Cardiac abnormalities in children with hyperthyroidism

Area of Science:

• Pediatric Cardiology
• Endocrinology
• Echocardiography

Background:

• Hyperthyroidism (HT) in children can affect cardiac function.
• Previous studies suggest cardiac alterations in pediatric hyperthyroidism, but comprehensive echocardiographic evaluation is needed.

Purpose of the Study:

• To evaluate the cardiac status of hyperthyroid children using echocardiography.
• To assess the impact of hyperthyroidism on left ventricular dimensions, mass, output, and contractility.
• To investigate the reversibility of cardiac changes after treatment.

Main Methods:

• Echocardiography was performed on 18 hyperthyroid children.
• Measurements included left ventricular end-diastolic diameter (LVEDD), left ventricular end-diastolic volume (LVEDV), left ventricular mass (LV mass), left ventricular output (LVO), and peak systolic ejection rate (peak dD/dt-syst).
• Cardiac parameters were compared to predicted normal values and assessed after treatment to a euthyroid state.

Main Results:

• Mitral regurgitation (MR) was observed in 33% of black children but none of the white children.
• Increased LVEDD and LVEDV were noted in patients with MR.
• LV mass was significantly increased in hyperthyroid children compared to predicted normal values.
• Left ventricular output (LVO) was higher in hyperthyroid children due to increased heart rate.
• Enhanced left ventricular contractility was indicated by an increased peak systolic ejection rate.
• Cardiac changes showed partial reversibility after treatment to a euthyroid state.

Conclusions:

• Significant cardiac alterations, including MR and increased LV mass, occur in children with hyperthyroidism.
• Echocardiographic findings suggest enhanced left ventricular contractility in pediatric hyperthyroidism.
• These cardiac changes may be partially reversible upon achieving a euthyroid state.