Sen. Bernie Sanders (I., Vt.) on Sunday waved away concerns about his unfulfilled promise to disclose his medical records before the first votes were cast this election cycle.

NBC's Meet the Press anchor Chuck Todd pushed the presidential candidate on his promise last September to release his full records. Sanders at the time said he would release full medical documentation before the first votes were cast—a deadline that, with Iowa's Democratic caucus last Monday, has now passed.

Sanders demurred, claiming that "we have released as much documentation I think as any other candidate."

"But no other candidate has had a heart attack," Todd told Sanders.

"You can start releasing medical records and it never ends," Sanders said. "We have released the substantive part of all of our medical records. We have cardiologists who have [confirmed] I am in good health. I am in good health."

Thus far Sanders has only released letters from his physicians, not full records. That choice has attracted criticism from a number of corners, including the Washington Post editorial board, which criticized Sanders earlier this month for not making good on his promise of a full disclosure.

"Mr. Sanders, like everyone running for president and currently serving as president, should be totally forthcoming about his health. The inadequacy of doctor letters in lieu of records was underscored in 2016 by the ludicrous letter from then-candidate Donald Trump's gastroenterologist," the board wrote. "So far, Sen. Elizabeth Warren (D-Mass.), 70, has provided the most information, releasing a letter from her physician and five pages of supporting medical data. Former vice president Joe Biden, 77, released a three-page letter from his physician outlining his current condition and medical history."

The 78-year-old Sanders suffered a heart attack last October. He repeatedly promised to disclose his medical records before and after the incident took place.

"The people do have a right to know about the health of a senator, somebody who's running for president of the United States, full disclosure," Sanders told CNN’s chief medical correspondent Dr. Sanjay Gupta, following the incident. "And, we will make at the appropriate time, all of our medical records public for you or anybody else who wants to see them."