Sympathetic Nerve Activity Predictors in Patients With Chronic Obstructive Pulmonary Disease

"For assessment sympathovagal balance (SVB), HRV and dBPV will be analysed using a 3-lead electrocardiogram (sampling rate 1000Hz) and a continuous non-invasive arterial blood pressure signal (CNAP® technology, sampling rate 100Hz). HRV (ms2 based on continuously recorded variability in RR intervals) and (diastolic) BPV (expressed as mmHg2 based on continuously recorded variability in diastolic BP) will be computed by time domain analysis and by frequency domain analysis and presented as the high frequency component (HF; 0.15-0.4 Hz), low frequency component (LF; 0.04-0.15 Hz), their relative ratio (LF/HF), and the very low frequency component (VLF; 0.0-0.04 Hz) for both HRV and dBPV .~Muscle SNA will be recorded via a tungsten microelectrode carefully placed in the peroneal nerve. Plasma catecholamines will also be assessed."

OSA is defined as apnoea-hypopnoea index \[AHI\] \>15/h and obstructive apnoea index \[OAI\] \>5/h) and sleep architecture

(defined as tricuspid annular plane systolic excursion ≤14 mm) and pulmonary arterial pressure (PAsys) using transthoracic echocardiography

Respiratory Muscle strength and function testing as previously established by our group and Assessment of daytime hypoxia (PaO2 \<55 mmHg) and hypercapnia (PaCO2 \>45 mmHg) using capillary blood gas analysis.

Based on blood samples taken.