Eric Ebenroth - Academia.edu (original) (raw)

Papers by Eric Ebenroth

BMC Cardiovascular Disorders

Background: Cardiac manifestations of neonatal lupus include an array of structural and conductio... more Background: Cardiac manifestations of neonatal lupus include an array of structural and conduction abnormalities due to placental transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies. Late-onset neonatal lupus cardiomyopathies, occurring outside the neonatal period, is an infrequently reported manifestation with unknown pathophysiology and poorly defined treatment regimens. Due to the rarity of this condition, additional studies and case reports are required to better understand and manage late-onset neonatal lupus cardiomyopathies. Case presentation: A 4-week-old female, born to a mother with known anti-SSA/Ro and anti-SSB/La autoantibodies, presents with classic cutaneous manifestations for neonatal lupus and is found to have left bundle branch block, severely dilated cardiomyopathy with an ejection fraction of 25%, and a thin echogenic dyskinetic ventricular septum. Weekly second trimester and 30-week fetal echocardiograms showed no signs of structural or conduction abnormalities. There were no histologic signs of inflammation on cardiac tissue biopsy. After a complicated hospital course, she was successfully treated with biventricular pacemaker, intravenous immunoglobulin, and plasmapheresis. Conclusions: We present a case of late-onset neonatal lupus with severe dilated cardiomyopathy, a dyskinetic ventricular septum, and left bundle branch block. To our knowledge, the dyskinetic ventricular septum has never been reported and left bundle branch block is rarely reported in NL. This case further validates the need for long term cardiac follow up for patients born with NL, even if lacking cardiac manifestations in the peripartum period. We characterize a unique presentation of a rare clinical entity, highlighting the diagnostic challenges, and describe a successful treatment course.

Journal of the American College of Cardiology

Cardiology in the Young

In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberran... more In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberrant left subclavian artery, and left ligamentum arteriosus in which there is atresia of the proximal left subclavian artery is described. Imaging modalities were non-diagnostic and the patient was sent to surgery based on strong clinical suspicion. Her anatomy was delineated in the operating room and the ring was successfully repaired.

International Journal of Clinical Medicine

A female at 28 weeks gestation was referred to pediatric cardiology for a fetal arrhythmia. The e... more A female at 28 weeks gestation was referred to pediatric cardiology for a fetal arrhythmia. The echocardiogram revealed premature constriction of the fetal ductus arteriosus. Her work up was unremarkable except for her use of an herbal supplement, grape seed extract, which is advertised as a potent anti-inflammatory medication, and has biochemical properties similar to other medications that have been shown to cause premature ductal constriction. The use of herbal remedies increases each year. Although the public is inundated with radio, television, and internet advertisements for these products, little unbiased information regarding the possible dangers of toxicity or adverse reactions exists. As physicians, we need to be aware of these products, and counsel our patients accordingly.

ABSTRACT Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the ol... more ABSTRACT Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atrial baffle (BAFFLE) or the now more commonly used arterial switch operation (SWITCH). Numerous studies have shown that post-operative DTGA patients, especially after the BAFFLE, have decreased exercise capacity which has been primarily attributed to cardiovascular limitations. Pulmonary limitations to peak aerobic capacity have been largely overlooked. This study focused on the impact of pulmonary limiting factors on peak exercise capacity in DTGA patients after each surgical repair. Methods: Resting pulmonary function was compared for BAFFLE(n=34) and SWITCH(n=32) patients and peak exercise variables were also compared. One pediatric pulmonologist analyzed flow volume loops for a restrictive lung disease marker, forced vital capacity(FVC), and the obstructive lung disease markers of forced expiratory volume in one second(FEV1.0) and forced mid-expiratory flow rates(FEF25-75%). Breathing reserve was calculated. Data was adjusted for size and age differences. Results: Lung disease (restrictive and/or obstructive) was present in 53% of patients post-DTGA repair (BAFFLE 62% and SWITCH 44%;p=0.14). ANOVA models of Pulmonary Variables BAFFLE(n=34) SWITCH(n=32) p-value Forced Vital Capacity(% of predicted value) 79.2 13.5 85.9 11.8 0.04* Forced Expiratory Volume 1.0(% of predicted value) 80.2 14.9 86.4 13.8 0.09 Forced Expiratory Flow 25-75%(% of predicted value) 89.2 28.0 85.3 26.2 0.26 ANOVA models of Exercise Variables BAFFLE(n=30) SWITCH(n=25) p-value Peak Minute Ventilation(VEmax)(% of predicted) 79.9 18.7 87.8 17.3 <0.01* Breathing Reserve(%) 27.3 28.3 13.0 19.2 0.04* Peak Oxygen Pulse(% of predicted) 82.7 20.5 94.7 19.3 0.04* Peak Aerobic Capacity(VO2peak)(ml/kg/min) 26.6 6.7 37.3 8.5 <0.01* * difference between BAFFLE and SWITCH is significant at p<0.05 Conclusion: Surprisingly, the majority of patients after surgical repair for DTGA have an underappreciated occurrence of lung disease, even after the near-anatomical correction of the SWITCH. SWITCH patients have a high frequency of resting pulmonary disease, a diminished breathing reserve, a normal oxygen pulse and a mildly diminished VO2peak compared to normals, suggesting a pulmonary limitation to peak aerobic capacity. BAFFLE patients have lower VO2peaks, higher breathing reserves and lower oxygen pulses than SWITCH patients, suggesting primarily a cardiac limitation to VO2peak with probable secondary pulmonary limitation. Both surgical repair groups for DTGA demonstrated significant lung disease and at least mildly diminished peak exercise tolerance. Clinicians caring for DTGA patients need to be aware of this for identification and treatment of lung disease to optimize functional clinical outcomes.

ABSTRACT Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or ... more ABSTRACT Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Outlet Right Ventricle(DORV) patients is a debated topic. It is logical that maximal aerobic capacity(VO2peak) would decline when a patient needs a conduit replacement, but a diminished VO2peak has not been consistently present in patients pre-RV-PA conduit replacement . Despite improved cardiac hemodynamics post-op, patients have no improvement in VO2peak. Patient 1-2 years post-ASD repair with sternotomies have diminished lung function limiting their VO2peak. Our hypotheses were: 1) that the impact of a secondary sternotomy included in the RV-PA conduit replacement may limit VO2peak up to two years post-op explaining lack of change in VO2peak post-op 2) that VO2peak is limited by non-cardiac factors pre- and/or post-op, explaining why improvement in cardiac function post-op would not change VO2peak. Methods: We prospectively evaluated resting echocardiograms, resting flow volume loops and maximal exercise treadmill test with gas exchange data on patients(n=26, median age 17.8 years) with TOF or DORV before and 6-24 months after their RV-PA conduit revision. Each flow volume loop was reviewed by a Pulmonologist and categorized as obstructive, restrictive, both obstructive and restrictive, or normal. Six pre-op flow volume loops and 4 post-op flow volume loops did not meet modified ATS criteria and were excluded. Each maximal exercise test was interpreted by an Exercise Physiologist using Eschenbacher’s algorithm to determine ones’ primary and secondary limiting factors to exercise. Results: There was no change in VO2peak(27.7 ±8.1 vs. 28.6 ± 8.5 ml/kg/min; p=0.522), forced vital capacity(p=0.66), forced expiratory volume one(p=0.64), FEV1/FVC ratio(p=0.50), forced expiratory flow 25-75%(p=0.33) or breathing reserve(p=0.40) after the conduit revision. Patients had a significant decrease in their RV dimensions post-op(Pre: 2.71 ± 0.95cm, Post: 2.22 ± 1.06cm; p=0.006). Flow Volume Loop Parameter Pre-op Post-op Obstructive 5% 13.6% Restricted 40% 45.5% Obstructive & Restricted 40% 23% Normal 15% 18% Primary Exercise Limitation Pre-Op Post-Op Cardiac 26.9% 34.6% Ventilatory 46.2% 46.2% Ventilatory & Circulatory Limitation 7.7% 7.7% Circulatory 0% 3.8% Normal in all Categories 3.8% 3.8% Incomplete Data 15.4% 3.8% Conclusions: TOF and DORV patients have high rates of abnormal lung function, but resting lung function does not change significantly after RV-PA conduit revision. There is no increase in frequency of pulmonary limitation to VO2peak post-op, but a significant percentage of TOF and DORV patients display persistent pulmonary limitations to VO2peak pre and post-op. Only 32% of patients pre-op had a primary cardiac limitation to VO2peak, despite right ventricular volume overload and significant pulmonary insufficiency pre-op. VO2peak remains unchanged in this population post-op, despite improved cardiac hemodynamics, if they are not cardiac limited prior to their RV-PA conduit revision. Utilization of a metabolic test interpretation algorithm will improve interpretation and clinical decision making.

Pediatric Cardiology, 2006

Journal of Applied Physiology, 2008

... Am J Respir Crit Care Med 161: 141–146, 2000.[Abstract/Free Full Text]; Laffey JG, Tanaka M, ... more ... Am J Respir Crit Care Med 161: 141–146, 2000.[Abstract/Free Full Text]; Laffey JG, Tanaka M, Engelberts D, Luo X, Yuan S, Transwell ... J Appl Physiol 70: 405–415, 1991.[Abstract/Free Full Text]; McCrory C, Ryan M, Doherty P. Falsely reassuring pulse oximetry in the presence of ...

Journal of Applied Physiology, 2008

Patients with single ventricle are often quite ill and present complex management dilemmas. The d... more Patients with single ventricle are often quite ill and present complex management dilemmas. The distribution of blood flow to the systemic and pulmonary circulations, which in this patient population are in parallel rather than series, depends primarily upon the relative resistances of the respective vascular beds. The entire cardiac output is managed by the single ventricle and must somehow divide itself between the systemic and pulmonary circuits. As pulmonary vascular resistance decreases after birth, many of these children will suffer from overcirculation into the pulmonary circuit. In patients with ductal dependent systemic circulation, such as hypoplastic left heart syndrome, this can result in a paucity of systemic circulation with concomitant acidosis (Figure 1A). Barnea developed a wonderful mathematical model of the univentricular circulation 1 and tested it through various manipulations of cardiac output, systemic arterial and venous oxygen saturations, pulmonary venous oxygen saturations, and Qp:Qs. He demonstrated that maximal oxygen delivery to the tissues would be obtained by Qp:Qs slightly less than 1 and that for higher Qp:Qs ratios, oxygen delivery to the tissues would actually decrease. He also

Congestive Heart Failure, 2004

Cardiac output (CO) is an important diagnostic and prognostic tool for patients with ventricular ... more Cardiac output (CO) is an important diagnostic and prognostic tool for patients with ventricular dysfunction. Pulmonary hypertension patients undergo invasive right heart catheterization to determine pulmonary vascular and cardiac hemodynamics. Thermodilution (TD) and direct Fick method are the most common methods of CO determination but are costly and may be associated with complications. The latest generation of impedance cardiography (ICG) provides noninvasive estimation of CO and is now validated. The purpose of this study was to compare ICG measurement of CO to TD and direct Fick in pulmonary hypertension patients. Thirty-nine enrolled patients were analyzed: 44% were male and average age was 50.8+/-17.4 years. Results for bias and precision of cardiac index were as follows: ICG vs. Fick (-0.13 L/min/m2 and 0.46 L/min/m2), TD vs. Fick (0.10 L/min/m2 and 0.41 L/min/m2), ICG vs. TD (respectively, with a 95% level of agreement between -0.72 and 0.92 L/min/m2; CO correlation of ICG vs. Fick, TD vs. Fick, and ICG vs. TD was 0.84, 0.89, and 0.80, respectively). ICG provides an accurate, useful, and cost-effective method for determining CO in pulmonary hypertension patients, and is a potential tool for following responses to therapeutic interventions.

Congenital Heart Disease, 2012

This study compares image quality, cost, right ventricular ejection fraction analysis, and baffle... more This study compares image quality, cost, right ventricular ejection fraction analysis, and baffle visualization between transthoracic echocardiography and cardiac magnetic resonance imaging in those status post atrial switch for transposition of the great arteries. Background. This population requires imaging for serial evaluations. Transthoracic echocardiography is often first line but has drawbacks, many of which are addressed by cardiac magnetic resonance imaging. Methods. Twelve patients (mean age 25 years) with relatively concurrent (mean 157 days) studies were included. Three separate echocardiography and magnetic resonance imaging physicians independently analyzed baffles, image quality, and right ventricular ejection fractions. Institutional and Medicaid charges were compared. Results. For right ventricular ejection fraction, echocardiography (36.1%) underestimated cardiac magnetic resonance imaging (47.8%, P = .002). Image quality for transthoracic echocardiography was significantly rated lower than cardiac magnetic resonance imaging (P = .002). Baffles were better seen in cardiac magnetic resonance imaging (transthoracic echocardiography vs. cardiac magnetic resonance imaging: superior vena cava 86% vs. 100% [P = .063]; inferior vena cava 33% vs. 97% [P = .002]; pulmonary vein 92% vs. 100% [P = .250]). Comparing hospital charges and Medicaid reimbursement, transthoracic echocardiography respectively costs 18% and 38% less than cardiac magnetic resonance imaging. Conclusions. In conclusion, transthoracic echocardiography underestimated right ventricular ejection fraction compared to cardiac magnetic resonance imaging. Cardiac magnetic resonance imaging had consistently higher image quality and better visualization of the baffles. Cost differences are minimal. We propose that cardiac magnetic resonance imaging be considered first line for imaging in certain patients' status post atrial switch procedure.

Pediat Res, 2005

ABSTRACT Cardiac masses in neonates are extremely rare and usually represent either tumors or thr... more ABSTRACT Cardiac masses in neonates are extremely rare and usually represent either tumors or thrombi. Management of cardiac tumors has been well described in this patient population, but a paucity of data exists on the management of cardiac thrombi, with the few reported cases focusing on outcomes following thrombolytic therapy (rt-PA, urokinase, or streptokinase). This study was undertaken to evaluate the outcome of cardiac thrombi in neonates who do not receive thrombolytic therapy.

Background: Infectious endocarditis (IE) is challenging to diagnose, and a source of significant ... more Background: Infectious endocarditis (IE) is challenging to diagnose, and a source of significant morbidity and mortality. The 2000 Duke criteria recommend the use of transesophageal over transthoracic echocardiography, when clinical suspicion is high. Unfortunately, the need for sedation in pediatric patients makes this difficult, requiring more resources and adding additional risks. However, transthoracic echocardiography is easily performed without sedation, and can achieve excellent image quality in children. Purpose: Compare the relative role of transthoracic echocardiography in the diagnosis of IE for children with and without CHD. Methods: The cardiology database was examined for all echocardiograms ordered for evaluation of endocarditis between 1/1999 and 1/2010. Keywords included: endocarditis, fever, vegetation, thrombus, positive culture, infection, bacteremia and sepsis. IE was diagnosed by echocardiography for the following: vegetations, abscess, thrombus, new valvular d...

Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atria... more Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atrial baffle (BAFFLE) or the now more commonly used arterial switch operation (SWITCH). Numerous studies have shown that post-operative DTGA patients, especially after the BAFFLE, have decreased exercise capacity which has been primarily attributed to cardiovascular limitations. Pulmonary limitations to peak aerobic capacity have been largely overlooked. This study focused on the impact of pulmonary limiting factors on peak exercise capacity in DTGA patients after each surgical repair. Methods: Resting pulmonary function was compared for BAFFLE(n=34) and SWITCH(n=32) patients and peak exercise variables were also compared. One pediatric pulmonologist analyzed flow volume loops for a restrictive lung disease marker, forced vital capacity(FVC), and the obstructive lung disease markers of forced expiratory volume in one second(FEV1.0) and forced mid-expiratory flow rates(FEF25-75%). Breathing r...

Purpose: The most common screening method for Long QT Syndrome (LQTS) and drug-induced QT prolong... more Purpose: The most common screening method for Long QT Syndrome (LQTS) and drug-induced QT prolongation is evaluation of the corrected QT (QTc) interval on electrocardiogram (ECG) with adjustment for heart rate made by Bazett’s formula. Several studies have shown this formula to overcorrect the QTc interval at faster heart rates, which can lead to unnecessary testing. The correct formula to use for correction of heart rate remains controversial. Previously, in a large pediatric population, we identified up to 8% and 44% of healthy children having a QTc value >450ms at rest and after hyperventilation when using Bazett’s formula. Our purpose was to investigate the differences of four different QT correction formulas at varying heart rates, in hopes of providing guidance to pediatricians in their evaluation for patients at risk for ventricular tachyarrythmias. Methods: A retrospective review was performed on 182 healthy pediatric patients who were referred for exercise stress testing...

Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Ou... more Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Outlet Right Ventricle(DORV) patients is a debated topic. It is logical that maximal aerobic capacity(VO2peak) would decline when a patient needs a conduit replacement, but a diminished VO2peak has not been consistently present in patients pre-RV-PA conduit replacement . Despite improved cardiac hemodynamics post-op, patients have no improvement in VO2peak. Patient 1-2 years post-ASD repair with sternotomies have diminished lung function limiting their VO2peak. Our hypotheses were: 1) that the impact of a secondary sternotomy included in the RV-PA conduit replacement may limit VO2peak up to two years post-op explaining lack of change in VO2peak post-op 2) that VO2peak is limited by non-cardiac factors pre- and/or post-op, explaining why improvement in cardiac function post-op would not change VO2peak. Methods: We prospectively evaluated resting echocardiograms, resting flow volume loops an...

Mitochondrion, 2010

Left ventricular noncompaction (LVNC) is a genetically heterogeneous condition and several nuclea... more Left ventricular noncompaction (LVNC) is a genetically heterogeneous condition and several nuclear loci have been associated with the defect. However, they only account for a small percentage of patients. Existing evidences suggest that pathogenic mitochondrial DNA (mtDNA) mutations and consequent mitochondrial malfunction can be an important component in the etiology of LVNC. To investigate if mtDNA mutation can serve as a primary cause for LVNC, complete nucleotide sequences of mitochondrial genomes from 20 LVNC patients were determined by Illumina parallel sequencing technology and analyzed by MitoMaster. Substitutions of a highly conserved Met31 in ND1 caused by rare mitochondrial single nucleotide polymorphisms (mtSNP) A3397G and T3398C were identified from two LVNC patients. Previously, T3398C has been reported from another LVNC patient, indicating mutations in Met31 in ND1 and resultant defects in complex I can be associated with LVNC. Additionally, three mtSNPs in protein-co...

Pediatric cardiology, 2014

Optimal timing of pulmonary valve replacement (PVR) for pulmonary regurgitation is a debated topi... more Optimal timing of pulmonary valve replacement (PVR) for pulmonary regurgitation is a debated topic. It is logical that maximal aerobic capacity (VO2peak) would decline when a PVR is needed, but a diminished VO2peak is not always present before PVR, and previous studies show no improvement in VO2peak after PVR. This study aimed to evaluate changes in resting spirometry from pre- to post-PVR sternotomy, to determine the limiting factors of VO2peak before and after PVR, and to determine whether changes in resting lung function after PVR may explain the lack of improvement in VO2peak after surgery. For 26 patients (age, 19.7 ± 7.8 years) with a history of right ventricular outflow tract revision, the study prospectively evaluated echocardiograms, resting spirometry, and maximal exercise tests before PVR and then an average of 15 months after PVR. Flow volume loops were reviewed by a pulmonologist and categorized as obstructive, restrictive, both obstructive and restrictive, or normal. E...

BMC Cardiovascular Disorders

Background: Cardiac manifestations of neonatal lupus include an array of structural and conductio... more Background: Cardiac manifestations of neonatal lupus include an array of structural and conduction abnormalities due to placental transference of maternal anti-SSA/Ro and anti-SSB/La autoantibodies. Late-onset neonatal lupus cardiomyopathies, occurring outside the neonatal period, is an infrequently reported manifestation with unknown pathophysiology and poorly defined treatment regimens. Due to the rarity of this condition, additional studies and case reports are required to better understand and manage late-onset neonatal lupus cardiomyopathies. Case presentation: A 4-week-old female, born to a mother with known anti-SSA/Ro and anti-SSB/La autoantibodies, presents with classic cutaneous manifestations for neonatal lupus and is found to have left bundle branch block, severely dilated cardiomyopathy with an ejection fraction of 25%, and a thin echogenic dyskinetic ventricular septum. Weekly second trimester and 30-week fetal echocardiograms showed no signs of structural or conduction abnormalities. There were no histologic signs of inflammation on cardiac tissue biopsy. After a complicated hospital course, she was successfully treated with biventricular pacemaker, intravenous immunoglobulin, and plasmapheresis. Conclusions: We present a case of late-onset neonatal lupus with severe dilated cardiomyopathy, a dyskinetic ventricular septum, and left bundle branch block. To our knowledge, the dyskinetic ventricular septum has never been reported and left bundle branch block is rarely reported in NL. This case further validates the need for long term cardiac follow up for patients born with NL, even if lacking cardiac manifestations in the peripartum period. We characterize a unique presentation of a rare clinical entity, highlighting the diagnostic challenges, and describe a successful treatment course.

Journal of the American College of Cardiology

Cardiology in the Young

In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberran... more In this report, a unique case of a symptomatic vascular ring formed by right aortic arch, aberrant left subclavian artery, and left ligamentum arteriosus in which there is atresia of the proximal left subclavian artery is described. Imaging modalities were non-diagnostic and the patient was sent to surgery based on strong clinical suspicion. Her anatomy was delineated in the operating room and the ring was successfully repaired.

International Journal of Clinical Medicine

A female at 28 weeks gestation was referred to pediatric cardiology for a fetal arrhythmia. The e... more A female at 28 weeks gestation was referred to pediatric cardiology for a fetal arrhythmia. The echocardiogram revealed premature constriction of the fetal ductus arteriosus. Her work up was unremarkable except for her use of an herbal supplement, grape seed extract, which is advertised as a potent anti-inflammatory medication, and has biochemical properties similar to other medications that have been shown to cause premature ductal constriction. The use of herbal remedies increases each year. Although the public is inundated with radio, television, and internet advertisements for these products, little unbiased information regarding the possible dangers of toxicity or adverse reactions exists. As physicians, we need to be aware of these products, and counsel our patients accordingly.

ABSTRACT Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the ol... more ABSTRACT Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atrial baffle (BAFFLE) or the now more commonly used arterial switch operation (SWITCH). Numerous studies have shown that post-operative DTGA patients, especially after the BAFFLE, have decreased exercise capacity which has been primarily attributed to cardiovascular limitations. Pulmonary limitations to peak aerobic capacity have been largely overlooked. This study focused on the impact of pulmonary limiting factors on peak exercise capacity in DTGA patients after each surgical repair. Methods: Resting pulmonary function was compared for BAFFLE(n=34) and SWITCH(n=32) patients and peak exercise variables were also compared. One pediatric pulmonologist analyzed flow volume loops for a restrictive lung disease marker, forced vital capacity(FVC), and the obstructive lung disease markers of forced expiratory volume in one second(FEV1.0) and forced mid-expiratory flow rates(FEF25-75%). Breathing reserve was calculated. Data was adjusted for size and age differences. Results: Lung disease (restrictive and/or obstructive) was present in 53% of patients post-DTGA repair (BAFFLE 62% and SWITCH 44%;p=0.14). ANOVA models of Pulmonary Variables BAFFLE(n=34) SWITCH(n=32) p-value Forced Vital Capacity(% of predicted value) 79.2 13.5 85.9 11.8 0.04* Forced Expiratory Volume 1.0(% of predicted value) 80.2 14.9 86.4 13.8 0.09 Forced Expiratory Flow 25-75%(% of predicted value) 89.2 28.0 85.3 26.2 0.26 ANOVA models of Exercise Variables BAFFLE(n=30) SWITCH(n=25) p-value Peak Minute Ventilation(VEmax)(% of predicted) 79.9 18.7 87.8 17.3 <0.01* Breathing Reserve(%) 27.3 28.3 13.0 19.2 0.04* Peak Oxygen Pulse(% of predicted) 82.7 20.5 94.7 19.3 0.04* Peak Aerobic Capacity(VO2peak)(ml/kg/min) 26.6 6.7 37.3 8.5 <0.01* * difference between BAFFLE and SWITCH is significant at p<0.05 Conclusion: Surprisingly, the majority of patients after surgical repair for DTGA have an underappreciated occurrence of lung disease, even after the near-anatomical correction of the SWITCH. SWITCH patients have a high frequency of resting pulmonary disease, a diminished breathing reserve, a normal oxygen pulse and a mildly diminished VO2peak compared to normals, suggesting a pulmonary limitation to peak aerobic capacity. BAFFLE patients have lower VO2peaks, higher breathing reserves and lower oxygen pulses than SWITCH patients, suggesting primarily a cardiac limitation to VO2peak with probable secondary pulmonary limitation. Both surgical repair groups for DTGA demonstrated significant lung disease and at least mildly diminished peak exercise tolerance. Clinicians caring for DTGA patients need to be aware of this for identification and treatment of lung disease to optimize functional clinical outcomes.

ABSTRACT Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or ... more ABSTRACT Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Outlet Right Ventricle(DORV) patients is a debated topic. It is logical that maximal aerobic capacity(VO2peak) would decline when a patient needs a conduit replacement, but a diminished VO2peak has not been consistently present in patients pre-RV-PA conduit replacement . Despite improved cardiac hemodynamics post-op, patients have no improvement in VO2peak. Patient 1-2 years post-ASD repair with sternotomies have diminished lung function limiting their VO2peak. Our hypotheses were: 1) that the impact of a secondary sternotomy included in the RV-PA conduit replacement may limit VO2peak up to two years post-op explaining lack of change in VO2peak post-op 2) that VO2peak is limited by non-cardiac factors pre- and/or post-op, explaining why improvement in cardiac function post-op would not change VO2peak. Methods: We prospectively evaluated resting echocardiograms, resting flow volume loops and maximal exercise treadmill test with gas exchange data on patients(n=26, median age 17.8 years) with TOF or DORV before and 6-24 months after their RV-PA conduit revision. Each flow volume loop was reviewed by a Pulmonologist and categorized as obstructive, restrictive, both obstructive and restrictive, or normal. Six pre-op flow volume loops and 4 post-op flow volume loops did not meet modified ATS criteria and were excluded. Each maximal exercise test was interpreted by an Exercise Physiologist using Eschenbacher’s algorithm to determine ones’ primary and secondary limiting factors to exercise. Results: There was no change in VO2peak(27.7 ±8.1 vs. 28.6 ± 8.5 ml/kg/min; p=0.522), forced vital capacity(p=0.66), forced expiratory volume one(p=0.64), FEV1/FVC ratio(p=0.50), forced expiratory flow 25-75%(p=0.33) or breathing reserve(p=0.40) after the conduit revision. Patients had a significant decrease in their RV dimensions post-op(Pre: 2.71 ± 0.95cm, Post: 2.22 ± 1.06cm; p=0.006). Flow Volume Loop Parameter Pre-op Post-op Obstructive 5% 13.6% Restricted 40% 45.5% Obstructive & Restricted 40% 23% Normal 15% 18% Primary Exercise Limitation Pre-Op Post-Op Cardiac 26.9% 34.6% Ventilatory 46.2% 46.2% Ventilatory & Circulatory Limitation 7.7% 7.7% Circulatory 0% 3.8% Normal in all Categories 3.8% 3.8% Incomplete Data 15.4% 3.8% Conclusions: TOF and DORV patients have high rates of abnormal lung function, but resting lung function does not change significantly after RV-PA conduit revision. There is no increase in frequency of pulmonary limitation to VO2peak post-op, but a significant percentage of TOF and DORV patients display persistent pulmonary limitations to VO2peak pre and post-op. Only 32% of patients pre-op had a primary cardiac limitation to VO2peak, despite right ventricular volume overload and significant pulmonary insufficiency pre-op. VO2peak remains unchanged in this population post-op, despite improved cardiac hemodynamics, if they are not cardiac limited prior to their RV-PA conduit revision. Utilization of a metabolic test interpretation algorithm will improve interpretation and clinical decision making.

Pediatric Cardiology, 2006

Journal of Applied Physiology, 2008

... Am J Respir Crit Care Med 161: 141–146, 2000.[Abstract/Free Full Text]; Laffey JG, Tanaka M, ... more ... Am J Respir Crit Care Med 161: 141–146, 2000.[Abstract/Free Full Text]; Laffey JG, Tanaka M, Engelberts D, Luo X, Yuan S, Transwell ... J Appl Physiol 70: 405–415, 1991.[Abstract/Free Full Text]; McCrory C, Ryan M, Doherty P. Falsely reassuring pulse oximetry in the presence of ...

Journal of Applied Physiology, 2008

Patients with single ventricle are often quite ill and present complex management dilemmas. The d... more Patients with single ventricle are often quite ill and present complex management dilemmas. The distribution of blood flow to the systemic and pulmonary circulations, which in this patient population are in parallel rather than series, depends primarily upon the relative resistances of the respective vascular beds. The entire cardiac output is managed by the single ventricle and must somehow divide itself between the systemic and pulmonary circuits. As pulmonary vascular resistance decreases after birth, many of these children will suffer from overcirculation into the pulmonary circuit. In patients with ductal dependent systemic circulation, such as hypoplastic left heart syndrome, this can result in a paucity of systemic circulation with concomitant acidosis (Figure 1A). Barnea developed a wonderful mathematical model of the univentricular circulation 1 and tested it through various manipulations of cardiac output, systemic arterial and venous oxygen saturations, pulmonary venous oxygen saturations, and Qp:Qs. He demonstrated that maximal oxygen delivery to the tissues would be obtained by Qp:Qs slightly less than 1 and that for higher Qp:Qs ratios, oxygen delivery to the tissues would actually decrease. He also

Congestive Heart Failure, 2004

Cardiac output (CO) is an important diagnostic and prognostic tool for patients with ventricular ... more Cardiac output (CO) is an important diagnostic and prognostic tool for patients with ventricular dysfunction. Pulmonary hypertension patients undergo invasive right heart catheterization to determine pulmonary vascular and cardiac hemodynamics. Thermodilution (TD) and direct Fick method are the most common methods of CO determination but are costly and may be associated with complications. The latest generation of impedance cardiography (ICG) provides noninvasive estimation of CO and is now validated. The purpose of this study was to compare ICG measurement of CO to TD and direct Fick in pulmonary hypertension patients. Thirty-nine enrolled patients were analyzed: 44% were male and average age was 50.8+/-17.4 years. Results for bias and precision of cardiac index were as follows: ICG vs. Fick (-0.13 L/min/m2 and 0.46 L/min/m2), TD vs. Fick (0.10 L/min/m2 and 0.41 L/min/m2), ICG vs. TD (respectively, with a 95% level of agreement between -0.72 and 0.92 L/min/m2; CO correlation of ICG vs. Fick, TD vs. Fick, and ICG vs. TD was 0.84, 0.89, and 0.80, respectively). ICG provides an accurate, useful, and cost-effective method for determining CO in pulmonary hypertension patients, and is a potential tool for following responses to therapeutic interventions.

Congenital Heart Disease, 2012

This study compares image quality, cost, right ventricular ejection fraction analysis, and baffle... more This study compares image quality, cost, right ventricular ejection fraction analysis, and baffle visualization between transthoracic echocardiography and cardiac magnetic resonance imaging in those status post atrial switch for transposition of the great arteries. Background. This population requires imaging for serial evaluations. Transthoracic echocardiography is often first line but has drawbacks, many of which are addressed by cardiac magnetic resonance imaging. Methods. Twelve patients (mean age 25 years) with relatively concurrent (mean 157 days) studies were included. Three separate echocardiography and magnetic resonance imaging physicians independently analyzed baffles, image quality, and right ventricular ejection fractions. Institutional and Medicaid charges were compared. Results. For right ventricular ejection fraction, echocardiography (36.1%) underestimated cardiac magnetic resonance imaging (47.8%, P = .002). Image quality for transthoracic echocardiography was significantly rated lower than cardiac magnetic resonance imaging (P = .002). Baffles were better seen in cardiac magnetic resonance imaging (transthoracic echocardiography vs. cardiac magnetic resonance imaging: superior vena cava 86% vs. 100% [P = .063]; inferior vena cava 33% vs. 97% [P = .002]; pulmonary vein 92% vs. 100% [P = .250]). Comparing hospital charges and Medicaid reimbursement, transthoracic echocardiography respectively costs 18% and 38% less than cardiac magnetic resonance imaging. Conclusions. In conclusion, transthoracic echocardiography underestimated right ventricular ejection fraction compared to cardiac magnetic resonance imaging. Cardiac magnetic resonance imaging had consistently higher image quality and better visualization of the baffles. Cost differences are minimal. We propose that cardiac magnetic resonance imaging be considered first line for imaging in certain patients' status post atrial switch procedure.

Pediat Res, 2005

ABSTRACT Cardiac masses in neonates are extremely rare and usually represent either tumors or thr... more ABSTRACT Cardiac masses in neonates are extremely rare and usually represent either tumors or thrombi. Management of cardiac tumors has been well described in this patient population, but a paucity of data exists on the management of cardiac thrombi, with the few reported cases focusing on outcomes following thrombolytic therapy (rt-PA, urokinase, or streptokinase). This study was undertaken to evaluate the outcome of cardiac thrombi in neonates who do not receive thrombolytic therapy.

Background: Infectious endocarditis (IE) is challenging to diagnose, and a source of significant ... more Background: Infectious endocarditis (IE) is challenging to diagnose, and a source of significant morbidity and mortality. The 2000 Duke criteria recommend the use of transesophageal over transthoracic echocardiography, when clinical suspicion is high. Unfortunately, the need for sedation in pediatric patients makes this difficult, requiring more resources and adding additional risks. However, transthoracic echocardiography is easily performed without sedation, and can achieve excellent image quality in children. Purpose: Compare the relative role of transthoracic echocardiography in the diagnosis of IE for children with and without CHD. Methods: The cardiology database was examined for all echocardiograms ordered for evaluation of endocarditis between 1/1999 and 1/2010. Keywords included: endocarditis, fever, vegetation, thrombus, positive culture, infection, bacteremia and sepsis. IE was diagnosed by echocardiography for the following: vegetations, abscess, thrombus, new valvular d...

Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atria... more Purpose: Surgical repairs for D-transposition of the great vessels (DTGA) include the older atrial baffle (BAFFLE) or the now more commonly used arterial switch operation (SWITCH). Numerous studies have shown that post-operative DTGA patients, especially after the BAFFLE, have decreased exercise capacity which has been primarily attributed to cardiovascular limitations. Pulmonary limitations to peak aerobic capacity have been largely overlooked. This study focused on the impact of pulmonary limiting factors on peak exercise capacity in DTGA patients after each surgical repair. Methods: Resting pulmonary function was compared for BAFFLE(n=34) and SWITCH(n=32) patients and peak exercise variables were also compared. One pediatric pulmonologist analyzed flow volume loops for a restrictive lung disease marker, forced vital capacity(FVC), and the obstructive lung disease markers of forced expiratory volume in one second(FEV1.0) and forced mid-expiratory flow rates(FEF25-75%). Breathing r...

Purpose: The most common screening method for Long QT Syndrome (LQTS) and drug-induced QT prolong... more Purpose: The most common screening method for Long QT Syndrome (LQTS) and drug-induced QT prolongation is evaluation of the corrected QT (QTc) interval on electrocardiogram (ECG) with adjustment for heart rate made by Bazett’s formula. Several studies have shown this formula to overcorrect the QTc interval at faster heart rates, which can lead to unnecessary testing. The correct formula to use for correction of heart rate remains controversial. Previously, in a large pediatric population, we identified up to 8% and 44% of healthy children having a QTc value >450ms at rest and after hyperventilation when using Bazett’s formula. Our purpose was to investigate the differences of four different QT correction formulas at varying heart rates, in hopes of providing guidance to pediatricians in their evaluation for patients at risk for ventricular tachyarrythmias. Methods: A retrospective review was performed on 182 healthy pediatric patients who were referred for exercise stress testing...

Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Ou... more Purpose: Optimal timing of the RV-PA conduit replacement in Tetralogy of Fallot(TOF) or Double Outlet Right Ventricle(DORV) patients is a debated topic. It is logical that maximal aerobic capacity(VO2peak) would decline when a patient needs a conduit replacement, but a diminished VO2peak has not been consistently present in patients pre-RV-PA conduit replacement . Despite improved cardiac hemodynamics post-op, patients have no improvement in VO2peak. Patient 1-2 years post-ASD repair with sternotomies have diminished lung function limiting their VO2peak. Our hypotheses were: 1) that the impact of a secondary sternotomy included in the RV-PA conduit replacement may limit VO2peak up to two years post-op explaining lack of change in VO2peak post-op 2) that VO2peak is limited by non-cardiac factors pre- and/or post-op, explaining why improvement in cardiac function post-op would not change VO2peak. Methods: We prospectively evaluated resting echocardiograms, resting flow volume loops an...

Mitochondrion, 2010

Left ventricular noncompaction (LVNC) is a genetically heterogeneous condition and several nuclea... more Left ventricular noncompaction (LVNC) is a genetically heterogeneous condition and several nuclear loci have been associated with the defect. However, they only account for a small percentage of patients. Existing evidences suggest that pathogenic mitochondrial DNA (mtDNA) mutations and consequent mitochondrial malfunction can be an important component in the etiology of LVNC. To investigate if mtDNA mutation can serve as a primary cause for LVNC, complete nucleotide sequences of mitochondrial genomes from 20 LVNC patients were determined by Illumina parallel sequencing technology and analyzed by MitoMaster. Substitutions of a highly conserved Met31 in ND1 caused by rare mitochondrial single nucleotide polymorphisms (mtSNP) A3397G and T3398C were identified from two LVNC patients. Previously, T3398C has been reported from another LVNC patient, indicating mutations in Met31 in ND1 and resultant defects in complex I can be associated with LVNC. Additionally, three mtSNPs in protein-co...

Pediatric cardiology, 2014

Optimal timing of pulmonary valve replacement (PVR) for pulmonary regurgitation is a debated topi... more Optimal timing of pulmonary valve replacement (PVR) for pulmonary regurgitation is a debated topic. It is logical that maximal aerobic capacity (VO2peak) would decline when a PVR is needed, but a diminished VO2peak is not always present before PVR, and previous studies show no improvement in VO2peak after PVR. This study aimed to evaluate changes in resting spirometry from pre- to post-PVR sternotomy, to determine the limiting factors of VO2peak before and after PVR, and to determine whether changes in resting lung function after PVR may explain the lack of improvement in VO2peak after surgery. For 26 patients (age, 19.7 ± 7.8 years) with a history of right ventricular outflow tract revision, the study prospectively evaluated echocardiograms, resting spirometry, and maximal exercise tests before PVR and then an average of 15 months after PVR. Flow volume loops were reviewed by a pulmonologist and categorized as obstructive, restrictive, both obstructive and restrictive, or normal. E...