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.