RESUMO
PURPOSE: Obstructive sleep apnoea (OSA) and cardiac conduction disorders are pathologies with a rising prevalence due to increased life expectancy. Upper airway patency is affected by environmental factors that may be associated with seasonal periods. The ability to record the degree of nocturnal apnoea on a daily basis may provide a more accurate picture of seasonal variability. METHODS: This study used an observational, cross-sectional design recruiting consecutive patients with Sorin/Livanova/Microport® pacemakers. The study assessed the seasonal influence on the daily degree of nocturnal apnoea over a minimum period of 180 days. The respiratory events were recorded using a pacemaker-integrated detection algorithm based on transthoracic impedance variation. A generalised linear repeated measure mixed model was used to study the seasonal effect. RESULTS: A sample of 101 subjects with a mean of 227 valid nights was compiled. Summer was associated with higher RDI (respiratory disturbance index) values and winter with lower values. The mean daily RDI ratio in summer was 1.099 times higher than in winter. CONCLUSIONS: Slight seasonal influences on the degree of nocturnal apnoea were detected through the daily observation of an unselected sample of pacemaker wearers. The degree of apnoea is higher in warmer months and lower in colder months.
