AHI was higher using the AASM 2012 scoring rules due to a less strict definition of hypopnea. Data on the prognostic effects of CSR in patients with HF and the benefits of treatment are mostly based on the AASM 2007 recommended rules, so differences between these and the newer version need to be taken into account.

This study investigated the haemodynamic effects of adaptive servoventilation (ASV) in heart failure (HF) patients with Cheyne-Stokes respiration (CSR) versus healthy controls. Twenty-seven HF patients with CSR and 15 volunteers were ventilated for 1 h using a new ASV device (PaceWave™). Haemodynamics were continuously and non-invasively recorded at baseline, during ASV and after ventilation. Prior to the actual study, a small validation study was performed to validate non-invasive measurement of Stroke volume index (SVI). Non-invasive measurement of SVI showed a marginal overall difference of -0.03 ± 0.41 L/min/m(2) compared to the current gold standard (Thermodilution-based measurement). Stroke volume index (SVI) increased during ASV in HF patients (29.7 ± 5 to 30.4 ± 6 to 28.7 ± 5 mL/m(2), p < 0.05) and decreased slightly in volunteers (50.7 ± 12 to 48.6 ± 11 to 47.9 ± 12 mL/m(2)). Simultaneously, 1 h of ASV was associated with a trend towards an increase in parasympathetic nervous activity (PNA) in HF patients and a trend towards an increase in sympathetic nervous activity (SNA) in healthy volunteers. Blood pressure (BP) and total peripheral resistance response increased significantly in both groups, despite marked inter-individual variation. Effects were independent of vigilance. Predictors of increased SVI during ASV in HF patients included preserved right ventricular function, normal resting BP, non-ischaemic HF aetiology, mitral regurgitation and increased left ventricular filling pressures. This study confirms favourable haemodynamic effects of ASV in HF patients with CSR presenting with mitral regurgitation and/or increased left ventricular filling pressures, but also identified a number of new predictors. This might be mediated by a shift towards more parasympathetic nervous activity in those patients.

When monitoring BP in HF patients, overall BP monitoring using PTT is comparable to oscillometry for a period of 2 h (including a 1-h ASV phase). However, PTT shows a tendency to underestimate BP over time and during ASV.