Surgery For Congenital Cardiac Disease Research Articles

Chylothorax after Surgery for Congenital Cardiac Disease: A Prevention and Management Protocol.

BackgroundChylothorax after congenital heart surgery is not an uncommon complication, and it is associated with significant morbidity. However, consensus treatment guidelines are lacking. To improve the treatment outcomes of patients with postoperative chylothorax, we implemented a standardized management protocol at Severance Hospital in September 2014.MethodsA retrospective review of patients treated at a single center was done. All corrective and palliative operations for congenital heart disease performed at our institution between January 2008 and April 2018 were reviewed. The incidence and treatment outcomes of postoperative chylothorax were analyzed.ResultsThe incidence of chylothorax was 1.9%. Sixty-one percent of the patients could be managed with a low-fat diet, while 28% of the patients required complete restriction of enteral feeding. Thoracic duct embolization was performed in 2 patients and chest tube drainage decreased immediately after the procedure. No patient required thoracic duct ligation or pleurodesis. After implementation of the institutional management protocol, the number of chest tube drainage days decreased (median, 24 vs. 14 days; p=0.45).ConclusionImplementing a strategy to reduce postoperative chylothorax resulted in an acceptable incidence of postoperative chylothorax. Instituting a clinical practice protocol helped to curtail the treatment duration and to decrease the requirement for surgical treatment. Image-guided embolization of the thoracic duct is an effective treatment for postoperative chylothorax.

Dexmedetomidine Exerted Anti-arrhythmic Effects in Rat With Ischemic Cardiomyopathy via Upregulation of Connexin 43 and Reduction of Fibrosis and Inflammation.

BackgroundPersistent myocardial ischemia post-myocardial infarction can lead to fatal ventricular arrhythmias such as ventricular tachycardia and fibrillation, both of which carry high mortality rates. Dexmedetomidine (Dex) is a highly selective α2-agonist used in surgery for congenital cardiac disease because of its antiarrhythmic properties. Dex has previously been reported to prevent or terminate various arrhythmias. The purpose of the present study was to determine the anti-arrhythmic properties of Dex in the context of ischemic cardiomyopathy (ICM) after myocardial infarction.Methods and ResultsWe randomly allocated 48 rats with ICM, created by persistent ligation of the left anterior descending artery for 4 weeks, into six groups: Sham (n = 8), Sham + BML (n = 8), ICM (n = 8), ICM + BML (n = 8), ICM + Dex (n = 8), and ICM + Dex + BML (n = 8). Treatments started after ICM was confirmed (the day after echocardiographic measurement) and continued for 4 weeks (inject intraperitoneally, daily). Dex inhibited the generation of collagens, cytokines, and other inflammatory mediators in rats with ICM via the suppression of NF-κB activation and increased the distribution of connexin 43 (Cx43) via phosphorylation of adenosine 5′-monophosphate-activated protein kinase (AMPK). Dex reduced the occurrence of spontaneous ventricular arrhythmias (ventricular premature beat or ventricular tachycardia), decreased the inducibility quotient of ventricular arrhythmias induced by PES, and partly improved cardiac contraction. The AMPK antagonist BML-275 dihydrochloride (BML) partly weakened the cardioprotective effect of Dex.ConclusionDex conferred anti-arrhythmic effects in the context of ICM via upregulation of Cx43 and suppression of inflammation and fibrosis. The anti-arrhythmic and anti-inflammatory properties of Dex may be mediated by phosphorylation of AMPK and subsequent suppression of NF-κB activation.

Multicenter investigation of extracorporeal membrane oxygenation application in pediatric intensive care unit in China

Objective: To survey the conduction and evaluate the effectiveness of extracorporeal membrane oxygenation (ECMO) therapy in pediatric intensive care unit (PICU) in China mainland. Methods: In a questionnaire-based survey, we retrospectively reviewed the application of ECMO in children's hospital and general hospital in China mainland to summarize and analyze the categories of diseases and prognosis of children treated with ECMO therapy. Results: By December 31, 2017, a total of 23 hospitals using ECMO, including 22 tertiary referral hospitals and 1 secondary hospital, among which 16 were children's hospitals and 7 were general hospitals. Thirty-seven ECMO equipment was available. A total of 518 patients treated with ECMO, within whom 323 (62.4%) successfully weaned from ECMO and 262 (50.6%) survived to discharge. Among 375 pediatric patients, 233 (62.1%) were successfully weaned from ECMO and 186 (49.6%) survived to discharge. Among 143 newborn patients, 90 (62.9%) successfully weaned from ECMO, 76 (53.1%) survived to discharge. ECMO was applied in veno-arterial (VA) mode to 501 (96.7%) patients, veno-venous (VV) mode to 14 (2.7%) patients, and VV-VA conversion mode to 3 (0.6%) patients. Sixty-nine patients required extracorporeal cardiopulmonary resuscitation (ECPR), including 20 newborn patients (29.0%) and 38 pediatric patients (71.0%), who were all with cardiovascular disease. Neonatal respiratory distress syndrome (26/61), persistent pulmonary hypertension of the newborn (PPHN) (12/61), and meconium aspiration syndrome (MAS) (11/61) are the most common pulmonary diseases in newborn patients; among whom, infants with PPHN had highest survival rate (10/12), followed by MAS (9/11). Among newborn patients with cardiovascular diseases, those who admitted were after surgery for congenital cardiac disease were the most common (54/82), while those with septic shock had the highest survival rate (2/3). In pediatric pulmonary diseases, acute respiratory distress syndrome was the most common (42/93), while plastic bronchitis was with the highest survival rate (4/4), followed by viral pneumonia (13/16). Among pediatric cardiovascular diseases, congenital cardiac defect was the most common (124/282), while fulminant myocarditis had the highest survival rate (54/77). Conclusion: The application of ECMO as a rescue therapy for children with severe cardiopulmonary failure has dramatically developed in China mainland.

Pediyatrik Kalp Cerrahisinde Transkutanöz ve İntraarteriyel Kan Gazı Monitörizasyonun Karşılaştırılması

Objective: We compared transcutaneous and intra-arterial blood gas measurements following pediatric cardiac surgery in this study. Material and Methods: A total of 150 pediatric patients who underwent surgery for congenital cardiac disease between June 2014 and November 2015 were included in the study. The efficacy of a transcutaneous non-invasive device in measuring oxygen and carbon dioxide pressures was evaluated in pediatric patients who underwent cardiovascular surgery for congenital diseases. Simultaneous transcutaneous and conventional arterial blood gases, as well as partial oxygen and carbon dioxide pressure levels were measured in 150 pediatric patients. Results: The mean age and weight of the patients were 3.7±3.1 years (range, 1 month to 16 years) and 11.7±15.1 kg (range 3.5 to 55 kg), respectively. The differences in the mean partial oxygen and carbon dioxide pressure levels were 8 mmHg (range, 3 to 20 mmHg) and 12 mmHg (range, 7 to 25 mmHg), respectively (p 0.05). This was due to the fact that transcutaneous measurements dependent on skin perfusion yielded more accurate and reliable results in optimal conditions, such as a relatively normal cardiovascular function. Conclusion: Although transcutaneous measurements were less accurate than the invasive method in the present study, its use in intensive care units where optimal conditions are provided could decrease the number of invasive arterial interventions and contact with blood, while also allowing continuous monitoring and the evaluation of ventilation efficacy.

The Impact of Gestational Age on Resource Utilization After Open Heart Surgery for Congenital Cardiac Disease From Birth to 1 Year of Age

The impact of gestational age on perioperative morbidity was examined using a novel construct, the resource utilization index (RUI). The medical records of subjects from birth to 1year of age entered into a pediatric cardiothoracic surgery database from a major academic medical center between 2007 and 2011 were reviewed. The hypothesis tested was that infants born at 37-38weeks (early-term infants) experience greater resource utilization after open heart surgery than those born at 39 completed weeks and that this association can be observed until 1year of age. The results support the premise that resource utilization increases linearly with declining gestational age among infants at 0-12months who undergo cardiac surgery. Five of the six variables comprising the RUI showed statistically significant linear associations with gestational age in the predicted direction. Multivariate linear regression analysis showed that gestational age was a significant predictor of an increased RUI composite. Further investigation is needed to test the concept and to expand on these findings.

Early elevation of cardiac troponin I is predictive of short-term outcome in neonates and infants with coronary anomalies or reduced ventricular mass undergoing cardiac surgery

The present study aimed to assess the usefulness of routine monitoring of cardiac troponin I concentrations within 24 hours of surgery (cTn-I<24h) in neonates and infants undergoing cardiac surgery. The added predictive ability of a high peak cTn-I<24h (within the upper quintile per procedure) for a composite outcome, including 30-day mortality and severe morbidity, was assessed retrospectively. The predicted risk for the composite outcome was estimated from a logistic regression model including preoperative and intraoperative variables. Adding a high peak cTn-I<24h to the risk model resulted in reclassification of the predicted risk. It also allowed quantification of the improvement in reclassification and discrimination by the difference between c-indexes, the Net Reclassification and the Integrated Discrimination Indexes (NRI and IDI). Overall, 1023 consecutive patients were included. Adding a high peak cTn-I<24h to the model resulted in no improvement in reclassification or discrimination in the overall population (difference between c-indexes: 0.011 [-0.004 to 0.029], NRI=0.06, P=.22, IDI=0.02, P=.06), except in a subgroup of patients undergoing the arterial switch operation with or without ventricular septal defect closure and/or aortic arc repair, anomalous origin of the left coronary artery from the pulmonary artery repair, truncus arteriosus repair, Norwood procedure, and Sano modification, in whom NRI=0.23 (P=.005) and IDI=0.05 (P<.001). Patients with coronary anomalies and patients with reduced ventricular mass should benefit from the routine monitoring of cTn-I concentrations after surgery for congenital cardiac disease.

Symmetrical Peripheral Gangrene in Four Pediatric Cardiac Surgery Patients Receiving Extracorporeal Membrane Oxygenation

Symmetrical peripheral gangrene (multilimb ischemia without large artery occlusion) is a rare condition usually associated with disseminated intravascular coagulation, hemodynamic compromise, and/or sepsis. However, it has not been described in patients on extracorporal membrane oxygenation (ECMO). Over a 5 year period, four pediatric patients developed symmetrical peripheral gangrene on ECMO after cardiac surgery. They subsequently died and came to autopsy. History, physical examination, and laboratory studies were examined. Gross and microscopic autopsy material was reviewed. Patients were 11 days to 13 years old. Extracorporal membrane oxygenation duration was 11-22 days, and limb ischemia began 2-4 days before death. Three patients had rapid onset, with ischemia developing in <48 hours. In the fourth, ischemic changes began as focal lesions and gradually spread. Two patients were septic. Three had evidence of other end-organ damage. Pressors were used in 3 patients before the limb ischemia. Autopsies disclosed ischemic changes involving all limbs, with confluent ecchymoses. In a detailed examination in 1 case, large arteries of the extremities were patent. Involved skin and soft tissue showed bland fibrin thrombi in the microcirculation, with tissue necrosis and hemorrhage. This report describes the first 4 cases of symmetrical peripheral gangrene complicating ECMO. The 4 pediatric patients all had recent surgery for congenital cardiac disease, and all had significant exposure to ECMO prior to developing limb ischemia. Symmetrical peripheral gangrene is an unusual complication of ECMO that may arise in the setting of disseminated intravascular coagulation, sepsis, or other hemostatic and/or hemodynamic imbalance.

Morbidity and mortality after surgery for congenital cardiac disease in the infant born with low weight

Low weight at birth is a risk factor for increased mortality in infants undergoing surgery for congenitally malformed hearts. There has been a trend towards performing surgery in patients early, and for amenable lesions, in a single stage rather than following initial palliative procedures. Our goal was to report on the current incidences of morbidities and mortality in infants born with low weight and undergoing surgery for congenital cardiac disease. We made a retrospective review of the data from patients meeting our criterions for entry from July, 2000, through July, 2004. The criterions for inclusion were weight at birth less than or equal to 2500 grams, and congenital cardiac malformations requiring surgery during the initial hospitalization. A criterion for exclusion was isolated persistent patency of the arterial duct. We assessed preoperative, intraoperative, and postoperative variables. We found a total of 105 patients meeting the criterions for inclusion. The median weight at birth was 2130 grams, and median gestational age was 36 weeks. The most common morbidity identified was infections of the blood stream. Infections, and chronic lung disease, were associated with increased length of stay. Survival overall was 76%. Patients with hypoplastic left heart syndrome, or a variant thereof, had the lowest survival, of 62%. The needs for cardiopulmonary resuscitation, or extracorporeal membrane oxygenation, post-operatively were the only factors identified as independent risk factors for mortality. Patients undergoing surgery during infancy for congenital cardiac disease who are born with low weight have a higher mortality and morbidity than those born with normal weight.

Early postoperative care of patients with pulmonary hypertension associated with congenital cardiac disease

pulmonary vascular bed plays a pivotal role inthe presentation and outcome of the childwith congenital cardiovascular disease. It is in theimmediate postoperative period that the child ismost vulnerable to a sudden or sustained increase inpulmonary vascular resistance. Following surgeryfor congenital cardiac disease, pulmonary vascularreactivity is heightened, and vasospastic stimulusesmay result in sudden increases in pulmonary arterialpressure and resistance, resulting in acute right-sided cardiac failure, tricuspid regurgitation, sys-temic hypotension, myocardial ischaemia, andincreased resistance in the airways. These episodes,called pulmonary hypertensive crises, may be lethalevents. Mildly stimulating events can precipitatesimilar crises, and the crises tend to last longer andcluster.

Effects of hypertonic-hyperoncotic solution on cardiac function and extravascular lung water in children after open-heart surgery

Objectives To evaluate the effects of hypertonic-hyperoncotic solution (HHS) on cardiac function and extravascular lung water in children after open-heart surgery for congenital cardiac disease. Methods 50 children with congenital cardiac disease were randomly assigned to 2 groups. The HHS group received HHS (7.5% sodium chloride with 6% hydroxyethyl-stareh 200 kDa). The ISS group received isotonic saline solution (ISS 0.9% sodium chloride). Cardiac index (CI), extravascular lung water index (ELWI), stroke volume index (SVI), mean arterial pressure (MAP), and systemic vascular resistance index (SVRI) were measured. Immediately after sur-gery, patients were loaded either with HHS or with ISS (4 ml/kg). Sodium concentration, osmolality, thrombocyte count(TC), fibrinogen, and arterial blood gases were detected before operation, immediately after loading, 15 minutes, 1,4, 12, and 24 hours after the end of vol-ume loading. Hemodynamic parameters were recorded at the same time. The total amount of dobutamine required was documented. Results In HHS group, MAP, SVI and CI increased, and SVRI decreased significantly after the administration of HHS, compared with ISS group and before administration(P<0.01 or 0.05). Both CVP and HR were unchanged in both groups. In HHS group, ELWI decreased signifi-cantly, compared with before volume administration. But ELWI increased directly and remained elevated for 60 minutes after the administra-tion of ISS. Sodium concentration increased immediately after infusion of HHS. The postoperative need for infused dobutamine in the patients in HHS group was decreased, compared with ISS group (P<0.05). All patients left the hospital in a clinically sufficient state. Condu-sions A single infusion of HHS after cardiac surgery is safe. After cardiopuimonary bypass surgery, the administration of HHS increased CI by elevating SVI in combination with a decreased SVRI. ELWI significantly decreased, which suggest that HHS effectively counteracts, the capillary leakage. Key words: Hypertonic solutions/TU; Cardiac surgical procedures; Extravascular lung water; Heart/PH

Proteomics of cerebral injury in a neonatal model of cardiopulmonary bypass with deep hypothermic circulatory arrest

Concern over neurologic injury limits safe duration of deep hypothermic circulatory arrest (DHCA) in surgery for congenital cardiac disease. Proteomics is a novel and powerful technique to study global protein changes in a given protein system. Using a neonatal model of cardiopulmonary bypass with DHCA, we sought to characterize the protein changes associated with DHCA brain injury. Ten neonatal piglets were randomized to cardiopulmonary bypass with DHCA or sham operation. DHCA animals underwent induction of bypass (100 mL x kg(-1) x min(-1)), cooling to 18 degrees C, then DHCA for 60 minutes. Animals were rewarmed to normothermia, weaned from bypass, and harvested after 30 minutes off bypass. Sham animals underwent sternotomy without further instrumentation. Plasma samples were taken before bypass and before harvest. Proteins differentially expressed in the cerebral neocortex between the 2 groups were determined by 2-dimensional differential gel electrophoresis using fluorescent cyanine dyes and mass spectrometry. A second group of 4 piglets were similarly randomized and, after the experiment, tissues underwent perfusion-fixation for histologic examination. Cardiopulmonary bypass with DHCA caused extensive histologic and ultrastructural cerebral injury. Proteomic analysis of cerebral cortex found 10 protein spots to be differentially expressed; 9 were identified by mass spectrometry to represent 6 proteins, including apolipoprotein A-1, neurofilament-M protein, and enolase. Decreased expression of plasma apolipoprotein A-1 was found in DHCA. The acute protein changes associated with cerebral injury in a neonatal model of cardiopulmonary bypass with DHCA have been characterized. These may direct further research aimed at attenuating injury seen from cardiopulmonary bypass with DHCA.

Factors determining access to surgery for children with congenital cardiac disease in Guatemala, Central America

Surgical intervention for children with congenital cardiac disease in the developing world often occurs late. Our objective was to identify factors that placed Guatemalan children at risk for delayed care. We investigated the medical and socioeconomic background of 178 children under the age of 18 years who received their first corrective surgery for congenital cardiac disease at the Unidad de Cirugía Cardiovascular de Guatemala in 2002. A retrospective review of medical records was performed. Each case was stratified into one of three surgical classes based upon customary practice in the United States of America. The outcome we measured was age at surgery, adjusting for the surgical class. Logistic regression was performed and odds ratios calculated. In univariate analyses, patients presented later for surgery if they were from rural areas (p equals 0.001), did not have social security membership (p equals 0.004), or paid any amount towards the cost of their surgery (p less than 0.001). Age at surgery was also positively correlated with the distance of the home of the patient from the surgical centre (p equals 0.002). For the subset of patients who applied for financial assistance, we found that children presented later for surgery if they required institutional support (p equals 0.001), or came from households of larger size (p less than 0.001). Guatemalan children with congenital cardiac disease may be at risk for delayed surgical care if they come from rural areas, areas distant from the surgical centre, or from families without membership of social security.

Hypertonic-Hyperoncotic Solutions Improve Cardiac Function in Children After Open-Heart Surgery

Hypertonic-Hyperoncotic Solutions Improve Cardiac Function in Children After Open-Heart Surgery

Current insights regarding neurological and developmental abnormalities in children and young adults with complex congenital cardiac disease

Over a decade ago, I co-authored a review in Cardiology in the Young regarding neurological outcomes following surgery for congenital cardiac disease.1In that review, I placed much emphasis on the conduct of cardiopulmonary bypass, and its role in neurodevelopmental disabilities. Much has been learned in the intervening years regarding the multifactorial causes of abnormal school-age development, in particular, the role of prenatal, perioperative, socioeconomic, and genetic influences. In this update, I will highlight some of the recent advances in our understanding of the protean causes of neurological, behavioral, and developmental abnormalities in children and young adults with complex forms of congenital cardiac disease. In addition, I will summarize the current data on patients at particular high-risk for adverse neurodevelopmental outcomes, specifically those with a functionally univentricular heart who have had staged reconstruction with ultimate conversion to the Fontan circulation.

Emergency hospital admissions and three-year survival of adults with and without cardiovascular surgery for congenital cardiac disease

Objective: This study determined the quantity and nature of emergencies leading to unscheduled hospital admissions of adults with congenital cardiac disease and their mid-term survival. Results During 1 year, 429 adults with congenital cardiac diseases were admitted 571 times, and 124 admissions (22%) of 95 patients (22%) were emergency admissions. Fifteen of the 95 patients were seen for the first time in 1 of the participating centers. The underlying anomalies were Fallot's tetralogy and pulmonary atresia (n = 26/7), univentricular heart after Fontan procedure (n = 25), atrial septal defect (n = 18), Eisenmenger syndrome (n = 12), complete transposition (n = 11), and others (n = 25). Indications for admission were cardiovascular complications (n = 103; 83%) (arrhythmia, cardiac failure, syncope, pacemaker problems, pericardial tamponade, and sudden death), infections (n = 8, 6%) (endocarditis, pacemaker infection, pneumonia, and cerebral abscess), acute chest pain (n = 7; 6%), and acute abdominal pain (n = 4; 3%). All patients required immediate emergency care, and 16 patients (17%) required urgent cardiovascular or abdominal surgery. Six patients died during the hospital stay. During a follow-up of 2.9 years (SD 0.8), 16 (18%) of the discharged patients died, and 2 additional patients underwent heart or heart-lung transplantation. Conclusion Adults with congenital cardiac disease often experience serious emergency situations with a high in-hospital and mid-term post-hospital mortality. Care given by physicians with special expertise is important in this specific group of patients.

Whole blood ionized magnesium: age-related differences in normal values and clinical implications of ionized hypomagnesemia in patients undergoing surgery for congenital cardiac disease

Objectives: We sought to (1) determine reference values for whole blood ionized magnesium concentrations in newborns, children, and young adults and (2) evaluate the frequency and clinical implications of ionized hypomagnesemia in patients undergoing surgery for congenital heart disease. Method: We prospectively measured ionized magnesium concentrations in 299 subjects (113 control subjects and 186 patients undergoing surgery for congenital heart disease). Subjects were categorized by age. In the surgical group blood samples were obtained before bypass, during bypass (cooling and rewarming), after bypass, and during admission to the intensive care unit. Ionized hypomagnesemia was defined as ionized magnesium level 2 standard deviations below the mean of control subjects in the same age group. Patients were analyzed, controlling for cardiopulmonary bypass time. Results: In the control group ionized magnesium concentrations differed by age. Neonates and adults showed lower ionized magnesium concentrations compared with those of other age groups. Infants exhibited the highest ionized magnesium concentration. In the surgical group patients older than 1 month showed a higher proportion of ionized hypomagnesemia compared with that found in neonates at baseline ( P < .001), after bypass ( P = .03), and at admission to the intensive care unit ( P = .02). Controlling for cardiopulmonary bypass time, patients older than 1 month who were hypomagnesemic during bypass showed longer intubation time ( P = .001) and longer intensive care stay ( P = .01) and tended to have a higher pediatric severity of illness score on intensive care admission ( P = .14) compared with patients without ionized hypomagnesemia. Conclusions: There are age-related differences in normal ionized magnesium concentrations. Ionized hypomagnesemia is a common and clinically relevant occurrence among patients older than 1 month of age undergoing surgery for congenital heart disease. (J Thorac Cardiovasc Surg 2000;119:891-8)

Changes in whole blood lactate levels during cardiopulmonary bypass for surgery for congenital cardiac disease: An early indicator of morbidity and mortality

Objective: Our objective was to evaluate the change in lactate level during cardiopulmonary bypass and the possible predictive value in identifying patients at high risk of morbidity and mortality after surgery for congenital cardiac disease. Methods: We prospectively studied lactate levels in 174 nonconsecutive patients undergoing cardiopulmonary bypass during operations for congenital cardiac disease. Arterial blood samples were taken before cardiopulmonary bypass, during cardiopulmonary bypass (cooling and rewarming), after cardiopulmonary bypass, and during admission to the cardiac intensive care unit. Complicated outcomes were defined as open sternum as a response to cardiopulmonary instability, renal failure, cardiac arrest and resuscitation, extracorporeal membrane oxygenation, and death. Results: The largest increment in lactate level occurred during cardiopulmonary bypass. Lactate levels decreased between the postbypass period and on admission to the intensive care unit. Patients who had circulatory arrest exhibited higher lactate levels at all time points. Nonsurvivors had higher lactate levels at all time points. A change in lactate level of more than 3 mmol/L during cardiopulmonary bypass had the optimal sensitivity (82%) and specificity (80%) for mortality, although the positive predictive value was low. Conclusions: Hyperlactatemia occurs during cardiopulmonary bypass in patients undergoing operations for congenital cardiac disease and may be an early indicator for postoperative morbidity and mortality. (J Thorac Cardiovasc Surg 2000;119:155-62)

Atrial pacing as an adjunct to the management of post-surgical His bundle tachycardia.

To examine the benefits of restoring atrioventricular synchrony to children with His bundle tachycardia after operation for congenital heart disease. Review of clinical outcome of adopting the technique of R wave synchronised atrial pacing as an adjunct to the management of His bundle tachycardia from September of 1987 till June of 1990. Eleven consecutive children (aged between 3 days and 13 years) with haemodynamically significant His bundle tachycardia after cardiopulmonary bypass surgery. Atrial pacing synchronised either manually or automatically to the R wave of the His bundle tachycardia was implemented so that atrial depolarisation preceded the following R wave by an appropriate PR interval. An immediate and sustained increase in mean systemic blood pressure (average 15 mm Hg, range 6-30 mm Hg) was seen with the onset of atrial pacing in 10 of the 11 children. One child, who had undergone a Fontan procedure, developed atrial flutter shortly after the onset of atrial pacing and required direct current cardioversion. Four children died. Of the seven survivors, six have sustained sinus rhythm which returned between two and 10 days after the onset of tachycardia. One of the survivors has severe neurological impairment attributed to a period of low cardiac output during tachycardia; the others are alive and well. In those children who did badly the mean time between arrhythmia occurrence and the start of atrial pacing or cooling or both was nine hours; in those who did well it was one hour. Atrial pacing synchronous with the His bundle is a useful adjunct in the management of children with His bundle tachycardia after surgery for congenital cardiac disease.