RESUMO
Patients with many forms of congenital heart disease (CHD) and hypertrophic cardiomyopathy undergo surgical intervention to relieve left ventricular outflow tract obstruction (LVOTO). Cardiovascular Computed Tomography (CCT) defines the complex pathway from the ventricle to the outflow tract and can be visualized in 2D, 3D, and 4D (3D in motion) to help define the mechanism and physiologic significance of obstruction. Advanced cardiac visualization may aid in surgical planning to relieve obstruction in the left ventricular outflow tract, aortic or neo-aortic valve and the supravalvular space. CCT scanner technology has advanced to achieve submillimeter, isotropic spatial resolution, temporal resolution as low as 66 msec allowing high-resolution imaging even at the fast heart rates and small cardiac structures of pediatric patients ECG gating techniques allow radiation exposure to be targeted to a minimal portion of the cardiac cycle for anatomic imaging, and pulse modulation allows cine imaging with a fraction of radiation given during most of the cardiac cycle, thus reducing radiation dose. Scanning is performed in a single heartbeat or breath hold, minimizing the need for anesthesia or sedation, for which CHD patents are highest risk for an adverse event. Examples of visualization of complex left ventricular outflow tract obstruction in the subaortic, valvar and supravalvular space will be highlighted, illustrating the novel applications of CCT in this patient subset.
Assuntos
Cardiopatias Congênitas , Obstrução da Via de Saída Ventricular Esquerda , Obstrução do Fluxo Ventricular Externo , Humanos , Criança , Obstrução do Fluxo Ventricular Externo/diagnóstico por imagem , Obstrução do Fluxo Ventricular Externo/etiologia , Obstrução do Fluxo Ventricular Externo/cirurgia , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/cirurgia , Tomada de Decisões , TomografiaRESUMO
Children with COVID-associated multisystem inflammatory syndrome (MIS-C) may develop severe disease. We explored the association of admission echocardiographic and laboratory parameters with MIS-C disease severity. This retrospective, single center study of consecutive MIS-C patients (4/2020-12/2021) excluded those with preexisting cardiomyopathy, congenital heart disease, or prior cardiotoxic therapy. Our hypothesis was that worse admission echocardiographic and laboratory parameters were associated with more severe disease based on vasoactive medication use. Univariable and multivariable logistic regression models assessed the association between vasoactive medication use and baseline variables. Of 118 MIS-C patients, median age was 7.8 years (IQR 4.6, 11.8), 48% received vasoactive medication. Higher admission brain natriuretic peptide [OR 1.07 (95% CI 1.02,1.14), p = 0.019], C-reactive protein [OR 1.08 (1.03,1.14), p = 0.002], troponin [OR 1.05 (1.02,1.1), p = 0.015]; lower left ventricular ejection fraction [LVEF, OR 0.96 (0.92,1), p = 0.042], and worse left atrial reservoir strain [OR 0.96 (0.92,1), p = 0.04] were associated with vasoactive medication use. Only higher CRP [OR 1.07 (1.01, 1.11), p = 0.034] and lower LVEF [0.91 (0.84,0.98), p = 0.015] remained independently significant. Among those with normal admission LVEF (78%, 92/118), 43% received vasoactive medication and only higher BNP [OR 1.09 (1.02,1.19), p = 0.021 per 100 pg/mL] and higher CRP [OR 1.07 (1.02,1.14), p = 0.013] were associated with use of vasoactive medication. Nearly half of all children admitted for MIS-C subsequently received vasoactive medication, including those admitted with a normal LVEF. Similarly, admission strain parameters were not discriminatory. Laboratory markers of systemic inflammation and cardiac injury may better predict early MIS-C disease severity.
Assuntos
Ecocardiografia , Função Ventricular Esquerda , Criança , Humanos , Volume Sistólico , Estudos Retrospectivos , Peptídeo Natriurético Encefálico , Gravidade do PacienteRESUMO
Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. In this retrospective cohort study, LAS parameters [reservoir (LAS-r), conduit (LAS-cd), and contractile (LAS-ct)] obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP > 500 pg/ml or troponin-I > 0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. We identified 118 patients with MIS-C and 20 healthy controls. Median LAS parameters were reduced in MIS-C patients compared to controls (LAS-r: 31.8 vs. 43.1%, p < 0.001; LAS-cd: - 28.8 vs. - 34.5%, p = 0.006; LAS-ct: - 5.2 vs. - 9.3%, p < 0.001) and reduced in MIS-C patients with cardiac injury (n = 59) compared to no injury (n = 59) (LAS-r: 29.6 vs. 35.8%, p = 0.001; LAS-cd: - 26.5 vs. - 30.4%, p = 0.036; LAS-ct: - 4.6 vs. - 9.3%, p = 0.008). A discrete LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p < 0.001). Procalcitonin correlated strongly with averaged E/e' (r = 0.55, p = 0.001). Moderate correlations were found for ESR and LAS-ct (r = - 0.41, p = 0.007) as well as BNP and LAS-r (r = - 0.39, p < 0.001) and LAS-ct (r = 0.31, p = 0.023). Troponin-I had only weak correlations. Intra-rater reliability was good for all LAS parameters, and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.
Assuntos
COVID-19/complicações , Síndrome de Resposta Inflamatória Sistêmica , Troponina I , Disfunção Ventricular Esquerda , Adulto , Criança , Humanos , Estudos Retrospectivos , Reprodutibilidade dos Testes , InflamaçãoRESUMO
OBJECTIVE(S): To evaluate the cross-sectional association of cardiovascular disease risk factors with left atrial (LA) size and function among healthy youth, aged 11-18 years, with a wide range of blood pressures (BPs). STUDY DESIGN: Echocardiographic images of youth enrolled in the Study of High Blood Pressure in Pediatrics: Adult Hypertension Onset in Youth study were analyzed for LA measurements. The association of casual BP, ambulatory BP, and other cardiovascular disease risk factors with LA size and function were determined using descriptive statistics and multivariable regression. Regression models adjusting for age, sex, race, and body mass index z score determined the independent association between ambulatory systolic BP indices (mean systolic BP/50th %ile systolic BP) and BP phenotypes with LA outcomes while exploratory analyses investigated for additional predictors of LA outcomes. RESULTS: The study population consisted of 347 youth: median age 15.7 years, 60% male and 40% non-White. Greater-risk casual systolic BP groups had worse cardiometabolic profiles but no differences in LA size and function. Each 0.1 increase in ambulatory systolic BP day or night index was associated with a 9.9 mL/m2 increase in LA volume/body surface area (LAV/BSA; 95th% CI 2.8-17.0, P = .006) and a 6.8 mL/m2 increase in LAV/BSA (95th% CI 0.8-12.8, P = .03), respectively. Ambulatory hypertension was associated with greater odds of abnormal LAV/BSA, defined as >75th %ile (2014 ambulatory BP monitoring criteria: OR 3.2 [95th% CI 1.4-7.2; P = .002]; 2022 ambulatory BP monitoring criteria: OR 2.1 [95th% CI 1.0-4.1; P = .008]). CONCLUSIONS: Increasing ambulatory systolic BP and ambulatory hypertension are independently associated with LAV/BSA.
Assuntos
Fibrilação Atrial , Hipertensão , Humanos , Masculino , Adolescente , Criança , Feminino , Pressão Sanguínea/fisiologia , Estudos Transversais , Hipertensão/epidemiologia , Hipertensão/complicações , Átrios do Coração/diagnóstico por imagem , Monitorização Ambulatorial da Pressão ArterialRESUMO
BACKGROUND: Hypertrophic cardiomyopathy (HCM), a disease with myocardial fibrosis manifestation, is a common cause of sudden cardiac death (SCD) due to ventricular arrhythmias (VA). Current clinical risk stratification criteria are inadequate in identifying patients who are at risk for VA and in need of an implantable cardioverter defibrillator (ICD) for primary prevention. OBJECTIVE: We aimed to develop a risk prediction approach based on imaging biomarkers from the combination of late gadolinium contrast-enhanced (LGE) MRI and T1 mapping. We then aimed to compare the prediction to a virtual heart computational risk assessment approach based on LGE-T1 virtual heart models. METHODS: The methodology involved combining short-axis LGE-MRI with post-contrast T1 maps to define personalized thresholds for diffuse and dense fibrosis. The combined LGE-T1 maps were used to evaluate imaging biomarkers for VA risk prediction. The risk prediction capability of the biomarkers was compared with that of the LGE-T1 virtual heart arrhythmia inducibility simulation. VA risk prediction performance from both approaches was compared to clinical outcome (presence of clinical VA). RESULTS: Image-based biomarkers, including hypertrophy, signal intensity heterogeneity, and fibrotic border complexity, could not discriminate high vs low VA risk. LGE-T1 virtual heart technology outperformed all the image-based biomarker metrics and was statistically significant in predicting VA risk in HCM. CONCLUSIONS: We combined two MR imaging techniques to analyze imaging biomarkers in HCM. Raw and processed image-based biomarkers cannot discriminate patients with VA from those without VA. Hybrid LGE-T1 virtual heart models could correctly predict VA risk for this cohort and may improve SCD risk stratification to better identify HCM patients for primary preventative ICD implantation.
Assuntos
Cardiomiopatia Hipertrófica , Eletrocardiografia , Humanos , Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Imageamento por Ressonância Magnética , TecnologiaRESUMO
OBJECTIVE: To assess prevalence of and factors associated with left ventricular diastolic dysfunction (LVDD) in youth with obesity and elevated blood pressure (BP). STUDY DESIGN: This was a cross-sectional analysis of baseline and follow-up visits of 83 youth, 5-21 years, evaluated for overweight/obesity and elevated BP in a multidisciplinary clinic. LVDD was defined according to established adult criteria (LVDDadult; E/A < 1, E/e' > 14, or e'/a' < 0.8) and pediatric criteria (LVDDpeds; E/A <10th percentile, E/e' >99th percentile, or e'/a' <1st percentile) based on data from 103 age-sex matched healthy controls. Baseline factors associated with LVDDpeds were examined using Wilcoxon rank sum and χ2 tests. Multiple logistic regression analyses using generalized estimating equations to account for repeated measures evaluated the associations of adiposity and BP with LVDDpeds. RESULTS: The prevalence of LVDD ranged from 1.2% to 2.7% when we used adult criteria and 19% to 28% when we used pediatric criteria. Those with LVDDpeds were older, predominantly male, and non-African American and had greater weight, BP, BP medication use, and non-high-density lipoprotein cholesterol than those without LVDDpeds. Diastolic BP z score was associated with LVDDpeds by E/A (OR 1.95, 95% CI 1.15-3.32, P = .014) after we adjusted for age, sex, race, BP medications, and body mass index z score. CONCLUSIONS: LVDD was present in a substantial proportion of youth with overweight/obesity and elevated BP using pediatric criteria. Those with LVDDpeds had significantly greater measures of adiposity and BP compared with those without LVDDpeds, and diastolic BP z score was an independent predictor of LVDDpeds by E/A. These data emphasize the importance of prevention and treatment of cardiovascular disease risk factors in childhood.
Assuntos
Diástole , Hipertensão/epidemiologia , Obesidade Infantil/epidemiologia , Disfunção Ventricular Esquerda/epidemiologia , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , Estudos Transversais , Feminino , Seguimentos , Humanos , Lipoproteínas HDL/análise , Masculino , Distribuição por Sexo , Adulto JovemRESUMO
PURPOSE OF REVIEW: To review the most recent literature on current strategies for the treatment of hypertension associated with pediatric obesity. RECENT FINDINGS: Over the last three decades, childhood and adolescent overweight and obesity prevalence in the USA has continued to rise. Unsurprisingly but rather disturbingly, this rising prevalence has been paralleled by an increase in cardiovascular disease (CVD) risk factors in childhood such as hypertension, dyslipidemia, and diabetes that become manifest earlier than previously reported. These childhood CVD risk factors are not only associated with target organ damage in childhood but also track into adulthood, increasing the risk of long-term CVD morbidity and mortality. There have been several mechanisms proposed to explain the role of obesity on the development of hypertension in childhood. However, central to the management of obesity-related hypertension is a multifaceted approach targeting lifestyle modifications and weight loss. Effective treatment often also requires a pharmacologic approach and rarely bariatric surgery.
Assuntos
Dislipidemias , Hipertensão , Obesidade Infantil , Adolescente , Adulto , Criança , Dislipidemias/complicações , Dislipidemias/tratamento farmacológico , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Estilo de Vida , Obesidade Infantil/complicações , Fatores de Risco , Redução de PesoRESUMO
A right aortic arch with an isolated left innominate artery is a rare form of aortic arch anomaly. We present a case of neonatal diagnosis of this anomaly with concerning findings of global cerebral white matter atrophy at 13 months of age.
Assuntos
Aorta Torácica/anormalidades , Tronco Braquiocefálico/anormalidades , Substância Branca/patologia , Aorta Torácica/diagnóstico por imagem , Atrofia , Tronco Braquiocefálico/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Lactente , Recém-Nascido , Substância Branca/diagnóstico por imagemRESUMO
Aneurysms of the right atrium are rare in the paediatric population. We report a case of a foetal diagnosis of right atrial aneurysm with associated atrial tachycardia in foetal and postnatal life. Unique to our case are the findings of isolated pericardial effusion without hydrops fetalis and the development of aortic coarctation in postnatal life.
Assuntos
Coartação Aórtica/complicações , Coartação Aórtica/diagnóstico , Aneurisma Cardíaco/complicações , Aneurisma Cardíaco/diagnóstico , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico , Adulto , Coartação Aórtica/cirurgia , Feminino , Aneurisma Cardíaco/cirurgia , Humanos , Recém-Nascido , Gravidez , Ultrassonografia Pré-Natal , Disfunção Ventricular Esquerda/cirurgiaRESUMO
Experimental data on pulmonary regurgitation has linked right ventricular longitudinal function to left ventricular filling pressure in animals with induced and treated pulmonary regurgitation but this relationship has not been investigated in patients with repaired Tetralogy of Fallot (rToF). The aim of this study was to determine if right ventricular longitudinal function assessed using cardiovascular magnetic resonance (CMR) is associated with left ventricular filling pressure in patients with rToF. A second objective of this study was to determine if direction of septal movement is related to right ventricular pressure load in rToF. Eighteen patients with rToF undergoing CMR and heart catheterization prior to pulmonary valve replacement were retrospectively included and catheter-based pressure measurements were compared with CMR-derived RV regional function. Left ventricular filling pressure was measured as precapillary wedge pressure (PCWP). Longitudinal contribution to RV stroke volume correlated with PCWP (r = 0.48; p = 0.046) but not with RV EF or pulmonary regurgitation. Neither RV longitudinal strain nor TAPSE showed correlation with PCWP. Longitudinal contribution to stroke volume was lower for the RV compared to the LV (49 vs 54%; p = 0.039). Direction of septal movement did not show a correlation with RV end-systolic pressure. Right ventricular longitudinal pumping is associated with left ventricular filling pressure in rToF-patients and this inter-ventricular coupling may explain LV underfilling in patients with pulmonary regurgitation and rToF and may be of value to determine right ventricular dysfunction. RV systolic pressure, however, cannot be assessed from the direction of septal movement, in these patients.
Assuntos
Insuficiência da Valva Pulmonar , Tetralogia de Fallot , Disfunção Ventricular Direita , Humanos , Estudos Retrospectivos , Valor Preditivo dos Testes , Imageamento por Ressonância Magnética , Função Ventricular DireitaRESUMO
Background: Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. Methods: In this retrospective cohort study, conventional parameters and LAS (reservoir [LAS-r], conduit [LAS-cd], and contractile [LAS-ct]) obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP >500 pg/ml or troponin-I >0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. Results: Median LAS components were reduced in MIS-C patients (n=118) compared to controls (n=20) (LAS-r: 31.8 vs. 43.1%, p<0.001; LAS-cd: -28.8 vs. -34.5%, p=0.006; LAS-ct: -5.2 vs. -9.3%, p<0.001) and reduced in MIS-C patients with cardiac injury (n=59) compared to no injury (n=59) (LAS-r: 29.6 vs. 35.8%, p=0.001; LAS-cd: -26.5 vs. -30.4%, p=0.036; LAS-ct: -4.6 vs. -9.3%, p=0.008). An LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p<0.001). Procalcitonin had strong correlation with averaged E/e' (r=0.55, p=0.001); ESR had moderate correlation with LAS-ct (r=-0.41, p=0.007); BNP had moderate correlation with LAS-r (r=-0.39, p<0.001) and LAS-ct (r=0.31, p=0.023), and troponin-I had only weak correlations. No strain indices were independently associated with cardiac injury on regression analysis. Intra-rater reliability was good for all LAS components; and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. Conclusions: LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.
RESUMO
Cardiovascular computed tomography (CCT) is rated appropriate by published guidelines for the initial evaluation and follow up of congenital heart disease (CHD) and is an essential modality in cardiac imaging programs for patients of all ages. However, no recommended core competencies exist to guide CCT in CHD imaging training pathways, curricula development, or establishment of a more formal educational platform. To fill this gap, a group of experienced congenital cardiac imagers, intentionally inclusive of adult and pediatric cardiologists and radiologists, was formed to propose core competencies fundamental to the expert-level performance of CCT in pediatric acquired and congenital heart disease and adult CHD. The 2020 SCCT Guideline for Training Cardiology and Radiology Trainees as Independent Practitioners (Level II) and Advanced Practitioners (Level III) in Cardiovascular Computed Tomography (1) for adult imaging were used as a framework to define pediatric and CHD-specific competencies. Established competencies will be immediately relevant for advanced cardiac imaging fellowships in both cardiology and radiology training pathways. Proposed future steps include radiology and cardiology society collaboration to establish provider certification levels, training case-volume recommendations, and continuing medical education (CME) requirements for expert-level performance of CCT in pediatric and adult CHD.
Assuntos
Cardiologia , Cardiopatias Congênitas , Humanos , Criança , Adulto , Cardiopatias Congênitas/diagnóstico por imagem , Valor Preditivo dos Testes , Cardiologia/educação , Técnicas de Imagem Cardíaca , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Guidelines addressing magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) provide algorithms for imaging pediatric and congenital heart disease (CHD) patients. Guideline acceptance varies by institution. Guidelines also do not support routine MRI scans in patients with epicardial or abandoned leads, common in pediatric and CHD patients. OBJECTIVE: The purpose of this study was to determine the incidence of MRI-related complications in pediatric and CHD patients with CIEDs, including epicardial and/or abandoned leads. METHODS: A multicenter retrospective review included patients with CIEDs who underwent any MRI between 2007 and 2022 at congenital cardiac centers. The primary outcome was any patient adverse event or clinically significant CIED change after MRI, defined as pacing lead capture threshold increase >0.5 V with output change, P- or R- wave amplitude decrease >50% with sensitivity change, or impedance change >50%. RESULTS: Across 14 institutions, 314 patients (median age 18.8 [1.3; 31.4] years) underwent 389 MRIs. There were 288 pacemakers (74%) and 87 implantable cardioverter-defibrillators (22%); 52% contained epicardial leads, and 14 (4%) were abandoned leads only. Symptoms or CIED changes occurred in 4.9% of MRI scans (6.1% of patients). On 9 occasions (2%), warmth or pain occurred. Pacing capture threshold or lead impedance changes occurred in 1.4% and 2.0% of CIEDs post-MRI and at follow-up. CONCLUSION: Our data provide evidence that MRIs can be performed in pediatric and CHD patients with CIEDs, including non-MRI-conditional CIEDs and epicardial and/or abandoned leads, with rare minor symptoms or CIED changes but no other complications.
Assuntos
Desfibriladores Implantáveis , Cardiopatias Congênitas , Marca-Passo Artificial , Adolescente , Criança , Humanos , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/terapia , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Lactente , Pré-Escolar , Adulto Jovem , AdultoRESUMO
Patients with tetralogy of Fallot (TOF) may undergo pulmonary valve replacement (PVR) after initial full repair. We investigated indices of biventricular function, work and efficiency of TOF patients' using noninvasive pressure-volume (PV) loop analysis on cardiovascular magnetic resonance (CMR) images and compared pre-and post PVR groups. Biventricular segmentations of steady state free precession CMR images were performed using custom validated software (Segment version 2.0 R7067). Brachial cuff pressure estimated left ventricular (LV) systolic pressure. Right ventricular (RV) inputs were obtained from pre-PVR cardiac catheterization data. Biventricular PV loops were then derived using a time-varying elastance model. Twenty seven patients were studied: (22 pre-PVR, 5 post-PVR), mean age of 20±10.5 years and 83% male. RV stroke volume significantly differed before and after PVR (73.2±25 ml vs. 41±10 mL, P =0.01). RV stroke work (SW) and mean external power (MEP) were significantly less post-PVR, but there were no significant differences in the LV hemodynamic indices. TOF patients have reduced RV SW and MEP post-PVR suggesting improved hemodynamics. Noninvasive biventricular PV loop analysis shows potential for integration into standard CMR imaging of TOF and provides hemodynamic data that could influence management decisions.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Pulmonar , Valva Pulmonar , Tetralogia de Fallot , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Valva Pulmonar/diagnóstico por imagem , Valva Pulmonar/cirurgia , Insuficiência da Valva Pulmonar/diagnóstico por imagem , Insuficiência da Valva Pulmonar/cirurgia , Tetralogia de Fallot/diagnóstico por imagem , Tetralogia de Fallot/cirurgia , Resultado do Tratamento , Adulto JovemRESUMO
Hypertrophic cardiomyopathy (HCM) is associated with risk of sudden cardiac death (SCD) due to ventricular arrhythmias (VAs) arising from the proliferation of fibrosis in the heart. Current clinical risk stratification criteria inadequately identify at-risk patients in need of primary prevention of VA. Here, we use mechanistic computational modeling of the heart to analyze how HCM-specific remodeling promotes arrhythmogenesis and to develop a personalized strategy to forecast risk of VAs in these patients. We combine contrast-enhanced cardiac magnetic resonance imaging and T1 mapping data to construct digital replicas of HCM patient hearts that represent the patient-specific distribution of focal and diffuse fibrosis and evaluate the substrate propensity to VA. Our analysis indicates that the presence of diffuse fibrosis, which is rarely assessed in these patients, increases arrhythmogenic propensity. In forecasting future VA events in HCM patients, the imaging-based computational heart approach achieved 84.6%, 76.9%, and 80.1% sensitivity, specificity, and accuracy, respectively, and significantly outperformed current clinical risk predictors. This novel VA risk assessment may have the potential to prevent SCD and help deploy primary prevention appropriately in HCM patients.
Assuntos
Cardiomiopatia Hipertrófica/diagnóstico por imagem , Simulação por Computador , Imageamento por Ressonância Magnética , Taquicardia Ventricular/etiologia , Adulto , Idoso , Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/patologia , Cardiomiopatia Hipertrófica/fisiopatologia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Feminino , Fibrose , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/terapia , Adulto JovemRESUMO
Microtubules are hollow cylindrical polymers of the protein tubulin that play a number of important dynamic and structural roles in eukaryotic cells. Both in vivo and in vitro microtubules can exist in several possible configurations, differing in the number of protofilaments, helical rise of tubulin dimers, and protofilament skew angle with respect to the main tube axis. Here, finite element modeling is applied to examine the mechanical response of several known microtubule types when subjected to radial deformation. The data presented here provide an important insight into microtubule stiffness and reveal that protofilament orientation does not affect radial stiffness. Rather, stiffness is primarily dependent on the effective Young's modulus of the polymerized material and the effective radius of the microtubule. These results are also directly correlated to atomic force microscopy nanoindentation measurements to allow a more detailed interpretation of previous experiments. When combined with experimental data that show a significant difference between microtubules stabilized with a slowly hydrolyzable GTP analog and microtubules stabilized with paclitaxel, the finite element data suggest that paclitaxel increases the overall radial flexibility of the microtubule wall.
Assuntos
Fenômenos Mecânicos , Microtúbulos/química , Microtúbulos/metabolismo , Fenômenos Biomecânicos , Análise de Elementos Finitos , Microscopia de Força Atômica , Modelos Moleculares , Conformação MolecularRESUMO
AIMS: Congenital coronary artery anomalies are uncommon and may result in sudden death. Management of asymptomatic patients with anomalous aortic origin of the right coronary artery (AAORCA) remains controversial with a lack of evidence to guide decision-making. We hypothesized that patients with AAORCA may have exercise-inducible ischemia detectable as abnormalities in regional myocardial deformation on exercise stress echocardiography (ESE). METHODS: We reviewed clinical data, computed tomography angiography, and treadmill ESE from 33 AAORCA patients (21 unoperated, 12 operated) and 11 controls. Regional wall motion on ESE was visually assessed. Doppler tissue imaging was done pre and post exercise to evaluate regional myocardial wall deformation. The post- to pre-exercise time to peak systolic strain corrected for heart rate ratio (TPScR) for the left ventricular inferior and anterior walls of AAORCA patients was compared to controls. RESULTS: No regional wall motion abnormalities were noted. The TPScR of the inferior wall was higher in unoperated (0.96 ± 0.41) but not operated (0.84 ± 0.28) AAORCA patients compared to controls (0.76 ± 0.18, P = .03 vs .23, respectively). There was no significant difference in TPScR of the anterior wall between unoperated patients and controls (P = .08). CONCLUSION: In some AAORCA patients undergoing ESE, TPScR of the left ventricular inferior wall is elevated, suggestive of ischemia induced by exercise in myocardium supplied by the right coronary artery. Further work is needed to understand the potential role of this finding in risk assessment.
Assuntos
Aorta Torácica/anormalidades , Circulação Coronária/fisiologia , Anomalias dos Vasos Coronários/diagnóstico , Ecocardiografia sob Estresse/efeitos adversos , Contração Miocárdica/fisiologia , Isquemia Miocárdica/etiologia , Adolescente , Adulto , Criança , Pré-Escolar , Anomalias dos Vasos Coronários/complicações , Anomalias dos Vasos Coronários/fisiopatologia , Eletrocardiografia , Teste de Esforço/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatologia , Miocárdio , Adulto JovemRESUMO
BACKGROUND: Adults with repaired tetralogy of Fallot (rTOF) are at increased risk for ventricular tachycardia (VT) due to fibrotic remodeling of the myocardium. However, the current clinical guidelines for VT risk stratification and subsequent implantable cardioverter-defibrillator deployment for primary prevention of sudden cardiac death in rTOF remain inadequate. OBJECTIVE: The purpose of this study was to determine the feasibility of using an rTOF-specific virtual-heart approach to identify patients stratified incorrectly as being at low VT risk by current clinical criteria. METHODS: This multicenter retrospective pilot study included 7 adult rTOF patients who were considered low risk for VT based on clinical criteria. Patient-specific computational heart models were generated from late gadolinium enhanced magnetic resonance imaging (LGE-MRI), incorporating the individual distribution of rTOF fibrotic remodeling in both ventricles. Simulations of rapid pacing determined VT inducibility. Model creation and simulations were performed by operators blinded to clinical outcome. RESULTS: Two patients in the study experienced clinical VT. The virtual hearts constructed from LGE-MRI scans of 7 rTOF patients correctly predicted reentrant VT in the models from VT-positive patients and no arrhythmia in those from VT-negative patients. There were no statistically significant differences in clinical criteria commonly used to assess VT risk, including QRS duration and age, between patients who did and those who did not experience clinical VT. CONCLUSION: This study demonstrates the feasibility of image-based virtual-heart modeling in patients with congenital heart disease and structurally abnormal hearts. It highlights the potential of the methodology to improve VT risk stratification in patients with rTOF.
Assuntos
Simulação por Computador , Ventrículos do Coração/fisiopatologia , Miocárdio/patologia , Taquicardia Ventricular/etiologia , Tetralogia de Fallot/complicações , Remodelação Ventricular , Adolescente , Adulto , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Estudos Retrospectivos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Tetralogia de Fallot/cirurgia , Adulto JovemRESUMO
Obesity is a potent cardiovascular disease (CVD) risk factor and is associated with left ventricular hypertrophy (LVH). Obstructive sleep apnea (OSA) is common among individuals with obesity and is also associated with CVD risk. The authors sought to determine the association of OSA, a modifiable CVD risk factor, with LVH among overweight/obese youth with elevated blood pressure (EBP). This was a cross-sectional analysis of the baseline visit of 61 consecutive overweight/obese children with history of EBP who were evaluated in a pediatric obesity hypertension clinic. OSA was defined via sleep study or validated questionnaire. Children with and without OSA were compared using Fisher's exact tests, Student's t tests, and Wilcoxon rank sum test. Multivariable logistic regression evaluated the association between OSA and LVH. In this cohort, 71.7% of the children had LVH. Children with OSA were more likely to have LVH (85.7% vs 59.4%, P = 0.047). OSA was associated with 4.11 times greater odds of LVH (95% CI 1.15, 14.65; P = 0.030), remaining significant after adjustment for age, sex, race, and BMI z-score (after adjustment for hypertension, P = 0.051). A severe obstructive apnea-hypopnea index (AHI >10) was associated with 14 times greater odds of LVH (95% CI 1.14, 172.64, P = 0.039). OSA was significantly associated with LVH among overweight/obese youth with EBP, even after adjustment for age, sex, race, and BMI z-score. Those with the most severe OSA (AHI >10) had the greatest risk for LVH. Future studies exploring the impact of OSA treatment on CVD risk in children are needed.