Association Between High Sensitivity Troponin Levels Following Pediatric Orthotopic Heart Transplantation and Intensive Care Unit Resource Utilization.

The utility of troponin levels, including high sensitivity troponin T (hs-TnT), after orthotopic heart transplant (OHT) is controversial. Conflicting data exist regarding its use as a marker of acute rejection. Few studies have examined possible associations of hs-TnT levels immediately after OHT with metrics of intensive care unit (ICU) resource utilization or risk of acute rejection. We performed a retrospective cohort chart review including all OHT recipients < 20 years of age at our center between June 2019 and December 2022. Patients were divided into two groups based on supra- or sub-median initial hs-TnT levels (median 3462.5 ng/L). Primary outcome was days requiring ICU-level care, secondary outcomes included days intubated, days requiring positive pressure ventilation (PPV), days on inotropic medications, actual ICU length of stay, Vasoactive Inotrope Scores (VIS) on postoperative days (POD) 0 through 7, and acute rejection at 30 days and one year after OHT. Patients with higher hs-TnT required ICU level care for longer [13.5 (10-17.5) vs. 9.5 (8-12) days, p = 0.01] and spent more days intubated [6 (4-7) vs. 3 (3-5) days, p < 0.001], on PPV [9 (6-15) vs. 6 (5-8.5) days, p = 0.02], and on inotropes [11 (9-14) vs. 8 (7-11) days, p = 0.025]. VIS was only different between groups on POD7 [5 (3-7) vs. 3 (0-5), p = 0.04]. There was no difference in rejection between the groups. Higher hs-TnT immediately following pediatric OHT may predict higher ICU resource utilization, despite no difference in VIS, although it does not predict acute rejection in the first year after OHT.

Trends in cardiac CT utilization for patients with pediatric and congenital heart disease: A multicenter survey study.

BACKGROUND: The use of cardiac CT (CCT) has increased dramatically in recent years among patients with pediatric and congenital heart disease (CHD), but little is known about trends and practice pattern variation in CCT utilization for this population among centers. METHODS: A 21-item survey was created to assess CCT utilization in the pediatric/CHD population in calendar years 2011 and 2021. The survey was sent to all non-invasive cardiac imaging directors of pediatric cardiology centers in North America in September 2022. RESULTS: Forty-one centers completed the survey. In 2021, 98% of centers performed CCT in pediatric and CHD patients (vs. 73% in 2011), and 61% of centers performed >100 CCTs annually (vs. 5% in 2011). While 62% of centers in 2021 utilized dual-source technology for high-pitch helical acquisition, 15% of centers reported primarily performing CCT on a 64-slice scanner. Anesthesia utilization, use of medications for heart rate control, and type of subspecialty training for physicians interpreting CCT varied widely among centers. 50% of centers reported barriers to CCT performance, with the most commonly cited concerns being radiation exposure, the need for anesthesia, and limited CT scan staffing or machine access. 37% (11/30) of centers with a pediatric cardiology fellowship program offer no clinical or didactic CCT training for categorical fellows. CONCLUSION: While CCT usage in the CHD/pediatric population has risen significantly in the past decade, there is broad center variability in CCT acquisition techniques, staffing, workflow, and utilization. Potential areas for improvement include expanding CT scanner access and staffing, formal CCT education for pediatric cardiology fellows, and increasing utilization of existing technological advances.

Oral Albuterol Treatment in Three Pediatric Patients with Bradycardia: A Novel Therapy.

Clinically significant bradycardia is an uncommon problem in children, but one that can cause significant morbidity and sometimes necessitates implantation of a pacemaker. The most common causes of bradycardia are complete heart block (CHB), which can be congenital or acquired, and sinus node dysfunction, which is rare in children with structurally normal hearts. Pacemaker is indicated as therapy for the majority of children with CHB, and while early mortality is lower in postnatally diagnosed CHB than in fetal CHB, it is still up to 16%. In young children, less invasive transvenous pacemaker systems can be technically challenging to place and carry a high risk of complications, often necessitating surgical epicardial pacemaker placement, which usually entails a median sternotomy. We report three cases of pediatric patients referred for pacemaker implantation for different types of bradycardia, treated at our institution with oral albuterol with therapeutic results that avoided the need for surgical pacemaker implantation at that time.

Tricuspid Valve Endocarditis in Four Patients with Unrepaired Restrictive Perimembranous Ventricular Septal Defects.

Congenital heart disease (CHD) is the most common predisposing factor for pediatric infective endocarditis (IE). Although patients with unrepaired ventricular septal defects (VSDs) are at greater risk of IE than those without CHD, the American Heart Association (AHA) considers VSDs to be relatively low risk and therefore does not recommend antibiotic prophylaxis against IE. Even among patients with VSDs who develop IE, current AHA and European Society for Cardiology (ESC) guidelines do not recommend surgical VSD closure, despite the potential for a second IE event. We present a case series of four children with small, restrictive, perimembranous VSDs who developed tricuspid valve (TV) IE. All four experienced delayed diagnosis and secondary complications, including three with septic pulmonary emboli. All four patients ultimately underwent surgical VSD closure. These cases highlight the importance of recognizing IE as a possible cause of prolonged fever in children, even among those with even 'low-risk' CHD. The cases also draw attention to the potential benefits of VSD closure in patients who develop IE.

Aortic Root Dilation in Patients with 22q11.2 Deletion Syndrome Without Intracardiac Anomalies.

Aortic root dilation (ARD) has been reported in patients with 22q11.2 deletion syndrome (22q11.2DS) with and without congenital heart defects (CHDs). However, the long-term implications of isolated ARD in 22q11.2DS remain undefined. In this study, we measured aortic root size and estimated the probability of changing between normal aortic root size and ARD during follow up to understand the prevalence, longitudinal course, and clinical risk factors for ARD in patients with 22q11.2DS without intracardiac CHDs. Aortic root size was measured in 251 patients with 432 studies. Forty-one patients (16.3%) had ARD on at least one echocardiogram and the cohort sinus Z-score was increased on the last echocardiogram [mean (1.09, SD 1.24) and median (1.20, min - 1.90 and max 5.40)]. Transition probability analysis showed that 8.1% of patients developed ARD and 45.4% of patients with ARD reverted to normal at the next echocardiogram. The risk of ARD over time was significantly associated with male sex (OR 3.06, 95% CI 1.41-6.65; p = 0.004), but not with age or presence of an aortic arch anomaly. Compared to a sinus Z-score ≥ 2, initial Z-score < 2 was associated with 14.3 times lower risk of developing sinus Z-score ≥ 3 at follow up. Sinus Z-score overall decreased by age, and males had a higher Z-score than females (ß = 0.72, SE = 0.14, p < 0.001). Though only a few patients had a Z-score > 4, and patients with initial Z-scores < 2 seem unlikely to develop clinically significant disease, screening practices remain incompletely defined such that periodic evaluation appears warranted.

Cardiac evaluation of patients with 22q11.2 duplication syndrome.

The 22q11.2 duplication syndrome (22q11.2DupS) is characterized by phenotypic heterogeneity, from seemingly asymptomatic to severely affected patients. Our study sought to detail the cardiac phenotype associated with 22q11.2DupS, the prevalence of aortic arch anomalies and aortic root dilation in 22q11.2DupS, and to assess how frequently new congenital heart disease (CHD) is diagnosed at outpatient cardiac evaluation following genetic diagnosis. In our cohort of 85 patients, 20.0% had CHD, with a wide range of phenotypes. Sixty-eight patients had complete cardiac evaluations detailing aortic arch sidedness and branching pattern, of which 5 (7.4%) had an aortic arch anomaly, all of whom had concurrent intracardiac CHD. Of 53 patients without CHD who had complete cardiac evaluations, only 3 (5.7%) had evidence of aortic root dilation. Of 46 patients who underwent outpatient cardiac evaluation following diagnosis of 22q11.2DupS, only one (2.2%) was found to have CHD, an isolated bicuspid aortic valve without stenosis. Therefore, the CHD phenotype in 22q11.2DupS, when present, is heterogeneous. Aortic arch anomalies are uncommon, and no patient in our cohort had one in isolation. Isolated aortic root dilation is also uncommon. Finally, outpatient cardiac evaluation following genetic diagnosis without previously known CHD infrequently identified minor cardiac malformations.

Flank pseudohernia following posterior rib fracture: a case report.

BACKGROUND: A pseudohernia is an abdominal wall bulge that may be mistaken for a hernia but that lacks the disruption of the abdominal wall that characterizes a hernia. Thus, the natural history and treatment of this condition differ from those of a hernia. This is the first report of a pseudohernia due to cough-associated rib fracture. CASE PRESENTATION: A case of pseudohernia due to fractures of the 10th and 11th ribs in a 68-year-old white woman is presented. The patient suffered from a major coughing episode 1 year prior to her presentation, after which she noted a progressively enlarging bulge in her left flank. Computed tomography demonstrated a bulge in the abdominal wall containing bowel and spleen but with all muscle and fascial layers intact; in addition, lateral 10th rib and posterior 11th rib fractures were noted. CONCLUSIONS: As there was no defect in muscle or fascia, we diagnosed a pseudohernia, likely due to a denervation injury from the fractured ribs. Symptomatic treatment was recommended, including wearing a corset and referral to a pain management clinic. Symptomatic treatment is thought to be the mainstay of therapy for pseudohernias, as surgical intervention is unlikely to be of benefit.

Color-detection thresholds in rhesus macaque monkeys and humans.

Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. All subjects were tested on an identical apparatus with a four-alternative forced-choice task. Targets were 2° square, centered 2° from fixation, embedded in luminance noise. Across all subjects, the change in detection thresholds from initial testing to plateau performance ("learning") was similar for +L − M (red) colors and +M − L (bluish-green) colors. But the extent of learning was higher for +S (lavender) than for −S (yellow-lime); moreover, at plateau performance, the cone contrast at the detection threshold was higher for +S than for −S. These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L − M mechanism.

Identification of binding partners for the cytoplasmic loop of connexin43: a novel interaction with ß-tubulin.

Connexin43 (Cx43), a component of gap junctions, has a relatively large carboxy-terminal region with multiple proteomic interactions. Proteomic interactions with its cytoplasmic loop, however, are poorly defined. The goal of this study is to examine proteomic interactions involving the cytoplasmic loop (CL) of Cx43. The authors utilized various techniques, including glutathione-S-transferase (GST) pull-down, immunoblot analysis, two-dimensional (2D) gel electrophoresis, and mass spectrometry, to elucidate binding partners for Cx43-CL. The authors identified novel interactions with Cx43-CL involving α- and ß-tubulin, myelin basic protein, and Purα. Because tubulin interacts with the C-terminus of Cx43 (Cx43-CT), the authors further investigated the nature of the interaction between ß-tubulin and Cx43-CL. ß-Tubulin binds with the full length of Cx43-CL with approximately one-fifth the affinity of the interaction between Cx43-CT and ß-tubulin. This study demonstrates novel proteomic interactions involving Cx43-CL that may lead to a more complete understanding of trafficking and gating of gap junction channels.