Browsing by Author "Sverrisdottir, Yrsa"

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High-Intensity Interval Training Decreases Muscle Sympathetic Nerve Activity in Men With Essential Hypertension and in Normotensive Controls
(2020) Sverrisdottir, Yrsa
Abstract: Exercise training is a cornerstone in reducing blood pressure (BP) and muscle sympathetic nerve activity (MSNA) in individuals with essential hypertension. Highintensity interval training (HIIT) has been shown to be a time efficient alternative to classical continuous training in lowering BP in essential hypertension, but the effect of HIIT on MSNA levels has never been investigated. Leg MSNA responsiveness to 6 weeks of HIIT was examined in 14 hypertensive men (HYP; age: 62 _ 7 years, night time BP: 136 _ 12/83 _ 8 mmHg, BMI: 28 _ 3 kg/m2), and 10 age-matched normotensive controls (NORM; age: 60 _ 8 years, night time BP: 116 _ 2/68 _ 4 mmHg and BMI: 27 _ 3 kg/m2). Before training, MSNA levels were not different between HYP and NORM (burst frequency (BF): 41.0 _ 10.3 vs. 33.6 _ 10.6 bursts/min and burst incidence (BI): 67.5 _ 19.7 vs. 64.2 _ 17.0 bursts/100 heart beats, respectively). BF decreased (P < 0.05) with training by 13 and 5% in HYP and NORM, respectively, whereas BI decreased by 7% in NORM only, with no difference between groups. Training lowered (P < 0.05) night-time mean arterial- and diastolic BP in HYP only (100 _ 8 vs. 97 _ 5, and 82 _ 6 vs. 79 _ 5 mmHg, respectively). The change in HYP was greater (P < 0.05) compared to NORM. Training reduced (P < 0.05) body mass, visceral fat mass, and fat percentage similarly within- and between groups, with no change in fat free mass. Training increased (P < 0.05) V˙ O2-max in NORM only. Six weeks of HIIT lowered resting MSNA levels in age-matched hyper- and normotensive men, which was paralleled by a significant reduction in BP in the hypertensive men
A single-centre investigator-blinded randomised parallel-group study protocol to investigate the influence of an acclimatisation appointment on children’s behaviour during N2O/O2 sedation as measured by psychological, behavioural and real-time physiological parameters
(2020) Kowash, Mawlood; Al Halabi, Manal; Hussein, Iyad; Abdo, Mohammad M; Salami, Anas; Hassan Khamis, Amar; Sverrisdottir, Yrsa
Aims and objectives: To describe a study protocol of a randomised control trial (RCT) assessing the effectiveness, in reducing dental anxiety, of an acclimatising nitrous oxide sedation (N2O) session prior to actual dental treatment with N2O. Materials and methods: A single-centre investigator-blinded parallel-group RCT conducted in a postgraduate dental hospital in Dubai, United Arab Emirates (UAE). Anxious children requiring N2O (aged 5–15 years) will be randomly assigned to; a study group: children who will have a preparatory N2O trial experience or; a control group: children who will only have N2O explained to them. Treatment with N2O for both groups will start at the second visit. The following outcomes will be recorded: completion of dental treatment, anxiety scores at baseline and after treatment (using the Modified Child Dental Anxiety Scale faces), behaviour of the child (using Frankl Rating Behaviour Scale) and the acquisition of real-time physiological anxiety-related parameters (using E4® electronic wrist devices). Results: The data will be analysed statistically. Discussion: There is a paucity of research regarding dental N2O acclimatising appointments. This RCT will supplement existing literature. Conclusions: This RCT will report whether prior acclimatising of a child to N2O sedation is effective, or not, in improving dental treatment behaviour.
Variations in Cardiovascular Structure, Function, and Geometry in Midlife Associated With a History of Hypertensive Pregnancy
(2020) Sverrisdottir, Yrsa
Abstract: Hypertensive pregnancy is associated with increased maternal cardiovascular risk in later life. A range of cardiovascular adaptations after pregnancy have been reported to partly explain this risk. We used multimodality imaging to identify whether, by midlife, any pregnancy-associated phenotypes were still identifiable and to what extent they could be explained by blood pressure. Participants were identified by review of hospital maternity records 5 to 10 years after pregnancy and invited to a single visit for detailed cardiovascular imaging phenotyping. One hundred seventy-three women (age, 42±5 years, 70 after normotensive and 103 after hypertensive pregnancy) underwent magnetic resonance imaging of the heart and aorta, echocardiography, and vascular assessment, including capillaroscopy. Women with a history of hypertensive pregnancy had a distinct cardiac geometry with higher left ventricular mass index (49.9±7.1 versus 46.0±6.5 g/m2; P=0.001) and ejection fraction (65.6±5.4% versus 63.7±4.3%; P=0.03) but lower global longitudinal strain (−18.31±4.46% versus −19.94±3.59%; P=0.02). Left atrial volume index was also increased (40.4±9.2 versus 37.3±7.3 mL/m2; P=0.03) and E:A reduced (1.34±0.35 versus 1.52±0.45; P=0.003). Aortic compliance (0.240±0.053 versus 0.258±0.063; P=0.046) and functional capillary density (105.4±23.0 versus 115.2±20.9 capillaries/mm2; P=0.01) were reduced. Only differences in functional capillary density, left ventricular mass, and atrial volume indices remained after adjustment for blood pressure (P<0.01, P=0.01, and P=0.04, respectively). Differences in cardiac structure and geometry, as well as microvascular rarefaction, are evident in midlife after a hypertensive pregnancy, independent of blood pressure. To what extent these phenotypic patterns contribute to cardiovascular disease progression or provide additional measures to improve risk stratification requires further study.