scholarly journals Pilot Study to Characterize Middle Cerebral Artery Dynamic Response to an Acute Bout of Moderate Intensity Exercise at 3‐ and 6‐Months Poststroke

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Sandra A. Billinger ◽  
Alicen A. Whitaker ◽  
Allegra Morton ◽  
Carolyn S. Kaufman ◽  
Sophy J. Perdomo ◽  
...  

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.

2020 ◽  
Author(s):  
Sandra A Billinger ◽  
Alicen A Whitaker ◽  
Allegra Morton ◽  
Carolyn S Kaufman ◽  
Sophy J Perdomo ◽  
...  

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.


2007 ◽  
Vol 34 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Sanjay Subramanian ◽  
Murat Yilmaz ◽  
Ahmer Rehman ◽  
Rolf D. Hubmayr ◽  
Bekele Afessa ◽  
...  

2000 ◽  
Vol 92 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Helene Benveniste ◽  
Katie R. Kim ◽  
Laurence W. Hedlund ◽  
John W. Kim ◽  
Allan H. Friedman

Object. It is taken for granted that patients with hypertension are at greater risk for intracerebral hemorrhage during neurosurgical procedures than patients with normal blood pressure. The anesthesiologist, therefore, maintains mean arterial blood pressure (MABP) near the lower end of the autoregulation curve, which in patients with preexisting hypertension can be as high as 110 to 130 mm Hg. Whether patients with long-standing hypertension experience more hemorrhage than normotensive patients after brain surgery if their blood pressure is maintained at the presurgical hypertensive level is currently unknown. The authors tested this hypothesis experimentally in a rodent model.Methods. Hemorrhage and edema in the brain after needle biopsy was measured in vivo by using three-dimensional magnetic resonance (MR) microscopy in the following groups: WKY rats, acutely hypertensive WKY rats, spontaneously hypertensive rats (SHR strain), and SHR rats treated with either sodium nitroprusside or nicardipine. Group differences were compared using Tukey's studentized range test followed by individual pairwise comparisons of groups and adjusted for multiple comparisons.There were no differences in PaCO2, pH, and body temperature among the groups. The findings in this study indicated that only acutely hypertensive WKY rats had larger volumes of hemorrhage. Chronically hypertensive SHR rats with MABPs of 130 mm Hg did not have larger hemorrhages than normotensive rats. There were no differences in edema volumes among groups.Conclusions. The brains of SHR rats with elevated systemic MABPs are probably protected against excessive hemorrhage during surgery because of greater resistance in the larger cerebral arteries and, thus, reduced cerebral intravascular pressures.


PEDIATRICS ◽  
1992 ◽  
Vol 89 (4) ◽  
pp. 643-647 ◽  
Author(s):  
Lena Hellström-Westas ◽  
Nils W. Svenningsen ◽  
Angela H. Bell ◽  
Liselotte Skov ◽  
Gorm Greisen

During surfactant treatment of respiratory distress syndrome, 23 premature newborns were investigated with continuous amplitude-integrated electroencephalography (cerebral function monitors). Simultaneously, arterial blood pressure and transcutaneous blood gas values were recorded. A short(<10 minutes) but significant decrease in cerebral activity was seen in almost all neonates immediately after the surfactant instillation, in spite of an improved pulmonary function. In 21 of 23 neonates, a transient fall in mean arterial blood pressure of 9.3 mm Hg (mean) occurred coincidently with the cerebral reaction. Neonates in whom intraventricular hemorrhage developed tended to have lower presurfactant mean arterial blood pressure (P> .05), but they had a significantly lower mean arterial blood pressure after surfactant instillation (P < .05). No other differences were found between neonates in whom intraventricular hemorrhage developed and those without intraventricular hemorrhage. The present findings demonstrate that an acute cerebral dysfunction may occur after surfactant instillation. In some vulnerable neonates with arterial hypotension and severe pulmonary immaturity,the fall in mean arterial blood pressure may increase the risk of cerebral complications and could be related to an unchanged rate of intraventricular hemorrhage after surfactant treatment.


1996 ◽  
Vol 30 (6) ◽  
pp. 578-582 ◽  
Author(s):  
Neal R Cutler ◽  
John J Sramek ◽  
Azucena Luna ◽  
Ismael Mena ◽  
Eric P Brass ◽  
...  

Objective To assess the effect of the angiotensin-converting enzyme inhibitor ceronapril on cerebral blood flow (CBF) in patients with moderate hypertension. Design Patients received chlorthalidone 25 mg for 4 weeks, and if diastolic blood pressure remained in the range of 100–115 mm Hg, they were given titrated doses of ceronapril (10–40 mg/d based on blood pressure response) in addition to chlorthalidone for 9 weeks. Setting Outpatient research clinic. Subjects Eligible patients had moderate essential hypertension (diastolic blood pressure 100–115 mm Hg) assessed when the patients were receiving no medications. Thirteen patients were entered into the study; 1 withdrew for reasons unrelated to the study drug. Twelve patients (11 men, 1 woman; mean age 52 y) completed the study. Intervention Ceronapril, given with chlorthalidone. Main Outcome Measures CBF measurements were taken at the start and end of ceronapril therapy using intravenous 133Xe; blood pressures were determined weekly. Results Mean arterial blood pressure decreased from 130 ± 4 to 120 ±7 mm Hg after 4 weeks of chlorthalidone administration, and fell further to 108 ± 8 mm Hg after an additional 9 weeks of combined chlorthalidone-ceronapril therapy (p < 0.05). CBF fell from 44 ± 15 to 34 ± 5 mL/min/100 g during the 9 weeks of combined therapy (p = 0.05). No adverse effects consistent with decreased CBF were observed. The decrease in CBF was not linearly correlated with the change in systemic blood pressure, but was strongly correlated (r = –0.937; p < 0.001) with the initial CBF. Conclusions The decrease in mean arterial blood pressure was not associated with a decrease in CBF. Patients with high CBF may be predisposed to a decrease in CBF when treated with ceronapril and chlorthalidone.


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