Introduction: High intensity interval exercise (HIIT) is performed widely. However, there is a gap in knowledge regarding the acute cerebrovascular response to low-volume HIIT. Our objective was to characterize the middle cerebral artery blood velocity (MCAv) response during an acute bout of low-volume HIIT in young healthy adults. We hypothesized MCAv would decrease below baseline (BL) 1) during HIIT, 2) immediately following HIIT, 3) and 30-minutes after HIIT. As a secondary objective, we investigated sex differences in the MCAv response during HIIT. Methods: Twenty-four young healthy adults completed HIIT (12 male, age 25 (SD 2)). HIIT included 10-minutes of 1-minute high intensity (~70% estimated maximal watts) and active recovery (10% estimated maximal watts) intervals on a recumbent stepper. MCAv, mean arterial pressure (MAP), heart rate (HR), and end tidal carbon dioxide (PETCO2), were recorded at BL, during HIIT, immediately following HIIT, and 30-minutes after HIIT. Results: Contrary to our hypothesis, MCAv remained above BL during HIIT. MCAv peaked at minute 3 then decreased concomitantly with PETCO2. MCAv was lower than BL immediately following HIIT (p < 0.001). Thirty-minutes after HIIT, MCAv returned to BL (p = 0.47). Compared to men, women had a higher MCAv at BL (p = 0.001), during HIIT (p = 0.009), immediately following HIIT (p = 0.004) and 30-minutes after HIIT (p = 0.001). Conclusions: MCAv did not decrease below BL during low-volume HIIT. However, MCAv decreased below BL immediately following HIIT and returned to resting values 30-minutes after HIIT. MCAv also differed between sex.

Background The primary aim of this study was to characterize the middle cerebral artery blood velocity (MCAv) dynamic response to an acute bout of exercise in humans at 3‐ and 6‐months poststroke. As a secondary objective, we grouped individuals according to the MCAv dynamic response to the exercise bout as responder or nonresponder. We tested whether physical activity, aerobic fitness, and exercise mean arterial blood pressure differed between groups. Methods and Results Transcranial Doppler ultrasound measured MCAv during a 90‐second baseline followed by a 6‐minute moderate intensity exercise bout. Heart rate, mean arterial blood pressure, and end‐tidal CO 2 were additional variables of interest. The MCAv dynamic response variables included the following: baseline, time delay, amplitude, and time constant. Linear mixed model revealed no significant differences in our selected outcomes between 3‐ and 6‐months poststroke. Individuals characterized as responders demonstrated a faster time delay, higher amplitude, and reported higher levels of physical activity and aerobic fitness when compared with the nonresponders. No between‐group differences were identified for baseline, time constant, or exercise mean arterial blood pressure. In the nonresponders, we observed an immediate rise in MCAv following exercise onset followed by an immediate decline to near baseline values, while the responders showed an exponential rise until steady state was reached. Conclusions The MCAv dynamic response profile has the potential to provide valuable information during an acute exercise bout following stroke. Individuals with a greater MCAv response to the exercise stimulus reported statin use and regular participation in exercise.

Blood flow regulation is impaired in people with stroke. However, the time course of change in middle cerebral artery velocity (MCAv) following repeated stroke at rest and during exercise remains unknown. In this case study, we provide novel characterization of the dynamic kinetic MCAv response profile to moderate-intensity exercise before and after repeated ischemic MCA stroke. The initial stroke occurred in the left MCA. At 3 months poststroke, left MCAv amplitude (Amp) was~50% lower than the right. At the 6-month follow-up visit, MCAv Amp declined in both MCA with the left MCAv Amp 50% lower than the right MCAv Amp. Following a second right MCA stroke, we report further decline in Amp for the left MCA. At the 3-and 6-month visit following the second stroke, the left MCAv Amp declined further (~10%). The right MCAv Amp dramatically decreased by 81.3% when compared to the initial study visit. The MCAv kinetic analysis revealed a marked impairment in the cerebrovascular response to exercise following stroke. We discuss potential pathophysiological mechanisms contributing to poststroke cerebrovascular dysfunction and the need to test therapeutic interventions (such as exercise) that might attenuate cerebrovascular decline in people following stroke.

Background and Purpose Chronic hyperglycemia contributes to cerebrovascular dysfunction by damaging blood vessels. Poor glucose control has been tied to impairments in cerebral blood flow, which may be particularly detrimental for people recovering from major cerebrovascular events such as acute ischemic stroke. In this secondary analysis, we explore for the first time the connection between chronic hyperglycemia before acute stroke and the cerebrovascular response (CVR) to exercise 3 and 6 month into the subacute recovery period. Methods We recorded middle cerebral artery velocity (MCAv) using transcranial Doppler ultrasound bilaterally at rest and during moderate‐intensity exercise in stroke patients at 3 (n = 19) and 6 (n = 12) months post‐stroke. We calculated CVR as the difference between MCAv during steady‐state exercise and resting MCAv. We obtained hemoglobin A1c levels (HbA1c; a measure of blood glucose over the prior 3 months) from the electronic medical record (EMR) and divided participants by HbA1c greater or less than 7%. Results Participants with high HbA1c (>7%) at the time of acute stroke had significantly lower CVR to exercise for both the stroke‐affected (p = .009) and non‐affected (p = .007) hemispheres at 3 months post‐stroke. These differences remained significant at 6 months post‐stroke (stroke‐affected, p = .008; non‐affected, p = .016). Conclusions Patients with chronic hyperglycemia before acute ischemic stroke demonstrated impaired cerebrovascular function during exercise months into the subacute recovery period. These findings highlight the importance of maintaining tight glucose control to reduce morbidity and improve recovery post‐stroke and could have implications for understanding cerebrovascular pathophysiology.

Background and Purpose: The primary aim was to characterize the middle cerebral artery blood velocity (MCAv) dynamic response to an acute bout of exercise at 3- and 6-months post stroke. As a secondary objective, we grouped individuals according to the MCAv dynamic response to the exercise bout as responder or non-responder. We tested whether physical activity, aerobic fitness and exercise mean arterial blood pressure (MAP) differed between groups. Methods: Transcranial Doppler ultrasound measured MCAv during a 90-second baseline (BL) followed by a 6-minute moderate intensity exercise bout. Heart rate (HR), MAP and end tidal CO2 (PETCO2) were additional variables of interest. The MCAv dynamic response variables included: BL, time delay (TD), amplitude and time constant (τ). Results: Individuals enrolled in the study at 3 months post-stroke and the follow up visit commenced at 6 months post-stroke. Linear mixed model revealed no significant differences in our selected outcomes across between 3- and 6-months post-stroke. Individuals characterized as responders demonstrated a faster TD, higher amplitude, reported higher levels of physical activity and aerobic fitness when compared to the non-responders. No between group differences were identified for BL, τ or exercise MAP. In the non-responders, we observed an immediate rise in MCAv following exercise onset followed by an immediate decline to near BL values while the responders showed an exponential rise until steady state was reached. Conclusions: The MCAv dynamic response profile has the potential to provide valuable information during an acute exercise bout following stroke. Individuals with a greater MCAv response to the exercise stimulus reported regular participation in exercise than those who reported being sedentary.

Introduction:Quality improvement (QI) is an imperative aspect of healthcare and resident education, and as such, an emphasis has been placed on the development of QI curricula. We set out to describe and analyze the effectiveness of the PSQI Curriculum within the PM&R Residency Program at the University of Kansas Medical Center during the academic years of 2017-2020. Methods:The curriculum includes nine mandatory institute for healthcare improvement modules, the university's GME core conference series, the departments patient safety conference series, a PSQI lecture series, and annual resident-led QI projects. Resident PSQI knowledge was assessed before and after completion of the annual curriculum through an internally generated questionnaire with optional resident feedback. Results:A total of 16 PM&R residents participated in this curriculum for a minimum of one or more years during the academic years of 2017-2020. We found a significant difference in 9 of 12 domains during the 2017-2018 academic year, 10 of 12 domains during the 2018-2019 academic year, and 10 of 12 domains during the 2019-2020 academic year. Aggregating for all academic years revealed a statistically significant difference across all 12 domains. Discussion:In order to graduate from an ACGME-accredited residency program, residents must exhibit proficiency in PBLI and SBP, which includes the domain of quality improvement. The continuous QI curriculum within the PM&R Residency Program at KUMC has proven to be effective in improving residents' familiarity and comfort with quality assessment and improvement and may serve as a model for other PM&R programs around the nation.

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