IMPORTANCE Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM), but there is no validated algorithm to identify those at highest risk. OBJECTIVE To develop and validate an SCD risk prediction model that provides individualized risk estimates. DESIGN, SETTING, AND PARTICIPANTS A prognostic model was developed from a retrospective, multicenter, longitudinal cohort study of 1024 consecutively evaluated patients aged 16 years or younger with HCM. The study was conducted from January 1, 1970, to December 31, 2017. EXPOSURES The model was developed using preselected predictor variables (unexplained syncope, maximal left-ventricular wall thickness, left atrial diameter, left-ventricular outflow tract gradient, and nonsustained ventricular tachycardia) identified from the literature and internally validated using bootstrapping. MAIN OUTCOMES AND MEASURES A composite outcome of SCD or an equivalent event (aborted cardiac arrest, appropriate implantable cardioverter defibrillator therapy, or sustained ventricular tachycardia associated with hemodynamic compromise). RESULTS Of the 1024 patients included in the study, 699 were boys (68.3%); mean (interquartile range [IQR]) age was 11 (7-14) years. Over a median follow-up of 5.3 years (IQR, 2.6-8.3; total patient years, 5984), 89 patients (8.7%) died suddenly or had an equivalent event (annual event rate, 1.49; 95% CI, 1.15-1.92). The pediatric model was developed using preselected variables to predict the risk of SCD. The model's ability to predict risk at 5 years was validated; the C statistic was 0.69 (95% CI, 0.66-0.72), and the calibration slope was 0.98 (95% CI, 0.59-1.38). For every 10 implantable cardioverter defibrillators implanted in patients with 6% or more of a 5-year SCD risk, 1 patient may potentially be saved from SCD at 5 years. CONCLUSIONS AND RELEVANCE This new, validated risk stratification model for SCD in childhood HCM may provide individualized estimates of risk at 5 years using readily obtained clinical risk factors. External validation studies are required to demonstrate the accuracy of this model's predictions in diverse patient populations.

This paper presents a modified predictive current control strategy which allows one to have control over the spectrum of the load current. The proposed method uses a model of the system to predict the behavior of the current for each possible voltage vector generated by the inverter. For that purpose, at each sampling interval, signal predictions are evaluated using a cost function that quantifies the desired system behavior.The cost function used in this work evaluates the filtered error of the load currents. The inclusion of a filter for the load error allows one to manipulate current spectra. Thus, by designing this filter appropriately, the load spectrum can be shaped. The performance of the proposed control strategy is verified by simulation and experimental results.

Pericardial effusion (PEff) is defined by an increase in the physiological amount of fluid within the pericardial space. It can appear following different medical conditions, mainly related to inflammation and cardiac surgery. Cardiac tamponade is a critical condition that occurs after sudden and/or excessive accumulation of fluid in the pericardial space that restricts appropriate filling of the cardiac chambers disturbing normal hemodynamics and ultimately causing hypotension and cardiac arrest. It is, therefore, a life-threatening condition that must be diagnosed as soon as possible for correct treatment and management. Echocardiographic evaluation of PEff is paramount for timely and appropriate diagnosis and management. A structured echocardiographic approach including two-dimensional, M-mode, and Doppler echocardiographic evaluation assessing (i) quantity and quality of pericardial fluid, (ii) collapse of cardiac chambers, (iii) respiratory variation of the ventricular diameters, (iv) inferior vena cava collapsibility, and (v) flow patterns in atrioventricular valves should give the bedside clinician the necessary information to appropriately manage PEff. Here, we review these key echocardiographic signs that will ensure an appropriate assessment of a patient with PEff and/or cardiac tamponade.

Background During the SARS‐CoV2 pandemic, there has been increase in hyperinflammatory presentation in previously healthy children with a variety of cardiac manifestations. Our objective is to describe the cardiac manifestations found in an international cohort of 55 pediatric cases with multi‐system inflammatory syndrome (MIS‐C) during the SARS‐CoV2 pandemic. Methods and Results We reviewed data on previously healthy pediatric patients (≤18 years) with structurally normal hearts who presented at hospitals in the United States, United Kingdom, Spain and Pakistan with MIS‐C and had consultation with a pediatric cardiologist. Data collected included demographics, clinical presentation, laboratory values, electrocardiographic abnormalities, echocardiographic findings and initial therapies. A total of 55 patients presented with MIS‐C. Thirty‐five patients (64%) had evidence of decreased left ventricular function, 17 (31%) had valvulitis, 12 (22%) with pericardial effusion and 11 (20%) with coronary abnormalities. Twenty‐seven (49%) required ICU admission and 24 (44%) had evidence of shock. Eleven patients (20%) fulfilled complete Kawasaki disease criteria and had lower NT pro‐BNP, D‐dimer and ferritin levels compared with those who did not fulfill criteria. Electrophysiologic abnormalities occurred in 6 patients and included complete atrioventricular (AV) block, transient AV block and ventricular tachycardia. Conclusions We describe the first international cohort of pediatric patients with MIS‐C during the SARS‐CoV2 pandemic with a range of cardiac manifestations. This paper brings awareness and alertness to the global medical community to recognize these children during the pandemic and understand the need for early cardiology evaluation and follow‐up.

Short QT syndrome is a highly malignant inherited cardiac disease characterized by ventricular tachyarrhythmias leading to syncope and sudden cardiac death. It is responsible of lethal episodes in young people, mainly infants. International guidelines establish diagnostic criteria with the presence of a QTc ≤ 340 ms in the electrocardiogram despite clinical diagnostic values remain controversial. In last years, clinical diagnosis, risk stratification as well as preventive therapies have been improved due to identification of pathophysiological mechanisms. The only effective option is implantation of a defibrillator despite Quinidine may be at times an effective option. Currently, a limited number of rare variants have been identified in seven genes, which account for nearly 20–30% of families. However, some of these variants are associated with phenotypes showing a shorter QT interval but no conclusive diagnosis of Short QT syndrome. Therefore, an exhaustive interpretation of each variant and a close genotype-phenotype correlation is necessary before clinical translation. Here, we review the main clinical and genetic hallmarks of this rare entity.

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BackgroundSudden unexplained death may be the first manifestation of an unknown inherited cardiac disease. Current genetic technologies may enable the unraveling of an etiology and the identification of relatives at risk. The aim of our study was to define the etiology of natural deaths, younger than 50 years of age, and to investigate whether genetic defects associated with cardiac diseases could provide a potential etiology for the unexplained cases.Methods and FindingsOur cohort included a total of 789 consecutive cases (77.19% males) <50 years old (average 38.6±12.2 years old) who died suddenly from non-violent causes. A comprehensive autopsy was performed according to current forensic guidelines. During autopsy a cause of death was identified in most cases (81.1%), mainly due to cardiac alterations (56.87%). In unexplained cases, genetic analysis of the main genes associated with sudden cardiac death was performed using Next Generation Sequencing technology. Genetic analysis was performed in suspected inherited diseases (cardiomyopathy) and in unexplained death, with identification of potentially pathogenic variants in nearly 50% and 40% of samples, respectively.ConclusionsCardiac disease is the most important cause of sudden death, especially after the age of 40. Close to 10% of cases may remain unexplained after a complete autopsy investigation. Molecular autopsy may provide an explanation for a significant part of these unexplained cases. Identification of genetic variations enables genetic counseling and undertaking of preventive measures in relatives at risk.

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