EP radiofrequency generators: Significant offsets between selected and delivered power?

INTRODUCTION: For radiofrequency (RF) ablation, the EP Shuttle® (Stockert GmbH, Freiburg, Germany), Ampere® (St. Jude Medical, St. Paul, MN, USA), and SmartAblate® (Biosense Webster, Diamond Bar, CA, USA) generator models are most frequently used in clinical practice. The aim of this study was to assess the correlation between selected and delivered RF power for different generators. METHODS AND RESULTS: In an experimental setup, ablation catheters were connected to the EP Shuttle® , Ampere® , and SmartAblate® generators. The power delivered by the generators was measured using a current converter and an oscilloscope. The selected power displayed on the generator was compared to the actually delivered power measured by the experimental setup (n = 800 measurements). The offsets between selected and delivered power increased significantly with impedance (EP Shuttle® ). For example, at a selected power of 30 W, the delivered power was 40.3 W (EP Shuttle® ), 30.1 W (Ampere® ), and 28.1 W (SmartAblate® ) at an impedance of 200 Ω. In addition, ablation lesions (n = 80) were created in ex vivo porcine cardiac muscle preparations. The resulting ablation lesion size was calculated in caliper measurements. When the EP Shuttle® generator was operated at 200 Ω, the resulting lesion size was significantly larger than at 100 Ω. There were no significant offsets between power delivery and lesion size when using the Ampere® or SmartAblate® generators. CONCLUSIONS: The Ampere® and SmartAblate® generator models deliver accurate power as selected by the user. The power delivered by the EP Shuttle® generator exceeds the selected power by up to 40% depending on impedance. The findings were confirmed in ex vivo porcine heart experiments and should be considered in clinical practice.

Treatment costs of bladder pain syndrome/interstitial cystitis in Austria: a pharmacoeconomic approach following current guidelines.

BACKGROUND: Bladder pain syndrome/interstitial cystitis (BPS/IC) is a chronic disease with a significant impact on quality of life. A broad range of therapies are used to treat this condition, and patients are often excluded from receiving more expensive and more effective therapies because of cost issues. OBJECTIVE: The objective of this study was to assess the mid- and long-term costs (over 1, 5 and 10 years) of various therapies for BPS/IC. METHODS: Costs in an open-access health system (Austria) for three BPS/IC-specific therapies (intravesical hyaluronan, pentosanpolysulfate and amitriptyline), taken from the American Urological Association guidelines, were evaluated and compared with those of non-specific symptomatic therapies. Response rates for the different therapies were taken from peer-reviewed publications and used to define the need for therapy maintenance with regard to symptom improvement. RESULTS: Despite the highest initial costs, the reduced need for further therapy in patients with long-term symptom remission after hyaluronan therapy resulted in the lowest total treatment costs at all three timepoints. Hyaluronan was cost saving against all alternatives in standard assumptions and in all sensitivity analyses. As a limitation, treatment costs in this study are specific for Austria. However, the template used for calculation of treatment costs can be transferred to all countries by inserting local prices. CONCLUSION: Disease-specific therapies with high remission rates result in significantly lower long-term costs in BPS/IC. Non-specific symptomatic therapies are most expensive. Long-term cost effectiveness is crucial in the treatment of chronic diseases to limit expenses in individual healthcare systems.

Background morbidity of headache in an adult general population. Results of the Austrian SERMO (Self-Reported Morbidity) study.

STUDY OBJECTIVE: To assess period and point prevalence of headache in Austria and the influence of sociodemographic factors and seasonal variations. DESIGN: Data for the prevalence of headache were drawn from the database of seven representative surveys in the SERMO study (Self-Reported Morbidity Study). The aims of the SERMO study are to describe and monitor the characteristics of background morbidity in the Austrian population. The study is based on face-to-face interviews. Headache/migraine was one of 36 disorders the interviewed persons were asked about. SETTING: The representative samples of the Austrian general population were selected by the "quota-procedure". Thus each cross sectional sample is representative for the entire Austrian population. PARTICIPANTS: The study population consisted of 7,162 Austrian people over 15 years of age. RESULTS: About one fifth (20.1%) of the Austrian adult population reported having headaches during the year (prevalence 26.4% in women vs. 13.0% in men, p<0.001). Period prevalences varied from 19.6% in August to 23.1% in October 1995. Mean point prevalence in the general population was 5.7% (3.6% in men vs. 7.7% in women, p<0.001). The highest point prevalence (8.0%) was observed among people over 60. Whereas period prevalence showed no trend with age or education, we found increasing point prevalence with age and lower levels of education. In general, significantly more people with self-reported headache suffered from stress (39.1% vs. 33.7%, p<0.001) and chronic diseases (33.6% vs. 23.2%, p<0.001) and took drugs regularly (all kinds of medication: 44.3% vs. 26.8%, p<0.001). CONCLUSIONS: Headache is one of the most commonly experienced symptoms in Austria. The most common concomitant disease in the study population as a whole was hypertension. People with headache had a higher prevalence of hypertension, rheumatic diseases, venous diseases, diabetes and a higher consumption of drugs. Therefore, headache, as one aspect of multimorbidity or a symptom of other diseases, could be an indicator of impaired well-being and poor health.

[Snoring as an sign of sleep disorders in 11- to 15-year-old school children--initial results of a Vienna epidemiologic study]. / Schnarchen als Leithinweis für Schlafstörungen bei Schulkindern zwischen 11 und 15 Jahren--Die ersten Ergebnisse der Wiener epidemiologischen Studie.

INTRODUCTION: The prevalence of snoring was evaluated in school children between 11 and 15 years of age. In addition to items reported by parents, children were asked to answer a questionnaire in order to receive information about the children's potential complaints, life style and school performance. METHOD: The study was performed in 21 randomly selected schools in the Vienna area. 1434 school children were interviewed by a questionnaire (mean age 12.5 years, median 13 years, 676 girls vs. 699 boys). The questionnaire consisted of 45 multiple-choice questions about the socioeconomic status, possible sleep disorders and signs or symptoms of obstructive sleep apneas (OSA). The questionnaire completed by parents was also used to calculate the Brouillette-Score from the items snoring, obstructed breaths and apneas. RESULTS: 5.2% (74/1434) of children and 6.9% (86/1259) of parents or caregivers reported about snoring (frequently or very frequently). There were no sex differences for the children's and the parents' questionnaire. None of the children had a clearly positive result (hint of OSA) from the Brouillette-Score whereas "suspicious OSA" was observed in 3.2% (40/1259). When frequent and very frequent snorers were compared with the other children, more mouth breathing during sleep (p < 0.00001), mouth dryness (p < 0.00005), headache (p < 0.0005), cigarette exposition at home (p < 0.001), smoking (p < 0.005), daytime naps (p < 0.005), crying out of sleep (p < 0.01), daytime tiredness (p < 0.05) und a higher body mass index (p < 0.05) could be observed in this group, in addition to the items reported by the parents. CONCLUSION: The prevalence of snoring is lower in our study than in other studies. No statistically significant sex differences were observed, both in the parents' and the children's questionnaire. In our study snoring seems to be a sign or symptom of different sleep disorders, and not only of OSA. A statistically significant correlation between snoring and anamnestic hints of sleep disorders underlines the need to ask concerned children themselves for observations potentially associated with sleep disorders. Results of the Brouillette-Score could not be used to identify sleep disorders in our study.

Self-reported organic and nonorganic sleep problems in schoolchildren aged 11 to 15 years in Vienna.

PURPOSE: To estimate the prevalence of self-reported sleep problems, to examine associations among demographic characteristics, familial factors, and sleep problems, and to investigate the association between the symptoms of obstructive sleep apnea (OSA) and nonorganic sleep disorders. METHODS: An anonymous questionnaire with 22 questions was designed. 332 schoolchildren (aged 11-15 years, mean age 12 years and 9 months; median, 12 years; 56% female, 44% male) from two high schools in Vienna were investigated with regard to self-reported symptoms characteristic for obstructive sleep apnea and for parasomnia/insomnia. Data were analyzed by definition of three groups (problem, occasional problem, and nonproblem sleepers, and by calculation of an insomnia/parasomnia sum score). Statistical analysis included nonparametric tests (Mann Whitney-U and Kruskal), Pearson correlation test, and multiple regression analysis. RESULTS: Twelve percent reported at least one sleep problem every night, 76% reported occasional sleep problems, and 12% had no sleep problems. Girls were affected more frequently than boys (p <.01). Children with sleep problems suffered more often from concentration difficulties (p <.05), daytime fatigue (p <.001), and daytime naps (p <.05). Children who snored had nightmares (10% vs. 2%, p <.01), night terrors (4% vs. 1.5%, p <.001), sleepwalking (1.4% vs. 1%, p <.05), and nocturnal awakening (16% vs. 5%, p <.01) more frequently. On multiple regression analysis, 23% of the variability of a defined parasomnia/insomnia sum score had the characteristic OSA symptoms of nocturnal sweating, dryness of the mouth, snoring, hyperactivity, and daytime fatigue. CONCLUSION: 12% of schoolchildren aged 11-15 years reported sleep problems almost every night. The children suffer from daytime fatigue, naps, and concentration difficulties. Nearly one-fourth of the symptoms of parasomnia/insomnia were associated with characteristic signs of OSA, suggesting the importance of a routine clinical investigation in children with so-called nonorganic sleep disorders.