Echocardiographic analysis of ventricular geometry and function during repair of congenital septal defects

BACKGROUND

This study investigated changes in left ventricular (LV) geometry and systolic function after corrective surgery for atrial (ASD) and ventricular septal defects (VSD).

METHODS

Transesophageal LV short-axis echocardiograms were recorded before and after operative repair of ASD (n = 11) and VSD (n = 7). Preload was measured using LV end-diastolic area indexed for body surface area. Measurements of septal-freewall (D1) and anterior-posterior (D2) endocardial diameters were used to assess LV symmetry from D1/D2. Systolic indices included stroke area, area ejection fraction, and fractional shortening.

RESULTS

Preload, stroke area, area ejection fraction, and fractional shortening of D1 increased after ASD repair but decreased after VSD repair (p < 0.05). End-diastolic symmetry increased after ASD closure and decreased after VSD closure (p < 0.05). Increases in stroke area and ejection fraction after ASD correction primarily reflected increased shortening of D1. A positive correlation was found overall between percent change in end-diastolic area (EDA) and percent change in area ejection fraction (r(2) = 0.80, p < 0.0001, n = 18).

CONCLUSIONS

Preload was the primary determinant of changes in LV function in this series of ASD and VSD repairs. Intraoperative changes in position of the interventricular septum affected systolic and diastolic LV symmetry and septal free wall shortening. Additional studies are needed to define changes in afterload and contractility as well as diastolic compliance and systolic mechanics.

Expression of adenylyl cyclase V/VI mRNA and protein is upregulated in cyanotic infant human myocardium

We have previously demonstrated that both basal and isoproterenol-stimulated activities of myocardial adenylyl cyclase were greater in cyanotic patients with tetralogy of Fallet (TOF) than those in acyanotic patients. However, it was not determined whether increased enzyme activity was related to a similar increase in adenylyl cyclase protein and mRNA expression. In the current study, we examined the mRNA and protein expression of cardiac adenylyl cyclase, types V and VI, in cyanotic and acyanotic patients with TOF. Ribonuclease protection assays and immunoblotting were performed on myocardial specimens obtained from cyanotic patients with TOF and acyanotic patients with TOF or ventricular septal defect. We demonstrated that in both cyanotic and acyanotic patients, there was more type V adenylyl cyclase mRNA than type VI. Types V and VI cardiac adenylyl cyclase mRNA were significantly increased in myocardium of the cyanotic group compared to the acyanotic group. Protein expression of both V and VI adenylyl cyclases was correspondingly upregulated in cyanotic patients compared to acyanotic patients. Our results indicate that gene and protein expression of cardiac adenylyl cyclases, types V and VI, is increased in the cyanotic myocardium. These results suggest that chronic hypoxemia may regulate the expression of adenylyl cyclase enzymes.

Endogenous endothelium-derived nitric oxide inhibits myocardial caspase activity: implications for treatment of end-stage heart failure

BACKGROUND

Apoptosis contributes to ventricular remodeling in heart failure (HF). Nitric oxide (NO) inhibits caspase 3, a key effector apoptotic enzyme. We hypothesized that reduced endogenous NO in HF disinhibits cardiac caspase 3 to promote apoptosis.

METHODS

Caspase 3 activity was measured colorimetrically in myocardial cell lysates from endothelial NO synthase (eNOS)-deficient mice (eNOS -/-; n = 18), cardiomyopathic (CMP) hamsters (n = 8), and explanted failing human hearts (n = 10). We stimulated myocardial caspase 3 activity by adding upstream caspase 8 or 9. Cell lysates were incubated with 10(-4) mol/liter NO donor, S-nitroso-N-acetyl penicillamine; NOS inhibitor, nitro-L-arginine-methyl ester (L-NAME); or angiotensin-converting enzyme (ACE) inhibitor, enalaprilat. Hamsters underwent echocardiography so we could study the progression of ventricular dysfunction.

RESULTS

Stimulated caspase 3 activity was lower in myocardium of eNOS +/+ compared with eNOS -/- mouse hearts (5.1 +/- 0.5 vs 7.6 +/- 1.0 pmol/10 microg/min, p < 0.05). L-NAME increased enzyme activity only in eNOS +/+ mice, indicating that endogenous NO inhibits caspase 3. Stimulated caspase 3 activity was lower in control hamsters, 3.3 +/- 0.3 pmol/10 microg/min, compared with CMP hamsters, 9.6 +/- 0.7 and 6.9 +/- 0.4 pmol/10 microg/min at 4 and 9 months, respectively. This was associated with progressive ventricular dysfunction, thinning, and dilatation. L-NAME increased enzyme activity in normal but not in CMP hamsters. In failing human myocardium, L-NAME failed to alter caspase activity, indicating reduced NO availability. Enalaprilat inhibited caspase 3, which was reversed by L-NAME. S-nitroso-N-acetyl penicillamine reversed caspase 3 activation in all groups.

CONCLUSIONS

Nitric oxide reversibly inhibits myocardial caspase 3 independent of the apoptotic signaling pathway. Reduced NO in HF increases myocardial caspase 3 activity. Agents that promote NO synthesis, including ACE inhibitors, may prevent caspase activation in HF.

Bulboventricular foramen resection: hemodynamic and electrophysiologic results

BACKGROUND

The two major surgical approaches to the relief of bulboventricular foramen (BVF) obstruction in patients with single left ventricle (LV) are the Damus-Kaye-Stansel (DKS) procedure or direct BVF resection. Theoretical advantages of the DKS include better out-flow gradient relief, lower potential incidences of postoperative heart block and lower incidences of reoperation. Potential disadvantages of this approach include increased semilunar valvar insufficiency, lack of feasibility when attempting septation-type operations for univentricular hearts, and a technically more difficult operation. We report the results of direct surgical BVF resection.

METHODS

From June 1990 to June 1999, 9 patients had direct BVF resection performed at our institution. The median age at surgery was 16.5 years (range 1 month to 27 years). Diagnoses in these patients were [S,L,L] single LV (n = 8) and [S,D,D] single LV tricuspid atresia (n = 1). Eight of 9 patients had pulmonary artery bands placed either before BVF resection or at the same time as this procedure. Three patients required reoperation for reobstruction at the BVF (12 total operations in 9 patients).

RESULTS

Median preoperative peak systolic gradient across the BVF measured at cardiac catheterization was 47 mm Hg (range 10 to 63 mm Hg). The median peak gradient measured by Doppler echocardiography was 44 mm Hg (range 5 to 125 mm Hg). Eight of 9 patients survived the operation to discharge from the hospital and 7 of 9 are alive at follow-up. At a median follow-up of 22 months (range 5 to 76 months), 8 of 8 surviving patients had an unobstructed BVF as determined by qualitative two-dimensional echocardiography and Doppler color flow imaging. There was one perioperative and one late death 5 months postoperatively (secondary to fungal sepsis). No patient developed new or worsened aortic insufficiency after BVF resection. Eight of 9 patients had no change in AV nodal conduction after surgery. One patient developed Mobitz II heart block requiring postoperative implantation of a pacemaker.

CONCLUSIONS

Direct resection of an obstructive BVF can be performed with total relief of obstruction although reoperation may be required. Atrioventricular nodal function can be preserved in most patients with this operative approach, including those with [S,L,L] segmental anatomy.

Regression of pulmonary arteriovenous malformations following heart transplantation

Pulmonary arteriovenous malformations (PAVMs) can occur following caval to pulmonary artery connection, Glenn and/or Fontan procedure, leading to severe cyanosis and exercise intolerance. It is unknown whether these abnormalities regress or persist following heart transplantation (HTx). Twenty patients with failed Fontan or Glenn procedures were screened for PAVMs prior to HTx by contrast echocardiography, selective pulmonary angiography, and pulmonary venous desaturation. Age at transplant, diagnosis, previous operations, time from Glenn to transplant, systemic oxygenation, hemoglobin level, and ventricular function were determined. The clinical course after HTx was characterized in three patients with significant PAVMs. Indications for HTx were exercise intolerance and severe cyanosis in one patient, and cyanosis and ventricular dysfunction in two. Pre-HTx, mean systemic saturation was 67%; mean pulmonary venous wedge saturation was 81%. Post-HTx, oxygen saturations were normal (> 96%) at 14, 40, and 180 days. Contrast echocardiography, performed 1 month to 3.3 yrs after HTx, showed no intrapulmonary shunting in two patients and minimal shunting in one. One patient suffered an embolic stroke from right-to-left shunting post-HTx. All patients are alive and well 35, 71, and 73 months post-HTx. In patients with single ventricle physiology, PAVMs are not an absolute contraindication to HTx. Heart-lung transplant may not be required for these patients.

Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard

Serial echocardiographic measurements of the annulus and sinus were obtained in children before the Ross operation, and early and late postoperatively. Values were compared with normal standards for the aorta and pulmonary artery (PA). There was no significant difference between PA annulus measurements before surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9 +/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ 0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p <0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ 1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be important in the assessment of autograft enlargement. Minimal change in autograft Z scores over time suggests that annulus enlargement is mainly due to somatic growth. In contrast, the autograft sinus showed an immediate and continued disproportionate increase in size over time, suggesting that sinus enlargement is largely due to passive dilation.

Hypoplastic left heart syndrome: valuing the survival

OBJECTIVE

To examine the survival, developmental status, quality of life, and direct medical costs of children with hypoplastic left heart syndrome who have undergone stage I, II, and III reconstructive surgery.

METHODS

A total of 106 children underwent staged repair for classic hypoplastic left heart syndrome between February 1990 and March 1999 (stage I: 106; stage II: 49; stage III: 25; 4 converted to heart transplantation). Survival was analyzed by the Kaplan-Meier method. In a cross-sectional study, parents assessed quality of life by completing the Infant/Toddler Child Health Questionnaire or Child Health Questionnaire Parent Format-28; they assessed developmental progress by completing the Ages and Stages Questionnaire. The ratio-of-costs-to-charges method was used to derive hospital costs, and payments were used to capture physician time and wholesale pricing for outpatient medications.

RESULTS

Institutional 1-year and 5-year actuarial survivals were 58% and 54%. Birth weight, the need for preoperative inotropic drugs, and surgical experience were predictors of survival. Norwood I patients achieved fewer developmental benchmarks than those who survived to subsequent stages. Child Health Questionnaire Parent Format-28 mean summary scores for physical and psychosocial health were 48.5 +/- 6.3 and 42.8 +/- 9.9. The median inpatient costs for stage I, II, and III repairs were $51,000, $33,892, and $52,183, respectively. Monthly outpatient and readmission costs were less than 10% of total costs.

CONCLUSION

A prospective, large-scale study of the comprehensive outcomes of staged repair and transplantation is needed. This study will need to address the longer-term developmental and quality-of-life outcomes, as well as the long-term cost effectiveness of these procedures.

Outcome after orthotopic cardiac transplantation in adults with congenital heart disease

BACKGROUND

Advances in surgical and medical management have greatly improved long-term survival rates in patients with congenital heart disease (CHD). As these patients reach adulthood, myocardial dysfunction can occur, leading to cardiac transplantation.

METHODS AND RESULTS

We reviewed the pretransplantation and posttransplantation courses of 24 patients >18 years old (mean age, 26 years; range, 18 to 56 years) with CHD who received a transplant between January 1985 and September 1998. The relation between preoperative and perioperative risk factors for complications and death was assessed. Single ventricle was the pretransplantation diagnosis for 12 patients (50%), and d-transposition of the great vessels was the diagnosis for 4 patients (16%). Twenty-two patients had a mean of 2 previous operations. At cardiac transplantation, additional surgical procedures were required to correct extracardiac lesions in 18 patients (75%). Refractory heart failure was present in 22 patients, significant cyanosis was present in 7, and protein-losing enteropathy was present in 4. There were 5 early deaths due to bleeding (n=3) and infection (n=2). The Kaplan-Meier survival rate after cardiac transplantation was 79% at 1 year and 60% at 5 years. No anatomic or surgical risk factor was predictive of death. The outcome of patients with CHD who received a transplant was compared with that for patients without CHD (n=788). Mean bypass and ischemic times were significantly longer in patients with CHD than in patients without CHD. Survival rates after transplantation did not differ significantly between patients with and those without CHD (P=0.83).

CONCLUSIONS

Successful cardiac transplantation is obtainable in adults with complex CHD, with an outcome similar to that of patients without CHD. A detailed assessment of cardiac anatomy and careful surgical planning are essential to the pretransplantation and posttransplantation management of these patients.

Tracheobronchial anomalies in children with congenital cardiac disease

OBJECTIVE

To perform preoperative airway evaluations, using radiographic analysis, to review the tracheal anatomy in children with congenital cardiac disease.

DESIGN

Prospective.

SETTING

A university children's hospital.

PARTICIPANTS

One hundred patients.

MEASUREMENTS AND MAIN RESULTS

One magnified airway film (high kilovoltage filtered) was performed preoperatively on 100 consecutive children presenting for repair of congenital cardiac disease. Events at intubation, with respect to endotracheal tube size (internal diameter in millimeters) and difficulties with placement of the tube, were recorded. Postoperative morbidity, specifically related to underlying airway anomaly, was documented. Eleven children had positive radiographic findings after review of magnified airway films. Six of 11 patients had evidence of tracheobronchial pathology, and five patients had no tracheal pathology. Difficulties with intubation were noted in two children. No perioperative morbidity was noted in any patient.

CONCLUSION

The use of preoperative magnified airway films for tracheal evaluations in children with cardiac disease should be considered.

Usefulness of preoperative echocardiography in predicting left ventricular outflow obstruction after primary repair of interrupted aortic arch with ventricular septal defect

Residual left ventricular outflow tract (LVOT) obstruction is a significant problem after repair of interrupted aortic arch (IAA) and ventricular septal defect. Resection of subaortic tissue at the time of primary repair, however, is associated with increased morbidity and mortality. We reviewed the preoperative echocardiograms and the postoperative clinical course and echocardiograms of 23 consecutive patients who underwent primary repair of IAA without widening of the subaortic region. Nine patients (39%) developed significant LVOT obstruction (pressure gradient >40 mm Hg). LVOT obstruction was noted postoperatively in 7 of 9 patients by 1 month, 8 of 9 by 2 months, and 9 of 9 by 1 year. On retrospective analysis of the preoperative echocardiograms, the indexed cross-sectional area of the LVOT, the subaortic diameter index, and the subaortic diameter Z score were all significantly smaller in those requiring reintervention (p <0.04, p <0.05, p <0.05, respectively). Of these, indexed cross-sectional area had the least reproducibility and subaortic diameter index the most (coefficient of variation of 26.3% vs 11.2%). In conclusion, most patients who develop significant LVOT obstruction after repair of IAA do so within 1 month of operation. Although subaortic indexed cross-sectional area is the most sensitive predictor of LVOT obstruction after primary repair of IAA, other more simple standardized measurements of the subaortic diameter were comparably predictive and had better reproducibility.

Double-outlet right ventricle (tetralogy of Fallot type) associated with anomalous origin of the left coronary artery from the right pulmonary artery: report of successful total repair in a 2-month-Old infant

The case reported herein demonstrates the rare association of double-outlet right ventricle (tetralogy of Fallot type) with anomalous origin of the left coronary artery from the pulmonary artery. It is the first reported successful total surgical repair in an infant.

Pediatric cardiac surgery: the effect of hospital and surgeon volume on in-hospital mortality

OBJECTIVE

To examine the relationship between annual provider (hospital and surgeon) volume of pediatric cardiac surgery and in-hospital mortality.

DESIGN

Population-based retrospective cohort study using a clinical database.

SETTING

The 16 acute care hospitals in New York with certificate of need approval to perform pediatric cardiac surgery.

PATIENTS

All children undergoing congenital heart surgery in New York from 1992 to 1995.

MAIN OUTCOME MEASURES

Risk-adjusted mortality rates for various hospital and surgeon volume ranges. Adjustments were made for severity of illness using logistic regression.

RESULTS

A total of 7169 cases were analyzed. After controlling for severity of preprocedural illness using clinical risk factors, hospitals with annual pediatric cardiac surgery volumes of fewer than 100 had significantly higher mortality rates (8.26%) than hospitals with volumes of 100 or more (5.95%), and surgeons with annual volumes of fewer than 75 had significantly higher mortality rates (8.77%) than surgeons with annual volumes of 75 or more (5.90%).

CONCLUSIONS

Both hospital volume and surgeon volume are significantly associated with in-hospital mortality, and these differences persist for both high-complexity and low-complexity pediatric cardiac procedures.

Outflow obstruction after the arterial switch operation: a multiinstitutional study. Congenital Heart Surgeons Society

OBJECTIVE

Our objectives were to discover whether outflow obstruction immutably accompanies the arterial switch operation and to identify factors that may decrease its prevalence.

METHODS

Percutaneous or surgical reintervention for obstruction after an arterial switch was selected as an end point for obstruction. Its risk factors were identified by time-related multivariable analyses of yearly follow-up data from 514 neonates with simple transposition or transposition with ventricular septal defect entering 23 institutions before 15 days of age between January 1, 1985, and March 1, 1989.

RESULTS

Sixty-two patients underwent 86 reinterventions for right-sided obstruction (83% free at 10 years) and six for left-sided obstruction (98% free at 10 years). After 2 years, right-sided obstruction occurred at a rate of about 1% per year and left-sided at a rate of about 0.1% per year. Right ventricular infundibular or valvular obstruction was associated with the aorta and pulmonary trunk positioned side-by-side, coexisting coarctation, use of prosthetic material in sinus reconstruction, one institution, and earlier institutional experience. Pulmonary trunk or pulmonary artery obstruction was associated with lower birth weight, left coronary artery arising from sinus 2, coronary explantation away from the transection site, three institutions, and earlier institutional experience.

CONCLUSIONS

A risk-adjusted base incidence (0.5% per year) of reintervention for right-sided obstruction continues late after operation. It is due in part to congenital variability or abnormality of right ventricular outflow structures and to experience and surgeon variability resulting in suboptimal pulmonary trunk reconstruction. The same sources of variability probably affect the aortic root, but its native characteristics plus higher distending pressure make the base incidence considerably less (0.1% per year).

Outcome after the single-stage, nonfenestrated Fontan procedure

BACKGROUND

A completed Fontan circulation is the goal in the management of patients with single-ventricle physiology. To achieve this end, a two-stage rather than a single-stage approach is carried out routinely at many centers. Some groups have advocated baffle fenestration for virtually all patients to minimize post-Fontan complications. Other centers perform single-stage Fontan operations and do not fenestrate. Thus controversies have arisen regarding the indications for the staged procedure versus single stage and for fenestration versus no fenestration.

METHODS AND RESULTS

The preoperative risk factors and postoperative course were characterized in 61 consecutive patients (median age, 3.3 years) undergoing a single-stage, nonfenestrated Fontan. The patients were followed for 3.5+/-1.9 years. The relationship between preoperative risk factors and mortality and morbidity was assessed. Preoperative risk factors assessed included age <2 years (n=18), branch pulmonary artery stenosis (n=20), elevated mean pulmonary artery pressure >15 mm Hg (n=16), atrioventricular valve regurgitation (n=5), and decreased ventricular function (n=2). Total caval pulmonary anastomosis was performed in 53 patients. Additional surgery was required at the time of the Fontan in 25 patients (41%). The median duration of mechanical ventilation was 1 day; median chest tube drainage was 5.5 days (range, 1 to 35). Oxygen saturation rose significantly postoperatively, from 83% to 95%. Early mortality was 4.9%; one patient died from pacemaker failure 9 months postoperatively, and one patient underwent successful heart transplant 4 months post-Fontan. One- and 5-year actuarial survival was 93%. No preoperative risk factor was associated with a failed Fontan or significant effusions.

CONCLUSIONS

A single-stage, nonfenestrated Fontan was performed in a large group of patients with excellent surgical results and intermediate outcome. There is no evidence that a two-stage approach and/or baffle fenestration is required for a large cohort of patients who are candidates for a Fontan operation.

Survival and risk factor analysis for the Norwood procedure for hypoplastic left heart syndrome

The optimal approach to hypoplastic left heart syndrome (HLHS) is controversial. The palliative Norwood operation, cardiac transplantation, and no surgical intervention have all been advocated. Centers that perform the Norwood operation have met with varied results, and conflicting reports exist regarding factors predictive of stage I outcome. From January 1990 to January 1996, 67 patients with HLHS were admitted with intent to perform the staged Norwood procedure. Fourteen patients did not undergo surgery. In the 53 patients treated surgically, outcome was reviewed, and 10 potential risk factors for first stage mortality were analyzed. Forty-one infants survived the Norwood I operation to hospital discharge (77% of the surgically treated patients and 61% of the entire group, including those who did not undergo operation) with 6 additional deaths 3 to 5 months after operation. Univariate analysis showed cardiopulmonary bypass time and circulatory arrest time to be significant risk factors for hospital mortality. Multivariate analysis revealed only cardiopulmonary bypass time as significant (p <0.01). Of the 15 prenatally diagnosed newborns who underwent surgery, 11 survived (p = 0.72). Ten of 11 patients with preoperative organ damage survived (p = 0.42). Among the 35 bidirectional Glenn (Norwood II) and Fontan (Norwood III) procedures performed, there were 2 deaths. The 5-year actuarial survival for patients who underwent operations was 61%. The Norwood procedure is a favorable option for the infant with HLHS. Surgical survival may be affected by a prolonged cardiopulmonary bypass time, but is not affected by other factors analyzed, including prenatal diagnosis and preoperative organ damage.

Right ventricular infundibular beta-adrenoceptor complex in tetralogy of Fallot patients

Patients with tetralogy of Fallot may have episodes of paroxysmal hypoxic spells ("tet spells") or could be asymptomatic. In patients who have these episodes, treatment with a beta-adrenoceptor (betaAR) blocking agent can often ameliorate or attenuate the severity of the symptoms. Additionally, excitement, crying, and situations associated with increased sympathetic activity could provoke the occurrence of these hypoxic spells. We hypothesized that altered myocardial betaAR function may contribute to the development of paroxysmal hypoxic spells in the symptomatic tetralogy patient. Surgically excised right ventricular infundibular myocardial specimens from symptomatic (patients with spells) and asymptomatic patients were used to determine total beta1 and beta2 betaAR density and betaAR adenylyl cyclase activity. Symptomatic patients had a significantly greater number of total betaAR. The relative proportion of beta1 and beta2 receptors was comparable in both patient groups. betaAR-stimulated adenylyl cyclase activity was found to be more enhanced in the symptomatic patient group. Our results indicate that infundibular betaARs may play a role in the development of paroxysmal hypoxic spells.

Plasma neuropeptide Y and catecholamines in pediatric patients undergoing cardiac operations

OBJECTIVE

Our objective was to assess the sympathoadrenal response in pediatric patients undergoing repair of congenital cardiac defects.

METHODS

Plasma catecholamine (norepinephrine and epinephrine) and neuropeptide Y concentrations were quantified before and after cardiopulmonary bypass to assess the response to cardiopulmonary bypass. To determine the response to aortic occlusion, levels of plasma catecholamines and neuropeptide Y were measured at the time of and immediately after release of the aortic crossclamp.

RESULTS

During cardiopulmonary bypass, no significant change in levels of plasma norepinephrine (n = 43), epinephrine (n = 37), or neuropeptide Y (n = 46) was observed. Aortic occlusion induced a significant increase in plasma neuropeptide Y, but not in catecholamines. There was a greater increase in plasma neuropeptide Y in children older than age 1 year than in those younger than 1 year.

CONCLUSIONS

Plasma neuropeptide Y may be a useful marker of sympathetic nervous system activity. Children younger than age 1 year showed a lesser sympathetic response compared with the response in older children.

Perioperative lymphocyte adenylyl cyclase function in the pediatric cardiac surgical patient

OBJECTIVE

To examine intraoperative and postoperative lymphocyte adenylyl cyclase activities in children undergoing repair of congenital cardiac defects with hypothermic cardiopulmonary bypass.

DESIGN

A prospective study.

SETTING

Tertiary university pediatric hospital.

PATIENTS

Twelve children were enrolled into the study to examine intraoperative lymphocyte adenylyl cyclase activities and 12 children were enrolled to examine postoperative lymphocyte adenylyl cyclase activities.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Basal (unstimulated), isoproterenol, and prostaglandin E-1 stimulated adenylyl cyclase activities, and plasma norepinephrine and epinephrine concentrations were measured. Intraoperative basal (unstimulated), beta-adrenergic receptor-stimulated (in response to isoproterenol), and prostaglandin E1 (PGE1)-stimulated lymphocyte adenylyl cyclase activities all increased during cardiopulmonary bypass, then decreased immediately after cardiopulmonary bypass. In the postoperative group, a significant decrease in basal (unstimulated), beta-adrenergic receptor- and PGE1-stimulated adenylyl cyclase activities were observed on postoperative day 1 as compared with precardiopulmonary bypass values.

CONCLUSIONS

In the pediatric cardiac surgical patient, there was an intraoperative enhancement of lymphocyte adenylyl cyclase activities. This increase in adenylyl cyclase activities was followed by reduced lymphocyte adenylyl cyclase activities, including beta-adrenergic receptor desensitization, postoperatively, as we have previously documented in adults.

Biventricular assist device as a bridge to transplantation in a pediatric patient

A 5 1/2-year-old boy with idiopathic cardiomyopathy and rapidly worsening hemodynamic parameters underwent placement of a biventricular assist device as a bridge to transplantation. Direct anastomoses to both the aorta and pulmonary artery with Dacron grafts attached to Carmeda-coated tubing facilitated the support period. Inflow was provided by right atrial appendage and left ventricular apex cannulas. A centrifugal pump provided support for 2 days until a suitable donor was identified. The technique is simple, reproducible, and effective for patients with small body surface areas.

The association of tracheal anomalies and tetralogy of Fallot

OBJECTIVE

To determine the incidence of tracheal anomalies in children with tetralogy of Fallot.

DESIGN

Retrospective.

SETTING

A university children's hospital.

PARTICIPANTS

Forty-four children with the diagnosis of tetralogy of Fallot who underwent either primary or palliative cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Three criteria were used to identify tracheal abnormalities: (1) direct laryngoscopic evidence; (2) radiographic evidence; and/or (3) inability to intubate the trachea with an endotracheal (ET) tube of appropriate size for age, followed by insertion of a 2.5-mm ET tube. An 11% incidence (5/44) of tracheal anomalies was noted. These could be separated into two categories: isolated upper airway pathology (either glottic or subglottic stenosis) and lower tracheal pathology. None of the five children identified with tracheal abnormalities manifested any preoperative signs or symptoms suggestive of airway problems. Four of the children experienced significant perioperative complications resulting directly from the underlying tracheal pathology. This represented a 9% morbidity (4/44) for patients presenting for repair of tetralogy of Fallot.

CONCLUSIONS

A significant incidence of tracheal anomalies is associated with tetralogy of Fallot, leading to potential perioperative complications.