Eisenhower initially planned on serving only one term, but he remained flexible in the case leading Republicans wanted him to run again. He was recovering from a heart attack late in September 1955 when he met with his closest advisors to evaluate the GOP's potential candidates; the group concluded that a second term was well advised, and he announced that he would run again in February 1956.
On September 24, 1955, President Eisenhower suffered a heart attack; his condition was initially believed to be life-threatening. Eisenhower was unable to perform his duties for six weeks. The 25th Amendment to the United States Constitution had not yet been proposed, and the Vice President had no formal power to act. Nonetheless, Nixon acted in Eisenhower's stead during this period, presiding over Cabinet meetings and ensuring that aides and Cabinet officers did not seek power.
Eisenhower was the first president to release information about his health and medical records while in office, but people around him deliberately misled the public about his health. On September 24, 1955, while vacationing in Colorado, he had a serious heart attack. Dr. Howard Snyder, his personal physician, misdiagnosed the symptoms like indigestion and failed to call in the help that was urgently needed. Snyder later falsified his own records to cover his blunder and to protect Eisenhower's need to portray he was healthy enough to do his job.