The statement, cited by US media, said the exact cause of the senator's death will be determined after all necessary examinations are completed

Graham's death sparks questions on cardiac arrest that is caused by an electrical malfunction in the heart that disrupts its pumping action. The heart then stops beating.

Sen. Lindsey Graham died at 71 of an aortic dissection due to arteriosclerotic cardiovascular disease. An ER doctor explains why it kills so fast and the warning signs.