Oral Enoximone as an Alternative to Protracted Intravenous Medication in Severe Pediatric Myocardial Failure.

Phosphodiesterase 3 inhibitors have been used successfully in pediatric patients with acute or chronic myocardial dysfunction over the last two decades. Their protracted continuous intravenous administration is associated with risk of infectious and thromboembolic complications. Weaning intravenous medication and starting oral angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers can be challenging. We reviewed retrospectively hospital records of 48 patients receiving oral enoximone treatment in a single tertiary pediatric cardiac center between November 2005 and April 2014. Failure to wean from intravenous milrinone infusion and/or intolerance of ACE inhibitors and/or beta-blockers was indications for oral enoximone treatment. Age of the patients ranged between 0.5 and 191 months (median 7.5 months) at the time of starting enoximone treatment. There were 14 patients (29 %) with left ventricular dysfunction due to myocarditis or dilated cardiomyopathy and 34 patients (71 %) with myocardial dysfunction complicating congenital heart disease. Fifteen (44 %) of these 34 patients had left ventricular dysfunction, 13 (38 %) right ventricular dysfunction, and in 6 (18 %) both ventricles were failing. Duration of oral enoximone treatment was between 3 days and 34 months (median of 2.3 months). Myocardial functional recovery allowed for weaning of enoximone treatment in 15 patients (31 %) after 6 days-15 months (median 5 months). No adverse hemodynamic effects were noted. Blood stained gastric aspirates encountered in two patients resolved with concomitant milk administration. Based on our limited experience, oral enoximone is a well-tolerated and promising alternative to intravenous medication and/or other commonly used oral medications in selected pediatric patients with chronic heart failure.

Novel postoperative use of beta-blocking medication for infants with left ventricular outflow obstruction and diastolic myocardial dysfunction.

Severe left ventricular outflow obstruction often is associated with diastolic left ventricular myocardial dysfunction and tachycardia despite successful initial treatment. The authors have used esmolol to lower heart rate in this setting for successful weaning of patients from ventilation in postoperative recovery. Their limited experience supports the beneficial effect of continuous esmolol administration on infants with persistent tachycardia and severe left ventricular diastolic dysfunction in postoperative cardiac intensive care.

Use of surveillance criteria reduces interstage mortality after the Norwood operation for hypoplastic left heart syndrome.

OBJECTIVES: While hospital mortality after the Norwood operation for hypoplastic left heart syndrome (HLHS) has decreased steadily, interstage mortality until the superior cavopulmonary anastomosis (SCPA) remains a major concern. Our aim was to institute a home surveillance programme to decrease interstage mortality. METHODS: We enrolled 45 HLHS patients surviving the Norwood operation into our home surveillance programme and compared them with 97 patients treated before the initiation of the programme and with a third group of 20 patients not discharged between the first- and the second-stage operation. While still in hospital, parents were taught to record weight and fluid intake as well as oxygen saturations with the help of a vital sign monitor. During the last week of the hospital stay, the following criteria had to be met: oxygen saturation >75%, weight gain of at least 20-30 g in 3 days and a maximum weight loss of 30 g in a day. After discharge, these criteria had to be maintained at all times or the parents were supposed to call our hospital. Additionally, an experienced paediatric cardiologist from our centre called the parents at home once a week. RESULTS: Interstage mortality was reduced significantly from 12.4% (12/97) to 2.2% (1/45) (P = 0.042). The number of patients, who were not discharged before the SCPA, was significantly higher after the start of the home surveillance programme (12/57 vs. 8/105, P = 0.022). After discharge, 14 (31%) infants breached the surveillance criteria. Of these, one patient died and eight patients were operated earlier (SCPA, n = 6; shunt replacement, n = 2). The remaining five patients could be discharged home after observation. Children in the home surveillance programme were younger [102 (67-299) vs. 152 (77-1372) days, P = 0.001] and weighed less (5.09 ± 0.79 vs. 5.75 ± 1.22 kg, P = 0.001) at the SCPA compared with the remainder. Early survival after SCPA was not different. CONCLUSIONS: The home surveillance programme led to an important decrease in interstage mortality. The adherence to the surveillance criteria before discharge resulted in a larger number of patients receiving inpatient treatment until SCPA. Earlier SCPA in the surveillance group had no negative impact on early survival after SCPA.

Hypoplastic left heart syndrome: current considerations and expectations.

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

Risk factors for adverse outcome after superior cavopulmonary anastomosis for hypoplastic left heart syndrome.

OBJECTIVE: Outcome of staged palliation for hypoplastic left heart syndrome (HLHS) has improved over the past decades. We sought to evaluate the outcome of the second palliative procedure, the superior cavopulmonary anastomosis (SCPA), in a single-centre cohort and to identify risk factors for adverse outcome. METHODS: Full data on all 119 HLHS patients who underwent SCPA in our centre between January 1996 and December 2007 were analysed. RESULTS: Early adverse outcome (death or cardiac transplant within 30 days after surgery or before hospital discharge) was 3.4%. Late adverse outcome (death or transplant after hospital discharge but before the next operative procedure) was 8.7%. Postoperative complications occurred in 30% of patients (n = 36), with transient arrhythmia (n = 11; 9%) and pulmonary artery stenosis or thrombosis (n = 10; 8%) being the most common. The presence of more than moderate tricuspid valve regurgitation after surgery proved to be a strong predictor of late adverse outcome (odds ratio (OR) 16.5 (4.4-62.6), P < 0.001). SCPA at less than 4 months of age did not increase the risk for adverse outcome (OR 1.2 (0.4-3.6), P = 0.78) but increased the risk for postoperative complications (OR 6.3 (2.3-14.9), P < 0.001). CONCLUSIONS: SCPA can nowadays be performed in HLHS patients with low mortality. However, more than moderate tricuspid valve regurgitation should be targeted at surgery as it is a risk factor for adverse outcome such as death or need for cardiac transplant. SCPA should ideally be performed in children older than 4 months to minimise the risk of postoperative complications.

Perioperative cerebral and somatic oxygenation in neonates with hypoplastic left heart syndrome or transposition of the great arteries.

OBJECTIVE: Significant depression in cerebral oxygen saturation has been observed in patients with hypoplastic left heart syndrome (HLHS) undergoing Norwood operations. We monitored cerebral oxygen saturation with near-infrared spectroscopy before and after this procedure. Patients with transposition of great arteries (TGA) before and after arterial switch operation were also studied to elucidate whether post-cardiopulmonary bypass (CPB) changes in cerebral oxygen saturation are related to CPB or hemodynamic alterations inherent in single-ventricle physiology. METHODS: We monitored 33 patients with HLHS and 20 with TGA 24 hours before and 48 hours after CPB. In addition to cerebral oxygen saturation, routine measurements of oxygen transport and delivery were performed. RESULTS: Preoperatively, cerebral oxygen saturation was higher in patients with HLHS than with TGA (61% ± 7% vs 56% ± 8%, P = .04). After CPB, cerebral oxygen saturation was markedly depressed in both groups but increased toward end of monitoring (HLHS vs TGA minimal value 42% ± 12% vs 54% ± 11%, P < .001, value 48 hours after CPB 62% ± 7% vs 80% ± 8%, P < .0001). Routine measures of oxygen delivery, such as arterial and central venous oxygen saturations, were similar at minimal cerebral oxygen saturation and 48 hours after CPB. CONCLUSIONS: Depression of cerebral oxygen saturation is prevalent among neonates with congenital heart disease regardless of whether univentricular or biventricular circulation is present, suggesting that cerebral desaturation is mainly induced by CPB's effect on cerebral blood flow. Routine measures of oxygen delivery fail to indicate cerebral desaturation.

The impact of afterload reduction on the early postoperative course after the Norwood operation - a 12-year single-centre experience.

OBJECTIVE: The objective of this study was to analyse the postoperative course and early outcome after the Norwood operation for patients with hypoplastic left heart syndrome. We particularly aimed to assess the impact of surgical and pharmacological modifications introduced. METHODS: Of 157 patients who underwent the Norwood operation between January 1996 and December 2007, postoperative intensive care data on haemodynamics, pharmacological support and ventilation were analysed from 146 patients (six patients died intra-operatively and data were incomplete in five). The cohort was divided into three groups depending on the surgical method and type of afterload reduction. Patients of group 1 (n=39, January 1996-December 1999) were operated with deep hypothermic circulatory arrest. In patients of group 2 (n=59, January 2000-June 2003) and group 3 (n=59, July 2003-December 2007) antegrade selective cerebral perfusion was used. Patients of groups 1 and 2 received sodium nitroprusside to reduce afterload; in group 3 phentolamine was used. RESULTS: There were no differences between the groups in terms of preoperative status and anatomy, except a higher incidence of prenatal diagnosis between groups 3 and 1. The duration and dosage of sodium nitroprusside administration were similar in groups 1 and 2. The median duration of afterload reduction was significantly longer in group 3 compared with both the other groups (72 h (range: 24-201 h) vs 48 h (range: 8-145 h) and 48 h (range: 4-173 h), respectively). The median ventilation times was shorter in group 2 compared with group 1 (61 h (range: 16-1191 h) vs 119 h (range: 26-648 h)). During the first 36 postoperative hours, the mean arterial blood pressure and coronary perfusion pressure were significantly lower in group 3 than in group 1 (50.7+/-4.8 and 28+/-3.7 mmHg vs 53.6+/-5.2 and 31.4+/-4.3 mmHg), but, in patients of group 3, the time period to consistently reach a mean arteriovenous oxygen difference below 5 ml dl(-1) was markedly shorter than in the other groups (group 3: 12h 4.90+/-1.97 ml dl(-1); group 1: 24h 4.53+/-2.25 ml dl(-1) and group 2: 24h 4.57+/-2.04 ml dl(-1)). Complication rates were similar between the groups. However, 30-day mortality decreased over the study period to an exponentially weighted moving average of 2.3%. CONCLUSION: Adamant afterload reduction improves systemic blood flow early after the Norwood operation and may have contributed to the reduction in early postoperative mortality achieved over 12 years.

Exercise capacity of a contemporary cohort of children with hypoplastic left heart syndrome after staged palliation.

OBJECTIVE: Outcome of staged palliation for hypoplastic left heart syndrome has improved over the past decades. However, only little is known about the exercise capacity of children with palliated hypoplastic left heart syndrome where a systemic right ventricle supports the systemic circulation. The aim of the study was to assess exercise capacity in a contemporary cohort of children with hypoplastic left heart syndrome palliated in a single centre according to a uniform surgical strategy. METHODS: Standardised cardiopulmonary exercise testing on a treadmill was performed in 46 consecutive hypoplastic left heart patients (median age: 6.0 (4.1-11.4) years). All but one patient reached the anaerobic threshold. Exercise data were compared to normal values obtained with a similar exercise protocol in a large cohort of paediatric volunteers. RESULTS: Oxygen uptake at anaerobic threshold (26.9+/-6.0 ml kg(-1)min(-1); 74.5+/-18.2% of predicted) and maximal oxygen uptake (31.0+/-6.8 ml kg(-1)min(-1); 60.8+/-15.0% of predicted) were significantly reduced compared with controls (P<0.0001 for both). The limitation in exercise capacity was due to an impaired rise in heart rate (158+/-23 bpm; 79.7+/-11.5% of predicted; P<0.0001) and oxygen pulse (4.5+/-1.6 ml per beat; 85.5+/-22.0% of predicted; P<0.0001). Furthermore, respiration during exercise was inefficient with an elevated respiratory rate and reduced maximal tidal volume and minute ventilation at maximal exercise. CONCLUSIONS: The exercise capacity of children with hypoplastic left heart syndrome is markedly reduced. Limitations in heart rate increase and stroke volume augmentation are the major contributors to this. An abnormal ventilatory response to exercise also adds to their limitation in exercise tolerance. However, the degree of physical disability does not justify discouraging these patients from school and leisure sports.