Article

Obstructive sleep apnea (OSA) is a prevalent form of sleep-disordered
breathing. Evidence suggests that OSA may lead to cardiac remodeling, although
the literature is equivocal. Previous literature suggests a high percentage of
individuals entering a cardiac rehabilitation (CR) program also have OSA. The
objective of this study was to determine whether resting hemodynamic variables
were altered in OSA subjects entering CR compared with those without OSA, as
determined by impedance cardiography. METHODS: Subjects entering an early
outpatient CR program were screened for OSA using an at-home screening device and
verified by a sleep physician. Subjects were divided into an OSA group (n = 48)
or a control group (n = 25) on the basis of the screening results. Hemodynamic
variables were measured during supine rest using impedance cardiography. A
6-minute walk test was performed to assess functional capacity. RESULTS: The
proportion of cardiac diagnoses was similar between groups. Overall, 66% of the
subjects were positive for OSA. Subject groups did not differ by age, body mass
index, heart rate, diastolic blood pressure, or functional capacity. Cardiac
output, cardiac index, stroke volume, contractility index, and left cardiac work
index were all significantly decreased in the OSA group compared with the control
group (P < .05). CONCLUSIONS: Findings suggest that OSA results in decreased
cardiac function in patients entering CR, likely because of pressure and volume
changes associated with apneic events. This may place those individuals at a
disadvantage in recovering from their cardiac event, and place them at increased
risk for secondary complications.

Langue : ANGLAIS