To compare the clinical and laboratory findings of multisystem inflammatory syndrome in children (MIS-C), patients with Kawasaki disease (KD) and with macrophage activating syndrome due to systemic juvenile idiopathic arthritis (sJIA-MAS) on real-life data. Patients diagnosed with MIS-C, KD, and sJIA-MAS from 12 different centers in Turkey who were followed for at least 6 months were included in the study. Demographic, clinical, and laboratory findings of all patients were analyzed. A total of 154 MIS-C, 59 KD, and 31 sJIA-MAS patients were included. The median age of patients with MIS-C were higher than those with KD while lower than those with sJIA-MAS (8.2, 3, 12 years, respectively). Myalgia (39.6%), cardiac (50.6%), gastrointestinal (72.7%), and neurological (22.1%) involvements were more common in patients with MIS-C compared to others. MIS-C patients had lower levels of lymphocyte (950 vs 1700 cells/µl) and thrombocyte (173,000 vs 355,000 cells/µl) counts and higher pro-BNP (1108 vs 55 pg/ml) levels than KD. Ferritin levels were higher in patients with MIS-C compared to patients with KD while they were lower than patients with sJIA-MAS (440, 170, 10,442 ng/ml, respectively). Patients with MIS-C had a shorter duration of hospitalization than sJIA-MAS ( p = 0.02) while they required intensive care unit admission more frequently (55 vs 8 patients, p < 0.001). The median MAS/sJIA score of MIS-C patients was − 1.64 (− 5.23 to 9.68) and the median MAS/sJIA score of sJIA-MAS patients was −2.81 ([− 3.79] to [− 1.27]). MIS-C patients displayed certain differences in clinical and laboratory features when compared to KD and sJIA-MAS. Definition of the differences and similarities between MIS-C and the other intense inflammatory syndromes of childhood such as KD and MAS will help the clinicians while making timely diagnosis.

Catecholaminergic polymorphic ventricular tachycardia is a rare entity that can occur in children without cardiac disease and with a normal QT interval. It may cause syncope, convulsions, and sudden death during physical activity or emotional distress. We report the clinical features, treatment, and follow-up of 16 children with this diagnosis, emphasizing the potentially fatal nature of the disease.The mean age of patients at the onset of symptoms and at the time of diagnosis was 7.8 plus or minus 2.5 years, and 10.6 plus or minus 3.5 years, respectively. Syncope was the main complaint in 11, and 7 were treated as erroneously as having epilepsy. Diagnosis was confirmed by exercise and/or infusion of isoproterenol. Once the diagnosis was made, we started propranolol in all patients, and added verapamil if ventricular tachycardia was still inducible on a treadmill exercise test. An intracardiac defibrillator was implanted in 4 patients. Of the 16 patients, 4 died suddenly, giving a rate of mortality of 25%. In 2 of those dying suddenly, there was evidence of poor compliance to the recommended treatment. Another 2 patients had been resuscitated because of sudden cardiac arrest.Catecholaminergic polymorphic ventricular tachycardia must be considered in the differential diagnosis of syncope in children without heart disease but with a normal QT interval. Medical treatment with propranolol and verapamil may decrease the incidence of arrhythmia. Implantation of intracardiac defibrillators should be considered in those resistant to drug therapy. Delay in diagnosis, and inadequate treatment, can result in sudden cardiac death.

INTRODUCTION Prevalence of isolated nocturnal hypertension (INH) and isolated daytime hypertension (IDH) is around 10% in adults. Data in children, especially in chronic kidney disease (CKD), are lacking. The aim of this cross-sectional multicenter cohort study was to define the prevalence of INH and IDH and its association with cardiovascular morphology and function, that is, pulse wave velocity (PWV), carotid intima-media thickness (cIMT), or left ventricular mass index (LVMI) in children with CKD. METHODS Ambulatory blood pressure (BP) monitoring profiles were analyzed in 456 children with CKD stages III-V participating in the Cardiovascular Comorbidity in Children with Chronic Kidney Disease Study (64.3% males, 71.3% congenital anomaly of the kidney and urinary tract, age 12.5 ± 3.2 years, estimated glomerular filtration rate 29 ± 12 ml/min per 1.73 m). Baseline PWV, cIMT, and LVMI were compared in normotension, INH, IDH, or sustained 24-h hypertension. RESULTS Prevalence of sustained hypertension was 18.4%, of INH 13.4%, and of IDH 3.7%. PWV SDS (SD score) and cIMT SDS were significantly higher in sustained hypertension and INH, and PWV SDS was significantly higher in IDH, compared with normotension. LVMI was significantly increased in sustained hypertension, but not in INH or IDH. Determinants of INH were smallness for gestational age, older age, higher height SDS and parathyroid hormone, and shorter duration of CKD. In logistic regression analysis, day/night-time hypertension or ambulatory BP monitoring pattern (normal, INH, IDH, sustained hypertension) were independently associated with cardiovascular outcome measures: elevated night-time BP was associated with increased cIMT, PWV, and left ventricular hypertrophy; INH was associated with cIMT. CON-CLUSION INH is present in almost one out of seven children with predialysis CKD; INH and nocturnal hypertension in general are associated with alterations of arterial morphology and function.

The examiner should be aware of the existence of this rare anomaly. If echocardiographic examination shows ventricular hypertrophy and/or poor ventricular function, INVM should be considered and in order to see recesses, ventricle walls should be investigated by zooming in and comparing frame by frame.

Since many of rhythm abnormalities, including life-threatening ventricular arrhythmias, may be seen in patients with IVNC, children with IVNC should be screened for arrhythmias. An ICD may be the best treatment for some of these patients.