APCU25CR8 When strength masks vulnerability: athlete’s heart in active soldiers – a case series

Introduction In the military, endurance and strength symbolize peak readiness. Yet, behind this resilience, athlete’s heart can blur the line between normal adaptation and true disease. The challenge is knowing when to reassure and when to act.Case Presentation Case 1: The Triathlete’s Dilemma A 38-year-old serviceman presented with reduced stamina and exertional breathlessness two weeks after completing a triathlon. ECG showed sinus rhythm at 60 bpm. Echocardiography suggested mildly reduced ejection fraction (46%) with global wall motion abnormality. It is also exhibiting features consistent for athlete’s heart with supranormal lusitropic function, i.e E/A ratio >2 and a supranormal both e’ driven by a very pronounced early diastolic suction effect from the left ventricle. NT-pro-BNP level and coronary angiography result were normal. Cardiac MRI confirmed normal LV size with mild systolic reduction; these findings are consistent with physiological remodelling rather than cardiomyopathy. Case 2: The Instructor with Presyncope A 39-year-old military fitness instructor had episodes of presyncope after a half marathon. Initial evaluation was normal, but Holter monitoring revealed nocturnal slow atrial fibrillation (AF) with average HR below 50bpm. The AF burden is 7,4% with maximum HR of 80bpm. Echocardiography and Exercise Stress Test (EST) were normal, and he remained asymptomatic afterwards. Case 3: The Young Soldier with AIVR A 24-year-old soldier reported experiencing frequent pre-exercise dizziness in the mornings. An ECG upon arrival showed an idioventricular rhythm (IVR) with a heart rate of 48 bpm, which resolved after bedside exercise. Holter monitoring documented few episodes of nocturnal IVR. Echocardiography features are consistent with athlete’s heart. He demonstrated excellent chronotropic competence on treadmill testing (stage 5 of the Bruce protocol).Discussion These soldiers illustrate the paradox of athlete’s heart: endurance training can mimic cardiomyopathy, and arrhythmias may occur even in highly fit individuals. Multimodality evaluations, including NT-proBNP levels, EST, Holter monitoring, echocardiography, and cardiac MRI, are crucial for differentiating the normal cardiac adaptation to exercise from pathological heart disease.Conclusion Athlete’s heart can mask underlying pathology in otherwise strong soldiers. Recognizing the potential overlap with true pathology is crucial to avoid unnecessary medical restrictions while simultaneously ensuring both their safety and continued military service.