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1.
Undersea Hyperb Med ; 48(1): 73-80, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33648036

RESUMO

Venous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubble-counting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this automation relies on the selection of a frame during late ventricular diastole (LVD) for each cardiac cycle of the recording. Since electrocardiograms (ECG) are not always recorded in field experiments, here we propose a fully automated method for LVD frame selection based on regional intensity minimization. The algorithm is tested on 20 previously acquired echocardiography recordings (from the original bubble-counting publication), half of which were acquired at rest (Rest) and the other half after leg flexions (Flex). From the 7,140 frames analyzed, sensitivity was found to be 0.913 [95% CI: 0.875-0.940] and specificity 0.997 [95% CI: 0.996-0.998]. The method's performance is also compared to that of random chance selection and found to perform significantly better (p≺0.0001). No trend in algorithm performance was found with respect to VGE counts, and no significant difference was found between Flex and Rest (p>0.05). In conclusion, full automation of LVD frame selection for the purpose of bubble counting in post-dive echocardiography has been established with excellent accuracy, although we caution that high quality acquisitions remain paramount in retaining high reliability.


Assuntos
Algoritmos , Diagnóstico por Computador/métodos , Mergulho/fisiologia , Ecocardiografia/métodos , Embolia Aérea/diagnóstico por imagem , Função Ventricular/fisiologia , Doença da Descompressão/diagnóstico por imagem , Diagnóstico por Computador/estatística & dados numéricos , Diástole/fisiologia , Ecocardiografia/estatística & dados numéricos , Ventrículos do Coração/diagnóstico por imagem , Humanos , Contração Miocárdica/fisiologia , Sensibilidade e Especificidade
2.
Sci Rep ; 10(1): 22298, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339836

RESUMO

An understanding of left ventricle (LV) mechanics is fundamental for designing better preventive, diagnostic, and treatment strategies for improved heart function. Because of the costs of clinical and experimental studies to treat and understand heart function, respectively, in-silico models play an important role. Finite element (FE) models, which have been used to create in-silico LV models for different cardiac health and disease conditions, as well as cardiac device design, are time-consuming and require powerful computational resources, which limits their use when real-time results are needed. As an alternative, we sought to use deep learning (DL) for LV in-silico modeling. We used 80 four-chamber heart FE models for feed forward, as well as recurrent neural network (RNN) with long short-term memory (LSTM) models for LV pressure and volume. We used 120 LV-only FE models for training LV stress predictions. The active material properties of the myocardium and time were features for the LV pressure and volume training, and passive material properties and element centroid coordinates were features of the LV stress prediction models. For six test FE models, the DL error for LV volume was 1.599 ± 1.227 ml, and the error for pressure was 1.257 ± 0.488 mmHg; for 20 LV FE test examples, the mean absolute errors were, respectively, 0.179 ± 0.050 for myofiber, 0.049 ± 0.017 for cross-fiber, and 0.039 ± 0.011 kPa for shear stress. After training, the DL runtime was in the order of seconds whereas equivalent FE runtime was in the order of several hours (pressure and volume) or 20 min (stress). We conclude that using DL, LV in-silico simulations can be provided for applications requiring real-time results.


Assuntos
Coração/fisiopatologia , Memória de Curto Prazo/fisiologia , Miocárdio/patologia , Função Ventricular/fisiologia , Simulação por Computador , Análise de Elementos Finitos , Ventrículos do Coração/fisiopatologia , Humanos , Modelos Cardiovasculares , Infarto do Miocárdio/fisiopatologia , Redes Neurais de Computação , Estresse Mecânico , Função Ventricular Esquerda/fisiologia
3.
PLoS One ; 15(12): e0244312, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33338081

RESUMO

BACKGROUND: Few studies demonstrate delayed recovery after exercise in children and adults with heart disease. We assess the recovery patterns of gas exchange parameters and heart rate (HR) in children with repaired Tetralogy of Fallot (rToF) compared to healthy peers and investigate the correlation with ventricular function and QRS duration. METHODS: 45 children after rToF and 45 controls performed a maximal incremental cardiopulmonary exercise test. In the subsequent recovery period, patterns of VO2, VCO2 and HR were analysed. Half-life time (T1/2) of the exponential decay and drop per minute (Recmin) were compared between groups. In the rToF group, correlations were examined between the recovery parameters and QRS-duration and ventricular function, described by fractional shortening (FS) and tricuspid annular plane systolic excursion (TAPSE) measured at baseline prior to exercise. RESULTS: Recovery of VO2 and VCO2 was delayed in rToF patients, half-life time values were higher compared to controls (T1/2VO2 52.51 ±11.29 s vs. 44.31 ± 10.47 s; p = 0.001 and T1/2VCO2 68.28 ± 13.84 s vs. 59.41 ± 12.06 s; p = 0.002) and percentage drop from maximal value was slower at each minute of recovery (p<0.05). Correlations were found with FS (T1/2VO2: r = -0.517; p<0.001; Rec1minVO2: r = -0.636, p<0.001; Rec1minVCO2: r = -0.373, p = 0.012) and TAPSE (T1/2VO2: r = -0.505; p<0.001; Rec1minVO2: r = -0.566, p<0.001; T1/2VCO2: r = -0.466; p = 0.001; Rec1minVCO2: r = -0.507, p<0.001), not with QRS-duration. No difference was found in HR recovery between patients and controls. CONCLUSIONS: Children after rToF show a delayed gas exchange recovery after exercise. This delay correlates to ventricular function, demonstrating its importance in recovery after physical activity.


Assuntos
Exercício Físico/fisiologia , Recuperação de Função Fisiológica/fisiologia , Tetralogia de Fallot/reabilitação , Adolescente , Criança , Teste de Esforço , Terapia por Exercício/métodos , Tolerância ao Exercício/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Estudos Retrospectivos , Tetralogia de Fallot/fisiopatologia , Tetralogia de Fallot/cirurgia , Disfunção Ventricular Direita/fisiopatologia , Função Ventricular/fisiologia , Função Ventricular Direita/fisiologia
4.
PLoS One ; 15(10): e0239553, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33027252

RESUMO

Melanopic stimuli trigger diverse non-image-forming effects. However, evidence of a melanopic contribution to acute effects on alertness and performance is inconclusive, especially under common lighting situations. Effects on cognitive performance are likely mediated by effort-related physiological changes. We assessed the acute effects of lighting in three scenarios, at two times of day, on effort-related changes to cardiac contraction as indexed by the cardiac pre-ejection period (PEP). In a within-subject design, twenty-seven participants performed a cognitive task thrice during a morning and a late-afternoon session. We set the lighting at 500 lux in all three lighting scenarios, measured horizontally at the desk level, but with 54 lux, 128 lux, or 241 lux melanopic equivalent daylight illuminance at the eye level. Impedance cardiography and electrocardiography measurements were used to calculate PEP, for the baseline and task period. A shorter PEP during the task represents a sympathetic heart activation and therefore increased effort. Data were analysed with linear mixed-effect models. PEP changes depended on both the light scene and time of day (p = 0.01 and p = 0.002, respectively). The highest change (sympathetic activation) occurred for the medium one of the three stimuli (128 lux) during the late-afternoon session. However, effect sizes for the singular effects were small, and only for the combined effect of light and time of day middle-sized. Performance scores or self-reported scores on alertness and task demand did not change with the light scene. In conclusion, participants reached the same performance most efficiently at both the highest and lowest melanopic setting, and during the morning session. The resulting U-shaped relation between melanopic stimulus intensity and PEP is likely not dependent solely on intrinsic ipRGC stimuli, and might be moderated by extrinsic cone input. Since lighting situations were modelled according to current integrative lighting strategies and real-life indoor light intensities, the result has implications for artificial lighting in a work environment.


Assuntos
Valva Aórtica/fisiologia , Iluminação , Função Ventricular/fisiologia , Adulto , Cardiografia de Impedância , Eletrocardiografia , Feminino , Frequência Cardíaca , Humanos , Masculino , Contração Miocárdica , Sonolência , Análise e Desempenho de Tarefas , Temperatura , Adulto Jovem
5.
PLoS One ; 15(8): e0238045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857803

RESUMO

The mean systemic filling pressure (MSFP) represents an interaction between intravascular volume and global cardiovascular compliance (GCC). Intravascular volume expansion using fluid resuscitation is the most frequent intervention in intensive care and emergency medicine for patients in shock and with haemodynamic compromise. The relationship between dynamic changes in MSFP, GCC and left ventricular compliance is unknown. We conducted prospective interventional pilot study following euthanasia in post cardiotomy adult sheep, investigating the relationships between changes in MSFP induced by rapid intravascular filling with fluids, global cardiovascular compliance and left ventricular compliance. This pilot investigation suggested a robust correlation between a gradual increase in the intravascular stressed volume from 0 to 40 ml/kg and the MSFP r = 0.708 95% CI 0.435 to 0.862, making feasible future prospective interventional studies. Based on the statistical modelling from the pilot results, we expect to identify a strong correlation of 0.71 ± 0.1 (95% CI) between the MSFP and the stressed intravascular volume in a future study.


Assuntos
Volume Sanguíneo , Hemodinâmica , Animais , Ponte Cardiopulmonar , Ecocardiografia , Feminino , Ventrículos do Coração/fisiopatologia , Modelos Animais , Projetos Piloto , Estudos Prospectivos , Ovinos , Estresse Fisiológico , Função Ventricular/fisiologia
6.
Am J Hum Genet ; 106(6): 764-778, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32386560

RESUMO

Sudden cardiac death is responsible for half of all deaths from cardiovascular disease. The analysis of the electrophysiological substrate for arrhythmias is crucial for optimal risk stratification. A prolonged T-peak-to-Tend (Tpe) interval on the electrocardiogram is an independent predictor of increased arrhythmic risk, and Tpe changes with heart rate are even stronger predictors. However, our understanding of the electrophysiological mechanisms supporting these risk factors is limited. We conducted genome-wide association studies (GWASs) for resting Tpe and Tpe response to exercise and recovery in ∼30,000 individuals, followed by replication in independent samples (∼42,000 for resting Tpe and ∼22,000 for Tpe response to exercise and recovery), all from UK Biobank. Fifteen and one single-nucleotide variants for resting Tpe and Tpe response to exercise, respectively, were formally replicated. In a full dataset GWAS, 13 further loci for resting Tpe, 1 for Tpe response to exercise and 1 for Tpe response to exercise were genome-wide significant (p ≤ 5 × 10-8). Sex-specific analyses indicated seven additional loci. In total, we identify 32 loci for resting Tpe, 3 for Tpe response to exercise and 3 for Tpe response to recovery modulating ventricular repolarization, as well as cardiac conduction and contraction. Our findings shed light on the genetic basis of resting Tpe and Tpe response to exercise and recovery, unveiling plausible candidate genes and biological mechanisms underlying ventricular excitability.


Assuntos
Eletrocardiografia , Exercício Físico/fisiologia , Estudo de Associação Genômica Ampla , Função Ventricular/genética , Adulto , Idoso , Feminino , Loci Gênicos/genética , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Descanso/fisiologia , Caracteres Sexuais , Reino Unido , Função Ventricular/fisiologia
7.
Am J Physiol Heart Circ Physiol ; 318(5): H1059-H1067, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32142380

RESUMO

The spatiotemporal features of normal in vivo cardiac motion are well established. Longitudinal velocity has become a focus of diastolic function (DF) characterization, particularly the tissue Doppler e'-wave, manifesting in early diastole when the left ventricle (LV) is a mechanical suction pump (dP/dV < 0). To characterize DF and elucidate mechanistic features, several models have been proposed and have been previously compared algebraically, numerically, and in their ability to fit physiological velocity data. We analyze two previously noncompared models of early rapid-filling lengthening velocity (Doppler e'-wave): parametrized diastolic filling (PDF) and force balance model (FBM). Our initial numerical experiments sampled FBM-generated e'(t) contours as input to determine PDF model predicted fit. The resulting exact numerical agreement [standard error of regression (SER) = 9.06 × 10-16] was not anticipated. Therefore, we analyzed all published FBM-generated e'(t) contours and observed identical agreement. We re-expressed FBM's algebraic expressions for e'(t) and observed for the first time that model-based predictions for lengthening velocity by the FBM and the PDF model are mathematically identical: e'(t) = γe-αtsinh(ßt), thereby providing exact algebraic relations between the three PDF parameters and the six FBM parameters. Previous pioneering experiments have independently established the unique determinants of e'(t) to be LV relaxation, restoring forces (stiffness), and load. In light of the exact intermodel agreement, we conclude that the three PDF parameters, relaxation, stiffness (restoring forces), and load, are unique determinants of DF and e'(t). Thus, we show that only the PDF formalism can compute the three unique, independent, physiological determinants of long-axis LV myocardial velocity from e'(t).NEW & NOTEWORTHY We show that two separate, independently derived physiological (kinematic) models predict mathematically identical expressions for LV-lengthening velocity (Doppler e'-wave), indicating that damped harmonic oscillatory motion is a physiologically accurate model of diastolic function. Although both models predict the same "overdamped" velocity contour, only one model solves the "inverse problem" and generates unique, lumped parameters of relaxation, stiffness (restoring force), and load from the e'-wave.


Assuntos
Diástole , Hemodinâmica , Modelos Cardiovasculares , Função Ventricular/fisiologia , Humanos
8.
PLoS One ; 15(3): e0230134, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160262

RESUMO

BACKGROUND: Recent studies concerning left ventricular noncompaction (LVNC) suggest that the extent of left ventricular (LV) hypertrabeculation has no impact on prognosis. The variety of methods of LV noncompacted myocardial mass (NCM) assessment may influence the results. Hence, we compared two methods of NCM estimation: largely observer-independent Hautvast's(H) computed algorithm-based approach and commonly used Jacquier's(J) method, and their associations with LV end-diastolic volume (EDV) and ejection fraction (EF). METHODS: Cardiac magnetic resonance images of 77 persons (45±17yo) - 42 LVNC, 15 non-ischemic dilative cardiomyopathy, 20 control group were analyzed. LVNC patients were divided into the subgroup with normal (LVNCN) and high EDV (LVNCDCM). NCM and total left ventricular mass (LVM) were estimated by Hautvast's [excluding intertrabecular blood (ITB) and including papillary muscles (PMs) into NCM] and Jacquier's approach (including ITB and PMs, if unclearly distinguished, into NCM). RESULTS: The cut-off value of NCM for LVNC diagnosis was 22% (AUC 0.933) for NCMH/LVMH and 26% (AUC 0.883) for NCMJ/LVMJ. Inter- and intra-observer variability (estimated by coefficient of variation [CoV] and intraclass correlation coefficient [ICC]) of NCMH/LVMH appeared better than of NCMJ/LVMJ (CoV 4.3%, ICC 0.981 and CoV 4.9%, ICC 0.978; respectively for NCMH/LVMH, while for NCMJ/LVMJ: CoV 19.7%, ICC 0.15 and CoV 12.9%, ICC 0.504). In LVNCN subgroup, the correlation between EDV and NCMH was stronger than NCMJ (r = 0.677, p<0.001 vs. r = 0.480, p = 0.038; respectively). In LVNC the EDV correlated with NCMH/LVMH (r = 0.391, p<0.01), but not with NCMJ/LVMJ. In the overall group a relationship was present between EF and NCMH/LVMH (r = -0.449, p<0.001), but not NCMJ/LVMJ. Only NCMH/LVMH explained the variability of EDV (b 0.434, p<0.001). CONCLUSIONS: Choosing a method of NCM assessment that is less observer-dependent might increase the reliability of results. The impact of method selection on the LV parameters and cut-off values for hypertrabeculation should be further investigated.


Assuntos
Ventrículos do Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imagem Cinética por Ressonância Magnética/métodos , Adulto , Idoso , Feminino , Cardiopatias Congênitas/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular/fisiologia , Função Ventricular Esquerda/fisiologia
10.
Clinics (Sao Paulo) ; 75: e1293, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31967282

RESUMO

Exercising prior to experimental infarction may have beneficial effects on the heart. The objective of this study was to analyze studies on animals that had exercised prior to myocardial infarction and to examine any benefits through a systematic review and meta-analysis. The databases MEDLINE, Google Scholar, and Cochrane were consulted. We analyzed articles published between January 1978 and November 2018. From a total of 858 articles, 13 manuscripts were selected in this review. When animals exercised before experimental infarction, there was a reduction in mortality, a reduction in infarct size, improvements in cardiac function, and a better molecular balance between genes and proteins that exhibit cardiac protective effects. Analyzing heart weight/body weight, we observed the following results - Mean difference 95% CI - -0.02 [-0.61,0.57]. Meta-analysis of the infarct size (% of the left ventricle) revealed a statistically significant decrease in the size of the infarction in animals that exercised before myocardial infarction, in comparison with the sedentary animals -5.05 [-7.68, -2.40]. Analysis of the ejection fraction, measured by echo (%), revealed that animals that exercised before myocardial infarction exhibited higher and statistically significant measures, compared with sedentary animals 8.77 [3.87,13.66]. We conclude that exercise performed prior to experimental myocardial infarction confers cardiac benefits to animals.


Assuntos
Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Condicionamento Físico Animal , Função Ventricular/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Coração , Ventrículos do Coração/fisiopatologia , Masculino , Camundongos , Modelos Cardiovasculares , Ratos , Ratos Sprague-Dawley , Ratos Wistar
11.
Am J Obstet Gynecol ; 222(6): 604.e1-604.e10, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31954157

RESUMO

BACKGROUND: Over the years, there has been an increasing interest in the assessment of maternal hemodynamic responses during pregnancy. With the use of both noninvasive devices and/or maternal echocardiography, it has been shown that mothers who have pregnancy complications have altered hemodynamics compared with those who have uncomplicated pregnancies. It also has been suggested that preexisting maternal cardiac changes might drive the development of complications in pregnancy that are associated with impaired placentation. To understand, however, this potential link in complicated pregnancies, it is important to clarify whether placental function is associated with maternal cardiac functional indices in normal pregnancies. OBJECTIVE: To determine whether placental function, perfusion, and fetal weight are associated with maternal cardiac hemodynamic responses at 35-36 weeks of gestation in normal pregnancies. STUDY DESIGN: Prospective screening of women attending Kings' College Hospital for routine hospital visit at 35-37 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure, uterine artery pulsatility index, sonographic estimated fetal weight, and serum placental growth factor and soluble fms-like tyrosine kinase 1. We also performed maternal echocardiogram to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function, including global longitudinal systolic function and left ventricular mass indexed to body surface area. RESULTS: We studied 1386 women. Maternal characteristics were associated with both maternal hemodynamics and functional and structural indices. Uterine artery pulsatility index was associated with left ventricular mass (P=.03) and global longitudinal systolic function (P=.017). There were significant nonlinear associations between placental growth factor and cardiac output and peripheral vascular resistance (P<.001 for both) and between soluble fms-like tyrosine kinase 1 and peripheral vascular resistance (P=.018). Estimated fetal weight was associated with maternal cardiac output (mean increase=0.186, 95% confidence interval, 0.133-0.238, P<.001) and peripheral vascular resistance (mean decrease=-0.164, 95% confidence interval, -0.217 to -0.111, P<.001). No association was noted between placental and fetal parameters and maternal cardiac functional and structural indices. In multivariable analysis, placental growth factor remained strongly associated with maternal cardiac output and peripheral vascular resistance (P=.002 for both) over and above maternal characteristics and estimated fetal weight. Estimated fetal weight was associated with left ventricular mass (0.102, 95% confidence interval, 0.044-0.162, P=.001). CONCLUSION: The results of this study suggest a strong link between maternal hemodynamic responses and fetoplacental needs across the whole spectrum in normal pregnancies. These findings would also indicate that to diagnose maternal cardiac dysfunction in pregnancies complicated by impaired placentation a more extensive echocardiographic assessment might be needed rather than relying on hemodynamics which are strongly associated with fetoplacental indices.


Assuntos
Pressão Arterial/fisiologia , Débito Cardíaco/fisiologia , Peso Fetal/fisiologia , Fator de Crescimento Placentário/metabolismo , Artéria Uterina/diagnóstico por imagem , Resistência Vascular/fisiologia , Adulto , Ecocardiografia , Ecocardiografia Doppler , Feminino , Idade Gestacional , Ventrículos do Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Placenta/diagnóstico por imagem , Placenta/fisiologia , Gravidez , Terceiro Trimestre da Gravidez , Fluxo Pulsátil , Ultrassonografia Doppler , Ultrassonografia Pré-Natal , Artéria Uterina/fisiologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Função Ventricular/fisiologia
12.
Am J Physiol Heart Circ Physiol ; 318(3): H534-H546, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31951472

RESUMO

Computational modeling based on experimental data remains an important component in cardiac electrophysiological research, especially because clinical data such as human action potential (AP) dynamics are scarce or limited by practical or ethical concerns. Such modeling has been used to develop and test a variety of mechanistic hypotheses, with the majority of these studies involving the rate dependence of AP duration (APD) including APD restitution and conduction velocity (CV). However, there is very little information regarding the complex dynamics at the boundary of repolarization (or refractoriness) and reexcitability. Here, we developed a "minimal" ionic model of the human AP, based on in vivo human monophasic AP (MAP) recordings obtained during clinical programmed electrical stimulation (PES) to address the progressive decrease in AP take-off potential (TOP) and associated CV slowing seen during three tightly spaced extrastimuli. Recent voltage-clamp data demonstrating the effect of intracellular calcium on sodium current availability were incorporated and were required to reproduce large (>15 mV) elevations in take-off potential and progressive encroachment. Introducing clinically observed APD gradients into the model enabled us to replicate the dynamic response to PES in patients leading to conduction block and reentry formation for the positive, but not the negative, APD gradient. Finally, we modeled the dynamics of reentry and show that spiral waves follow a meandering trajectory with a period of ~180 ms. We conclude that our model reproduces a variety of electrophysiological behavior including the response to sequential premature stimuli and provides a basis for studies of the initiation of reentry in human ventricular tissue.NEW & NOTEWORTHY This work presents a new model of the action potential of the human which reproduces the complex dynamics during premature stimulation in patients.


Assuntos
Potenciais de Ação/fisiologia , Simulação por Computador , Modelos Cardiovasculares , Miócitos Cardíacos/fisiologia , Função Ventricular/fisiologia , Arritmias Cardíacas/fisiopatologia , Estimulação Elétrica , Frequência Cardíaca/fisiologia , Ventrículos do Coração/fisiopatologia , Humanos
14.
Clin Physiol Funct Imaging ; 40(1): 30-36, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31578827

RESUMO

PURPOSE: To investigate diastolic and systolic patterns of segmental and transmural rest perfusion of the left ventricle (LV) in normal subjects (NS) undergoing third-generation dual-source cardiac computed tomography (CCT). METHODS: Forty consecutive NS, with normal coronary arteries and cardiac chambers both anatomically and functionally on the basis of CCT, were retrospectively enrolled in the study. Relative normalized myocardial attenuation density (rnMAD) and transmural perfusion ratio (TPR) were calculated in diastole and systole for each segment and layer of the LV and then pooled into territories. RESULTS: Statistical analysis showed that sub-endocardial rnMAD was significantly higher than intra-myocardial and sub-epicardial for all myocardial territories both in systolic and diastolic phases (P<0·001). Basal and mid-ventricular rnMAD were higher than apical for all myocardial layers (P<0·001). Septum displayed higher rnMAD in intra-myocardium and sub-epicardium (179 ± 61 and 170 ± 59 in diastole and 172 ± 60 and 166 ± 58 in systole, respectively) than the anterior, lateral and inferior wall (P<0·001). Diastolic and systolic TPR were significantly different for the anterior and lateral wall (P<0·001), while septal TPR (1·06 ± 0·06 in diastole and 1·05 ± 0·06 in systole, respectively) was the lowest as compared to other territories' TPR. Finally, basal, mid-ventricular and apical TPR showed a significant linear trend with basal lower than mid-ventricular and apical values. CONCLUSION: Inter-territory and inter-layer myocardial perfusion differences can be accurately assessed with CCT in NS. This assessment is the basic step to further evaluate abnormal rest perfusion patterns in ischaemic and non-ischaemic diseases.


Assuntos
Circulação Coronária/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Função Ventricular/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
ASAIO J ; 66(1): 55-63, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30893130

RESUMO

This article presents a primed left ventricle heart perfusion method to generate physiologic aortic pressure (AoP) and perform functional assessment. Isolated hearts of male Yorkshire pigs were used to study the hemodynamic behaviors of AoPs generated in the primed left ventricle heart perfusion (n = 6) and conventional (zero-loaded left ventricle) Langendorff perfusion (n = 6). The measurement results show that left ventricular pressure generated in the primed left ventricle heart perfusion is a determinant of physiologic AoP (i.e. systolic and diastolic pressures within physiologic range). The aortic pulse pressure (systolic pressure = 124.5 ± 1.7 mm Hg, diastolic pressure = 87.8 ± 0.9 mm Hg, aortic pulse pressure = 36.7 ± 2.6 mm Hg) from the primed left ventricle heart perfusion represents close match with the in vivo physiologic data. The volume in the left ventricle remains constant throughout the primed left ventricle heart perfusion, which allows us to perform isovolumetric left ventricular pressure measurement in ex vivo heart perfusion (EVHP). Left ventricular contractility measurements (maximum and minimum rates of left ventricular pressure change) were derived for cardiac assessment. In summary, the proposed primed left ventricle heart perfusion method is able to create physiologic AoP and enables left ventricular functional assessment in EVHP in porcine hearts.


Assuntos
Pressão Arterial/fisiologia , Preparação de Coração Isolado , Perfusão/instrumentação , Perfusão/métodos , Função Ventricular/fisiologia , Animais , Pressão Sanguínea/fisiologia , Coração/fisiologia , Ventrículos do Coração , Hemodinâmica/fisiologia , Preparação de Coração Isolado/instrumentação , Preparação de Coração Isolado/métodos , Masculino , Suínos
16.
J Vet Intern Med ; 34(1): 45-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31875342

RESUMO

BACKGROUND: Spectral Doppler assessment of hepatic veins may provide information on heart function. HYPOTHESIS/OBJECTIVES: To assess the normal pattern of hepatic venous flow using spectral Doppler ultrasound examination; to correlate this information with structural and functional variables of the right ventricle (RV), and to analyze the impact of age, sex, body weight quartiles, heart rate, cardiac rhythm, and systolic arterial pressure on the results in healthy dogs. ANIMALS: Sixty-five healthy dogs. METHODS: Cross-sectional observational study. The direction and maximum velocity of each of the 4 possible components of venous flow were determined from pulsed-wave Doppler examination of the hepatic veins. In addition, structural and functional parameters (TAPSE, longitudinal strain, FAC%, S', Et /At, and E't / A't ) of the RV were evaluated. RESULTS: The same phase patterns for different waves were seen in all animals: A and V were retrograde waves, and S and D were anterograde waves. The velocity of the spectral waves increased with body weight (P < .05) and could be correlated with functional indices of the RV. A significant difference was found when comparing morphometric indices with body weight quartiles (P < .05). In addition, intra-and inter-observer assessments showed low variability. The mean duration of the examinations was 5.2 minutes. CONCLUSIONS AND CLINICAL IMPORTANCE: Hepatic spectral Doppler findings can be correlated with systolic and diastolic indices of the RV and vary with body weight.


Assuntos
Cães/anatomia & histologia , Ventrículos do Coração/diagnóstico por imagem , Veias Hepáticas/diagnóstico por imagem , Fígado/irrigação sanguínea , Ultrassonografia Doppler/veterinária , Função Ventricular/fisiologia , Envelhecimento , Animais , Tamanho Corporal , Estudos Transversais , Feminino , Masculino
17.
Sci Rep ; 9(1): 18541, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811258

RESUMO

Previous studies suggested an association between heart failure (HF) and hepatic disorders. Liver function parameters have been shown to predict outcome in HF with reduced ejection fraction, but their impact in HF with preserved ejection fraction (HFpEF) has not yet been investigated. Between January 2011 and February 2017, 274 patients with confirmed HFpEF were enrolled (age 71.3 ± 8.4 years, 69.3% female) in a prospective registry. During a median follow-up of 21.5 ± 18.6 months, 97 patients (35.4%) reached the combined endpoint defined as hospitalization due to HF and/ or death from any cause. By multivariable cox regression, serum gamma-glutamyltransferase (GT) was independently associated with outcome (Hazard Ratio (HR) 1.002, p = 0.004) along with N-terminal pro brain natriuretic peptide (HR 2.213, p = 0.001) and hemoglobin (HR 0.840, p = 0.006). Kaplan-Meier analysis showed that patients with serum gamma-GT levels above a median of 36 U/L had significantly more events as compared to the remainder of the group (log-rank p = 0.012). By multivariable logistic regression, higher early mitral inflow velocity/ mitral peak velocity of late filling (Odds Ratio (OR) 2.173, p = 0.024), higher right atrial (RA) pressure (OR 1.139, p < 0.001) and larger RA diameter (OR 1.070, p = 0.001) were independently associated with serum gamma-GT > 36 U/L. Serum levels of gamma-GT are associated with both left and right-sided cardiac alterations and may serve as a simple tool for risk prediction in HFpEF, especially when further diagnostic modalities are not available.


Assuntos
Insuficiência Cardíaca/mortalidade , gama-Glutamiltransferase/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Seguimentos , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Hospitalização/estatística & dados numéricos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Estudos Prospectivos , Sistema de Registros/estatística & dados numéricos , Medição de Risco/métodos , Volume Sistólico/fisiologia , Função Ventricular/fisiologia
18.
Turk Kardiyol Dern Ars ; 47(8): 638-645, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31802775

RESUMO

OBJECTIVE: There are various cardiovascular abnormalities in end-stage liver disease (ESLD). In these patients, left ventricular (LV) systolic function is normal at rest but deteriorates during stress. This deterioration may be due to subclinical myocardial dysfunction. This study evaluated global LV and right ventricular (RV) functions using 2-dimensional (2D) speckle tracking in patients with ESLD. METHODS: Forty liver transplant candidates with ESLD and 26 healthy individuals were included in the study. All of the patients underwent conventional echocardiographic measurement. Longitudinal, circumferential, and radial strain measurements, as well as apical and parasternal short-axis image recordings were obtained. All 2D strain measurements were measured with offline analysis using velocity vector imaging (VVI) software. RESULTS: In the apical 4- and 2-chamber measurements, the LV mean longitudinal strain was significantly lower in the patient group compared with that of the control group (-16.0±3.2% versus -17.6±2.2%, -16.7±3.3% versus -18.7 ±2.1 ± 2.1 %; p=0.002, respectively). The LV mean circumfe-rential strain did not differ between groups. The LV mean radial strain and RV longitudinal strain were significantly lower in the patient group (45.4±10.7 vs. 52.7±10.8%; p=0.01 and -19.2±3.5% versus -21.5±3.6%; p=0.03, respectively). CONCLUSION: Subclinical impairment of global LV and RV systolic functions was determined in liver transplantation candidates using VVI. This deterioration was detected in longitudinal and radial deformation rather than circumferential deformation mechanics, which is consistent with early-stage LV myocardial dysfunction.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Ecocardiografia/métodos , Transplante de Fígado , Transplantados , Adulto , Doenças Assintomáticas , Cardiomiopatias/fisiopatologia , Estudos de Coortes , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Função Ventricular/fisiologia
19.
Cardiovasc Ultrasound ; 17(1): 26, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722710

RESUMO

A high incidence of left ventricular diastolic dysfunction and increased risk of cardiovascular events have been reported in patients with diabetes mellitus. Sodium glucose cotransporter 2 (SGLT2) inhibitors selectively inhibit kidney glucose and sodium reabsorption, and cardiovascular benefits of SGLT2 inhibitors beyond other antidiabetic drugs have been reported in type 2 diabetes mellitus (T2DM) clinical trials. However, underlying mechanisms contributing to the improvement of cardiovascular outcomes have not been clearly identified. In this review, likely mechanisms of SGLT2 inhibitors contributing to a favorable cardiovascular outcomes are discussed based on experimental and clinical studies on cardiac function.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Função Ventricular/efeitos dos fármacos , Animais , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Saúde Global , Humanos , Incidência , Função Ventricular/fisiologia
20.
Am J Prev Med ; 57(6): e195-e202, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31753272

RESUMO

INTRODUCTION: This study used causal mediation analysis to assess the life-course associations of a favorable childhood psychosocial environment with left ventricular mass and diastolic function in adulthood and the extent to which adult health behaviors mediate these associations. METHODS: The sample included 880 participants (56% women) from the Young Finns Study with data on the childhood environment from 1980, adult health behaviors (smoking, physical activity, diet, and BMI) from 2001 and an echocardiographic assessment of the left ventricular mass (g/m2.7) and diastolic function (E/e' ratio; higher values indicating a lower diastolic function) from 2011. The associations of the childhood environment with the left ventricular mass and E/e' ratio and mediation pathways through health behaviors were assessed using marginal structural models that were controlled for age, sex, and time-dependent confounding by adult socioeconomic position (measured as educational attainment) via inverse probability weighting. The data were analyzed in 2018-2019. RESULTS: The mean age in 2011 was 41 (range 34-49) years. Those above versus below the median childhood score had a 1.28 g/m2.7 lower left ventricular mass (95% CI= -2.63, 0.07) and a 0.18 lower E/e' ratio (95% CI= -0.39, 0.03). There was no evidence for indirect effects from childhood environments to left ventricular outcomes through adult health behaviors after controlling for time-dependent confounding by the adult socioeconomic position (indirect effect ß= -0.30, 95% CI= -1.22, 0.63 for left ventricular mass; ß= -0.04, 95% CI= -0.18, 0.11 for E/e' ratio). The results after multiple imputation were similar. CONCLUSIONS: A favorable childhood environment is associated with more optimal cardiac structure and function in adulthood. After accounting for socioeconomic positions, adult health behaviors explain little of the associations.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Família/psicologia , Meio Social , Função Ventricular/fisiologia , Adolescente , Adulto , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/psicologia , Criança , Pré-Escolar , Ecocardiografia , Feminino , Finlândia , Comportamentos Relacionados com a Saúde , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores Socioeconômicos
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