Repair of a mixed form of supracardiac total anomalous pulmonary venous connection.

Total anomalous pulmonary venous connection is a rare congenital heart defect. We report an infant with a mixed form of supracardiac TAPVC, in whom all pulmonary veins, except the right upper, entered a pulmonary venous confluence that is connected to a vertical vein and drained into the superior vena caval-right atrial junction. Several segmental right upper pulmonary veins entered the superior vena cava, superior to the entry of the vertical vein. Surgical repair consisted of the Warden procedure combined with direct anastomosis of the vertical vein to the left atrium. Separate pulmonary venous drainage pathways decreased the risk of post-operative pulmonary venous obstruction. Our patient had an uneventful post-operative course and encouraging 2-month follow-up echocardiography. Careful follow-up is warranted to detect post-operative complications, including obstruction of the pulmonary venous and cavoatrial anastomoses.

Selective inhibition of ATPase activity during contraction alters the activation of p38 MAP kinase isoforms in skeletal muscle.

Muscle contractions strongly activate p38 MAP kinases, but the precise contraction-associated sarcoplasmic event(s) (e.g., force production, energetic demands, and/or calcium cycling) that activate these kinases are still unclear. We tested the hypothesis that during contraction the phosphorylation of p38 isoforms is sensitive to the increase in ATP demand relative to ATP supply. Energetic demands were inhibited using N-benzyl-p-toluene sulphonamide (BTS, type II actomyosin) and cyclopiazonic acid (CPA, SERCA). Extensor digitorum longus muscles from Swiss Webster mice were incubated in Ringer's solution (37°C) with or without inhibitors and then stimulated at 10 Hz for 15 min. Muscles were immediately freeze-clamped for metabolite and Western blot analysis. BTS and BTS + CPA treatment decreased force production by 85%, as measured by the tension time integral, while CPA alone potentiated force by 310%. In control muscles, contractions resulted in a 73% loss of ATP content and a concomitant sevenfold increase in IMP content, a measure of sustained energetic imbalance. BTS or CPA treatment lessened the loss of ATP, but BTS + CPA treatment completely eliminated the energetic imbalance since ATP and IMP levels were nearly equal to those of non-stimulated muscles. The independent inhibition of cytosolic ATPase activities had no effect on contraction-induced p38 MAPK phosphorylation, but combined treatment prevented the increase in phosphorylation of the γ isoform while the α/ß isoforms unaffected. These observations suggest that an energetic signal may trigger phosphorylation of the p38γ isoform and also may explain how contractions differentially activate signaling pathways.

Cardiac Fibroma with Asymptomatic Ventricular Arrhythmia in an Adolescent with Gorlin's Syndrome.

Nevoid basal cell carcinoma syndrome (NBCCS), also referred to as Gorlin's syndrome, is an autosomal dominant inherited condition that predisposes affected individuals to various tumors such as cardiac fibromas. Though technically benign, cardiac fibromas may result in malignant arrhythmias and sudden death. The pertinent literature pertaining to pediatric cases of cardiac fibromas and their clinical features were reviewed. We present the case of an asymptomatic teenage with de novo NBCCS who was diagnosed with both NBCCS and cardiac fibroma later in life. The patient was noted to have clinically significant ventricular arrhythmias that were eliminated with tumor resection. There are no established best practice guidelines for the management of cardiac fibromas in patients with NBCCS. Given the risk of sudden arrhythmic death, the presence of ventricular arrhythmias should prompt strong consideration of tumor resection.

Echocardiographic Indicators Associated with Adverse Clinical Course and Cardiac Sequelae in Multisystem Inflammatory Syndrome in Children with Coronavirus Disease 2019.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 causes significant cardiovascular involvement, which can be a determinant of clinical course and outcome. The aim of this study was to investigate whether echocardiographic measures of ventricular function were independently associated with adverse clinical course and cardiac sequelae in patients with MIS-C. METHODS: In a longitudinal observational study of 54 patients with MIS-C (mean age, 6.8 ± 4.4 years; 46% male; 56% African American), measures of ventricular function and morphometry at initial presentation, predischarge, and at a median of 3- and 10-week follow-up were retrospectively analyzed and were compared with those in 108 age- and gender-matched normal control subjects. The magnitude of strain is expressed as an absolute value. Risk stratification for adverse clinical course and outcomes were analyzed among the tertiles of clinical and echocardiographic data using analysis of variance and univariate and multivariate regression. RESULTS: Median left ventricular apical four-chamber peak longitudinal strain (LVA4LS) and left ventricular global longitudinal strain (LVGLS) at initial presentation were significantly decreased in patients with MIS-C compared with the normal cohort (16.2% and 15.1% vs 22.3% and 22.0%, respectively, P < .01). Patients in the lowest LVA4LS tertile (<13%) had significantly higher C-reactive protein and high-sensitivity troponin, need for intensive care, and need for mechanical life support as well as longer hospital length of stay compared with those in the highest tertile (>18.5%; P < .01). Initial LVA4LS and LVGLS were normal in 13 of 54 and 10 of 39 patients, respectively. There was no mortality. In multivariate regression, only LVA4LS was associated with both the need for intensive care and length of stay. At median 10-week follow-up to date, seven of 36 patients (19%) and six of 25 patients (24%) had abnormal LVA4LS and LVGLS, respectively. Initial LVA4LS < 16.2% indicated abnormal LVA4LS at follow-up with 100% sensitivity. CONCLUSION: Impaired LVGLS and LVA4LS at initial presentation independently indicate a higher risk for adverse acute clinical course and persistent subclinical left ventricular dysfunction at 10-week follow-up, suggesting that they could be applied to identify higher risk children with MIS-C.

Inhibition of cross-bridge formation has no effect on contraction-associated phosphorylation of p38 MAPK in mouse skeletal muscle.

Mitogen-activated protein kinases (MAPKs), in particular p38 MAPK, are phosphorylated in response to contractile activity, yet the mechanism for this is not understood. We tested the hypothesis that the force of contraction is responsible for p38 MAPK phosphorylation in skeletal muscle. Extensor digitorum longus (EDL) muscles isolated from adult male Swiss Webster mice were stimulated at fixed length at 10 Hz for 15 min and then subjected to Western blot analysis for the phosphorylation of p38 MAPK and ERK1/2. Contralateral muscles were fixed at resting length and were not stimulated. Stimulated muscles showed a 2.5-fold increase in phosphorylated p38 MAPK relative to nonstimulated contralateral controls, and there was no change in the phosphorylation of ERK1/2. When contractile activity was inhibited with N-benzyl-p-toluene sulfonamide (BTS), a specific inhibitor of actomyosin ATPase, force production decreased in both a time- and concentration-dependent manner. Preincubation with 25, 75, and 150 microM BTS caused 78+/-4%, 97+/-0.2%, and 99+/-0.2% inhibition in contractile force, respectively, and was stable after 30 min of treatment. Fluorescence measurements demonstrated that Ca2+ cycling was minimally affected by BTS treatment. Surprisingly, BTS did not suppress the level of p38 MAPK phosphorylation in stimulated muscles. These data do not support the view that force generation per se activates p38 MAPK and suggest that other events associated with contraction must be responsible.