"A lot more tests need to be done," Petron said. "Typically in that situation, someone will undergo an MRI or stress echo test to see how the heart reacts to exercise. Sometimes they start pumping normally."
Lotulelei, projected to be one of the first players taken in the 2013 NFL Draft, sat out other physical tests at the combine but is expected to participate in all tests at Utah's pro day on March 20.
Petron said most schools don't include echocardiograms in their general physical assessments because the tests are expensive. Often, other indicators signal possible problems, leading to further testing.
Lotulelei had no such indicators during his standout career at Utah. He made six All-America teams as a senior and was a first-team all-Pac-12 Conference player. The nose tackle finished with 42 tackles, including a team-high 11 tackles for loss and five sacks in 2012.
He also had four pass breakups, four fumble recoveries and three forced fumbles.
"Normally if someone has a condition like that, there will be shortness of breath, chest pains or something like that," Petron said. "Even if there is a positive in a test, it doesn't mean a pathology is there."
Edward Ganellen, a cardiologist at St. Mark's Hospital, also cautioned against jumping to conclusions, pointing out that the low output could be caused by a virus, among other things.
"A 44 percent output isn't terrible," he said. "For everyday things it wouldn't make much of a difference, but for a pro athlete it could make a big difference."
Ganellen said patients with the condition in Lotulelei's range typically are treated with medication.
According to Petron, using echocardiograms in screenings for athletes is a relatively new process, even at the pro level.
"Three years ago, this may never have been found and it might have been a nonissue," he said.