Blood Flow Pattern in the Middle Cerebral Artery in Relation to Indices of Arterial Stiffness in the Systemic Circulation

Tian, Xu; Staessen, Jan A.; Wei, Fang‐Fei; Xu, Jie; Li, Fa-Hong; Fan, Weizheng; Gao, Pingjin; Wang, Ji‐Guang; Li, Yan

doi:10.1038/ajh.2011.223

Cited by 66 publications

(77 citation statements)

References 28 publications

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“…Cerebral pulsatility index was also calculated according to the measure of Gosling, and normalized cerebral pulsatility index for systemic pulsatility index to generate pulsatility ratio; the latter of which is more directly associated with local cerebrovascular responses. 31 All the above metrics were calculated five times per second, and all averaged trials (i.e., 10 trials for the visual task, and seven for the verbal task) for each participant.…”

Section: Discussionmentioning

confidence: 99%

Regional Neurovascular Coupling and Cognitive Performance in Those with Low Blood Pressure Secondary to High-Level Spinal Cord Injury: Improved by Alpha-1 Agonist Midodrine Hydrochloride

Phillips

Warburton

Ainslie

et al. 2014

J Cereb Blood Flow Metab

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Individuals with high-level spinal cord injury (SCI) experience low blood pressure (BP) and cognitive impairments. Such dysfunction may be mediated in part by impaired neurovascular coupling (NVC) (i.e., cerebral blood flow responses to neurologic demand). Ten individuals with SCI 4T6 spinal segment, and 10 age-and sex-matched controls were assessed for beat-by-beat BP, as well as middle and posterior cerebral artery blood flow velocity (MCAv, PCAv) in response to a NVC test. Tests were repeated in SCI after 10 mg midodrine (alpha 1 -agonist). Verbal fluency was measured before and after midodrine in SCI, and in the control group as an index of cognitive function. At rest, mean BP was lower in SCI (70 ± 10 versus 92 ± 14 mm Hg; Po0.05); however, PCAv conductance was higher (0.56 ± 0.13 versus 0.39 ± 0.15 cm/second/mm Hg; Po0.05). Controls exhibited a 20% increase in PCAv during cognition; however, the response in SCI was completely absent (Po0.01). When BP was increased with midodrine, NVC was improved 70% in SCI, which was reflected by a 13% improved cognitive function (Po0.05). Improvements in BP were related to improved cognitive function in those with SCI (r 2 ¼ 0.52; Po0.05). Impaired NVC, secondary to low BP, may partially mediate reduced cognitive function in individuals with high-level SCI. INTRODUCTIONSpinal cord injury (SCI) is a devastating condition often resulting in disturbed motor, sensory, and autonomic function. As a result of disrupted descending autonomic spinal pathways after SCI, sympathetic vasomotor tone is impaired, often resulting in arterial hypotension. 1 Those with injury at or above T 6 spinal segment, because of a myriad of potential mechanisms (including decentralization of sympathetically mediated vasomotor tone in the splanchnic region and legs) have more profound autonomic disturbances including resting hypotension and orthostatic hypotension as compared with those with lower level SCI. 2 An abundance of evidence, from both animal and human studies, demonstrated that there is an association between low blood pressure (BP) and a variety of cognitive impairments. 3,4 There is well-established evidence that individuals with SCI have a high rate of traumatic brain injury that can result in a significant number of cognitive dysfunctions. 5 However, the high prevalence of cognitive dysfunction (i.e., between 10% and 60%) in SCI 6,7 is likely to be at least partially due to widespread hypotension. 8 This notion is further highlighted by a significant positive relationship between systolic BP (SBP) and cognitive function in the SCI population. 9

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Section: Discussionmentioning

confidence: 99%

Regional Neurovascular Coupling and Cognitive Performance in Those with Low Blood Pressure Secondary to High-Level Spinal Cord Injury: Improved by Alpha-1 Agonist Midodrine Hydrochloride

Phillips

Warburton

Ainslie

et al. 2014

J Cereb Blood Flow Metab

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“…As described elsewhere, 11,12 we recruited consecutive patients referred for ambulatory blood pressure monitoring to the Hypertension Outpatient Clinic of Ruijin Hospital, Shanghai, China. We adhered to the principles of the Declaration of Helsinki, and the study protocol was approved by the Ethics Committee of Ruijin Hospital, Shanghai Jiaotong University School of Medicine.…”

Section: Study Populationmentioning

confidence: 99%

Association of Target Organ Damage With 24-Hour Systolic and Diastolic Blood Pressure Levels and Hypertension Subtypes in Untreated Chinese

Wei

Zhang

et al. 2014

Hypertension

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Abstract-The association of target organ damage with 24-hour systolic and diastolic blood pressure levels and ambulatory hypertension subtypes has not yet been examined in untreated Chinese patients. We measured left ventricular mass index by echocardiography (n=619), the urinary albumin:creatinine ratio (n=1047), and aortic pulse wave velocity by tonometry (n=1013) in 1047 untreated subjects (mean age, 50.6 years; 48.9% women). Normotension was a 24-hour systolic/diastolic blood pressure <130/<80 mm Hg. Hypertension subtypes were isolated diastolic hypertension and mixed systolic plus diastolic hypertension. We assessed associations of interest by multivariable-adjusted linear models. Using normotension as reference, mixed hypertension was associated with higher (P≤0.003) left ventricular mass index (+4.31 g/m 2 ), urinary albumin:creatinine ratio (+1.63 mg/mmol), and pulse wave velocity (+0.76 m/s); and isolated diastolic hypertension was associated with similar left ventricular mass index and pulse wave velocity (P≥0.39), but higher urinary albumin:creatinine ratio (+1.24 mg/mmol; P=0.002). In younger participants (<55 years), the mutually independent effect sizes associated with 1 SD increases in 24-hour systolic/diastolic blood pressure were +3.31/-0.36 g/m 2 (P=0.009/0.79) for left ventricular mass index, +1.15/+1.14 mg/mmol (P=0.02/0.04) for the urinary albumin:creatinine ratio, and +0.54/-0.05 m/s (P<0.001/0.54) for pulse wave velocity. In older participants, these estimates were +3.58/+0.30 g/m 2 (P=0.045/0.88), +1.23/+1.05 mg/mmol (P=0.002/0.54), and +0.76/-0.49 m/s (P<0.001/<0.001), respectively. In conclusion, 24-hour systolic blood pressure and mixed hypertension are major determinants of target organ damage irrespective of age and target organ, whereas 24-hour diastolic blood pressure and isolated diastolic hypertension only relate to the urinary albumin:creatinine ratio below middle

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“…However, no study has to date evaluated the association between flow pulsatility and cause of stroke, or the association between pressure/flow pulsatility and arterial stiffness in patients after symptomatic ischemic stroke. Recently, increased aortic stiffness has been shown to be related to flow pulsatility in patients without a history of stroke [12,13]. To date, no study has compared the relative contribution of cerebrovascular resistance (CVR) and aortic stiffness to pressure/flow pulsatility in the common carotid artery (CCA) after ischemic stroke.…”

Section: Introductionmentioning

confidence: 99%

Large artery stiffness and carotid flow pulsatility in stroke survivors

Wohlfahrt

Krajčoviechová

Jozífová

et al. 2014

Journal of Hypertension

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Blood Flow Pattern in the Middle Cerebral Artery in Relation to Indices of Arterial Stiffness in the Systemic Circulation

Abstract: MCA blood flow is closely associated with the pulsatile pressure in the systemic circulation, which depends on arterial stiffness as measured by PWV.

Cited by 66 publications

References 28 publications

Regional Neurovascular Coupling and Cognitive Performance in Those with Low Blood Pressure Secondary to High-Level Spinal Cord Injury: Improved by Alpha-1 Agonist Midodrine Hydrochloride

Regional Neurovascular Coupling and Cognitive Performance in Those with Low Blood Pressure Secondary to High-Level Spinal Cord Injury: Improved by Alpha-1 Agonist Midodrine Hydrochloride

Association of Target Organ Damage With 24-Hour Systolic and Diastolic Blood Pressure Levels and Hypertension Subtypes in Untreated Chinese

Large artery stiffness and carotid flow pulsatility in stroke survivors

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