Kounis syndrome is an allergic acute coronary syndrome. It occurs on healthy or pathological arteries. Its complications, although often benign, can lead to cardiac arrest and death. Its triggering factors are multiple and include contrast products used in diagnostic imaging. We report the case of an 81 years old patient affected by hepatocellular carcinoma, who presented a type 2 Kounis syndrome with inferior myocardial infarction, complicated by cardiac arrest related to complete heart block following a gadoteric acid injection.