Measuring the Complexity of Atrial Fibrillation Electrograms

AF Electrogram Complexity. Introduction: Complex fractionated atrial electrograms (CFAE) have been identified as targets for atrial fibrillation (AF) ablation. Robust automatic algorithms to objectively classify these signals would be useful. The aim of this study was to evaluate Shannon's entropy (ShEn) and the Kolmogorov‐Smirnov (K‐S) test as a measure of signal complexity and to compare these measures with fractional intervals (FI) in distinguishing CFAE from non‐CFAE signals. Methods and Results: Electrogram recordings of 5 seconds obtained from multiple atrial sites in 13 patients (11 M, 58 ± 10 years old) undergoing AF ablation were visually examined by 4 independent reviewers. Electrograms were classified as CFAE if they met Nademanee criteria. Agreement of 3 or more reviewers was considered consensus and the resulting classification was used as the gold standard. A total of 297 recordings were examined. Of these, 107 were consensus CFAE, 111 were non‐CFAE, and 79 were equivocal or noninterpretable. FIs less than 120 ms identified CFAEs with sensitivity of 87% and specificity of 79%. ShEn, with optimal parameters using receiver‐operator characteristic curves, resulted in a sensitivity of 87% and specificity of 81% in identifying CFAE. The K‐S test resulted in an optimal sensitivity of 100% and specificity of 95% in classifying uninterpretable electrogram from all other electrograms. Conclusions: ShEn showed comparable results to FI in distinguishing CFAE from non‐CFAE without requiring user input for threshold levels. Thus, measuring electrogram complexity using ShEn may have utility in objectively and automatically identifying CFAE sites for AF ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 649‐655, June 2010)     

Adults with cerebral palsy: a workshop to define the challenges of treating and preventing secondary musculoskeletal and neuromuscular complications in this rapidly growing population

Although the neurological injury associated with cerebral palsy (CP) is non-progressive, adults with the disorder often develop musculoskeletal and neurological symptoms, such as severe pain, chronic fatigue, and a premature decline in mobility and function, as they age. Little is known about how to manage, much less prevent, these symptoms. This paper summarizes the findings of a multi-disciplinary workshop, sponsored by the Cerebral Palsy International Research Foundation, the American Academy for Cerebral Palsy and Developmental Medicine, and Reaching for the Stars, convened to review current knowledge and begin to develop a blueprint for future research. The goals of the workshop were to (1) define the current incidence and prevalence of CP, (2) review the known complications for persons aging with CP, (3) review current understanding of physiological processes that may contribute to loss of function and premature aging in CP, (4) evaluate current treatment interventions in terms of long-term outcomes, (5) identify cutting-edge technologies in neurorehabilitation that may help prevent or treat the effects of accelerated aging for persons diagnosed with CP, and (6) identify strategies to ensure that individuals with CP receive evidence-based care as they transition from pediatric to adult-care services.     

Diabetes and Multiple Stents Independently Double the Risk of Short-term Revascularization

Several studies show worse outcome for diabetic patients after percutaneous transluminal coronary angioplasty (PTCA). There are relatively few studies evaluating outcome in the modern era of coronary stenting. We compared the incidence of death, myocardial infarction (MI), and repeat target lesion revascularization (RTLR) by PTCA or coronary artery bypass grafting (CABG) over a 6-month follow-up in 110 diabetic and 400 nondiabetic patients receiving Palmaz-Schatz stents. All patients received aspirin/ticlopidine and stents were deployed using high-pressure inflations. Seventy-five (68.2%) diabetic patients and 272 (68%) nondiabetic patients had single stents, while 35 (31.8%) diabetic and 128 (32%) nondiabetic patients had multiple stents (≥ 2stents in the same vessel). The success rate and acute major complications were not significantly different between diabetic and nondiabetic patients. There was also no significant difference in death, MI, and repeat PTCA between these two groups. Diabetic patients underwent CABG more frequently than nondiabetic patients (12.7% vs 3.2%, respectively, P =0.001) and diabetic patients also had RTLR more frequently than nondiabetic patients (25.5% vs 12.8%, respectively, P = 0.002) during 6-month follow-up. Multivariate analysis showed that diabetes and multiple stents independently contributed to the 6-month RTLR rate. Coronary stenting in diabetic patients can be carried out with a high success rate and low incidence of acute major complications. The presence of diabetes mellitus and multiple stent placement significantly increase the incidence of repeat target lesion revascularization.     

ERA SPECIFIC BIOCHEMICAL RECURRENCE-FREE SURVIVAL FOLLOWING RADICAL PROSTATECTOMY FOR CLINICALLY LOCALIZED PROSTATE CANCER

PURPOSE: We retrospectively reviewed a large series of men with clinically localized prostate cancer who underwent surgery to define the extent of stage migration and its influence on biochemical recurrence in 3 different eras of prostate cancer management. MATERIALS AND METHODS: A total of 2,370 men were treated with radical prostatectomy from 1982 to 1998. We analyzed the freedom from biochemical (prostate specific antigen) progression after radical prostatectomy. We compared the distribution of pathological stage by the year of surgery. We then compared the biochemical recurrence-free survival rate according to the different eras that reflect a change in prostate cancer management. RESULTS: There was a significant downward stage migration of prostate cancer and an increasing proportion of men who presented with organ confined disease in recent years. The actuarial biochemical recurrence-free rate was significantly different for patients who underwent surgery between 1982 and 1988, compared with those between 1989 and 1998 (p <0.001). These changes may have reflected the benefits of early detection with prostate specific antigen and digital rectal examination, better preoperative selection of patients for surgery as well as the effect of lead time. CONCLUSIONS: Widespread early detection programs for prostate cancer resulted in downward stage migration in men presenting with prostate cancer at our institution during the last 18 years. Also, we have demonstrated a biochemical recurrence-free survival advantage, probably secondary to an improved therapeutic outcome as well as lead time bias, in men who underwent surgery between 1989 and 1998, compared with those between 1982 and 1988. When trying to compare the efficacy of different treatment modalities for prostate cancer, the era in which patients underwent therapy is an important factor to be considered.     

Susceptibility of N'Dama and Boran cattle to sequential challenges with tsetse-transmitted clones of Trypanosoma congolense

Summary The susceptibility of N'Dama cattle ( Bos taurus ) to four consecutive infections with different tsetse-transmitted clones of Trypanosoma congolense was compared with that of Borans ( Bos indicus ). All animals were aged 13 months al the start of the study and had been born and raised free from trypanosomiasis under the same management and nutritional conditions, thereby limiting environmental factors that could have influenced susceptibility. While cattle of both breeds were equally susceptible to the establishment of trypanosome infections, the N'Damas exhibited superior resistance. Despite infection with virulent parasites, the N'Damas gained weight at the same rate as uninfected control animals, they did not develop anaemia to the extent that trypanocidal drug treatment was required, and all made a spontaneous recovery to normal hacmatological values within two to four months. In contrast, all the Borans needed treatment during the course of the four infections because of severe anaemia and showed markedly reduced liveweight gains. These clinical differences in the N'Damas were associated with two repcatable characteristics, namely, the ability to control parasitaemia and to'resist' anaemia, processes that did not appear to be linked. Also in contrast to the Borans. the N'Damas were able to mount accelerated haemopoietic responses, resulting in the reduced severity of anaemia following a primary infection. These findings pose the question as to whether the ability to control parasitaemia and to'resist' anaemia could be used as criteria for identifying resistant or trypanotolerant cattle.     

DOUBLE-BLIND RANDOMIZED MULTICENTRE TRIAL OF ACAMPROSATE IN MAINTAINING ABSTINENCE FROM ALCOHOL

A prospective placebo-controlled, randomized double-blind studyof Acamprosate at two dose levels in alcohol-dependent patientsfollowed up for 12 months was performed. After detoxification,each of the 538 patients included was randomly assigned to oneof three groups: 177 patients received placebo, 188 receivedAcamprosate at 1.3 g/day (low dose group) and 173 received 2.0g/day(high dose group) for 12 months. This was followed by a singleblind 6 month period on placebo. The patients' mean age was43.2 ± 8.6 years. Their mean daily alcohol intake washigh (nearly 200g/day) and of long duration (9.5 ± 7.1years). Abstinence figures followed the order high dose>lowdose>placebo. The difference was significant at 6 months(P