Comparison of actigraphic and subjective measures of sleep in implantable cardioverter defibrillator and coronary artery disease patients.

Background: Cardiac patients frequently have insomnia symptoms that may pose risk for future cardiac events. Poor sleep relates to hyperarousal, anxiety and depression, and the incidence of hypertension and myocardial infarction.

Hypothesis: The authors hypothesized that implantable cardioverter defibrillator (ICD) patients would have poorer sleep than coronary artery disease (CAD) patients related to hypervigilance for device functioning and shock discharge.

Methods: Authors investigated sleep efficiency and sleep latency in a sample of 60 patients (n = 30 CAD and n = 30 ICD) without obstructive sleep apnea at the University of Florida & Shands Hospital. For 14 days, participants completed a sleep diary. Additionally, half of the total sample also used actigraphy to objectively measure their sleep. Measures of somatic hypervigilance and psychosocial distress were administered.

Results: Using actigraphy, mean sleep efficiency was poorer (69.76%) in CAD patients compared with ICD patients (82.80%). This difference was highly significant, F₁,₂₇ = 16.840, P < 0.001. CAD patients also had shorter mean total sleep times per sleep diaries compared with ICD patients (336.19 minutes or 5.60 hours, 430.65 minutes or 7.18 hours, respectively), F₁,₂₇ = 15.908, P < 0.001.

Conclusions: The finding that ICD patients slept more efficiently than CAD patients is surprising given that CAD patients had higher ejection fractions and no concerns about ICD shocks. This difference cannot be accounted for by differences in hypervigilance, depression, anxiety, or physical activity. Results suggest that CAD patients may have more sleep problems and may warrant increased research attention.