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1.
J Hypertens ; 41(7): 1100-1107, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37071447

RESUMO

OBJECTIVE: Children and adolescents with adiposity excess are at increased risk of future cardiovascular (CV) disease. Fat accumulation promotes the development of elevated blood pressure (BP) and arterial stiffness, two main determinants of CV risk which are strongly inter-related. We aimed at investigating whether the association between overweight and arterial stiffness, taken at different arterial segments, is mediated by increased BP or is BP-independent. METHODS: Three hundred and twenty-two Italian healthy adolescents (mean age 16.9±1.4 years, 12% with overweight) attending the "G. Donatelli" High School in Terni, Italy, underwent measurement of arterial stiffness by arterial tonometry (aortic stiffness) and semiautomatical detection of pressure-volume ratio of the common carotid (carotid stiffness). The mediator effect of BP was tested for each anthropometric or biochemical measure of fat excess related to arterial stiffness. RESULTS: Both carotid and aortic stiffness showed positive correlations with body mass index, waist, hip, and neck circumferences (NC). Only carotid stiffness, but not aortic stiffness, was associated with serum markers of fat accumulation and metabolic impairment such as insulin, homeostatic model of insulin resistance (HOMA-IR), serum gamma-glutamyl transferase (sGGT) and uric acid. The association with NC was stronger for carotid than for aortic stiffness (Fisher z -to- R 2.07, P  = 0.04), and independent from BP. CONCLUSIONS: In healthy adolescents, fat accumulation is associated with arterial stiffness. The degree of this association differs by arterial segments, since carotid stiffness is more strongly associated to adipose tissue excess than aortic stiffness and shows a BP-independent association with NC whereas aortic stiffness does not.


Assuntos
Doenças Cardiovasculares , Rigidez Vascular , Adolescente , Humanos , Adiposidade , Pressão Sanguínea , Artérias Carótidas , Obesidade/complicações , Sobrepeso/complicações , Fatores de Risco , Circunferência da Cintura
2.
Heart Lung Circ ; 30(11): 1734-1743, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34366219

RESUMO

OBJECTIVE: The objective of this work was to investigate technical validation and usability of an innovative, technically simple, easy-to-use, and portable integrated system to assess carotid function and structure by ultrasound. METHODS: The studied system integrated a hardware (the Interson SP-L01 embedded ultrasound probe [Interson, Pleasanton, CA, USA]) and a software measuring the instantaneous diameter of the carotid artery in real-time from B-mode ultrasound image sequences (Carotid Studio, by Quipu Srl [Pisa, Italy]). Technical validation was evaluated by intra-operator reproducibility of two measurements acquired by an expert operator, and agreement with state-of-the-art technique (Mylab25 by Esaote SpA [Genova, Italy], Carotid Studio 4.3 by Quipu Srl) was evaluated in laboratory settings in 12 healthy volunteers; usability of the portable integrated system was investigated by administering questionnaires to users and the results were reported with scores based on a five-point scale. RESULTS: Twelve (12) healthy volunteers (five men, mean age 44.5±13.6 years, free of cardiovascular disease or risk factors), were recruited. Agreement with state-of-the-art technique was satisfactory, with no significant bias. Coefficient of variation (intra-operator reproducibility) was 3.2% (2.5% SD) for intima-media thickness, 0.9% (0.7% SD) for diameter, and 2.5% (2.2% SD) for distension. Usability questionnaires showed an overall positive judgement of the integrated system with respect to the traditional one, obtaining an average score greater than 4 (on a five-point scale). CONCLUSIONS: A portable, innovative prototype to easily assess ultrasound carotid parameters of vascular ageing was successfully designed, developed, and demonstrated to be comparable with state-of-the art technique. Usability was also satisfactory.


Assuntos
Envelhecimento , Espessura Intima-Media Carotídea , Adulto , Artérias Carótidas/diagnóstico por imagem , Artéria Carótida Primitiva , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes , Ultrassonografia
3.
J Biomed Inform ; 93: 103150, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30878617

RESUMO

BACKGROUND AND OBJECTIVES: Similarly to what already established and implemented in the United States, the concept of the Unique Device Identification (UDI) system has been introduced with the European Regulations for medical devices MDR (EU) 2017/745 and in-vitro diagnostic medical devices IVDR (EU) 2017/746 and it is on the way to become a worldwide standard. The aim of this work was to provide a possible approach for the implementation of UDI and traceability in Europe for standalone software medical devices according to lifecycle and quality system standards. METHODS: The key points of the UDI regulation were determined and analyzed in order to identify the main issues related to the manufacturing of software medical devices and, in particular, labeling, privacy aspects, UDI assignment criteria, and international standards compliance. RESULTS: An approach for the management of each key point was suggested, resulting in different levels of implementation for UDI and traceability. CONCLUSIONS: Among the various types of medical devices, software is an increasingly large reality with very specific characteristics that must be taken into consideration. All the relevant aspects for the implementation of the UDI should be taken into consideration to combine safety and feasibility in order to effectively pursue the traceability of these medical devices.


Assuntos
Equipamentos e Provisões , Software , Equipamentos e Provisões/normas , Privacidade
4.
Curr Vasc Pharmacol ; 15(5): 482-490, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28155612

RESUMO

BACKGROUND: The literature shows that a healthy diet, rich in fruits and vegetables, has positive effects on overall cardiovascular risk, protecting against atherosclerosis. DESIGN: A cross sectional study in a population of apparently healthy young-adult men with the aim of investigating dietary determinants of early atherosclerosis, assessed by measuring carotid intima-media thickness (cIMT) and flow-mediated dilation (FMD) of the brachial artery. METHODS: 615 males (mean age ± SD: 40.8±9.8 years) without overt atherosclerosis were evaluated. Dietary intake was quantified by the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. Intake of antioxidants was expressed in relation to total caloric intake. RESULTS: Neither absolute, recommended daily allowance or weight-related values of nutritional intake variables were associated with cIMT. Vitamin E to total calories intake (odds ratio, OR=0.08, 95%CI=0.03-0.89) was inversely associated with impaired FMD. Non-nutritional correlates of FMD <10% were: age (OR=1.02, 95%CI=1.0-1.05) and waist circumference (OR=1.03, 95%CI=1.0-1.06), and those of cIMT >0.8 mm were age (OR=1.10, 95%CI=1.05-1.15), pack-years (OR=1.02, 95%CI=1.0-1.04), C-reactive protein (OR=1.17, 95%CI=1.04-1.33) and total cholesterol (OR=1.01, 95%CI=1.0-1.02). CONCLUSION: Differences in the factors correlating with cIMT >0.8 mm and FMD <10% might have implications for cardiovascular risk reduction. A lower antioxidant to caloric intake ratio might be a risk factor for impaired FMD.


Assuntos
Antioxidantes/administração & dosagem , Aterosclerose/prevenção & controle , Doenças Cardiovasculares/prevenção & controle , Dieta , Adulto , Fatores Etários , Artéria Braquial/metabolismo , Proteína C-Reativa/metabolismo , Espessura Intima-Media Carotídea , Estudos Transversais , Dieta Saudável , Ingestão de Energia/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários , Vitamina E/administração & dosagem , Circunferência da Cintura/fisiologia
5.
J Ultrasound Med ; 35(8): 1747-56, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27353068

RESUMO

OBJECTIVES: To evaluate carotid elasticity and left ventricular elastance during a graded bicycle semisupine exercise test in patients with known or suspected coronary artery disease and compare them with a control group of healthy young volunteers. METHODS: Thirty-six elderly patients and 18 young healthy volunteers were recruited. The right carotid diameter was estimated by an automatic system applied to B-mode sonographic sequences, central mean blood and pulse pressures by radial artery tonometry, and cardiac volumes by 2-dimensional transthoracic echocardiography; from these direct measurements, the carotid cross-sectional distensibility coefficient and left ventricular elastance index were obtained. Analyses were performed at rest, at peak stress, and during the recovery phase. RESULTS: The elderly patients included 20 men (mean age ± SD, 61 ± 8 years); the volunteers included 9 men (mean age, 34 ± 3 years). The mean blood pressure (at rest: patients, 97 ± 7 mm Hg; controls, 93 ± 9 mm Hg; not significant) increased similarly in both groups during exercise and decreased during the recovery phase. The diameter was higher in patients than controls (7.5 ± 1.1 versus 6.2 ± 0.5 mm) and increased significantly with exercise only in the latter group (at peak: 6.5 ± 0.6 mm; P < .05). The distensibility coefficient and elastance index were lower in patients than controls during the test phases [at rest: 24.5 ± 10.2 versus 60.8 ± 21.3 × 10(-3)/kPa and 3.6 ± 1.4 versus 1.6 ± 0.8 mm Hg/(mL/m(2))] and mostly changed in the controls, showing a decreased distensibility coefficient (peak: 40.6 ± 15.1 × 10(-3)/kPa) and an increased elastance index [peak: 5.9 ± 2.8 mm Hg/(mL/m(2))]. CONCLUSIONS: In older patients with multiple cardiovascular risk factors or established coronary artery disease, an abnormal carotid-ventricular adaptation to exercise was observed when compared to young healthy individuals.


Assuntos
Artérias Carótidas/fisiopatologia , Doença da Artéria Coronariana/fisiopatologia , Teste de Esforço , Exercício Físico/fisiologia , Ventrículos do Coração/fisiopatologia , Adulto , Pressão Sanguínea/fisiologia , Artérias Carótidas/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Ecocardiografia , Elasticidade/fisiologia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
6.
IEEE Trans Biomed Eng ; 63(4): 869-75, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26372116

RESUMO

OBJECTIVE: Central pulse pressure (cPP) is increasingly investigated as possible independent predictor of cardiovascular risk and carotid pulse pressure (carPP) can be used as a surrogate of cPP. Despite its importance, carPP measurement remains challenging in clinical practice. The aim of this study was to introduce a new easier-to-use method for noninvasive carPP evaluation based on the use of a MEMS accelerometer. METHODS: carPP values (carPP(acc)) were obtained in 22 subjects (10 males, 47 ±17 years, hypertension: 50%) postprocessing and double integrating the accelerometric signals. carPP(acc) measurements were compared with tonometric assessments (carPP(ton)), and ultrasound-derived measurements (carPP(us)). Moreover, accelerometric carotid pressure waveforms (P(acc)) were contrasted in terms of shape to those obtained by tonometry (P(ton)) and ultrasound images elaboration (P(US)), calculating the root mean square error (RMSE(ton), RMSE(US)) and the regression coefficients (r(ton) and r(US)). Moreover, both the repeatability and reproducibility analyses were performed. RESULTS: carPP(acc) values (45.9 ±10.6 mmHg) were significantly correlated with carPP(ton) (47.5 ±11.3 mmHg) and carPP(US) (43.3 ±8.4 mmHg) assessments (R = 0.94, p < 0.0001 and R = 0.80, p < 0.0001, respectively). The validity of the accelerometric approach was confirmed by morphological parameters ( RMSE(ton) = 5 ±1.95 mmHg, RMSE(US) = 5.5 ±2.3 mmHg, r(ton) = 0.94 ±0.04, r(US) = 0.93 ±0.04). Coefficient of variation (CV) was equal to 6.2% for the repeatability analysis, while CV values for interoperator and intersession reproducibilities were 8.9% and 9.4%, respectively. CONCLUSION: The proposed approach, providing an easier and more available measurement, could represent a valid alternative to existing and used technique for carPP assessment.


Assuntos
Acelerometria/métodos , Determinação da Pressão Arterial/métodos , Pressão Sanguínea/fisiologia , Artérias Carótidas/fisiologia , Processamento de Sinais Assistido por Computador/instrumentação , Acelerometria/instrumentação , Adulto , Determinação da Pressão Arterial/instrumentação , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Eur J Appl Physiol ; 114(7): 1503-12, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24728548

RESUMO

PURPOSE: Carotid pulse wave velocity (PWV) is considered as a surrogate marker for carotid stiffness and its assessment is increasingly being used in clinical practice. However, at the moment, its estimation needs specific equipment and a moderate level of technical expertise; moreover, it is based on a mathematical model. The aim of this study was to validate a new system for non-invasive and model-free carotid PWV assessment based on accelerometric sensors by comparison with currently used techniques. METHODS: Accelerometric PWV (accPWV) values were obtained in 97 volunteers free of cardiovascular disease (age 24-85 years) and compared with standard ultrasound-based carotid stiffness parameters, such as carotid PWV (cPWV), relative distension (relD) and distensibility coefficient (DC). Moreover, the comparison between accPWV measurements and carotid-femoral PWV (cfPWV) was performed. RESULTS: Accelerometric PWV evaluations showed a significant correlation with cPWV measurements (R = 0.67), relD values (R = 0.66) and DC assessments (R = 0.64). These values were also significantly correlated with cfPWV evaluations (R = 0.46). In addition, the first attempt success rate was equal to 76.8 %. CONCLUSIONS: The accelerometric system allows a simple and quick local carotid stiffness evaluation and the values obtained with this system are significantly correlated with known carotid stiffness biomarkers. Therefore, the presented device could provide a concrete opportunity for an easy carotid stiffness evaluation even in clinical practice.


Assuntos
Acelerometria/instrumentação , Artérias Carótidas/fisiologia , Análise de Onda de Pulso/instrumentação , Transdutores , Rigidez Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas/diagnóstico por imagem , Desenho de Equipamento , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Ultrassonografia , Adulto Jovem
8.
Curr Pharm Des ; 19(13): 2390-400, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23173588

RESUMO

Ultrasound assessment of vascular biomarkers has been implemented for screening, prevention and improvement of cardiovascular risk stratification beyond classical risk factors including smoking, diabetes, hypercholesterolemia and hypertension. Thus, the presence of vascular damage at the sub-clinical, asymptomatic stages can identify a "vulnerable" patient, and aid in implementing cardiovascular prevention strategies. Increased intima-media thickness of the common carotid artery is a well-known marker of early atherosclerosis, which significantly correlates with the development of coronary or cerebro-vascular disease. More recently, guidelines for cardiovascular prevention in hypertension also introduced other vascular parameters evaluating both mechanical and functional arterial properties of peripheral arteries. Increased arterial stiffness, which can be detected by ultrasound at the common carotid, has been shown to predict future cardiovascular events and it is already considered a subclinical target organ of hypertensive patients. Even earlier vascular abnormalities such as endothelial dysfunction in the peripheral arteries, detected as reduced flow-mediated dilation of the brachial artery by ultrasound, have also been mentioned for their possible clinical use in the future. This manuscript reviews clinical evidence supporting the use of these different vascular markers for cardiovascular risk stratification, focusing on the need for an accurate, robust and reliable methodology for the assessment of vascular markers, which could improve their predictive value and increase their use in routine clinical practice.


Assuntos
Artérias Carótidas/anatomia & histologia , Artérias Carótidas/fisiologia , Humanos , Prognóstico , Túnica Íntima/fisiologia
9.
Atherosclerosis ; 223(2): 372-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22727194

RESUMO

OBJECTIVE: To evaluate local carotid stiffness (CS) and intima-medial thickness (C-IMT) in hypertensive patients with different cardiovascular risk profile, using a new user-friendly ultrasound-based system, previously validated vs. RF-based echotracking device. METHODS: We investigated a population with different cardiovascular risk: 45 healthy normotensives (NT), 90 non-diabetic hypertensives (HT), and 48 patients with hypertension and type-2 diabetes (DM). Framingham risk factor score (FRS) was calculated. PWV was assessed by applanation tonometry. The relative stroke change in diameter (ΔD) and C-IMT were measured on carotid scans. Distensibility coefficient (DC) was calculated as ΔA/(A*ΔP), where A = diastolic lumen area, ΔA = stroke change in lumen area, and ΔP = carotid pulse pressure. CS (m/s) was calculated as (ρ*DC) - 1/2 (ρ = blood density). RESULTS: CS, C-IMT, PWV were significantly increased in HT and DM vs. NT. C-IMT and PWV were significantly higher in DM than HT. ΔD and DC were significantly lower in HT and DM vs. NT. FRS ≥10% group showed increased carotid diameter, C-IMT and CS than the FRS <10%. FRS was (p < 0.001) correlated with CS (r = 0.35); ΔD (r = -0.36), DC (r = 0.35), C-IMT (r = 0.48), PWV (r = 0.38). CS correlated (p < 0.05) with PWV in the entire population (r = 0.37), in the NT (r = 0.35), in the HT and DM (r = 0.20). PWV (r = 0.50) and CS (r = 0.33) were correlated with age. Determinants of aortic and carotid stiffness were identified by multivariate stepwise analysis. CONCLUSIONS: The proposed B-mode ultrasound-based system is a reliable and user-friendly method that could serve to investigate the predictive value of CS for cardiovascular events in future large clinical studies.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Hipertensão/diagnóstico por imagem , Rigidez Vascular , Adulto , Idoso , Artérias Carótidas/fisiopatologia , Doenças das Artérias Carótidas/epidemiologia , Doenças das Artérias Carótidas/fisiopatologia , Distribuição de Qui-Quadrado , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Hemodinâmica , Humanos , Hipertensão/epidemiologia , Hipertensão/fisiopatologia , Itália/epidemiologia , Modelos Lineares , Masculino , Manometria , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Análise de Onda de Pulso , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco
10.
J Hypertens ; 30(7): 1399-405, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22525207

RESUMO

OBJECTIVE: Impaired flow-mediated dilation (FMD) is associated with cardiovascular risk factors and provides prognostic information. Despite the noninvasive nature of this technique, a major limitation to its widespread use is low reproducibility. The aim of this study was to evaluate impact of methodological standardization among different investigation sites on brachial artery FMD reproducibility. METHODS: Seven Italian centers recruited 135 healthy volunteers, aged 20-60 years. FMD was assessed by high-resolution ultrasound equipped with a stereotactic probe-holding device. Certified sonographers recorded brachial artery scans at baseline (day 1a), 1 h after (day 1b), and 1 month later (day 30). Endothelium-independent vasodilation (EIVD) to sublingual glyceril-trinitrate was recorded at day 1 and day 30. FMD and EIVD were blindly evaluated at the coordinating center by an automated edge detection system. The intra-session (day 1a versus 1b) and inter-session (day 1a versus 30) coefficients of variation were calculated. RESULTS: FMD was not significantly (P = 0.91) different at day 1a, day 1b and day 30 (6.52 ± 2.9, 6.42 ± 3.1, 6.57 ± 2.8%, respectively). The FMD intra-session coefficient of variation was 9.9 ± 8.4% (from 7.6 to 11.9% across centers). The FMD inter-session coefficient of variation was 12.9 ± 11.6% (from 11.6 to 16.1% across centers). Inter-session coefficient of variation for EIDV was 19.7 ± 16.8%. CONCLUSIONS: This study shows a homogeneous coefficient of variation for FMD among different centers. The inter-session coefficient of variation was similar to the intra-session coefficient of variation, representing the intrinsic FMD variability. We demonstrate for the first time that rigorous and standardized procedure may provide reproducible FMD assessment to study endothelial function in multicenter clinical trials.


Assuntos
Vasodilatação , Adulto , Feminino , Humanos , Itália , Masculino , Valores de Referência , Reprodutibilidade dos Testes
11.
Ultrasound Med Biol ; 38(2): 223-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22178161

RESUMO

The study aimed to evaluate the reproducibility of carotid elasticity during exercise. Eighteen healthy volunteers (nine males, age 34 ± 3 years, BMI 22 ± 6 kg/m(2)) underwent maximal exercise testing on a graded semi-supine cycle ergometer in two different sessions 3 days apart. Ultrasound B-mode image sequences of the right common carotid were acquired at different steps and analyzed by an automatic system; pressures were estimated by tonometry. Compliance (CC) and distensibility (DC) were significantly decreased at exercise peak and in the first recovery minute (CC from 1.6 ± 0.8 to 1 ± 0.6 mm^(2)/KPa, DC from 56.2 ± 25.3 to 34.5 ± 20 10^(-3)/KPa, p < 0.05). For the whole examination, intraclass coefficient was 0.780 for CC and 0.694 for DC. Mean coefficient of variation was maximum at peak exercise (CC = 19 ± 6%, DC = 24 ± 15%), but at first minute of recovery it was comparable to resting values (CC = 12 ± 9%, DC = 12 ± 11%). When designing future studies, acquisitions during first recovery minute might be preferred to peak measures.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/fisiopatologia , Técnicas de Imagem por Elasticidade/métodos , Esforço Físico/fisiologia , Adulto , Módulo de Elasticidade , Teste de Esforço , Feminino , Humanos , Masculino , Resistência Vascular/fisiologia
12.
J Hypertens ; 29(1): 85-90, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20842049

RESUMO

OBJECTIVES: Brachial artery flow-mediated dilation (FMD) is associated with risk factors providing information on cardiovascular prognosis. Despite the large effort to standardize the methodology, the FMD examination is still characterized by problems of reproducibility and reliability that can be partially overcome with the use of automatic systems. We developed real-time software for the assessment of brachial FMD (FMD Studio, Institute of Clinical Physiology, Pisa, Italy) from ultrasound images. The aim of this study is to compare our system with another automatic method (Brachial Analyzer, MIA LLC, IA, USA) which is currently considered as a reference method in FMD assessment. METHODS: The agreement between systems was assessed as follows. Protocol 1: Mean baseline (Basal), maximal (Max) brachial artery diameter after forearm ischemia and FMD, calculated as maximal percentage diameter increase, have been evaluated in 60 recorded FMD sequences. Protocol 2: Values of diameter and FMD have been evaluated in 618 frames extracted from 12 sequences. RESULTS: All biases are negligible and standard deviations of the differences are satisfactory (protocol 1: -0.27 ± 0.59%; protocol 2: -0.26 ± 0.61%) for FMD measurements. Analysis times were reduced (-33%) when FMD Studio is used. Rejected examinations due to the poor quality were 2% with the FMD Studio and 5% with the Brachial Analyzer. CONCLUSIONS: In conclusion, the compared systems show a optimal grade of agreement and they can be used interchangeably. Thus, the use of a system characterized by real-time functionalities could represent a referral method for assessing endothelial function in clinical trials.


Assuntos
Automação , Artéria Braquial/fisiologia , Dilatação Patológica , Fluxo Sanguíneo Regional , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
13.
J Ultrasound Med ; 29(8): 1169-75, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20660450

RESUMO

OBJECTIVE: Increased arterial stiffness and carotid intima-media thickness (IMT) are considered independent predictors of cardiovascular events. The aim of this study was to compare a system recently developed in our laboratory for automatic assessment of these parameters from ultrasound image sequences to a reference radio frequency (RF) echo-tracking system. METHODS: Common carotid artery scans of 21 patients with cardiovascular risk factors and 12 healthy volunteers were analyzed by both devices for the assessment of diameter (D), IMT, and distension (DeltaD). In the healthy volunteers, analyses were repeated twice to evaluate intraobserver variability. Agreement was evaluated by Bland-Altman analysis, whereas reproducibility was expressed as a coefficient of variation (CV). RESULTS: Regarding the agreement between the two systems, bias values +/- SD were 0.060 +/- 0.110 mm for D, -0.006 +/- 0.039 mm for IMT, and -0.016 +/- 0.039 mm for DeltaD. Intraobserver CVs were 2% +/- 2% for D, 5% +/- 5% for IMT, and 6% +/- 6% for DeltaD with the RF echo-tracking system and 2% +/- 1% for D, 6% +/- 6% for IMT, and 8% +/- 6% for DeltaD with our automated system. CONCLUSIONS: Although B-mode-based devices are less precise than RF-based ones, our automated system has good agreement with the reference method and comparable reproducibility, at least when high-quality images are analyzed. Hence, this study suggests that the presented system based on image processing from standard ultrasound scans is a suitable device for measuring IMT and local arterial stiffness parameters in clinical studies.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/fisiologia , Técnicas de Imagem por Elasticidade/métodos , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/fisiologia , Túnica Média/diagnóstico por imagem , Túnica Média/fisiologia , Adolescente , Módulo de Elasticidade/fisiologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Pacing Clin Electrophysiol ; 33(7): 795-803, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20132499

RESUMO

BACKGROUND: Invasively measured left ventricular (LV) dP/dt is the accepted standard for measuring acute and chronic directional changes in LV contractility. Recently, we developed a noninvasive force sensor based on an accelerometer positioned on the chest, which measures the vibrations generated by isovolumic myocardial contraction. The aim of this paper was to compare noninvasive (accelerometer) versus invasive (LV dP/dt) indices of myocardial contractility in a chronic minipig model of pacing-induced heart failure (HF). Comparative assessment was performed both at rest and following dobutamine infusion. METHODS: In adult male minipigs (n = 6), LV contractility was simultaneously assessed both invasively (LV dP/dt, Millar catheter) and noninvasively (accelerometer) at rest and following dobutamine (up to 7.5 mcg/kg/min), both before and after development of HF by pacing the LV at 180 beats/min for 3 weeks. RESULTS: Invasive and noninvasive assessments were obtained in 24 conditions (12 at rest and 12 after dobutamine infusion). Sensor-based cardiac force changes were significantly related to positive peak LV dP/dt(max) changes following dobutamine infusion both in normal (r = 0.88, P < 0.001) and failing heart (r = 0.89, P < 0.001). The force-frequency relation showed a tight correlation between invasive and noninvasive assessment (r = 0.68, P = 0.02). CONCLUSIONS: The force-frequency relation can be assessed noninvasively by a transthoracic sensor based on an accelerometer. The method can efficiently detect the development of resting dysfunction and the contractile reserve at different HF steps, with potential for wearable HF monitoring.


Assuntos
Aceleração , Insuficiência Cardíaca/fisiopatologia , Testes de Função Cardíaca/instrumentação , Contração Miocárdica , Transdutores , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos , Porco Miniatura , Disfunção Ventricular Esquerda/complicações , Vibração
15.
Cardiovasc Ultrasound ; 7: 21, 2009 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-19442285

RESUMO

BACKGROUND: New sensors for intelligent remote monitoring of the heart should be developed. Recently, a cutaneous force-frequency relation recording system has been validated based on heart sound amplitude and timing variations at increasing heart rates. AIM: To assess sensor-based post-exercise contractility, diastolic function and pressure in normal and diseased hearts as a model of a wireless telemedicine system. METHODS: We enrolled 150 patients and 22 controls referred for exercise-stress echocardiography, age 55 +/- 18 years. The sensor was attached in the precordial region by an ECG electrode. Stress and recovery contractility were derived by first heart sound amplitude vibration changes; diastolic times were acquired continuously. Systemic pressure changes were quantitatively documented by second heart sound recording. RESULTS: Interpretable sensor recordings were obtained in all patients (feasibility = 100%). Post-exercise contractility overshoot (defined as increase > 10% of recovery contractility vs exercise value) was more frequent in patients than controls (27% vs 8%, p < 0.05). At 100 bpm stress heart rate, systolic/diastolic time ratio (normal, < 1) was > 1 in 20 patients and in none of the controls (p < 0.01); at recovery systolic/diastolic ratio was > 1 in only 3 patients (p < 0.01 vs stress). Post-exercise reduced arterial pressure was sensed. CONCLUSION: Post-exercise contractility, diastolic time and pressure changes can be continuously measured by a cutaneous sensor. Heart disease affects not only exercise systolic performance, but also post-exercise recovery, diastolic time intervals and blood pressure changes--in our study, all of these were monitored by a non-invasive wearable sensor.


Assuntos
Determinação da Pressão Arterial/métodos , Pressão Sanguínea , Diagnóstico por Computador/métodos , Auscultação Cardíaca/métodos , Contração Miocárdica , Telemedicina/métodos , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Aceleração , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse Mecânico
16.
Cardiovasc Ultrasound ; 6: 41, 2008 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-18715514

RESUMO

BACKGROUND: Recently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2) amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations at increasing heart rates and hemodynamic changes. METHODS: The transcutaneous force sensor was positioned in the precordial region in 146 consecutive patients referred for exercise (n = 99), dipyridamole (n = 41), or pacing stress (n = 6). The curve of S2 peak amplitude variation as a function of heart rate was computed as the increment with respect to the resting value. RESULTS: A consistent S2 signal was obtained in all patients. Baseline S2 was 7.2 +/- 3.3 mg, increasing to 12.7 +/- 7.7 mg at peak stress. S2 percentage increase was + 133 +/- 104% in the 99 exercise, + 2 +/- 22% in the 41 dipyridamole, and + 31 +/- 27% in the 6 pacing patients (p < 0.05). Significant determinants of S2 amplitude were blood pressure, heart rate, and cardiac index with best correlation (R = .57) for mean pressure. CONCLUSION: S2 recording quantitatively documents systemic pressure changes.


Assuntos
Monitores de Pressão Arterial , Pressão Sanguínea , Ecocardiografia sob Estresse , Ruídos Cardíacos , Idoso , Ciclismo , Estimulação Cardíaca Artificial , Dipiridamol , Eletrocardiografia , Feminino , Coração/fisiopatologia , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico , Decúbito Dorsal , Resistência Vascular
17.
J Ultrasound Med ; 27(9): 1353-61, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18716145

RESUMO

OBJECTIVE: The purpose of this report is to describe an automatic real-time system for evaluation of the carotid intima-media thickness (CIMT) characterized by 3 main features: minimal interobserver and intraobserver variability, real-time capabilities, and great robustness against noise. METHODS: One hundred fifty carotid B-mode ultrasound images were used to validate the system. Two skilled operators were involved in the analysis. Agreement with the gold standard, defined as the mean of 2 manual measurements of a skilled operator, and the interobserver and intraobserver variability were quantitatively evaluated by regression analysis and Bland-Altman statistics. RESULTS: The automatic measure of the CIMT showed a mean bias +/- SD of 0.001 +/- 0.035 mm toward the manual measurement. The intraobserver variability, evaluated with Bland-Altman plots, showed a bias that was not significantly different from 0, whereas the SD of the differences was greater in the manual analysis (0.038 mm) than in the automatic analysis (0.006 mm). For interobserver variability, the automatic measurement had a bias that was not significantly different from 0, with a satisfactory SD of the differences (0.01 mm), whereas in the manual measurement, a little bias was present (0.012 mm), and the SD of the differences was noticeably greater (0.044 mm). CONCLUSIONS: The CIMT has been accepted as a noninvasive marker of early vascular alteration. At present, the manual approach is largely used to estimate CIMT values. However, that method is highly operator dependent and time-consuming. For these reasons, we developed a new system for the CIMT measurement that conjugates precision with real-time analysis, thus providing considerable advantages in clinical practice.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Idoso , Sistemas Computacionais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência
18.
Cardiovasc Ultrasound ; 6: 15, 2008 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-18426559

RESUMO

UNLABELLED: A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration. AIMS: 1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress. METHODS: We enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients).The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal. Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time. RESULTS: Diastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 +/- 0.12) than in patients (0.86 +/- 0.10, p < 0.05 vs. controls). Diastolic filling rate increased from 101 +/- 36 (rest) to 219 +/- 92 ml/m2* s-1 at peak stress (p < 0.5 vs. rest). CONCLUSION: Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate.Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.


Assuntos
Circulação Coronária , Diástole , Auscultação Cardíaca/métodos , Modelos Cardiovasculares , Volume Sistólico , Disfunção Ventricular Esquerda/fisiopatologia , Simulação por Computador , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatística como Assunto
19.
Ultrasound Med Biol ; 34(3): 385-91, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17964069

RESUMO

The methods commonly used for noninvasive ultrasound assessment of endothelium-dependent flow-mediated dilation (FMD) require an electrocardiogram (ECG) signal to synchronize the measurements with the cardiac cycle. In this article, we present a method for assessing FMD that does not require ECG gating. The approach is based on temporal filtering of the diameter-time curve, which is obtained by means of a B-mode image processing system. The method was tested on 22 healthy volunteers without cardiovascular risk factors. The measurements obtained with the proposed approach were compared with those obtained with ECG gating and with both systolic and end-diastolic measurements. Results showed good agreement between the methods and a higher precision of the new method due to the fact that it is based on a larger number of measurements. Further advantages were also found both in terms of reliability of the measure and simplification of the instrumentation. (E-mail: gemi@ifc.cnr.it).


Assuntos
Artéria Braquial/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador , Vasodilatação/fisiologia , Adulto , Eletrocardiografia , Feminino , Humanos , Masculino , Fluxo Sanguíneo Regional/fisiologia , Ultrassonografia
20.
Cardiovasc Ultrasound ; 5: 42, 2007 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-18031588

RESUMO

BACKGROUND: The inherent ability of ventricular myocardium to increase its force of contraction in response to an increase in contraction frequency is known as the cardiac force-frequency relation (FFR). This relation can be easily obtained in the stress echo lab, where the force is computed as the systolic pressure/end-systolic volume index ratio, and measured for increasing heart rates during stress. Ideally, the noninvasive, imaging independent, objective assessment of FFR would greatly enhance its practical appeal. OBJECTIVES: 1 - To evaluate the feasibility of the cardiac force measurement by a precordial cutaneous sensor. 2 - To build the curve of force variation as a function of the heart rate. 3 - To compare the standard stress echo results vs. this sensor operator-independent built FFR. METHODS: The transcutaneous force sensor was positioned in the precordial region in 88 consecutive patients referred for exercise, dipyridamole, or pacing stress. The force was measured as the myocardial vibrations amplitude in the isovolumic contraction period. FFR was computed as the curve of force variation as a function of heart rate. Standard echocardiographic FFR measurements were performed. RESULTS: A consistent FFR was obtained in all patients. Both the sensor built and the echo built FFR identifiy pts with normal or abnormal contractile reserve. The best cut-off value of the sensor built FFR was 15.5 g * 10-3 (Sensitivity = 0.85, Specificity = 0.77). Sensor built FFR slope and shape mirror pressure/volume relation during stress. This approach is extendable to daily physiological exercise and could be potentially attractive in home monitoring systems.


Assuntos
Ecocardiografia sob Estresse , Cardiopatias/fisiopatologia , Interpretação de Imagem Assistida por Computador/métodos , Contração Miocárdica/fisiologia , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Pressão Sanguínea/fisiologia , Estimulação Cardíaca Artificial , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/fisiopatologia , Teste de Esforço/métodos , Estudos de Viabilidade , Feminino , Cardiopatias/diagnóstico por imagem , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Interpretação de Imagem Assistida por Computador/instrumentação , Masculino , Pessoa de Meia-Idade , Volume Sistólico
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