bluuebunny/crossref_metadata_2025 huggingface dataset:
Telomerase activity in renal cell carcinoma by modified telomeric repeat amplification protocol assay
Authors: Segawa Naoki , Gohji Kazuo , Azuma Haruhito , Iwamoto Yusaku , Ohnishi Kenji , Katsuoka Yoji
Published: December 2004

Background: Previous assessments by the conventional telomeric repeat amplification protocol have not been reliable for the quantitation of telomerase activity. We, therefore, determined telomerase activity in renal cell carcinoma (RCC) tissue by the modified sensitive telomeric repeat amplification protocol assay.

Methods: Telomerase activity was examined in 23 cases of RCC and in the adjacent normal kidney tissue, and assessed for associations with clinical and pathological variables of the disease.

Results: The linearity and quantitation of the modified method was confirmed. Mean telomerase activity of RCC (1987.889 ± 1232.801 units) was significantly greater than that of normal renal tissue (173.467 ± 241.893 units) (P = 0.0001). Telomerase activity in RCC was, however, not associated with clinical or pathological variables such as clinical stage (P = 0.8941), grade (P = 0.8043) or pathological subtype (P = 0.9739).

Conclusion: The results suggest that telomerase might play a crucial role in an initial step of the development of RCC, but not in the progression of the disease.
Predicting disease outcome of non‐invasive transitional cell carcinoma of the urinary bladder using an artificial neural network model: Results of patient follow‐up for 15 years or longer
Authors: Fujikawa Keita , Matsui Yoshiyuki , Kobayashi Takashi , Miura Katsuki , Oka Hiroya , Fukuzawa Shigeki , Sasaki Miharu , Takeuchi Hideo , Okabe Tatsushiro
Published: December 2004

Background: Patients with non‐invasive (Ta/T1) transitional cell carcinoma (TCC) of the urinary bladder are often observed without progression in the long‐term follow‐up period, although many of them experience recurrence of disease. It is difficult to accurately predict the disease outcome of each patient with Ta/T1 TCC using conventional prognostic criteria. In this study, we examined the usefulness of artificial neural networks (ANNs) to predict the long‐term disease outcome of patients with TCC of the urinary bladder.

Methods: A retrospective, prognostic study of 90 patients with Ta/T1 TCC of the urinary bladder, diagnosed by transurethral resection of the bladder tumor between April 1981 and March 1985, and then followed up for 15 years or longer, was carried out. Data were analyzed using the Bayesian network tool of SPSS Neural Connection 2.1. The input neural data consisted of tumor stage, grade, tumor number, age, gender, tumor architecture and estimates of mean nuclear volume. The data set was randomly divided into 68 training and 22 testing examples for the prediction of disease progression and tumor recurrence within 15 years.

Results: During 15 years follow‐up, tumor recurrence was noted in 42/90 (47%) Ta/T1 tumors. The ANN model could not predict tumor recurrence. Conversely, disease progression was noted in 17/90 (19%) Ta/T1 tumors, and, in the test set, 4/22 (18%) Ta/T1 tumors underwent disease progression. The sensitivity of the ANN model to predict progression was 100% (specificity 67%; positive predictive value 40%; negative predictive value 100%). Patients who were judged to have a favorable prognosis using ANN analysis did not progress within the 15‐year follow‐up period.

Conclusion: The results of the ANN study indicate that long‐term progression‐free survival of patients with non‐invasive TCC of the urinary bladder can be precisely predicted. A favorable prognosis using ANNs would be one of the exclusion criteria for immediate or future total cystectomy.
Postoperative morbidity, functional results and quality of life of patients following orthotopic neobladder reconstruction
Authors: Yoneda Tatsuaki , Igawa Mikio , Shiina Hiroaki , Shigeno Kazushi , Urakami Shinji
Published: December 2004

Aim: To evaluate postoperative morbidity, functional results and health‐related quality of life of patients with an orthotopic neobladder.

Methods: A total of 37 patients with orthotopic neobladder (modified Studer method: 35 cases; Hautmann method: one case; sigmoid neobladder: one case) were included in the present study. Postoperative morbidity and neobladder function were analyzed. To determine quality of life, the Sickness Impact Profile questionnaire was used. The quality of life of patients who underwent orthotopic neobladder was compared with that of patients who underwent ileal conduit.

Results: In 37 consecutive patients with neobladder reconstruction, early complications included 10 cases of pyelonephritis (27.0%) and one of stenosis of ureterointestinal anastomosis (2.7%). Two patients died of ARDS and sepsis following peritonitis and pneumonia in the perioperative period. Late complications included pyelonephritis in three patients (8.6%). In 32 cases, except for an early postoperative case and those that died, complete daytime and night‐time continence was achieved in 31 patients (96.9%) and 16 patients (50.0%), respectively. Concerning health‐related quality of life, the mean sum scores per category of the Sickness Impact Profile were calculated for 32 patients with orthotopic neobladder and 30 patients with ileal conduit. There were no significant differences in overall satisfaction, however, the scores for patients with orthotopic neobladder reconstruction were significantly higher than those for patients with ileal conduit in the three categories of emotions, feelings and sensation, social interaction and recreation.

Conclusion: Orthotopic neobladder reconstruction exhibited good functional results with acceptable complications. Patients who underwent neobladder reconstruction were satisfied with their voiding. Assessment of quality of life using the Sickness Impact Profile questionnaire demonstrated that orthotopic neobladder improved their quality of life better than ileal conduit, especially with regard to mental, physical and social functioning in daily life.
Pathological effects of neoadjuvant hormonal therapy help predict progression of prostate cancer after radical prostatectomy
Authors: KITAGAWA YASUHIDE , KOSHIDA KIYOSHI , MIZOKAMI ATSUSHI , KOMATSU KAZUTO , NAKASHIMA SHINICHI , MISAKI TOSHIMITSU , KATSUMI TETSUO , NAMIKI MIKIO
Published: December 2004

Background: It is not clear whether pathological changes following neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy have any value as predictors of progression in prostate cancer.

Methods: We conducted a study of 100 patients with prostate cancer who underwent radical prostatectomy following NHT. We used the Japanese general rule as the criterion to assess the biochemical recurrence rate and pathological changes after NHT.

Results: In terms of preoperative risk factors, the probability of recurrence was significantly higher for patients with more than 20 ng/mL of pretreatment serum prostate‐specific antigen (PSA) and/or a Gleason score of 7 or higher for biopsy specimens. We defined these pretreatment findings as high‐risk factors. Among 65 patients with high‐risk factors, patients with a post‐NHT pathological effect of grade 3 according to the Japanese general rule showed no recurrence, whereas patients with a grade 0 had a poor prognosis. Patients with a PSA nadir 0.5 ng/mL or less tended to have a better prognosis.

Conclusion: Despite preoperative high‐risk factors, patients showing good pathological effects after NHT tend to have a favorable prognosis after radical prostatectomy. Therefore; assessment of the pathological effects of NHT using the Japanese general rule as the criterion proved to be useful for the prediction of biochemical recurrence.
Emphysematous pyelonephritis and renal amoebiasis in a patient with diabetes mellitus
Authors: GUVEL SEZGIN , KILINC FERHAT , KAYASELCUK FAZILET , TUNCER ILHAN , OZKARDES HAKAN
Published: December 2004

Emphysematous pyelonephritis is an uncommon and life‐threatening infection of the kidney that is characterized by gas formation within or around the kidney and is associated with diabetes mellitus and urinary tract infection. Amoebiasis is a protozoal infection caused by Entamoeba histolytica. In its invasive forms, the disease is characterized by visceral abscess formations. We present a case of concomitant emphysematous pyelonephritis and renal amoebiasis in a 42‐year‐old female with uncontrolled diabetes mellitus. The patient did not respond well to initial supportive treatment and antibiotherapy. Therefore, nephrectomy was performed. She did extremely well after the operation and was discharged with antidiabetics and antibiotics.
Pheochromocytoma of the urinary bladder without typical symptoms
Authors: ONISHI SAKATA TAKEHISA, YUKO , YONEMURA SHIGENORI , SUGIMURA YOSHIKI
Published: December 2004

Pheochromocytoma of the urinary bladder is an unusual tumor that typically presents with hypertensive crises related to micturition. We report, herein, the case of a 62‐year‐old woman with bladder pheochromocytoma. The patient presented with a bladder tumor that was incidentally found by computed tomography (CT) without the triad of sustained hypertension, hematuria and postmicturitional syncope. Cystoscopy revealed a yellowish submucosal tumor in the right lateral wall of the bladder. Treatment consisted of transurethral resection in the initial diagnosis of bladder tumor. A definitive diagnosis was made postoperatively upon pathological examination. The patient has been followed up for 12 months and has shown no recurrence.
Variations of transition zone volume and transition zone index after transurethral needle ablation for symptomatic benign prostatic hyperplasia
Authors: FUJIMOTO KIYOHIDE , HOSOKAWA YUKINARI , TOMIOKA ATSUSHI , YAMAMOTO HIROAKI , TANAKA YOZO , OTANI TAKESHI , OZONO SEIICHIRO , HIRAO YOSHIHIKO , HAYASHI YOSHIKI
Published: December 2004

Background: Transurethral needle ablation (TUNA) is less invasive than other therapies for benign prostatic hyperplasia (BPH) and produces coagulative necrosis within selected adenoma lesions. The action mechanism of TUNA is still obscure, even though many early studies have demonstrated good clinical results of TUNA. It is of interest and importance to know how TUNA influences the volume of the intraprostatic region responsible for bladder outlet obstruction in order to elucidate the anatomical action mechanism of TUNA.

Methods: We retrospectively investigated postoperative variations in volumetric parameters of whole prostate volume (PV), transition zone volume (TZV) and transition zone index (TZI = TZV/PV) in 41 patients with symptomatic BPH who were treated with TUNA. The data were analyzed statistically in relation to the preoperative overall severity and postoperative therapeutic efficacy.

Results: Both PV and TZV showed a significant decrease at 3 months after TUNA (P < 0.01) as did the symptom score, quality of life (QOL) score and functional variables, and a decreased level of PV and TZV was sustained until 12 months of follow‐up when compared to the baseline (P < 0.01 at 6 months, not significant at 12 months). TZI also showed a similar pattern with a significantly decreased level until the postoperative 6th month (P < 0.05 at 6 months, not significant at 12 months). In ‘moderate’ cases, TZI achieved the minimum value (0.44 ± 0.13, P < 0.05 compared to the baseline) at 3 months of follow‐up, but the level immediately increased, while in ‘severe’ cases, TZI gradually decreased and achieved the minimum value (0.44 ± 0.08, P < 0.05 compared to the baseline) at 12 months of follow‐up. In the evaluation by postoperative therapeutic efficacy, there were no significant differences in PV, TZV and TZI between ‘excellent and good’ cases (E/G group) and ‘fair and poor/worse’ cases (F/P group) at the baseline or 3 months of follow‐up. Both of the efficacy groups showed a significant decrease in PV, TZV and TZI at 3 months when compared to the baseline (P < 0.05). The mean decrease in TZI was significantly larger in the E/G group than in the F/P group (0.064 ± 0.13 vs 0.027 ± 0.12, P < 0.05).

Conclusion: Therapeutic efficacy of TUNA did not depend on the baseline value of PV, TZV and TZI, but on variation of a decrease in TZI during follow‐up. Moreover, a slow and lasting decrease in TZI seemed to influence durability of the therapeutic efficacy of TUNA, which was clearly observed in ‘severe’ cases with a larger prostatic volume than in ‘moderate’ cases.
Progress towards achieving new vaccine and vaccination goals
Authors: Ada G.
Published: December 2004

Abstract

Viral and bacterial vaccines, especially for childhood use, are one of the most successful public health measures of the last two centuries and have a good safety record. However, there are still many diseases that are caused by infectious agents for which vaccines are not available. Our increasing ability to manipulate the immune system offers hope that, in the future, at least some of these infections may be prevented by vaccin­ation. A surprising recent development is the use of vaccine technology to test whether a range of other ­generally non‐communicable diseases can be prevented (or at least controlled) in this way. Investigation of these diseases is still mainly at the experimental level, however the list includes different types of cancers, allergies, drug addiction and neurodegenerative diseases. (Intern Med J 2003; 33: 297−304)
Stroke prevention: what's new?
Authors: Gerraty R. P.
Published: December 2004

Abstract

Antithrombotic treatment has now been joined by other evidence‐based drug interventions for pre­vention of stroke, including angiotensin‐converting enzyme inhibitors and hydroxymethylglutaryl‐CoA reductase inhibitors. The efficacy of oral anticoagulation in atrial fibrillation has not been seen in other stroke‐prone groups, although trials are continuing. Diffusion‐weighted magnetic resonance imaging improves diagnostic accuracy in acute stroke, which is important in arriving at the right secondary pre­vention strategy. Carotid endarterectomy has been shown to be beneficial for 50−69% symptomatic ­stenosis but with a much narrower therapeutic index than for 70−99% stenosis. A comparison of endarter­ectomy with angioplasty and/or stent placement has been the subject of one small trial suggesting similar procedural stroke and mortality risks. Device closure of cardiac abnormalities increases in the absence of any trial data, and in spite of a low subsequent stroke risk for young patients with isolated patent foramen ovale treated with aspirin. (Intern Med J 2003; 33: 177−181)
Helicobacter pylori infection in the Australian community: current prevalence and lack of association with ABO blood groups
Authors: Robertson M. S. , Cade J. F. , Savoia H. F. , Clancy R. L.
Published: December 2004

Aims: To assess the current prevalence of Helicobacter pylori infection in an Australian urban population sample and to relate this to age, gender and ABO and Rhesus blood groups.

Methods: We performed a prospective epidemio­logical survey of H. pylori serological status in 500 consecutive voluntary blood donors who presented for the purpose of blood donation at the central ­Melbourne branch of the Australian Red Cross Blood Service, Victoria, Australia, and gave a Melbourne suburban home address.

Results: The overall prevalence of specific anti‐H. pylori IgG antibodies in this cohort was 32% (95% confidence interval = 28−36%) and H. pylori sero­positivity increased with age. The rate of H. pylori infection was not significantly different in men and women, with anti‐H. pylori IgG anti­bodies detected in 35% (97/277) of men compared with 28% (63/233) of women (P = 0.12). Similarly, H. pylori serological status was not significantly different between subjects of different ABO (P = 0.18) or Rhesus blood groups (P = 0.55).

Conclusion:  This study showed that, contrary to expectation, the updated prevalence of H. pylori seropositivity (32%) in this Melbourne sample is at least as high as that found in previous Australian studies over the past 19 years. Seropositivity increased with age, and was not related to gender, confirming the infection pattern seen in other developed nations. Despite epidemiological evidence of increased peptic ulcer disease in ABO blood group O subjects, and recent evidence that H. pylori adhesion to gastric epithelial cells is mediated by blood group epitopes, no significant association between blood groups and H. pylori serological status was detected. (Intern Med J 2003; 33: 163−167)
Health and stress in Australian interns
Authors: Bruce C. , Thomas P. S. , Yates D. H.
Published: December 2004

Abstract

Over a 3‐year period, interns completed questionnaires on self‐reported health and stress during their orien­tation week at the beginning of the year, during mid year, and at the end of the first year. Interns experienced increased levels of stress and ill health in the middle of the year as compared with the start and end of the year (χ2 = 11.9, P = 0.003 and χ2 = 20.4, P < 0.001, respectively). Despite workplace reform for junior doctors, this study suggests that interns still feel overburdened with work expectations and this is having a negative effect on their health. (Intern Med J 2003; 33: 392−395)
An update on asthma management
Authors: Jenkins C.
Published: December 2004

Abstract

Asthma remains a major cause of morbidity in the Australian community, despite enhanced strategies and interventions for achieving optimal outcomes. Although there is some evidence of over use of high doses of inhaled corticosteroids (ICS), there is also evidence for under use of ICS, despite long‐term data demonstrating clear benefits of low doses. The present paper briefly discusses some of the issues that are pertinent to the development of sensitization and atopic disease, but focuses mainly on the current understanding of best clinical practice for adults with asthma and the optimal approach to management. A clear definition of asthma control and a systematic approach to down‐titration to minimize ICS doses is crucial to achieving better outcomes. Patient self‐management education and optimal therapy are the keys to achieving better outcomes, although uncertainty remains about recommendations for mild asthma, despite new data. (Intern Med J 2003; 33: 365−371)
Ethical aspects of blood and organ donation
Authors: Whyte G.
Published: December 2004

Abstract

Ethics of blood and organ donation in Australia has been influenced by voluntarism and the Red Cross. The General Agreement on Trade in Services may threaten the principle of voluntary blood donation and self suf­ficiency of blood in Australia. However, a cooperative approach to managing the public good is more sustain­able than individual self interest and the author argues that voluntary blood and organ donation should be retained. (Intern Med J 2003; 33: 362−364)
Patients’ autonomy in surgical care: a comparison of nurses’ perceptions in five European countries
Authors: Suhonen R. , Välimäki M. , Dassen T. , Gasull M. , Lemonidou C. , Scott P. A. , Kaljonen A. , Arndt M. , Leino‐Kilpi H.
Published: December 2004

Background: This report forms part of the results of an international comparative study funded by the European Commission (1998–2001). Aim: To describe and compare the maintenance of patients’ autonomy on surgical wards, from the point of view of nursing staff, in five European countries (Finland, Spain, Greece, Germany and Scotland). Autonomy is defined in terms of information received and decision making by patients. Method: The data were collected using a questionnaire specifically designed for use in this study. Responses (response rate 66%) were obtained from 1280 nurses working on surgical wards. Data analysis was based on descriptive statistics, t‐tests, analysis of variance (ANOVA) with posthoc Tukey's HSD test and logistic regression. Results: There were clear between‐country differences in nurses’ perceptions, especially on a north–south axis (Finland and Scotland vs. Greece and Spain), regarding the extent to which the autonomy of surgical patients is supported by nursing staff. Training and ethics education, in particular, were associated with nurses’ perceptions of the maintenance of patient autonomy in Finland and Greece. Conclusion: Further research is needed to establish whether the results obtained are caused by differences in cultures, nursing practices or roles of health‐care personnel or patients in different European countries.
Why an ICNP? Links among quality, information and policy
Authors: Baernholdt M. , Lang N. M.
Published: December 2004

Work has been underway for over a decade to develop and use the International Classification for Nursing Practice (ICNP). The International Council of Nurses has released ICNP Alpha and Beta versions. This article is an adaptation of the presentation given at the International Council of Nurses Congress on June 12th, 2001, in Copenhagen, Denmark. When the ICNP was originally drafted, many uses were envisioned. Key among these were that the information generated would be used by clinicians, researchers, administrators and policy makers. This article introduces examples of these uses.
What do women think about menopause? A qualitative study of women's expectations, apprehensions and knowledge about the climacteric period
Authors: Berterö C.
Published: December 2004

Aim: To identify and describe expectations, apprehensions and knowledge about the menopausal period and climacteric symptoms. Method: Data were collected by semi‐structured interviews/discussions with a convenience sample of 39 women, all 47 years of age. Data interpretation and analysis were based on content analysis, but influenced by a qualitative approach. Findings: These included women's expectations and feelings of freedom. Apprehensions were described as different climacteric symptoms, which were well known to the women through their own or other's experiences. The women were, to some extent, aware of the physical and psychological changes that follow the menopause. However, the women lacked knowledge about these changes or self‐care activities that could prevent problems or mitigate symptoms. Key conclusions and implications for practice: Discussions on health with premenopausal women can increase their knowledge about a natural phase of life, the climacteric period. The study showed that nurses/midwives who have regular contact with some women during their life have an important role to play in providing information, as well as in the treatment of climacteric symptoms.
Decision‐making preferences towards surgical intervention in a Hong Kong Chinese population
Authors: Henderson A. , Shum D.
Published: December 2004

Background: Economic, social, ethical and legal concerns are motivating changes in western‐type health practice to encourage individuals to participate in health‐care decisions. Patient participation in health care is perceived to be beneficial because health care is negotiated with the patient so the selected regimen of care is more likely to be acceptable. Hong Kong, in accordance with contemporary trends in other industrialized countries, has adopted a Patient's Charter that outlines patient's rights regarding health treatment and choices. Studies indicate that not all patients wish to take part in decision making about treatment. Aim: To explore the degree to which a Hong Kong Chinese population desired to participate in decision making about surgical intervention. Method: 96 participants, 49 surgical and medical patients and 47 students of nursing, participated. Participants were given three hypothetical scenarios: cardiac failure, where major surgery is suggested; cholecystitis, where routine surgery is suggested; and the presence of a benign skin lesion, where minor surgery is suggested. Participants were asked about the degree to which they desired to participate in the decision‐making process. There were five choices, ranging from the doctor having full control, to various types of collaborative decision making, to the individual having full control. Results: When the medical condition is not severe, participants desired greater participation in the decision‐making process. Younger participants desired greater collaboration with the doctor in decision making while older participants preferred the doctor to have the greater input with respect to decision making.
Comparison of Electrocardiogram and Intrathoracic Electrogram Signals for Detection of Ischemic ST Segment Changes During Normal Sinus and Ventricular Paced Rhythms
Authors: THERES HEINZ , STADLER ROBERT W. , STYLOS LEE , GLOS MARTIN , LEUTHOLD THOMAS , BAUMANN GERT , NELSON SHANNON D. , KRUCOFF MITCHEL W.
Published: December 2004

ST Segment Changes in ECG and EGM Signals.
Introduction: The aim of this study was to compare surface ECGs with electrograms (EGM) that are available from implanted devices for the ability to detect ischemic ST segment changes during normal sinus (NS) and ventricular paced (VP) rhythms.

Methods and Results: ECG leads I, II, and V2, right atrial ring to left pectoral patch (representing the can of the device), right ventricular ring to left pectoral patch, and right atrial ring to right ventricular ring EGM were recorded continuously during percutaneous transluminal coronary angioplasty. One balloon inflation (≥60 sec) was analyzed from each of 22 NS and 22 VP subjects. The parameter ΔST was defined as the maximum absolute ST segment deviation (from isoelectric) during the first 60 seconds of inflation, measured relative to the baseline (preinflation) ST segment deviation. For EGM, a normalized ΔST was defined as the ΔST divided by the ratio of QRS amplitudes of EGM to ECG. During NS, the ΔST for EGM (0.43 mV) was significantly larger than that of ECG (0.09 mV, P = 0.0001) but the normalized ΔST for EGM (0.11 mV) was comparable to that of ECG (0.09 mV, P = 0.45). During VP, the ΔST for EGM (1.08 mV) was significantly larger than that of ECG (0.17 mV, P = 0.0001), but the normalized ΔST for EGM (0.11 mV) was significantly smaller than that of ECG (0.17 mV, P = 0.02).

Conclusion: During both NS and VP, ischemic ST segment changes were significantly larger in EGM than in ECG. Much of this difference appears to be related to larger amplitudes of EGM signals.
Circadian and Seasonal Variation of Malignant Arrhythmias in a Pediatric and Congenital Heart Disease Population
Authors: STEPHENSON ELIZABETH A. , COLLINS KATHRYN K. , DUBIN ANNE M. , EPSTEIN MICHAEL R. , HAMILTON ROBERT M. , KERTESZ NAOMI J. , ALEXANDER MARK E. , CECCHIN FRANK , TRIEDMAN JOHN K. , WALSH EDWARD P. , BERUL CHARLES I.
Published: December 2004

Circadian Rhythms in Pediatric De. brillator Discharges.
Introduction: Recent studies in adult populations have revealed seasonal variation in the frequency of acute cardiovascular events, including life‐threatening arrhythmias, demonstrating increased events during winter and early spring. Trends in the time of day that arrhythmias occur also were noted. We sought to establish whether pediatric and young adult congenital heart disease implantable cardioverter defibrillator (ICD) recipients have circadian or seasonal variability in shock frequency, similar to adult populations.

Methods and Results: Data from ICD patients at six pediatric centers in North America were analyzed to assess the timing of life‐threatening arrhythmias. The populations consisted of children and adults with congenital heart disease and ICDs placed for malignant arrhythmias. Data were considered in 46 patients who received appropriate therapy (total 139 episodes) for ventricular tachycardia or ventricular fibrillation. Multiple variables were analyzed, including time of day, day of week, and month of year. In contrast to previously studied adult patients, fewer events occurred in the early morning (7.5%), with the most therapies occurring between 6 P.M. and midnight (35%). An increased frequency of therapies was observed in the fall and winter (September‐January), representing 60% of all appropriate shocks. Unlike adult populations, Mondays did not have an increased frequency of malignant arrhythmias.

Conclusion: Pediatric and adult congenital heart disease populations have moderate seasonal and 24‐hour variation in ICD event rate, with some distinctly different peaks than those seen in typical adult ICD populations. These findings suggest circadian variation in arrhythmia vulnerability that may differ from conventional occupational, physical, or emotional stressors.
Estimated Global Epicardial Distribution of Activation Rate and Conduction Block During Porcine Ventricular Fibrillation
Authors: NEWTON JONATHAN C. , JOHNSON PHILLIP L. , JUSTICE R. KYLE , SMITH WILLIAM M. , IDEKER RAYMOND E.
Published: December 2004

Block and Frequency Distribution During VF.
Introduction: A proposed mechanism of the maintenance of ventricular fibrillation (VF) determined by studying small hearts or segments of large hearts is that a single stable rotor exists at the site of maximal activation rate, which gives rise to activation fronts that propagate into slower activating regions where they frequently block. We wished to determine if two predictions of this hypothesized mechanism are true during VF in large hearts: (1) there is a single maximum in the distribution of activation rates with the activation rate decreasing with distance away from this maximum; and (2) the incidence of block is greater outside than inside the fastest activating region.

Methods and Results: Six 25‐second episodes of VF from each of six pigs were recorded from 504 electrodes over the entire ventricular epicardium. The electrodes were divided into four zones: left ventricular base and apex (LVB and LVA) and right ventricular base and apex (RVB and RVA). A fast Fourier transform was performed on each electrogram, and the mean activation rate was estimated from the dominant (peak) frequency (DF) and block was estimated to be present during those time intervals when double peaks (DPs) were present in the power spectrum. The zones had statistically significant distributions of DF (LVB> LVA> RVA> RVB) and DP incidence (RVA> RVB> LVA> LVB).

Conclusion: During VF, the LV base has the highest estimated activation rate and the lowest estimated block incidence, and the RV has the slowest rate but the highest block incidence. This is consistent with the concept of VF being maintained by activation fronts originating from the LV base.
Left Ventricular Outflow Tract Tachycardia Originating from the Right Coronary Cusp: Identification of Location of Origin by Endocardial Noncontact Activation Mapping from the Right Ventricular Outflow Tract
Authors: STOREY JAMES , IWASA ATSUSHI , FELD GREGORY K.
Published: December 2004

Left Ventricular Outflow Tract Tachycardia. Idiopathic left ventricular outflow tract (LVOT) tachycardia has been shown to originate from a supravalvular site in some patients. Considerable attention recently has focused on identifying this variant of LVOT tachycardia on 12‐lead ECG. We report the case of 15‐year‐old boy in whom a noncontact three‐dimensional mapping electrode deployed in the right ventricular outflow tract (RVOT) assisted in identifying a supravalvular LVOT tachycardia. Observation of two early breakthrough sites in the RVOT and right ventricular septum suggested a right aortic cusp origin of the tachycardia. Pace mapping in the right aortic cusp identified a successful ablation site.
Efficacy and Safety of Targeted Focal Ablation Versus PV Isolation Assisted by Magnetic Electroanatomic Mapping
Authors: MARCHLINSKI FRANCIS E. , CALLANS DAVID , DIXIT SANJAY , GERSTENFELD EDWARD P. , RHO ROBERT , REN JIAN‐FANG , ZADO ERICA
Published: December 2004

Introduction: Pulmonary vein (PV) triggers initiate atrial fibrillation (AF). The aim of this study was to compare the outcome of focal PV ablation versus targeted PV electrical isolation aided by multipolar catheter recordings in the coronary sinus (CS) and right atrium and magnetic electroanatomic mapping (MEAM) for drug‐refractory AF.

Methods and Results: Multipolar recordings identified PVs with triggers based on PV ostial pace map match for spontaneous and provoked triggers. PV triggers were provoked by isoproterenol, adenosine, and AF induction followed by cardioversion. MEAM defined PV ostial anatomy and assisted in localization of AF trigger and ablation lesions. All focal PV ablation procedures preceded PV isolation procedures at our institution. To limit a learning curve effect and validate the comparison, the results included outcome of procedures by a single experienced operator in the last 32 consecutive patients undergoing focal PV ablation and in 75 consecutive patients undergoing PV isolation. Patient characteristics were similar with respect to mean age (50 vs 52 years), mean left atrial size (4.3 vs 4.2 cm), presence of paroxysmal AF (84% vs 88%), and demonstration of non‐PV triggers (16% in both groups). PV isolation was confirmed in 99% of PVs by multipolar circular catheter. MEAM confirmed noncircumferential ostial ablation in 69% of PVs. Patients undergoing PV isolation had less AF from PV triggers at the end of ablation (1% vs 16%,

P < 0.01

); had less AF at 2 months (17% vs 42%,

P < 0.001

); and had 1‐year freedom from AF of 80% versus 45%

(P < 0.001)

. Adverse events were low in both groups with no stroke or symptomatic PV stenosis.

Conclusion: Using the described techniques, PV electrical isolation of PVs demonstrating spontaneous and/or provoked triggers is superior to focal PV ablation, with marked differences in outcome by 2 months. MEAM confirmed the noncircumferential nature of ostial ablation for effective isolation of most PVs and may play a role in the low risk and good outcome observed. The good outcome of targeted PV isolation as described suggests the need for a prospective comparison of targeted versus empiric PV isolation techniques.
(J Cardiovasc Electrophysiol, Vol. 14, pp. 358‐365, April 2003)
Useful Tip to Improve Electrode Positioning in Markedly Angulated Coronary Sinus Tributaries
Authors: DEBRUYNE PHILIPPE , GEELEN PETER , JANSSENS LUC , BRUGADA PEDRO
Published: December 2004

The anatomic variability of the cardiac veins limits the feasibility of cardiac resynchronization therapy. This report describes another way to position the pacemaker electrode in sharply angulated coronary sinus branches.
(J Cardiovasc Electrophysiol, Vol. 14, pp. 415‐416, April 2003)
Pericardial Anatomy for the Interventional Electrophysiologist
Authors: D'AVILA ANDRE , SCANAVACCA MAURICIO , SOSA EDUARDO , RUSKIN JEREMY N. , REDDY VIVEK Y.
Published: December 2004

Investigators are beginning to exploit the pericardial space for a number of cardiovascular applications, including catheter ablation of cardiac arrhythmias, cardiovascular drug therapy, and cardiac pacing. This review explores the anatomy of the pericardial space and the anatomic variants that may be encountered in this novel approach to the heart.
(J Cardiovasc Electrophysiol, Vol. 14, pp. 422‐430, April 2003)
Implantable Cardioverter Defibrillator Lead Complications and Laser Extraction in Children and Young Adults with Congenital Heart Disease: Implications for Implantation and Management
Authors: COOPER JOSHUA M. , STEPHENSON ELIZABETH A. , BERUL CHARLES I. , WALSH EDWARD P. , EPSTEIN LAURENCE M.
Published: December 2004

Introduction: Implantable cardioverter defibrillators (ICDs) are being implanted for primary and secondary prevention of sudden death in children and young adults with congenital heart disease. Over time, ICD leads adhere to venous endothelium and endocardium. Lead removal, when necessary, often requires disruption of this fibrous tissue.

Methods and Results: We retrospectively reviewed and analyzed our experience with ICD lead extraction in children and young adults with congenital heart disease. From April 1999 through January 2002, 14 patients underwent 15 lead extraction procedures to remove 21 leads (17 ICD leads and 4 pacing or sensing leads). Seven patients had surgically corrected structural heart disease (5 transposition of the great arteries with atrial switch repair and 2 corrected tetralogy of Fallot). Mean patient age at extraction was

17.9 ± 5.7 years

(range 9–32), and mean duration of lead implantation was

42.0 ± 18.9 months

(range 15–75). Fourteen of 15 procedures were performed for lead fracture or failure. A laser sheath was used for 20 of 21 lead extractions. Twenty of 21 leads (95%) were completely extracted. There were three instances of blood loss requiring transfusion. There were no major complications or deaths.

Conclusion: Young congenital heart disease patients with an ICD are at risk for growth‐related lead distortion. The use of a laser sheath is safe and effective for ICD lead extraction in congenital heart disease patients, despite coil adherence and altered anatomy. It may be advisable to avoid dual‐coil leads in patients with the potential for future growth.
(J Cardiovasc Electrophysiol, Vol. 14, pp. 344‐349, April 2003)
Prospective Randomized Study of Mode Switching in a Clinical Trial of Pacemaker Therapy for Sinus Node Dysfunction
Authors: SWEENEY MICHAEL O. , HELLKAMP ANNE S. , ELLENBOGEN KENNETH A. , GLOTZER TAYA V. , SILVERMAN RUSSELL , YEE RAYMOND , LEE KERRY L. , LAMAS GERVASIO A. ,   for the MOST Investigators
Published: December 2004

Introduction:Atrial fibrillation (AF) is common in pacemaker patients with sinus node dysfunction (SND) and may result in rapid ventricular pacing (RVP) in the DDDR mode. Mode switching (MS) reduces RVP, but its clinical benefit in patients with SND is unknown.

Methods and Results:Two hundred two patients in the Mode Selection Trial (MOST; 2,010‐patient, 6‐year trial of DDDR vs VVIR pacing in SND) randomized to DDDR pacemakers with atrial high‐rate episode (AHRE) storage capabilities were subrandomized to MS ON (N = 96) or MS OFF (N = 106). Cardiovascular symptoms, quality of life (QOL), reprogramming due to RVP, death, stroke, and heart failure hospitalization (HFH) were compared between groups. The treatment groups were similar with regard to AF history (59% MS ON vs 57% MS OFF). AHREs occurred in 49% patients during median follow‐up of 2.2 years. Median AHRE duration (in min; MS ON 116 vs MS OFF 58, P = 0.29), frequency AHREs/week (MS ON 3.5 vs MS OFF 6.4, P = 0.23), and time spent in AHRE (min/week) (MS ON 450, MS OFF 268) were similar. Reprogramming due to any RVP during AHREs occurred more in MS OFF vs MS ON (13.2% vs 3.1%, P = 0.011) and marginally more for symptomatic RVP (8.5% vs 2.1%, P = 0.062). Cardiovascular symptoms occurred in 93.6% MS ON vs 90.2% MS OFF (P = 0.38). Median number of symptoms reported per visit was similar (MS ON 1.3 vs MS OFF 1.5, P = 0.62). Median symptom frequency/severity, summed and averaged over visits, was similar (MS ON 4.3 vs MS OFF 4.5, P = 0.74). QOL was not different between groups. Death, stroke, and HFH were not different between groups.

Conclusion:MS reduces pacemaker reprogramming due to RVP during AHREs in a small number of patients but does not improve QOL or cardiovascular symptoms overall among patients with SND.(J Cardiovasc Electrophysiol, Vol. 15, pp. 153‐160, February 2004)
Ablation of Focally Induced Atrial Fibrillation:
Authors: DILLING‐BOER DAGMARA , MERWE NICO VAN DER , ADAMS JOZEF , FOULON STEFAAN , GOETHALS HUBERT , WILLEMS RIK , ECTOR HUGO , HEIDBÜCHEL HEIN
Published: December 2004

Introduction: Focally induced atrial fibrillation (AF) often is due to ectopic activity in the pulmonary veins (PV). Although initial approaches were aimed at ablating only the ectopic foci, more extensive ablation approaches have evolved that isolate all PVs empirically and/or create circumferential ablation lines in the left atrium (LA). These techniques last longer and may be associated with more risks. We retrospectively evaluated the outcome and risks of ablation for focally induced AF in a single‐center patient population.

Methods and Results: We report on 47 patients (32 men and 15 women; age 47 ± 10 years) in whom 52 ablations were performed. In 19 patients (22 sessions), ablation was directed at the site(s) of overt ectopic activity (“selective” group), whereas in 28 patients (30 sessions) without sufficient ectopy to determine the culprit PV a mean of 3.5 PVs were empirically targeted for bidirectional disconnection from the LA (“extensive” group). On a preprocedural Holter recording, the “selective” group had significantly more isolated atrial ectopy (3,276 ± 2,933 vs 620 ± 937 beats/24 hours) and runs of atrial tachycardia (330 ± 202 vs 53 ± 87 runs/24 hours) than the “extensive” group (P < 0.01 for both). Only 11% had persistent AF before ablation. Acute procedural success was 81% (elimination of all ectopy) and 83%, respectively (bidirectional and fully circumferential isolation of all targeted PVs). Procedure and fluoroscopy times were significantly shorter in the “selective” group. There were no major complications, but 7 minor complications and 2 acute PV stenoses > 50% in the 30 “extensive” procedures were observed. Mean follow‐up was 8.4 ± 8.5 months (median 6.9). Kaplan‐Meier analysis, excluding recurrences during only the first month (“delayed cure”), showed AF recurrence in 45% after 6 months and in 55% after 1 year. Outcome was not dependent on ablation approach (“selective” or “extensive”) nor was time to first AF (22 ± 64 days and 30 ± 69 days). AF recurrence tended to be higher in patients with larger LA (P = 0.08), underlying heart disease or hypertension (P = 0.08), and those “extensive” patients in whom not all 4 PVs were targeted (P = 0.07).

Conclusion: Trigger‐directed ablation for focally induced AF is associated with a relatively high recurrence rate during follow‐up. Apart from recurrence of the ectopic trigger, this may point to underlying structural changes in the atrial substrate not addressed by the ablation. Prospective evaluation of the risk‐to‐benefit profile of any technique (selective, extensive, including linear lines) is required. (J Cardiovasc Electrophysiol, Vol. 15, pp. 200‐205, February 2004)
Enhanced Detection of Arrhythmia Vulnerability Using T Wave Alternans, Left Ventricular Ejection Fraction, and Programmed Ventricular Stimulation:
Authors: RASHBA ERIC J. , OSMAN AHMED F. , MACMURDY KAREN , KIRK MALCOLM M. , SARANG SAMANTHA E. , PETERS ROBERT W. , SHOROFSKY STEPHEN R. , GOLD MICHAEL R.
Published: December 2004

Introduction: In previous studies, the prognostic value of T wave alternans (TWA) was similar to that of programmed ventricular stimulation (PVS). However, presently it is unclear if TWA and PVS identify the same patients or provide complementary risk stratification information. In addition, the effects of left ventricular ejection fraction (LVEF) on the prognostic value of TWA are unknown. The aim of this study was to determine if combined assessment of TWA, LVEF, and PVS improves arrhythmia risk stratification.

Methods and Results: This was a prospective study of 144 patients with coronary artery disease and LVEF ≤40% who were referred for PVS for standard clinical indications. The endpoint was the combined incidence of death, sustained ventricular arrhythmias, and appropriate implantable cardioverter defibrillator (ICD) therapy. TWA (hazard ratio 2.2, P = 0.03) and PVS (hazard ratio 1.9, P = 0.05) both were significant predictors of endpoint events, and TWA was the only independent predictor. LVEF markedly influenced the prognostic value of TWA, which was a potent predictor of events in subjects with LVEF between 30% and 40% (event rates: TWA+ 36%, TWA‐ 0%, P = 0.001) but did not predict events in subjects with LVEF <30% (hazard ratio 1.1, P > 0.5). PVS successfully identified additional low‐risk patients within the cohort with negative or indeterminate TWA results (hazard ratio 4.7, P = 0.015) but did not provide incremental prognostic information for TWA+ patients (hazard ratio 0.9, P > 0.5).

Conclusion: The combined use of TWA, LVEF, and PVS is a promising new approach to arrhythmia risk stratification that permits identification of high‐risk and very‐low‐risk patients. (J Cardiovasc Electrophysiol, Vol. 15, pp. 170‐176, February 2004)
Left Ventricular Endocardial Lead Placement Using a Modified Transseptal Approach
Authors: JI SEN , CESARIO DAVID A. , SWERDLOW CHARLES D. , SHIVKUMAR KALYANAM
Published: December 2004

Coronary sinus cannulation and placement of left ventricular (LV) leads can be difficult. Occasionally alternative approaches are required. We report the first case of a modified transseptal LV endocardial lead placement via the left axillary vein for cardiac resynchronization. (J Cardiovasc Electrophysiol, Vol. 15, pp. 234‐236, February 2004)
Cardiac Surgery for Arrhythmias
Authors: L. COX JAMES
Published: December 2004

Cardiac arrhythmia surgery was initiated in 1968 with the first successful division of an accessory AV connection for the Wolff‐Parkinson‐White syndrome. Subsequent surgical procedures included the left atrial isolation procedure and right atrial isolation procedure for automatic atrial tachycardias, discrete cryosurgery of the AV node for AV nodal reentrant tachycardia, the atrial transection procedure, the corridor procedure, and the maze procedure for atrial fibrillation, the right ventricular disconnection procedure for arrhythmogenic right ventricular tachycardia, and the encircling endocardial ventriculotomy, subendocardial resection procedure, endocardial cryoablation, the Jatene procedure, and the Dor procedure for ischemic ventricular tachycardia. Because of monumental strides in the treatment of most refractory arrhythmias by endocardial catheter techniques during the past decade, the only remaining viable surgical procedures for cardiac arrhythmias are the maze procedure for atrial fibrillation and the Dor procedure for ischemic ventricular tachycardia. Nevertheless, the 25 to 30 years of intense activity in the field of cardiac arrhythmia surgery provided the essential foundation for the development of these catheter techniques and represent one of the most exciting and productive eras in the history of medicine. In one short professional career, we have witnessed the birth of arrhythmia surgery, its adolescence as an “esoteric” specialty, its prime as an enlightening yet exhausting period, and finally its waning years as a source of knowledge and wisdom upon which better methods of treatment have been founded. One could hardly ask for a more rewarding experience. (J Cardiovasc Electrophysiol, Vol. 15, pp. 250‐262, February 2004)