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1.
Pediatr Res ; 94(1): 313-320, 2023 07.
Article in English | MEDLINE | ID: mdl-36624285

ABSTRACT

BACKGROUND: Maternal obesity during pregnancy is associated with poorer cardiovascular health (CVH) in children. A strategy to improve CVH in children could be to address preconception maternal obesity by means of a lifestyle intervention. We determined if a preconception lifestyle intervention in women with obesity improved offspring's CVH, assessed by magnetic resonance imaging (MRI). METHODS: We invited children born to women who participated in a randomised controlled trial assessing the effect of a preconception lifestyle intervention in women with obesity. We assessed cardiac structure, function and geometric shape, pulse wave velocity and abdominal fat tissue by MRI. RESULTS: We included 49 of 243 (20.2%) eligible children, 24 girls (49%) girls, mean age 7.1 (0.8) years. Left ventricular ejection fraction was higher in children in the intervention group as compared to children in the control group (63.0% SD 6.18 vs. 58.8% SD 5.77, p = 0.02). Shape analysis showed that intervention was associated with less regional thickening of the interventricular septum and less sphericity. There were no differences in the other outcomes of interest. CONCLUSION: A preconception lifestyle intervention in women with obesity led to a higher ejection fraction and an altered cardiac shape in their offspring, which might suggest a better CVH. IMPACT: A preconception lifestyle intervention in women with obesity results in a higher ejection fraction and an altered cardiac shape that may signify better cardiovascular health (CVH) in their children. This is the first experimental human evidence suggesting an effect of a preconception lifestyle intervention in women with obesity on MRI-derived indicators of CVH in their children. Improving maternal preconception health might prevent some of the detrimental consequences of maternal obesity on CVH in their children.


Subject(s)
Obesity, Maternal , Humans , Female , Pregnancy , Child , Male , Obesity, Maternal/complications , Pulse Wave Analysis , Stroke Volume , Preconception Care/methods , Ventricular Function, Left , Obesity/complications , Obesity/therapy , Life Style
2.
J Invasive Cardiol ; 34(12): E879-E882, 2022 12.
Article in English | MEDLINE | ID: mdl-36328517

ABSTRACT

Application of the hybrid algorithm for the treatment of coronary chronic total occlusions requires the operator to readily deploy complex techniques and advanced technologies to achieve successful revascularization. Patient-specific factors and limitations in torquability and material strength of low-profile equipment such as microcatheters can result in procedural complications due to device fracture. Using a mini-series of 2 cases to demonstrate the successful application of antegrade dissection re-entry techniques to overcome such challenges, we highlight procedural complexities and risk, and review prior approaches and literature.


Subject(s)
Coronary Occlusion , Percutaneous Coronary Intervention , Humans , Coronary Occlusion/diagnosis , Coronary Occlusion/surgery , Percutaneous Coronary Intervention/adverse effects
4.
Eur Heart J Cardiovasc Imaging ; 23(12): 1645-1653, 2022 11 17.
Article in English | MEDLINE | ID: mdl-34931224

ABSTRACT

AIMS: Statistical shape models (SSMs) of cardiac anatomy provide a new approach for analysis of cardiac anatomy. In adults, specific cardiac morphologies associate with cardiovascular risk factors and early disease stages. However, the relationships between morphology and risk factors in children remain unknown. We propose an SSM of the paediatric left ventricle to describe its morphological variability, examine its relationship with biometric parameters and identify adverse anatomical remodelling associated with obesity. METHODS AND RESULTS: This cohort includes 2631 children (age 10.2 ± 0.6 years), mostly Western European (68.3%) with a balanced sex distribution (51.3% girls) from Generation R study. Cardiac magnetic resonance short-axis cine scans were segmented. Three-dimensional left ventricular (LV) meshes are automatically fitted to the segmentations to reconstruct the anatomies. We analyse the relationships between the LV anatomical features and participants' body surface area (BSA), age, and sex, and search for features uniquely related to obesity based on body mass index (BMI). In the SSM, 19 modes described over 90% of the population's LV shape variability. Main modes of variation were related to cardiac size, sphericity, and apical tilting. BSA, age, and sex were mostly correlated with modes describing LV size and sphericity. The modes correlated uniquely with BMI suggested that obese children present with septo-lateral tilting (R2 = 4.0%), compression in the antero-posterior direction (R2 = 3.3%), and decreased eccentricity (R2 = 2.0%). CONCLUSIONS: We describe the variability of the paediatric heart morphology and identify anatomical features related to childhood obesity that could aid in risk stratification. Web service is released to provide access to the new shape parameters.


Subject(s)
Magnetic Resonance Imaging, Cine , Pediatric Obesity , Adult , Female , Child , Humans , Male , Magnetic Resonance Imaging, Cine/methods , Ventricular Function, Left , Pediatric Obesity/diagnostic imaging , Pediatric Obesity/complications , Pediatric Obesity/pathology , Heart Ventricles/pathology , Heart
5.
JAMA Cardiol ; 6(7): 821-829, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33978675

ABSTRACT

Importance: Preterm-born individuals have higher blood pressure with an increased risk of hypertension by young adulthood, as well as potentially adverse cardiac remodeling even when normotensive. To what extent blood pressure elevation affects left ventricular (LV) structure and function in adults born preterm is currently unknown. Objective: To investigate whether changes observed in LV structure and function in preterm-born adults make them more susceptible to cardiac remodeling in association with blood pressure elevation. Design, Setting, and Participants: This cross-sectional cohort study, conducted at the Oxford Cardiovascular Clinical Research Facility and Oxford Centre for Clinical Magnetic Resonance Research, included 468 adults aged 18 to 40 years. Of these, 200 were born preterm (<37 weeks' gestation) and 268 were born at term (≥37 weeks' gestation). Cardiac magnetic resonance imaging was used to characterize LV structure and function, with clinical blood pressure readings measured to assess hypertension status. Demographic and anthropometric data, as well as birth history and family medical history information, were collected. Data were analyzed between January 2012 and February 2021. Main Outcomes and Measures: Cardiac magnetic resonance measures of LV structure and function in response to systolic blood pressure elevation. Results: The cohort was primarily White (>95%) with a balanced sex distribution (51.5% women and 48.5% men). Preterm-born adults with and without hypertension had higher LV mass index, reduced LV function, and smaller LV volumes compared with term-born individuals both with and without hypertension. In regression analyses of systolic blood pressure with LV mass index and LV mass to end-diastolic volume ratio, there was a leftward shift in the slopes in preterm-born compared with term-born adults. Compared with term-born adults, there was a 2.5-fold greater LV mass index per 1-mm Hg elevation in systolic blood pressure in very and extremely preterm-born adults (<32 weeks' gestation) (0.394 g/m2 vs 0.157 g/m2 per 1 mm Hg; P < .001) and a 1.6-fold greater LV mass index per 1-mm Hg elevation in systolic blood pressure in moderately preterm-born adults (32 to 36 weeks' gestation) (0.250 g/m2 vs 0.157 g/m2 per 1 mm Hg; P < .001). The LV mass to end-diastolic volume ratio per 1-mm Hg elevation in systolic blood pressure in the very and extremely preterm-born adults was 3.4-fold greater compared with those born moderately preterm (3.56 × 10-3 vs 1.04 × 10-3 g/mL per 1 mm Hg; P < .001) and 3.3-fold greater compared with those born at term (3.56 × 10-3 vs 1.08 × 10-3 g/mL per 1 mm Hg; P < .001). Conclusions and Relevance: Preterm-born adults have a unique LV structure and function that worsens with systolic blood pressure elevation. Additional primary prevention strategies specifically targeting cardiovascular risk reduction in this population may be warranted.


Subject(s)
Hypertension/etiology , Premature Birth , Ventricular Remodeling , Adult , Cross-Sectional Studies , Female , Heart/diagnostic imaging , Humans , Infant, Extremely Premature , Magnetic Resonance Imaging , Male , Risk Factors
6.
PLoS Comput Biol ; 17(4): e1008851, 2021 04.
Article in English | MEDLINE | ID: mdl-33857152

ABSTRACT

Cardiac anatomy plays a crucial role in determining cardiac function. However, there is a poor understanding of how specific and localised anatomical changes affect different cardiac functional outputs. In this work, we test the hypothesis that in a statistical shape model (SSM), the modes that are most relevant for describing anatomy are also most important for determining the output of cardiac electromechanics simulations. We made patient-specific four-chamber heart meshes (n = 20) from cardiac CT images in asymptomatic subjects and created a SSM from 19 cases. Nine modes captured 90% of the anatomical variation in the SSM. Functional simulation outputs correlated best with modes 2, 3 and 9 on average (R = 0.49 ± 0.17, 0.37 ± 0.23 and 0.34 ± 0.17 respectively). We performed a global sensitivity analysis to identify the different modes responsible for different simulated electrical and mechanical measures of cardiac function. Modes 2 and 9 were the most important for determining simulated left ventricular mechanics and pressure-derived phenotypes. Mode 2 explained 28.56 ± 16.48% and 25.5 ± 20.85, and mode 9 explained 12.1 ± 8.74% and 13.54 ± 16.91% of the variances of mechanics and pressure-derived phenotypes, respectively. Electrophysiological biomarkers were explained by the interaction of 3 ± 1 modes. In the healthy adult human heart, shape modes that explain large portions of anatomical variance do not explain equivalent levels of electromechanical functional variation. As a result, in cardiac models, representing patient anatomy using a limited number of modes of anatomical variation can cause a loss in accuracy of simulated electromechanical function.


Subject(s)
Heart/physiology , Models, Cardiovascular , Adult , Healthy Volunteers , Heart/anatomy & histology , Humans , Tomography, X-Ray Computed
7.
J Hypertens ; 39(7): 1421-1428, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33534345

ABSTRACT

BACKGROUND: Basal septal hypertrophy (BSH) is an asymmetric, localized thickening of the upper interventricular septum and constitutes a marker of an early remodelling in patients with hypertension. This morphological trait has been extensively researched because of its prevalence in hypertension, yet its clinical and prognostic value for individual patients remains undetermined. One of the reasons is the lack of a reliable and reproducible metric to quantify the presence and the extent of BSH. This article proposes the use of the curvature of the left ventricular endocardium as a robust feature for BSH characterization, and as an objective criterion to quantify current subjective 'visual assessment' of the presence of sigmoidal septum. The proposed marker, called average septal curvature, is defined as the inverse of the radius adjacent to each point of the endocardial contour along the basal and mid inferoseptal segments of the left ventricle. METHOD: Robustness and reproducibility were assessed on a cohort of 220 patients, including 161 hypertensive patients (32 with BSH) and 59 healthy controls. RESULTS: The results show that compared with the conventionally used wall thickness metrics, the new marker is more reproducible (relative standard deviation of errors of 7 vs. 13%, and 8 vs. 38% for intra-observer and inter-observer variability, respectively) and better correlates to the functional parameters related to BSH, with main difference (absolute rank correlation 0.417 vs. 0.341) in local deformation changes assessed by longitudinal strain. CONCLUSION: Average septal curvature is a more precisely defined and reproducible metric than thickness ratios, it can be fully automated, and better infers the functional remodelling related to hypertension.


Subject(s)
Hypertension , Cohort Studies , Heart Ventricles , Humans , Hypertrophy , Reproducibility of Results
8.
IEEE Trans Med Imaging ; 40(10): 2783-2794, 2021 10.
Article in English | MEDLINE | ID: mdl-33444134

ABSTRACT

Deep learning can bring time savings and increased reproducibility to medical image analysis. However, acquiring training data is challenging due to the time-intensive nature of labeling and high inter-observer variability in annotations. Rather than labeling images, in this work we propose an alternative pipeline where images are generated from existing high-quality annotations using generative adversarial networks (GANs). Annotations are derived automatically from previously built anatomical models and are transformed into realistic synthetic ultrasound images with paired labels using a CycleGAN. We demonstrate the pipeline by generating synthetic 2D echocardiography images to compare with existing deep learning ultrasound segmentation datasets. A convolutional neural network is trained to segment the left ventricle and left atrium using only synthetic images. Networks trained with synthetic images were extensively tested on four different unseen datasets of real images with median Dice scores of 91, 90, 88, and 87 for left ventricle segmentation. These results match or are better than inter-observer results measured on real ultrasound datasets and are comparable to a network trained on a separate set of real images. Results demonstrate the images produced can effectively be used in place of real data for training. The proposed pipeline opens the door for automatic generation of training data for many tasks in medical imaging as the same process can be applied to other segmentation or landmark detection tasks in any modality. The source code and anatomical models are available to other researchers.1 1https://adgilbert.github.io/data-generation/.


Subject(s)
Image Processing, Computer-Assisted , Neural Networks, Computer , Echocardiography , Humans , Reproducibility of Results , Ultrasonography
9.
Int J Cardiovasc Imaging ; 37(1): 145-154, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32789553

ABSTRACT

A index of non-invasive myocardial work (MWI) can account for pressure during the assessment of cardiac function, potentially separating the influence of loading conditions from the influence of the underlying tissue remodelling. The aim is to assess LV function accounted for loading and explore hypertensive MWI distribution by comparing healthy individuals to hypertensive patients without and with localized basal septal hypertrophy (BSH). An echocardiogram was performed in 170 hypertensive patients and 20 healthy individuals. BSH was defined by a basal-to-mid septal wall thickness ratio ≥ 1.4. LV speckle-tracking was performed, and the MWI calculated globally and regionally for the apical, mid and basal regions. An apex-to-base gradient, seen in regional strain values, was preserved in the distribution of myocardial work, with the apical region compensating for the impairment of the basal segments. This functional redistribution was further pronounced in patients with localized BSH. In these patients, segmental MWI analysis revealed underlying impairment of regional work unrelated to acute loading conditions. Non-invasive MWI analysis offers the possibility to compare LV function regardless of blood pressure at the time of observation. Changes in MWI distribution can be seen in hypertension unrelated to the load-dependency of strain. Accentuated functional changes affirm the role of BSH as an echocardiographic marker in hypertension.


Subject(s)
Arterial Pressure , Echocardiography , Hypertension/complications , Hypertrophy, Left Ventricular/diagnostic imaging , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Function, Left , Ventricular Pressure , Case-Control Studies , Europe , Female , Humans , Hypertension/diagnosis , Hypertension/physiopathology , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/physiopathology , Male , Middle Aged , Predictive Value of Tests , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Remodeling
10.
Eur Heart J ; 41(48): 4556-4564, 2020 12 21.
Article in English | MEDLINE | ID: mdl-32128588

ABSTRACT

Providing therapies tailored to each patient is the vision of precision medicine, enabled by the increasing ability to capture extensive data about individual patients. In this position paper, we argue that the second enabling pillar towards this vision is the increasing power of computers and algorithms to learn, reason, and build the 'digital twin' of a patient. Computational models are boosting the capacity to draw diagnosis and prognosis, and future treatments will be tailored not only to current health status and data, but also to an accurate projection of the pathways to restore health by model predictions. The early steps of the digital twin in the area of cardiovascular medicine are reviewed in this article, together with a discussion of the challenges and opportunities ahead. We emphasize the synergies between mechanistic and statistical models in accelerating cardiovascular research and enabling the vision of precision medicine.


Subject(s)
Artificial Intelligence , Cardiology , Algorithms , Humans , Precision Medicine
11.
Am J Cardiol ; 125(9): 1339-1346, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32164912

ABSTRACT

Basal septal hypertrophy (BSH) is commonly seen in patients with systemic hypertension and has been associated with increased afterload. The impact of localized hypertrophy on left ventricular (LV) and left atrial (LA) function is still unclear. Our aim is to investigate if BSH is a marker of a more pronounced impact of hypertension on cardiac function in the early stages of hypertensive heart disease. An echocardiogram was performed in 163 well-controlled hypertensive patients and 22 healthy individuals. BSH was defined by a basal-to-mid septal thickness ratio ≥1.4. LV dimensions and mass were evaluated. LV global and regional deformation was assessed by 2-dimensional (2D) speckle tracking echocardiography, and LV diastolic function by 2D and Doppler imaging. LA function was evaluated with phasic volume indices calculated from 2D and 3-dimensional volumes, as well as speckle tracking echocardiography. The population was 54% men, mean age 57 (53 to 60) years. BSH was seen in 20% (n = 32) of the hypertensive cohort. Patients with BSH showed decreased regional LV systolic deformation, impaired LV relaxation with a higher proportion of indeterminate LV diastolic function, and LA functional impairment defined by a reduction of reservoir strain and a change in LA functional dynamics. In conclusion, in well-controlled hypertension impairment of LV and LA function is present in patients with early LV remodeling and localized hypertrophy. BSH might be useful as an early marker of the burden of hypertensive heart disease.


Subject(s)
Cardiomegaly/etiology , Hypertension/complications , Ventricular Septum/pathology , Atrial Function, Left , Cardiomegaly/diagnostic imaging , Cardiomegaly/physiopathology , Cohort Studies , Echocardiography , Female , Humans , Hypertension/physiopathology , Male , Middle Aged , Ventricular Function, Left , Ventricular Septum/diagnostic imaging , Ventricular Septum/physiopathology
12.
Heart Lung Circ ; 26(8): e37-e40, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28291665

ABSTRACT

Cardiogenic shock in the context of acute ST-elevation myocardial infarction (STEMI) remains a challenge to manage and results in significant mortality and morbidity, cardiac arrest in this setting even more so. The increase in myocardial oxygen demand and consumption with the use of inotropes is recognised as increasing mortality. Alternatives include the intra-aortic balloon pump (IABP), which has yet to be shown to improve outcomes, and extracorporeal membrane oxygenation (ECMO), which requires super-specialised techniques not widely available. We report a case of Anterior STEMI from a left main stem occlusion suffering with cardiac arrest on reaching the catheter laboratory table necessitating external mechanical compression with an Autopulse™. The patient remained in pulseless electrical activity (PEA) throughout, and was Autopulse dependent despite successful percutaneous coronary intervention (PCI). An Impella® was inserted for additional mechanical support and facilitated successful weaning from cardiopulmonary resuscitation (CPR). Despite 105minutes without a spontaneous output, we describe the first documented case of simultaneous use of Impella with mechanical CPR with a successful outcome; demonstrating a potential technique of good mechanical haemodynamic support to aide early revascularisation that may have potential utility in the treatment of cardiogenic shock and arrest.


Subject(s)
Chest Wall Oscillation/methods , Extracorporeal Membrane Oxygenation/methods , Heart Arrest/surgery , Myocardial Infarction/surgery , Percutaneous Coronary Intervention/methods , Humans , Male , Middle Aged
13.
Coron Artery Dis ; 27(3): 233-43, 2016 May.
Article in English | MEDLINE | ID: mdl-26751424

ABSTRACT

The pathogenesis that underlies acute myocardial infarction is complex and multifactorial. One of the most important components, however, is the role of thrombus formation following atherosclerotic plaque rupture, leading to sudden coronary occlusion and subsequent ischemia and infarction. Thrombus aspiration provides the opportunity of intracoronary clot extraction with the aim to improve coronary and myocardial perfusion, by reducing the risk of no-reflow secondary to distal embolization of thrombus. The utility of thrombus aspiration during primary percutaneous coronary intervention has been assessed in an increasing number of observational and randomized studies. This article reviews the contemporary data and provides insights into the validity of thrombus aspiration in the setting of acute myocardial infarction.


Subject(s)
Clinical Trials as Topic , Coronary Thrombosis/therapy , Evidence-Based Medicine , Myocardial Infarction/therapy , Percutaneous Coronary Intervention , Thrombectomy , Clinical Trials as Topic/standards , Coronary Thrombosis/complications , Coronary Thrombosis/diagnosis , Coronary Thrombosis/mortality , Evidence-Based Medicine/standards , Humans , Myocardial Infarction/diagnosis , Myocardial Infarction/etiology , Myocardial Infarction/mortality , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Percutaneous Coronary Intervention/standards , Practice Guidelines as Topic/standards , Risk Factors , Thrombectomy/adverse effects , Thrombectomy/mortality , Thrombectomy/standards , Treatment Outcome
16.
Eur J Cardiothorac Surg ; 40(5): 1131-7, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21459016

ABSTRACT

OBJECTIVE: Preoperative left ventricular systolic function is an important prognostic factor in patients undergoing mitral valve surgery. Preoperative myocardial deformation may be impaired without reduction in conventional indices such as ejection fraction (EF). Strain rate (SR) imaging is very sensitive in detecting regional systolic abnormalities and might allow diagnosis of subclinical changes in systolic left ventricular (LV) function before surgery. We aimed to investigate the value of preoperative regional myocardial peak systolic SR as a predictor of postoperative LV systolic function in patients with severe mitral regurgitation (MR) undergoing surgery. METHODS: A total of 62 patients (age 52±12) with chronic severe MR, who underwent mitral valve repair, were studied. A standard echo examination, extended with tissue Doppler, was performed before and at 12 months after surgery. For the evaluation of longitudinal function, mid-ventricular segment shortening was analysed for the septum, LV lateral wall and anterior and inferior walls. RESULTS: Patients were divided into two groups based on postoperative EF: group 1 with EF(post-op)>50% and group 2 with EF(post-op)<50%. Group 1 had a significantly (p=0.004) higher preoperative SR (LV lateral wall: -1.97±0.26s(-1); septum: -1.74±0.31s(-1); anterior wall: -1.94±0.30s(-1), inferior wall: -1.93±0.29s(-1)) compared to group 2 (LV lateral wall: -0.98±0.23s(-1); septum: -0.98±0.26s(-1); anterior wall: -0.94±0.30s(-1), inferior wall: -1.00±0.24s(-1)). When SR was corrected for size, the SR/EDV index (EDV is end diastolic volume) also showed significant changes (p=0.0007) at baseline between the groups. For detecting subclinical changes in deformation of the LV lateral wall, a cut-off value of the SR/EDV index<0.006 had 89% sensitivity and 93% specificity; for the anterior wall, SR/EDV index<0.005 had 88% sensitivity and 94% specificity. CONCLUSIONS: SR imaging (corrected for geometry) can detect abnormalities in LV function at subclinical levels in patients with severe mitral regurgitation.


Subject(s)
Mitral Valve Insufficiency/surgery , Mitral Valve/surgery , Ventricular Dysfunction, Left/etiology , Adult , Aged , Chronic Disease , Echocardiography, Doppler/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve Insufficiency/complications , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/physiopathology , Postoperative Complications , Preoperative Care/methods , Prognosis , Stroke Volume/physiology , Systole/physiology , Treatment Outcome , Ventricular Dysfunction, Left/diagnostic imaging
17.
Hypertension ; 56(2): 253-9, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20585106

ABSTRACT

Microvascular rarefaction occurs in hypertension. We carried out a 12-week randomized double-blind crossover trial to determine the effect of a modest reduction in salt intake on capillary rarefaction in 71 whites, 69 blacks, and 29 Asians with untreated mildly raised blood pressure. Both basal and maximal (during venous congestion) skin capillary density were measured by capillaroscopy at the dorsum and the side of the fingers. In addition, we used orthogonal polarization spectral imaging to measure skin capillary density at the dorsum of the fingers and the hand web. With a reduction in salt intake from 9.7 to 6.5 g/day, there was an increase in capillary density (capillaries per millimeter squared) from 101+/-21 to 106+/-23 (basal) and 108+/-22 to 115+/-22 (maximal) at the dorsum, and 101+/-25 to 107+/-26 (basal) and 110+/-26 to 116+/-26 (maximal) at the side of the fingers (P<0.001 for all). Orthogonal polarization spectral imaging also showed a significant increase in capillary density both at the dorsum of the fingers and the web. Subgroup analysis showed that most of the changes were significant in all of the ethnic groups. Furthermore, there was a significant relationship between the change in 24-hour urinary sodium and the change in capillary density at the side of the fingers. These results demonstrate that a modest reduction in salt intake, as currently recommended, improves both functional and structural capillary rarefactions that occur in hypertension, and a larger reduction in salt intake would have a greater effect. The increase in capillary density may possibly carry additional beneficial effects on target organs.


Subject(s)
Capillaries/physiopathology , Diet, Sodium-Restricted , Hypertension/prevention & control , Hypertension/physiopathology , Skin/blood supply , Adult , Aged , Aldosterone/blood , Asian People , Black People , Capillaries/anatomy & histology , Double-Blind Method , Fingers/blood supply , Hemoglobins/metabolism , Humans , Hypertension/blood , Microscopy, Video/methods , Middle Aged , Placebos , Polarography/methods , Renin/blood , Systole/physiology , White People
18.
Hypertension ; 55(3): 681-8, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20083724

ABSTRACT

To determine the effects of potassium supplementation on endothelial function, cardiovascular risk factors, and bone turnover and to compare potassium chloride with potassium bicarbonate, we carried out a 12-week randomized, double-blind, placebo-controlled crossover trial in 42 individuals with untreated mildly raised blood pressure. Urinary potassium was 77+/-16, 122+/-25, and 125+/-27 mmol/24 hours after 4 weeks on placebo, potassium chloride, and potassium bicarbonate, respectively. There were no significant differences in office blood pressure among the 3 treatment periods, and only 24-hour and daytime systolic blood pressures were slightly lower with potassium chloride. Compared with placebo, both potassium chloride and potassium bicarbonate significantly improved endothelial function as measured by brachial artery flow-mediated dilatation, increased arterial compliance as assessed by carotid-femoral pulse wave velocity, decreased left ventricular mass, and improved left ventricular diastolic function. There was no significant difference between the 2 potassium salts in these measurements. The study also showed that potassium chloride reduced 24-hour urinary albumin and albumin:creatinine ratio, and potassium bicarbonate decreased 24-hour urinary calcium, calcium:creatinine ratio, and plasma C-terminal cross-linking telopeptide of type 1 collagen significantly. These results demonstrated that an increase in potassium intake had beneficial effects on the cardiovascular system, and potassium bicarbonate may improve bone health. Importantly, these effects were found in individuals who already had a relatively low-salt and high-potassium intake.


Subject(s)
Bicarbonates/administration & dosage , Bone Remodeling/drug effects , Endothelium, Vascular/drug effects , Hypertension/drug therapy , Potassium Chloride/administration & dosage , Potassium Compounds/administration & dosage , Adult , Albuminuria/drug therapy , Albuminuria/epidemiology , Albuminuria/physiopathology , Blood Pressure/drug effects , Bone Remodeling/physiology , Brachial Artery/drug effects , Brachial Artery/physiology , Calcium/urine , Cross-Over Studies , Female , Humans , Hypertension/epidemiology , Hypertension/physiopathology , Hypertrophy, Left Ventricular/drug therapy , Hypertrophy, Left Ventricular/epidemiology , Hypertrophy, Left Ventricular/physiopathology , Male , Middle Aged , Potassium/urine , Pulsatile Flow/drug effects , Risk Factors , Severity of Illness Index , Sodium Chloride, Dietary/administration & dosage
19.
J Hypertens ; 27(10): 2086-93, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19738493

ABSTRACT

BACKGROUND AND OBJECTIVES: Early changes in left atrial function in hypertension are difficult to assess quantitatively. Measuring atrial reversal flow into the pulmonary veins and regional left atrial deformation parameters assessed by Tissue Doppler-derived strain/rate (S/SR) imaging could provide quantitative assessment of left atrial deformation. We aimed to quantify changes in left atrial volume and deformation and pulmonary flow reversal (PVREVERS) in hypertension to detect subclinical left atrial dysfunction. DESIGN, SETTING AND PATIENTS: In 74 hypertensive and 34 age-matched normotensive patients (mean age 49 +/- 1.4 vs. 44.2 +/- 2.1 years) echo studies were performed, including measurements of LAV during reservoir, conduit and pump phases and standard indices reflecting left ventricular filling. S/SR was measured in the lateral left atrial wall. Total deformation (STOTAL) and the contribution to early (SE-index) and late (SA-index) filling were calculated. RESULTS: Hypertensive patients had significantly impaired diastolic function and increased left atrial volume during all phases. Only LAVCONDUIT significantly correlated with both ventricular hypertrophy and parameters of diastolic function. Velocity time integral of PVREVERS correlated with blood pressure and LAVCONDUIT. In hypertensive patients STOTAL was significantly higher (54.9 +/- 2.6 vs. 45.5 +/- 2.7%, P < 0.03) and SE-index was lower (P < 0.0001). This was compensated for by an increased SA-index (P < 0.0001) and SR during atrial contraction (-4.9 +/- 0.2 vs. -2.9 +/- 0.3 1/s, P < 0.0001). SA-index correlated significantly with blood pressure (R = 0.4; P < 0.0001) and PVREVERS (R = 0.3; P < 0.001). CONCLUSION: Changes in left atrial function due to hypertensive diastolic impairment are best reflected by LAVCONDUIT expansion. Hypertensive atrial dilatation is related to increase in PVREVERS. Left atrial S/SR offers a clinically valuable approach to detecting subclinical atrial dysfunction.


Subject(s)
Atrial Function, Left/physiology , Cardiomegaly/diagnostic imaging , Cardiomegaly/etiology , Echocardiography, Doppler/methods , Hypertension/complications , Hypertension/diagnostic imaging , Adult , Blood Pressure/physiology , Diastole/physiology , Echocardiography, Doppler/standards , Female , Humans , Male , Middle Aged , Reproducibility of Results , Severity of Illness Index
20.
Hypertension ; 54(3): 482-8, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19620514

ABSTRACT

A reduction in salt intake lowers blood pressure. However, most previous trials were in whites with few in blacks and Asians. Salt reduction may also reduce other cardiovascular risk factors (eg, urinary albumin excretion, arterial stiffness). However, few well-controlled trials have studied these effects. We carried out a randomized double-blind crossover trial of salt restriction with slow sodium or placebo, each for 6 weeks, in 71 whites, 69 blacks, and 29 Asians with untreated mildly raised blood pressure. From slow sodium to placebo, urinary sodium was reduced from 165+/-58 (+/-SD) to 110+/-49 mmol/24 hours (9.7 to 6.5 g/d salt). With this reduction in salt intake, there was a significant decrease in blood pressure from 146+/-13/91+/-8 to 141+/-12/88+/-9 mm Hg (P<0.001), urinary albumin from 10.2 (IQR: 6.8 to 18.9) to 9.1 (6.6 to 14.0) mg/24 hours (P<0.001), albumin/creatinine ratio from 0.81 (0.47 to 1.43) to 0.66 (0.44 to 1.22) mg/mmol (P<0.001), and carotid-femoral pulse wave velocity from 11.5+/-2.3 to 11.1+/-1.9 m/s (P<0.01). Subgroup analysis showed that the reductions in blood pressure and urinary albumin/creatinine ratio were significant in all groups, and the decrease in pulse wave velocity was significant in blacks only. These results demonstrate that a modest reduction in salt intake, approximately the amount of the current public health recommendations, causes significant falls in blood pressure in all 3 ethnic groups. Furthermore, it reduces urinary albumin and improves large artery compliance. Although both could be attributable to the falls in blood pressure, they may carry additional benefits on reducing cardiovascular disease above that obtained from the blood pressure falls alone.


Subject(s)
Albuminuria/urine , Blood Pressure/drug effects , Diet, Sodium-Restricted , Heart Rate/drug effects , Hypertension/diet therapy , Sodium Chloride, Dietary/administration & dosage , Adult , Aged , Asian People/statistics & numerical data , Black People/statistics & numerical data , Cross-Over Studies , Double-Blind Method , Female , Humans , Hypertension/ethnology , Hypertension/physiopathology , Male , Middle Aged , Potassium/blood , Potassium/urine , Sodium/blood , Sodium/urine , Time Factors , White People/statistics & numerical data
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