Background & objectives: Heart failure is considered as a major cause of hospitalization. Many studies have shown association between sleep-related breathing disorders and heart failure. It has been shown that the relationship between nocturnal hypoxia and left ventricular dysfunction can cause significant morbidity and mortality in patients with congestive heart failure (CHF ). Accordingly, treatment of sleep related breathing disorders (SRBD) can give rise to improvement in CHF treatment too. This study surveys the prevalence of sleep disorder in stable heart failure patients regardless of ejection fraction.

  Methods : This study was a descriptive-analytical study. One hundred and eight patients with heart failure disease were studied. A questionnaire consisting of two parts (part I consistent of demographic information and part II consistent of sleep disorders) and clinical examination (pulse oximetery and echocardiography) were used for collection of data. The data were analyzed with SPSS statistical software using descriptive and analytical tests including the chi-square, Pearson correlation and ANOVA.

  Results: Fifty six persons (51.9%) of patients were female and 52 persons (48.1%) were male with mean age of 65.42 ± 11 years. In total sleep duration, 95 patients (88%) had nocturnal hypoxemia . There was correlation between arterial oxygen desaturation at night and ejection fraction .

  Conclusion : This study confirmed strong associations between nocturnal hypoxia and left ventricular dysfunction and SRBD should be considered in clinical treatment of systolic heart failure.