Extracorporeal membrane oxygenation, Berlin, and ventricular assist devices: a primer for the cardiologist.

PURPOSE OF REVIEW: Mechanical circulatory support (MCS) has become an indispensable tool in the management of children with impending respiratory and cardiac failure. Though extracorporeal membrane oxygenation (ECMO) was classically the only form of support available to pediatric patients, considerable advances have allowed ventricular assist devices (VADs) to become increasingly utilized in children. This review provides an update of recent advances in ECMO and VAD management in children. RECENT FINDINGS: The options for mechanical support in infants and small children with end-stage heart failure are limited. As such, the greatest advances in the past decade have come in the successful adoption of the Berlin Heart EXCOR device, with a marked improvement in survival to transplant over ECMO. Further advances have been made in the use of adult VADs in children. For instance, the HeartWare HVAD has been utilized in children as young as 3 years of age, despite being designed for use in adult patients. SUMMARY: The availability of mechanical support options for children remains limited to ECMO and a small number of VADs. While outcomes of VAD support in pediatric patients have been promising, further study in smaller and more complex pediatric patients is necessary.

DMD mutation and LTBP4 haplotype do not predict onset of left ventricular dysfunction in Duchenne muscular dystrophy.

Cardiomyopathy develops in >90% of Duchenne muscular dystrophy (DMD) patients by the second decade of life. We assessed the associations between DMD gene mutations, as well as Latent transforming growth factor-beta-binding protein 4 (LTBP4) haplotypes, and age at onset of myocardial dysfunction in DMD. DMD patients with baseline normal left ventricular systolic function and genotyping between 2004 and 2013 were included. Patients were grouped in multiple ways: specific DMD mutation domains, true loss-of-function mutations (group A) versus possible residual gene expression (group B), and LTBP4 haplotype. Age at onset of myocardial dysfunction was the first echocardiogram with an ejection fraction <55% and/or shortening fraction <28%. Of 101 DMD patients, 40 developed cardiomyopathy. There was no difference in age at onset of myocardial dysfunction among DMD genotype mutation domains (13.7±4.8 versus 14.3±1.0 versus 14.3±2.9 versus 13.8±2.5, p=0.97), groups A and B (14.4±2.8 versus 12.1±4.4, p=0.09), or LTBP4 haplotypes (14.5±3.2 versus 13.1±3.2 versus 11.0±2.8, p=0.18). DMD gene mutations involving the hinge 3 region, actin-binding domain, and exons 45-49, as well as the LTBP4 IAAM haplotype, were not associated with age of left ventricular dysfunction onset in DMD.

Reducing Pediatric Sternal Wound Infections: A Quality Improvement Project.

OBJECTIVES: To evaluate whether a quality improvement intervention reduces sternal wound infection rates in children after cardiac surgery. DESIGN: This is a pre- and postintervention quality improvement study. SETTING: A 16-bed cardiac ICU in a university-affiliated pediatric tertiary care children's hospital. PATIENTS: All patients undergoing cardiac surgery via median sternotomy from January 2010 to December 2014 are included. The sternal wound infection rates for primary closure and delayed sternal closure are reported per 100 sternotomies. The hospital-acquired infection records were used to identify preintervention cases, while postintervention cases were collected prospectively. INTERVENTION: Implementation of a sternal wound prevention bundle during the preoperative, intraoperative, and postoperative periods for cardiac surgical cases. MEASUREMENTS AND MAIN RESULTS: During the preintervention period, 32 patients (3.8%) developed sternal wound infection, whereas only 19 (2.1%) developed sternal wound infection during the postintervention period (p = 0.04). The rates of sternal wound infection following primary closure were not significantly different pre- and postintervention (2.4% vs 1.6%; p = 0.35). However, patients with delayed sternal closure had significantly lower postintervention infection rates (10.6% vs 3.9%; p = 0.02). CONCLUSIONS: Implementation of a sternal wound prevention bundle during the perioperative period was associated with lower sternal wound infection rates in surgeries with delayed sternal closure.

Alteration of Cardiac Deformation in Acute Rejection in Pediatric Heart Transplant Recipients.

The objective of this study is to assess changes in cardiac deformation during acute cellular- and antibody-mediated rejection in pediatric HT recipients. Pediatric HT recipients aged ≤18 years with at least one episode of biopsy-diagnosed rejection from 2006 to 2013 were included. Left ventricular systolic S (SS) and SR (SSr) data were acquired using 2D speckle tracking on echocardiograms obtained within 12 h of right ventricular endomyocardial biopsy. A mixed effect model was used to compare cardiac deformation during CR (Grade ≥ 1R), AMR (pAMR ≥ 2), and mixed rejection (CR and AMR positive) versus no rejection (Grade 0R and pAMR 0 or 1). A total of 20 subjects (10 males, 50%) with 71 rejection events (CR 35, 49%; AMR 21, 30% and mixed 15, 21%) met inclusion criteria. The median time from HT to first biopsy used for analysis was 5 months (IQR 0.25-192 months). Average LV longitudinal SS and SSr were reduced significantly during rejection (SS: -17.2 ± 3.4% vs. -10.7 ± 4.5%, p < 0.001 and SSr: -1.2 ± 0.2 s- 1 vs. -0.9 ± 0.3 s- 1; p < 0.001) and in all rejection types. Average LV short-axis radial SS was reduced only in CR compared to no rejection (p = 0.04), while average LV circumferential SS and SSr were reduced significantly in AMR compared to CR (SS: 18.9 ± 4.2% vs. 20.8 ± 8.8%, p = 0.03 and SSr: 1.35 ± 0.8 s- 1 vs. 1.54 ± 0.9 s- 1; p = 0.03). In pediatric HT recipients, LV longitudinal SS and SSr were reduced in all rejection types, while LV radial SS was reduced only in CR. LV circumferential SS and SSr further differentiated between CR and AMR with a significant reduction seen in AMR as compared to CR. This novel finding suggests mechanistic differences between AMR- and CR-induced myocardial injury which may be useful in non-invasively predicting the type of rejection in pediatric HT recipients.

Lifetime cardiac reinterventions following the Fontan procedure.

Patients with single ventricle physiology face significant morbidity and mortality following the Fontan procedure resulting in the need for additional cardiac reinterventions. Online patient education resources provide limited information on the reinterventions performed in single ventricle patients following the Fontan procedure. We sought to determine cardiac surgical and percutaneous reintervention rates and factors affecting reinterventions following the Fontan procedure. Databases from a single tertiary care center were retrospectively reviewed for all patients who underwent a Fontan procedure between 1978 and 2002. The number and type of cardiac surgical and percutaneous interventions following the Fontan procedure were determined, and relationships between need for reintervention and clinical variables were sought. A total of 91 patients (55 males) underwent the Fontan procedure at a median age of 5.50 years (IQR: 3.33-9.50 years). Median age at last follow-up, death, or transplant was 21.89 years (IQR: 10.87-25.51 years). Following the Fontan procedure, 60 (66%) patients required an additional 144 median sternotomies and 61 (67%) required 139 percutaneous cardiac interventions. Pacemaker system placement/replacement was the most common intervention following the Fontan procedure. The median time to first cardiac surgery following the Fontan was 1.96 years (IQR: 0.06-8.42 years) while the median time to the first percutaneous intervention was 7.63 years (IQR: 0.65-15.89 years). Families of single ventricle patients should be counseled on the likelihood of requiring additional cardiac interventions following the Fontan procedure.

Contemporary Early Postoperative Cone Repair Outcomes for Patients With Ebstein Anomaly.

OBJECTIVE: To describe the early postoperative outcomes after cone repair (CR) for Ebstein anomaly (EA) across the age spectrum. PATIENTS AND METHODS: For this study, 284 patients from 1 to 73 years of age who underwent CR at Mayo Clinic from June 1, 2007, to December 21, 2018, were separated by age group (1-<4, 4-<19, 19-<40, and 40+ years) and by disease severity for analysis. Outcomes of interest included death, reoperation, readmission, early postoperative complications, cardiac intensive care unit and hospital length of stay, and need for superior cavopulmonary anastomosis. RESULTS: Mortality within 30 days was 0%. The reoperation rate was 4.9% (n=14) and the median hospital length of stay was 5 days, with no statistical difference between ages at time of CR or severity groups. The readmission rate was 2% (n=6). Postoperative complications were seen in 8.8% (n=25) of cases overall, with higher rates in the youngest age group (21%, P<.001). Superior cavopulmonary anastomosis was most common in the youngest age group (37% vs 17% overall, P<.001) and in those with severe disease (35%, P<.001). CONCLUSION: Children and adults with Ebstein anomaly have very good early postoperative outcomes with a less than 10% complication and reoperation rate and very low mortality following cone reconstruction. In the setting of good and stable right ventricle function and no symptoms of heart failure or cyanosis, waiting for CR until 4 years of age may minimize early postoperative complications and need for superior cavopulmonary anastomosis.

A 7-Year-Old Boy with Fever and Dark Urine.

A 7-Year-Old Boy with Fever and Dark UrineA 7-year-old boy with surgically repaired tetralogy of Fallot presented for evaluation of fever and dark urine. How do you approach the evaluation, and what is the diagnosis?

Outcomes of Primary vs Secondary Delayed Sternal Closure in Pediatric Cardiac Surgery.

BACKGROUND: Delayed sternal closure (DSC) is a management strategy for hemodynamic instability and severe coagulopathy after complex congenital heart surgery. We hypothesized that DSC results in better outcomes than perioperative sternal reopening. METHODS: We reviewed patients aged <18 years old undergoing cardiac surgery 2007-2017 at our institution. A total of 179 patients (3.8%) had primary DSC (PDSC, sternum left open after initial operation) and 45 patients (0.9%) had secondary DSC (SDSC, sternum closed primarily and reopened perioperatively). Perioperative characteristics and outcomes among PDSC ≤2 days (98 patients), PDSC >2 days (81 patients), and SDSC (45 patients) were analyzed. RESULTS: Median age was 120 days (range, 3-6553 days) and median DSC duration was 2 days (range, 1-60 days). The PDSC >2 days group was the youngest group, and the distribution of procedures was different between groups. Indications for DSC were hemodynamic instability in 152 patients (67.9%) and severe coagulopathy in 33 patients (14.7%), with no difference between groups (P = .141). Extracorporeal membrane oxygenation use was higher in the PDSC >2 days group than the other groups (47.5% vs 7.1%, P < .01 and 47.5% vs 28.9%, P = .02), respectively. Operative mortality was higher in SDSC compared to the other groups (17.8% vs 0% for PDSC ≤2 and 6.2% for PDSC >2 days, P < .01). Hospital stay was longer in SDSC (57 ± 7 days) than PDSC ≤2 days (22 ± 5 days) and PDSC >2 days (44 ± 6, P = .01). Survival was better in PDSC regardless of duration than SDSC. CONCLUSIONS: PDSC demonstrated better outcomes than SDSC. Sternal reopening can be life-saving, but, when anticipated, PDSC can yield better outcomes.

Preoperative Management of Neonates With Congenital Heart Disease.

Clinicians caring for neonates with congenital heart disease encounter challenges in clinical care as these infants await surgery or are evaluated for further potential interventions. The newborn with heart disease can present with significant pathophysiologic heterogeneity and therefore requires a personalized therapeutic management plan. However, this complex field of neonatal-cardiac hemodynamics can be simplified. We explore some of these clinical quandaries and include specific sections reviewing the anatomic challenges in these patients. We propose this to serve as a primer focusing on the hemodynamics and therapeutic strategies for the preoperative neonate with systolic dysfunction, diastolic dysfunction, excessive pulmonary blood flow, obstructed pulmonary blood flow, obstructed systemic blood flow, transposition physiology, and single ventricle physiology.

What Factors Should Be Considered to Improve Outcome of Mechanical Mitral Valve Replacement in Children?

OBJECTIVE: To identify risk factors for pediatric mechanical mitral valve replacement (mMVR) to improve management in this challenging population. METHODS: From 1993 to 2019, 93 children underwent 119 mMVR operations (median age, 8.8 years [interquartile range [IQR]: 2.1-13.3], 54.6% females) at our institution. Twenty-six (21.8%) patients underwent mMVR at ≤2 years and 93 (78.2%) patients underwent mMVR at >2 years. Median follow-up duration was 7.6 years [IQR: 3.2-12.4]. RESULTS: Early mortality was 9.7%, but decreased with time and was 0% in the most recent era (13.9% from 1993 to 2000, 7.3% from 2001 to 2010, 0% from 2011 to 2019, P = .04). It was higher in patients ≤2 years compared to patients >2 years (26.9% vs 2.2%, P < .01). On multivariable analysis for mitral valve reoperation, valve size <23 mm was significant with a hazard ratio of 5.38 (4.87-19.47, P = .01);. Perioperative stroke occurred in 1% and permanent pacemaker was necessary in 12%. Freedom from mitral valve reoperation was higher in patients >2 years and those with a prosthesis ≥23 mm. Median time to reoperation was 7 years (IQR: 4.5-9.1) in patients >2 years and 3.5 years (IQR: 0.6-7.1) in patients ≤2 years (P = .0511), but was similar between prosthesis sizes (P = .6). During follow-up period (median 7.6 years [IQR: 3.2-12.4], stroke occurred in 10%, prosthetic valve thrombosis requiring reoperation in 4%, endocarditis in 3%, and bleeding in 1%. CONCLUSION: Early and late outcomes of mMVR in children are improved when performed at age >2 years and with prosthesis size ≥23 mm. These factors should be considered in the timing of mMVR.

Adults With Tetralogy of Fallot: Early Postoperative Outcomes and Risk Factors for Complications.

OBJECTIVE: To report the early postoperative outcomes in adults with tetralogy of Fallot (TOF) undergoing cardiac surgery and to identify patient factors associated with complications. PATIENTS AND METHODS: We performed a single-institution retrospective review of adults with TOF who underwent cardiac surgery from January 8, 2008, through June 21, 2018. Patients' characteristics, preoperative imaging, surgical interventions, outcomes, and complications were analyzed. RESULTS: There were 219 adults with TOF (mean age, 40 years; range, 18-83 years; 88 [40%] female) in the study. Surgical interventions included repair or replacement of the pulmonary valve (n=199 [91%]), tricuspid valve (n=70 [32%]), mitral valve (n=13 [5.9%]), and aortic valve (n=8 [3.7%]). Three patients (1.4%) underwent first-time TOF repair. The 30-day mortality rate was 1.4% (n=3). Early postoperative complications occurred in 66 (30%) and included arrhythmias requiring treatment, dialysis requirement, liver dysfunction, respiratory failure, infection, reoperation, cardiac arrest, mechanical circulatory support, and death. Multivariate analysis found older age at current surgery (odds ratio [OR], 1.04 per year; 95% CI, 1.01 to 1.06; P<.001), longer cardiopulmonary bypass time (OR, 1.01 per minute; 95% CI, 1.01 to 1.02; P<.001), right ventricular systolic dysfunction (OR, 1.31; 95%, CI 1.02 to 1.69; P=.03), diabetes mellitus (OR, 3.50; 95% CI, 1.20 to 10.2; P=.02), and history of initial palliative surgery (OR, 1.99; 95% CI, 1.01 to 3.91; P=.05) as independent predictors of complications. CONCLUSION: Surgical interventions for adult patients with TOF can be performed with low early morbidity and mortality. Clinical characteristics and preoperative testing parameters can predict risk for complications in the postoperative period.

Temporary bronchial stenting for airway compression in the interstage palliation of functional single ventricle.

The Norwood procedure is the first of three palliative surgical procedures offered for hypoplastic left heart syndrome (HLHS). Due to the small size of the thorax and proximity of airway and vascular structures, compression of the airway is possible following the Norwood procedure. We describe the management of an infant with HLHS following Stage I surgical palliation who developed refractory respiratory failure secondary to severe left bronchial compression.

Innovative 2-Step Management Strategy Utilizing EXIT Procedure for a Fetus With Hypoplastic Left Heart Syndrome and Intact Atrial Septum.

Hypoplastic left heart syndrome (HLHS) with intact atrial septum (HLHS-IAS) carries a high risk of mortality and affects about 6% of all patients with HLHS. Fetal interventions, postnatal transcatheter interventions, and postnatal surgical resection have all been used, but the mortality risk continues to be high in this subgroup of patients. We describe a novel, sequential approach to manage HLHS-IAS and progressive fetal hydrops. A 28-year-old, gravida 4 para 2 mother was referred to Mayo Clinic for fetal HLHS. Fetal echocardiography at 28 weeks of gestation demonstrated HLHS-IAS with progressive fetal hydrops. The atrial septum was thick and muscular with no interatrial communication. Ultrasound-guided fetal atrial septostomy was performed with successful creation of a small atrial communication. However, fetal echocardiogram at 33 weeks of gestation showed recurrence of a pleural effusion and restriction of the atrial septum. We proceeded with an Ex uteroIntrapartum Treatment (EXIT) delivery and open atrial septectomy. This was performed successfully, and the infant was stabilized in the intensive care unit. The infant required venoarterial extracorporeal membrane oxygenator support on day of life 1. The patient later developed hemorrhagic complications, leading to his demise on day of life 9. This is the first reported case of an EXIT procedure and open atrial septectomy performed without cardiopulmonary bypass for an open-heart operation and provides a promising alternative strategy for the management of HLHS-IAS in select cases.

Abnormal location of umbilical venous catheter due to Scimitar syndrome.

Scimitar syndrome is a rare congenital anomaly where the right pulmonary veins return to the inferior vena cava (IVC) just below the diaphragm. On chest X-ray (CXR), an IVC catheter will be in a bizarre location outside the heart if it inadvertently passes into the scimitar vein rather than into the right atrium.

Living at altitude adversely affects survival among patients with a Fontan procedure.

OBJECTIVES: This study sought to determine whether survival in this cohort of patients was adversely affected by increased residential altitude. BACKGROUND: The success of the Fontan procedure depends in large part on low pulmonary vascular resistance (PVR). Factors that increase PVR, including an increase in residential altitude, may adversely affect long-term outcome. Higher altitude has been shown to affect functional well-being in patients with a Fontan circulation. METHODS: Databases from a tertiary cardiac care center in the Intermountain West (elevation 5,000 feet) were analyzed for patients born with single-ventricle anatomy who would now be of adult age. Complete data were then collected on all identified patients who subsequently underwent the Fontan operation. Correlates of, and time to, adverse outcome, defined as death, cardiac transplantation, or clinical decompensation requiring a move to sea level, were determined. RESULTS: Of 149 patients with single-ventricle anatomy, 103 underwent the Fontan procedure, with 70 surviving to adulthood at moderate altitude. Adverse outcome occurred in 55, with death in 24 (23%), cardiac transplantation in 18 (17%), and clinical decompensation requiring move to sea level in 13 (13%). There was no relationship between type, age at, or era of Fontan procedure and long-term outcome. Correlates of long-term, transplant-free survival at moderate altitude included lower residential altitude (4,296 vs. 4,637 feet, p < 0.001), and lower pulmonary artery pressures before the Fontan procedure (13 vs. 15 mm Hg, p = 0.01), and after (14 vs. 18 mm Hg, p = 0.01). CONCLUSIONS: Long-term outcome after the Fontan procedure is adversely impacted by higher residential altitude.

QTc values among children and adolescents presenting to the emergency department.

OBJECTIVE: Long-QT syndrome (LQTS) is both underdiagnosed and overdiagnosed. Many patients are incorrectly diagnosed as having LQTS after presenting to an emergency department (ED) with presyncope/syncope and demonstrating "borderline" QT-interval prolongation (QTc ≥ 440 milliseconds) in a sentinel ED-obtained electrocardiogram (ECG). We sought to evaluate the distribution and clinical significance of QT intervals in the ED. METHODS: We retrospectively reviewed data for all patients 22 years of age or younger (N = 626; 369 females; age, mean ± SD: 17 ± 5 years) who had ECGs obtained in our ED between July 1, 2007, and June 30, 2008. A total of 223 patients were excluded because of known structural heart disease, arrhythmias, electrolyte abnormalities, or exposure to QT-interval-prolonging medications. RESULTS: The average QTc was 428 ± 28 milliseconds (range: 344-566 milliseconds), and approximately one-third of patients had QTc values of ≥440 milliseconds (females: 41%; males: 21%). Overall, 104 patients presented with presyncope/syncope, of whom 14 (13%) had follow-up ECGs. On follow-up, these patients demonstrated significant decreases in QTc values of 33 ± 43 milliseconds (P < .04). Only 8 (31%) of 26 patients with presyncope/syncope with borderline QT values had follow-up ECGs performed, in 5 of which the QTc values were decreased significantly. No patients ultimately received LQTS diagnoses. CONCLUSIONS: In the ED setting, approximately one-third of pediatric patients exhibited QTc values of ≥440 milliseconds and had significant normalization of QTc values in follow-up evaluations. First-time ECGs obtained after a syncopal episode must be interpreted with caution, particularly in the context of so-called borderline QT intervals.

Selective fiberoptic left main-stem intubation to treat bronchial laceration in an extremely low birth weight neonate.

A neonate born at 24 weeks gestation developed a right tension pneumothorax that persisted despite the placement of multiple thoracostomy tubes, the use of high-frequency ventilation and postural therapy. On day-of-life 11, bedside bronchoscopy revealed a laceration at the junction of the trachea and right main-stem bronchus. Under fiberoptic guidance the left main-stem bronchus was intubated. Single-lung ventilation then was employed for 24h, after which time the pneumothorax never recurred. We postulate that the diversion of positive-pressure ventilation away from the laceration site allowed the surrounding injury-induced granulation tissue to create a seal and facilitate closure of the defect.