Baseline heart rate variability in children and adolescents with vasovagal syncope.

Purpose: This study aimed to evaluate the autonomic imbalance in syncope by comparing the baseline heart rate variability (HRV) between healthy children and those with vasovagal syncope.

Methods: To characterize the autonomic profile in children experiencing vasovagal syncope, we evaluated the HRV of 23 patients aged 7-18 years and 20 healthy children. These children were divided into preadolescent (<12 years) and adolescent groups.

Establishment of secondary iron overloaded mouse model: evaluation of cardiac function and analysis according to iron concentration.

Periodic blood transfusion can lead to secondary iron overload in patients with hematologic and oncologic diseases. Iron overload can result in iron deposition in heart tissue, which decreases cardiac function and can ultimately lead to death due to dilated cardiomyopathy and cardiac failure. In this study, we established murine model of secondary iron overload, studied the changes in cardiac function with echocardiography, and examined the histopathologic changes.