Impact of Right Ventricular Surface Area-to-Volume Ratio on Ventricular Remodeling After Pulmonary Valve Replacement.

Optimal reverse remodeling of the right ventricle (RV), a sentinel goal of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot, is not fully predicted by volume-based pre-PVR parameters. Our objectives were to characterize novel geometric RV parameters in patients receiving PVR and in controls, and to identify associations between these parameters and chamber remodeling post-PVR. Secondary analysis was performed on cardiac magnetic resonance (CMR) data from 60 patients enrolled in a randomized trial of PVR with and without surgical RV remodeling. 20 healthy age-matched subjects served as controls. The primary outcome was optimal post-PVR RV remodeling (end-diastolic volume index (EDVi) ≤ 114 ml/m2 and ejection fraction (EF) ≥ 48%) vs. suboptimal remodeling (EDVi ≥ 120 ml/m2 and EF ≤ 45%). RV geometry was markedly different at baseline in PVR patients compared with controls, with lower systolic surface area-to-volume ratio (SAVR) (1.16 ± 0.26 vs.1.44 ± 0.21 cm2/mL, p < 0.001) and lower systolic circumferential curvature (0.87 ± 0.27 vs. 1.07 ± 0.30 cm- 1, p = 0.007) but similar longitudinal curvature. In the PVR cohort, higher systolic SAVR was associated with higher RVEF both pre- and post-PVR (p < 0.001). Among PVR patients, 15 had optimal and 19 had suboptimal remodeling post-PVR. Multivariable modeling showed that among the geometric parameters, higher systolic SAVR (OR 1.68 per 0.1 cm2/mL increase; p = 0.049) and shorter systolic RV long-axis length (OR 0.92 per 0.1 cm increase; p = 0.035) were independently associated with optimal remodeling. Compared with controls, PVR patients have lower SAVR and lower circumferential but not longitudinal curvature. Higher pre-PVR systolic SAVR is associated with optimal remodeling post-PVR.

Impact of pulmonary valve replacement on left ventricular rotational mechanics in repaired tetralogy of Fallot.

BACKGROUND: In repaired tetralogy of Fallot (rTOF), abnormal left ventricular (LV) rotational mechanics are associated with adverse clinical outcomes. We performed a comprehensive analysis of LV rotational mechanics in rTOF patients using cardiac magnetic resonance (CMR) prior to and following surgical pulmonary valve replacement (PVR). METHODS: In this single center retrospective study, we identified rTOF patients who (1) had both a CMR ≤ 1 year before PVR and ≤ 5 years after PVR, (2) had no other intervening procedure between CMRs, (3) had a body surface area > 1.0 m2 at CMR, and (4) had images suitable for feature tracking analysis. These subjects were matched to healthy age- and sex-matched control subjects. CMR feature tracking analysis was performed on a ventricular short-axis stack of balanced steady-state free precession images. Measurements included LV basal and apical rotation, twist, torsion, peak systolic rates of rotation and torsion, and timing of events. Associations with LV torsion were assessed. RESULTS: A total of 60 rTOF patients (23.6 ± 7.9 years, 52% male) and 30 healthy control subjects (20.8 ± 3.1 years, 50% male) were included. Compared with healthy controls, rTOF patients had lower apical and basal rotation, twist, torsion, and systolic rotation rates, and these parameters peaked earlier in systole. The only parameters that were correlated with LV torsion were right ventricular (RV) end-systolic volume (r = - 0.28, p = 0.029) and RV ejection fraction (r = 0.26, p = 0.044). At a median of 1.0 year (IQR 0.5-1.7) following PVR, there was no significant change in LV rotational parameters versus pre-PVR despite reductions in RV volumes, RV mass, pulmonary regurgitation, and RV outflow tract obstruction. CONCLUSION: In this comprehensive study of CMR-derived LV rotational mechanics in rTOF patients, rotation, twist, and torsion were diminished compared to controls and did not improve at a median of 1 year after PVR despite favorable RV remodeling.

Online education in a hurry: Delivering pediatric graduate medical education during COVID-19.

In the setting of the coronavirus disease 2019 (COVID-19) pandemic, an emergency hospital-wide eWork policy was enacted at Boston Children's Hospital on March 16, 2020. The number of clinicians on campus was restricted to only essential personnel, guidelines limited clinical care delivery to solely non-elective patients, and strict maximums were placed on the numbers of people allowed to congregate in the same physical space. With this abrupt transition to social distancing and electronic communication, the established approach to educating graduate medical trainees became obsolete overnight. Anticipating significant impact on trainee and faculty professional and personal lives, the importance of adaptive teaching strategies was evident. This document details one approach to redesigning the clinical learning system including a description of the learners and environment, the pedagogical principles that guided the approach, and technological tools used in implementation. Additionally, available literature pertinent to this topic is explored, assessment of the work to date is presented, and suggestions are provided regarding future directions related to online graduate medical education.

Use of institutional criteria for transcatheter device closure of Fontan fenestration - Midterm outcomes.

BACKGROUND: There are no established criteria to decide suitability for Fontan fenestration closure. Our institution has the following criteria: an unobstructed Fontan pathway with no significant decompressing venovenous collaterals, baseline Fontan pressure ≤15 mmHg, baseline cardiac index ≥2 L/min/m2, and a decrease in cardiac index ≤20% with test occlusion of the fenestration. OBJECTIVE: The objective of the study was to review midterm outcomes following device closure of Fontan fenestration using institutional criteria. MATERIALS AND METHODS: A retrospective review was performed of patients who underwent catheterization with prior fenestrated Fontan procedure between May 2005 and January 2015. Patients were classified as those who underwent successful closure (A), had closure deferred due to failure to meet criteria (B), or were not referred for closure (C). RESULTS: There were 42 patients in Group A, 10 in Group B, and 150 in Group C. The mean Fontan pressure increased from 13.1 ± 2.1 to 14.5 ± 2.1mmHg in Group A and 14.6 ± 1.5 to 15.7 ± 2.2 mmHg in Group B (P = not significant). With test occlusion, cardiac index fell by 18.12% ± 15.68% in Group A and 33.75% ± 14.98% in Group B (P = 0.019). At a median of 46 month follow-up, oxygen saturation increased significantly from 85.15% ± 6.29% at baseline to 94.6% ± 4.43% (P < 0.001) in Group A but with no statistically significant difference in the rates of plastic bronchitis, protein-losing enteropathy, stroke, or heart transplantation between the three groups. CONCLUSIONS: Using institutional criteria, transcatheter device closure of Fontan fenestration was followed by significant increase in oxygen saturations and no statistically significant difference in morbidity or mortality between closure and nonclosure groups.

Impact of the superior cavopulmonary anastomosis on cerebral oxygenation.

BACKGROUND: Patients with univentricular heart disease may undergo a superior cavopulmonary anastomosis, an operative intervention that raises cerebral venous pressure and impedance to cerebral venous return. The ability of infantile cerebral autoregulation to compensate for this is not well understood. MATERIALS AND METHODS: We identified all patients undergoing a superior cavopulmonary anastomosis (cases) and compared metrics of cerebral oxygenation upon admission to the ICU with patients following repair of tetralogy of Fallot or arterial switch operation (controls). The primary endpoint was cerebral venous oxyhaemoglobin saturation measured from an internal jugular venous catheter. Other predictor variables included case-control assignment, age, weight, sex, ischemic times, arterial oxyhaemoglobin saturation, mean arterial blood pressure, and superior caval pressure. RESULTS: A total of 151 cases and 350 controls were identified. The first post-operative cerebral venous oxyhaemoglobin saturation was significantly lower following superior cavopulmonary anastomosis than in controls (44 ± 12 versus 59 ± 15%, p < 0.001), as was arterial oxyhaemoglobin saturation (81 ± 9 versus 98 ± 5%, p < 0.001). Cerebral venous oxyhaemoglobin saturation correlated poorly with superior caval pressure in both groups. When estimated by linear mixed effects model, arterial oxyhaemoglobin saturation was the primary determinant of central venous oxyhaemoglobin saturation in both groups (ß = 0.79, p = 3 × 10-14); for every 1% point increase in arterial oxyhaemoglobin saturation, there was a 0.79% point increase in venous oxyhaemoglobin saturation. In this model, no other predictors were significant, including superior caval pressure and case-control assignment. CONCLUSION: Cerebral autoregulation appears to remain intact despite acute imposition of cerebral venous hypertension following superior cavopulmonary anastomosis. Following superior cavopulmonary anastomosis, cerebral venous oxyhaemoglobin saturation is primarily determined by arterial oxyhaemoglobin saturation.

Echocardiographic Diagnosis of Anomalous Single Coronary Artery from the Pulmonary Artery: Use of Bubble Contrast Echocardiography.

Anomalous origin of a coronary artery from the pulmonary artery (PA) is a rare congenital anomaly with the most common pattern being an anomalous left coronary artery (LCA) from the pulmonary artery (ALCAPA). A very rare pattern is the anomalous origin of a single coronary artery from the pulmonary artery (ASCAPA) wherein the single coronary ostium supplies both the right and left coronary systems with profound myocardial ischemia developing once PA pressures begin to fall after birth. Previous reports of this anomaly have all been based on post-mortem findings or pre-mortem angiographic diagnosis [1-3]. Notably, these children often present in extremis due to cardiogenic shock. Institution of veno-arterial extracorporeal life support can be catastrophic as it would lead to myocardial ischemia due to PA decompression. We present here the first echocardiographic-only diagnosis of ASCAPA in a 2-month-old child with the use of bubble contrast echocardiography to help confirm the diagnosis. The patient was resuscitated from a cardiac arrest on arrival with subsequent echocardiographic-only diagnosis. Surgical repair was undertaken with administration of cardioplegia into the pulmonary root with snaring of the branch PAs, and re-implantation of the single coronary to the aorta. At 3-month follow-up, he is thriving clinically with echocardiogram showing improving-though still somewhat depressed-left ventricular function.

Pre-ECMO coagulopathy does not increase the occurrence of hemorrhage during extracorporeal support.

INTRODUCTION AND METHODS: Observational retrospective cohort study to evaluate the association between precannulation coagulopathy and the occurrence of hemorrhage during extracorporeal membrane oxygenation (ECMO) in neonatal and pediatric patients at a tertiary children's hospital. RESULTS: Of 241 patients supported with ECMO between January 2009 and December 2014, 175 (72.6%) had precannulation coagulation laboratory data and were included in the study. Of the eligible patients, 84 (48%) were identified as coagulopathic and 91 (52%) were noncoagulopathic. In the coagulopathic group, sepsis (27.3%) was the most common diagnosis leading to ECMO. Over half of the patients in both groups (55.9% of the coagulopathic and 52.7% of the noncoagulopathic group) developed hemorrhagic complications during ECMO support. The most frequent bleeding sites for both groups were the cannulation site (24%), the chest tube site (17%), and intracranial (10%). Pre-ECMO coagulopathy was not associated with higher incidence of hemorrhage during extracorporeal support (p = 0.76). CONCLUSIONS: Pre-ECMO coagulopathy was frequent in our cohort but did not increase the occurrence of hemorrhage during extracorporeal support. Although the identification of factors associated with hemorrhage is key to safely managing ECMO anticoagulation, the implication of precannulation coagulopathy seems to be minimal.

New-onset cardiac rhabdomyoma beyond infancy in a patient with tuberous sclerosis complex.

Cardiac rhabdomyomas in patients with tuberous sclerosis complex are usually detected antenatally or during infancy, with subsequent stabilisation or spontaneous regression. Development of a new cardiac rhabdomyoma beyond infancy is very rare. We report a male child who needed resection of a large rhabdomyoma in neonatal life, and then developed a new-onset rhabdomyoma at 2 years of age in a different location, needing another resection. Routine surveillance for cardiac rhabdomyomas in asymptomatic patients with tuberous sclerosis is essential.

Retrieval of endobronchial foreign bodies in children: involving the cardiac catheterization lab.

Endobronchial foreign body impaction is a common occurrence, especially in the pediatric population. Bronchoscopic techniques are the standard of care for their retrieval. However, the most distally located foreign bodies are often difficult to retrieve using these techniques. A novel approach using biplane fluoroscopy, with tools usually used for intravascular foreign body retrieval, has been recently described in adults by interventional radiologists. We are the first to report 2 cases in children using this approach for distally impacted endobronchial foreign body retrieval in the cardiac catheterization laboratory. We used a collaborative approach, using flexible bronchoscopy and fluoroscopically guided catheters to reach the foreign body. The first case involved a 16-year-old girl who presented with a 4-day history of aspiration of a staple pin, which we successfully retrieved. The second case involved a 10-year-old boy who presented with a 2-month history of aspiration of the plastic eraser cap of a mechanical pencil. We were successful in reaching the distal lobule where it was lodged. However, we were unable to grasp the foreign body because of the presence of a chronic inflammatory exudate around it owing to the subacute to chronic presentation. There were no complications in either case. Thus, a collaboration of the pulmonology and interventional cardiology teams in the cardiac catheterization laboratory represents a safe and effective alternative to bronchoscopy in the management of distally placed endobronchial foreign bodies in children. Early recognition and intervention is imperative for the successful retrieval of an endobronchial foreign body.