Seasonal influence on sleep apnoea recorded daily by pacemakers.

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.

Differences in the prognostic value of the electrocardiographic pattern after cardiac resynchronization therapy according to age.

OBJECTIVES: In this cohort study, we analyzed if a specific pattern in three leads of the electrocardiogram (Rs in V1, Qr in aVL, or rS in I) was associated with outcomes after cardiac resynchronization therapy (CRT) depending on age. METHODS: Patients with CRT devices were included from January 2012 to April 2019. We divided the sample into 2 groups, those with age ≥ 75 years old and those younger. The primary endpoint was a composite of all-cause death and heart failure (HF) hospitalization at 1 year. RESULTS: We included 111 patients. Patients older than 75 years (26.1%, n = 29) had a significantly higher rate of hypertension and atrial fibrillation and received less frequently optimal medical therapy. The patterns were observed in 32 (39.0%) younger patients and 11 (37.9%) older patients. Patients who presented any of them had a lower incidence of the primary endpoint in the younger group (0 vs. 14%, p = 0.029), but not in the older group (9.1 vs. 27.8%, p = 0.24). The presence of a basal QRS duration greater than 160 ms was associated with a higher rate of the primary endpoint in the elderly (50 vs. 13%, p = 0.015), but not in the younger group (16.7 vs. 7.1%, p = 0.254). CONCLUSIONS: The presence of the selected patterns after CRT is associated with a lower incidence of all-cause death and hospitalization for HF in patients younger than 75 years, but not in those older than 75 years. Conversely, baseline QRS duration was associated with worse outcomes in older patients, but not in the younger group.