Cooled ablation reduces pulmonary vein isolation time: results of a prospective randomised trial.

BACKGROUND: Currently, selection of the ablation catheter for pulmonary vein (PV) isolation is a matter of choice. OBJECTIVE: To evaluate the efficiency of cooled ablation for PV isolation. METHODS: A prospective randomised trial was carried out comparing the time required to disconnect each targeted PV using cooled ablation (open irrigation at 15 ml/min, group A) or standard temperature-controlled 4 mm tip catheter ablation (group B). The ablation parameter limit settings were 45 degrees C, 35 (5) W in group A, and 55 degrees C, 35 (5) W in group B. RESULTS: Thirty-six patients referred for a first atrial fibrillation (AF) ablation procedure were randomised to group A or group B (18 patients in each group). There were no significant differences in baseline characteristics between the groups. Bidirectional block was achieved in 61/61 PVs from group A (100%) and 59/61 PVs from group B (97%); p = NS. Time to PV disconnection was significantly shorter in group A than in group B (median (25th-75th centiles) 14 (5-28) min vs 19 (14-32) min, respectively; p = 0.003). Five asymptomatic PV stenoses were identified by MRI, all in group B (p = 0.05). After 1-year minimum follow-up, AF recurrences were less frequently documented in patients treated with cooled ablation (6% vs 33%; p = 0.05). CONCLUSION: Cooled ablation is more efficient than standard ablation in achieving PV isolation. Results obtained from this study also suggest a potential benefit of clinical efficacy and safety from cooled ablation, which should be further evaluated in larger clinical trials.

[Randomized clinical trial on the effectiveness of a postal reminder to increase tetanus-diphtheria vaccination coverage in the young adult population]. / Ensayo clínico aleatorizado acerca de la efectividad del recordatorio postal para aumentar la cobertura vacunal contra tétanos-difteria en población adulta joven.

OBJECTIVE: To evaluate the effectiveness of individual postal reminders compared with no action of any kind in increasing the tetanus-diphtheria immunization rate in the population aged between 24 and 30 years old in an area where a general population strategy was simultaneously being conducted through information posters on tetanus vaccination. METHOD: We performed an open, randomized clinical trial with parallel groups among the population aged 24-30 years old in a basic health area with 13,523 inhabitants over a 3-month period in 2005. There were 311 patients in the control group and 311 in the experimental group, after exclusion of individuals correctly vaccinated according to the computerized medical records system. The intervention evaluated was a postal reminder on tetanus vaccination. The response variable was the immunization rate due to the intervention. Other variables studied were sex, age, reason for seeking vaccination, compliance with the vaccination timetable, whether vaccination was rejected, and whether prior vaccination was verified. The statistical analysis consisted of Student's t-test and the chi2 test, with a confidence level of 95% (p < 0.05). RESULTS: Vaccination coverage among the general population at the end of 2005 was 75.6%. After the postal reminder, 22.2% of the control group and 40.5% of the experimental group were correctly vaccinated. CONCLUSIONS: Individual postal reminders sent to the population aged between 24 and 30 years is effective in increasing the immunization rate in this age group. Periodic reminders could help to ensure continuity in vaccination of the adult population.

Ensayo clínico aleatorizado acerca de la efectividad del recordatorio postal para aumentar la cobertura vacunal contra tétanos-difteria en población adulta joven / Randomized clinical trial on the effectiveness of a postal reminder to increase tetanus-diphtheria vaccination coverage in the young adult population

Objetivo. Evaluar la efectividad de los recordatorios postales individualizados frente a ningún tipo de intervención, para incrementar la tasa de inmunización con vacuna contra tétanos-difteria en la población de entre 24 y 30 años de edad, en un área donde simultáneamente se efectúa una estrategia poblacional general mediante carteles informativos acerca de la vacuna antitetánica. Método. Ensayo clínico, aleatorizado, abierto, con grupos paralelos, en una ABS de 13.523 habitantes, realizado en la población de 24-30 años, durante parte de 2005, con una muestra de 311 pacientes en el grupo control y 311 en el grupo intervenido, tras excluir los bien vacunados según el registro informático de la historia clínica. La intervención que se evalúa es el recordatorio postal acerca de la vacunación antitetánica y su repercusión debida a la intervención sobre la tasa de inmunización. También se recogieron datos sobre: sexo, edad, motivo para haber venido a vacunarse, cumplimiento de horario, si se rehusa la vacuna y si se comprueba que ya estaba bien vacunado previamente. Para el análisis estadístico se utilizaron la t de Student y el test de la x2, con un nivel de confianza del 95% (p < 0,05). Resultados. La cobertura vacunal poblacional a finales de 2005 ha sido del 75,6%. Tras el recordatorio postal estaba bien vacunado un 22,2% del grupo control y un 40,5% del grupo intervenido. Conclusiones. El recordatorio postal individualizado a la población de 24 a 30 años de esta área de salud es efectivo para incrementar la tasa de inmunización en este grupo de edad, y la realización periódica puede asegurar una continuidad en la vacunación de la población adulta

Objective. To evaluate the effectiveness of individual postal reminders compared with no action of any kind in increasing the tetanus-diphtheria immunization rate in the population aged between 24 and 30 years old in an area where a general population strategy was simultaneously being conducted through information posters on tetanus vaccination. Method. We performed an open, randomized clinical trial with parallel groups among the population aged 24-30 years old in a basic health area with 13,523 inhabitants over a 3-month period in 2005. There were 311 patients in the control group and 311 in the experimental group, after exclusion of individuals correctly vaccinated according to the computerized medical records system. The intervention evaluated was a postal reminder on tetanus vaccination. The response variable was the immunization rate due to the intervention. Other variables studied were sex, age, reason for seeking vaccination, compliance with the vaccination timetable, whether vaccination was rejected, and whether prior vaccination was verified. The statistical analysis consisted of Student's t-test and the x2 test, with a confidence level of 95% (p < 0.05). Results. Vaccination coverage among the general population at the end of 2005 was 75.6%. After the postal reminder, 22.2% of the control group and 40.5% of the experimental group were correctly vaccinated. Conclusions. Individual postal reminders sent to the population aged between 24 and 30 years is effective in increasing the immunization rate in this age group. Periodic reminders could help to ensure continuity in vaccination of the adult population

Dosimetría física y clínica en radiocirugía mediante Monte Carlo / Physical and clinical dosimetry in radisurgery using Monte Carlo

En radiocirugía la dosimetría física y clínica es más compleja que en técnicas radioterápicas de campos más extensos. Además, los planificadores convencionales, a pesar de su eficacia, mantienen ciertas incertidumbres. Por ello, la aparición de códigos basados en Monte Carlo tales como BEAM supone una alternativa al problema. Una vez simulado el acelerador se obtiene la información del haz de radiación, la cual puede ser analizada obteniéndose energías medias o distribuciones espectrales. Mediante el programa DOSXYZ, se consiguen distribuciones de dosis, tanto en fantomas como en pacientes. Este trabajo consiste en una serie de prácticas mediante las cuales se pretende conseguir un cierto manejo del paquete OMEGA que incluye los códigos BEAM y DOSXYZ. También se obtienen los Histogramas Dosis-Volumen calculados por Monte Carlo, mediante un programa desarrollado por nuestro grupo y se comparan con los dados por el planificador (AU)