Table 2. Clinical features that favour normal ventilation vs. OSA vs. CSA-CSR in heart failure.
| Normal ventilation during sleep |
| Either gender |
| Normal BMI and upper airway appearance |
| Able to sleep flat in bed comfortably |
| Absence of snoring |
| Absence of apneas |
| Absence of daytime fatigue or sleepiness |
| Absence of hospital admissions for acute pulmonary edema |
| Normal PaCO2 |
| Obstructive sleep apnea (OSA) |
| Male predominance |
| Elevated BMI or abnormally small upper airway |
| Regular snorer |
| Witnessed obstructive apneas |
| Excessive daytime sleepiness |
| Systemic hypertension on treatment |
| Diastolic and possibly moderately severe left ventricular systolic failure |
| Normal to high PaCO2 |
| Central sleep apnoea with Cheyne stokes respiration (CSA-CSR) |
| Male predominance |
| Normal BMI with normal upper airway |
| Orthopnea and paroxysmal nocturnal dyspnoea |
| May snore at peak of hyperventilation |
| Witnessed central apnoeas |
| Advanced heart failure of any cause |
| Recurring episodes of pulmonary oedema |
| Normal to low PaCO2 |
| Abates in severity with more intense CHF treatment |
| Periodic breathing on cardiopulmonary exercise testing |
OSA, obstructive sleep apnea; CSA-CSR, central sleep apnoea with cheyne stokes respiration; CHF, congestive heart failure.