Initial Orthostatic Hypotension: Underlying Physiology, Symptom Management, and the Patient Experience
AuthorSheikh, Nasia A.
Committee MemberExner, Derek
MetadataShow full item record
AbstractBackground: Initial orthostatic hypotension (IOH) is a common form of orthostatic intolerance defined by a large reduction in blood pressure (BP) within 15s of active standing resulting in symptoms of presyncope or a faint. Symptoms may occur numerous times within a single day, which significantly affects patients’ quality of life. However, there is limited data exploring IOH physiology and symptom management. Aims: We aimed to: (1) determine if the reflex underlying IOH had a refractory period; (2) better understand the physiology underlying IOH; (3) provide effective symptom management options; and (4) explore the patient experience living with IOH. Methods: A total of 26 participants enrolled in aims 1-3 and 16 in the fourth and final aim. Aims 1-3 involved series of randomized sit-to-stand maneuvers with and without interventions. Data are presented as mean±SD. Aim 4 consisted of one-on-one semi-structured interviews between the IOH participant and researcher probing into the patient experience living with IOH. Results: In aim 1, the drop in systolic BP (SBP) after standing was blunted following a short sit (-12±6 mmHg) compared to a long sit (-34±16 mmHg; p<0.001). In aim 2, the drops in SBP following the Serial 7 test (-26±12 mmHg; p=0.004), Cold Pressor test (-20±15 mmHg; p<0.001), and functional electrical stimulation (-28±12 mmHg; p=0.01) were significantly reduced compared to no intervention (-34±11 mmHg). In aim 3, the drop in SBP after standing was blunted following muscle pre-activation (-23±13 mmHg; p<0.001) and muscle post-tensing (-22±12 mmHg; p<0.001) compared to no intervention (-35±12 mmHg). In aim 4, an overriding theme was identified: Life, when simply standing up becomes a burden. Conclusions: Aim 1 illustrated that the reflex underlying IOH has a refractory period (<2 minutes) and a short sit blunts the IOH response. Aim 2 illustrated that both sympathetic activation and muscle activation plays an important role in mitigating the IOH BP response. Aim 3 concluded that both muscle pre-activation and post-tensing reduces the IOH BP drop and symptoms. Aim 4 illustrated that IOH negatively affects many aspects of patient life, including social, employment, and emotional aspects.
CitationSheikh, N. A. (2021). Initial Orthostatic Hypotension: Underlying Physiology, Symptom Management, and the Patient Experience (Unpublished master's thesis). University of Calgary, Calgary, AB.
University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.