Decreased Stroke Volume and Venous Return in School Children with Postural Tachycardia Syndrome.

In postural tachycardia syndrome (POTS), a subtype of orthostatic intolerance, the changes in hemodynamics due to postural changes are poorly understood. We speculated that inappropriate venous return, which may occur in the upright position in patients with school-aged POTS, could be detected by echocardiography. Our prospective study was conducted with 100 POTS patients (45 boys and 55 girls), aged 13.1 ± 1.5 years and 52 age- and sex-matched healthy subjects (control). Echocardiography was performed in the supine and sitting positions. Cardiac parameters [stroke volume index, cardiac index, heart rate, and the maximum inferior vena cava diameter (max IVC)] were evaluated in addition to pulse pressure. Unlike the control subjects, POTS patients demonstrated decreased stroke volume index (P = 0.02) and max IVC (P < 0.01) irrespective of posture. The rates of max IVC change did not differ between control and POTS groups. The enrolled POTS patients were divided into two subgroups [dilatation (n = 57) and contraction (n = 43)] based on whether the change rate of max IVC was less than zero or not. The contraction group showed a significantly higher heart rate than the dilatation group with respect to posture (P = 0.03), indicating the poor response of peripheral vessels in the lower limbs only in the contraction group. In conclusion, echocardiographic assessment detected decreased stroke volume and venous return in POTS. The changes in max IVC in response to postural changes may indicate an underlying pathophysiology in POTS.

Sudden Death in Patients with a History of Kawasaki Disease under School Supervision.

We investigated the incidence of sudden death in students with a history of Kawasaki disease (KD) while under school supervision. Reports of sudden death in students with a history of KD during 1990-1999 and 2000-2009 were retrieved from the mutual aid system data. The student's grade, sex, circumstances at the time of sudden death, final diagnosis, recommended restrictions on school activities, and intensity of physical activity at the time of sudden death were investigated. There were 11 cases from 1990 to 1999 and 3 from 2000 to 2009; KD was complicated with coronary artery aneurysm (CAA) in nine and one cases, respectively. The incidence of sudden death decreased by approximately 50% for KD history and 80% for KD with CAA between the two decades; however, the difference was not statistically significant. Of the 14 cases, 12 occurred during moderate-to-strenuous exercise; the restriction on exercise for students with KD complicated with CAA was not followed in at least five cases during 1990-1999, while three cases during 2000-2009 occurred without recommended restriction. Cases of sudden cardiac death decreased during 2000-2009, compared with those during 1990-1999. Special attention is required for students with a history of KD, particularly when complicated with CAA.

Characteristics of Kawasaki Disease Patients during the COVID-19 Pandemic in Japan: A Single-Center, Observational Study.

BACKGROUND: Under the Coronavirus disease 2019 (COVID-19) pandemic, manifestations in children with Kawasaki disease (KD) are different between the Western and the Eastern countries. Particularly, there has not been a report comparing a series of KD in Japan, where KD was originally discovered and has a large number of registered cases. METHODS: We compared patients with KD under the period of the COVID-19 pandemic in Japan with the report from Italy during its reported period by a retrospective, cohort, observational study in a Japanese single center. RESULTS: Thirty-two patients with typical KD were treated during the study period, while the Italian study reported 10 patients with the signs of KD. Concerning the proof of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, none (0%) of our KD cases showed a positive result and one and no patients developed the macrophage activation syndrome (MAS) and Kawasaki disease shock syndrome (KDSS), respectively; however, eight (80%) patients in the Italian series were confirmed with SARS-CoV-2 infection. MAS and KDSS developed in six and five patients, respectively. CONCLUSIONS: Cases reported as COVID-19 pandemic-related KD in Italy showed significantly different clinical characteristics from the typical KD symptoms known in Japan. Although they show KD-like manifestations, we cannot conclude that SARS-CoV-2 has the same etiology of our 'classic' KD at the present stage.