Single-Stage Surgical Management of Atrioventricular Septal Defects with Coarctation of the Aorta.

Surgical options for coarctation of aorta (CoA) with atrioventricular septal defect (AVSD) include single-stage repair vs. staged approach with neonatal CoA repair and delayed AVSD repair. The durability of left atrioventricular valve (LAVV) function after neonatal repair is questioned, and the optimal approach remains controversial. Eighteen CoA-AVSD patients who underwent single-stage repair 2005-2015 by a single surgeon were retrospectively analyzed. Fifteen patients had complete and three had partial AVSD. Birth weight was 3.19 kg (2.17-4.08). Age at surgery was 16 days (6-127). One- and ten-year survival were 80% and 69%. Freedom from reintervention was 60% and 40% at one and ten-year respectively. Reinterventions included relief of left ventricular outflow tract obstruction (LVOTO) (n = 4), repair of cleft LAVV (n = 3), and LAVV and aortic valve replacement (n = 1). Freedom from LAVV reintervention was 85.6% and 66% at 1 and 10 years respectively. There were four deaths: two post-operative and two following hospital discharge. Mortality was due to sepsis in three patients, and heart failure related to LVOTO and LAVV insufficiency in one. At 68-month (0.6-144) follow-up the majority had mild or less LAVV regurgitation, and all had normal LV dimension and systolic function. There was no recurrent arch obstruction. Single-stage surgical repair of CoA-AVSD is feasible and reasonable. Survival and freedom from reintervention in our cohort approximate those outcomes of two-stage repair with durable left AV valve function and no recurrent arch obstruction. These patients are frequently syndromic and demonstrate mortality risk from non-cardiac causes. Consideration of a single-staged approach is warranted for appropriate patients with CoA-AVSD.

Aspirin Resistance in Single-Ventricle Physiology: Aspirin Prophylaxis Is Not Adequate to Inhibit Platelets in the Immediate Postoperative Period.

BACKGROUND: Incidence of thrombosis after initial stage 1 single-ventricle palliation is high. Most centers use aspirin as an antiplatelet agent to prevent thrombosis in surgically placed shunts. We hypothesize there is a significant incidence of aspirin resistance in infants after stage 1 palliation and this resistance can be overcome by an increased aspirin dose. METHODS: This is a prospective observational study of 20 patients with single-ventricle physiology who required single-ventricle palliation with a controlled source of pulmonary blood flow (Norwood/Sano, Norwood/Blalock-Taussig [BT] shunt or BT shunt alone). Aspirin resistance was determined using thromboelastography with platelet mapping (TEG) and urine thromboxane (UTX). The UTX level of less than 1,500 pg/mL and TEG value of more than 50% were used to define as adequate platelet inhibition. The UTX was measured prior to starting aspirin (20 mg/day) and TEG and UTX were obtained after 5 days of aspirin therapy A repeat UTX was measured for patients who were determined to be aspirin resistant by TEG (<50% arachidonic acid inhibition) after doubling the dose (40 mg/day). Clinical variables including patient diagnosis, age of surgery, and cardiopulmonary bypass requirement, weight, hemoglobin, and platelet count were assessed to determine their association with aspirin resistance. RESULTS: Eighty percent of patients were aspirin resistant using TEG (95% CI, 56% to 94%) and none of the patients achieved a UTX level of less than 1,500 pg/mL. Aspirin resistant patients did not respond to an increased dose of aspirin between the fifth and tenth days of therapy (p = 0.820). Patients did, however, respond to aspirin treatment when comparing the baseline UTX measurement with those recorded on the fifth day (p = 0.008) and the tenth day (p = 0.0361) of aspirin therapy. The UTX levels did not differ between those who were and those who were not aspirin resistant by TEG at any of the measurement times. The clinical variables were not associated with aspirin resistance status. CONCLUSIONS: There is a high incidence of aspirin resistance in the immediate postoperative period after single-ventricle shunt palliation. Aspirin might not be an adequate agent for shunt prophylaxis in this patient population. Further studies are needed to identify at-risk patients who might benefit from additional testing and specific anticoagulation.

Oxygen supplementation is helpful for the echocardiographic detection of anomalous left coronary artery from the pulmonary artery.

BACKGROUND: The echocardiographic diagnosis of anomalous left coronary artery from the pulmonary artery (ALCAPA) can be challenging. The aim of this study was to assess the hypothesis that diagnosis can be enhanced by using supplemental oxygen, which decreases pulmonary vascular resistance and increases retrograde flow from the coronary artery into the pulmonary artery. METHODS: Demographic, echocardiographic, and cardiac catheterization data were reviewed in patients presenting with ALCAPA from 1999 to 2007. RESULTS: Twenty-one patients (seven male; median age, 5 months) presented with ALCAPA. Nine underwent imaging with oxygen. Two of these nine (22%) had previous standard echocardiographic studies that missed the diagnosis. Cardiac catheterization was required for diagnosis of ALCAPA in 42% of patients who underwent standard echocardiography compared with 11% of patients who received supplemental oxygen in addition to standard echocardiography. The administration of oxygen caused no significant change in heart rate or cardiorespiratory support. CONCLUSION: Transient oxygen administration is useful in the noninvasive diagnosis of ALCAPA.

Aspirin resistance in children with heart disease at risk for thromboembolism: prevalence and possible mechanisms.

Aspirin is used to prevent thromboembolism in children with heart disease without evidence supporting its efficacy. Studies in adults report a 5%-51% prevalence of aspirin resistance, yet the mechanisms involved are poorly understood. Our aims were to determine its prevalence in these children and to explore its possible mechanisms. One hundred twenty-three cardiac patients routinely receiving aspirin were prospectively enrolled. Platelet function was measured by Platelet Function Analyzer (PFA)-100 using epinephrine and adenosine diphosphate (ADP) agonists. Aspirin resistance was defined as failure to prolong the epinephrine closure time following aspirin administration. Urine levels of 11-dehydro-thromboxane B(2) (11-dTXB(2)) were measured to determine inhibition of the cyclo-oxygenase pathway. The prevalence of aspirin resistance was 26%. Median ADP closure time was shorter for aspirin-resistant (79.60-115 s) than for aspirin-sensitive (100.60-240 s) patients (p < 0.01). 11-dTXB(2) levels did not correlate with aspirin resistance. Aspirin-resistant patients had higher 11-dTXB(2) levels before (7297 vs. 4160 pg/mg creatinine; p < 0.01) and after (2153 vs. 1412 pg/mg; p = 0.03) aspirin, with a similar percentage decrease in thromboxane (70.5% vs. 66.1%; p = 0.43). Our findings suggest that resistance is not entirely due to lack of inhibition of platelet thromboxane production. Alternative sources of thromboxane and thromboxane-independent mechanisms, such as ADP-induced platelet activation, may contribute to aspirin resistance.

Left ventricular function and response to enalapril in patients with duchenne muscular dystrophy during the second decade of life.

The role of angiotensin-converting enzyme inhibitors in the management of cardiomyopathy related to Duchenne muscular dystrophy has not been completely defined. The purposes of this study were to describe the response to enalapril and its relation to dystrophin mutation type, ventricular size, or age at the onset of left ventricular (LV) systolic dysfunction. Serial clinical and echocardiographic data from 50 patients with Duchenne muscular dystrophy (aged 10 to 20 years) were retrospectively reviewed. Twenty-seven patients (46%) developed LV systolic dysfunction (mean age 13.2 +/- 2.4 years). Ten (43%) responded to enalapril with the normalization of function. Responders and nonresponders developed LV systolic dysfunction at similar ages (p = 0.91). At the onset of LV systolic dysfunction, only 2 patients (1 responder, 1 nonresponder) had dilated left ventricles. The positive response to enalapril was sustained in 7 patients (median follow-up 23 months, range 5 to 58). No specific mutation was associated with the response to enalapril (p = 0.66) or predictive of the development of LV systolic dysfunction (p = 0.8). In conclusion, 10 of 26 patients (43%) with Duchenne muscular dystrophy responded to the use of enalapril with normalization of the shortening fraction. Age at the onset of LV systolic dysfunction and the type of mutation were not predictors of response to enalapril.

Chloral hydrate sedation for pediatric echocardiography: physiologic responses, adverse events, and risk factors.

OBJECTIVE: The physiologic responses to chloral hydrate sedation in the setting of a pediatric echocardiography laboratory have not been well documented; neither has the population at risk been identified adequately. The purpose of this study was to describe the physiologic responses to chloral hydrate sedation, to report the occurrence of adverse events, and to identify any risk factors that predicted these adverse events in children who underwent sedation for echocardiography at our institution. METHODS: We analyzed retrospectively 1095 patients who were sedated for echocardiography. Vital signs and oxygen saturations were recorded every 5 minutes, and adverse events were noted. Potential risk factors for sedation-related adverse events were analyzed. RESULTS: Thirty-eight percent of patients were classified as American Society of Anesthesiologists class 3 or 4, reflecting the significant comorbidity in the study population. Hemodynamic responses to chloral hydrate sedation included > or = 20% decreases in heart rate (24% of the patients) and blood pressure (59% of the patients). There were no deaths or permanent morbidity. Adverse events occurred in 10.8% of patients and included apnea (n = 3 [0.3%]), airway obstruction (n = 15 [1.4%]), hypoxia (n = 65 [5.9%]), hypercarbia (n = 40 of 603 [6.6%]), hypotension with poor perfusion (n = 4 [0.4%]), vomiting (n = 4 [0.4%]), and prolonged sedation (n = 36 [3.3%]). No intervention was required in 92.5%, minor interventions were necessary in 7%, and major interventions were required in 0.5% of all patients. Multivariate analysis identified only age younger than 6 months as a predictor for adverse events, whereas cyanosis, hospitalization, American Society of Anesthesiologists class, fasting time, oxygen requirement, and use of additional sedation were not predictors. CONCLUSIONS: Moderate decreases in heart rate and blood pressure, in the absence of clinical deterioration, are expected responses to chloral hydrate sedation in this pediatric population. The majority of adverse events were minor, and major events were uncommon. Infants who were younger than 6 months were found to be at higher risk for serious adverse events.