Leftward displacement of septum primum in hypoplastic left heart syndrome.

Embryologic development of atrial septum primum antedates formation of the atrioventricular and semilunar valves. Leftward displacement of the superior attachment of septum primum (LDSP) has only been described in hypoplastic left heart syndrome (HLHS). This study reports the frequency of LDSP in HLHS and correlates LDSP with other echocardiographic features of HLHS. Preoperative echocardiograms for 72 consecutive patients with classic HLHS from 1996 to 2002 at Children's Hospital of Wisconsin were reviewed. One patient was excluded for inadequate imaging. Data for the 71 patients included the following: size, location, and Doppler gradient across the atrial septal defect (ASD); location of attachment of septum primum; size and patency of the aortic valve (AoV) annulus; size and patency of the mitral valve (MV) annulus; ascending aorta diameter (AAD); and left-ventricular end diastolic dimension (LVEDD). Patients were categorized into three groups: aortic atresia/mitral atresia (AA/MA), aortic atresia/mitral stenosis (AA/MS), and aortic stenosis/mitral stenosis (AS/MS). LDSP was seen in 46 of 71 patients (64 %). By diagnostic group, 32 of 35 patients with AA/MA had LDSP (91 %) compared with 10 of 19 AA/MS patients (53 %) and 4 of 17 AS/MS patients (24 %), p < 0.05. AoV patency was seen in 4 of 46 (9 %) patients with LDSP compared with 13 of 25 (52 %) patients with normal atrial attachment, p < 0.005. Mean left heart dimensions in infants with LDSP compared with normal attachment were as follows: AoV annulus 2.24 versus 3.83 mm, AAD 2.34 versus 4.1 mm, MV annulus 3.21 versus 6.48 mm, and LVEDD 6.38 versus 13.83 mm. By two-way analysis of variance of diagnostic category versus atrial septal attachment with interaction, MV annulus and AAD were independently predicted smaller by LDSP versus normal atrial attachment, p < 0.05. Nonsignificant factors included AoV annulus, LVEDD, ASD size, and Doppler gradient. LDSP correlates with more severe maldevelopment of the left heart in patients with HLHS. Because formation of septum primum precedes development and growth of the intracardiac valves, we speculate that LDSP may be an initiating event in the development of HLHS. In addition, prenatal identification of LDSP may help direct planning of potential in utero therapies.

Impact of mitral stenosis and aortic atresia on survival in hypoplastic left heart syndrome.

BACKGROUND: Aortic atresia has been implicated as a risk factor for decreased survival after stage 1 palliation. Prior studies evaluating the association of anatomic subtypes and mortality report conflicting results. Our objective was to determine if mitral valve patency with aortic atresia is associated with increased mortality in hypoplastic left heart syndrome (HLHS). METHODS: All patients (n = 72) with classic HLHS born between August 1996 and May 2002, who underwent stage I Norwood palliation, had presenting echocardiograms reviewed for patency of the mitral and aortic valves. The cohort was divided into three groups: aortic atresia-mitral atresia (AA-MA), aortic stenosis-mitral stenosis (AS-MS), and aortic atresia-mitral stenosis (AA-MS). Analysis included analysis of variance techniques for continuous variables and the 2-tailed Fisher exact test for categoric variables. Survival analysis was performed using the Kaplan-Meier method with log-rank testing. RESULTS: Of the 72 patients, 36 had AA-MA, 17 had AS-MS, and 19 had AA-MS. The stage 1 hospital survival was 92% for the entire cohort, 97% for AA-MA, 94% for AS-MS, and 79% for AA-MS (p = 0.05). Interstage mortality was 8% (6 of 72) overall, but was 21% (4 of 19) for AA-MS versus 6% (2 of 36) for AA-MA and 0% for AS/MS. Overall survival to date was 79% for the entire cohort but was 58% for AA-MS, 86% for AA/MA, and 88% for AA-MS (p = 0.015). Aortic atresia alone was not associated with increased mortality (p = 0.2). CONCLUSIONS: In patients with HLHS, aortic atresia was associated with increased mortality only in the presence of a patent mitral valve. The highest incidence of death was observed primarily during the interstage period.

Early cavopulmonary anastomosis after Norwood procedure results in excellent Fontan outcome.

BACKGROUND: Children with univentricular hearts and aortic arch obstruction are treated sequentially with Norwood procedure, superior cavopulmonary anastomosis (SCPA), and Fontan operation. Early SCPA results in lower initial O2 saturation and longer hospitalization, but not increased mortality. We sought to determine the impact of early SCPA on Fontan candidacy and outcomes. METHODS: Eighty-five consecutive patients undergoing Norwood operation between January 1998 and February 2003 were divided into group 1 (SCPA at less than 4 months, n = 33) and group 2 (SCPA at more than 4 months, n = 52). Of the original cohort, 69 have undergone Fontan operation, 7 await Fontan, 1 was transplanted, 3 are not Fontan candidates, and 5 died late after SCPA. Group 1 (n = 25) and group 2 (n = 44) patients who have completed Fontan operation were compared for preoperative and perioperative variables: age, size, O2 saturation, pulmonary artery pressure and size, prevalence of tricuspid regurgitation and ventricular dysfunction, extubation rate in operating room, duration of pleural drainage, hospital stay, and discharge O2 saturation. Late functional status and ventricular function were also compared. Survival was compared for original groups 1 and 2. RESULTS: There were no differences for any preoperative or perioperative variable, or late functional assessment. Actuarial survival at 6 years was also not different (88% +/- 5% for group 1 and 94% +/- 4% for group 2, p = 0.72). CONCLUSIONS: Although initially more cyanotic and hospitalized longer than older peers, younger SCPA patients achieve clinical equivalence by the time of Fontan operation and afterward. We conclude that both short- and long-term outcomes support performance of early SCPA.

Systemic venous oxygen saturation after the Norwood procedure and childhood neurodevelopmental outcome.

OBJECTIVE: Neonates with hypoplastic left heart syndrome have impaired systemic oxygen delivery and also have a high risk of hypoxic ischemic brain injury with resultant neurodevelopmental impairment. We hypothesized that decreased postoperative oxygen delivery, as measured on the basis of systemic venous oxyhemoglobin saturation, would be related to persistent neurodevelopmental abnormality assessed in childhood. METHODS: Early perioperative hemodynamic data, prospectively acquired from neonates undergoing staged palliation of hypoplastic left heart syndrome by using deep hypothermic circulatory arrest with uniform perioperative management, were tested for relationship to later neurodevelopmental outcome assessed at age 4 years. RESULTS: Complete hemodynamic and neurodevelopmental data were available in 13 patients aged 7 +/- 8 days at the time of the Norwood procedure and aged 4.5 +/- 0.7 years at follow-up assessment. The subjects scored significantly below the population mean for motor, visual-motor integration, and composite neurodevelopmental outcomes. The 5 (38%) patients with abnormal outcomes had significantly lower postoperative systemic venous oxygen saturation values than those with normal outcomes (46% +/- 8% vs 56% +/- 6%, P = .024). Standard hemodynamic parameters did not differentiate patient outcomes. The risk of abnormal outcome increased with increasing time at a systemic venous oxygen saturation of less than 40% (P < .001). A multivariate model of deep hypothermic circulatory arrest time, systemic venous oxygen saturation, blood pressure, and carbon dioxide tension accounted for 79% of the observed variance (P < .001). CONCLUSIONS: Decreased systemic oxygen delivery in the neonatal postoperative period is associated with hypoxic-ischemic brain injury and childhood neurodevelopmental abnormality. Measures of systemic oxygen delivery should be used to guide perioperative strategies to reduce the risk of hypoxic-ischemic brain injury.

Exercise recommendations and risk factors for sudden cardiac death.

This article reviews the risk factors that are associated with exercise that can lead to sudden cardiac death and what can be done to identify those who are at risk. Additionally, exercise recommendations to reduce the chance of sudden cardiac death and comments about restrictions and quality of life issues are addressed.

Early cavopulmonary anastomosis in very young infants after the Norwood procedure: impact on oxygenation, resource utilization, and mortality.

BACKGROUND: The optimal timing of second-stage palliation after Norwood operations remains undefined. Advantages of early cavopulmonary anastomosis are early elimination of volume load and shortening the high-risk interstage period. Potential disadvantages include severe cyanosis, prolonged pleural drainage and hospitalization, and excess mortality. We reviewed our recent experience to evaluate the safety of early cavopulmonary anastomosis. METHODS: Eighty-five consecutive patients undergoing post-Norwood operation cavopulmonary anastomosis were divided into group I (cavopulmonary anastomosis at <4 months; n = 33) and group II (cavopulmonary anastomosis at >4 months; n = 52). Groups were compared for age; size; early and late mortality; preoperative, initial postoperative, and discharge oxygen saturation; and duration of mechanical ventilation, intensive care unit stay, pleural drainage, and hospitalization. RESULTS: Group I patients were younger than group II patients (94 +/- 21 days vs 165 +/- 44 days, respectively; P <.001) and smaller (4.8 +/- 0.8 kg vs 5.8 +/- 0.9 kg; P <.001). The preoperative oxygen saturation was not different (group I, 75% +/- 10%; group II, 78% +/- 8%; P =.142). The oxygen saturation was lower immediately after surgery in group I compared with group II (75% +/- 7% vs 81% +/- 7%, respectively; P <.001) but not by discharge (group I, 79% +/- 4%; group II, 80% +/- 4%). Younger patients were ventilated longer (62 +/- 86 hours vs 19 +/- 42 hours; P =.001), in the intensive care unit longer (130 +/- 111 hours vs 104 +/- 94 hours; P =.049), hospitalized longer (12.5 +/- 11.5 days vs 10.3 +/- 14.8 days; P =.012), and required longer pleural drainage (106 +/- 45 hours vs 104 +/- 93 hours; P =.046). Hospital survival was 100% in both groups. Actuarial survival to 12 months was 96% +/- 4% for group I and 96% +/- 3% for group II. CONCLUSIONS: Early cavopulmonary anastomosis after the Norwood operation is safe. Younger patients are more cyanotic initially after surgery and have a longer duration of mechanical ventilation, pleural drainage, intensive care unit stay, and hospitalization.

Complete staged palliation of hypoplastic left heart syndrome in a child with cystic fibrosis.

In recent years, the palliative treatment of Hypoplastic Left Heart Syndrome (HLHS) with a three-staged surgical repair has gained widespread acceptance in North America and elsewhere and has significantly improved the life-expectancy of these children. We report on a child in whom the diagnosis of cystic fibrosis (CF) was made shortly after the first-stage palliation (modified Norwood procedure), and in which surgical palliation was successfully completed with second- (bidirectional Glenn) and third-stage (fenestrated Fontan) procedures. During this period, the child suffered several CF-related complications, i.e. repeated respiratory failure, meconium ileus and coagulation abnormalities, which required adjustment of the anaesthesia, surgical and intensive care management. Considering the trend to perform surgical corrections of major cardiac defects in the early neonatal period, before concomitant genetic diseases are discovered, paediatric cardiac anaesthesiologists, surgeons and intensivists may be confronted with more cases of open heart surgery in infants with CF in the future.

Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients.

BACKGROUND: Outcome of stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS) has improved coincident with application of treatment strategies including continuous superior vena cava oximetry (SvO2), phenoxybenzamine (POB), strategies to minimize the duration of deep hypothermic circulatory arrest (DHCA) and efforts to ameliorate the inflammatory response to cardiopulmonary bypass (CPB) using aprotinin and modified ultrafiltration. METHODS AND RESULTS: Analysis of a consecutive series of 115 patients undergoing S1P was done to identify the risk factors for mortality and the impact of new treatment strategies. For the current era, July 1996 to October 2001, hospital survival was 93% (75/81) compared with 53% (18/34) for the time period, January 1992 to June 1996, P<0.001. Survival to stage 2 palliation (S2P) was also significantly improved in the current era, 81% (66/81) versus 44% (15/34), P<0.01. Anti-inflammatory treatment strategies demonstrated improved survival by univariate analysis (P<0.001). Multivariate analysis identified continuous SvO2 monitoring as a factor favoring S1P survival (P=0.02) and use of POB as a factor favoring survival to S2P (P=0.003). In the current era shorter duration of DHCA was associated with improved survival to S2P (P=0.02). CONCLUSIONS: Improved survival following S1P can be achieved with strategies that allow for early identification of decreased systemic output and the use of afterload reduction to stabilize systemic vascular resistance and therefore the pulmonary to systemic flow ratio. Strategies to ameliorate the inflammatory response to CPB may decrease the degree and duration of postoperative support. Strategies to minimize duration of DHCA may improve intermediate survival and merit additional studies.