OBJECTIVE

To assess the incidence and risk factors of Cheyne-Stokes respiration (CSR) in patients with chronic heart failure (CHF).

MATERIAL AND METHODS

There were 928 consecutive adults with chronic heart failure NYHA class II-IV. After excluding the patients with ejection fraction over 50%, respiratory failure and comorbidities associated with high risk of obstructive and central sleep apnea, we recruited 47 patients. All patients underwent standard examination including echocardiography and 24-hour ECG monitoring, arterial blood gas analysis, 6-minute walk test with analysis of heart rate, respiratory rate and arterial saturation (SpO₂) before and after walking, as well as cardiorespiratory monitoring during sleep with analysis of apnea/hypopnea index (AHI). Questionnaires were used to assess quality of life.

RESULTS

CSR was found in 58% of patients. Patients with CSR were characterized by higher breathing rate after exercise, higher blood pH, E/e’ value, more significant decrease in mean SpO₂ and prolonged desaturation during sleep. We found significant correlations between VTI and mean SpO₂ (R=0.664, p=0.001), E/e’ and AHI (R=0.475, p=0.034), arterial PaCO₂ and AHI (R=–0.513, p=0.006), distance in 6-minute walk test and AHI (R=–0.602, p=0.002). Relationship between AHI and E/e’ was significant in multivariate analysis (p=0.042).

CONCLUSION

Cheyne-Stokes respiration in CHF patients with reduced left ventricular ejection fraction was detected in 58% of cases after excluding other potential causes of sleep apnea. Cheyne-Stokes respiration was associated with higher blood pH, E/e’, respiratory rate after exercise, lower mean SpO₂ and prolonged desaturation <90% during sleep.