Hillsborough County Medical Examiner Vernard Adams said more tests are needed but Mays had hypertensive heart disease, and "the heart disease is perfectly consistent with sudden death."

After a difficult landing Saturday aboard a US Airways flight at Tampa International Airport, Mays joked to a TV station that he had been hit on the head but said he had a hard head. US Airways said no passengers reported serious injuries.

Alfred Bove, president of the American College of Cardiology, said the stress of the landing could have been a factor in Mays' death, but it would be difficult to prove: "Very high adrenaline levels could have caused an arrhythmia to start or released some plaque into his system."

The boisterous Mays, 50, known for hawking OxiClean and other products, was found dead Sunday by his wife. An official cause of death will be issued after toxicology and other tests are completed. He took prescription painkillers for hip pain, but there was no indication of drug abuse, Adams said. Mays was to have hip-replacement surgery Monday.

The Discovery Channel plans to dedicate Wednesday to Mays, running tributes and showing Pitchmen episodes starting at 11 a.m. ET/PT. Mays co-starred in the 12-part series with his business partner, Anthony Sullivan.

Contributing: The Associated Press