摘要:

Background Frequently the definitive operation for patients with a right ventricle (RV) that is too small to support full cardiac output is a modified Fontan operation.However, other surgical options exist that incorporate a small RV in the atriopulmonary pathway when biventricular repair is not feasible because of RV or tricuspid valve hypoplasia. The risks and benefits of these options have not been well defined.Methods and Results Between 1988 and 1993, 8 patients (6 with pulmonary atresia and intact ventricular septum and 2 with tricuspid valve stenosis and RV hypoplasia) underwent a cavopulmonary connection, which allowed right atrial blood to flow either to the pulmonary artery via the RV or directly via the cavopulmonary anastomosis.Age at surgery ranged from 1.5 to 9 years. The proximal right pulmonary artery was ligated in 5 patients, and the atrial septal defect was closed during the same procedure in 7 of the 8 patients. The echocardiographic right ventricular-left ventricular volume ratio ranged from 9% to 25%, and tricuspid valve z-scores ranged from 0 to -4. There were no deaths at a median follow-up of 24 months (range, 7 to 61 months). Mild exertional limitation was evident in only one patient. Postoperative echocardiograms demonstrated pulsatile systolic flow across the RV outflow tract in 5 patients and low-velocity diastolic-systolic flow in a sixth patient with extreme tricuspid valve hypoplasia. At postoperative cardiac catheterization (6 patients) right atrial mean pressures ranged from 7 to 13 mm Hg and mixed venous saturations from 62% to 70%.Conclusions Right atrial decompression via a superior vena cava-to-pulmonary artery anastomosis allows incorporation of a small RV into the pulmonary circulation and closure of the atrial septum, with excellent results to date. (Circulation. 1994;90(part 2):II-1-II-6.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Late postoperative arrhythmias and right ventricular dysfunction may occur after classic repair of tetralogy of Fallot.=Lown grade 2). Postoperative catheterization showed good hemodynamic results in 20 of 24 patients; 3 (12.5%) had moderate-to-severe pulmonary regurgitation, and 1 (4.2%) patient had right ventricular hypertension. Sustained ventricular tachycardia could not be induced in any of the 5 adult patients who underwent electrophysiological studies. One late death (caused by endocarditis) occurred in group B.Conclusions The right atrial approach significantly reduced the risk of life-threatening ventricular arrhythmias after repair of tetralogy of Fallot (P<.001) without increasing the incidence of supraventricular arrhythmias. Right ventricular dysfunction and severe pulmonary regurgitation were also more prevalent (P<.01) when the right ventricular approach was used. (Circulation. 1994;90(part 2):II-7-II-12.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Obstruction to left ventricular outflow can be seen after surgical repair of congenital heart disease in which a ventricular septal defect (VSD) is closed by means of a baffle to the systemic great artery arising from the right ventricle (Rastelli operation, intraventricular repair, for conotruncal anomaly).We investigated the hypothesis that obligatory volumetric changes that occur after this operation lead to acute alterations in ventricular geometry and VSD size, resulting in subsequent subaortic stenosis in patients who were thought before operation to have a large, nonrestrictive VSD orifice.Methods and Results Preoperative and postoperative echocardiograms and medical records of 24 patients with conotruncal anomaly who underwent conventional Rastelli operation or intraventricular repair in which the VSD was used as part of a new left ventricular outflow were reviewed.Eleven patients had transposition of the great arteries with pulmonic stenosis, 7 had double-outlet right ventricle, and 6 had subaortic atresia or stenosis with a normal-size left ventricle and underwent Norwood's palliation in infancy. All had large, nonrestrictive VSDs at preoperative cardiac catheterization. The mean age at the time of surgery was 32+-24 months. The following measurements were made from two- dimensional echocardiographic images obtained before and 5+-4 days after surgery from the subcostal views at end diastole: (1) VSD diameter; (2) short-axis left ventricular internal diameter (LVID); (3) left ventricular posterior wall thickness (LVPW); and (4) systemic great artery diameter (arising from the right ventricle). VSD diameter diminished significantly after surgery (11.6+-3.6 versus 10.1+-3.7 mm, P<.0001), as did LVID (34.9+-5.0 versus 31.7+-5.1 mm, P<.001). LVPW thickness increased significantly (5.7+-1.0 versus 6.7+-1.1 mm, P<.0001), while great artery diameter was unchanged (16.2+-4.0 versus 16.7+-3.8 mm, P=NS). Percent change in VSD dimension correlated with percent change in LVPW/LVIDD ratio (degree of ventricular "contraction"). Nine patients subsequently developed subaortic obstruction at the VSD orifice level and had a greater degree of early diminution in VSD size (21+-8% versus 10+-8%, P<.002) as well as postoperative change in LVPW/LVID ratio (0.24+-0.04 versus 0.20+-0.02, P<.002) than those who did not develop subsequent subaortic obstruction.Conclusions The left ventricle undergoes geometric change after Rastelli operation or intraventricular repair, surgeries in which the VSD is used as the new left ventricular outflow.These changes are manifested as increased wall thickness, decreased cavity dimensions, and a decrease in VSD size. Patients who subsequently develop left ventricular outflow obstruction have the greatest degree of ventricular contraction and VSD diminution early after surgery. (Circulation. 1994;90(part 2):II-13-II-19.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Because not much is known about the long-term results of surgical treatment of ruptured sinus of Valsalva aneurysm (RSVA), we reviewed our entire 37-year experience with this condition.Methods and Results From August 1956 through September 1993, 31 patients aged 3 to 54 years (median age, 29 years) underwent surgical correction of RSVA.Aneurysms originated in the right (n=24) and noncoronary (n=7) sinuses and entered the right ventricle in 21 patients and the right atrium in 10. Coexistent cardiac lesions included ventricular septal defect (VSD) (n=16, 15 of which were subarterial) and aortic valve insufficiency (n=13). There was a highly significant correlation between aortic insufficiency and the presence of an associated subarterial VSD (P<.0001). There was no hospital mortality. One patient (3.2%) died of endocarditis 9 years after subsequent aortic valve replacement; overall survival was 95% at 20 years. Two foreign patients were lost to follow-up after 11 and 13 years, respectively. Follow-up in the remaining 28 survivors extended to 37 years (mean, 25.7 years). Five patients (16.1%) underwent reoperation for aortic valve replacement (n=3), closure of recurrent fistula (n=1), and closure of both recurrent fistula and recurrent VSD (n=1); all had their primary operation before 1976. All patients who had reoperation had right sinus of Valsalva-to-right ventricle fistulas, and 4 had an additional subarterial VSD. Risk of reoperation was higher with right ventricle fistulas than with right atrium fistulas, and this approached statistical significance (P=.06). Risk of reoperation in patients with right ventricle fistulas was lower when an aortotomy (with or without right ventriculotomy) was used during repair (1 of 8, 12.5%) versus right ventriculotomy only (4 of 13, 30.8%), although this did not reach statistical significance (P=.10). Need for reoperation was increased with the presence of a subarterial VSD (P=.08) but not with location of fistula or type of repair (direct suture versus patch). Of 9 patients with mild aortic insufficiency at primary operation, two developed late severe aortic insufficiency necessitating aortic valve replacement at 21 and 31 years, respectively. Twenty-five patients are in New York Heart Association class I, and 3 are in class II.Conclusions Long-term survival after surgical treatment of RSVA is excellent. The risk for recurrent fistula or VSD is minimal in the current era. Late aortic insufficiency is still a risk, especially in right sinus of Valsalva-to-right ventricle fistula with associated subarterial VSD. Repair of RSVA through an aortotomy with or without cardiotomy permits inspection of the aortic root complex and facilitates aortic valve repair; this approach may reduce the incidence of late aortic insufficiency. (Circulation. 1994;90(part 2):II-20-II-29.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Primum atrial septal defect (ASD) is a defect that is usually associated with few symptoms and can be electively repaired with good results.A review of our experience with primum ASD identified a subset of patients characterized by presentation with congestive heart failure (CHF) in the first months of life and a requirement for early operation. Echocardiograms, catheterizations, operative reports, and clinical data were reviewed and compared with that on all other patients with primum ASD. Patients with transitional or complete atrioventricular (AV) canal defects were excluded.Methods and Results From January 1984 to December 1992, significant CHF was present in the first year of life in 11 patients (10.5%) with primum ASD who were managed surgically among 105 total patients undergoing repair of primum ASD. This early CHF group had a higher incidence of hypoplastic left-sided cardiac structures (9 of 11 patients) compared with other primum ASD patients (5 of 94, P<.001), including patients with coarctation (CoA) (n=9), abnormal mitral valve (n=7), left ventricular hypoplasia (n=5), and subaortic stenosis (subAS) (n=7). Other differentiators from patients without early CHF included incidence of Downs syndrome (0% versus 19%), elevated pulmonary artery pressures (72% versus 33% systemic, P<.001), earlier mean age at operation (8 months versus 5.4 years), greater incidence of reoperation after initial ASD closure (5 of 8 patients, 12 operations (5 subAS, 3 mitral valve, 3 CoA, 1 pacemaker) versus 4 of 93 patients, P<.001), and higher mortality (36% versus 1%, P<.001).Conclusions Left-sided obstructive lesions must be sought in children with primum ASD presenting with CHF in the first year of life. The presence of these lesions alters prognosis and surgical management and mandates close follow-up, with particular attention to late appearance or progression of subaortic stenosis or deterioration of mitral valve function. (Circulation. 1994;90(part 2):II-30-II-35.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Results of transcatheter implantation of the Rashkind double umbrella occluder for treatment of patent ductus arteriosus (PDA) have improved over time.We evaluated factors associated with changes in outcomes seen in the early clinical experience with this device.Methods and Results We reviewed records of otherwise healthy pediatric patients undergoing occluder implantation for isolated PDA between 1982 and 1987 at six major US and Canadian referral centers.Logistic regression was used to assess the impact of ductal size, patient age and weight, calendar time, prior intrainstitutional occluder experience, and residual center effects on closure rates. There were no study deaths. Of 180 occluder placement attempts, 76.7% (95% confidence limits=70.5%, 83.0%) produced PDA closure by auscultation at 14-month cardiology follow-up or its equivalent. Success probabilities increased in a linear fashion as ductus size decreased, ranging from 41.7% for large (4.1 to 9.0-mm) ducts to 89.4% for small (1.5 to 2.5-mm) lesions. PDA occluder closure rates also improved over time, increasing from 47.4% in 1982-1983 to 84.6% in 1986 and 83.1% in 1987. Multivariate logistic regression indicated that improved outcomes were mainly attributable to decrease in the size of treated ducts over time. Independent of this patient selection, improvements in outcome were less strongly associated with cumulative intracenter experience, calendar time, and age.Conclusions Increasing closure rates seen over time primarily reflected more judicious selection of patients as experience accumulated.However, other factors also contributed to the observed trends. An analysis of current treatment results would be of considerable interest. (Circulation. 1994;90(part 2): II-36-II-42.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Important in the postoperative management of neonates with single-ventricle complexes, such as hypoplastic left heart syndrome and pulmonary atresia with intact ventricular septum, is the fact that the pulmonary circulation is connected to the systemic circulation via a shunt. The distribution of flow to the pulmonary and systemic vascular beds depends directly on the pulmonary-to-systemic vascular resistance ratio. Changes in this ratio result in alterations in flow that have an impact on survival.Methods and Results Pico2has a potent effect on pulmonary vascular resistance.In this study, the addition of CO2to inspired gas (Pico2) is assessed as a means of modulating the ratio of pulmonary-to-systemic vascular resistance and thus flow, while avoiding the consequences of hypoventilation. Thirteen neonatal piglets (age, 17 to 30 days) were subjected to atrial septectomy, patch closure of the tricuspid valve, and creation of a 4-mm systemic-to-pulmonary arterial shunt to mimic the physiology of single-ventricle complexes. Pulmonary and systemic flows; aortic, pulmonary artery, and atrial pressures; and arterial blood gases were measured with the addition of different levels of CO2to the inspired gases (Pico2=0 to 35 mm Hg). In all animals, pulmonary vascular resistance (PVR) increased in direct correlation with Pico2. In group 1 (n=8), PVR increased in direct correlation with Pico2and Paco2, and inversely with respect to pH (r=.98,.74, and.83, respectively). Group 2 animals (n=5) received infusions of Tham to buffer hydrogen ion and compensate for respiratory acidosis. PVR again increased in direct correlation with Fico2(r=.97). In both groups, systemic vascular resistance (SVR) was less directly influenced by Fico2(r=.53).Conclusions CO2exerts a vasoactive influence on pulmonary vasculature that is largely independent of SVR and pH.Regulating Pico2is an effective means of achieving a favorable ratio of pulmonary-to-systemic vascular resistance and thus flow in the fragile physiology encountered in neonates with single-ventricle complexes. (Circulation. 1994;90(part 2):II-43-II-46.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background The main advantage of pulsatile flow compared with steady flow during cardiopulmonary bypass is to prevent a rise in systemic vascular resistances.We hypothesized that pulsatile flow could overcome the progressive rise in peripheral and placental vascular resistances observed during fetal bypass and leading to progressive irreversible hypoxemia.Methods and Results A study was undertaken in 17 fetal lambs (110 to 140 days of gestation).Fetal bypass was established for a 30-minute period through right atrial and main pulmonary artery cannulation. The circuit had no oxygenator. Flow was delivered by a standard roller pump for the continuous study (group 1, n=9) or by a centrifugal pulsatile pump for the pulsatile study (group 2, n=8). Oxymetric and hemodynamic parameters, along with organ blood flow determined by radiolabeled microspheres counting, were recorded before (T1) and after 10 minutes (T2) and 30 minutes (T3) of bypass. Sao2and Pao2were significantly higher in group 2 than in group 1 at T2 but thereafter deteriorated similarly in both groups, whereas Pco2remained unchanged. Pump flow in group 2 was significantly higher than in group 1 at T2 and T3 (957.6+-49 and 1104+-152 versus 437.6+-23 and 467.8+-43 mL/min, respectively). Systemic vascular resistances during pulsatile bypass were also significantly lower than in group 1 at T2 (402+-12 versus 930+-79 dynes/sec/cm-5) and T3 (374+-60 versus 1017+-192 dynes/sec/cm-5). At T2 and T3, all individual blood flows except the brain but including the placenta were statistically higher in group 2 than in group 1. Placental vascular resistances gradually increased during bypass in group 1 to reach 2.9+-0.2 mm Hg mL-1min-1kg-1at T3 and remained approximately stable in group 2 during 30 minutes of pulsatile bypass, varying from 0.35+-0.02 to 1.26+-0.14 from T2 to T3 (P<.01).Conclusions The data suggest that pulsatile flow for 30 minutes of bypass in a fetal lamb preparation temporarily prevents the progressive hypoxemia observed under steady-flow bypass. Pulsatile flow allows higher pump flow through a significant decrease in systemic vascular resistances. Individual organ blood flow, including placenta, was significantly higher under pulsatile bypass. With technical improvements in the design of pulsatile devices adapted to more physiological beat rates, pulsatility may become a valuable adjunct to overcome placental dysfunction observed during experimental fetal cardiac surgery. (Circulation. 1994;90(part 2):II-47-II-50.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Cardiac transplantation for children with end-stage heart disease has become an accepted form of therapy and is being practiced with increasing frequency and improving short-term outcome.Methods and Results To assess the medium-term outcome of pediatric cardiac transplantation, we analyzed our experience with 72 patients under the age of 18 (range, 0.1 to 17.7 years; mean, 9+-6.4 (SD)) who underwent orthotopic cardiac transplantation at Stanford University between 1977 and 1993. There were 38 male and 34 female patients. Preoperative diagnoses included congenital heart disease in 24 (33%), idiopathic cardiomyopathy in 27 (37%), viral cardiomyopathy in 12 (17%), and familial cardiomyopathy in 7 (10%) patients. Immunosuppressive management has evolved over time and has included a tapering schedule of steroids, azathioprine, rabbit antithymocyte globulin, cyclosporine in all patients after 1980, and induction with OKT3 since 1987. Operative mortality rate was 12.5+-4.0% (mean+-70% confidence intervals). Actuarial survival estimates at 1, 5, and 10 years are 75+-7.1%, 60+-6.4%, and 50+-8.1% (mean+-1 SEM), respectively. Causes of death included infection in 8 (28% of deaths), rejection in 7 (24%), graft coronary disease in 5 (17%), pulmonary hypertension in 4 (14%), and nonspecific graft failure in 2 (7%) patients. Survival rates were similar for patients over and those under age 10 years (including the infant cohort of 18 patients transplanted since 1986). Currently, there are 43 patients alive, all in New York Heart Association functional class I. Only 22+-5.6% of patients were free of rejection at 1 year, but 86+-5.4% were free of rejection-related death at 10 years. At 1 year, only 37+-6% of patients were free from any infection, but 88+-4.2% remained free of infection-related death at 5 years. Actuarial freedom from graft coronary artery disease (angiographic or autopsy proven) was 85+-6.6% at 5 years and from coronary artery disease-related death was 91+-4.7%.Conclusions These data demonstrate satisfactory medium-term outcome of cardiac transplantation in selected pediatric patients with end-stage heart disease, but further progress is necessary to more effectively control rejection, infection, and graft coronary disease. (Circulation. 1994;90 (part 2):II-51-II-55.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Background Accelerated coronary atherosclerosis after heart transplantation (TCAD) is a major cause of late death.It is progressive and eventually fatal, and currently no therapy exists. The purpose of this study was to determine the incidence as well as the clinical and age-dependent characteristics of pediatric patients with TCAD.Methods and Results Pediatric heart transplantation centers were surveyed on patient outcome and incidence of TCAD from August 1974 to March 1993.A follow-up questionnaire was sent to examine patient-specific details, including age at transplantation and at death, time to diagnosis, and rejection history. Data on coronary angiography and autopsy findings were requested. Replies were received from 17 US centers that performed 815 pediatric heart transplantations (including 188 neonates), with 560 survivors (69%). TCAD was identified in 58 patients (7.3%) by either coronary angiography, autopsy, or both. Detailed data were available for 45 patients. The mean age at diagnosis of TCAD was 9.9 years (0.2 to 26 years), and mean posttransplantation time was 2.2 years (0.1 to 7.7 years). TCAD occurred in 16 patients who received transplants before age 2 years. Many deaths were sudden and unexpected. Only 9 of 58 patients are alive, including 5 who had a second transplant. Four or more treated cellular rejection episodes and one or more courses of monoclonal antibody were used in 60% of patients with TCAD. Angiography was performed in 45 and was normal in 15 patients who later died of TCAD. An autopsy, performed in 36 of the 49 who died, showed severe coronary stenosis in 28 (78%) and concurrent cellular rejection in 26 (72%).Conclusions TCAD is a serious problem in transplant recipients and may affect patients of any age, even neonates.Diagnosis is difficult, and incidence of TCAD may be underestimated. TCAD appears to be associated with cellular rejection; thus, higher surveillance in patients with frequent rejection episodes is indicated. Better surveillance methods, such as intravascular ultrasound and quantitative analysis of angiographic data, are needed to improve detection and assess new treatment strategies. (Circulation. 1994;90(part 2):II-56-II-60.)

ISSN:0009-7322    

出版商:OVID    

年代:1994

数据来源: OVID