1
|
Neumann S, Hamilton MCK, Hart EC, Brooks JCW. Pain perception during baroreceptor unloading by lower body negative pressure. Eur J Pain 2024. [PMID: 38623884 DOI: 10.1002/ejp.2273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 03/19/2024] [Accepted: 03/21/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND People with high blood pressure have reduced sensitivity to pain, known as blood pressure hypoalgesia. One proposed mechanism for this is altered baroreceptor sensitivity. In healthy volunteers, stimulating the carotid baroreceptors causes reduced sensitivity to acute pain; however, this effect may be confounded by a rise in blood pressure due to baroreflex stimulation. The present study tests whether baroreceptor unloading contributes to the physiological mechanism of blood pressure-related hypoalgesia. METHODS In the present study, pain perception to thermal stimulation of the forearm was studied in 20 healthy volunteers during baroreceptor unloading by lower body negative pressure (LBNP) at -5 and -20 mmHg. Blood pressure and heart rate were measured continuously throughout. To address issues relating to stimulation order, the sequence of LBNP stimulation was counterbalanced across participants. RESULTS Increased heart rate was observed at a LBNP of -20 mmHg, but not -5 mmHg, but neither stimulus had an effect on blood pressure. There was no change in warm or cold sensory detection thresholds, heat or cold pain thresholds nor perceived pain from a 30s long thermal heat stimulus during LBNP. CONCLUSION Therefore, baroreceptor unloading with maintained systemic blood pressure did not alter pain perception. The current study does not support the hypothesis that an altered baroreflex may underlie the physiological mechanism of blood pressure-related hypoalgesia. SIGNIFICANCE This work provides evidence that, when measured in normotensive healthy young adults, the baroreflex response to simulated hypovolaemia did not lead to reduced pain sensitivity (known as blood pressure hypoalgesia).
Collapse
Affiliation(s)
- S Neumann
- Clinical Trials Unit, University of Bristol, Bristol, UK
| | - M C K Hamilton
- University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - E C Hart
- School of Physiology Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - J C W Brooks
- School of Psychology, University of East Anglia, Norwich, UK
| |
Collapse
|
2
|
Erdei T, Rodrigues JCL, Hartley-Davies R, Dastidar AG, Szantho GV, Hart EC, Nightingale AK, Manghat NE, Hamilton MCK. The effect of left ventricular longitudinal strain on left atrial function and ventricular filling in hypertension. Clin Radiol 2022; 77:e379-e386. [PMID: 35303990 DOI: 10.1016/j.crad.2022.01.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 01/18/2022] [Indexed: 11/16/2022]
Abstract
AIM To assess the relationship of global longitudinal strain during left atrial (LA) and left ventricular (LV) filling and emptying. MATERIALS AND METHODS Using magnetic resonance imaging in 47 hypertensive patients, biplane global LV longitudinal strain was evaluated and related to LA and LV filling and emptying (by volumetric analysis), and to pulmonary vein and trans-mitral flow (by phase-contrast imaging). The results were compared to normal subjects. RESULTS In hypertensive patients, reduced global longitudinal LV strain was associated with reduced LA reservoir (47 ± 10 versus 53 ± 9%, p<0.05), reduced LA conduit function (21 ± 9 versus 32 ± 11%, p<0.004), reduced LA early peak emptying rate (150 ± 77 versus 230 ± 88 ml/s, p=0.007), and slower early LV filling (373 ± 141 versus 478 ± 141 ml/s, p=0.03). LA peak filling rate showed a positive correlation to LV peak emptying rate (R=0.331, p=0.02). CONCLUSION In hypertensive heart disease, impaired LV longitudinal systolic function causes reduced LA filling and emptying, and this leads directly to impaired LV filling and diastolic dysfunction.
Collapse
Affiliation(s)
- T Erdei
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK
| | - J C L Rodrigues
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK; Clinical Radiology, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol BS2 8HW, UK; Cardionomics Research Group, University of Bristol, Bristol BS8 1TY, UK
| | - R Hartley-Davies
- Medical Physics, University Hospitals Bristol NHS Foundation Trust, Bristol BS2 8HW, UK
| | - A G Dastidar
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK
| | - G V Szantho
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK
| | - E C Hart
- Cardionomics Research Group, University of Bristol, Bristol BS8 1TY, UK
| | - A K Nightingale
- Cardionomics Research Group, University of Bristol, Bristol BS8 1TY, UK
| | - N E Manghat
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK; Clinical Radiology, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol BS2 8HW, UK; Cardionomics Research Group, University of Bristol, Bristol BS8 1TY, UK
| | - M C K Hamilton
- CMR Unit, Bristol Heart Institute, Bristol BS2 8HW, UK; Clinical Radiology, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol BS2 8HW, UK.
| |
Collapse
|
3
|
Neumann S, Sophocleous F, Kobetic MD, Hart EC, Nightingale AK, Parker KH, Hamilton MK, Biglino G. Wave intensity analysis in the internal carotid artery of hypertensive subjects using phase-contrast MR angiography and preliminary assessment of the effect of vessel morphology on wave dynamics. Physiol Meas 2018; 39:104003. [PMID: 30192235 PMCID: PMC6372132 DOI: 10.1088/1361-6579/aadfc5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Objective: Hypertension is associated with reduced cerebral blood flow, but it is not known how this impacts on wave dynamics or potentially relates to arterial morphology. Given the location of the internal carotid artery (ICA) and risks associated with invasive measurements, wave dynamics in this artery have not been extensively assessed in vivo. This study explores the feasibility of studying wave dynamics in the internal carotid artery non-invasively. Approach: Normotensive, uncontrolled and controlled hypertensive participants were recruited (daytime ambulatory blood pressure <135/85 mmHg and >135/85 mmHg, respectively; n = 38). Wave intensity, reservoir pressure and statistical shape analyses were performed on the right ICA and ascending aorta high-resolution phase-contrast magnetic resonance angiography data. Main results: Wave speed in the aorta was significantly lower in normotensive compared to hypertensive participants (6.7 ± 1.8 versus 11.2 ± 6.2 m s−1 for uncontrolled and 11.8 ± 4.6 m s−1 for controlled hypertensives, p = 0.02), whilst there were no differences in wave speed in the ICA. There were no significant differences between the groups for the wave intensity or reservoir pressure. Interestingly, a significant association between the anatomy of the ICA and wave energy (FCW and size, r2 = 0.12, p = 0.04) was found. Significance: This study shows it is feasible to study wave dynamics in the ICA non-invasively. Whilst changes in aortic wave speed confirmed an expected increase in arterial stiffness, this was not observed in the ICA. This might suggest a protective mechanism in the cerebral circulation, in conjunction with the effect of vessel tortuosity. Furthermore, it was observed that ICA shape correlated with wave energy but not wave speed.
Collapse
Affiliation(s)
- S Neumann
- University of Bristol, Bristol, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Briant LJB, Charkoudian N, Hart EC. Sympathetic regulation of blood pressure in normotension and hypertension: when sex matters. Exp Physiol 2016; 101:219-29. [PMID: 26682826 DOI: 10.1113/ep085368] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/14/2015] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the topic of this review? Hypertension is a major problem in Western society. Risk of hypertension increases with age, especially in women, who have lower risk compared with men until menopause. This review outlines the sex differences in the sympathetic control of blood pressure and how these mechanisms change with age. What advances does it highlight? It has recently been recognized that men and women regulate blood pressure by different physiological mechanisms. This is important for both the understanding and the clinical management of individual patients with hypertension. This review summarizes recent advances in understanding how the regulation of blood pressure in hypertension by the sympathetic nervous system differs between men and women. The sympathetic nervous system has a central role in the regulation of arterial blood pressure (BP) and in the development of hypertension in humans. Recent evidence points to differences between the sexes in the integrative mechanisms by which BP is controlled, suggesting that the development of hypertension may follow distinct pathways in women compared with men. An important aspect of sympathetic control of BP is its substantial interindividual variability. In healthy young men, the variability in sympathetic nerve activity (SNA) is balanced by variability in cardiac output and vascular adrenergic responses, such that BP remains similar, and normal, across a severalfold range of resting SNA values. In young women, variability in resting SNA is similar to that seen in men, but the 'balancing' mechanisms are strikingly different; women exhibit greater β-adrenergic vasodilatation compared with men, which minimizes the pressor effects of a given level of SNA. Ageing is associated with increased SNA and a loss of the balancing factors seen in younger people, leading to an increased risk of hypertension in older people. Loss of oestrogen with menopause in women appears to be linked mechanistically with the decrease in β-adrenergic vasodilatation and the increased risk of hypertension in older women. Other important factors contributing to hypertension via sympathetic mechanisms are obesity and arterial stiffening, both of which increase with ageing. We conclude with a discussion of important areas in which more work is needed to understand and manage appropriately the sex-specific mechanisms in the development and maintenance of hypertension.
Collapse
Affiliation(s)
- L J B Briant
- Clinical Research and Imaging Centre, Cardionomics Group, University of Bristol, Bristol, UK
| | - N Charkoudian
- US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - E C Hart
- Clinical Research and Imaging Centre, Cardionomics Group, University of Bristol, Bristol, UK
| |
Collapse
|
5
|
Rodrigues JCL, Erdei T, Dastidar AG, McIntyre B, Burchell AE, Ratcliffe LEK, Hart EC, Hamilton MCK, Paton JFR, Nightingale AK, Manghat NE. Electrocardiographic detection of hypertensive left atrial enlargement in the presence of obesity: re-calibration against cardiac magnetic resonance. J Hum Hypertens 2016; 31:212-219. [PMID: 27604657 DOI: 10.1038/jhh.2016.63] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/07/2016] [Accepted: 07/27/2016] [Indexed: 12/31/2022]
Abstract
Left atrial enlargement (LAE) has adverse prognostic implications in hypertension. We sought to determine the accuracy of five electrocardiogram (ECG) criteria for LAE in hypertension relative to cardiac magnetic resonance (CMR) gold standard and investigate the effect of concomitant obesity. One hundred and thirty consecutive patients (age: 51.4±15.1 years, 47% male, 51% obese, systolic blood pressure (BP): 171±29 mm Hg, diastolic BP: 97±15 mm Hg) referred for CMR (1.5 T) from a tertiary hypertension clinic were included. Patients with concomitant cardiac pathology were excluded. ECGs were assessed blindly for the following: (1) P-wave >110 ms, (2) P-mitrale, (3) P-wave axis <30°, (4) area of negative P-terminal force in V1 >40 ms.mm and (5) positive P-terminal force in augmented vector left (aVL) >0.5 mm. Left atrial volume ≥55 ml m-2, measured blindly by CMR, was defined as LAE. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under the receiver operator curve were calculated. The prevalence of LAE by CMR was 26%. All the individual ECG LAE criteria were more specific than sensitive, with specificities ranging from 70% (P-axis <30o) to 99% (P-mitrale). Obesity attenuated the specificity of most of the individual ECG LAE criteria. Obesity correlated with significant lower specificity (48% vs 65%, P<0.05) and a trend towards lower sensitivity (59 vs 43%, P=0.119) when ≥1 ECG LAE criteria were present. Individual ECG criteria of LAE in hypertension are specific, but not sensitive, at identifying LAE. The ECG should not be used to excluded LAE in hypertension, particularly in obese subjects.
Collapse
Affiliation(s)
- J C L Rodrigues
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Faculty of Biomedical Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - T Erdei
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - A G Dastidar
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - B McIntyre
- Severn Postgraduate Medical Education Foundation School, NHS Health Education South West, Bristol, UK
| | - A E Burchell
- CardioNomics Research Group, Clinical Imaging and Research Centre, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - L E K Ratcliffe
- CardioNomics Research Group, Clinical Imaging and Research Centre, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - E C Hart
- Faculty of Biomedical Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,CardioNomics Research Group, Clinical Imaging and Research Centre, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - M C K Hamilton
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - J F R Paton
- Faculty of Biomedical Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,CardioNomics Research Group, Clinical Imaging and Research Centre, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - A K Nightingale
- Faculty of Biomedical Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,CardioNomics Research Group, Clinical Imaging and Research Centre, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - N E Manghat
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| |
Collapse
|
6
|
Briant LJB, Burchell AE, Ratcliffe LEK, Charkoudian N, Nightingale AK, Paton JFR, Joyner MJ, Hart EC. Quantifying sympathetic neuro-haemodynamic transduction at rest in humans: insights into sex, ageing and blood pressure control. J Physiol 2016; 594:4753-68. [PMID: 27068560 DOI: 10.1113/jp272167] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/04/2016] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS We have developed a simple analytical method for quantifying the transduction of sympathetic activity into vascular tone. This method demonstrates that as women age, the transfer of sympathetic nerve activity into vascular tone is increased, so that for a given level of sympathetic activity there is more vasoconstriction. In men, this measure decreases with age. Test-re-test analysis demonstrated that the new method is a reliable estimate of sympathetic transduction. We conclude that increased sympathetic vascular coupling contributes to the age-related increase in blood pressure that occurs in women only. This measure is a reliable estimate of sympathetic transduction in populations with high sympathetic nerve activity. Thus, it will provide information regarding whether treatment targeting the sympathetic nervous system, which interrupts the transfer of sympathetic nerve activity into vascular tone, will be effective in reducing blood pressure in hypertensive patients. This may provide insight into which populations will respond to certain types of anti-hypertensive medication. ABSTRACT Sex and age differences in the sympathetic control of resting blood pressure (BP) may be due to differences in the transduction of sympathetic nerve activity (SNA) into vascular tone. Current methods for dynamically quantifying transduction focus on the relationship between SNA and vasoconstriction during a pressor stimulus, which increases BP and may be contra-indicated in patients. We describe a simple analytical method for quantifying transduction under resting conditions. We performed linear regression analysis of binned muscle SNA burst areas against diastolic BP (DBP). We assessed whether the slope of this relationship reflects the transduction of SNA into DBP. To evaluate this, we investigated whether this measure captures differences in transduction in different populations. Specifically, we (1) quantified transduction in young men (YM), young women (YW), older men (OM) and postmenopausal women (PMW); and (2) measured changes in transduction during β-blockade using propranolol in YW, YM and PMW. YM had a greater transduction vs. OM (0.10 ± 0.01 mmHg (% s)(-1) , n = 23 vs. 0.06 ± 0.01 mmHg (% s)(-1) , n = 18; P = 0.003). Transduction was lowest in YW (0.02 ± 0.01 mmHg (% s)(-1) , n = 23) and increased during β-blockade (0.11 ± 0.01 mmHg (% s)(-1) ; P < 0.001). Transduction in PMW (0.07 ± 0.01 mmHg (% s)(-1) , n = 23) was greater compared to YW (P = 0.001), and was not altered during β-blockade (0.06 ± 0.01 mmHg (% s)(-1) ; P = 0.98). Importantly, transduction increased in women with age, but decreased in men. Transduction in women intersected that in men at 55 ± 1.5 years. This measure of transduction captures age- and sex-differences in the sympathetic regulation of DBP and may be valuable in quantifying transduction in disease. In particular, this measure may help target treatment strategies in specific hypertensive subpopulations.
Collapse
Affiliation(s)
- L J B Briant
- CardioNomics, CRIC Bristol, University of Bristol, Bristol, UK
| | - A E Burchell
- CardioNomics, CRIC Bristol, University of Bristol, Bristol, UK
| | - L E K Ratcliffe
- CardioNomics, CRIC Bristol, University of Bristol, Bristol, UK
| | - N Charkoudian
- US Army Research Institute of Environmental Medicine, Natick, MA, USA
| | - A K Nightingale
- Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - J F R Paton
- School of Physiology and Pharmacology, Biomedical Sciences, University of Bristol, Bristol, UK
| | | | - E C Hart
- CardioNomics, CRIC Bristol, University of Bristol, Bristol, UK.,School of Physiology and Pharmacology, Biomedical Sciences, University of Bristol, Bristol, UK
| |
Collapse
|
7
|
Erdei T, Rodrigues JC, McIntyre B, Dastidar AG, Burchell AE, Ratcliffe L, Hart EC, Paton JF, Hamilton M, Nightingale AK, Manghat NE. 8 Diagnostic performance of ECG detection of left atrial enlargement in patients with arterial hypertension relative to the cardiac magnetic resonance gold-standard: Impact of obesity: Abstract 8 Table 1. Heart 2016. [DOI: 10.1136/heartjnl-2016-309668.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
8
|
Ratcliffe LEK, Pijacka W, McBryde FD, Abdala AP, Moraes DJ, Sobotka PA, Hart EC, Narkiewicz K, Nightingale AK, Paton JFR. CrossTalk opposing view: Which technique for controlling resistant hypertension? Carotid chemoreceptor denervation/modulation. J Physiol 2015; 592:3941-4. [PMID: 25225253 DOI: 10.1113/jphysiol.2013.268227] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- L E K Ratcliffe
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - W Pijacka
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - F D McBryde
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - A P Abdala
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - D J Moraes
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - P A Sobotka
- The Ohio State University, 2015 Marywood Lane West, St Paul, MN, 55118, USA
| | - E C Hart
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - K Narkiewicz
- Department of Hypertension and Diabetology, Medical University of Gdansk, Debinki 7c, 80-952, Gdansk, Poland
| | - A K Nightingale
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - J F R Paton
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| |
Collapse
|
9
|
Rodrigues JCL, McIntyre B, Dastidar AG, Lyen SM, Ratcliffe LE, Burchell AE, Hart EC, Bucciarelli-Ducci C, Hamilton MCK, Paton JFR, Nightingale AK, Manghat NE. The effect of obesity on electrocardiographic detection of hypertensive left ventricular hypertrophy: recalibration against cardiac magnetic resonance. J Hum Hypertens 2015; 30:197-203. [PMID: 26040440 PMCID: PMC4750022 DOI: 10.1038/jhh.2015.58] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/10/2015] [Accepted: 04/29/2015] [Indexed: 01/20/2023]
Abstract
Electrocardiograph (ECG) criteria for left ventricular hypertrophy (LVH) are a widely used clinical tool. We recalibrated six ECG criteria for LVH against gold-standard cardiac magnetic resonance (CMR) and assessed the impact of obesity. One hundred and fifty consecutive tertiary hypertension clinic referrals for CMR (1.5 T) were reviewed. Patients with cardiac pathology potentially confounding hypertensive LVH were excluded (n=22). The final sample size was 128 (age: 51.0±15.2 years, 48% male). LVH was defined by CMR. From a 12-lead ECG, Sokolow–Lyon voltage and product, Cornell voltage and product, Gubner–Ungerleidger voltage and Romhilt–Estes score were evaluated, blinded to the CMR. ECG diagnostic performance was calculated. LVH by CMR was present in 37% and obesity in 51%. Obesity significantly reduced ECG sensitivity, because of significant attenuation in mean ECG values for Cornell voltage (22.2±5.7 vs 26.4±9.4 mm, P<0.05), Cornell product (2540±942 vs 3023±1185 mm • ms, P<0.05) and for Gubner–Ungerleider voltage (18.2±7.1 vs 23.3±1.2 mm, P<0.05). Obesity also significantly reduced ECG specificity, because of significantly higher prevalence of LV remodeling (no LVH but increased mass-to-volume ratio) in obese subjects without LVH (36% vs 16%, P<0.05), which correlated with higher mean ECG LVH criteria values. Obesity-specific partition values were generated at fixed 95% specificity; Cornell voltage had highest sensitivity in non-obese (56%) and Sokolow–Lyon product in obese patients (24%). Obesity significantly lowers ECG sensitivity at detecting LVH, by attenuating ECG LVH values, and lowers ECG specificity through changes associated with LV remodeling. Our obesity-specific ECG partition values could improve the diagnostic performance in obese patients with hypertension.
Collapse
Affiliation(s)
- J C L Rodrigues
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK
| | - B McIntyre
- Severn Postgraduate Medical Education Foundation School, NHS Health Education South West, Bristol, UK
| | - A G Dastidar
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - S M Lyen
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - L E Ratcliffe
- Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - A E Burchell
- Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - E C Hart
- School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.,Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - C Bucciarelli-Ducci
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - M C K Hamilton
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - J F R Paton
- School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.,Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - A K Nightingale
- School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.,Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - N E Manghat
- NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.,Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| |
Collapse
|
10
|
Ratcliffe LEK, Pijacka W, McBryde FD, Abdala AP, Moraes DJ, Sobotka PA, Hart EC, Narkiewicz K, Nightingale AK, Paton JFR. Rebuttal from L. E. K. Ratcliffe, W. Pijacka, F. D. McBryde, A. P. Abdala, D. J. Moraes, P. A. Sobotka, E. C. Hart, K. Narkiewicz, A. K. Nightingale and J. F. R. Paton. J Physiol 2014; 592:3949-50. [PMID: 25225256 DOI: 10.1113/jphysiol.2014.279737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- L E K Ratcliffe
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - W Pijacka
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - F D McBryde
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - A P Abdala
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - D J Moraes
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - P A Sobotka
- The Ohio State University, 2015 Marywood Lane West, St Paul, MN, 55118, USA
| | - E C Hart
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - K Narkiewicz
- Department of Hypertension and Diabetology, Medical University of Gdansk, Debinki 7c, 80-952 Gdansk, Poland
| | - A K Nightingale
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| | - J F R Paton
- CardioNomics Research Group, Clinical Research and Imaging Centre and School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
| |
Collapse
|
11
|
Fraas MR, Coughlan GF, Hart EC, McCarthy C. Concussion knowledge and management practices among coaches and medical staff in Irish professional rugby teams. Ir J Med Sci 2014; 184:425-30. [DOI: 10.1007/s11845-014-1137-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 05/05/2014] [Indexed: 10/25/2022]
|
12
|
Amy AE, Ratcliffe LEK, Hart EC, Stewart LQ, Baumbach A, Paton JFR, Nightingale AK. 131 RENAL DENERVATION FOR RESISTANT HYPERTENSION: SAFETY AND RESPONSE RATE AT 6 MONTHS IN A UK POPULATION. Heart 2013. [DOI: 10.1136/heartjnl-2013-304019.131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
13
|
Ratcliffe LEK, Hart EC, Burchell AE, Baumbach A, Paton JFR, Nightingale AK. 130 RENAL DENERVATION IMPROVES AUTONOMIC RESPONSES TO FALLS IN BLOOD PRESSURE. Heart 2013. [DOI: 10.1136/heartjnl-2013-304019.130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
14
|
Abstract
AIM Alterations in the carotid baroreflex (CBR) control of arterial pressure may explain the reduction in arterial pressure and left ventricular (LV) function after prolonged exercise. We examined the CBR control of heart rate (HR) and mean arterial pressure (MAP), in addition to changes in LV function, pre- to post-exercise. METHODS Seven males (age, mean ± SEM; 29 ± 4 years) completed 4 h of ergometer rowing at a workload of 10-15% below the lactate threshold. The CBR control of HR and MAP was assessed via the rapid neck-suction/pressure protocol. LV systolic function was measured by echocardiography, where ejection fraction (EF), the ratio of systolic blood pressure to end systolic volume (SBP/ESV) and stroke volume (SV) were estimated. RESULTS Following exercise MAP was reduced (12 ± 3%) and HR was elevated (35 ± 5%; P < 0.05). Furthermore, CBR control of MAP was relocated to the left on the stimulus-response curve (P < 0.05) demonstrating that the CBR operated around a lower arterial pressure. Concomitantly, LV systolic function was reduced, indicated by a decrease in EF (22 ± 2%), SBP/ESV (32 ± 14%) and SV (25 ± 5%, P < 0.05). The reduced EF and SBP/ESV were associated with the decreased MAP operating point (r² = 0.71 and r² = 0.47, respectively, P < 0.05). CONCLUSION The CBR is reset after prolonged exercise to a lower prevailing arterial pressure. This resetting of the CBR may contribute to the reduction arterial pressure and LV function after exercise.
Collapse
Affiliation(s)
- E C Hart
- Centre for Sports Medicine and Human Performance, Brunel University, London, UK.
| | | | | | | | | | | | | |
Collapse
|
15
|
Wallin BG, Hart EC, Wehrwein EA, Charkoudian N, Joyner MJ. Relationship between breathing and cardiovascular function at rest: sex-related differences. Acta Physiol (Oxf) 2010; 200:193-200. [PMID: 20345407 DOI: 10.1111/j.1748-1716.2010.02126.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM to compare relationships at rest between breathing rate, levels of muscle sympathetic nerve activity, total peripheral resistance and cardiac output among young men and women. METHODS recordings were made of respiratory movements, sympathetic nerve activity (peroneal microneurography), intra-arterial blood pressure, electrocardiogram, cardiac output (open-circuit acetylene uptake technique) in 19 healthy men (age 27 (+/-) 2years, mean (+/-) SEM) and 17 healthy women (age 25 (+/-) 1years). Total peripheral resistance and stroke volume were calculated. Four minutes epochs of data were analysed. RESULTS breathing rates and sympathetic activity were similar in men and women but compared to men, women had significantly lower blood pressures, cardiac output and stroke volume. In men breathing rate correlated positively with sympathetic activity (r = 0.58, P < 0.05) but not in women (r = 0.12, P > 0.05). Furthermore, in men, respiratory rate correlated positively with total peripheral resistance (r = 0.65, P < 0.05) and inversely with cardiac output (r =-0.84, P < 0.05) and heart rate (r = -0.60, P < 0.05) but there were no such relationships in women (P > 0.05 for all). CONCLUSIONS the positive relationship between breathing and sympathetic activity in men, and the inverse coupling of breathing to cardiac output and heart rate suggest that influences of respiration may be important not only for dynamic but also for 'tonic' cardiovascular function. The lack of relationships among these variables in women shows that there are fundamental differences in basic blood pressure regulation between the sexes.
Collapse
Affiliation(s)
- B G Wallin
- Department of ClinicalNeurophysiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.
| | | | | | | | | |
Collapse
|
16
|
Wehrwein EA, Hart EC, Charkoudian N, Joyner MJ, Widmer RJ, Eisenach JH, Wallin BG. Relationship between breathing and cardiovascular function at rest: Sex related differences. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1020.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | | | - BG Wallin
- Clinical NeuroscienceThe Sahlgren Academy at Gothenburg UniversityGothenburgSweden
| |
Collapse
|