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Biomedical subjects

J William Gaynor

Publications and source records attributed to J William Gaynor.

At least 19 recordsLinked to original sources
PubMed2006

Early results of single-stage biventricular repair of severe aortic hypoplasia or atresia with ventricular septal defect and normal left ventricle.

OBJECTIVE: Biventricular repair of aortic atresia (or severe aortic hypoplasia) is possible in the presence of a ventricular septal defect and normal left ventricle. We considered whether primary biventricular repair was a safe alternative in all cases, even in the presence of interrupted aortic arch. METHODS: This was a retrospective analysis of patients who underwent primary biventricular repair consisting of a combination Norwood-type reconstruction of the aortic arch, baffle of the left ventricle to both semilunar roots, and conduit placement from the right ventricle to pulmonary arteries. RESULTS: Between January 1995 and January 2005, a total of 21 patients underwent primary biventricular repair at a median age of 5 days and a median weight of 3.0 kg. Aortic atresia was present in 7 and aortic stenosis in 14; 6 had interrupted aortic arch. All patients with aortic stenosis had annular diameters 3 mm or smaller. Median circulatory arrest time was 55 minutes, aortic crossclamp time was 56 minutes, and total support time was 99 minutes. In-hospital survival was 100%. Postoperative echocardiography in 19 patients demonstrated no significant outflow tract obstruction. Total stay was a median of 17 days. At midterm follow-up, there has been 1 late death, and reoperation has been necessary in 10 cases. CONCLUSION: Primary biventricular repair is a safe alternative to staged repair in all cases of aortic hypoplasia with ventricular septal defect and normal left ventricle.

Aorta, Thoracic↗
PubMed2006

Heterotaxy syndrome with functional single ventricle: does prenatal diagnosis improve survival?

BACKGROUND: Despite improved outcome for many single ventricle lesions, staged reconstruction for heterotaxy syndrome with a functional single ventricle continues to have a high mortality. Prenatal identification of heterotaxy syndrome may improve long-term survival. METHODS: Our database was reviewed from January 1996 to December 2004 for patients with heterotaxy syndrome. Assessment was made for prenatal diagnosis and echocardiographic characteristics of heterotaxy syndrome. We sought to assess the accuracy of fetal echocardiography in the diagnosis of heterotaxy syndrome and determine whether prenatal diagnosis and other risk factors have an impact on survival in patients with heterotaxy syndrome. RESULTS: Of 81 patients that met criteria, 43 (53%) had prenatal diagnosis. Prenatal diagnosis had high specificity and positive predictive value for all findings but had low sensitivity for anomalous pulmonary veins. Among the 70 patients born alive, survival was 60% with median follow-up of 51.4 months (range, 6.5 to 109.7 months). Prenatal diagnosis did not improve survival (p = 0.09). None of the 11 patients with complete heart block (CHB) survived past 3 months of age. Two patients underwent heart transplantation as their first intervention and have survived. CHB and anomalous pulmonary venous connection were associated with shorter duration of survival. CONCLUSIONS: Prenatal diagnosis of heterotaxy syndrome does not improve survival in patients who undergo single ventricle reconstruction. The most potent risk factors for poor outcome (CHB, anomalous pulmonary veins) are likely not impacted by identification in utero. In light of the poor outcome, cardiac transplantation as an initial therapy may be a viable option for some patients.

Echocardiography↗
PubMed2006

Outcomes of the Fontan procedure using cardiopulmonary bypass with aortic cross-clamping.

BACKGROUND: Avoidance of cardiopulmonary bypass (CPB) and aortic cross-clamping during the Fontan procedure has been advocated to improve outcomes. We continue to use CPB with aortic cross-clamping for the Fontan procedure. METHODS: We performed a review of patients undergoing the Fontan procedure between January 1, 2000 and December 31, 2004. RESULTS: The Fontan procedure was performed in 160 patients. The median age was 2.2 years (range, 1.0 to 29.1 years). Hypoplastic left heart syndrome or a variant was present in 114 patients (71%), and heterotaxy was present in 19 (12%). CPB and modified ultrafiltration were used in all patients. Aortic cross-clamping was used in 154 (96%) of 160 patients and deep hypothermic circulatory arrest (DHCA) in 132 (83%). A lateral tunnel Fontan was performed in 69 patients (43%) and an extracardiac Fontan in 91 (57%). A fenestration was created in 144 patients (90%). Two patients died. Freedom from death or takedown was 98% (157/160). Median duration of pleural drainage was 2 days (range, 1 to 44 days) and was more than 14 days in 16 patients. Median duration of hospitalization was 6 days (range, 3 to 55 days). The small number of deaths precluded assessment of risk factors for mortality. By multivariable analysis, risk factors for pleural drainage longer than 3 days were extracardiac connection (p < 0.001) and increasing mean pulmonary artery pressure before the Fontan procedure (p = 0.033). By multivariable analysis, risk factors for hospitalization for more than 7 days were extracardiac connection (p = 0.003), increasing duration of total support (CPB and DHCA, p = 0.027), and decreasing systemic oxygen saturation before the Fontan procedure (p = 0.048). CONCLUSIONS: The Fontan procedure can be performed using CPB and aortic cross-clamping with low morbidity and mortality.

Adolescent↗
PubMed2006

Real-time 3-dimensional echocardiographic imaging of congenital heart disease using matrix-array technology: freehand real-time scanning adds instant morphologic details not well delineated by conventional 2-dimensional imaging.

OBJECTIVE: We sought to investigate whether real-time (RT) 3-dimensional echocardiography (RT3D) using matrix-array technology could resolve a specific morphologic detail that could not be well resolved during conventional 2-dimensional (2D)/Doppler echocardiographic imaging of congenital heart disease. BACKGROUND: Although 2D echocardiography is currently the primary imaging modality of congenital heart disease, there are still some anatomic details that cannot be well delineated by that modality. METHODS: In all, 70 patients underwent RT3D examination using matrix-array transducer. Applying the standard sweeping technique as for 2D imaging, freehand RT imaging was used for immediate feedback. The 2D examinations of the last 23 consecutive patients were used to validate the additional value of RT3D by 3 examiners blinded to the findings of RT3D. RESULTS: The adequacy of 2D imaging to resolve the morphologic detail in question ranged from 30% to 70%, whereas RT3D imaging was considered successful in delineating the morphologic detail in 80% to 100% of patients instantly. The image resolution was superior or equivalent to that obtained by 2D imaging. Heart valves, septal defects, and volumetric valvular and vascular color flow morphologies were well delineated by RT3D. CONCLUSION: Matrix-array RT3D is a significant breakthrough technology that allowed instant visualization of cardiac anatomic details that could not be well delineated by 2D imaging. Further improvements of some technical limitations should make RT3D matrix-array cardiac imaging a significant modality in the field of echocardiographic imaging of congenital cardiac anomalies.

Adolescent↗
PubMed2006

Illustration of the additional value of real-time 3-dimensional echocardiography to conventional transthoracic and transesophageal 2-dimensional echocardiography in imaging muscular ventricular septal defects: does this have any impact on individual patient treatment?

OBJECTIVE: We sought to answer the question of whether the additional morphologic details obtained by real-time 3-dimensional (3D) echocardiographic (RT3DE) imaging of muscular ventricular septal defect (VSD) has any significant impact on treatment options of individual patient. BACKGROUND: Muscular VSD can be safely and effectively closed by interventional catheterization procedure using VSD devices under transesophageal echocardiographic (TEE) guidance. Recent application of RT3DE has shown great promise for imaging VSD with better display of the exact geometry, size, and location of the defect. METHODS: Nineteen patients with different types of VSDs were imaged with RT3DE matrix-array transducer; there were 6 cases with muscular VSD. Based on standard transthoracic echocardiographic and TEE imaging, one patient was considered a good candidate for perventricular VSD device occlusion, three patients were considered for surgical closure, and in two patients no intervention was deemed necessary. RESULTS: RT3DE successfully displayed the exact morphology of the VSD in all 6 patients, whereas transthoracic echocardiography and TEE showed the defect as a dropout with variable diameter in different views. Such planer images did not accurately predict the exact morphology in the patient in whom device occlusion was considered and the device embolized to the left ventricle in a few heartbeats. Surgical circular patch was used in two patients and primary suture was used in two patients in agreement with the 3D morphology. In two patients the 3D morphology of the VSD was small enough that no intervention was considered. CONCLUSIONS: RT3DE imaging of muscular VSD can accurately display the exact geometry of the defect, which can have significant impact on treatment strategies of individual patients. This new imaging modality should be an important adjunct to the standard transthoracic echocardiographic and TEE imaging of these defect before any intervention.

Computer Systems↗
PubMed2006

Intracardiac temperature monitoring in infants after cardiac surgery.

BACKGROUND: Hyperthermia after cerebral ischemia is associated with worse neurologic outcome. Our goals were 3-fold: (1) to describe the postoperative temperature course in infants after cardiac surgery, (2) to compare intracardiac temperature monitoring with traditional monitoring in infants, and (3) to determine variables that influence the patients' temperatures. METHODS: Longitudinal temperature data were collected for 100 infants undergoing cardiac surgery. Intra-atrial, nasopharyngeal, esophageal, rectal, and axillary temperatures were recorded in all patients. RESULTS: The mean age at the time of operation was 128 +/- 166 days, and the mean weight was 5.1 +/- 2.4 kg. Circulatory arrest was used for 54 patients. In the operating room, the maximum intra-atrial temperature (37.5 degrees C +/- 0.6 degrees C) was significantly greater than both the simultaneous esophageal temperature (36.9 degrees C +/- 1.9 degrees C, P = .03) and nasopharyngeal temperature (36.3 degrees C +/- 2.5 degrees C, P < .001). In the cardiac intensive care unit, intra-atrial temperature was significantly greater than both axillary and rectal temperatures. During the first 24 postoperative hours, intra-atrial temperature was greater than 38 degrees C in 48 (48%) patients, rectal temperature was greater than 38 degrees C in 36 (36%) patients, and axillary temperature was greater than 38 degrees C in 7 (7%) patients. CONCLUSIONS: In patients less than 2 years of age undergoing cardiac surgery requiring cardiopulmonary bypass, intra-atrial temperature peaked 4 to 6 hours after leaving the operating room. Traditional methods of temperature monitoring significantly underestimate core temperature after cardiac surgery in infants. Use of intracardiac temperature monitoring might result in avoidance of cerebral hyperthermia.

Body Temperature↗
PubMed2006

Neurodevelopmental outcome after early repair of a ventricular septal defect with or without aortic arch obstruction.

OBJECTIVES: Cross-sectional studies of intermediate-term survivors of infant cardiac surgery have revealed a high frequency of neurodevelopmental disabilities. Few data exist regarding neurodevelopmental outcome of infants undergoing surgical intervention for a ventricular septal defect. The purpose of this study was to evaluate the neurodevelopmental outcome at 1 year of age of children who had surgical repair in infancy of a ventricular septal defect or a ventricular septal defect with aortic arch obstruction. METHODS: Children who underwent repair of a ventricular septal defect or single-stage repair of a ventricular septal defect with aortic arch obstruction at less than 6 months of age were assessed at 1 year of age by using the Bayley Scales of Infant Development II, which yields the Mental Development Index and the Psychomotor Development Index, both with an expected mean of 100 +/- 15. RESULTS: At 1 year, 55 patients (ventricular septal defect alone = 36; ventricular septal defect with aortic arch obstruction = 19) returned for evaluation. The mean Mental Development Index was 92.6 +/- 11.7, with 3 (5%) patients scoring 70 or less. The mean Psychomotor Development Index was 86.1 +/- 16.4, with 10 (18%) patients scoring 70 or less. Patients with a suspected or confirmed genetic syndrome had both a lower Mental Development Index score (P = .011) and a lower Psychomotor Development Index score (P = .001). Mental Development Index and Psychomotor Development Index were independent of anatomic (specifically aortic arch obstruction) and intraoperative factors (specifically deep hypothermic circulatory arrest). CONCLUSIONS: Neurodevelopmental outcome at 1 year of age was within the normal limits for most patients who underwent repair of a ventricular septal defect or a ventricular septal defect with aortic arch obstruction during infancy.

Aortic Arch Syndromes↗
PubMed2006

The nomenclature, definition and classification of hypoplastic left heart syndrome.

The hypoplastic left heart syndrome encompasses a spectrum of cardiac malformations that are characterized by significant underdevelopment of the components of the left heart and the aorta, including the left ventricular cavity and mass. At the severe end of the spectrum is found the combination of aortic and mitral atresia, when the left ventricle can be close to non-existent. At the mild end are the patients with hypoplasia of the aortic and mitral valves, but without intrinsic valvar stenosis or atresia, and milder degrees of left ventricular hypoplasia. Although the majority of the patients are suitable only for functionally univentricular repair, a small minority may be candidates for biventricular repair. The nature of the syndrome was a topic for discussion at the second meeting of the International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, the Nomenclature Working Group, held in Montreal, Canada, over the period January 17 through 19, 2003. Subsequent to these discussions, the Nomenclature Working Group was able to create a bidirectional crossmap between the nomenclature initially produced jointly on behalf of the European Association for Cardio-Thoracic Surgery and the Society of Thoracic Surgeons, and the alternative nomenclature developed on behalf of the Association for European Paediatric Cardiology. This process is a part of the overall efforts of the Nomenclature Working Group to create a comprehensive and all-inclusive international system of nomenclature for paediatric and congenital cardiac disease, the International Paediatric and Congenital Cardiac Code. In this review, we discuss the evolution of nomenclature and surgical treatment for the spectrum of lesions making up the hypoplastic left heart syndrome and its related malformations. We also present the crossmap of the associated terms for diagnoses and procedures, as recently completed by the Nomenclature Working Group.

Diagnosis, Differential↗
PubMed2006

Neo-aortic valvar function after the arterial switch.

OBJECTIVES: The purpose of our study was to assess the prevalence and progression, during childhood and adolescence, of dilation of the neo-aortic root, and neo-aortic valvar regurgitation, and to identify risk factors for such dilation and regurgitation, after the arterial switch operation. METHODS: We included all patients who had undergone an arterial switch operation at The Children's Hospital of Philadelphia, and had been followed for a minimum of 4 years, and had at least 2 postoperative echocardiograms. Neo-aortic valvar regurgitation was quantitatively assessed, and measurements were made of the neo-aortic root at the level of the basal attachment of the leaflets, mid-sinusal level, and the sinutubular junction. RESULTS: We found 82 patients who satisfied the criterions for inclusion, of whom 52 patients had transposition with an intact ventricular septum, and 30 had either an associated ventricular septal defect or double outlet right ventricle. The median follow-up time was 8.8 years (4.1 to 16.4 years). The neo-aortic valve had been replaced in 1 patient. Of the patients, 3 had moderate, 66 had trivial to mild, and 12 had no neo-aortic valvar regurgitation at their most recent follow-up. The regurgitation had progressed by at least 1 grade in 38 of the 82 patients (46.4%). Neo-aortic dilation was noted at the basal attachment of the leaflets, and at mid-sinusal level, which was out of proportion to somatic growth. CONCLUSIONS: At mid-term follow-up, significant neo-aortic valve regurgitation is present in 3.7%, and trivial to mild regurgitation in 81.4% of patients. The regurgitation progressed in almost half of the patients over time. We also noted progressive dilation of the neo-aortic root out of proportion to somatic growth.

Aortic Valve Insufficiency↗
PubMed2006

Management of sinus venosus defects.

Sinus venosus defects are not atrial septal defects, but are intra-atrial communications outside of the boundaries of the atrial septum. The superior type is located above and separate from the fossal ovalis, usually adjacent to the superior vena cava and the right upper pulmonary vein. The inferior type is located near the orifice of the inferior vena cava and the right lower pulmonary vein. The goal of surgical repair is closure of the defect with unobstructed drainage of the pulmonary veins to the left atrium and of the vena cava to the right atrium. Numerous techniques have been described, particularly for the repair of the superior vena cava type of defect. Mortality and morbidity should be minimal. The risk of either vena cava or pulmonary vein obstruction is low. Sinus node dysfunction can occur postoperatively, particularly when an incision has been made across the superior vena cava/right atrial junction. There is little long-term data on the functional outcomes following repair of these defects.

Cardiac Surgical Procedures↗
PubMed2006

Heart rate variability following neonatal heart surgery for complex congenital heart disease.

BACKGROUND: Altered cardiac autonomic control may play a role in the morbidity and mortality suffered by neonates who undergo surgery for complex congenital heart disease (CHD). The purpose of this study was to evaluate cardiac autonomic activity, as measured by spectral indices of heart rate variability (HRV), prior to and early after infant surgery for CHD and attempt to correlate HRV indices with clinical outcome. In addition, we assessed the hypothesis that single-ventricle physiology and surgical interruption of the great arteries negatively affects HRV. METHODS: Sixty neonates prospectively wore 24-hour Holter monitors at three time points: before and early after CHD surgery, and at 3- to 6-month follow-up. Standard spectral indices of HRV were measured. RESULTS: In the early postoperative time point, patients with single-ventricle physiology had lower low-frequency power (LF) compared to patients with two ventricles (P=0.040). Surgical interruption of the great arteries did not affect HRV in this cohort. For the entire cohort, LF (P=0.004) and high-frequency power (HF) (P<0.001) increased over the three time points, while LF/HF (P=0.119) did not significantly change. In the multivariable linear regression model, significant predictors of longer postoperative hospital stay included longer total support time (P=or<0.001), longer duration of inotrope support (P=0.012), elevated mean heart rate at postoperative time point (P=0.002), and lower LF/HF ratio at the postoperative time point (P=0.014). CONCLUSION: Patients with single-ventricle physiology have a significant physiologic reduction in LF in the early postoperative period compared to patients with two ventricles. Diminished cardiac autonomic control is associated with longer hospitalization following neonatal cardiac surgery.

Arrhythmias, Cardiac↗
PubMed2006

Population pharmacokinetics of milrinone in neonates with hypoplastic left heart syndrome undergoing stage I reconstruction.

We performed a blinded, randomized pharmacokinetic study of milrinone in 16 neonates with hypoplastic left heart undergoing stage I reconstruction to determine the impact of cardiopulmonary bypass and modified ultrafiltration on drug disposition and to define the drug exposure during a continuous IV infusion of drug postoperatively. Neonates received an initial dose of either a 100 or 250 microg/kg of milrinone into the cardiopulmonary bypass circuit at the start of rewarming. Postoperatively, milrinone was infused to clinical needs. A mixed-effect modeling approach was used to characterize milrinone pharmacokinetics during cardiopulmonary bypass, modified ultrafiltration, and postoperatively using the NONMEM algorithm. All patients in this study demonstrated a modified ultrafiltration concentrating effect that occurred despite a modified ultrafiltration drug clearance of 3.3 mL x kg(-1) x min(-1). The infants in this study demonstrated an impaired renal clearance during the immediate postoperative period. A constant infusion of 0.5 microg x kg(-1) x min(-1) resulted in drug accumulation during the initial 12 h of drug administration. Postoperatively, milrinone clearance was significantly impaired (0.4 mL x kg(-1) x min(-1)), improved by the 12th postoperative hour, and approached steady-state clearance (2.6 mL x kg(-1) x min(-1)) by postoperative day 4. In the postoperative setting of markedly impaired renal function, an infusion rate of 0.2 microg x kg(-1) x min(-1) should be considered.

Cardiopulmonary Bypass↗
PubMed2005

The relationship of postoperative electrographic seizures to neurodevelopmental outcome at 1 year of age after neonatal and infant cardiac surgery.

OBJECTIVE: The occurrence of a seizure after the arterial switch operation is associated with a worse long-term neurodevelopmental outcome. The significance of seizures after neonatal and infant repair of other congenital heart defects is not known. METHODS: A recent study at our institution demonstrated seizures documented by 48-hour electroencephalographic monitoring in 20 (11%) of 178 neonates and infants after surgery for complex congenital heart defects, including hypoplastic left heart syndrome or variants. The developmental outcomes of this cohort were evaluated at 1 year of age by using the Bayley Scales of Infant Development II, which yields 2 scores: the Mental Developmental Index and the Psychomotor Developmental Index. RESULTS: Developmental evaluations were performed in 114 (70%) of 164 survivors, including 36 with hypoplastic left heart syndrome. Postoperative electroencephalographic seizures had occurred in 15 (13%) of 114 of the entire group and in 8 (22%) of 36 of those with hypoplastic left heart syndrome. For the entire cohort, the Mental Developmental Index was 92.3 +/- 13.5, and the Psychomotor Developmental Index was 79.9 +/- 18.8 for patients without seizures, compared with 90.3 +/- 10.7 and 74.4 +/- 19.3 for those with seizures (both P > .5). For the hypoplastic left heart syndrome subgroup, the Mental Developmental Index was 92.3 +/- 14.9, and the Psychomotor Developmental Index was 74.8 +/- 19.3 for patients with seizures, compared with 91.9 +/- 12.4 and 73.9 +/- 18.3 for those without seizures (both P > .5). A frontal onset of seizures was predictive of a lower score on the Psychomotor Developmental Index, but not on the Mental Developmental Index. CONCLUSIONS: The occurrence of a seizure after cardiac operation is a marker of central nervous system injury. However, in this cohort of neonates and infants with complex congenital heart defects, the occurrence of a seizure was not predictive of a worse developmental outcome at 1 year of age as assessed by the Bayley Scales of Infant Development II.

Cardiac Surgical Procedures↗
PubMed2005

Intermediate outcomes after the Fontan procedure in the current era.

OBJECTIVE: This study was undertaken to investigate the intermediate outcomes after the Fontan operation in the current era. METHODS: A cross-sectional analysis was performed by using data gathered between October 13, 2003, and February 22, 2005, on all 310 survivors of the Fontan procedure between January 1, 1992, and December 31, 1999. Medical records were reviewed, and a customized questionnaire was administered to caregivers. Outcome variables included failure of the Fontan operation (ie, death, takedown of Fontan, or transplantation), number of cardiac-related rehospitalizations, parental assessment of health, school performance, and cardiac functional status. RESULTS: A total of 332 patients underwent the Fontan procedure during the study period. A lateral tunnel was constructed in 281 (85%), and an extracardiac Fontan procedure was performed in 51 (15%). A total of 210 (63%) children had undergone previous stage I reconstruction, and 162 (49%) had received an initial diagnosis of hypoplastic left heart syndrome. There were 310 hospital survivors of the Fontan procedure (93.4%), with an additional 16 deaths (5.2%) during follow-up and 1 living heart transplant patient before the cross-sectional period. For initial hospital survivors, Kaplan-Meier estimates of freedom from death or transplantation were 98.0% (95% confidence interval, 95.6%-99.1%) at 1 year after the Fontan procedure, 94.9% (91.6%-97.0%) at 5 years, and 93.9% (90.1%-96.2%) at 8 years. Questionnaires were completed for 240 (81.9%) of the 293 available patients. By parental recollection, a total of 130 (54.2%) children required cardiac-related rehospitalization at some point during the follow-up period. At a median follow-up of 8.6 years (range, 4.1-12.8 years), 94.6% of guardians described their child's overall health as excellent or good, and 5.4%, as fair or poor. School performance was described as above average in 30.2%, average in 39.9%, and below average in 29.8%. With regard to cardiac functional status, 34.2% responded that their child had no limitations to physical activity, 52.5% reported a slight limitation, 12.1% reported a significant limitation, and 1.2% reported a severe limitation. CONCLUSIONS: Acceptable survival outcomes have been observed at intermediate follow-up of the Fontan operation in this cohort; a significant proportion of patients had hypoplastic left heart syndrome. Although cardiac-related rehospitalization is common, the parents and guardians believed that overall health, school performance, and cardiac functional status were good to excellent for most patients.

Child↗