Post-inflammatory myocardial injury in young, physically active populations like military personnel presents significant diagnostic and prognostic challenges. Inflammation triggered by infections, systemic stress, or thoracic trauma may escape detection by standard electrocardiography (ECG) and biomarkers. When localized within the interventricular septum (IVS), it may impair both conduction and contractility, increasing the risk of adverse cardiac events.

Aim. To demonstrate the clinical heterogeneity of post-inflammatory interventricular septal injury and highlight the role of cardiac magnetic resonance (CMR) imaging in diagnosis and risk stratification.

Materials and methods. A comparative analysis of myocardial changes was conducted in two young male servicemembers who developed significant cardiac manifestations following presumed inflammatory triggers (infection and trauma). Clinical evaluation included ECG, ambulatory rhythm monitoring, serum biomarkers, and CMR.

Results. Both patients demonstrated preserved or only minimally elevated biomarkers, underscoring the limitations of laboratory screening alone. Case 1: a 40-year-old patient developed presyncope after pneumonia and blast-related trauma. Monitoring revealed high-grade atrioventricular block (Mobitz Type II). CMR identified focal intramural late gadolinium enhancement within the basal IVS, necessitating permanent pacemaker implantation. Case 2: a 39-year-old patient presented with acute dyspnea and fatigue after a viral infection