Figure 2
From: Long-term CPAP treatment partially improves the link between cardiac vagal influence and delta sleep
Coherence analysis parameters between HF nu and delta power band signals. Panel a . Mean coherence value in SAHS patients before CPAP, with CPAP and healthy men (controls). Panel b . Mean gain value, expressed as the amplitudes’ ratio between delta power band and HFnu (Adelta/AHFnu), in SAHS patients before CPAP, with CPAP and healthy men (controls). Panel c . Mean delay, expressed in minutes (min), between the occurrence of modifications in HFnu and those in delta power band in SAHS patients before CPAP, with CPAP and healthy men (controls). SAHS: sleep apnea-hypopnea syndrome; CPAP: Continuous positive airway pressure. For each panel, comparisons were performed with controls. Values were expressed as mean ± standard errors. * P < 0,05. Coherence values of the link between the relative cardiac vagal predominance and delta power band were decreased in untreated and long-term nasal CPAP treated apneic patients compared to controls. Gain values between these both signals decreased in untreated apneic patients in comparison to controls while during long-term nasal CPAP treatment, gain values were similar to controls. Delay between occurrence of modifications in HFnu and those in the delta power band did not differ between untreated apneic patients and controls or between CPAP treated patients and controls.