Introduction: From 30 to 50% of patients with chronic and stable heart failure with systolic ventricular dysfunction may suffer sleep related respiratory disorders, mostly central apnea and Cheyne Stokes respiratory pattern. These disorders have been related with cyclic sympathetic hyperactivity and greater occurrence of ventricular arrhythmias. Our objective was to document the prevalence of central apnea among patients with systolic dysfunction and study its association with the presence of arrhythmias during sleep, mid-term clinical follow up was performed in such a matter.
Methods and Materials: We selected 81 consecutive patients in a prospective manner that were clinically stable during the last month (57,1 +/- 1,5 years, Left Ventricular Ejection Fraction 29,4 +/- 1,3%, Male 87%). Nocturnal polysomnography with simultaneous holter cardiac monitoring was performed. We analyzed the heart rate, the presence of cardiac pauses and the occurrence of premature beats or tachycardia in patients diagnosed with central sleep apnea (group I) and in patients without respiratory disorders (group II) observed in the polysomnography test and compared the results. The need for hospitalization because of cardiac deterioration was registered.
Results: In our cohort of patients, 31,6% were diagnosed with central sleep apnea. There were no significant differences between group I and group II taking into account sex, age, etiology of heart failure (52 vs 36,2% ischaemic, 36 vs 44,8% idiopathic), NYHA class function or pharmacologic treatment. There were no differences in the median, maximal or minimal heart rate between groups, neither in the presence of supraventricular premature beats or supraventricular tachycardia. There was a greater incidence of ventricular premature beats both isolated (p = 0,001) and paired (p = 0,004) in group I as well as ventricular tachycardia (p = 0,043) and cardiac pauses >2 seconds (p = 0,027). Group I 96% vs Group II 42,4% (p < 0,001) required hospitalization on follow up.
Conclusions: More than one third of patients with stable and chronic systolic heart failure suffer sleep apnea. In those patients nocturnal ventricular arrhythmias and hospitalization are more frequent.