Sepsis induced myocardial dysfunction (SIMD) increases mortality risk to 70-90% compared to sepsis without cardiovascular system dysfunction. Troponin is a specific and sensitive marker for myocardial injuries, where high troponin levels are frequently reported in critically ill adult patients. However, very few studies are available on systolic and diastolic heart functions in child patients with sepsis in relation to troponin levels. This was a prospective cohort research to assess the troponin levels and the relationship with systolic and diastolic dysfunction at 24 and 72 hours of pediatric sepsis at the PICU in Haji Adam Malik and Universitas Sumatera Utara hospitals Medan, Indonesia. The relationship between the mentioned variables was assessed using paired t-test for normal distribution or Mann-Whitney test for non-normal distribution data. Research subjects were children aged between 1 month to 18 years old that fulfilled sepsis criteria according to PELOD-2 scoring system. Patients with congenital heart diseases and myocarditis, as well as post-heart surgery patients were not included in the study. The frequency distribution of systolic and diastolic function showed no systolic dysfunction in patients. However, diastolic function assessment showed 8 patients (26.7%) with diastolic dysfunction on the first day of sepsis diagnosis, and the number increased to 11 patients (36.7%) on the third day of sepsis diagnosis. Troponin I and T showed a significant relationship with diastolic dysfunction (p<0.05). Troponin T and troponin I values measured on the first 24 and 72 hours of sepsis diagnosis or PICU treatment can indicate diastolic dysfunction.