Main pulmonary artery (MPA) dilation is reported to occur in association with pulmonary valve (PV... more Main pulmonary artery (MPA) dilation is reported to occur in association with pulmonary valve (PV) abnormalities and in genetic diseases of connective tissue. To determine whether MPA dilation occurs with bicuspid aortic valve (BAV) in the absence of PV abnormality. MPA and aortic dimensions were investigated in 194 subjects with BAV and 178 controls matched for age, sex and body surface area (BSA) using transthoracic two-dimensional echocardiography. Using control measurements, linear regression of each parameter versus age, gender, and BSA(2/3) provided expected values. For each subject with BAV, the percentage divergence from expected value ((observed--expected value)/expected value) for each dimension was analysed. MPA and aortic measurements showed normal distribution in all subjects. PV annulus and MPA were larger in BAV; 17.7% positive divergence of MPA dimension from expected was found in diastole, and 16.7% in systole. Aortic dimensions at all levels measured were larger in BAV; divergence was greater distally than proximally (10% divergence at annulus, 31% at ascending aorta). In BAV, divergence of ascending aortic dimensions from expected values increased with age (r(2)=0.142, p=0.02), but MPA divergence from expected values did not increase with age (r(2)=0.001, p=0.296). MPA dilation occurs in association with BAV in the absence of PV abnormality, suggesting primary vessel wall pathology predisposing to arterial dilation. A systemic abnormality of connective tissue common to both arteries may be responsible, or the dilation may result from a common developmental exposure as both originate from the embryologic cono-truncus.
Journal of Thoracic and Cardiovascular Surgery, 2006
Objective: Robotic systems allow surgeons to perform minimally invasive cardiac surgery in adults... more Objective: Robotic systems allow surgeons to perform minimally invasive cardiac surgery in adults. Experience in the pediatric population, however, is limited. Perventricular closure of muscular ventricular septal defects has been reported in humans but requires a median sternotomy. The objective of this study was to assess the feasibility of robotically assisted closure of perimembranous ventricular septal defects by using the perventricular approach.
The Journal of thoracic and cardiovascular surgery, Jan 28, 2015
We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan o... more We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan operation. We aimed to measure hepatic stiffness using ultrasound and shear wave elastography (SWE) in a bidirectional cavopulmonary connection (BCPC) cohort. Subjects were prospectively recruited for real-time, hepatic, ultrasound-SWE for hepatic stiffness (kPa) and echocardiography. Doppler velocities, a velocity-time integral, flow volume, and resistive index, pulsatility index, and acceleration index were measured in celiac and superior mesenteric arteries, and in the main portal vein (MPV). Comparisons were made among subjects who had BCPC, subjects who were healthy, and a cohort of patients who had undergone the Fontan procedure. Forty subjects (20 patients who had BCPC; 20 age- and gender-matched control subjects) were studied. The hepatic stiffness in BCPC was elevated, compared with that in control subjects (7.2 vs 5.7 kPa; P = .039). Patients who had BCPC had significantly highe...
Left atrial (LA) function is an important modulator of left ventricular filling and has a prognos... more Left atrial (LA) function is an important modulator of left ventricular filling and has a prognostic role in adult heart failure, but pediatric data are limited. The aim of this study was to characterize the normal LA and right atrial (RA) strain (ε) and strain rate (SR) in infants and children. Atrial ε and SR were prospectively investigated in 153 subjects using two-dimensional speckle-tracking echocardiography. High-frame rate, three-beat captures of LA (15-segment model; two-chamber, three-chamber, and four-chamber views) and RA (six-segment model; four-chamber view) were analyzed (Vivid 7, EchoPAC BT11). LA and RA segmental and global peak positive ε (εPos) and negative ε (εNeg) and peak positive SR, early negative SR, and late negative SR were measured. Linear and nonlinear regressions of ε and SR were performed with age and heart rate. Relationships of ε and SR with ventricular inflow Doppler and myocardial tissue Doppler indices were explored. The age range was 3 days to 20 years, and body surface area range from 0.17 to 2.3 m(2) for the study cohort. Mean global LA εPos, LA εNeg, RA εPos, and RA εNeg were 28 ± 9%, -16 ± 6%, 23 ± 9%, and -15 ± 6%, respectively. Positive correlations were found for global atrial εPos and εNeg with age (P < .001). A marked rate of changes in ε and SR was seen in the first year of life, reaching normal adult values by adolescence. Peak positive SR had a strong negative correlation with age, and early negative SR had a strong positive correlation with age (P < .001), while late negative SR was correlated nonlinearly. Heart rate and age both influenced all LA and RA ε and SR indices. Maturational changes in LA and RA ε and SR occur in normal children and are especially profound in infancy. Consequently, LA and RA performance indices must be interpreted in light of heart rate and age. Normal values and percentiles for atrial ε and SR reported here will provide a foundation for the study of pediatric atrial physiology and function in disease states.
Our purpose was to evaluate yield of tools commonly advocated for surveillance of tetralogy of Fa... more Our purpose was to evaluate yield of tools commonly advocated for surveillance of tetralogy of Fallot (TOF). All patients (pts) with TOF, seen at any time from 1/2008 to 9/2013 in an academic cardiology practice were studied. At the first and each subsequent outpatient visit, the use of tools including history and physical (H&P), ECG, Holter (HOL), echocardiogram (Echo), MR or CT (MR-CT) and stress testing (STR) were noted. Recommendations for intervention (INT) and for time to next follow-up were recorded; rationale for each INT with attribution to one or more tools was identified. There were 213 pts (mean 11.5 years, 130 male) who had 916 visits, 123 of which (13.4%) were associated with 138 INTs (47 surgical, 54 catheter-mediated, 37 other medical). Recommended follow-up interval was 9.44±6.5 months, actual mean follow-up interval was 11.7 months. All 916 (100%) patient visits had a H&P which contributed to 47.2% of INT decisions. Echo was performed in 652 (71.2%) of visits, and ...
To derive and validate a multivariate stratification model for prediction of survival free from i... more To derive and validate a multivariate stratification model for prediction of survival free from intervention (SFFI) in ventricular septal defect (VSD). A secondary aim is for this model to serve as proof of concept for derivation of a more general congenital heart disease prognostic model, of which the VSD model will be the first component. For 12 years, 2334 subjects with congenital heart disease were prospectively and consecutively enrolled. Of these, 675 had VSD and form the derivation cohort. One hundred seven other subjects with VSD followed in another practice formed the validation cohort. The derivation cohort was serially stratified based on clinical and demographic features correlating with SFFI. Six strata were defined, the most favorable predicting nearly 100% SFFI at 10 years, and the least favorable, a high likelihood of event within weeks. Strata with best SFFI had many subjects with nearly normal physiology, muscular VSD location, or prior intervention. In the validation cohort, the relation between predicted and actual SFFI at 6 months, 1 year, 2 years, and 5 years follow-up had areas under the receiver operating characteristic curves 0.800 or greater. A prediction model for SFFI in VSD has been derived and validated. It has potential for clinical application to the benefit of patients and families, medical trainees, and practicing physicians.
Journal of the American Society of Echocardiography, 2015
Predischarge (pre-d/c) transthoracic echocardiography (TTE) is routine after surgery for congenit... more Predischarge (pre-d/c) transthoracic echocardiography (TTE) is routine after surgery for congenital heart disease, but how it affects clinical care is unknown. The aim of this study was to test the hypothesis that pre-d/c TTE frequently reveals findings associated with short-term clinical course through a systematic review of findings on pre-d/c TTE and clinical events that followed. Clinical outcomes of mortality, hospitalization, catheterization, and surgery at 1 year were examined for pediatric patients undergoing pre-d/c TTE between June 2010 and June 2012. Using logistic regression, a multivariate model was generated associating clinical, pre-d/c transthoracic echocardiographic, and demographic variables with unplanned postdischarge cardiac events (UCEs) within 1 year. Of 462 patients who underwent pre-d/c TTE, there were 265 male patients (57%) and 197 female patients (43%); the median age was 0.8 years (range, 0-33 years). Two hundred thirty-seven patients (51%) had findings (valve regurgitation, hemodynamic obstruction, ventricular dysfunction, unintended shunt, or pericardial effusion) on pre-d/c TTE, 57 of which were of more than mild severity. Agreement between pre-d/c TTE and postoperative transesophageal echocardiographic findings was only fair to moderate (κ = 0.27-0.43). Sixty-four patients (14%) had UCEs. Univariate analysis revealed that UCE were more frequent in patients with diagnoses and surgical procedures of high complexity. After accounting for these confounding nonechocardiographic variables, pre-d/c transthoracic echocardiographic findings, specifically valve regurgitation of more than mild severity, and ventricular dysfunction and obstructions of any severity were independently associated with UCEs (odds ratios, 1.90, 1.99, and 1.85, respectively). Findings on pre-d/c TTE are frequent, commonly discordant with postoperative transesophageal echocardiographic results, and associated with adverse clinical events after surgery for congenital heart disease. These data would strongly support the practice of pre-d/c TTE after surgery for congenital heart disease.
We present the anatomic constellation of mitral stenosis/aortic atresia variant of hypoplastic le... more We present the anatomic constellation of mitral stenosis/aortic atresia variant of hypoplastic left heart syndrome, Ebstein's anomaly, and partial anomalous pulmonary venous return, an exceeding rare congenital heart defect. Prenatal echocardiography led to concern about the capacity of the right ventricle to increase cardiac output with lung expansion and pulmonary arterial runoff at birth, prompting the precaution of extracorporeal membrane oxygenator standby at delivery. Stage I palliation was not attempted, and control of pulmonary arterial blood flow was achieved with pulmonary artery banding, allowing sufficient ongoing hemodynamic stability. Orthotopic cardiac transplantation, repair of hypoplastic aortic arch, and primary sutureless repair of left pulmonary veins was performed, using dual-site arterial cannulation and continuous mild hypothermic cardiopulmonary bypass. We discuss how this unique echocardiographic anatomy influenced the surgical decision and point out how...
World journal for pediatric & congenital heart surgery, Jan 23, 2014
We describe a relatively long left ventricular recruitment pathway consisting of early and serial... more We describe a relatively long left ventricular recruitment pathway consisting of early and serial aortic valvuloplasties and multiple endocardial fibroelastosis resections resulting in successful biventricular conversion of hypoplastic left heart syndrome.
European heart journal cardiovascular Imaging, 2012
We sought to evaluate the efficacy of ultrasound contrast (UC) and low mechanical index real-time... more We sought to evaluate the efficacy of ultrasound contrast (UC) and low mechanical index real-time perfusion (RTP) in the haemodynamic and anatomic assessment of repaired congenital heart disease (CHD) at rest and during supine bicycle stress echocardiography (BSE). Patients with CHD (n = 51, median age 21.5 years) were prospectively studied. All had compromised image quality, 20 (39%) had arrhythmias, and 10 (20%) had pacemakers. RTP was performed at rest and during BSE using Definity and Contrast Pulse Sequencing, with assessment of Doppler pressure gradients. Diagnoses included tetralogy of Fallot (n = 27), transposition of the great arteries (TGA) atrial switch (n = 10), TGA arterial switch (n = 2), aortic valve disease (n = 4), Fontan (n = 4), and Kawasaki disease (n = 4). UC with RTP improved endocardial border definition, with increased number of left ventricular (LV) and right ventricular (RV) segments visualized at rest (P < 0.0001) and during stress. LV ejection fraction...
Journal of the American Society of Echocardiography, 2014
Background: The purpose of this investigation was to test the hypothesis that flow patterns in th... more Background: The purpose of this investigation was to test the hypothesis that flow patterns in the right ventricle are abnormal in patients with repaired tetralogy of Fallot (TOF). High-resolution echocardiographic contrast particle imaging velocimetry was used to investigate rotation intensity and kinetic energy dissipation of right ventricular (RV) flow in patients with TOF compared with normal controls.
Our purpose was to test the following hypotheses: (1) patients with hypoplastic left heart syndro... more Our purpose was to test the following hypotheses: (1) patients with hypoplastic left heart syndrome who develop significant tricuspid regurgitation (TR) or require tricuspid valve (TV) surgery in the medium term have detectable TV abnormalities by 3-dimensional echocardiography (3DE) prestage 1 palliation and (2) TR is associated with reduced survival and increased TV intervention. Infants were prospectively studied with 3DE and 2DE prestage 1 and followed up for the end points of TR, TV surgery, transplantation, or death. From prestage 1 3DE, spatial coordinates of TV annulus and leaflets were extracted; annulus size, leaflet area, prolapse volume, tethering volume, bending angle, and papillary muscle angle were measured. TR was assessed prestage 1 and at latest follow-up. Of 70 patients, 62 (88.6%) had mild or less TR and 8 (11.4%) had moderate or greater TR prestage 1. Prestage 1 tethering volume correlated to leaflet area (r=0.736; P<0.001), annulus area (r=0.651; P<0.001)...
Palliative shunts in congenital heart disease patients are vulnerable to thrombotic occlusion. Hi... more Palliative shunts in congenital heart disease patients are vulnerable to thrombotic occlusion. High mechanical index (MI) impulses from a modified diagnostic ultrasound (US) transducer during a systemic microbubble (MB) infusion have been used to dissolve intravascular thrombi without anticoagulation, and we sought to determine whether this technique could be used prophylactically to reduce thrombus burden and prevent occlusion of surgically placed extracardiac shunts. Heparin-bonded ePTFE tubular vascular shunts of 4 mm×2.5 cm (Propaten; W.L Gore) were surgically placed in 18 pigs: a right-sided side-to-side arteriovenous (AV, carotid-jugular) shunt, and a left-sided arterio-arterial (AA, carotid-carotid) interposition shunt in each animal. After shunt implantation, animals were randomly assigned to one of 3 groups. Transcutaneous, weekly 30-minute treatments (total of 4 treatments) of either guided high MI US+MB (Group 1; n=6) using a 3% MRX-801 MB infusion, or US alone (Group 2; ...
Main pulmonary artery (MPA) dilation is reported to occur in association with pulmonary valve (PV... more Main pulmonary artery (MPA) dilation is reported to occur in association with pulmonary valve (PV) abnormalities and in genetic diseases of connective tissue. To determine whether MPA dilation occurs with bicuspid aortic valve (BAV) in the absence of PV abnormality. MPA and aortic dimensions were investigated in 194 subjects with BAV and 178 controls matched for age, sex and body surface area (BSA) using transthoracic two-dimensional echocardiography. Using control measurements, linear regression of each parameter versus age, gender, and BSA(2/3) provided expected values. For each subject with BAV, the percentage divergence from expected value ((observed--expected value)/expected value) for each dimension was analysed. MPA and aortic measurements showed normal distribution in all subjects. PV annulus and MPA were larger in BAV; 17.7% positive divergence of MPA dimension from expected was found in diastole, and 16.7% in systole. Aortic dimensions at all levels measured were larger in BAV; divergence was greater distally than proximally (10% divergence at annulus, 31% at ascending aorta). In BAV, divergence of ascending aortic dimensions from expected values increased with age (r(2)=0.142, p=0.02), but MPA divergence from expected values did not increase with age (r(2)=0.001, p=0.296). MPA dilation occurs in association with BAV in the absence of PV abnormality, suggesting primary vessel wall pathology predisposing to arterial dilation. A systemic abnormality of connective tissue common to both arteries may be responsible, or the dilation may result from a common developmental exposure as both originate from the embryologic cono-truncus.
Journal of Thoracic and Cardiovascular Surgery, 2006
Objective: Robotic systems allow surgeons to perform minimally invasive cardiac surgery in adults... more Objective: Robotic systems allow surgeons to perform minimally invasive cardiac surgery in adults. Experience in the pediatric population, however, is limited. Perventricular closure of muscular ventricular septal defects has been reported in humans but requires a median sternotomy. The objective of this study was to assess the feasibility of robotically assisted closure of perimembranous ventricular septal defects by using the perventricular approach.
The Journal of thoracic and cardiovascular surgery, Jan 28, 2015
We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan o... more We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan operation. We aimed to measure hepatic stiffness using ultrasound and shear wave elastography (SWE) in a bidirectional cavopulmonary connection (BCPC) cohort. Subjects were prospectively recruited for real-time, hepatic, ultrasound-SWE for hepatic stiffness (kPa) and echocardiography. Doppler velocities, a velocity-time integral, flow volume, and resistive index, pulsatility index, and acceleration index were measured in celiac and superior mesenteric arteries, and in the main portal vein (MPV). Comparisons were made among subjects who had BCPC, subjects who were healthy, and a cohort of patients who had undergone the Fontan procedure. Forty subjects (20 patients who had BCPC; 20 age- and gender-matched control subjects) were studied. The hepatic stiffness in BCPC was elevated, compared with that in control subjects (7.2 vs 5.7 kPa; P = .039). Patients who had BCPC had significantly highe...
Left atrial (LA) function is an important modulator of left ventricular filling and has a prognos... more Left atrial (LA) function is an important modulator of left ventricular filling and has a prognostic role in adult heart failure, but pediatric data are limited. The aim of this study was to characterize the normal LA and right atrial (RA) strain (ε) and strain rate (SR) in infants and children. Atrial ε and SR were prospectively investigated in 153 subjects using two-dimensional speckle-tracking echocardiography. High-frame rate, three-beat captures of LA (15-segment model; two-chamber, three-chamber, and four-chamber views) and RA (six-segment model; four-chamber view) were analyzed (Vivid 7, EchoPAC BT11). LA and RA segmental and global peak positive ε (εPos) and negative ε (εNeg) and peak positive SR, early negative SR, and late negative SR were measured. Linear and nonlinear regressions of ε and SR were performed with age and heart rate. Relationships of ε and SR with ventricular inflow Doppler and myocardial tissue Doppler indices were explored. The age range was 3 days to 20 years, and body surface area range from 0.17 to 2.3 m(2) for the study cohort. Mean global LA εPos, LA εNeg, RA εPos, and RA εNeg were 28 ± 9%, -16 ± 6%, 23 ± 9%, and -15 ± 6%, respectively. Positive correlations were found for global atrial εPos and εNeg with age (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). A marked rate of changes in ε and SR was seen in the first year of life, reaching normal adult values by adolescence. Peak positive SR had a strong negative correlation with age, and early negative SR had a strong positive correlation with age (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001), while late negative SR was correlated nonlinearly. Heart rate and age both influenced all LA and RA ε and SR indices. Maturational changes in LA and RA ε and SR occur in normal children and are especially profound in infancy. Consequently, LA and RA performance indices must be interpreted in light of heart rate and age. Normal values and percentiles for atrial ε and SR reported here will provide a foundation for the study of pediatric atrial physiology and function in disease states.
Our purpose was to evaluate yield of tools commonly advocated for surveillance of tetralogy of Fa... more Our purpose was to evaluate yield of tools commonly advocated for surveillance of tetralogy of Fallot (TOF). All patients (pts) with TOF, seen at any time from 1/2008 to 9/2013 in an academic cardiology practice were studied. At the first and each subsequent outpatient visit, the use of tools including history and physical (H&P), ECG, Holter (HOL), echocardiogram (Echo), MR or CT (MR-CT) and stress testing (STR) were noted. Recommendations for intervention (INT) and for time to next follow-up were recorded; rationale for each INT with attribution to one or more tools was identified. There were 213 pts (mean 11.5 years, 130 male) who had 916 visits, 123 of which (13.4%) were associated with 138 INTs (47 surgical, 54 catheter-mediated, 37 other medical). Recommended follow-up interval was 9.44±6.5 months, actual mean follow-up interval was 11.7 months. All 916 (100%) patient visits had a H&P which contributed to 47.2% of INT decisions. Echo was performed in 652 (71.2%) of visits, and ...
To derive and validate a multivariate stratification model for prediction of survival free from i... more To derive and validate a multivariate stratification model for prediction of survival free from intervention (SFFI) in ventricular septal defect (VSD). A secondary aim is for this model to serve as proof of concept for derivation of a more general congenital heart disease prognostic model, of which the VSD model will be the first component. For 12 years, 2334 subjects with congenital heart disease were prospectively and consecutively enrolled. Of these, 675 had VSD and form the derivation cohort. One hundred seven other subjects with VSD followed in another practice formed the validation cohort. The derivation cohort was serially stratified based on clinical and demographic features correlating with SFFI. Six strata were defined, the most favorable predicting nearly 100% SFFI at 10 years, and the least favorable, a high likelihood of event within weeks. Strata with best SFFI had many subjects with nearly normal physiology, muscular VSD location, or prior intervention. In the validation cohort, the relation between predicted and actual SFFI at 6 months, 1 year, 2 years, and 5 years follow-up had areas under the receiver operating characteristic curves 0.800 or greater. A prediction model for SFFI in VSD has been derived and validated. It has potential for clinical application to the benefit of patients and families, medical trainees, and practicing physicians.
Journal of the American Society of Echocardiography, 2015
Predischarge (pre-d/c) transthoracic echocardiography (TTE) is routine after surgery for congenit... more Predischarge (pre-d/c) transthoracic echocardiography (TTE) is routine after surgery for congenital heart disease, but how it affects clinical care is unknown. The aim of this study was to test the hypothesis that pre-d/c TTE frequently reveals findings associated with short-term clinical course through a systematic review of findings on pre-d/c TTE and clinical events that followed. Clinical outcomes of mortality, hospitalization, catheterization, and surgery at 1 year were examined for pediatric patients undergoing pre-d/c TTE between June 2010 and June 2012. Using logistic regression, a multivariate model was generated associating clinical, pre-d/c transthoracic echocardiographic, and demographic variables with unplanned postdischarge cardiac events (UCEs) within 1 year. Of 462 patients who underwent pre-d/c TTE, there were 265 male patients (57%) and 197 female patients (43%); the median age was 0.8 years (range, 0-33 years). Two hundred thirty-seven patients (51%) had findings (valve regurgitation, hemodynamic obstruction, ventricular dysfunction, unintended shunt, or pericardial effusion) on pre-d/c TTE, 57 of which were of more than mild severity. Agreement between pre-d/c TTE and postoperative transesophageal echocardiographic findings was only fair to moderate (κ = 0.27-0.43). Sixty-four patients (14%) had UCEs. Univariate analysis revealed that UCE were more frequent in patients with diagnoses and surgical procedures of high complexity. After accounting for these confounding nonechocardiographic variables, pre-d/c transthoracic echocardiographic findings, specifically valve regurgitation of more than mild severity, and ventricular dysfunction and obstructions of any severity were independently associated with UCEs (odds ratios, 1.90, 1.99, and 1.85, respectively). Findings on pre-d/c TTE are frequent, commonly discordant with postoperative transesophageal echocardiographic results, and associated with adverse clinical events after surgery for congenital heart disease. These data would strongly support the practice of pre-d/c TTE after surgery for congenital heart disease.
We present the anatomic constellation of mitral stenosis/aortic atresia variant of hypoplastic le... more We present the anatomic constellation of mitral stenosis/aortic atresia variant of hypoplastic left heart syndrome, Ebstein's anomaly, and partial anomalous pulmonary venous return, an exceeding rare congenital heart defect. Prenatal echocardiography led to concern about the capacity of the right ventricle to increase cardiac output with lung expansion and pulmonary arterial runoff at birth, prompting the precaution of extracorporeal membrane oxygenator standby at delivery. Stage I palliation was not attempted, and control of pulmonary arterial blood flow was achieved with pulmonary artery banding, allowing sufficient ongoing hemodynamic stability. Orthotopic cardiac transplantation, repair of hypoplastic aortic arch, and primary sutureless repair of left pulmonary veins was performed, using dual-site arterial cannulation and continuous mild hypothermic cardiopulmonary bypass. We discuss how this unique echocardiographic anatomy influenced the surgical decision and point out how...
World journal for pediatric & congenital heart surgery, Jan 23, 2014
We describe a relatively long left ventricular recruitment pathway consisting of early and serial... more We describe a relatively long left ventricular recruitment pathway consisting of early and serial aortic valvuloplasties and multiple endocardial fibroelastosis resections resulting in successful biventricular conversion of hypoplastic left heart syndrome.
European heart journal cardiovascular Imaging, 2012
We sought to evaluate the efficacy of ultrasound contrast (UC) and low mechanical index real-time... more We sought to evaluate the efficacy of ultrasound contrast (UC) and low mechanical index real-time perfusion (RTP) in the haemodynamic and anatomic assessment of repaired congenital heart disease (CHD) at rest and during supine bicycle stress echocardiography (BSE). Patients with CHD (n = 51, median age 21.5 years) were prospectively studied. All had compromised image quality, 20 (39%) had arrhythmias, and 10 (20%) had pacemakers. RTP was performed at rest and during BSE using Definity and Contrast Pulse Sequencing, with assessment of Doppler pressure gradients. Diagnoses included tetralogy of Fallot (n = 27), transposition of the great arteries (TGA) atrial switch (n = 10), TGA arterial switch (n = 2), aortic valve disease (n = 4), Fontan (n = 4), and Kawasaki disease (n = 4). UC with RTP improved endocardial border definition, with increased number of left ventricular (LV) and right ventricular (RV) segments visualized at rest (P < 0.0001) and during stress. LV ejection fraction...
Journal of the American Society of Echocardiography, 2014
Background: The purpose of this investigation was to test the hypothesis that flow patterns in th... more Background: The purpose of this investigation was to test the hypothesis that flow patterns in the right ventricle are abnormal in patients with repaired tetralogy of Fallot (TOF). High-resolution echocardiographic contrast particle imaging velocimetry was used to investigate rotation intensity and kinetic energy dissipation of right ventricular (RV) flow in patients with TOF compared with normal controls.
Our purpose was to test the following hypotheses: (1) patients with hypoplastic left heart syndro... more Our purpose was to test the following hypotheses: (1) patients with hypoplastic left heart syndrome who develop significant tricuspid regurgitation (TR) or require tricuspid valve (TV) surgery in the medium term have detectable TV abnormalities by 3-dimensional echocardiography (3DE) prestage 1 palliation and (2) TR is associated with reduced survival and increased TV intervention. Infants were prospectively studied with 3DE and 2DE prestage 1 and followed up for the end points of TR, TV surgery, transplantation, or death. From prestage 1 3DE, spatial coordinates of TV annulus and leaflets were extracted; annulus size, leaflet area, prolapse volume, tethering volume, bending angle, and papillary muscle angle were measured. TR was assessed prestage 1 and at latest follow-up. Of 70 patients, 62 (88.6%) had mild or less TR and 8 (11.4%) had moderate or greater TR prestage 1. Prestage 1 tethering volume correlated to leaflet area (r=0.736; P<0.001), annulus area (r=0.651; P<0.001)...
Palliative shunts in congenital heart disease patients are vulnerable to thrombotic occlusion. Hi... more Palliative shunts in congenital heart disease patients are vulnerable to thrombotic occlusion. High mechanical index (MI) impulses from a modified diagnostic ultrasound (US) transducer during a systemic microbubble (MB) infusion have been used to dissolve intravascular thrombi without anticoagulation, and we sought to determine whether this technique could be used prophylactically to reduce thrombus burden and prevent occlusion of surgically placed extracardiac shunts. Heparin-bonded ePTFE tubular vascular shunts of 4 mm×2.5 cm (Propaten; W.L Gore) were surgically placed in 18 pigs: a right-sided side-to-side arteriovenous (AV, carotid-jugular) shunt, and a left-sided arterio-arterial (AA, carotid-carotid) interposition shunt in each animal. After shunt implantation, animals were randomly assigned to one of 3 groups. Transcutaneous, weekly 30-minute treatments (total of 4 treatments) of either guided high MI US+MB (Group 1; n=6) using a 3% MRX-801 MB infusion, or US alone (Group 2; ...
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Papers by David Danford