Spatial structure and composition of invertebrates in high altitude rivers of the central Andes (Olaroz Salar, Argentina).

This study aimed to examine the spatial variation in sets of micro and macroinvertebrates and to detect how physicochemical and environmental variables affect community structures in high Andean rivers. Six sites were sampled in three rivers of the Argentinian plateau, in altitudes between 3900-4400 masl during the dry season (May-October 2017). The variables that affected the structure of the micro and macroinvertebrate communities were: altitude, conductivity, turbidity, water temperature, hardness, oxygen, and lead. Sites with high levels of arsenic, lead and boron were identified. Assemblages of species common to high Andean courses were recorded on a north-south axis. The registered community structure has similarities with High Andean streams of Bolivia and rivers of the Catamarca plateau, increasing the differences in composition and assemblages towards the south (Mendoza and Patagonian Andes). Diptera was the best represented with Orthocladiinae and Podonominae, reaching better representativeness at higher altitudes. Together with them, Austrelmis, Hydracarina, Hirudinea, Nais, Hyalella constitute the dominant group. There is a trend towards a decrease in the richness of species with respect to altitude, related to the proximity of the Salar and the increase in conductivity, carbonates and hardness.

Status of Multidisciplinary Collaboration in Neonatal Cardiac Care in the United States.

While outcomes for neonates with congenital heart disease have improved, it is apparent that substantial variability exists among centers with regard to the multidisciplinary approach to care for this medically fragile patient population. We endeavored to understand the landscape of neonatal cardiac care in the United States. A survey was distributed to physicians who provide neonatal cardiac care in the United States regarding (1) collaborative efforts in care of neonates with congenital heart disease (CHD); (2) access to neonatal cardiac training; and (3) barriers to the implementation of protocols for neonatal cardiac care. Responses were collected from 10/2018 to 6/2019. We received responses from 172 of 608 physicians (28% response rate) from 89 centers. When compared to responses received from physicians at low-volume centers (< 300 annual bypass cases), those at high-volume centers reported more involvement from the neurodevelopmental teams (58% vs. 29%; P = 0.012) and a standardized transition to outpatient care (68% vs. 52%; P = 0.038). While a majority of cardiothoracic surgery and anesthesiology respondents reported multidisciplinary involvement, less than half of cardiology and neonatology supported this statement. The most commonly reported obstacles to multidisciplinary engagement were culture (61.6%) and logistics (47.1%). Having a standardized neonatal cardiac curriculum for neonatal fellows was positively associated with the perception that multidisciplinary collaboration was "always" in place (53% vs. 40%; P = 0.09). There is considerable variation among centers in regard to personnel involved in neonatal cardiac care, related education, and perceived multidisciplinary collaboration among team members. The survey findings suggest the need to establish concrete standards for neonatal cardiac surgical programs, with ongoing quality improvement processes.

Loss of Consciousness in the Young Child.

In the very young child (less than eight years of age), transient loss of consciousness represents a diagnostic and management dilemma for clinicians. While most commonly benign, syncope may be due to cardiac dysfunction which can be life-threatening. It can be secondary to an underlying ion channelopathy, cardiac inflammation, cardiac ischemia, congenital heart disease, cardiomyopathy, or pulmonary hypertension. Patients with genetic disorders require careful evaluation for a cardiac cause of syncope. Among the noncardiac causes, vasovagal syncope is the most common etiology. Breath-holding spells are commonly seen in this age group. Other causes of transient loss of consciousness include seizures, neurovascular pathology, head trauma, psychogenic pseudosyncope, and factitious disorder imposed on another and other forms of child abuse. A detailed social, present, past medical, and family medical history is important when evaluating loss of consciousness in the very young. Concerning characteristics of syncope include lack of prodromal symptoms, no preceding postural changes or occurring in a supine position, after exertion or a loud noise. A family history of sudden unexplained death, ion channelopathy, cardiomyopathy, or congenital deafness merits further evaluation. Due to inherent challenges in diagnosis at this age, often there is a lower threshold for referral to a specialist.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association.

BACKGROUND: Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation. PURPOSE: The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined. CONCLUSIONS: The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children. IMPLICATIONS: Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Epicardial ablation of tachyarrhythmia in children: Experience at two academic centers.

BACKGROUND: Experience with percutaneous epicardial ablation of tachyarrhythmia in pediatrics is limited. This case series addresses the feasibility, safety, and complications of the procedure in children. METHODS: A total of nine patients underwent 10 epicardial ablation procedures from 2002 to 2013 at two academic centers. Activation mapping was performed in all cases, and electroanatomic map was utilized in nine of the 10 procedures. Patients had undergone one to three failed endocardial catheter ablations in addition to medical management, and all had symptoms, a high-risk accessory pathway (AP), aborted cardiac arrest with Wolff-Parkinson-White syndrome (WPW), or ventricular dysfunction. A standard epicardial approach was used for access in all cases, using a 7- or 8- Fr sheath. Epicardial ablation modality was radiofrequency (RF) in seven, cryoablation (CRYO) in one, and CRYO plus RF in one. RESULTS: Median age was 14 (range 8-19) years. INDICATIONS: drug refractory ectopic atrial tachycardia (one), ventricular tachycardia (VT) (five), high-risk AP (two), and aborted cardiac arrest from WPW - (one). Epicardial ablation was not performed in one case despite access due to an inability to maneuver the catheter around a former pericardial scar. VT foci included the right ventricular outflow tract septum, high posterior left ventricle (LV), LV outflow tract, postero-basal LV, and scar from previous rhabdomyoma surgery. WPW foci were in the area of the posterior septum and coronary sinus in all three cases. Overall procedural success was 70% (7/10), with epicardial ablation success in five and endocardial ablation success after epicardial mapping in two. The VT focus was close to the left anterior descending coronary artery in one of the unsuccessful cases in which both RF and CRYO were used. There was one recurrence after a successful epicardial VT ablation, which was managed with a second successful epicardial procedure. There were no other recurrences at more than 1 year of follow-up. Complications were minimal, with one case of inadvertent pleural access requiring no specific therapy. No pericarditis or effusion was seen in any of the patients who underwent epicardial ablation. CONCLUSION: Epicardial ablation in pediatric patients can be performed with low complications and acceptable success. It can be considered for a spectrum of tachycardia mechanisms after failed endocardial ablation attempts and suspected epicardial foci. Success and recurrence may be related to foci in proximity to the epicardial coronaries, pericardial scar, or a distant location from the closest epicardial location. Repeat procedures may be necessary.

Melody pulmonary valve bacterial endocarditis: experience in four pediatric patients and a review of the literature.

OBJECTIVES: The objectives of this manuscript are two-fold: (a) to describe the clinical characteristics and management of four pediatric patients with bacterial endocarditis (BE) after Melody pulmonary valve implantation (MPVI); and (b) to review the literature regarding Melody pulmonary valve endocarditis. BACKGROUND: There are several reports of BE following MPVI. The clinical course, BE management and outcome remain poorly defined. METHODS: This is a multi-center report of four pediatric patients with repaired tetralogy of Fallot (TOF) and BE after MPVI. Clinical presentation, echocardiogram findings, infecting organism, BE management, and follow-up assessment are described. We review available literature on Melody pulmonary valve endocarditis and discuss the prognosis and challenges in the management of these patients. RESULTS: Of our four BE patients, two had documented vegetations and three showed worsening pulmonary stenosis. All patients remain asymptomatic after medical treatment (4) and surgical prosthesis replacement (3) at follow-up of 17 to 40 months. Analysis of published data shows that over half of patients undergo bioprosthesis explantation and that there is a 13% overall mortality. The most common BE pathogens are the Staphylococcus and Streptococcus species. CONCLUSIONS: Our case series of four pediatric patients with repaired TOF confirms a risk for BE after MPVI. A high index of suspicion for BE should be observed after MPVI. All patients should be advised to follow lifelong BE prophylaxis after MPVI. In case of BE, surgery should be considered for valve dysfunction or no clinical improvement in spite of medical treatment.

Short QT syndrome manifesting with neonatal atrial fibrillation and bradycardia.

OBJECTIVES: Atrial fibrillation (AF) is rare during childhood and usually associated with other cardiovascular pathology. In lone AF, the ventricular response rate is usually rapid. We sought to describe a subset of children who present with early-onset AF and a slow ventricular response rate who were found to have the short QT syndrome (SQTS). METHODS: Using a MEDLINE/PubMed search, children with AF, a structurally normal heart and bradycardia were identified. Demographics, clinical presentation, electrocardiographic (ECG) findings, electrophysiologic testing, genetic analysis and follow-up assessment were collected on each child for analysis. RESULTS: Four children were identified in the literature and combined with 2 other children followed by the authors. All had a short QT interval and those who were tested were found to have a gain-of-function mutation in the KCNQ1 gene. CONCLUSIONS: We describe a subclass of children with SQTS who present with AF and a slow ventricular response. Medical therapy has not been effective in maintaining sinus rhythm. The long-term outcome remains unknown for these children. This condition may present in utero as persistent bradycardia with postnatal ECG showing a very short QT interval.

Isolated Coarctation of the Aorta: Current Concepts and Perspectives.

Current management of isolated CoA, localized narrowing of the aortic arch in the absence of other congenital heart disease, is a success story with improved prenatal diagnosis, high survival and improved understanding of long-term complication. Isolated CoA has heterogenous presentations, complex etiologic mechanisms, and progressive pathophysiologic changes that influence outcome. End-to-end or extended end-to-end anastomosis are the favored surgical approaches for isolated CoA in infants and transcatheter intervention is favored for children and adults. Primary stent placement is the procedure of choice in larger children and adults. Most adults with treated isolated CoA thrive, have normal daily activities, and undergo successful childbirth. Fetal echocardiography is the cornerstone of prenatal counseling and genetic testing is recommended. Advanced 3D imaging identifies aortic complications and myocardial dysfunction and guides individualized therapies including re-intervention. Adult CHD program enrollment is recommended. Longer follow-up data are needed to determine the frequency and severity of aneurysm formation, myocardial dysfunction, and whether childhood lifestyle modifications reduce late-onset complications.

Short QT syndrome in a pediatric patient.

Short QT syndrome (SQTS) is a recently described genetic syndrome characterized by abnormally brisk ventricular repolarization. Similar to long QT syndrome, SQTS might result in ventricular arrhythmias, syncope, and sudden death. The clinical diagnosis of SQTS is supported by the finding of an abnormally short QT interval on the resting electrocardiogram in combination with a suggestive clinical or family history. To date, few pediatric cases have been reported and the ideal therapy is unknown. We report a teenage boy who suffered a witnessed ventricular fibrillation arrest and was subsequently diagnosed with SQTS. Additional data from nine other pediatric patients diagnosed with SQTS are presented.

Intrahepatic cholangiocarcinoma after Fontan procedure in an adult with visceral heterotaxy.

Hepatic dysfunction, including development of hepatocellular carcinoma and other liver lesions has been increasingly reported following Fontan procedure for congenital heart disease. We report a unique case of intrahepatic cholangiocarcinoma 28 years after a Fontan procedure in a 31year old female with heterotaxy syndrome. The subcapsular mass-forming tumor was composed of poorly differentiated tumor cells arranged in small vague glandular or slit-lumen nests, and focally fused or anastomosing large trabecular patterns within the prominent fibrotic stroma. The tumor cells with immunoreactivity to CK7, CK19, Cam5.2, COX2, EMA, BCL-2, MOC-31 and AE1/AE3, supported a diagnosis of intrahepatic cholangiocarcinoma. Focal atypical ductular proliferation within the background liver may represent a precursor lesion to this tumor. Dysmorphic cilia observed by electron microscopy examination in the background liver may suggest cholangiociliopathy in heterotaxy. MYST3 mutation at Q1388H detected in intrahepatic cholangiocarcinoma is reported for the first time.

Development of quality metrics for ambulatory care in pediatric patients with tetralogy of Fallot.

OBJECTIVE: The objective of this study was to develop quality metrics (QMs) relating to the ambulatory care of children after complete repair of tetralogy of Fallot (TOF). DESIGN: A workgroup team (WT) of pediatric cardiologists with expertise in all aspects of ambulatory cardiac management was formed at the request of the American College of Cardiology (ACC) and the Adult Congenital and Pediatric Cardiology Council (ACPC), to review published guidelines and consensus data relating to the ambulatory care of repaired TOF patients under the age of 18 years. A set of quality metrics (QMs) was proposed by the WT. The metrics went through a two-step evaluation process. In the first step, the RAND-UCLA modified Delphi methodology was employed and the metrics were voted on feasibility and validity by an expert panel. In the second step, QMs were put through an "open comments" process where feedback was provided by the ACPC members. The final QMs were approved by the ACPC council. RESULTS: The TOF WT formulated 9 QMs of which only 6 were submitted to the expert panel; 3 QMs passed the modified RAND-UCLA and went through the "open comments" process. Based on the feedback through the open comment process, only 1 metric was finally approved by the ACPC council. CONCLUSIONS: The ACPC Council was able to develop QM for ambulatory care of children with repaired TOF. These patients should have documented genetic testing for 22q11.2 deletion. However, lack of evidence in the literature made it a challenge to formulate other evidence-based QMs.

Development of Quality Metrics in Ambulatory Pediatric Cardiology.

The American College of Cardiology Adult Congenital and Pediatric Cardiology (ACPC) Section had attempted to create quality metrics (QM) for ambulatory pediatric practice, but limited evidence made the process difficult. The ACPC sought to develop QMs for ambulatory pediatric cardiology practice. Five areas of interest were identified, and QMs were developed in a 2-step review process. In the first step, an expert panel, using the modified RAND-UCLA methodology, rated each QM for feasibility and validity. The second step sought input from ACPC Section members; final approval was by a vote of the ACPC Council. Work groups proposed a total of 44 QMs. Thirty-one metrics passed the RAND process and, after the open comment period, the ACPC council approved 18 metrics. The project resulted in successful development of QMs in ambulatory pediatric cardiology for a range of ambulatory domains.

Hyperhomocysteinemia Alters Sinoatrial and Atrioventricular Nodal Function: Role of Magnesium in Attenuating These Effects.

Patients with hyperhomocysteinemia (HHcy), or elevated plasma homocysteine (Hcy), are at higher risk of developing arrhythmias and sudden cardiac death; however, the mechanisms are unknown. In this study, the effects of HHcy on sinus node function, atrioventricular conduction, and ventricular vulnerability were investigated by electrophysiological (EP) analysis, and the role of magnesium (Mg(2+)), an endogenous N-methyl-D-aspartate (NMDA) receptor antagonist, in attenuating EP changes due to HHcy was explored. Wild-type mice (WT) and mice receiving Hcy in the drinking water for 12 weeks (DW) were subjected to electrocardiographic and EP studies. DW compared to WT had significantly shorter RR, PR, QT, and HV intervals, corrected sinus node recovery times (CSNRT), Wenckebach periodicity (WP), atrioventricular nodal effective refractory periods (AVNERP), and right ventricular effective refractory periods (RVERP). To examine the role of Mg(2+) in mitigating conduction changes in HHcy, WT, DW, and heterozygous cystathionine-ß-synthase knockout mice (CBS (+/-) ) were subjected to repeat EP studies before and after administration of low-dose magnesium sulfate (20 mg/kg). Mg(2+) had no effect on EP variables in WT, but significantly slowed CSNRT, WP, and AVNERP in DW, as well as WP and AVNERP in CBS (+/-) . These findings suggest that ionic channels modulated by Mg(2+) may contribute to HHcy-induced conduction abnormalities.

Aortic thrombus after coil occlusion of a type E patent ductus arteriosus.

A 5-year-old girl was referred to our institution for closure of a silent patent ductus arteriosus. Cardiac catheterization revealed a tiny-to-small patent ductus arteriosus of the elongated, conical type (Type E). Coil occlusion was performed with a Gianturco coil, 0.035-4 cm(-3) mm. A follow-up echocardiogram showed a very small residual ductal shunt and a moderate-sized thrombus at the aortic end of the ductus arteriosus. The patient remained asymptomatic.

D-transposition of the great arteries: the current era of the arterial switch operation.

This paper aims to update clinicians on "hot topics" in the management of patients with D-loop transposition of the great arteries (D-TGA) in the current surgical era. The arterial switch operation (ASO) has replaced atrial switch procedures for D-TGA, and 90% of patients now reach adulthood. The Adult Congenital and Pediatric Cardiology Council of the American College of Cardiology assembled a team of experts to summarize current knowledge on genetics, pre-natal diagnosis, surgical timing, balloon atrial septostomy, prostaglandin E1 therapy, intraoperative techniques, imaging, coronary obstruction, arrhythmias, sudden death, neoaortic regurgitation and dilation, neurodevelopmental (ND) issues, and lifelong care of D-TGA patients. In simple D-TGA: 1) familial recurrence risk is low; 2) children diagnosed pre-natally have improved cognitive skills compared with those diagnosed post-natally; 3) echocardiography helps to identify risk factors; 4) routine use of BAS and prostaglandin E1 may not be indicated in all cases; 5) early ASO improves outcomes and reduces costs with a low mortality; 6) single or intramural coronary arteries remain risk factors; 7) post-ASO arrhythmias and cardiac dysfunction should raise suspicion of coronary insufficiency; 8) coronary insufficiency and arrhythmias are rare but are associated with sudden death; 9) early- and late-onset ND abnormalities are common; 10) aortic regurgitation and aortic root dilation are well tolerated; and 11) the aging ASO patient may benefit from "exercise-prescription" rather than restriction. Significant strides have been made in understanding risk factors for cardiac, ND, and other important clinical outcomes after ASO.

Long-term follow-up of a pediatric cohort with short QT syndrome.

OBJECTIVES: The purpose of this study was to define the clinical characteristics and long-term follow-up of pediatric patients with short QT syndrome (SQTS). BACKGROUND: SQTS is associated with sudden cardiac death. The clinical characteristics and long-term prognosis in young patients have not been reported. METHODS: This was an international case series involving 15 centers. Patients were analyzed for electrocardiography characteristics, genotype, clinical events, Gollob score, and efficacy of medical or defibrillator (implantable cardioverter-defibrillator [ICD]) therapy. To assess the possible prognostic value of the Gollob score, we devised a modified Gollob score that excluded clinical events from the original score. RESULTS: Twenty-five patients 21 years of age or younger (84% males, median age: 15 years, interquartile range: 9 to 18 years) were followed up for 5.9 years (interquartile range: 4 to 7.1 years). Median corrected QT interval for heart rate was 312 ms (range: 194 to 355 ms). Symptoms occurred in 14 (56%) of 25 patients and included aborted sudden cardiac death in 6 patients (24%) and syncope in 4 patients (16%). Arrhythmias were common and included atrial fibrillation (n = 4), ventricular fibrillation (n = 6), supraventricular tachycardia (n = 1), and polymorphic ventricular tachycardia (n = 1). Sixteen patients (84%) had a familial or personal history of cardiac arrest. A gene mutation associated with SQTS was identified in 5 (24%) of 21 probands. Symptomatic patients had a higher median modified Gollob score (excluding points for clinical events) compared with asymptomatic patients (5 vs. 4, p = 0.044). Ten patients received medical treatment, mainly with quinidine. Eleven of 25 index cases underwent ICD implantation. Two patients had appropriate ICD shocks. Inappropriate ICD shocks were observed in 64% of patients. CONCLUSIONS: SQTS is associated with aborted sudden cardiac death among the pediatric population. Asymptomatic patients with a Gollob score of <5 remained event free, except for an isolated episode of supraventricular tachycardia, over an average 6-year follow-up. A higher modified Gollob score of 5 or more was associated with the likelihood of clinical events. Young SQTS patients have a high rate of inappropriate ICD shocks.

Hot topics in tetralogy of Fallot.

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. We explore "hot topics" to highlight areas of emerging science for clinicians and scientists in moving toward a better understanding of the long-term management of patients with repaired TOF. From a genetic perspective, the etiology of TOF is multifactorial, with a familial recurrence risk of 3%. Cardiac magnetic resonance is the gold standard assessment tool based on its superior imaging of the right ventricular (RV) outflow tract, pulmonary arteries, aorta, and aortopulmonary collaterals, and on its ability to quantify biventricular size and function, pulmonary regurgitation (PR), and myocardial viability. Atrial re-entrant tachycardia will develop in more than 30% of patients, and high-grade ventricular arrhythmias will be seen in about 10% of patients. The overall incidence of sudden cardiac death is estimated at 0.2%/yr. Risk stratification, even with electrophysiologic testing and cardiac magnetic resonance, remains imperfect. Drug therapy has largely been abandoned, and defibrillator placement, despite its high risks for complications and inappropriate discharges, is often recommended for patients at higher risk. Definitive information about optimal surgical strategies for primary repair to preserve RV function, reduce arrhythmia, and optimize functional status is lacking. Post-operative lesions are often amenable to transcatheter intervention. In selected cases, PR may be treated with transcatheter valve insertion. Ongoing surveillance of RV function is a crucial component of clinical assessment. Except for resynchronization with biventricular pacing, no medical therapies have been shown to be effective after RV dysfunction occurs. In patients with significant PR with RV dilation, optimal timing of pulmonary valve replacement remains uncertain, although accepted criteria are emerging.

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.