Determinants of Behavioral Alertness in Adults with Heart Failure

Study objectives: The primary objective of this study was to describe characteristics of sleep across the three domains of sleep quality, daytime sleepiness, and behavioral alertness in community-dwelling adults with heart failure. The secondary objective was to identify modifiable factors associated with behavioral alertness.

Methods: A sample of 280 adults with chronic heart failure was enrolled. Widely used, validated, and sensitive measures of sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness Scale, Stanford Sleepiness Scale), and behavioral alertness (Psychomotor Vigilance Test [PVT]) were collected at baseline, 3 and 6 months. Sociodemographic and clinical characteristics, including exercise, were measured at baseline.

Results: Participants were primarily male and functionally compromised with a mean left ventricular ejection fraction of 35 percent. The majority of the sample (73%) reported poor sleep quality. The mean (± SD) Epworth Sleepiness Scale score was low (7.0 ± 4.6), indicating they did not perceive daytime sleepiness. In contrast, behavioral alertness was relatively poor as evidenced by a slow PVT mean response time (3.09 ± 0.76). Participants who reported exercising at least one hour in the past week were more alert and had faster response times than those reporting no exercise.

Conclusions: Although sleep quality was poor and behavioral alertness was compromised, these heart failure patients did not feel sleepy. Exercise may help to promote behavioral alertness and reduce daytime sleepiness in adults with heart failure.