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Date of Award
Master of Science (MS)
Department of Kinesiology
The primary objective of this study was to examine the effects of obstructive sleep apnea (OSA) on resting hemodynamic variables pre- and post-cardiac rehabilitation (CR). Subjects were screened for OSA using an at-home screening device. Subjects were then divided into two design groups: subjects with likely OSA (OSA) and subjects without OSA (non-OSA). All patients had resting hemodynamic measurements recorded and performed a 6-minute walk test. Resting hemodynamics and 6-minute walk test were performed pre- and post-CR. The study was conducted at Rockingham Memorial Hospital in Harrisonburg, VA and Carilion Roanoke Community Hospital in Roanoke, VA where subjects completed standard early-outpatient (Phase II) Cardiac Rehabilitation. The sample consisted of 33 OSA subjects (age: 65.0 ± 12.4 years; AHI: 17.2 ± 12.3) and 12 non-OSA subjects (age: 63.7 ± 11.2 years; AHI: 1.8 ±1.3). Both the OSA and the non- OSA group had a significant improvement in BMI (p= 0.046) from baseline measurements to follow-up without a significant difference between groups. Both groups significantly improved 6-minute walk test performance (p<0.0001) from baseline to follow-up, with the OSA group having significantly higher values at both time points. The OSA group had significantly lower cardiac index values (p=0.018), ejection fraction values (p=0.039), and contractility index values (p=0.008) when compared to the non OSA group at baseline and follow-up. The OSA group had significantly higher systemic vascular resistance index values (p=0.027) when compared to the non-OSA group at baseline and follow-up. There was no significant effect for time or group by time with respect to any other variable. CR can facilitate in BMI improvement, while potentially improving vi cardiovascular fitness in patients. CR did not improve resting hemodynamic variables, regardless of OSA presence. However, subjects with OSA appear to have diminished cardiac function when compared to non-OSA subjects, manifesting through increased systemic vascular resistance index and decreased contractility index, cardiac index, and ejection fraction.
Shafer, Brooke Marie, "The implications of undiagnosed obstructive sleep apnea on resting hemodynamic variables in cardiac rehabilitation patients" (2013). Masters Theses. 322.