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Plants have evolved many systems to sense their environment and to modify their growth and development accordingly. One example is vernalization, the process by which flowering is promoted as plants sense exposure to the cold temperatures of winter. A requirement for vernalization is an adaptive trait that helps prevent flowering before winter and permits flowering in the favorable conditions of spring. In Arabidopsis and cereals, vernalization results in the suppression of genes that repress flowering. We describe recent progress in understanding the molecular basis of this suppression. In Arabidopsis, vernalization involves the recruitment of chromatin-modifying complexes to a clade of flowering repressors that are silenced epigenetically via histone modifications. We also discuss the similarities and differences in vernalization between Arabidopsis and cereals.
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Arabidopsis/fisiología , Grano Comestible/fisiología , Flores/fisiología , Fenómenos Fisiológicos de las Plantas , Estaciones del AñoRESUMEN
Infections with the coccidian parasite Neospora caninum affect domestic and wild animals worldwide. In Australia, N. caninum infections cause considerable losses to the cattle industry with seroprevalence of 8.7% in beef and 10.9% in dairy cattle. Conversely, the role of wild animals, in maintaining the parasite cycle is also unclear. It is possible that native or introduced herbivorous species could be reservoir hosts of N. caninum in Australia, but to date, this has not been investigated. We report here the first large-scale screening of N. caninum antibodies in Australian wild deer, spanning three species (fallow, red and sambar deer). Consequently, we also assessed two commercial cELISA tests validated for detecting N. caninum in cattle for their ability to detect N. caninum antibodies in serum samples of wild deer. N. caninum antibodies were detected in 3.7% (7/189, 95% CI 1.8 - 7.45) of the wild deer serum samples collected in south-eastern Australia (n = 189), including 97 fallow deer (Dama dama), 14 red deer (Cervus elaphus), and 78 sambar deer (Rusa unicolor). Overall, our study provides the first detection of N. caninum antibodies in wild deer and quantifies deer's potential role in the sylvatic cycle of N. caninum.
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Antígenos de Grupos Sanguíneos , Ciervos , Animales , Bovinos , Animales Salvajes , Estudios Seroepidemiológicos , Australia/epidemiología , AmbienteRESUMEN
BACKGROUND: Approximately 20-30% of ischemic strokes are caused by internal carotid artery stenosis. Stroke is the leading cause of disability and the second leading cause of death in the United States. Second generation transcarotid arterial revascularization (TCAR) stenting, using the ENROUTE flow reversal technology to prevent embolic stroke during the stenting process, has demonstrated stroke and death outcomes equivalent to carotid endarterectomy with reduced cranial nerve injury. However, at present, it is not known whether imaging characteristics obtained preoperatively can predict outcomes of TCAR procedures. METHODS: This retrospective cohort study included patients who underwent TCAR with flow reversal at three hospitals within a single hospital network who had computed tomography angiography, magnetic resonance imaging angiography, or preoperative diagnostic angiogram to determine whether carotid and lesion characteristics could predict patients who experienced major adverse critical events (MACE) versus those who did not. MACE was defined as myocardial infarction at 30 days, restenosis/persistent stenosis (peak systolic velocity within the stent >230 cm/sec by postoperative ultrasound), stroke within any time of follow-up, or death within 1 year of TCAR. Student's t-tests and Chi-squared tests were used to compare imaging characteristics, such as presence of pinpoint stenosis, calcification within the common carotid artery at the take-off from the aorta, and plaque length in millimeters. Binomial logistic regression was used to examine the likelihood that imaging characteristics were associated with MACE. RESULTS: Of 220 patients who underwent TCAR in our network, seven were excluded because flow reversal was not used or appropriate imaging had not been performed prior to TCAR. Of the 213 patients who were included in analysis, the median length of follow-up was 10.8 months (interquartile range: 3.4-33.1 months). Twelve percent (26/213) experienced MACE and a model based on imaging characteristics was statistically significant in predicting MACE with 68% accuracy (P = 0.005). The presence of pinpoint stenosis was highly predictive of MACE (hazards ratio: 3.34, confidence interval: 1.2 to 9.3, P = 0.021). A shorter clavicle to carotid bifurcation distance was associated with an increased likelihood of experiencing MACE (P = 0.009) but it was weakly predictive (hazards ratio: 1.03, confidence interval: 1.01 to 1.05). CONCLUSIONS: Preoperative imaging characteristics, such as pinpoint stenosis and clavicle to carotid bifurcation distance, can be used to predict adverse outcomes in TCAR placement.
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Estenosis Carotídea , Endarterectomía Carotidea , Procedimientos Endovasculares , Accidente Cerebrovascular , Humanos , Estados Unidos , Estudios Retrospectivos , Procedimientos Endovasculares/efectos adversos , Constricción Patológica/etiología , Factores de Riesgo , Resultado del Tratamiento , Factores de Tiempo , Endarterectomía Carotidea/efectos adversos , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/cirugía , Stents/efectos adversos , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/complicaciones , Arterias CarótidasRESUMEN
BACKGROUND: Cardiovascular implantable electronic devices (CIEDs) have historically restricted the use of magnetic resonance imaging (MRI) due to the potential clinical and configurational risks associated with electromagnetic interference. In this study, the authors investigated the impact of MRI on the functional integrity of non-conditional CIEDs and their clinical correlates. METHODS: In this prospective, observational single-center study, we enrolled patients undergoing MRI over a 5-year period. Prior to assessing the impact of MRI on CIEDs, we performed interrogations in sequential duplication to assess the intrinsic variability of devices. Subsequently, we performed interrogations immediately after MRI, and monitored changes in device parameters and clinical events. RESULTS: We completed 492 MRI studies, 58% in patients with permanent pacemakers (PPMs) and 42% with implantable cardioverter defibrillators (ICDs). Subsequent MRI exposures occurred in 15% encounters. Accounting for intrinsic variability in CIED leads, there were no significant changes in RA, RV, or LV parameters after MRI, regardless of the region imaged (thoracic vs. non-thoracic), type of CIED (PPMs vs. ICDs) and among those with serial MRIs. When ranked for % change pre- to post-MRI, the majority of RA, RV, and LV metrics for thresholds, sensing, and impedance conformed to ≤20% change from baseline. No significant clinical adverse cardiac events or effect on device microcircuitry occurred during the study. CONCLUSION: Incorporating a novel reproducibility tactic, there were neither clinically meaningful device parameter changes nor adverse clinical events during or following MRIs, suggesting the effects of MRI on non-conditional CIED integrity are far less than previously perceived.
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Dispositivos de Terapia de Resincronización Cardíaca , Imagen por Resonancia Magnética/métodos , Seguridad del Paciente , Anciano , Contraindicaciones , Falla de Equipo , Femenino , Reacción a Cuerpo Extraño , Humanos , Masculino , Estudios ProspectivosRESUMEN
PURPOSE OF REVIEW: For over 20 years, the Women's Ischemia Syndrome Evaluation (WISE), a program sponsored by the National Heart, Lung, and Blood Institute, has explored diverse and important aspects of ischemic heart disease in women. RECENT FINDINGS: Women with symptoms and signs of ischemia but no significant epicardial obstructive coronary artery disease (INOCA) were documented to be at elevated risk for recurrent angina hospitalization, major adverse cardiac events, death, and health resource consumption rivaling those with obstructive coronary disease. WISE investigators have advanced our understanding of cardiovascular outcomes, systemic manifestations, psychological variables, socioeconomic factors, genetic contributions, hormonal status, advanced imaging, coronary functional findings, biomarkers, patient-reported outcomes, and treatments pertaining to women with this disease entity. This review delves into the WISE findings subsequent to a prior review1, postulates directions for future research, and asks are we "Even 'WISE-R?'".
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Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/epidemiología , Isquemia Miocárdica/diagnóstico por imagen , Isquemia Miocárdica/epidemiología , National Heart, Lung, and Blood Institute (U.S.) , Biomarcadores/sangre , Estudios de Cohortes , Comorbilidad , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Isquemia Miocárdica/sangre , Isquemia Miocárdica/tratamiento farmacológico , Tomografía de Emisión de Positrones/métodos , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: The preoperative workup of orthotopic liver transplantation (OLT) patients is practically complex given the need for multiple imaging modalities. We recently demonstrated in our proof-of-concept study the value of a one-stop-shop approach using cardiovascular MRI (CMR) to address this complex problem. However, this approach requires further validation in a larger cohort, as detection of hepatocellular carcinoma (HCC) as well as cardiovascular risk assessment is critically important in these patients. We hypothesized that coronary risk assessment and HCC detectability is acceptable using the one-stop-shop CMR approach. METHODS: In this observational study, patients underwent CMRI evaluation including cardiac function, stress CMR, thoracoabdominal MRA, and abdominal MRI on a standard MRI scanner in one examination. RESULTS: Over 8 years, 252 OLT candidates underwent evaluation in the cardiac MRI suit. The completion rates for each segment of the CMR examination were 99% for function, 95% completed stress CMR, 93% completed LGE for viability, 85% for liver MRI, and 87% for MRA. A negative CMR stress examination had 100% CAD event-free survival at 12 months. A total of 63 (29%) patients proceeded to OLT. Explant pathology confirmed detection/exclusion of HCC. CONCLUSIONS: This study further defines the population suitable for the one-stop-shop CMR concept for preop evaluation of OLT candidates providing a road map for integrated testing in this complex patient population for evaluation of cardiac risk and detection of HCC lesions.
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Carcinoma Hepatocelular/patología , Cardiopatías/patología , Fallo Hepático/cirugía , Neoplasias Hepáticas/patología , Trasplante de Hígado/efectos adversos , Imagen por Resonancia Magnética/métodos , Medición de Riesgo/métodos , Carcinoma Hepatocelular/etiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Cardiopatías/etiología , Humanos , Neoplasias Hepáticas/etiología , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios , PronósticoRESUMEN
A review of the unique and complementary roles echocardiography and cardiovascular MRI provide to the clinician. A focus on the physics of each modality as well as imaging of the left ventricle.
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Ecocardiografía/métodos , Cardiopatías/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Ventrículos Cardíacos/diagnóstico por imagen , HumanosRESUMEN
In diagnosing cardiac and paracardiac masses, cardiac MRI (CMR) has gained acceptance as the gold standard. CMR has been observed to be superior to echocardiography in characterizing soft-tissue structures and, specifically, in classifying cardiac masses. The aim of our study was to evaluate the association between mortality and cardiac or paracardiac masses initially identified by echocardiography (ECHO) and confirmed by CMR. Between January 2002 and August 2007, a total of 158 patients underwent both ECHO and CMR for the evaluation of cardiac masses that were equivocal or undefined by ECHO. The primary study endpoints were 5-year all-cause mortality and 5-year cardiac mortality. Causes of death as of April 1, 2015 were obtained from medical records or the National Death Index. Patients were analyzed according to mass type determined by CMR using the Kruskal-Wallis test, Kaplan-Meier curves, and the log-rank test. Over a mean duration of follow-up of 10.4 ± 2.9 years (range: 0.01-12 years) post-CMR, the overall all-cause mortality rate was 25.9% (41/158). Median age at death was 76 years and there were 21 females (51.2%). Mortality rates in the different classifications of cardiac masses by CMR were as follows: 20% (1/5) in patients with a Nondiagnostic CMR; 20% (1/5) in Other Diagnoses; 17.9% (7/39) in No Masses (includes Normal Anatomical Variants); 16.7% (3/18) in Benign Masses; 23.8% (15/63) in Fat; 50% (5/10) in Thrombus; and 61.5% (8/13) in Malignant Mass. The mean survival time in patients with No Mass (n = 39) was not significantly longer than patients with any type of cardiac mass (n = 114) (P = .16). No significant difference was found in age at death between patients when grouped by CMR classification (P = .40). However, among CMR-confirmed masses, there were some significant differences by mass classification type (P = .006). During the follow-up period, 26% (41/158) of patients died and 22% (9/41) of the deaths were cardiovascular related; there was no significant difference in mean survival times with respect to cause of mortality (P = .23). In patients with cardiac masses, dually confirmed by ECHO and CMR, significant differences in survival time were observed based upon CMR classified type of mass while CMR was instrumental in obviating invasive biopsy.
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Ecocardiografía/métodos , Predicción , Neoplasias Cardíacas/diagnóstico , Imagen por Resonancia Cinemagnética/métodos , Pericardio , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Causas de Muerte/tendencias , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Neoplasias Cardíacas/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Pennsylvania/epidemiología , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Adulto JovenRESUMEN
BACKGROUND: CMR is considered the 'gold standard' for non-invasive LV and RV mass quantitation. This information is solely based on gradient-recalled echo (GRE) sequences while contrast dependent on intrinsic T1/T2 characteristics potentially offers superior image contrast between blood and myocardium. This study aims, for the first time in humans, to validate the SSFP approach using explanted hearts obtained from heart transplant recipients. Our objective is establish the correlation between and to validate steady-state free precession (SSFP) derived LV and RV mass vs. autopsy mass of hearts from cardiac transplants patients. METHODS: Over three-years, 58 explanted cardiomyopathy hearts were obtained immediately upon orthotopic heart transplantation from the OR. They were quickly cleaned, prepared and suspended in a saline-filled container and scanned ex vivo via SSFP-SA slices to define LV/RV mass. Using an automatic thresholding program, segmentation was achieved in combination with manual trimming (ATMT) of extraneous tissue incorporating 3D cardiac modeling performed by independent and blinded readers. The explanted hearts were then dissected with the ventricles surgically separated at the interventricular septum. Weights of the total heart not excluding papillary and trabecular myocardium, LV and RV were measured via high-fidelity scale. Linear regression and Bland-Altman plots were used to analyze the data. The intra-class correlation coefficient was used to assess intra-observer reliability. RESULTS: Of the total of 58 explanted hearts, 3 (6%) were excluded due to poor image quality leaving 55 patients (94%) for the final analysis. Significant positive correlations were found between total 3D CMR mass (450 ± 111 g) and total pathology mass (445 ± 116 g; r = 0.99, p < 0.001) as well as 3D CMR measured LV mass (301 ± 93 g) and the pathology measured LV mass (313 ± 96 g; r = 0.95, p < 0.001). Strong positive correlations were demonstrated between the 3D CMR measured RV mass (149 ± 46 g) and the pathology measured RV mass (128 ± 40 g; r = 0.76, p < 0.001). The mean bias between 3D-CMR and pathology measures for total mass, LV mass and RV mass were: 3.0 g, -16 g and 19 g, respectively. CONCLUSIONS: SSFP-CMR accurately determines total myocardial, LV and RV mass as compared to pathology weighed explanted hearts despite variable surgical removal of instrumentation (left and right ventricular assist devices, AICD and often apical core removals). Thus, this becomes the first-ever human CMR confirmation for SSFP now validating the distinction of 'gold standard'.
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Cardiomiopatías/diagnóstico , Ventrículos Cardíacos/patología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Cardiomiopatías/patología , Cardiomiopatías/cirugía , Femenino , Trasplante de Corazón , Ventrículos Cardíacos/cirugía , Humanos , Interpretación de Imagen Asistida por Computador , Modelos Lineales , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Tamaño de los Órganos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Background: Hypertensive disorders of pregnancy (HDP) can be classified into gestational hypertension, preeclampsia (PRE), and chronic hypertension with superimposed preeclampsia (SPE). Objectives: The purpose of this study was to retrospectively examine the echocardiographic differences in biventricular structure and function in 3 HDP groups of women in comparison to normotensive pregnant controls. Methods: Women with an echocardiogram during or within the first year of pregnancy were identified within our integrated health network. Exclusion criteria included age <18 years, diagnosis of pulmonary embolism, malignancy, autoimmune disease, and structural heart disease. Results: We identified a total of 706 subjects (cases: n = 427, normotensive controls: n = 279). Cases were divided into 3 groups: gestational hypertension (n = 57), PRE (n = 291), and SPE (n = 79). In adjusted analyses, echocardiographic parameters demonstrated a graded difference in left ventricular (LV) mass index, relative wall thickness, mitral inflow E, mitral inflow A, septal e', lateral e', E/e', left atrial volume index, tricuspid velocity, and lateral e' velocities with the most profound findings noted in the SPE group. Specifically, adjusted LV mass index (adjusted ß = 14.45, 95% CI: 9.00-19.90) and E/e' (adjusted ß = 2.97, 95% CI: 2.27-3.68) was highest in the SPE group in comparison to controls (P < 0.001). Conclusions: LV remodeling and diastolic filling abnormalities are more common in HDP and are most evident in SPE and PRE. Echocardiography during or immediately after pregnancy may be useful in these high-risk women to identify these abnormalities. The long-term implications of these echocardiographic abnormalities require further study.
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BACKGROUND AND AIM OF THE STUDY: Post-myocardial infarction (MI) mitral regurgitation (MR) is thought to be due to a passive, rather than active, remodeling of the mitral valve apparatus and its relationship with other cardiac structures that contribute to MR. Standard contrast-enhanced magnetic resonance (CMR) late gadolinium enhancement (LGE) may be sensitive to non-myocardial pathology involving the mitral valve leaflets. It was hypothesized that the presence of mitral valve enhancement (MVE) on LGE imaging in post-MI patients would be associated with an increased incidence of MR. METHODS: The presence or absence of MVE was noted in patients presenting for CMR with MI and non-MI indications requiring LGE. A chi-square analysis was performed for non-contiguous variables; SPSS (Chicago) software was utilized for the statistical analysis. RESULTS: Eighty-seven patients (54 males, 33 females) underwent LGE-CMR studies utilizing a 1.5 T GE scanner with MultiHance gadolinium contrast administration. LGE+ (present) was noted in 68 patients, and LGE- (absent) in 19 patients. Post-MI patterns of LGE+ were noted in 51 patients and LGE-in 36 patients; MVE+ was noted in 39 patients and MVE- in 48; and MR+ was present in 67 patients and absent (MR-) in 20 patients. MVE was observed chiefly in post-MI patients (33/51; 65%) and infrequently in non-post-MI patients (6/36; 17%; chi2 = 17.8, p < 0.001, power = 0.995). Further, MR was present more frequently in patients with MVE (36/39; 92%) compared to patients without MVE (31/48; 65%; chi2 = 7.8, p = 0.005, power = 0.814). CONCLUSION: MVE is present in a large number of post-MI patients but rarely in non-post-MI patients. Post-MI patients with, rather than without, MVE are far more likely to have MR. These observations suggest a specific but as-yet unknown reactive process that may contribute to mitral leaflet remodeling in post-MI patients, potentially contributing to an increased incidence of MR in post-MI patients.
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Imagen por Resonancia Cinemagnética/métodos , Insuficiencia de la Válvula Mitral/etiología , Válvula Mitral/patología , Infarto del Miocardio/complicaciones , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/epidemiología , Infarto del Miocardio/diagnóstico , Pronóstico , Estudios Retrospectivos , Ultrasonografía , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND AND AIM OF THE STUDY: Cardiac magnetic resonance (CMR) imaging generally allows a more accurate and valid quantification of cardiac function, mass and regurgitant volumes than echocardiography. Although recent technological advancements in CMR have made the evaluation of cardiac valves more reliable, no studies have yet been conducted to compare semi-quantitative grading (SQG) using CMR steady-state free precession (SSFP) sequences with quantitative grading (QG) based on stroke volumes and phase-velocity mapping (PVM). It is proposed that the SQG of cardiac valvular regurgitations based on CMR SSFP sequences is feasible, and highly correlative with standard CMR QG methods. METHODS: CMR data obtained between January 2007 and December 2011 was evaluated prospectively for valvular regurgitant lesions. Patients were included if they had right and left ventricular volumetrics based on CMR SSFP sequences and PVM across the aortic and pulmonic valves with reported regurgitant volumes and fractions. Patients were excluded if they had prosthetic valves, cardiac arrhythmias and intra-cardiac shunts. Regurgitant lesions were semi-quantitatively (visually) graded on a standard scale of 0 to 4 (trace, mild, moderate, moderate to severe, and severe) and compared with quantitative regurgitant fractions. Correlations were evaluated by Spearman's rho formula, and kappa for intra- and inter-observer variabilities were obtained on 30% of the study sample. RESULTS: A total of 97 patients (58 males, 39 females; average age 55 +/- 18 years) representing 134 valvular regurgitations [mitral (MR), aortic (AR), tricuspid (TR), and pulmonary (PR)] were analyzed by semiquantitative and quantitative methods. The regurgitant lesions included 44 mitral, 50 aortic, 29 tricuspid, and 11 pulmonary. The correlation between SQR versus QG yielded the following results: 0.67, p < 0.001 (MR, r = 0.66, p < 0.001; AR, r = 0.68, p < 0.002; TR, r = 0.68, p = 0.001; PR, r = 0.70, p = 0.017). The results for QG versus SQG accounting for clinically significant differences of +/- 1 grade for the group were as follows: 0.95, p < 0.001 (MR, r = 0.91, p < 0.001; AR, r = 0.96, p < 0.001; TR, r = 0.99, p < 0.001; PR, r = 0.93, p < 0.001). No discrepancy between surgical regurgitation was present (3+ versus 4+). Weighted kappa results were 0.67 and 0.61 for intra- and inter-observer variabilities. CONCLUSION: The visual assessment of cardiac regurgitant lesions is reliable, accurate and reproducible when compared to formal quantitative analysis via CMR. This confirms a robust role for CMR in assessing regurgitant lesions, particularly for surgical decision-making. These results were applicable to patients in sinus rhythm at the time of scanning.
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Insuficiencia de la Válvula Aórtica , Ecocardiografía , Válvulas Cardíacas/fisiopatología , Imagen por Resonancia Magnética , Insuficiencia de la Válvula Mitral , Insuficiencia de la Válvula Pulmonar , Insuficiencia de la Válvula Tricúspide , Adulto , Anciano , Insuficiencia de la Válvula Aórtica/diagnóstico , Insuficiencia de la Válvula Aórtica/fisiopatología , Técnicas de Imagen Cardíaca/métodos , Precisión de la Medición Dimensional , Ecocardiografía/métodos , Ecocardiografía/normas , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico , Insuficiencia de la Válvula Mitral/fisiopatología , Variaciones Dependientes del Observador , Insuficiencia de la Válvula Pulmonar/diagnóstico , Insuficiencia de la Válvula Pulmonar/fisiopatología , Índice de Severidad de la Enfermedad , Estadística como Asunto , Insuficiencia de la Válvula Tricúspide/diagnóstico , Insuficiencia de la Válvula Tricúspide/fisiopatologíaRESUMEN
Rupture risk assessment of abdominal aortic aneurysms (AAA) by means of biomechanical analysis is a viable alternative to the traditional clinical practice of using a critical diameter for recommending elective repair. However, an accurate prediction of biomechanical parameters, such as mechanical stress, strain, and shear stress, is possible if the AAA models and boundary conditions are truly patient specific. In this work, we present a complete fluid-structure interaction (FSI) framework for patient-specific AAA passive mechanics assessment that utilizes individualized inflow and outflow boundary conditions. The purpose of the study is two-fold: (1) to develop a novel semiautomated methodology that derives velocity components from phase-contrast magnetic resonance images (PC-MRI) in the infrarenal aorta and successfully apply it as an inflow boundary condition for a patient-specific fully coupled FSI analysis and (2) to apply a one-way-coupled FSI analysis and test its efficiency compared to transient computational solid stress and fully coupled FSI analyses for the estimation of AAA biomechanical parameters. For a fully coupled FSI simulation, our results indicate that an inlet velocity profile modeled with three patient-specific velocity components and a velocity profile modeled with only the axial velocity component yield nearly identical maximum principal stress (σ1), maximum principal strain (ε1), and wall shear stress (WSS) distributions. An inlet Womersley velocity profile leads to a 5% difference in peak σ1, 3% in peak ε1, and 14% in peak WSS compared to the three-component inlet velocity profile in the fully coupled FSI analysis. The peak wall stress and strain were found to be in phase with the systolic inlet flow rate, therefore indicating the necessity to capture the patient-specific hemodynamics by means of FSI modeling. The proposed one-way-coupled FSI approach showed potential for reasonably accurate biomechanical assessment with less computational effort, leading to differences in peak σ1, ε1, and WSS of 14%, 4%, and 18%, respectively, compared to the axial component inlet velocity profile in the fully coupled FSI analysis. The transient computational solid stress approach yielded significantly higher differences in these parameters and is not recommended for accurate assessment of AAA wall passive mechanics. This work demonstrates the influence of the flow dynamics resulting from patient-specific inflow boundary conditions on AAA biomechanical assessment and describes methods to evaluate it through fully coupled and one-way-coupled fluid-structure interaction analysis.
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Aneurisma de la Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/fisiopatología , Modelos Cardiovasculares , Anciano , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Rotura de la Aorta/etiología , Rotura de la Aorta/patología , Rotura de la Aorta/fisiopatología , Fenómenos Biomecánicos , Ingeniería Biomédica , Velocidad del Flujo Sanguíneo , Análisis de Elementos Finitos , Hemodinámica , Humanos , Angiografía por Resonancia Magnética , Masculino , Interpretación de Imagen Radiográfica Asistida por Computador , Factores de Riesgo , Tomografía Computarizada por Rayos XRESUMEN
Assessment of therapeutic interventions in patients with pulmonary arterial hypertension (PAH) suffers from several commonly encountered limitations: (1) patient studies are often too small and short-term to provide definitive conclusions, (2) there is a lack of a universal set of metrics to adequately assess therapy and (3) while clinical treatments focus on management of symptoms, there remain many cases of early loss of life in a seemingly arbitrary distribution. Here we provide a unified approach to assess right and left pressure relationships in PAH and pulmonary hypertension (PH) patients by developing linear models informed by the observation of Suga and Sugawa that pressure generation in the ventricle (right or left) approximately follows a single lobe of a sinusoid. We sought to identify a set of cardiovascular variables that either linearly or via a sine transformation related to systolic pulmonary arterial pressure (PAPs) and systemic systolic blood pressure (SBP). Importantly, both right and left cardiovascular variables are included in each linear model. Using non-invasively obtained cardiovascular magnetic resonance (CMR) image metrics the approach was successfully applied to model PAPs in PAH patients with an r2 of 0.89 (p < 0.05) and SBP with an r2 of 0.74 (p < 0.05). Further, the approach clarified the relationships that exist between PAPs and SBP separately for PAH and PH patients, and these relationships were used to distinguish PAH vs. PH patients with good accuracy (68%, p < 0.05). An important feature of the linear models is that they demonstrate that right and left ventricular conditions interact to generate PAPs and SBP in PAH patients, even in the absence of left-sided disease. The models predicted a theoretical right ventricular pulsatile reserve that in PAH patients was shown to be predictive of the 6â min walk distance (r2 = 0.45, p < 0.05). The linear models indicate a physically plausible mode of interaction between right and left ventricles and provides a means of assessing right and left cardiac status as they relate to PAPs and SBP. The linear models have potential to allow assessment of the detailed physiologic effects of therapy in PAH and PH patients and may thus permit cross-over of knowledge between PH and PAH clinical trials.
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BACKGROUND: Worsening tricuspid regurgitation (TR) after either permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD) implantation is an emerging clinical challenge. Early recognition of this entity is essential in guiding treatment. OBJECTIVE: This meta-analysis was designed to identify the overall incidence and patient-specific predictors of TR post-device implantation. METHODS: We searched electronic databases from inception to January 2023 for published studies that reported the incidence of TR worsening post-device implantation. The log odds ratio (OR) was used to summarize group differences. RESULTS: Our analysis included 29 studies with 66,590 participants. Patients who underwent device implantation (n = 1008) were significantly more likely to develop worsening TR than controls who did not undergo device implantation (n = 58,605) (OR 3.18; P < .01). In a total of 7777 patients, the pooled incidence of at least 1-grade worsening of TR post-device implantation was 24%. Worsening TR post-device implantation significantly increases mortality (hazard ratio 1.42; P = .02). Larger right atrial area (OR 1.11; P < .01) is significantly associated with an increased risk of worsening TR post-device implantation, while male patients are less likely to develop this complication than female patients (OR 0.74; P < .01). Importantly, there is no statistically significant difference between the type of implanted device (ICD vs PPM) and post-device implantation TR. Further, right ventricular dysfunction, pulmonary artery pressure, baseline mitral regurgitation, left ventricular ejection fraction, baseline atrial fibrillation, and age have no association with worsening TR post-device implantation. CONCLUSION: A substantial number of patients undergoing PPM or ICD implantation are at an increased risk of worsening TR. Importantly, in this largest review to date incorporating more than 66,000 subjects, worsening TR significantly increases mortality by greater than 140%, accordingly deserving more recognition and clinical attention in the current era.
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Fibrilación Atrial , Desfibriladores Implantables , Marcapaso Artificial , Insuficiencia de la Válvula Tricúspide , Humanos , Masculino , Femenino , Insuficiencia de la Válvula Tricúspide/diagnóstico , Insuficiencia de la Válvula Tricúspide/epidemiología , Insuficiencia de la Válvula Tricúspide/etiología , Desfibriladores Implantables/efectos adversos , Volumen Sistólico , Función Ventricular Izquierda , Marcapaso Artificial/efectos adversos , Fibrilación Atrial/complicaciones , Estudios RetrospectivosRESUMEN
Aims: Mitral Annular Disjunction (MAD) refers to embryologic fibrous separation between mitral annular ring and basal left ventricular myocardium. Since its original description, the role of MAD in arrhythmic mitral valve prolapse (MVP) has been the subject of active research. In this study we sought to assess prognostic and imaging characteristics of MVP patients with and without underlying MAD. Methods and results: Patients with posterior or bi-leaflet MVP were retrospectively identified via a review of all patients referred to our cardiac magnetic resonance (CMR) imaging laboratory from January 2015 to May 2022. MVP patients were further stratified by underlying MAD status. A total of 100 MVP patients undergoing CMR imaging (52 MVP patients with posterior MAD) were retrospectively identified with female comprising 55 % of the cohort. MVP patients with MAD were more likely to have an abnormal basal inferolateral/ papillary muscles LGE (51 % vs 21 %, p < 0.01). Posterior MAD longitudinal disjunction gap in 'mm' was a predictor of ventricular tachycardia (VT) [1.29, p = 0.01)]. Using ROC curve analysis, a disjunction gap of ≥ 4 mm was predictive of VT (AUC-0.71, p < 0.01), and incorporation of LGE in ROC model further improved AUC to 0.78 confirmed via Akaike information criterion (p < 0.01). Conclusion: Abnormal LGE involving basal inferolateral myocardium and papillary muscles may provide etiologic substrate for arrythmia in MVP patients.
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BACKGROUND: Pulmonary hypertension (PH) frequently co-exists in patients with severe aortic stenosis (AS). In this study, we sought to identify the implications of invasive pulmonary hemodynamics on major adverse cardiac events (MACE), biventricular function and NYHA functional class after transcatheter aortic valve replacement (TAVR). METHODS: Invasive hemodynamics via right heart catheterization (RHC) were performed pre-TAVR. Patients were stratified per mean PA pressure (mPAP), diastolic pulmonary gradient (DPG) and pulmonary vascular resistance (PVR), and followed at 1-month and 1-year intervals up to 6 years. MACE outcomes included cardiovascular death and heart failure hospitalizations post-TAVR. RESULTS: Among 215 patients, Kaplan-Meir estimates demonstrated an increased 1-year risk of MACE from 8% among those without pre-TAVR PH to 27% among patients with pre-existing PH. Specifically, the MACE risk was 32% among PH patients with PVR ≥ 3WU (p = .04) and 53% among PH patients with DPG ≥ 7 mm Hg (p < .01). On univariate Cox regression, RV stroke work index (RVSWI) (HR,1.02; p = .02), and pulmonary hemodynamic index (PHI) (HR,1.27; p = .047) were identified as additional predictors of MACE post-TAVR. On multivariable Cox regression analysis, SvO2 (HR, 0.95; p = .01) and PVR (HR, 1.2; p = .04) were demonstrated as predictive of MACE post-TAVR. A significant improvement in LVEF (2-Factor ANOVA, p < .01) and RV fractional area change (RVFAC%) (p < .01) was noted as assessed at baseline, 1-month and 1-year follow up post-TAVR. There was a significant interaction between pre-TAVR PH status and time post procedure with respect to NYHA functional class (p = .03), that is, the manner and degree of change in NYHA class over time depended on pre-TAVR PH status. CONCLUSIONS: Defining invasive pulmonary hemodynamics, such as mPAP, PVR, and DPG among patients with severe AS undergoing TAVR has significant prognostic implications. Routine risk stratification by utilizing invasive hemodynamics can better identify patients who will have functional improvement and improved outcomes post-TAVR.
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Estenosis de la Válvula Aórtica , Hipertensión Pulmonar , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Pronóstico , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/cirugía , Resultado del Tratamiento , Hemodinámica , Hipertensión Pulmonar/complicaciones , Válvula Aórtica , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
Little is known about the psychological and physiological impacts of moral injury within organizational contexts such as Internet Child Abuse Teams (hereafter abbreviated to ICAT), who are repeatedly exposed to trauma through viewing and grading graphic images of children being sexually abused. The aims of the current research were to explore the key features of, and contributing factors to, moral injury and trauma as experienced by Internet Child Abuse Teams, how these manifested and how these factors can be mitigated. Six participants were recruited from ICATs located at two police constabularies. Data were gathered using semi-structured interviews and analysed using interpretative phenomenological analysis. Findings indicated that the moral injury experienced by the participants was predominantly attributable to repeated exposure to traumatising images, with too little decompression time. Dysfunctional coping mechanisms, most commonly substance misuse, cognitive avoidance of distressing thoughts and emotional numbing, amplified the psychological and physical symptoms of anxiety. For many ICAT investigators, such tactics were attempts to manage the moral violations arising from their work and experienced as moral injury. These findings will be used to inform psychological review systems and interventions within policing.
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Australian wild deer populations have significantly expanded in size and distribution in recent decades. Due to their role in pathogen transmission, these deer populations pose a biosecurity risk to the livestock industry. However, little is known about the infection status of wild deer in Australia. The intestinal parasite Entamoeba bovis has been previously detected in farm and wild ruminants worldwide, but its epidemiology and distribution in wild ruminants remain largely unexplored. To investigate this knowledge gap, faecal samples of wild deer and domestic cattle from south-eastern Australia were collected and analysed for the presence of Entamoeba spp. using PCR and phylogenetic analysis of the conserved 18S rRNA gene. E. bovis parasites were detected at high prevalence in cattle and wild deer hosts, and two distinct Entamoeba ribosomal lineages (RLs), RL1 and RL8, were identified in wild deer. Phylogenetic analysis further revealed the existance of a novel Entamoeba species in sambar deer and a novel Entamoeba RL in fallow deer. While we anticipated cross-species transmission of E. bovis between wild deer and cattle, the data generated in this study demonstrated transmission is yet to occur in Australia. Overall, this study has identified novel variants of Entamoeba and constitutes the first report of Entamoeba in fallow deer and sambar deer, expanding the host range of this parasite. Epidemiological investigations and continued surveillance of Entamoeba parasites in farm ruminants and wild animals will be required to evaluate pathogen emergence and transmission to livestock.
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Ciervos , Entamoeba , Parásitos , Animales , Animales Salvajes , Australia/epidemiología , Bovinos , Ciervos/parasitología , Entamoeba/genética , Ganado , Filogenia , RumiantesRESUMEN
In 2019/2020, Australia experienced a severe bushfire event, with many tens of thousands of livestock killed or euthanized. Little systematic research has occurred to understand livestock bushfire injuries, risk factors for injury, or how to make decisions about management of bushfire-injured livestock. Addressing this research gap is important as there is an increasing bushfire incidence globally. This paper presents qualitative research findings about bushfire-injured and killed livestock in the south-east of Australia after the 2019/2020 Australian bushfires. We describe observed pathology, treatments used, and risk factors for injury, then use thematic analysis to understand decision making about managing fire-injured livestock. Livestock injured by the fires showed pathology predominantly associated with the common integument (feet, hooves and skin) and signs of acute respiratory damage. It could take several days for the full extent of burns to become apparent, leaving prognostic doubt. Treatment strategies included immediate euthanasia, salvage slaughter, retention for later culling, treatment and recovery on farm, hospitalization and intensive treatment, or no intervention. Risk factors reported for livestock injury included lack of warnings about an impending fire, the type and amount of vegetation around livestock and the weather conditions on the day the fire reached livestock. Moving stock to an area with little vegetation before fire arrived was seen as protective. Decision making regarding injured livestock appeared influenced by three main themes: (1) observations on the severity of pathology, clinical signs and level of prognostic doubt, (2) pre-existing beliefs about animal welfare (responsibility to minimize unnecessary suffering) and (3) assumptions about the future. The management of livestock was largely appropriate due to the rapid provision of veterinary expertise. However, it is likely that some injured livestock were euthanized due to conservative veterinary advice driven by a lack of opportunity to re-assess stock, with impacts on farmers. In future, resourcing regular revisits of injured livestock to manage risks of gradual progression of burn pathology may facilitate more accurate prognostic assessment, provided injured animals can receive appropriate pain relief. In addition, a more comprehensive burns classification system linked to prognosis that can be rapidly applied in the field may assist assessments.