A series of strokes suffered by William J. Schroeder did not result from the artificial heart he received last month, one of his doctors said yesterday.

"Basically, there isn't any evidence that the heart has any . . . clots in it and we do not think there is any evidence for sure that it was the cause of the trouble," said Dr. Allan M. Lansing, the chief spokesman for the artificial-heart team at Humana Hospital-Audubon.

Lansing said the team came to the conclusion after studying the results of tests performed on Schroeder by the nuclear medicine department at Vanderbilt University Medical Center in Nashville.

But it was unknown what caused the stroke, he said

Schroeder was given a Jarvik-7 plastic and metal artificial heart on Nov. 25. On Dec. 13, he suffered three small strokes. Specialists spent the weekend studying results of tests performed to detect blood clots in the artificial heart or in the brain.

Doctors wanted to know whether the strokes were caused by clots that formed in the pump and then broke loose, moving through the bloodstream and blocking blood vessels in the brain.

Specialists at Vanderbilt conducted two radioisotope scans that provided images of the interior of Schroeder's heart.