TNNI3 and pericardial effusion: Ancillary test results were as follows: hs‐cTnI: 0.054 ng/mL (0–0.016); NTproBNP: 1594.0 pg/mL (<150); A contrast‐enhanced CMR revealed the diffuse thickening of the left ventricular wall with multiple abnormal enhancements, reduced left ventricular systolic and diastolic function, and moderate amount of pericardial effusion.