Thomas Lloyd | University of Michigan (original) (raw)

Papers by Thomas Lloyd

Research paper thumbnail of In vivo relation between cineangiographic jet width and jet width imaged by color-coded Doppler

The American Journal of Cardiology, Dec 1, 1989

menisci, consistent with chronic small peripheral pulmonary emboli. This patient was treated empi... more menisci, consistent with chronic small peripheral pulmonary emboli. This patient was treated empirically with long-term oral anticoagulation. Pathologic evaluation did not reveal pulmonary emboli, plexogenic lesions or venoocclusive disease in 2 other patients. Other evidence against veno-occlusive disease included the lack of Kerley B lines on chest radiographs, absence of regional differences in pulmonary capillary wedge pressure and similar sizes of the pulmonary arteries and veins by computed tomography scan.

Research paper thumbnail of Rhinocerebral mucormycosis in an infant with streptococcal sepsis and purpura fulminans

Research paper thumbnail of Transcatheter Closure of Atrial Septal Defects

Journal of Interventional Cardiology, Sep 30, 1995

The first transcatheter closure of an atrial septal defect (ASD) was performed by King and Mills ... more The first transcatheter closure of an atrial septal defect (ASD) was performed by King and Mills in 1976. The Lock Cfunishell occluder and flze hi4ttooned &lice are the latest devices to undergo clitziwl trials. Successful transcaihefer closure hus been possible with minimal morbidity and mortality. Small residual shunts may remain, however. in up to 20% of patients 1 year after the procedure. The clinic-a1 signifc8unce and natural history qf these small residuul atrid commiinirutinns remains to be determined. This article reviews the history and development of the current ASD closure techniques, with emphasis on the experience with the L,ock Clumshell orl-luder and the hitttoned device. (J Interven Cardiol 1995;8:533-542) delivery system in positioning the device parallel to the atrial septum, were additional liabilities of the Rashkind devicc.

Research paper thumbnail of Trans-hepatic cannulation: A novel approach for placement of a pediatric percutaneous ventricular assist device

Asaio Journal, Sep 1, 2006

Pediatric ventricular assist device (VAD) use is increasing. The TandemHeart PTVA system is a per... more Pediatric ventricular assist device (VAD) use is increasing. The TandemHeart PTVA system is a percutaneous VAD used in adults. Pediatric use is limited by cannula size. Trans-hepatic left atrial (LA) cannulation offers the possibility of shorter, larger-diameter cannulae, but specific requirements for cannula size and flow characteristics need to be developed. We evaluated the feasibility of trans-hepatic cannulation based on patient measurements and bench-top modeling. Two hundred patients admitted to the University of Michigan Pediatric CICU were evaluated. Patients over 14 years and dextrocardiac patients were excluded. The distance from the skin between the 10th and 11th ribs at the mid-axillary line to the left-heart border was measured on x-ray. LA size was measured on echocardiogram. From these measurements, prototype cannulae were fabricated. Benchtop testing of developed cannulae was performed with a pump speed of 8500 RPM and fluid viscosity of 4.0 cP at physiologic atrial and arterial pressures. Inlet pressure and deliverable flows were measured. The proposed design delivered sufficient flow with negative pressures low enough to avoid hemolysis. Trans-hepatic LA cannulation for percutaneous VAD placement is feasible. The shorter distance to the LA and larger hepatic vein size allows design of pediatric-appropriate cannulae with adequate flow rates.

Research paper thumbnail of Intraoperative and percutaneous stenting of congenital pulmonary artery and vein stenosis

Circulation, 1993

Conventional surgical or balloon dilation therapy for pulmonary artery or vein stenosis has been ... more Conventional surgical or balloon dilation therapy for pulmonary artery or vein stenosis has been unsatisfactory in many patients. Balloon-expandable stents offer a new form of treatment for these vascular stenoses and can be implanted percutaneously or intraoperatively. Between July 1991 and October 1992, 20 balloon-expandable Palmaz stents (Johnson & Johnson) were implanted in 16 children at median age and weight of 3.0 years and 12.8 kg, respectively. Stent implantation was performed intraoperatively (n = 15) if the patient was less than 1 year of age or less than 10 kg in weight, in cases where limited vascular access precluded percutaneous implantation, or as an adjunct to other intracardiac surgery. Otherwise, percutaneous stenting was performed (n = 5). Vessels were tested for distensibility by dilation with balloon catheters or vascular sounds. Stents were implanted using angioplasty catheter balloons chosen to achieve desired vessel diameter and inflated to 4 to 17 atm. Acut...

Research paper thumbnail of Central pulmonary artery growth patterns after the bidirectional Glenn procedure

The Journal of thoracic and cardiovascular surgery, 1994

The changes in pulmonary artery size and hemodynamics in 30 patients with univentricular cardiac ... more The changes in pulmonary artery size and hemodynamics in 30 patients with univentricular cardiac anatomy were examined before and after bidirectional Glenn procedures done between October 1989 and February 1992. Serial angiographic and hemodynamic examinations before and 17.6 +/- 1.6 months after bidirectional Glenn procedures were compared. At the follow-up study there was no significant change in diameter of the pulmonary artery ipsilateral to the bidirectional Glenn shunt, however, a significant decrease was noted in the diameter of the pulmonary artery contralateral to the bidirectional Glenn shunt (p = 0.04). There was also a 32% decrease in the Nakata index of total cross-sectional pulmonary artery area after the bidirectional Glenn procedure (p = 0.004). Total pulmonary blood flow and mean pulmonary artery pressure had decreased, and arterial oxygen saturation had increased at follow-up. These changes, however, did not correlate with the observed changes in pulmonary artery s...

Research paper thumbnail of Pediatric cardiology outcomes research using an intervention-specific registry: the PDA Coil Registry

The PDA Coil Registry was organized in 1994 as an open, voluntary, multicenter registry of data o... more The PDA Coil Registry was organized in 1994 as an open, voluntary, multicenter registry of data on coil occlusion of patent ductus arteriosus. In the less than two years in which new patients were recruited, over 1300 procedures were reported to the registry. To encourage participation, the registry limited the amount of data to be reported, requested only data which would be collected for clinical purposes, and separated reporting of the initial procedure from the submission of follow-up data. The PDA Coil Registry is an example of an intervention-specific registry which was able to gather substantial data for carefully focused outcomes research in a limited period of time with a modest investment of resources. 0 1997 Elsevier Science Ireland Ltd.

Research paper thumbnail of Acc/Aha/Aap Recommendations for Training in Pediatric Cardiology

PEDIATRICS, 2005

by guest on May 24, 2020 www.aappublications.org/news Downloaded from REFERENCE 1. Beller GA, Bon... more by guest on May 24, 2020 www.aappublications.org/news Downloaded from REFERENCE 1. Beller GA, Bonow RO, Fuster V. ACC revised recommendations for training in adult cardiovascular medicine Core Cardiology Training II (COCATS 2) (revision of the 1995 COCATS training statement). J Am Coll

Research paper thumbnail of Contractile Response to Sympathetic Innervation in Neonatal Ventricular Cardiomyocytes of the Spontaneously Hypertensive Rat

Pediatric Research, 1991

Differences in cardiac development between spontaneously hypertensive rats (SHR) and their normot... more Differences in cardiac development between spontaneously hypertensive rats (SHR) and their normotensive Wistar Kyoto (WKY) controls are observed before the onset of hypertension. To determine whether intrinsic differences in myocardium or autonomic neurons might be responsible for these observations, we studied primary cultures of isolated, never previously innervated ventricular cardiomyocytes from neonatal rats of both strains, and sympathetic innervation was produced by addition of neurons from thoracolumbar sympathetic ganglia. Both samestrain and cross-strain innervation were compared. Amplitude and frequency of contraction were measured from video images of spontaneously contracting cells by on-line video motion analysis. Sympathetic innervation improved contractile function by 61% in SHR cardiomyocytes ( p < 0.001), an effect qualitatively similar to that previously reported for WKY cardiomyocytes. Contractile function of SHR cardiomyocytes cultured without sympathetic explants was 25% less than that of WKY cells ( p < 0.005), but the response of SHR cardiomyocytes to sympathetic innervation was twice as great as that of WKY myocytes ( p < 0.01). Cross-strain innervation experiments showed that sympathetic neurons from both strains were equally effective; interstrain differences were confined to the cardiomyocytes. Interstrain differences in cardiomyocyte contractile function and contractile response to sympathetic innervation are present before the onset of hypertension, and may in part account for alterations in cardiac function observed in prehypertensive SHR. (Pediatr Res 30: 207-210,1991) Abbreviations SHR, spontaneously hypertensive rat WKY, Wistar Kyoto rat Several investigators have documented cardiomyocyte hyperplasia and relative cardiomegaly in newborn SHR compared with the normotensive WKY strain (1-5). Despite SHR cardiomyocyte hyperplasia, cardiac contractility is lower in neonatal SHR than in WKY (3-5), implying that contractile function at the single-cell level is considerably reduced in the SHR. Because

Research paper thumbnail of Failure of color flow mapping to identify coronary artery to pulmonary artery fistula

Pediatric Cardiology, 1991

A case of coronary artery to pulmonary artery fistula presented with the typical clinical finding... more A case of coronary artery to pulmonary artery fistula presented with the typical clinical findings of asymptomatic precordial continuous murmur and small left-to-right shunt. Echocardiography with color flow mapping failed to demonstrate the fistula on three occasions, including one study performed after angiographic demonstration of the fistula site. This case illustrates the importance of angiography in patients with unexplained continuous murmurs, even when echocardiographic and color flow mapping results are normal.

Research paper thumbnail of Total anomalous origin of the coronary arteries from the pulmonary artery

Pediatric Cardiology, 1986

The clinicopathologic features of four patients with total anomalous origin of the coronary arter... more The clinicopathologic features of four patients with total anomalous origin of the coronary arteries from the pulmonary artery (TCAPA) are presented and compared with 21 previously reported cases . Patients with TCAPA usually present with left ventricular heart failure, angina, or associated cardiovascular anomalies . Of the 19 patients in whom a clinical history was available, 16 were symptomatic before three days of age . All patients died with 60% dying before two weeks of age . Longer survival was associated with additional cardiovascular anomalies that increased pulmonary arterial perfusion pressure, oxygen saturation, or both . Seventeen (68%) patients had additional cardiovascular anomalies, most commonly atrial (nine cases) or ventricular (eight cases) septal defects and tetralogy of Fallot or other variants of pulmonary atresia (four cases) . Only five (22%) of 23 had noncardiovascular anomalies . The coronary arteries arose equally from either one ostium or from two, and the number of ostia was not related to either anomalous coronary artery distribution or to the presence of additional cardiovascular anomalies . Cardiomegaly was present in 56% of cases and the majority of patients had myocardial fibrosis or infarction . Embryology is reviewed and evidence is presented to support the theory of involution-persistence of coronary artery anlagen as the pathogenetic mechanism of TCAPA .

Research paper thumbnail of Concealed Atrial Parasystole Following the Senning Operation

Pacing and Clinical Electrophysiology, 1988

YOUNG, M.-L., ET AL.: Concealed atrial parasystole following the Senning operation. A patient wit... more YOUNG, M.-L., ET AL.: Concealed atrial parasystole following the Senning operation. A patient with sick sinus syndrome /oJiowing the Senning operation was also found to have concealed atrial parasystole during intracardiac eJectrophysioJogical study. This atriai parasystolic pattern could he converted to atriaJ bigeminy by changing the atrial drive rate. (PACE, Vol. 11, November 1988} atrial dysrhythmia. congenital heart disease, transposition of the great arteries, parasystole

Research paper thumbnail of Echocardiographic predictors for successful aortic valve replacement with pulmonary autograft (Ross) procedure in children

Journal of the American Society of Echocardiography, 1995

Journal of the American Society of Echocardiography, Volume 8, Issue 3, Pages 402, May 1995, Auth... more Journal of the American Society of Echocardiography, Volume 8, Issue 3, Pages 402, May 1995, Authors:Ohad Ludomirsky; Achi Ludomirsky; Thomas Lloyd; Gerald Serwer; Roger P. Vermilion; Ralph Mosca; Ed Bove. ...

Research paper thumbnail of 783-2 Follow-up After Coil Occlusion of Patent Ductus Arteriosus

Journal of the American College of Cardiology, 1995

Conclusions: 1) Survival analysis estimates 93% complete PDA closure after a single coil occlusio... more Conclusions: 1) Survival analysis estimates 93% complete PDA closure after a single coil occlusion procedure; 2) Residual shunts are associated with larger PDA diameter, and most close spontaneously; and 3) When necessary, a second coil occlusion has been uniformly successful.

Research paper thumbnail of Repeat balloon aortic valvuloplasty: Is it worthwhile?

Journal of the American College of Cardiology, 1996

failure to implant the coil, and by incomplete closure. We report a snareassisted technique wh~l ... more failure to implant the coil, and by incomplete closure. We report a snareassisted technique wh~l optimizes 0oil position for improved occlusion and minimizes dsk of embollzation.

Research paper thumbnail of The PDA coil registry: 250 patient-years of follow-up

Journal of the American College of Cardiology, 1996

It has been suggested that hibernation, a condition of chronic pedusinn-COntraction down-regulati... more It has been suggested that hibernation, a condition of chronic pedusinn-COntraction down-regulation with preserved viability, results from recurrent episodes of reversible ischemia and "chronic" postischemic dysfunction. We examined the interrelation between flow, metalxdism, and function in an acute model of repetitive stunning. Nine dogs underwent four 5 rain balloon occlusions of the LAD or circumflex arteries, each separated by 5 rain of reperfusion. Regional blood flow (BF), metabolism and function were evaluated 2 hourS after reperfusion in 5 dogs, and 2 hours, 24 hours, and 1 week post-reperfual0n in 4 dogs, Regional wall motion 0NM) was evaluated with 2-D echo and 8F with radiotsbalod micraspheres. Measurements of oxidative metabolism (MVO2) and glucose uptake (during hypednsulinemioeuglycemic ¢tsmp) were derived with PET imaging. Regional WM was severely decreased after the 4 Cycles of ischemia, remained severely impaired 2 hours after repertusion, and normalized after 1 week. Dudng reflow, BF in stunned regions was restored to near-normal levels (0.89 • 0,2 vs 0.95:1:0.2 ml/g/min, P < 0.01). Glucose uptake in stunned regions was depressed at 2 hours (73 • 15% of control, P < 0.001) and 24 hours after retiow (80 4-7% of ~ontrel, P = 0.04), but recovered after I week (100 • 26°/= of control, P = NS), Similarly, MVO2 in stunned regions was decreased at 2 hours (84 :E 7% of COntrol, P < 0.001 ) and at 24 hours (8~) :E 6% of COntrol, P = 0.02), and recovered 1 week after reperfusion (97 • 3% of COntrol, P = NS). Thus, repetitive stunned myocardium demonal~tod a persistent reduction of both MVO2 and glucose uptake which recovered as regional wall motion improved. The resu~ may have important implk;ations for detecting stunning in patients with CAD and further suggest a unique metabolic adaptation in "chronic stunning ~, different from that typically seen in hibemalion. ~ Tc-99m.Labeled Ap4A for Early Gamma Scintigrephlc Visualization of Experimental Athemscleroti¢ Lesions Substances related to ATP such as diadenosine tetraphosphate (Ap4A) bind to purina receptors in vascular smooth muscle o~IL Since proliferating smooth muscle cells are an obligatory COmponent of atherosolerotic lesions, T¢-99m-Ap4A was used to assess whether puflne receptors are upregutsted and can detect atherosclerottc lesions in vive.

Research paper thumbnail of Effect of intralipid on the neonatal pulmonary bed: An echographic study

The Journal of Pediatrics, 1986

The effect of !ntralipid infusion on pulmonary vascular resistance was studied prospectively by s... more The effect of !ntralipid infusion on pulmonary vascular resistance was studied prospectively by serial echocardiography on 13 occasions in six low birth weight infants. After 90 minutes of Intralipid infusion, the ratio of right ventricular preejection period to ejection time (RVPEP/ET) rose from 0.232 _+ 0.025 (mean • SD) to 0.285 _+ 0.035 (P = 0.0001). Of the 13 infusions studied, six (43%) resulted in RVPEP/ET values suggestive of pulmonary hypertension. Six LBW infants were observed over the same time period without Intralipid infusion, and RVPEP/ET did not change (0.209 • 0.035 vs 0.194 • 0.024). The increase in RVPEP/ET with Intraiipid administration could not be explained by differences in preload or contractility, and most likely reflects an increase in pulmonary vascular tone. Caution in the use of Intralipid is recommended in infants who would be at particular risk from increased pulmonary vascular resistance. (J PEDIATR 1986;I08:130-133)

Research paper thumbnail of Accuracy of central venous pressure monitoring in the intraabdominal inferior vena cava: A canine study

The Journal of Pediatrics, 1992

To test the hypotheses that in multiple pathophysiologic settings (1) end-expiratory central veno... more To test the hypotheses that in multiple pathophysiologic settings (1) end-expiratory central venous pressure measurements in the intraabdominal inferior vena cava accurately reflect those in the superior vena cava and (2) mean central venous pressure monitoring is as reliable in the inferior vena cava as it is in the superior vena cava. Simultaneous inferior vena caval and superior vena caval pressures were measured during five ventilatory phases: apnea, end-expiratory mechanical ventilation, maximal inspiratory mechanical ventilation, end-expiratory spontaneous ventilation, and maximal inspiratory spontaneous ventilation. Measurements were repeated after progressive intravascular volume depletion. Eight puppies. Simultaneous inferior vena caval and superior vena caval end-expiratory pressures did not differ significantly (mean differences 0 to 0.1 mm Hg) and the limits of agreement of these measurements were within 2 mm Hg. Differences between mean maximal inspiratory pressures in the inferior vena cava and superior vena cava during mechanical and spontaneous ventilation were -0.7 and 3.6 mm Hg, respectively (p less than 0.01), and the limits of agreement extended beyond 2 mm Hg. Furthermore, mean maximal inspiratory pressures in the superior vena cava differed from end-expiratory pressures in the superior vena cava (1.1 and -3.6 mm Hg, p less than 0.01), whereas those in the inferior vena cava did not differ from end-expiratory superior vena caval pressures. Under the experimental conditions studied (1) end-expiratory intraabdominal inferior vena caval pressures accurately reflected end-expiratory superior vena caval pressures and (2) mean central venous pressure monitoring was as reliable in the inferior vena cava as in the superior vena cava.

Research paper thumbnail of Sympathetic innervation improves the contractile performance of neonatal cardiac ventricular myocytes in culture

Journal of Molecular and Cellular Cardiology, 1990

We propose that sympathetic innervation could contribute to the improvement in cardiac contractil... more We propose that sympathetic innervation could contribute to the improvement in cardiac contractility that normally occurs during neonatal life because these processes are developmentally coincident. Effects of sympathetic innervation were studied in primary cultures of isolated, not previously innervated ventricular cardiomyocytes from neonatal rats. Innervation was produced by addition of autologous neurons from the thoracolumbar sympathetic ganglia, and amplitude and frequency of myocyte contraction were measured by on-line video motion analysis. Sympathetic innervation significantly (P less than 0.0001) increased amplitude of contraction (by 34 +/- 8%) and decreased contraction frequency (by 36 +/- 3%). The effect of innervation on myocyte contractility was not attenuated by adrenoceptor blockade (10(-6) M propranolol and 10(-6) M phentolamine), but could be reproduced using medium conditioned by cocultures of neurons and myocytes. Sympathetic innervation improves the contractility of isolated cardiomyocytes, indicating that autonomic innervation contributes to maturation of cardiac function.

Research paper thumbnail of Identification of Coronary Artery to Right Ventricular Fistulae by Color Flow Mapping

Echocardiography, 1988

Page 1. CASE REPORTS Identification of Coronary Artery to Right Ventricular Fistulae by Color Flo... more Page 1. CASE REPORTS Identification of Coronary Artery to Right Ventricular Fistulae by Color Flow Mapping THOMAS R. LLOYD, MD, LARRY T. MAHONEY, MD, WILLIAM J. MARVIN, JR., MD, and DIANA KNOEDEL, PA-C ...

Research paper thumbnail of In vivo relation between cineangiographic jet width and jet width imaged by color-coded Doppler

The American Journal of Cardiology, Dec 1, 1989

menisci, consistent with chronic small peripheral pulmonary emboli. This patient was treated empi... more menisci, consistent with chronic small peripheral pulmonary emboli. This patient was treated empirically with long-term oral anticoagulation. Pathologic evaluation did not reveal pulmonary emboli, plexogenic lesions or venoocclusive disease in 2 other patients. Other evidence against veno-occlusive disease included the lack of Kerley B lines on chest radiographs, absence of regional differences in pulmonary capillary wedge pressure and similar sizes of the pulmonary arteries and veins by computed tomography scan.

Research paper thumbnail of Rhinocerebral mucormycosis in an infant with streptococcal sepsis and purpura fulminans

Research paper thumbnail of Transcatheter Closure of Atrial Septal Defects

Journal of Interventional Cardiology, Sep 30, 1995

The first transcatheter closure of an atrial septal defect (ASD) was performed by King and Mills ... more The first transcatheter closure of an atrial septal defect (ASD) was performed by King and Mills in 1976. The Lock Cfunishell occluder and flze hi4ttooned &lice are the latest devices to undergo clitziwl trials. Successful transcaihefer closure hus been possible with minimal morbidity and mortality. Small residual shunts may remain, however. in up to 20% of patients 1 year after the procedure. The clinic-a1 signifc8unce and natural history qf these small residuul atrid commiinirutinns remains to be determined. This article reviews the history and development of the current ASD closure techniques, with emphasis on the experience with the L,ock Clumshell orl-luder and the hitttoned device. (J Interven Cardiol 1995;8:533-542) delivery system in positioning the device parallel to the atrial septum, were additional liabilities of the Rashkind devicc.

Research paper thumbnail of Trans-hepatic cannulation: A novel approach for placement of a pediatric percutaneous ventricular assist device

Asaio Journal, Sep 1, 2006

Pediatric ventricular assist device (VAD) use is increasing. The TandemHeart PTVA system is a per... more Pediatric ventricular assist device (VAD) use is increasing. The TandemHeart PTVA system is a percutaneous VAD used in adults. Pediatric use is limited by cannula size. Trans-hepatic left atrial (LA) cannulation offers the possibility of shorter, larger-diameter cannulae, but specific requirements for cannula size and flow characteristics need to be developed. We evaluated the feasibility of trans-hepatic cannulation based on patient measurements and bench-top modeling. Two hundred patients admitted to the University of Michigan Pediatric CICU were evaluated. Patients over 14 years and dextrocardiac patients were excluded. The distance from the skin between the 10th and 11th ribs at the mid-axillary line to the left-heart border was measured on x-ray. LA size was measured on echocardiogram. From these measurements, prototype cannulae were fabricated. Benchtop testing of developed cannulae was performed with a pump speed of 8500 RPM and fluid viscosity of 4.0 cP at physiologic atrial and arterial pressures. Inlet pressure and deliverable flows were measured. The proposed design delivered sufficient flow with negative pressures low enough to avoid hemolysis. Trans-hepatic LA cannulation for percutaneous VAD placement is feasible. The shorter distance to the LA and larger hepatic vein size allows design of pediatric-appropriate cannulae with adequate flow rates.

Research paper thumbnail of Intraoperative and percutaneous stenting of congenital pulmonary artery and vein stenosis

Circulation, 1993

Conventional surgical or balloon dilation therapy for pulmonary artery or vein stenosis has been ... more Conventional surgical or balloon dilation therapy for pulmonary artery or vein stenosis has been unsatisfactory in many patients. Balloon-expandable stents offer a new form of treatment for these vascular stenoses and can be implanted percutaneously or intraoperatively. Between July 1991 and October 1992, 20 balloon-expandable Palmaz stents (Johnson & Johnson) were implanted in 16 children at median age and weight of 3.0 years and 12.8 kg, respectively. Stent implantation was performed intraoperatively (n = 15) if the patient was less than 1 year of age or less than 10 kg in weight, in cases where limited vascular access precluded percutaneous implantation, or as an adjunct to other intracardiac surgery. Otherwise, percutaneous stenting was performed (n = 5). Vessels were tested for distensibility by dilation with balloon catheters or vascular sounds. Stents were implanted using angioplasty catheter balloons chosen to achieve desired vessel diameter and inflated to 4 to 17 atm. Acut...

Research paper thumbnail of Central pulmonary artery growth patterns after the bidirectional Glenn procedure

The Journal of thoracic and cardiovascular surgery, 1994

The changes in pulmonary artery size and hemodynamics in 30 patients with univentricular cardiac ... more The changes in pulmonary artery size and hemodynamics in 30 patients with univentricular cardiac anatomy were examined before and after bidirectional Glenn procedures done between October 1989 and February 1992. Serial angiographic and hemodynamic examinations before and 17.6 +/- 1.6 months after bidirectional Glenn procedures were compared. At the follow-up study there was no significant change in diameter of the pulmonary artery ipsilateral to the bidirectional Glenn shunt, however, a significant decrease was noted in the diameter of the pulmonary artery contralateral to the bidirectional Glenn shunt (p = 0.04). There was also a 32% decrease in the Nakata index of total cross-sectional pulmonary artery area after the bidirectional Glenn procedure (p = 0.004). Total pulmonary blood flow and mean pulmonary artery pressure had decreased, and arterial oxygen saturation had increased at follow-up. These changes, however, did not correlate with the observed changes in pulmonary artery s...

Research paper thumbnail of Pediatric cardiology outcomes research using an intervention-specific registry: the PDA Coil Registry

The PDA Coil Registry was organized in 1994 as an open, voluntary, multicenter registry of data o... more The PDA Coil Registry was organized in 1994 as an open, voluntary, multicenter registry of data on coil occlusion of patent ductus arteriosus. In the less than two years in which new patients were recruited, over 1300 procedures were reported to the registry. To encourage participation, the registry limited the amount of data to be reported, requested only data which would be collected for clinical purposes, and separated reporting of the initial procedure from the submission of follow-up data. The PDA Coil Registry is an example of an intervention-specific registry which was able to gather substantial data for carefully focused outcomes research in a limited period of time with a modest investment of resources. 0 1997 Elsevier Science Ireland Ltd.

Research paper thumbnail of Acc/Aha/Aap Recommendations for Training in Pediatric Cardiology

PEDIATRICS, 2005

by guest on May 24, 2020 www.aappublications.org/news Downloaded from REFERENCE 1. Beller GA, Bon... more by guest on May 24, 2020 www.aappublications.org/news Downloaded from REFERENCE 1. Beller GA, Bonow RO, Fuster V. ACC revised recommendations for training in adult cardiovascular medicine Core Cardiology Training II (COCATS 2) (revision of the 1995 COCATS training statement). J Am Coll

Research paper thumbnail of Contractile Response to Sympathetic Innervation in Neonatal Ventricular Cardiomyocytes of the Spontaneously Hypertensive Rat

Pediatric Research, 1991

Differences in cardiac development between spontaneously hypertensive rats (SHR) and their normot... more Differences in cardiac development between spontaneously hypertensive rats (SHR) and their normotensive Wistar Kyoto (WKY) controls are observed before the onset of hypertension. To determine whether intrinsic differences in myocardium or autonomic neurons might be responsible for these observations, we studied primary cultures of isolated, never previously innervated ventricular cardiomyocytes from neonatal rats of both strains, and sympathetic innervation was produced by addition of neurons from thoracolumbar sympathetic ganglia. Both samestrain and cross-strain innervation were compared. Amplitude and frequency of contraction were measured from video images of spontaneously contracting cells by on-line video motion analysis. Sympathetic innervation improved contractile function by 61% in SHR cardiomyocytes ( p < 0.001), an effect qualitatively similar to that previously reported for WKY cardiomyocytes. Contractile function of SHR cardiomyocytes cultured without sympathetic explants was 25% less than that of WKY cells ( p < 0.005), but the response of SHR cardiomyocytes to sympathetic innervation was twice as great as that of WKY myocytes ( p < 0.01). Cross-strain innervation experiments showed that sympathetic neurons from both strains were equally effective; interstrain differences were confined to the cardiomyocytes. Interstrain differences in cardiomyocyte contractile function and contractile response to sympathetic innervation are present before the onset of hypertension, and may in part account for alterations in cardiac function observed in prehypertensive SHR. (Pediatr Res 30: 207-210,1991) Abbreviations SHR, spontaneously hypertensive rat WKY, Wistar Kyoto rat Several investigators have documented cardiomyocyte hyperplasia and relative cardiomegaly in newborn SHR compared with the normotensive WKY strain (1-5). Despite SHR cardiomyocyte hyperplasia, cardiac contractility is lower in neonatal SHR than in WKY (3-5), implying that contractile function at the single-cell level is considerably reduced in the SHR. Because

Research paper thumbnail of Failure of color flow mapping to identify coronary artery to pulmonary artery fistula

Pediatric Cardiology, 1991

A case of coronary artery to pulmonary artery fistula presented with the typical clinical finding... more A case of coronary artery to pulmonary artery fistula presented with the typical clinical findings of asymptomatic precordial continuous murmur and small left-to-right shunt. Echocardiography with color flow mapping failed to demonstrate the fistula on three occasions, including one study performed after angiographic demonstration of the fistula site. This case illustrates the importance of angiography in patients with unexplained continuous murmurs, even when echocardiographic and color flow mapping results are normal.

Research paper thumbnail of Total anomalous origin of the coronary arteries from the pulmonary artery

Pediatric Cardiology, 1986

The clinicopathologic features of four patients with total anomalous origin of the coronary arter... more The clinicopathologic features of four patients with total anomalous origin of the coronary arteries from the pulmonary artery (TCAPA) are presented and compared with 21 previously reported cases . Patients with TCAPA usually present with left ventricular heart failure, angina, or associated cardiovascular anomalies . Of the 19 patients in whom a clinical history was available, 16 were symptomatic before three days of age . All patients died with 60% dying before two weeks of age . Longer survival was associated with additional cardiovascular anomalies that increased pulmonary arterial perfusion pressure, oxygen saturation, or both . Seventeen (68%) patients had additional cardiovascular anomalies, most commonly atrial (nine cases) or ventricular (eight cases) septal defects and tetralogy of Fallot or other variants of pulmonary atresia (four cases) . Only five (22%) of 23 had noncardiovascular anomalies . The coronary arteries arose equally from either one ostium or from two, and the number of ostia was not related to either anomalous coronary artery distribution or to the presence of additional cardiovascular anomalies . Cardiomegaly was present in 56% of cases and the majority of patients had myocardial fibrosis or infarction . Embryology is reviewed and evidence is presented to support the theory of involution-persistence of coronary artery anlagen as the pathogenetic mechanism of TCAPA .

Research paper thumbnail of Concealed Atrial Parasystole Following the Senning Operation

Pacing and Clinical Electrophysiology, 1988

YOUNG, M.-L., ET AL.: Concealed atrial parasystole following the Senning operation. A patient wit... more YOUNG, M.-L., ET AL.: Concealed atrial parasystole following the Senning operation. A patient with sick sinus syndrome /oJiowing the Senning operation was also found to have concealed atrial parasystole during intracardiac eJectrophysioJogical study. This atriai parasystolic pattern could he converted to atriaJ bigeminy by changing the atrial drive rate. (PACE, Vol. 11, November 1988} atrial dysrhythmia. congenital heart disease, transposition of the great arteries, parasystole

Research paper thumbnail of Echocardiographic predictors for successful aortic valve replacement with pulmonary autograft (Ross) procedure in children

Journal of the American Society of Echocardiography, 1995

Journal of the American Society of Echocardiography, Volume 8, Issue 3, Pages 402, May 1995, Auth... more Journal of the American Society of Echocardiography, Volume 8, Issue 3, Pages 402, May 1995, Authors:Ohad Ludomirsky; Achi Ludomirsky; Thomas Lloyd; Gerald Serwer; Roger P. Vermilion; Ralph Mosca; Ed Bove. ...

Research paper thumbnail of 783-2 Follow-up After Coil Occlusion of Patent Ductus Arteriosus

Journal of the American College of Cardiology, 1995

Conclusions: 1) Survival analysis estimates 93% complete PDA closure after a single coil occlusio... more Conclusions: 1) Survival analysis estimates 93% complete PDA closure after a single coil occlusion procedure; 2) Residual shunts are associated with larger PDA diameter, and most close spontaneously; and 3) When necessary, a second coil occlusion has been uniformly successful.

Research paper thumbnail of Repeat balloon aortic valvuloplasty: Is it worthwhile?

Journal of the American College of Cardiology, 1996

failure to implant the coil, and by incomplete closure. We report a snareassisted technique wh~l ... more failure to implant the coil, and by incomplete closure. We report a snareassisted technique wh~l optimizes 0oil position for improved occlusion and minimizes dsk of embollzation.

Research paper thumbnail of The PDA coil registry: 250 patient-years of follow-up

Journal of the American College of Cardiology, 1996

It has been suggested that hibernation, a condition of chronic pedusinn-COntraction down-regulati... more It has been suggested that hibernation, a condition of chronic pedusinn-COntraction down-regulation with preserved viability, results from recurrent episodes of reversible ischemia and "chronic" postischemic dysfunction. We examined the interrelation between flow, metalxdism, and function in an acute model of repetitive stunning. Nine dogs underwent four 5 rain balloon occlusions of the LAD or circumflex arteries, each separated by 5 rain of reperfusion. Regional blood flow (BF), metabolism and function were evaluated 2 hourS after reperfusion in 5 dogs, and 2 hours, 24 hours, and 1 week post-reperfual0n in 4 dogs, Regional wall motion 0NM) was evaluated with 2-D echo and 8F with radiotsbalod micraspheres. Measurements of oxidative metabolism (MVO2) and glucose uptake (during hypednsulinemioeuglycemic ¢tsmp) were derived with PET imaging. Regional WM was severely decreased after the 4 Cycles of ischemia, remained severely impaired 2 hours after repertusion, and normalized after 1 week. Dudng reflow, BF in stunned regions was restored to near-normal levels (0.89 • 0,2 vs 0.95:1:0.2 ml/g/min, P < 0.01). Glucose uptake in stunned regions was depressed at 2 hours (73 • 15% of control, P < 0.001) and 24 hours after retiow (80 4-7% of ~ontrel, P = 0.04), but recovered after I week (100 • 26°/= of control, P = NS), Similarly, MVO2 in stunned regions was decreased at 2 hours (84 :E 7% of COntrol, P < 0.001 ) and at 24 hours (8~) :E 6% of COntrol, P = 0.02), and recovered 1 week after reperfusion (97 • 3% of COntrol, P = NS). Thus, repetitive stunned myocardium demonal~tod a persistent reduction of both MVO2 and glucose uptake which recovered as regional wall motion improved. The resu~ may have important implk;ations for detecting stunning in patients with CAD and further suggest a unique metabolic adaptation in "chronic stunning ~, different from that typically seen in hibemalion. ~ Tc-99m.Labeled Ap4A for Early Gamma Scintigrephlc Visualization of Experimental Athemscleroti¢ Lesions Substances related to ATP such as diadenosine tetraphosphate (Ap4A) bind to purina receptors in vascular smooth muscle o~IL Since proliferating smooth muscle cells are an obligatory COmponent of atherosolerotic lesions, T¢-99m-Ap4A was used to assess whether puflne receptors are upregutsted and can detect atherosclerottc lesions in vive.

Research paper thumbnail of Effect of intralipid on the neonatal pulmonary bed: An echographic study

The Journal of Pediatrics, 1986

The effect of !ntralipid infusion on pulmonary vascular resistance was studied prospectively by s... more The effect of !ntralipid infusion on pulmonary vascular resistance was studied prospectively by serial echocardiography on 13 occasions in six low birth weight infants. After 90 minutes of Intralipid infusion, the ratio of right ventricular preejection period to ejection time (RVPEP/ET) rose from 0.232 _+ 0.025 (mean • SD) to 0.285 _+ 0.035 (P = 0.0001). Of the 13 infusions studied, six (43%) resulted in RVPEP/ET values suggestive of pulmonary hypertension. Six LBW infants were observed over the same time period without Intralipid infusion, and RVPEP/ET did not change (0.209 • 0.035 vs 0.194 • 0.024). The increase in RVPEP/ET with Intraiipid administration could not be explained by differences in preload or contractility, and most likely reflects an increase in pulmonary vascular tone. Caution in the use of Intralipid is recommended in infants who would be at particular risk from increased pulmonary vascular resistance. (J PEDIATR 1986;I08:130-133)

Research paper thumbnail of Accuracy of central venous pressure monitoring in the intraabdominal inferior vena cava: A canine study

The Journal of Pediatrics, 1992

To test the hypotheses that in multiple pathophysiologic settings (1) end-expiratory central veno... more To test the hypotheses that in multiple pathophysiologic settings (1) end-expiratory central venous pressure measurements in the intraabdominal inferior vena cava accurately reflect those in the superior vena cava and (2) mean central venous pressure monitoring is as reliable in the inferior vena cava as it is in the superior vena cava. Simultaneous inferior vena caval and superior vena caval pressures were measured during five ventilatory phases: apnea, end-expiratory mechanical ventilation, maximal inspiratory mechanical ventilation, end-expiratory spontaneous ventilation, and maximal inspiratory spontaneous ventilation. Measurements were repeated after progressive intravascular volume depletion. Eight puppies. Simultaneous inferior vena caval and superior vena caval end-expiratory pressures did not differ significantly (mean differences 0 to 0.1 mm Hg) and the limits of agreement of these measurements were within 2 mm Hg. Differences between mean maximal inspiratory pressures in the inferior vena cava and superior vena cava during mechanical and spontaneous ventilation were -0.7 and 3.6 mm Hg, respectively (p less than 0.01), and the limits of agreement extended beyond 2 mm Hg. Furthermore, mean maximal inspiratory pressures in the superior vena cava differed from end-expiratory pressures in the superior vena cava (1.1 and -3.6 mm Hg, p less than 0.01), whereas those in the inferior vena cava did not differ from end-expiratory superior vena caval pressures. Under the experimental conditions studied (1) end-expiratory intraabdominal inferior vena caval pressures accurately reflected end-expiratory superior vena caval pressures and (2) mean central venous pressure monitoring was as reliable in the inferior vena cava as in the superior vena cava.

Research paper thumbnail of Sympathetic innervation improves the contractile performance of neonatal cardiac ventricular myocytes in culture

Journal of Molecular and Cellular Cardiology, 1990

We propose that sympathetic innervation could contribute to the improvement in cardiac contractil... more We propose that sympathetic innervation could contribute to the improvement in cardiac contractility that normally occurs during neonatal life because these processes are developmentally coincident. Effects of sympathetic innervation were studied in primary cultures of isolated, not previously innervated ventricular cardiomyocytes from neonatal rats. Innervation was produced by addition of autologous neurons from the thoracolumbar sympathetic ganglia, and amplitude and frequency of myocyte contraction were measured by on-line video motion analysis. Sympathetic innervation significantly (P less than 0.0001) increased amplitude of contraction (by 34 +/- 8%) and decreased contraction frequency (by 36 +/- 3%). The effect of innervation on myocyte contractility was not attenuated by adrenoceptor blockade (10(-6) M propranolol and 10(-6) M phentolamine), but could be reproduced using medium conditioned by cocultures of neurons and myocytes. Sympathetic innervation improves the contractility of isolated cardiomyocytes, indicating that autonomic innervation contributes to maturation of cardiac function.

Research paper thumbnail of Identification of Coronary Artery to Right Ventricular Fistulae by Color Flow Mapping

Echocardiography, 1988

Page 1. CASE REPORTS Identification of Coronary Artery to Right Ventricular Fistulae by Color Flo... more Page 1. CASE REPORTS Identification of Coronary Artery to Right Ventricular Fistulae by Color Flow Mapping THOMAS R. LLOYD, MD, LARRY T. MAHONEY, MD, WILLIAM J. MARVIN, JR., MD, and DIANA KNOEDEL, PA-C ...