Cardiac arrhythmias and sleep-disordered breathing in patients with heart failure

Abstract

The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients.

Figure 1

Polysomnography (3 min) with central sleep apnea (A) and obstructive sleep apnea (B) Note the absence of chest efforts and abdominal movements in the absence of oronasal airflow in central sleep apnea but not in obstructive sleep apnea (arrows). Also, note the pronounced decrease in O₂-saturation following each apnea episode.

Figure 2

Relationship between heart failure, sleep-disordered breathing and cardiac arrhythmias.

Figure 3

Stored implantable cardioverter defibrillator (ICD) electrocardiogram (ECG) showing a spontaneous episode of rapid polymorphic ventricular tachycardia, which is terminated after 9 s by the first 36 Joules ICD shock. The black arrows indicate that it is a continuous ECG tracing. The red arrows mark the termination of ventricular fibrillation by a 36 Joules ICD shock.