEDP) and mean arterial pressure (MAP), LA volume, LV short‐axis diameter, and aortic and pulmonary venous blood flow. Hemodynamics were measured after instrumentation and during atrial overdrive pacing from the right atrial appendage (RAA), coronary sinus ostium (CSO) and lower LA lateral wall (LAW). The AV node was then ablated, and hemodynamics were compared during dual chamber AV pacing (right ventricular apex) from each atrial lead location at several AV delays between 20 and 350 ms. Atrial overdrive pacing from different sites did not alter hemodynamics. Cardiac output (CO), stroke volume, LVEDP, MAP and +dLVP/dt demonstrated significant (P < 0.05) variation with AV delay during dual chamber pacing. CO was higher during LAW pacing than RAA and CSO pacing (

2.3 ± 0.4

vs

2.1 ± 0.3

vs

2.0 ± 0.3 l/min

, respectively) at an AV delay of 120 ms. Also, MAP was higher in the LAW than RAA and CSO (

65 ± 9

vs

59 ± 9

vs

54 ± 11 mmHg

, respectively) at an AV delay of 350 ms. Atrial lead location affects indices of LV performance independent of AV delay during dual chamber pacing in dogs with cardiomyopathy. (PACE 2003; 26[Pt. I]:853–861)
Prolonged Ventricular Asystole, Sinus Arrest, and Paroxysmal Atrial Flutter‐Fibrillation:
Authors: CHOU HSIN‐HUA , LIN KUO‐HUNG , LUQMAN NAZAR , KUO CHI‐TAI
Published: December 2004

CHOU, H.‐H., et al.: Prolonged Ventricular Asystole, Sinus Arrest, and Paroxysmal Atrial Flutter‐Fibrillation: An Uncommon Presentation of Vasovagal Syncope.
We described a 55‐year‐old woman with recurrent syncope, complete atrioventricular (AV) block, sparsely scattered idioventricular beats lasting for 56 seconds, and long sinus arrest recorded during the syncopal episode. Paroxysmal atrial flutter‐fibrillation was also presented during Holter electrocardiograph (ECG) monitoring without clinical symptom. During tilt test, atrial flutter with variable AV block was induced and the patient suddenly passed out. The vasovagal syncope was successfully treated with a DDD permanent pacemaker with a rate drop response algorithm. Vasovagal syncope with concomitant ventricular asystole and sinus arrest is rare. Aggressive management with permanent pacemaker is strongly advocated in malignant vasovagal syncope. (PACE 2003; 26[Pt. I]:914–917)
Induction Ovens and Electromagnetic Interference:
Authors: RICKLI HANS , FACCHINI MARCO , BRUNNER HANSPETER , AMMANN PETER , SAGMEISTER MARKUS , KLAUS GEORG , ANGEHRN WALTER , LUECHINGER ROGER , DURU FIRAT
Published: December 2004

Electromagnetic fields may interfere with normal pacemaker function. Despite the introduction of modern pacemakers and bipolar lead systems, electromagnetic interference (EMI) still remains to be a concern during daily lives when patients are exposed to cellular phones, electronic security systems, and several household appliances. The aim of this study was to evaluate potential EMI risk of induction ovens, which are increasingly used in private households. The study included 40 consecutive patients (22 men, 18 women; age

73 ± 11  years

) with implanted DDD, VVI, VDD, and AAI pacemaker systems. The pacemakers were programmed to unipolar sensing and pacing. Sensitivity remained unchanged, if the measured sensing threshold was more than twice the programmed value; otherwise, it was set at half of the measured sensing threshold. Patients were placed in a sitting position at the closest possible distance of about 20 cm between two cooking pots and pacemaker bending the upper part of the body slightly over the induction oven. The energy was increased stepwise to the maximum. One pot was removed and placed again at the highest oven level. Potential interference was monitored continuously. The study showed no incidence of pacemaker malfunction during the entire test while the patients with intrinsic cardiac rhythms were exposed to the induction oven at varying energy strengths. Likewise, there was no external interference when the patients were paced at heart rates of 10–15 beats/min above their heart rates. The programmed parameters remained unchanged after the study. In conclusion, this study shows no EMI risk of an induction oven in patients with bipolar or right‐sided unipolar pacemakers. (PACE 2003; 26[Pt. I]:1494–1497)
Temporary Transvenous Pacing with an Active Fixation Bipolar Lead in Children:
Authors: PINTO NELANGI , JONES THOMAS K. , DYAMENAHALLI UMESH , SHAH MAULLY J.
Published: December 2004

Various techniques and electrode catheters have been developed for effective and safe temporary transvenous cardiac pacing. In neonates and children, lead dislodgment and myocardial perforation have been attendant risks with passive fixation leads. We report our experience with the recently introduced Medtronic 6416 active fixation bipolar lead in a small group of children. Between January 2000 and February 2002, 4 children (2 boys, 2 girls) underwent temporary transvenous pacing with the Medtronic 6416 lead. The median age at implantation was 4.25 years (range: 5 days–13 years), median weight was 14.5 kg (range: 2.5 kg–54 kg) and the median duration of temporary pacing was 19.5 days (range: 5–38 days). The indication for temporary pacing was AV block (n = 2), sinus arrest (n = 1) and sinus node dysfunction (n = 1). The acute pacing threshold was <1.5 mA with no significant rise in the follow‐up period. The venous access for lead placement was femoral vein (n = 2), internal jugular vein (n = 1), and subclavian vein (n = 1). There were no complications related to implantation or in the follow‐up period. The Medtronic 6416 lead appears to be a safe and effective tool in temporary transvenous pacing in neonates and children. (PACE 2003; 26[Pt. I]:1519–1522)
New Trial Data on Prevention: Potassium and CV Risk in Hope
Authors: Mann Johannes F. E. , Yi Qi‐Long , Sleight Peter , Dagenais Gilles R. , Probstfield Jeff , Gerstein Hertzel C. , Lonn Eva M. , Bosch Jackie , Yusuf Salim ,   HOPE investigators
Published: December 2004

Introduction: Hypokalaemia may be hazardous. Methods: Potassium was measured in 9,297 patients in HOPE, & was <3.5 in 137. Results: The combined primary outcome (cardiovascular death, myocardial infarction, or stroke) increased with hypokalemia (22.6% vs 15.5%, p 0.023, hazard ratio 1.44). Hyperkalemia conferred no hazard Hypokalemia was more prevalent in women, in hypertensives, & with diuretics. Ramipril benefit was independent of potassium. Less patients on ramipril had hypokalaemia (p = 0.005), including those on diuretics (3.8% v 6.5%, p = 0.07). Conclusion: In high risk people hypokalemia increased the risk for cardiovascular events, while hyperkalemia did not. Ramipril was not associated with increased risk with hyperkalemia, but mitigated the diuretic induced risk of hypokalaemia; the latter may increase with increased diuretic use after ALLHAT. A diuretic/ACE‐Inhibitor combination appeared safe, & may be even more popular after the ANBP‐2 trial, which contrary to ALLHAT favoured an ACE‐I over a thiazide. HPS & ASCOT favour statins in addition.
Noncircadian oscillations in amino acid transport have complementary profiles in assimilatory and foraging hyphae of Phanerochaete velutina
Authors: Tlalka M. , Hensman D. , Darrah P. R. , Watkinson S. C. , Fricker M. D.
Published: December 2004

Cord‐forming woodland basidiomycete fungi form extensive, interconnected mycelial networks that scavenge nitrogen (N) efficiently. We have developed techniques to study N dynamics in such complex mycelial systems in vivo.

Uptake and distribution of the nonmetabolised, 14C‐labelled amino‐acid analogue, α‐aminoisobutyrate (14C‐AIB) was continuously imaged in Phanerochaete velutina growing across scintillation screens using an enhanced photon‐counting camera.

Oscillations in the 14C‐AIB signal were observed for both the assimilatory hyphae in the inoculum and the foraging hyphae, but with complementary profiles. Pulses were asymmetric, with an abrupt switch between each exponential decay phase and the next rising phase. The period of the oscillations was 16 h at 21°C, but showed a strong temperature dependence with a temperature coefficient of 2.1. Oscillations occurred in the absence of obvious pulses in growth.

Some, but not all, of the features of the oscillations were simulated using a model of amino acid accumulation and transport that included both vacuolar uptake, and release once an intravacuolar concentration threshold was exceeded. The combination of imaging and modelling provides a useful framework to understand N fluxes in vivo.
Components of leaf elongation rate and their relationship to specific leaf area in contrasting grasses
Authors: Arredondo J. Tulio , Schnyder Hans
Published: December 2004

In grasses the leaf growth zone is the main site of shoot growth where anatomical and chemical characteristics of leaves originate. Yet, there is insufficient information to generalize as to whether the leaf growth zone reflects habitat characteristics, whether leaf growth traits are regularly interrelated, and whether they coincide with characteristics of mature leaves.

Here the contribution of both length of the leaf growth zone (region where cell division and expansion occurs) and relative elemental growth rate to the variability in leaf elongation rate (LER) were examined in eight grass species from habitats with different soil fertility. Further, we examined the relationship of the above traits with specific leaf area (SLA) and its components.

Growth zone length differed significantly among species (P < 0.05) and it was the trait contributing the most to LER. Using LER and derived components it was possible to classify seven out of eight species into two groups related to soil fertility. Leaf elongation rate exhibited a positive correlation to SLA and a negative correlation to leaf dry matter content. A significant relationship existed between size of the growth zone and leaf dry matter content.

The results suggest that the leaf growth zone is a critically important leaf trait that explains inherent differences in LER and other plant characteristics of grass species.
Signalling through cyclic nucleotide monophosphates in cyanobacteria
Authors: Cann Martin J.
Published: December 2004

The cyanobacteria are a diverse group of photosynthetic prokaryotes, of which many species synthesize cyclic nucleotide monophosphates. The role of cyclic nucleotide monophosphates in cyanobacterial biology has been studied through phenotypic, molecular, genetic, and computer‐based analyses and here I review the history of the field. The study of cyclic nucleotide monophosphates in cyanobacteria has been informed by experiments performed in unrelated organisms but recent investigations have, however, demonstrated that scientific principles, applicable to a wide range of species, can be derived from the study of cyclic nucleotide biology in cyanobacteria and I detail some of this work.

Contents

Summary
23

I.
Introduction
23

II.
Cyclic nucleotide monophosphates
24

III.
cNMPs and their roles in cyanobacteria
26

IV.
Molecular identification of components of the cNMP signalling pathway in cyanobacteria
27

V.
Lessons from cAMP signalling in cyanobacteria for other organisms
30

Acknowledgements
31

References
32
Natural selection inIpomopsishybrid zones: implications for ecological speciation
Authors: Campbell Diane R.
Published: December 2004

The fitness of hybrids relative to parental species plays an important role in models of speciation. In ecological speciation, reproductive isolation evolves owing to divergent natural selection, which implies reduced fitness of hybrid phenotypes. The source of the divergent selection in flowering plants may be animal pollinators, or environmental features of habitats that lead to physiological adaptations. Reciprocal transplants, combined with examination of pollination and other fitness components, allow exploration of these mechanisms of speciation. Much of this information is available from hybrid zones betweenIpomopsis aggregataandIpomopsis tenuituba. Pollination studies reveal some disruptive selection on corolla width, but also geographical variation in pollinator preference, and hybrids do not generally suffer lower pollination. Survival of hybrids depends on both genotype and environment. One genotypic class of hybrids is as fit or more fit than the parents, while another type suffers reduced fitness in parental environments. The dynamics of this hybrid zone involve a complex mixture of selection mediated by pollinators and other sources, and this combination of selection may have contributed to the original speciation.
Ivermectin and filariasis
Authors: Richard‐Lenoble Dominique , Chandenier Jacques , Gaxotte Philippe
Published: December 2004

Ivermectin, a parasiticide that long ago proved its worth in veterinary medicine, became one of the most effective tools for control programs against human filarial diseases in the 1980s. It is provided at no cost, is effective against microfilariae (blocking their transmission) and can be administered annually as a single oral dose with virtually no side‐effects: these considerations led the WHO to officially declare eradicable two endemic filarial diseases (among the major endemic diseases worldwide), onchocerciasis and lymphatic filariasis.
Prenatal Exclusion of Ehlers‐Danlos Syndrome Type VI by Mutational Analysis
Authors: Yeowell Heather N. , Walker Linda C.
Published: December 2004

We have performed the first prenatal assessment of clinical phenotype in a family affected by Ehlers‐Danlos syndrome type VI (EDS VI), an inherited collagen disorder, by screening the fetal DNA for mutations in the lysyl hydroxylase (LH) gene. We have previously reported that the affected child in this family is compound heterozygous for mutations in the LH gene. One allele has a paternally inherited C1557 to G change that codes for a premature stop codon (Y511X) in exon 14 and the other allele has a deletion of exon 5 that results from a maternally inherited mutation in the consensus donor splice site of intron 5. To perform the prenatal diagnosis, we sequenced genomic DNA isolated from cultured chorionic villus cells at 10 weeks of gestation. One allele had the maternally inherited gt →at splice‐site mutation in exon 5, and the other paternally inherited allele was normal. As EDS VI is a recessive disorder, we predicted that although a carrier, the baby should be unaffected. This conclusion, which was supported by a normal level of LH activity in the chorionic villus cells, was confirmed by the birth of a healthy unaffected baby.
Making Sense of Medical Marijuana
Authors: Rosenthal Mitchell S. , Kleber Herbert D.
Published: December 2004

The case for marijuana’s medical use is primarily from anecdotal clinical reports, human studies of delta‐9‐tetrahydrocannabinol, and animal studies on constituent compounds. The authors believe that while a key policy issue is to keep marijuana out of the hands of children, its use for medicinal purposes should be resolved by scientific research and Food and Drug Administration (FDA) review. Weighed against possible benefits are increased risks such as cancer, pulmonary problems, damage to the immune system, and unacceptable psychological effects. More study is needed to determine the efficacy of marijuana as an antiemetic for cancer patients, as an appetite stimulant for AIDS and cancer patients, as a treatment for neuropathic pain, and as an antispasmodic for multiple sclerosis patients. If this new research shows marijuana to have important medical uses, FDA approval could be sought. However, the better response is accelerated development of delivery systems other than smoking for key ingredients, as well as the identification of targeted molecules that deliver beneficial effects without intoxicating effects. If the National Institutes of Health conducts research on marijuana, we would propose parallel trials on those indications under careful controls making marijuana available to appropriate patients who fail to benefit from standard existing treatments. This effort would begin after efficacy trials and sunset no later than 5 years. If this open‐trial mechanism is adopted, the compassion that Americans feel for seriously ill individuals would have an appropriate medical/scientific outlet and not need to rely on referenda that can confuse adolescents by disseminating misleading information about marijuana effects.
Examining the Debate on the Use of Medical Marijuana
Authors: DuPont Robert L.
Published: December 2004

The opium poppy and the coca leaf offer useful perspectives on the current controversies over medical marijuana. In both cases, purified synthetic analogues of biologically active components of ancient folk remedies have become medical mainstays without undermining efforts to reduce nonmedical drug use. A decade ago, a campaign strove to legalize heroin for the compassionate treatment of pain in terminally ill patients. Like the current campaign to legalize medical marijuana, many well‐meaning people supported this effort. The campaign for medical heroin was stopped by science when double‐blind studies showed that heroin offered no benefits over the standard opioid analgesics in the treatment of severe cancer pain.

Scientific medicine requires purified chemicals in carefully controlled doses without contaminating toxic substances. That a doctor would one day write a prescription for leaves to be burned is unimaginable. The Controlled Substances Act and international treaties limit the use of abused drugs or medicines. In contrast to smoked marijuana, specific chemicals in marijuana or, more likely, synthetic analogues, may prove to be of benefit to some patients with specific illnesses. Most opponents of medical use of smoked marijuana are not hostile to the medical use of purified synthetic analogues or even synthetic tetrahydrocannabinol (THC), which has been available in the United States for prescription by any licensed doctor since 1985. In contrast, most supporters of smoked marijuana are hostile to the use of purified chemicals from marijuana, insisting that only smoked marijuana leaves be used as “medicine,” revealing clearly that their motivation is not scientific medicine but the back door legalization of marijuana.
Characterization of a Multicopy Family of Genes Encoding a Surface‐Expressed Serine Endoprotease in Rat Pneumocystis carinii
Authors: Russian David A. , Andrawis‐Sorial Vivian , Goheen Michael P. , Edman Jeffrey C. , Vogel Peter , Turner Ross E. , Klivington Diane L. , Angus C. William , Kovacs Joseph A.
Published: December 2004

A unique family of genes encoding serine endoproteases related to the Saccharomyces cerevisiae serine endoprotease kexin was identified in Pneumocystis carinii. Unlike previously described serine endoprotease genes that are single copies, multiple copies of the P. carinii serine endoprotease are distributed throughout the genome. The proteins predicted by these variant genes demonstrate sequence variability, but they retain the conserved active sites associated with endoprotease activity. The serine endoprotease was localized to the organism surface by immunohistochemical and immunofluorescence studies and to the electron lucent layer of the cyst wall by immunoelectron microscopy. The findings of multiple copies of the serine endoprotease gene in the P. carinii genome, and its localization to the cell surface, suggest that this protease plays an important role in the biology of P. carinii and that antigenic variation of the surface‐expressed serine endoprotease may be a strategy for immune evasion. P. carinii serine endoprotease provides a novel target for chemotherapeutic and immune‐based approaches to the treatment of P. carinii pneumonia.
Transduction of a Preselected Population of Human Epidermal Stem Cells: Consequences for Gene Therapy
Authors: Bickenbach Jackie R. , Roop Dennis R.
Published: December 2004

Continuously renewing tissues, such as the epidermis, are populated by a hierarchy of dividing transient amplifying cells, which are maintained by stem cells. Transient amplifying cells divide to maintain the tissue, but they are limited to a finite number of cell divisions before they differentiate and are sloughed. Only the stem cells remain for the life of the tissue. Thus, it is critical to target stem cells when designing gene therapy regimes for genetically inherited diseases, such as epidermolysis bullosa simplex (EBS). Unfortunately, isolating pure epithelial stem cells has been problematic. In this study, we used rapid adherence to collagen type IV to successfully enrich for epidermal stem cells from adult human skin. These preselected stem cells were slow to proliferate, but they ultimately formed large colonies. When recombined with the dermal substrate AlloDerm, the stem cells re‐formed a stratified squamous epidermis within 1 week after raising the AlloDerm to the air‐liquid interface. These organotypic cultures grew continuously and, even after 6 weeks in culture, they maintained a proliferative basal layer. When transduced with a retroviral LacZ vector, preselected stem cells formed β‐galactosidase‐positive clones in submerged and organotypic cultures. Transduced cells showed persistent expression through 12 weeks in organotypic culture, demonstrating the feasibility of using preselected stem cells for gene therapy. Currently, we are developing two models of EBS to test a gene therapy approach, which is based on the premise that EBS stem cells with a mutant keratin (K)14 gene corrected to wild type will have a growth advantage over noncorrected EBS stem cells.