Suellen Yin - Academia.edu (original) (raw)

Papers by Suellen Yin

Research paper thumbnail of Reference values of aerobic fitness in the contemporary paediatric population

European Journal of Preventive Cardiology

AimsThere has been a growing interest in the use of markers of aerobic physical fitness (VO2max a... more AimsThere has been a growing interest in the use of markers of aerobic physical fitness (VO2max assessed by cardiopulmonary exercise test (CPET)) in the follow-up of paediatric chronic diseases. The dissemination of CPET in paediatrics requires valid paediatric VO2max reference values to define the upper and lower normal limits. This study aimed to establish VO2max reference Z-score values, from a large cohort of children representative of the contemporary paediatric population, including those with extreme weights.Methods and resultsIn this cross-sectional study, 909 children aged 5 to 18 years old from the general French population (development cohort) and 232 children from the general German and US populations (validation cohort) underwent a CPET, following the guidelines on high-quality CPET assessment. Linear, quadratic, and polynomial mathematical regression equations were applied to identify the best VO2max Z-score model. Predicted and observed VO2max values using the VO2max ...

Research paper thumbnail of Abstract 15416: Longitudinal Assessment of Electrical-Mechanical Interactions in Children and Young Adults With Repaired Tetralogy of Fallot

Circulation, 2020

Introduction: Electrical-mechanical interactions contribute to arrhythmias, sudden cardiac death,... more Introduction: Electrical-mechanical interactions contribute to arrhythmias, sudden cardiac death, and right ventricular remodeling in repaired tetralogy of Fallot (TOF). Hypothesis: There are significant changes in electrocardiographic properties and electrical-mechanical interactions that occur over time after complete TOF repair and with pulmonary valve replacement (PVR). Methods: This retrospective cohort study of 177 patients, initially recruited for a cross-sectional research protocol, underwent complete TOF repair at 0.3±0.9 years with 21.5±4.2 years of clinical follow-up. We assessed ECG, Holter, cardiopulmonary exercise testing (CPET), and MRI data. We used linear mixed effects models to examine QRS duration (QRSd) and its rate of change over time, associations between comparable ECG and MRI, Holter and MRI, ECG and Holter, ECG and CPET, and pre-PVR and post-PVR results. Results: QRSd increased after TOF repair, but the rate of change decreased from 5.2 ms/year 1 year post-o...

Research paper thumbnail of A robust Fourier-based method to measure pulse pressure variability

Biomedical Signal Processing and Control, 2020

Objective-To propose a new method to estimate pulse pressure variability (PPV) in the arterial bl... more Objective-To propose a new method to estimate pulse pressure variability (PPV) in the arterial blood pressure waveform. Methods-Traditional techniques of calculating PPV using peak finding have a fundamental flaw that prevents them from accurately resolving PPV for small tidal volumes, limiting the use of PPV to only mechanical ventilated patients. The improved method described here addresses this limitation using Fourier analysis of an oscillatory signal that exhibits a time-varying modulation of its amplitude. The analysis reveals a constraint on the spectral representation that must be satisfied for any oscillatory signal that exhibits a time-varying modulation of its amplitude. This intrinsic mathematical structure is taken advantage of in order to improve the robustness of the algorithm. Results-The applicability of the method is tested using synthetic data and 100 h of physiologic data collected from patients admitted to Texas Children's Hospital. Significance and conclusion-The proposed method accurately recovers values of PPV at signal-to-noise ratios six times smaller than the traditional method. This is a significant advance for the potential use of PPV to recognize fluid responsiveness during low tidal volume ventilation or spontaneous breathing for which the signal-to-noise ratio is expected to be small.

Research paper thumbnail of Elevated Pulmonary Artery Pressure, Not Pulmonary Vascular Resistance, is an Independent Predictor of Morbidity Following Bidirectional Cavopulmonary Connection

Journal of the American College of Cardiology, 2016

Background: Successful single ventricle palliation relies on the pulmonary vasculature accommodat... more Background: Successful single ventricle palliation relies on the pulmonary vasculature accommodating non-pulsatile venous return from the body. Mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance (PVR) are two interdependent measures of pulmonary vasculature that can impact pulmonary blood flow following bidirectional cavopulmonary connection (BCPC). We sought to determine which of these two measures is a better predictor of outcomes following BCPC. Methods: A retrospective chart review was performed on patients (pts) who underwent BCPC at our institution between 2008 and 2014 for whom MPAP and PVR data were available. Baseline demographic data, preoperative hemodynamics, operative details and postoperative clinical variables were analyzed. MPAP was dichotomized at 15mmHG and indexed PVR at 3 Wood units (wu). Major morbidity was defined as need for extracorporeal membrane oxygenation, BCPC takedown, percutaneous intervention during BCPC admission, hospital length of stay greater than 1 standard deviation from the mean, or need for supplemental oxygen at discharge. Results are displayed as mean ± standard error of the mean. Results: 250 patients (136 males, 54%) were included in the analysis. Mean age at BCPC was 8.3 months (±0.34) and mean weight 6.9 kg (±0.12). 91 pts (36%) had elevated MPAP ≥15mmHg (17.4±0.27 vs 11.3±0.16). 21 pts (8.4%) had PVR >3wu (3.9±0.18 vs 1.8±.04). There were 9 (3.6%) deaths, and 49 patients (20%) sustained major morbidity. Elevated MPAP was associated with increased intubation days (5.4±1.5 vs 1.8±0.31), increased intensive care stay (10.1±1.8 vs 6.0±0.70), and increased need for sildenafil at discharge (28.5% vs 19.5%) (p<0.05). Conversely, elevated PVR was not associated with any of the variables studied. On multiple regression analysis, elevated MPAP was an independent predictor of major morbidity (p<0.05). Ventricular end diastolic pressure and need for preoperative oxygen supplementation were the only two independent predictors of mortality. Conclusions: Elevated MPAP, not PVR, is an independent predictor of morbidity following BCPC.

Research paper thumbnail of Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

American Journal of Respiratory Cell and Molecular Biology, 2010

With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacteri... more With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P , 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

Research paper thumbnail of Early presentation with late-onset Pompe disease genotype due to a genetic modifier: Lessons from newborn screening

Molecular Genetics and Metabolism, 2022

Research paper thumbnail of Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

American Journal of Respiratory Cell and Molecular Biology, 2010

With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacteri... more With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P , 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

Research paper thumbnail of Reference values of aerobic fitness in the contemporary paediatric population

European Journal of Preventive Cardiology

AimsThere has been a growing interest in the use of markers of aerobic physical fitness (VO2max a... more AimsThere has been a growing interest in the use of markers of aerobic physical fitness (VO2max assessed by cardiopulmonary exercise test (CPET)) in the follow-up of paediatric chronic diseases. The dissemination of CPET in paediatrics requires valid paediatric VO2max reference values to define the upper and lower normal limits. This study aimed to establish VO2max reference Z-score values, from a large cohort of children representative of the contemporary paediatric population, including those with extreme weights.Methods and resultsIn this cross-sectional study, 909 children aged 5 to 18 years old from the general French population (development cohort) and 232 children from the general German and US populations (validation cohort) underwent a CPET, following the guidelines on high-quality CPET assessment. Linear, quadratic, and polynomial mathematical regression equations were applied to identify the best VO2max Z-score model. Predicted and observed VO2max values using the VO2max ...

Research paper thumbnail of Abstract 15416: Longitudinal Assessment of Electrical-Mechanical Interactions in Children and Young Adults With Repaired Tetralogy of Fallot

Circulation, 2020

Introduction: Electrical-mechanical interactions contribute to arrhythmias, sudden cardiac death,... more Introduction: Electrical-mechanical interactions contribute to arrhythmias, sudden cardiac death, and right ventricular remodeling in repaired tetralogy of Fallot (TOF). Hypothesis: There are significant changes in electrocardiographic properties and electrical-mechanical interactions that occur over time after complete TOF repair and with pulmonary valve replacement (PVR). Methods: This retrospective cohort study of 177 patients, initially recruited for a cross-sectional research protocol, underwent complete TOF repair at 0.3±0.9 years with 21.5±4.2 years of clinical follow-up. We assessed ECG, Holter, cardiopulmonary exercise testing (CPET), and MRI data. We used linear mixed effects models to examine QRS duration (QRSd) and its rate of change over time, associations between comparable ECG and MRI, Holter and MRI, ECG and Holter, ECG and CPET, and pre-PVR and post-PVR results. Results: QRSd increased after TOF repair, but the rate of change decreased from 5.2 ms/year 1 year post-o...

Research paper thumbnail of A robust Fourier-based method to measure pulse pressure variability

Biomedical Signal Processing and Control, 2020

Objective-To propose a new method to estimate pulse pressure variability (PPV) in the arterial bl... more Objective-To propose a new method to estimate pulse pressure variability (PPV) in the arterial blood pressure waveform. Methods-Traditional techniques of calculating PPV using peak finding have a fundamental flaw that prevents them from accurately resolving PPV for small tidal volumes, limiting the use of PPV to only mechanical ventilated patients. The improved method described here addresses this limitation using Fourier analysis of an oscillatory signal that exhibits a time-varying modulation of its amplitude. The analysis reveals a constraint on the spectral representation that must be satisfied for any oscillatory signal that exhibits a time-varying modulation of its amplitude. This intrinsic mathematical structure is taken advantage of in order to improve the robustness of the algorithm. Results-The applicability of the method is tested using synthetic data and 100 h of physiologic data collected from patients admitted to Texas Children's Hospital. Significance and conclusion-The proposed method accurately recovers values of PPV at signal-to-noise ratios six times smaller than the traditional method. This is a significant advance for the potential use of PPV to recognize fluid responsiveness during low tidal volume ventilation or spontaneous breathing for which the signal-to-noise ratio is expected to be small.

Research paper thumbnail of Elevated Pulmonary Artery Pressure, Not Pulmonary Vascular Resistance, is an Independent Predictor of Morbidity Following Bidirectional Cavopulmonary Connection

Journal of the American College of Cardiology, 2016

Background: Successful single ventricle palliation relies on the pulmonary vasculature accommodat... more Background: Successful single ventricle palliation relies on the pulmonary vasculature accommodating non-pulsatile venous return from the body. Mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance (PVR) are two interdependent measures of pulmonary vasculature that can impact pulmonary blood flow following bidirectional cavopulmonary connection (BCPC). We sought to determine which of these two measures is a better predictor of outcomes following BCPC. Methods: A retrospective chart review was performed on patients (pts) who underwent BCPC at our institution between 2008 and 2014 for whom MPAP and PVR data were available. Baseline demographic data, preoperative hemodynamics, operative details and postoperative clinical variables were analyzed. MPAP was dichotomized at 15mmHG and indexed PVR at 3 Wood units (wu). Major morbidity was defined as need for extracorporeal membrane oxygenation, BCPC takedown, percutaneous intervention during BCPC admission, hospital length of stay greater than 1 standard deviation from the mean, or need for supplemental oxygen at discharge. Results are displayed as mean ± standard error of the mean. Results: 250 patients (136 males, 54%) were included in the analysis. Mean age at BCPC was 8.3 months (±0.34) and mean weight 6.9 kg (±0.12). 91 pts (36%) had elevated MPAP ≥15mmHg (17.4±0.27 vs 11.3±0.16). 21 pts (8.4%) had PVR >3wu (3.9±0.18 vs 1.8±.04). There were 9 (3.6%) deaths, and 49 patients (20%) sustained major morbidity. Elevated MPAP was associated with increased intubation days (5.4±1.5 vs 1.8±0.31), increased intensive care stay (10.1±1.8 vs 6.0±0.70), and increased need for sildenafil at discharge (28.5% vs 19.5%) (p<0.05). Conversely, elevated PVR was not associated with any of the variables studied. On multiple regression analysis, elevated MPAP was an independent predictor of major morbidity (p<0.05). Ventricular end diastolic pressure and need for preoperative oxygen supplementation were the only two independent predictors of mortality. Conclusions: Elevated MPAP, not PVR, is an independent predictor of morbidity following BCPC.

Research paper thumbnail of Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

American Journal of Respiratory Cell and Molecular Biology, 2010

With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacteri... more With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P , 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

Research paper thumbnail of Early presentation with late-onset Pompe disease genotype due to a genetic modifier: Lessons from newborn screening

Molecular Genetics and Metabolism, 2022

Research paper thumbnail of Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

American Journal of Respiratory Cell and Molecular Biology, 2010

With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacteri... more With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P , 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.