Billy Mays, who elevated the art of the television sales spiel to a fevered pitch, apparently died of a heart attack, Florida authorities said this morning.

Preliminary autopsy results show that Mays suffered from hypertensive heart disease, Hillsborough County Medical Examiner Vernard Adams said during a televised news conference this morning. Toxicology and tissue tests will take several weeks before a final cause of death is issued, he said.

Mays, 50, was found dead in his Tampa home on Sunday after returning to Florida on a commercial flight that sustained a rough landing on Saturday. Mays had said that he had bumped his head during the touchdown.

But Adams said the autopsy showed no evidence of trauma to the head, either external or internal.

The autopsy showed that Mays' heart was heavier than normal because the left ventricle had enlarged, a symptom of heart disease, Adams said.

Adams said authorities had ruled out prescription drug abuse. Mays was taking prescription painkillers Tramadol and hydrocodone for hip pain, but the pill counts showed that Mays had taken the correct amount, according to the medical examiner.

michael.muskal@latimes.com