Journal of hypertension
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Journal of hypertension · Jul 2001
Comparative StudyAmbulatory heart rate is underestimated when measured by an ambulatory blood pressure device.
To test the validity of ambulatory heart rate (HR) assessment with a cuff ambulatory blood pressure (ABP) monitor. ⋯ A direct effect of cuff inflation leads to the underestimation of ongoing HR during cuff-based ABP measurement. Additional underestimation of HR occurs during periods with physical activity, probably due to behavioural freezing during blood pressure measurements. HR underestimation was not affected by hypertensive state. When its limitations are taken into account, ABP-derived ambulatory HR can be considered a reliable and valid measure.
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Journal of hypertension · Jun 2001
Comparative StudyNon-invasive assessment of local arterial pulse pressure: comparison of applanation tonometry and echo-tracking.
Pulse pressure is not constant throughout the arterial tree. Use of pulse pressure at one arterial site as surrogate for pulse pressure at another arterial site may be erroneous. The present study compares three non-invasive techniques to measure local pulse pressure: (i) internally calibrated readings from applanation tonometry, (ii) alternative calibration of pressure waves obtained with applanation tonometry and (iii) alternative calibration of arterial distension waves obtained with echo-tracking. Alternative calibration assumes mean and diastolic blood pressure constant throughout the large artery tree. ⋯ Pulse pressure obtained from alternatively calibrated tonometer-derived pressure waves and echo-tracking-derived distension waves demonstrates good accuracy. Accuracy of pulse pressure from internally calibrated applanation tonometer readings at the carotid artery is poor.
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Journal of hypertension · Mar 2001
Differential activation of extracellular signal-regulated protein kinase 1/2 and p38 mitogen activated-protein kinase by AT1 receptors in vascular smooth muscle cells from Wistar-Kyoto rats and spontaneously hypertensive rats.
The present study investigates effects of angiotensin II on activation of extracellular signal-regulated protein kinase (ERK) 1/2, p38 mitogen activated-protein kinase (p38MAPK) and c-Jun amino terminal kinase (JNK) in vascular smooth muscle cells from spontaneously hypertensive rats (SHR). ⋯ Angiotensin II-induced activation of vascular ERK1/2 and p38MAPK is increased in SHR. These effects are mediated via AT1 receptors, which activate Src-dependent pathways. Overexpression of c-fos mRNA in SHR is due to ERK1/2-dependent, p38MAPK-independent pathways. Our results suggest that angiotensin II activates numerous MAP kinases in VSMCs and that differential activation of these kinases may be important in altered growth signaling in VSMCs from SHR.
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Journal of hypertension · May 2000
Influence of movement arousal on circadian rhythm of blood pressure in obstructive sleep apnea syndrome.
To investigate the hypothesis that repeated arousals at the termination of apnea/hypopnea in obstructive sleep apnea syndrome (OSAS) are related to abnormal circadian rhythm of blood pressure (BP). ⋯ Our findings suggest that MA and oxygen desaturation in OSAS make an important contribution to abnormal circadian rhythm of BP. We conclude that repeated end-apneic arousal and/or hypoxic asphyxia and the subsequent sleep fragmentation may contibute to nocturnal and diurnal elevation of BP.
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Journal of hypertension · Apr 2000
Comparative StudyComparison of nurse- and physician-determined clinic blood pressure levels in patients referred to a hypertension clinic: implications for subsequent management.
When measuring BP, the physician induces a transient pressor response triggered by an alarm reaction. This 'white-coat effect' can influence therapeutic decisions. Whether it depends on the characteristics of the physician has not been evaluated. ⋯ Large between-physician differences exist in the magnitude of the white-coat effect that cannot be explained by patient characteristics. Physicians should therefore not make any decisions based on blood pressure measured manually during a first encounter.