Background Autonomic dysfunction contributes to atrial fibrillation (AF). Objective We hypothesized that polysomnogram (PSG)-based heart rate variability (HRV) autonomic function biomarkers are associated with incident AF and these associations are modified by measures of sleep disordered breathing (SDB). Methods 2350 participants of a multi-center prospective study (Outcomes of Sleep Disorders in Older Men Study) without baseline AF underwent sleep studies with incident adjudicated AF follow up (8.0 ± 2.6 years). Cox proportional hazard models were used to analyze sleep study-ECG spectral HRV indices [low and high frequency power (LF, HF), LF/HF] and time domain indices [mean of normal to normal beats (MNN), short and long term variability (STV, LTV) and STV/LTV] and premature atrial contractions (PACs) and incident AF (HR and 95% CI). Statistical interactions between HRV and SDB were examined. Models were adjusted for age, race, body mass index, waist circumference, cardiac medications, co-morbid diseases, alcohol use and study site. Results Lower LF/HF and lower LF were associated with higher AF incidence (LF/HF Q1 vs. Q4: 1.46, 1.02–2.08, LF Q1 vs. Q4: 1.46, 1.02–2.10). Higher STV/LTV was associated with an increased risk of AF (p-trend= 0.028). The highest PAC quartile had a 3-fold increased AF risk (2.99, 1.94–4.62) compared to the lowest quartile. A significant interaction of obstructive apnea was observed in the LF-AF relationship (0.045). Conclusions Sleep-related reduced sympathovagal balance (LF/HF) and increased atrial ectopy are independently associated with future AF; a relationship modified by obstructive apnea.

Ultrasound-guided CVC placement and positioning with a minor modification in technique reduced the use of bedside CXR and reduced the time to use of the CVC.

This article reviews the use of thoracic ultrasound in the intensive care unit (ICU). The focus of this article is to review the basic terminology and clinical applications of thoracic ultrasound. The diagnostic approach to a breathless patient, the blue protocol, is presented in a simplified flow chart. The diagnostic application of thoracic ultrasound in lung parenchymal and pleural diseases, role in bedside procedures, diaphragmatic assessment, and lung recruitment are described. Recent updates discussed in this review help support its increasingly indispensable role in the emergent and critical care setting.

No abstract

No abstract