Level V, expert opinion.

Background: Implantable cardioverter defibrillators (ICDs) are increasingly employed in patients affected by congestive heart failure (CHF) and sleep disordered breathing (SDB) is frequent in this population. Hypothesis: To investigate SDB prevalence and influence on appropriate ICD discharges in CHF patients. Methods: A total of 22 consecutive ICD patients with systolic CHF (left ventricular ejection fraction [LVEF]<45%) were studied by polysomnography. Results: A total of 17 (77.2%) showed SDB (apnea-hypopnea index [AHI] 10 events/hour). After controlling for LVEF and New York Heart Association (NYHA) class, AHI and severity of hypoxia during sleep results correlated to appropriate ICD discharges (r = 0.718; P < .001, r = −0.619; P = .003, respectively). Conclusions: Sleep disordered breathing is frequent in ICD recipients due to left systolic ventricular dysfunction and may increase the risk of ventricular arrhythmia and appropriate ICD discharges.

Cross-sectional survey, Level III.

The prevalence and the factors influencing respiratory symptoms and asthma in recreational athletes are still poorly defined. The aim of the study is to estimate the prevalence of self-reported asthma and respiratory symptoms in a sample of Italian amateur athletes compared with the general population. We also intend to estimate the association between asthma, the type of exercise and the environment where it was practised. The study population included athletes (A) practising sports in the city of Bozen (northern Italy) (n 0 1022). A random sample from the general population (GP) (n 0 2166) was used as the control group. All participants filled in a questionnaire including items regarding asthma, respiratory symptoms and type of sporting activities. Associations between exposure variables and outcomes, adjusted for potential confounding factors, were estimated using logistic regression. Our findings revealed that the prevalence of asthma (''Have you ever had asthma?'') was lower among A (4.0%) than in the GP (11.0%, P B 0.001). Similar figures were recorded for current asthma (asthma in the past plus an asthma attack or wheezing in the last 12 months and/or current use of medication for asthma) (A 3.0%, GP 4.8%, P 0 0.044) and for respiratory symptoms (A 3.9%, GP 18.9%, P B 0.001). Comparisons within the sample of athletes, taking indoor sports as a reference category, revealed that performing outdoor sports in spring and summer was associated with a higher risk of asthma, the same however was not true for outdoor sports performed in winter (adjusted OR 0 2.8, 95% CI 0 1.1Á7.5). Where OR 0 Odds Ratio and CI 0 Confidence Interval. The risk of developing symptoms after exercise was higher for outdoor sports practised in the mild or cold seasons (adjusted OR 0 4.6, 95% CI 0 1.0Á21.3 and adjusted OR 0 11.9, 95% CI 0 2.5Á56.1, respectively). Training for more than five hours a week was associated with a lower prevalence of asthma than training for less (adjusted OR 0 0.45, 95% CI 0 0.2Á0.9). Finally, no relationship emerged between type of exercise, asthma and respiratory symptoms. The results of this study indicate that asthma is less common in amateur athletes than in the general population and that the risk of asthma and respiratory symptoms is associated more with outdoor than with indoor sports, but not with any particular type of exercise.

No abstract