Prevalence and profile of sleep disordered breathing amongst patients with congestive heart failure

Introduction: It has been observed that since heart failure is highly prevalent and central sleep apnea (CSA) is common in patients with a failing heart, heart failure is the commonest cause of CSA in the general population.

Aims & Objectives: The present study was undertaken with the purpose of finding prevalence of sleep disordered breathing (SDB) in patients of heart failure and also to find the association of severity of SDB with severity of heart failure.

Material & Methods: Forty patients suffering from systolic heart failure were selected on random basis. All these patients underwent complete evaluation of history, physical examination and overnight polysomnography. The patients were divided into two groups, namely group 1 and group 2, on the basis of polysomnography. Group 1 consisted of 17 patients who did not have sleep disordered breathing i.e. AHI (central or obstructive) < 5. Group 2 consisted of 23 patients who had sleep disordered breathing i.e. AHI (central or obstructive) > 5. Comparison of biochemical profile and sleep parameters was made between group 1 and group 2 and results analyzed.

Observations: Aetiology of heart failure was ischemic heart disease in 34 patients, viral myocarditis in 3 patients and postpartum cardiomyopathy in 3 patients. Total prevalence of CSA in heart failure was 57.5%. Prevelance in males and females was 47.6% and 68.42% respectively. There was a significant difference in O2 desaturation index, minimum O2, arousal index, total sleep time, AHI (central), sleep efficiency and wake O2 amongst the two groups. A negative correlation was observed between ejection fraction and O2 desaturation index, AHI (central), and arousal index. A positive correlation was found between ejection fraction and wake O2.

Conclusions: A fairly high prevalence of sleep-disordered breathing (57.5%) was found in patients of heart failure in the present study. With increasing severity of HF a significant worsening of CSA-CSR was observed. The treatment of CSA-CSR may prevent the worsening status of H F. Hence long term randomized and controlled interventions are required to further substantiate these fact.