A 66-year-old man was admitted to the emergency room because of 3-hour-long acute chest pain with dyspnea and nausea while fishing on a high-altitude (2400 m) lake in the very early morning. The patient was transferred by helicopter. Persistent chest pain without pathological clinical findings (Spo2, 99%; shock index, 0.9; axillary temperature, 36.7°C) was present. Medical history revealed no previous cardiovascular events and no further cardiovascular risk factors except smoking (40 packs a year). ECG demonstrated ST-segment elevation (Figure 1A). ST-segment–elevation acute coronary syndrome was initially suspected. Immediate selective coronary angiography demonstrated neither stenosis nor dissections. Ventriculography showed extensive left ventricular (LV) apical and midventricular akinesia with hyperkinesia in the basal segments and a moderate reduction in the estimated LV ejection fraction (Figure 1B and Movie I in the online-only Data Supplement). These large LV wall motion abnormalities were inconsistent with slightly elevated cardiac enzymes (troponin I, 0.48 μg/L [normal, <0.09 μg/L]; creatine kinase-MB, 18.7 UI/L [normal, <24 UI/L]). Clinical presentation and the absence of elevation of inflammation markers elevation and pathological viral tests and bacterial cultures made it possible to reasonably exclude acute myocarditis. ECG repolarization alteration (Figure 1C) and LV wall motion abnormalities recovered spontaneously and fully in 4 days (Figure 1D and Movie II in the online-only Data Supplement). Therefore, the diagnosis of apical-ballooning takotsubo cardiomyopathy (TTC) was made.