The nurse quickly performed CPR on the patient who had a heart attack.

CPR 是 CardioPulmonary Resuscitation 的缩写，由 cardio-（心脏的）、pulmonary（肺的）和 resuscitation（复苏）组成，字面意思是"心肺复苏"，指通过人工呼吸和胸外按压来维持心脏骤停患者的血液循环和氧气供应的急救技术。