Decrease in QRS amplitude in juvenile female competitive athletes during the initial twenty-one months of intensive training

Background: The aim of this project was to study changes in QRS amplitude in junior female athletes during the initial twenty-one months of competitive training programme in aerobic gymnastics. Methods: Somatometric parameters, heart rate (HR), blood pressure (BP) and 12-lead ECGs were recorded in 12 female athletes, aged 13-17 years (average 13.8) at 3-month intervals over a period of 21 months. The Sokolow-Lyon index (SLI) and the maximum QRS spatial vector magnitude (QRSmax), approximated from RV5, RaVF and SV2 voltages, were analyzed. Results: The mean values of QRSmax and SLI decreased gradually during the study period. The difference between the mean QRSmax values at the beginning and at the end of the study period was -0.8 mV (30.8%), p < 0.001, and between the initial and final values of SLI was -0.6 mV (24%), p < 0.001. The somatometric parameters changed only slightly, HR and systolic BP values did not change significantly. Conclusions: This study showed that 21 months of competitive aerobic gymnastics training led to a decrease in the QRSmax magnitude. This finding is in contrast with the classical hypothesis on the ECG diagnostics of LVH and is in agreement with an alternative hypothesis on the relative voltage deficit during the early stage of LVH development. (Cardiol J 2007; 14: 260-265

Frailty and incident heart failure in older men: the British Regional Heart Study.

OBJECTIVE: Frailty and heart failure (HF) are cross-sectionally associated. Published longitudinal data are very limited. We sought to investigate associations between frailty and incident HF. METHODS: Prospective study of 1722 men, examined at age 72-91 years. Scores based on the Fried phenotype, Gill index and a novel frailty score, based on the Health Ageing and Body Composition Battery, incorporating slow walking speed, low chair-stand time and subjective difficulty with balance, were calculated. Associations between these scores and incident HF were analysed with Cox proportional hazard modelling. RESULTS: 1445 men with frailty data and without prevalent HF were included. 99 developed HF (mean follow-up 6.1 years). Men scoring 3/3 on our novel frailty score had elevated risk of incident HF (HR 2.77, 95% CI 1.25 to 6.15), which persisted after adjustment for established risk factors and interleukin-6 (HR 3.14, 95% CI 1.35 to 7.31). This risk remained increased, although attenuated, after excluding HF events within 2 years of baseline (HR 2.05, 95% CI 0.61 to 6.92). The frailty phenotype showed a non-significant association with HF (age-adjusted HR 1.92, 95% CI 0.99 to 3.73), which was further attenuated after adjustment for prevalent coronary heart disease and Body mass index (HR 1.60, 95% CI 0.81 to 3.15). Gill-type scores were weakly associated with HF risk after these adjustments (HR 1.31, 95% CI 0.47 to 3.70). CONCLUSION: In these older men, the combination of slow walk speed, low sit-stand time and balance problems were associated with high risk of incident HF, independent of established risk factors and inflammatory markers. However, undiagnosed HF at baseline may still be a confounder. There is a differential association between aspects of the frailty phenotype and incident HF

Investigating regional differences in short-term effects of air pollution on daily mortality in the APHEA project: a sensitivity analysis for controlling long-term trends and seasonality.

Short-term effects of air pollution on daily mortality in eight western and five central-eastern European countries have been reported previously, as part of the APHEA project. One intriguing finding was that the effects were lower in central-eastern European cities. The analysis used sinusoidal terms for seasonal control and polynomial terms for meteorologic variables, but this is a more rigid approach than the currently accepted method, which uses generalized additive models (GAM). We therefore reanalyzed the original data to examine the sensitivity of the results to the statistical model. The data were identical to those used in the earlier analyses. The outcome was the daily total number of deaths, and the pollutants analyzed were black smoke (BS) and sulfur dioxide (SO(2)). The analyses were restricted to days with pollutant concentration < 200 microg/m(3) and < 150 microg/m(3) alternately. We used Poisson regression in a GAM model, and combined individual city regression coefficients using fixed and random-effect models. An increase in BS by 50 microg/m(3) was associated with a 2.2% and 3.1% increase in mortality when analysis was restricted to days < 200 microg/m(3) and < 150 microg/m(3), respectively. The corresponding figures were 5.0% and 5.6% for a similar increase in SO(2). These estimates are larger than the ones published previously: by 69% for BS and 55% for SO(2). The increase occurred only in central-eastern European cities. The ratio of western to central-eastern cities for estimates was reduced to 1.3 for BS (previously 4.8) and 2.6 for SO(2) (previously 4.4). We conclude that part of the heterogeneity in the estimates of air pollution effects between western and central-eastern cities reported in previous publications was caused by the statistical approach used and the inclusion of days with pollutant levels above 150 microg/m(3). However, these results must be investigated further

Short term effects of ambient sulphur dioxide and particulate matter on mortality in 12 European cities : results from time series data from the APHEA project

Objectives: To carry out a prospective combined quantitative analysis of the associations between all cause mortality and ambient particulate matter and sulphur dioxide. Design: Analysis of time series data on daily number of deaths from all causes and concentrations of sulphur dioxide and particulate matter (measured as black smoke or particles smaller than 10 ìm in diameter (PM10)) and potential confounders. Setting: 12 European cities in the APHEA project (Air Pollution and Health: a European Approach). Main outcome measure: Relative risk of death. Results:In western European cities it was found that an increase of 50 ìg/m3 in sulphur dioxide or black smoke was associated with a 3% (95% confidence interval 2% to 4%) increase in daily mortality and the corresponding figure for PM10 was 2% (1% to 3%). In central eastern European cities the increase in mortality associated with a 50 ìg/m3 change in sulphur dioxide was 0.8% (−0.1% to 2.4%) and in black smoke 0.6% (0.1% to 1.1%). Cumulative effects of prolonged (two to four days) exposure to air pollutants resulted in estimates comparable with the one day effects. The effects of both pollutants were stronger during the summer and were mutually independent. Conclusions:The internal consistency of the results in western European cities with wide differences in climate and environmental conditions suggest that these associations may be causal. The long term health impact of these effects is uncertain, but today's relatively low levels of sulphur dioxide and particles still have detectable short term effects on health and further reductions in air pollution are advisable

Zmniejszenie amplitudy zespołu QRS u młodych kobiet uprawiających sport podczas początkowego okresu intensywnego treningu fizycznego trwającego 21 miesięcy

Wstęp: Celem niniejszego badania była ocena zmian wartości amplitudy napięcia zespołu QRS u młodych kobiet uprawiających sport podczas 21-miesięcznego okresu intensywnego treningu rywalizacyjnego w zakresie aerobiku gimnastycznego. Metody: Przez okres 21 miesięcy w grupie uprawiających sport 12 młodych kobiet w wieku 13-17 lat (średnio 13,8 roku) w co 3-miesięcznych odstępach analizowano parametry antropometryczne, częstość akcji serca, ciśnienie tętnicze oraz wybrane wskaźniki 12-odprowadzeniowego badania elektrokardiograficznego. Analizie poddano wyliczone wcześniej: wskaźnik Sokołowa- Lyona (SLI) oraz wartość tak zwanego maksymalnego wektora przestrzennego zespołu QRS (QRSmax), ocenionego na podstawie wartości amplitudy załamków: R w odprowadzeniu V5 (RV5), R w odprowadzeniu aVF (RaVF) oraz S w odprowadzeniu V2 (SV2). Wyniki: Średnia wartość QRSmax oraz SLI stopniowo zmniejszyła się podczas trwania okresu treningu. Różnica między średnią wartością QRSmax na początku oraz na końcu badania wynosiła: -0,8 mV (30,8%, p < 0,001), zaś pomiędzy początkową i końcową wartością SLI: -0,6 mV (24%, p < 0,001). Parametry antropometryczne uległy jedynie niewielkiej zmianie, częstość akcji serca oraz skurczowe ciśnienie tętnicze nie zmieniły się w istotny sposób. Wnioski: W badaniu wykazano, że wdrożenie trwającego 21 miesięcy rywalizacyjnego treningu w zakresie aerobiku gimnastycznego spowodowało zmniejszenie wartości maksymalnego wektora przestrzennego zespołu QRS. Wyniki te są odmienne niż klasyczna hipoteza, na której opiera się elektrokardiograficzna diagnostyka przerostu lewej komory oraz zgodne z założeniami hipotezy alternatywnej, mówiącej o relatywnym obniżeniu wartości woltażu podczas wstępnej fazy rozwoju przerostu lewej komory. (Folia Cardiologica Excerpta 2007; 2: 477&#8211;484