RESUMO
Despite different developmental and pathological processes affecting lung vascular remodeling in both patient populations, differences in 4D MRI findings between children and adults with PAH have not been studied. The purpose of this study was to compare flow hemodynamic state, including flow-mediated shear forces, between pediatric and adult patients with PAH matched by severity of pulmonary vascular resistance index (PVRi). Adults (n = 10) and children (n = 10) with PAH matched by pulmonary vascular resistance index (PVRi) and healthy adult (n = 10) and pediatric (n = 10) subjects underwent comprehensive 4D-flow MRI to assess peak systolic wall shear stress (WSSmax) measured in the main (MPA), right (RPA), and left pulmonary arteries (LPA), viscous energy loss (EL) along the MPA-RPA and MPA-LPA tract, and qualitative analysis of secondary flow hemodynamics. WSSmax was decreased in all pulmonary vessels in children with PAH when compared with the same age group (all P < 0.05). Similarly, WSSmax was decreased in all pulmonary vessels in adult PAH patients when compared with healthy adult subjects (all P < 0.01). Average EL was increased in adult patients with PAH when compared with the same age group along both MPA-RPA (P = 0.020) and MPA-LPA (P = 0.025) tracts. There were no differences in EL indices between adults and pediatric patients. Children and adult patients with PAH have decreased shear hemodynamic forces. However, pathological flow hemodynamic formations appear to be more consistent in adult patients, whereas flow hemodynamic abnormalities appear to be more variable in children with PAH for comparable severity of PVRi. NEW & NOTEWORTHY Both children and adult patients with PAH have decreased shear hemodynamic forces inside the pulmonary arteries associated with the degree of vessel dilation and stiffness. These differences also exist between healthy normotensive children and adults. However, pathological flow hemodynamic formations appear to more uniform in adult patients, whereas in children with PAH flow, hemodynamic abnormalities appear to be more variable. Pathological flow formations appear not to have a major effect on viscous energy loss associated with the flow conduction through proximal pulmonary arteries.
Assuntos
Pressão Arterial , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão/métodos , Hipertensão Arterial Pulmonar/diagnóstico por imagem , Artéria Pulmonar/diagnóstico por imagem , Circulação Pulmonar , Adolescente , Fatores Etários , Idoso , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Hipertensão Arterial Pulmonar/fisiopatologia , Artéria Pulmonar/fisiopatologia , Índice de Gravidade de Doença , Estresse Mecânico , Resistência VascularRESUMO
OBJECTIVE: Central aortic stiffness and chronic obstructive pulmonary disease (COPD) are associated with increased incidence of devastating aortopathies. However, the exact mechanism leading to elevated aortic stiffness in patients with COPD is unknown. The purpose of this study was to quantify flow and shear hemodynamic indices, known markers of vascular remodeling, in the thoracic aorta of patients with mild to moderate COPD (n = 16) and to compare these results with an age-matched control group (n = 10). METHODS: Four-dimensional flow magnetic resonance imaging has been applied to measure hemodynamic wall shear stress (WSS) at four specific planes along the ascending aorta, aortic arch, and proximal descending aorta for all subjects. Peak systolic WSS and time-averaged WSS, which respectively reflect magnitude and temporal shear variability, were calculated at standardized planes. Aortic deformation was measured by means of relative area change (RAC) at the midlevel of the ascending and descending aorta. RESULTS: Compared with controls, patients with COPD had significantly reduced RAC in the mid ascending aorta (9% vs 18%; P < .0001) and descending aorta (15% vs 19%; P = .0206). Peak systolic WSS in COPD patients was significantly reduced in all considered planes, with the most dramatic difference occurring in the descending aorta (0.46 vs 0.86 N/m2; P < .0001). Peak systolic WSS and time-averaged WSS were both significantly correlated with aortic RAC at each evaluated plane. CONCLUSIONS: Reduced flow shear metrics assessed at specific aortic regions correlated with RAC, a marker of aortic stiffness. Reduced hemodynamic WSS may then contribute to central aortic stiffening and perpetuate the risk for development of severe aortopathy.
Assuntos
Aorta Torácica/fisiopatologia , Doenças da Aorta/etiologia , Hemodinâmica , Doença Pulmonar Obstrutiva Crônica/complicações , Rigidez Vascular , Idoso , Aorta Torácica/diagnóstico por imagem , Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/fisiopatologia , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Angiografia por Ressonância Magnética , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Cardiovasculares , Modelagem Computacional Específica para o Paciente , Imagem de Perfusão/métodos , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Fluxo Sanguíneo Regional , Fatores de Risco , Estresse MecânicoRESUMO
PURPOSE: To develop an estimate of pulmonary vascular resistance (PVR) using blood flow measurements from 3D velocity-encoded phase contract magnetic resonance imaging (here termed 4D MRI). MATERIALS AND METHODS: In all, 17 patients with pulmonary hypertension (PH) and five controls underwent right heart catheterization (RHC), 4D and 2D Cine MRI (1.5T) within 24 hours. MRI was used to compute maximum spatial peak systolic vorticity in the main pulmonary artery (MPA) and right pulmonary artery (RPA), cardiac output, and relative area change in the MPA. These parameters were combined in a four-parameter multivariate linear regression model to arrive at an estimate of PVR. Agreement between model predicted and measured PVR was also evaluated using Bland-Altman plots. Finally, model accuracy was tested by randomly withholding a patient from regression analysis and using them to validate the multivariate equation. RESULTS: A decrease in vorticity in the MPA and RPA were correlated with an increase in PVR (MPA: R(2) = 0.54, P < 0.05; RPA: R(2) = 0.75, P < 0.05). Expanding on this finding, we identified a multivariate regression equation that accurately estimates PVR (R(2) = 0.94, P < 0.05) across severe PH and normotensive populations. Bland-Altman plots showed 95% of the differences between predicted and measured PVR to lie within 1.49 Wood units. Model accuracy testing revealed a prediction error of â¼20%. CONCLUSION: A multivariate model that includes MPA relative area change and flow characteristics, measured using 4D and 2D Cine MRI, offers a promising technique for noninvasively estimating PVR in PH patients. J. MAGN. RESON. IMAGING 2016;44:914-922.
Assuntos
Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/fisiopatologia , Angiografia por Ressonância Magnética/métodos , Imagem Cinética por Ressonância Magnética/métodos , Artéria Pulmonar/fisiopatologia , Circulação Pulmonar , Resistência Vascular , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Artéria Pulmonar/diagnóstico por imagem , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The response of the right ventricle (RV) to pulmonary arterial hypertension (PAH) involves changes in contractile function, chamber size, hypertrophy, and extracellular matrix (ECM). Galectin-3 (Gal-3) is a mediator of myocardial ECM metabolism and biomarker for left heart remodeling, yet its ability to reflect RV remodeling is unknown. We hypothesized that serum Gal-3 levels correlate with RV morphology and function in PAH, and that Gal-3 is associated with circulating markers of ECM. Fifteen subjects with PAH and 10 age-matched controls underwent same-day echocardiography, cardiac magnetic resonance (CMR) imaging, and phlebotomy for Gal-3 and ECM biomarkers including N-terminal propeptide of type III collagen type (PIIINP), tissue inhibitor of metalloproteinase-1 (TIMP-1), and hyaluronic acid (HA). RV ejection fraction, end diastolic volume index, end systolic volume index, and mass index were calculated using CMR. Echocardiography was used to estimate RV systolic pressure and measure RV strain. Serum Gal-3, TIMP-1, and HA levels were all significantly increased in PAH subjects when compared to controls. Gal-3 correlated with RV ejection fraction (ρ -0.44, p 0.03), end diastolic volume index (ρ 0.42, p 0.03), end systolic volume index (ρ 0.44, p 0.027), mass index (ρ 0.47, p 0.016), systolic pressure (ρ 0.55, p < 0.001), and strain (ρ 0.43, p 0.03). Gal-3 levels positively correlated with the ECM markers TIMP-1 and HA but not with PIIINP. In conclusion, Gal-3 levels are associated with multiple indices of RV function and morphology. Gal-3 may represent a novel biomarker for RV remodeling and associated ECM turnover in PAH.
Assuntos
Galectina 3/sangue , Hipertensão Pulmonar/sangue , Hipertrofia Ventricular Direita/sangue , Disfunção Ventricular Direita/sangue , Função Ventricular Direita , Remodelação Ventricular , Idoso , Biomarcadores/sangue , Proteínas Sanguíneas , Ecocardiografia Doppler de Pulso , Fibrose , Galectinas , Humanos , Ácido Hialurônico/sangue , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/diagnóstico , Hipertrofia Ventricular Direita/etiologia , Hipertrofia Ventricular Direita/fisiopatologia , Imagem Cinética por Ressonância Magnética , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Fragmentos de Peptídeos/sangue , Projetos Piloto , Valor Preditivo dos Testes , Pró-Colágeno/sangue , Estudos Prospectivos , Inibidor Tecidual de Metaloproteinase-1/sangue , Regulação para Cima , Disfunção Ventricular Direita/diagnóstico , Disfunção Ventricular Direita/etiologia , Disfunção Ventricular Direita/fisiopatologia , Pressão VentricularRESUMO
Right ventricular diastolic dysfunction (RVDD) is an important prognostic indicator in pulmonary arterial hypertension (PAH). RV vortex rings have been observed in healthy subjects, but their significance in RVDD is unknown. Vorticity, the local spinning motion of an element of fluid, may be a sensitive measure of RV vortex dynamics. Using four-dimensional (4D) flow cardiac magnetic resonance imaging (CMR), we investigated the relationship between right heart vorticity with echocardiographic indexes of RVDD. Thirteen (13) PAH subjects and 10 controls underwent same-day 4D flow CMR and echocardiography. RV diastolic function was assessed using trans-tricuspid valve (TV) early (E) and late (A) velocities, E/A ratio, and e' and a' tissue Doppler velocities. RV and right atrial (RA) integrated mean vorticity was calculated for E and A-wave filling periods using 4D datasets. Compared with controls, A-wave vorticity was significantly increased in RVDD subjects in both the RV [2343 (1,559-3,295) vs. 492 (267-2,649) 1/s, P = 0.028] and RA [30 (27-44) vs. 9 (5-27) 1/s, P = 0.005]. RA E vorticity was significantly decreased [13 (7-22) vs. 28 (15-31) 1/s, P = 0.038] in RVDD. E-wave vorticity correlated TV e', E-,and TV E/A (P < 0.05), and A-wave vorticity associated with both TV A and E/A (P < 0.02). RVDD is associated with alterations in E- and A-wave vorticity, and vorticity correlates with multiple echocardiographic markers of RVDD. Vorticity may be a robust noninvasive research tool for the investigation of RV fluid and tissue mechanical interactions in PAH.
Assuntos
Diástole , Hemodinâmica , Hipertensão Pulmonar/diagnóstico por imagem , Disfunção Ventricular Direita/diagnóstico por imagem , Idoso , Estudos de Casos e Controles , Ecocardiografia , Ecocardiografia Doppler , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Hidrodinâmica , Hipertensão Pulmonar/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Estudos Prospectivos , Disfunção Ventricular Direita/fisiopatologiaRESUMO
BACKGROUND: Cost-utility models are frequently used to compare treatments intended to prevent or delay the onset of cardiovascular events. Most published utilities represent post-event health states without incorporating the disutility of the event or reporting the time between the event and utility assessment. Therefore, this study estimated health state utilities representing cardiovascular conditions while distinguishing between acute impact including the cardiovascular event and the chronic post-event impact. METHODS: Health states were drafted and refined based on literature review, clinician interviews, and a pilot study. Three cardiovascular conditions were described: stroke, acute coronary syndrome (ACS), and heart failure. One-year acute health states represented the event and its immediate impact, and post-event health states represented chronic impact. UK general population respondents valued the health states in time trade-off tasks with time horizons of one year for acute states and ten years for chronic states. RESULTS: A total of 200 participants completed interviews (55% female; mean age = 46.6 y). Among acute health states, stroke had the lowest utility (0.33), followed by heart failure (0.60) and ACS (0.67). Utility scores for chronic health states followed the same pattern: stroke (0.52), heart failure (0.57), and ACS (0.82). For stroke and ACS, acute utilities were significantly lower than chronic post-event utilities (difference = 0.20 and 0.15, respectively; both p < 0.0001). CONCLUSIONS: Results add to previously published utilities for cardiovascular events by distinguishing between chronic post-event health states and acute health states that include the event and its immediate impact. Findings suggest that acute versus chronic impact should be considered when selecting scores for use in cost-utility models. Thus, the current utilities provide a unique option that may be used to represent the acute and chronic impact of cardiovascular conditions in economic models comparing treatments that may delay or prevent the onset of cardiovascular events.
Assuntos
Síndrome Coronariana Aguda , Nível de Saúde , Insuficiência Cardíaca , Qualidade de Vida , Acidente Vascular Cerebral , Síndrome Coronariana Aguda/economia , Adulto , Idoso , Doença Crônica , Feminino , Insuficiência Cardíaca/economia , Humanos , Entrevistas como Assunto , Londres , Masculino , Pessoa de Meia-Idade , Modelos Econômicos , Projetos Piloto , Pesquisa Qualitativa , Escócia , Acidente Vascular Cerebral/economia , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVE: Cystatin C (CysC), a novel marker of renal function, predicts left heart failure and cardiovascular mortality. The hypothesis that serum CysC levels correlate with right ventricular (RV) morphology, function and pressure in pulmonary arterial hypertension (PAH) was tested. METHODS: As part of a prospective study, 14 PAH subjects and 10 matched controls underwent same-day echocardiography, cardiac magnetic resonance imaging (CMR), and phlebotomy for CysC, brain natriuretic peptide (BNP), and N-terminal BNP (NT-ProBNP). RV ejection fraction (RVEF), end-diastolic volume, end-systolic volume and mass were calculated using CMR. RV systolic pressure (RVSP), strain and diastolic function (including tricuspid valve (TV) E velocity, A velocity, e' velocity, E/A ratio and E/e' ratio) were assessed using echocardiography. RESULTS: RVSP was significantly elevated in PAH subjects versus controls (57 ± 17 vs. 28 ± 8 mm Hg, P < 0.0001). CysC was abnormally elevated in the PAH cohort when compared with controls (1.00 ± 0.23 vs 0.78 ± 0.05 mg/L, P = 0.001). CysC positively correlated with RVSP (rho 0.61, P = 0.002), RV end-diastolic volume (rho 0.50, P = 0.01), RV end-systolic volume (rho 0.58, P = 0.003), mass index (rho 0.66, P = 0.0004), strain (rho 0.51, P = 0.01) and strain rate (rho 0.51, P = 0.01) and negatively correlated with RVEF (rho -0.58, P = 0.003) and TV e' (rho -0.75, P < 0.0001). The same correlations with BNP and NT-ProBNP were comparable with CysC. CONCLUSIONS: In a small cohort, CysC accurately correlates with RV pressure, function and morphology. CysC may represent a novel PAH biomarker.
Assuntos
Cistatina C/sangue , Hipertensão Pulmonar , Volume Sistólico , Função Ventricular Direita , Biomarcadores/sangue , Feminino , Humanos , Hipertensão Pulmonar/sangue , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Projetos Piloto , Circulação Pulmonar , Reprodutibilidade dos Testes , Estatística como AssuntoRESUMO
Although the "3 beat rule" is widely utiized to discriminate patent foramen ovale (PFO)-mediated right-to-left shunt (RTLS) from intrapulmonary RTLS using saline contrast transthoracic echocardiography (SCE), SCE diagnostic performance has yet to be validated using an invasive intracardiac standard. Percutaneous PFO occluder placement was recently shown to ameliorate hypoxia in patients with suspected PFO-mediated RTLS. We evaluated the ability of SCE to predict PFO presence and size using intracardiac echocardiography (ICE) as a gold standard in a hypoxic cohort. Sixty-three hypoxic patients with suspected PFO-mediated RTLS who underwent SCE at rest, with Valsalva maneuver, and with cough prior to ICE were evaluated retrospectively. PFO RTLS was defined by ICE findings including PFO anatomy, RTLS by saline contrast and color Doppler, and probe patency. SCE shunt severity and timing of left heart saline target appearance were compared to the presence of ICE-defined PFO RTLS. Forty-seven patients (75%) met criteria for PFO-mediated RTLS. A 4 beat cutoff for resting SCE provided optimal diagnostic performance for detection of PFO-mediated RTLS with a 71% sensitivity, 94% specificity, and 97% positive predictive value (PPV). Valsalva and cough maneuvers improved sensitivity compared to rest SCE (89% and 80%, respectively). Valsalva SCE shunt severity more accurately predicted PFO size than resting SCE. In contrast to the widely accepted "3 beat rule," resting SCE for the detection of PFO RTLS in a hypoxic population performs optimally using a 4-cycle cutoff with both excellent specificity and PPV.
Assuntos
Ecocardiografia Doppler em Cores/métodos , Forame Oval Patente/diagnóstico por imagem , Aumento da Imagem/métodos , Cloreto de Sódio , Ultrassonografia de Intervenção/métodos , Idoso , Cateterismo Cardíaco , Cateteres Cardíacos , Estudos de Coortes , Ecocardiografia Transesofagiana/métodos , Feminino , Forame Oval Patente/diagnóstico , Humanos , Hipóxia/diagnóstico , Hipóxia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
Intracardiac flow hemodynamic patterns have been considered to be an early sign of diastolic dysfunction. In this study we investigated right ventricular (RV) diastolic dysfunction between patients with pulmonary arterial hypertension (PAH) and pulmonary hypertension with chronic lung disease (PH-CLD) via 4D-Flow cardiac MRI (CMR). Patients underwent prospective, comprehensive CMR for function and size including 4D-Flow CMR protocol for intracardiac flow visualization and analysis. RV early filling phase and peak atrial phase vorticity (E-vorticity and A-vorticity) values were calculated in all patients. Patients further underwent comprehensive Doppler and tissue Doppler evaluation for the RV diastolic dysfunction. In total 13 patients with PAH, 15 patients with PH-CLD, and 10 control subjects underwent the 4D-Flow CMR and echocardiography evaluation for RV diastolic dysfunction. Reduced E-vorticity differentiated PAH and PH-CLD from healthy controls (both p < 0.01) despite the same Doppler E values. E-vorticity was further decreased in PAH patients when compared to PH-CLD group (p < 0.05) with similar Doppler and tissue Doppler markers of diastolic dysfunction. A-vorticity was decreased in both PAH and PH-CLD groups compared to controls but with no difference between the disease groups. E-vorticity correlated with ejection fraction (R = 0.60, p < 0.001), end-systolic volume (R = 0.50, p = 0.001), stroke volume (R = 0.42, p = 0.007), and cardiac output (R = 0.30, p = 0.027). Intracardiac flow analysis using 4D-Flow CMR derived vorticity is a sensitive method to differentiate diastolic dysfunction in patients with different PH etiology and similar Doppler echocardiography profile.
RESUMO
Cor Pulmonale or right ventricular (RV) dysfunction due to pulmonary disease is an expected complication of COPD resulting primarily from increased afterload mediated by chronic alveolar hypoxemia and resulting hypoxic pulmonary vasoconstriction. Early detection of elevated RV afterload has been previously demonstrated by visualization of abnormal flow patterns in the proximal pulmonary arteries. Prior analysis of helicity in the pulmonary arteries in pulmonary hypertension patients has demonstrated a strong association between helicity and increased RV afterload. However, these flow hemodynamics have yet to be fully explored in patients with COPD. We hypothesized that patients with COPD will have abnormal pulmonary flow as evaluated by 4D-Flow MRI and associated with RV function and pulmonary arterial stiffness. Patients with COPD (n = 15) (65 years ± 6) and controls (n = 10) (58 years ± 9) underwent 4D-Flow MRI to calculate helicity. The helicity was calculated in the main pulmonary artery (MPA) and along the RV outflow tract (RVOT)-MPA axis. Main pulmonary arterial stiffness was measured using the relative area change (RAC). We found COPD patients had decreased helicity relative to healthy controls in the MPA (19.4 ± 7.8vs 32.8 ± 15.9, P = 0.007) and reduced helicity along the RVOT-MPA axis (33.2 ± 9.0 vs 43.5 ± 8.3, P = 0.010). Our investigation indicates a strong association between helicity along the MPA-RV outflow tract axis and RV function and suggests that 4D-Flow MRI might be a sensitive tool in evaluating RV-pulmonary arterial coupling in COPD.
Assuntos
Doença Pulmonar Obstrutiva Crônica , Disfunção Ventricular Direita , Ventrículos do Coração , Humanos , Valor Preditivo dos Testes , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/etiologia , Função Ventricular DireitaRESUMO
Aims: To investigate the possibility that vorticity assessed by four-dimensional flow cardiac magnetic resonance (4D-Flow CMR) in the left ventricle of patients with mild-to-moderate chronic obstructive pulmonary disease (COPD) is a potential marker of early LV diastolic dysfunction (LVDD) and more sensitive than standard echocardiography, and whether changes in vorticity are associated with quantitative computed tomography (CT) and clinical markers of COPD, and right ventricular (RV) echocardiographic markers indicative of ventricular interdependency. Methods and results: Sixteen COPD patients with presumptive LVDD and 10 controls underwent same-day 4D-Flow CMR and Doppler echocardiography to quantify early and late diastolic vorticity as well as standard evaluation for LVDD. Furthermore, all patients underwent detailed CT analysis for COPD markers including percent emphysema and air trapping. The 4D-Flow CMR derived diastolic vorticity measures were correlated with CT measures, standard clinical and CMR markers, and echocardiographic diastolic RV metrics. Early diastolic vorticity was significantly reduced in COPD patients (P < 0.0001) with normal left ventricular (LV) mass, geometry, systolic function, and no or mild signs of Doppler LVDD when compared with controls. Vorticity significantly differentiated COPD patients without echocardiographic signs of LVDD (n = 11) from controls (P < 0.0001), and from COPD patients with stage I LVDD (n = 5) (P < 0.0180). Vorticity markers significantly correlated with CT computed measures, CMR-derived RV ejection fraction, echocardiographic RV diastolic metrics, and 6-minute walk test. Conclusion: 4D-Flow CMR derived diastolic vorticity is reduced in patients with mild-to-moderate COPD and no or mild signs of LVDD, implying early perturbations in the LV flow domain preceding more obvious mechanical changes (i.e. stiffening and dilation). Furthermore, reduced LV vorticity appears to be driven by COPD induced changes in lung tissue and parallel RV dysfunction.
Assuntos
Ecocardiografia Doppler/métodos , Interpretação de Imagem Assistida por Computador , Imagem Cinética por Ressonância Magnética/métodos , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Insuficiência Cardíaca Diastólica/complicações , Insuficiência Cardíaca Diastólica/diagnóstico por imagem , Insuficiência Cardíaca Diastólica/fisiopatologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Volume Sistólico/fisiologia , Disfunção Ventricular Esquerda/complicaçõesRESUMO
To identify a predictive value for the exacerbation status of chronic obstructive pulmonary disease (COPD) subjects, we evaluated the relationship between pulmonary vascular measurements on chest CT and severe COPD exacerbation.Six hundred three subjects enrolled in the COPDGene population were included and divided into nonexacerbator (nâ=â313) and severe exacerbator (nâ=â290) groups, based on whether they had an emergency room visit and/or hospitalization for COPD exacerbation. We measured the diameter of the main pulmonary artery (MPA) and ascending aorta (AA) at 2 different sites of the MPA (the tubular midportion and bifurcation) on both axial images and multiplanar reconstructions. Using multiple logistic regression analyses, we evaluated the relationship between each CT-measured pulmonary vasculature and exacerbation status.Axial and multiplanar MPA to AA diameter ratios (PA:AA ratios) at the tubular midportion and the axial PA:AA ratios at the bifurcation indicated significant association with severe exacerbation. The strongest association was found with the axial PA:mean AA ratio at the bifurcation (adjusted odds ratio [OR]â=â12.53, 95% confidence interval [CI]â=â2.35-66.74, Pâ=â.003) and the axial PA:major AA ratio at the tubular midportion (adjusted ORâ=â10.72, 95% CIâ=â1.99-57.86, Pâ=â.006). No differences were observed in the MPA diameter. Receiver operating characteristic analysis of these variables indicates that they may serve as a good predictive value for severe exacerbation (area under the curve, 0.77-0.78). The range of cut-off value for PA:AA ratio was 0.8 to 0.87.CT-measured PA:AA ratios at either the bifurcation or the tubular site, measured either on axial or multiplanar images, are useful for identification of the risk of severe exacerbation, and consequently can be helpful in guiding the management of COPD. Although CT measurement was used at the level of pulmonary bifurcation in previous studies, we suggest that future studies should monitor the tubular site of the MPA for maximum diagnostic value of CT in pulmonary hypertension or severe COPD exacerbation, as the tubular site of the MPA remains relatively constant on CT images.
Assuntos
Angiografia por Tomografia Computadorizada , Pulmão/irrigação sanguínea , Pulmão/diagnóstico por imagem , Artéria Pulmonar/diagnóstico por imagem , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Progressão da Doença , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
Diastolic dysfunction, a leading cause of heart failure in the US, is a complex pathology which manifests morphological and hemodynamic changes in the heart and circulatory system. Recent advances in time-resolved phase-contrast cardiac magnetic resonance imaging (4D Flow) have allowed for characterization of blood flow in the right ventricle (RV) and right atrium (RA), including calculation of vorticity and qualitative visual assessment of coherent flow patterns. We hypothesize that right ventricular diastolic dysfunction (RVDD) is associated with changes in vorticity and right heart blood flow. This paper presents background on RVDD, and 4D Flow tools and techniques used for quantitative and qualitative analysis of cardiac flows in the normal and disease states. In this study, 20 patients with RVDD and 14 controls underwent cardiac 4D Flow and echocardiography. A method for determining the time-step for peak early diastole using 4D Flow data is described. Spatially integrated early diastolic vorticity was extracted from the RV, RA, and combined RV/RA regions of each subject using a range of vorticity thresholding and scaling methods. Statistically significant differences in vorticity were found in the RA and combined RA/RV in RVDD subjects compared to controls when vorticity vectors were both thresholded and scaled by cardiac index.
RESUMO
BACKGROUND: Qualitative and quantitative flow hemodynamic indexes have been shown to reflect right ventricular (RV) afterload and function in pulmonary hypertension (PH). We aimed to quantify flow hemodynamic formations in pulmonary arteries using 4-dimensional flow cardiac magnetic resonance imaging and the spatial velocity derivatives helicity and vorticity in a heterogeneous PH population. METHODS AND RESULTS: Patients with PH (n=35) and controls (n=10) underwent 4-dimensional flow magnetic resonance imaging study for computation of helicity and vorticity in the main pulmonary artery (MPA), the right pulmonary artery, and the RV outflow tract. Helicity and vorticity were correlated with standard RV volumetric and functional indexes along with MPA stiffness assessed by measuring relative area change. Patients with PH had a significantly decreased helicity in the MPA (8 versus 32 m/s2; P<0.001), the right pulmonary artery (24 versus 50 m/s2; P<0.001), and the RV outflow tract-MPA unit (15 versus 42 m/s2; P<0.001). Vorticity was significantly decreased in patients with PH only in the right pulmonary artery (26 versus 45 1/s; P<0.001). Total helicity computed correlated with the cardiac magnetic resonance imaging-derived ventricular-vascular coupling (-0.927; P<0.000), the RV ejection fraction (0.865; P<0.0001), cardiac output (0.581; P<0.0001), mean pulmonary arterial pressure (-0.581; P=0.0008), and relative area change measured at the MPA (0.789; P<0.0001). CONCLUSIONS: The flow hemodynamic character in patients with PH assessed via quantitative analysis is considerably different when compared with healthy and normotensive controls. A strong association between helicity in pulmonary arteries and ventricular-vascular coupling suggests a relationship between the mechanical and flow hemodynamic domains.
Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Ventrículos do Coração/fisiopatologia , Hipertensão Pulmonar/fisiopatologia , Angiografia por Ressonância Magnética/métodos , Artéria Pulmonar/fisiopatologia , Pressão Propulsora Pulmonar/fisiologia , Função Ventricular Direita/fisiologia , Cateterismo Cardíaco , Feminino , Seguimentos , Ventrículos do Coração/diagnóstico por imagem , Humanos , Hipertensão Pulmonar/diagnóstico , Processamento de Imagem Assistida por Computador , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Artéria Pulmonar/diagnóstico por imagem , Volume SistólicoRESUMO
RATIONALE AND OBJECTIVES: Imaging-based assessment of cardiovascular structure and function provides clinically relevant information in smokers. Non-cardiac-gated thoracic computed tomographic (CT) scanning is increasingly leveraged for clinical care and lung cancer screening. We sought to determine if more comprehensive measures of ventricular geometry could be obtained from CT using an atlas-based surface model of the heart. MATERIALS AND METHODS: Subcohorts of 24 subjects with cardiac magnetic resonance imaging (MRI) and 262 subjects with echocardiography were identified from COPDGene, a longitudinal observational study of smokers. A surface model of the heart was manually initialized, and then automatically optimized to fit the epicardium for each CT. Estimates of right and left ventricular (RV and LV) volume and free-wall curvature were then calculated and compared to structural and functional metrics obtained from MRI and echocardiograms. RESULTS: CT measures of RV dimension and curvature correlated with similar measures obtained using MRI. RV and LV volume obtained from CT inversely correlated with echocardiogram-based estimates of RV systolic pressure using tricuspid regurgitation jet velocity and LV ejection fraction respectively. Patients with evidence of RV or LV dysfunction on echocardiogram had larger RV and LV dimensions on CT. Logistic regression models based on demographics and ventricular measures from CT had an area under the curve of >0.7 for the prediction of elevated right ventricular systolic pressure and ventricular failure. CONCLUSIONS: These data suggest that non-cardiac-gated, non-contrast-enhanced thoracic CT scanning may provide insight into cardiac structure and function in smokers.
Assuntos
Volume Cardíaco/fisiologia , Cardiopatias/diagnóstico , Ventrículos do Coração/diagnóstico por imagem , Pneumopatias/diagnóstico , Fumantes , Tomografia Computadorizada por Raios X/métodos , Função Ventricular/fisiologia , Idoso , Ecocardiografia , Eletrocardiografia , Feminino , Seguimentos , Cardiopatias/etiologia , Cardiopatias/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Pneumopatias/etiologia , Pneumopatias/fisiopatologia , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fumar/efeitos adversos , Volume SistólicoRESUMO
Pulmonary hypertension (PH) is associated with proximal pulmonary arterial remodeling characterized by increased vessel diameter, wall thickening, and stiffness. In vivo assessment of wall shear stress (WSS) may provide insights into the relationships between pulmonary hemodynamics and vascular remodeling. We investigated the relationship between main pulmonary artery (MPA) WSS and pulmonary hemodynamics as well as markers of stiffness. As part of a prospective study, 17 PH patients and 5 controls underwent same-day four-dimensional flow cardiac magnetic resonance imaging (4-D CMR) and right heart catheterization. Streamwise velocity profiles were generated in the cross-sectional MPA in 45° increments from velocity vector fields determined by 4-D CMR. WSS was calculated as the product of hematocrit-dependent viscosity and shear rate generated from the spatial gradient of the velocity profiles. In-plane average MPA WSS was significantly decreased in the PH cohort compared with that in controls (0.18 ± 0.07 vs. 0.32 ± 0.08 N/m(2); P = 0.01). In-plane MPA WSS showed strong inverse correlations with multiple hemodynamic indices, including pulmonary resistance (ρ = -0.74, P < 0.001), mean pulmonary pressure (ρ = -0.64, P = 0.006), and elastance (ρ = -0.70, P < 0.001). In addition, MPA WSS had significant associations with markers of stiffness, including capacitance (ρ = 0.67, P < 0.001), distensibility (ρ = 0.52, P = 0.013), and elastic modulus (ρ = -0.54, P = 0.01). In conclusion, MPA WSS is decreased in PH and is significantly associated with invasive hemodynamic indices and markers of stiffness. 4-D CMR-based assessment of WSS may represent a novel methodology to study blood-vessel wall interactions in PH.
RESUMO
Our objective was to determine whether left ventricular (LV) vorticity (ω), the local spinning motion of a fluid element, correlated with markers of ventricular interdependency in pulmonary hypertension (PH). Maladaptive ventricular interdependency is associated with interventricular septal shift, impaired LV performance, and poor outcomes in PH patients, yet the pathophysiologic mechanisms underlying fluid-structure interactions in ventricular interdependency are incompletely understood. Because conformational changes in chamber geometry affect blood flow formations and dynamics, LV ω may be a marker of LV-RV (right ventricular) interactions in PH. Echocardiography was performed for 13 PH patients and 10 controls for assessment of interdependency markers, including eccentricity index (EI), and biventricular diastolic dysfunction, including mitral valve (MV) and tricuspid valve (TV) early and late velocities (E and A, respectively) as well as MV septal and lateral early tissue Doppler velocities (e'). Same-day 4-dimensional cardiac magnetic resonance was performed for LV E (early)-wave ω measurement. LV E-wave ω was significantly decreased in PH patients (P = 0.008) and correlated with diastolic EI (Rho = -0.53, P = 0.009) as well as with markers of LV diastolic dysfunction, including MV E(Rho = 0.53, P = 0.011), E/A (Rho = 0.56, P = 0.007), septal e' (Rho = 0.63, P = 0.001), and lateral e' (Rho = 0.57, P = 0.007). Furthermore, LV E-wave ω was associated with indices of RV diastolic dysfunction, including TV e' (Rho = 0.52, P = 0.012) and TV E/A (Rho = 0.53, P = 0.009). LV E-wave ω is decreased in PH and correlated with multiple echocardiographic markers of ventricular interdependency. LV ω may be a novel marker for fluid-tissue biomechanical interactions in LV-RV interdependency.
RESUMO
Percutaneous patent foramen ovale (PFO) occluder placement improves dyspnea and oxygen requirement in hypoxic patients with PFO-mediated right-to-left shunt (RTLS). Although saline contrast echocardiography (SCE) in the resting state can identify PFO RTLS, SCE performed with exercise stress testing may provide incremental diagnostic yield compared to rest SCE. We evaluated the ability of exercise SCE to predict PFO presence and size using intracardiac echocardiography (ICE) as a gold standard in a hypoxic cohort. Thirty-three hypoxic patients with suspected PFO RTLS who underwent rest, Valsalva, and exercise stress SCE prior to ICE were evaluated retrospectively. PFO RTLS was defined by ICE findings including PFO anatomy, RTLS by saline contrast and color Doppler, and probe patency. SCE shunt severity was compared to the presence of ICE-defined PFO RTLS and PFO size. Exercise SCE for the detection of PFO RTLS performed with an area under the curve of 0.77, sensitivity of 73%, and specificity of 86%. Among 26 patients with PFO RTLS, exercise SCE identified four additional patients with PFO that had negative rest SCE and two patients with negative Valsalva SCE. Exercise SCE had a stronger correlation with PFO size than resting or Valsalva SCE. Exercise SCE detects PFO RTLS and predicts PFO size in a hypoxic cohort. In addition, exercise SCE can identify PFO RTLS that is otherwise undetected with rest or Valsalva SCE. Exercise SCE may be appropriate when a clinical suspicion for PFO RTLS persists despite negative rest and Valsalva SCE.
Assuntos
Meios de Contraste/administração & dosagem , Ecocardiografia Doppler em Cores , Ecocardiografia sob Estresse/métodos , Teste de Esforço , Forame Oval Patente/diagnóstico por imagem , Hipóxia/diagnóstico por imagem , Cloreto de Sódio/administração & dosagem , Idoso , Área Sob a Curva , Função do Átrio Direito , Pressão Atrial , Cateterismo Cardíaco , Feminino , Forame Oval Patente/complicações , Forame Oval Patente/fisiopatologia , Humanos , Hipóxia/etiologia , Hipóxia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Pressão Propulsora Pulmonar , Curva ROC , Estudos Retrospectivos , Manobra de ValsalvaRESUMO
BACKGROUND: Decreased exercise capacity in chronic obstructive pulmonary disease (COPD) is incompletely explained by pulmonary pathologic and physiologic abnormalities. We evaluated the extent to which right ventricular diastolic function (RVDF) is associated with exercise capacity in COPD. METHODS: Fifty-one patients with COPD were evaluated by echocardiography, spirometry, and the 6 min walk test (6MWT). RVDF was assessed using 4 echocardiographic parameters: 1) the ratio of tricuspid valve (TV) early (E) and late (A) inflow velocities (TV E/A) 2) TV early tissue Doppler velocity (TV e') 3) TV deceleration time (DT) and 4) the ratio of TV E and e' velocities (TV E/e'). Multiple linear regression was used to examine the extent to which these parameters were associated with 6MWT distance. All models adjusted for age, sex, post-bronchodilator FEV1/FVC, resting heart rate, and use of supplemental O2 during 6MWT. A regression model was calculated for each of the 4 markers of RVDF. RESULTS: Forty-seven percent of the sample had GOLD stage III or IV COPD. All 51 subjects had preserved left ventricular ejection fraction (LVEF, mean = 71.7%, SD = 7.8%). A higher TV E/A ratio was associated with increased 6MWT distance (p = 0.001). TV e', TV DT and TV E/e' did not have a statistically significant association with 6MWT distance in regression models. CONCLUSIONS: In a cohort with moderate to severe COPD and normal LVEF, TV E/A was associated with 6MWT distance after adjusting for relevant demographic and medical covariates. RV diastolic dysfunction may independently contribute to exercise intolerance in COPD.
Assuntos
Coração/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Diástole/fisiologia , Ecocardiografia Doppler/métodos , Teste de Esforço/métodos , Tolerância ao Exercício , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Função Ventricular Direita/fisiologia , Caminhada/fisiologiaRESUMO
BACKGROUND: A growing body of evidence has demonstrated that oxidants play a critical role in the pathogenesis of endothelial dysfunction. Pathologic processes fundamental to development and progression of endothelial dysfunction such as the oxidation of LDL, the loss of bioavailable nitric oxide, and the vascular inflammatory response are all modulated by oxidant stress. Therapeutic strategies to reverse endothelial dysfunction have begun to focus on agents with the ability to ameliorate oxidant stress. METHODS: Preclinical and clinical studies evaluating the actions of antioxidants as well as traditional cardiovascular therapies in ameliorating oxidative stress and endothelial dysfunction were reviewed through the use of a MEDLINE search of English language articles published between the years of 1992 and 2002. RESULTS: Antioxidants appear to be an attractive candidate therapy, yet despite compelling preclinical evidence supporting their benefits, efforts to validate the use of vitamins C and E in a clinical setting have been conflicting. In contrast, conventional cardiovascular therapies such as ACE inhibitors, statins, insulin-sensitizing agents, and estrogens have been shown to alleviate endothelial dysfunction, often independent of their effects on systemic disease processes. CONCLUSIONS: These agents restore endothelial function through their salutary effects on pathologic vascular oxidative processes.