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Professional basketball players are, by definition, taller and stronger and more physically active than the rest of us. Their hearts are different, too.

Now, a new analysis of cardiac tests on more than 500 active NBA players offers the first solid look at what’s normal for these abnormal individuals.

The findings, published Wednesday in JAMA Cardiology, could prove helpful to teams trying to make sense of their players’ stress echocardiograms, which the NBA began requiring in 2006.


It’s well-known that the heart changes with long-term athletic activity. It becomes bigger, heavier, and thicker. “But we don’t know where the boundaries are,” said Dr. David Engel of Columbia University Medical Center and New York-Presbyterian Hospital, who led the research team. “There’s a gray zone between the athletic changes that you [typically] see versus underlying cardiac conditions that put people at risk.” His team’s goal was to draw a sharper line in that gray zone.

Take the case of power forward Channing Frye.


At last week’s NBA trade deadline, the Cleveland Cavaliers acquired Frye from the Orlando Magic to bolster their bench and make a title run.

But Frye was diagnosed in 2012 with an enlarged heart, which forced him to miss a full regular season. Players must pass a physical before trades are finalized, and Frye’s trade to Cleveland took a couple extra days to clear because of additional testing related to his heart issue.

The new data will make it easier in the future for doctors to figure out whether an athlete’s heart size is within the realm of normal for NBA players — or if there is a real medical issue, as Frye had.

“That’s a spot-on perfect example,” said Dr. Aaron Baggish of the Massachusetts General Hospital Heart Center, who wrote a commentary to accompany the new analysis.

Without the right data set — and the right doctor, he noted — “you end up with a lot of uncertainty that can get in the way of healthy people getting on the basketball court.”

Another recent example: forward Jeff Green, who was just traded from the Memphis Grizzlies to the Los Angeles Clippers. In 2012, Green was diagnosed with an aortic aneurysm and had season-ending surgery.

Green’s aorta condition was “right on the borderline,” Baggish said, and many doctors who specialize in treating athletes “scratched their head around that case.” The new data will help in the future by laying out “the upper level of normal” for NBA players’ aortas, Baggish said.

Engel, too, singled out the aorta finding as particularly notable. Scientists already knew that the aorta, which pumps blood from the heart to the rest of the body, widens in diameter with more athletic activity. They had relied on a formula to predict how wide it should be in bigger athletes.

But Engel and his colleagues found that the widening actually plateaued at the top end of the body scale for NBA players. That means the formula might not be reliable for very tall players — and doctors should take a close look at extra-wide aortas, and not assume they’re normal just because the athlete is tall.

The new analysis could also help in diagnosing players with Marfan syndrome, a genetic disorder that affects connective tissue and is more often seen in very tall people. The blood vessels of people with Marfan can become “very stretchy,” as Engel put it, and that can be particularly dangerous if it leads to tears in the aorta.

It is a real concern: At the 2014 NBA Combine, where incoming rookie players are evaluated, Baylor University center Isaiah Austin was diagnosed with Marfan syndrome. Out of concern for his health, he did not pursue a player career in the league.

The analysis also found variation in heart muscle thickness and geometry between African-American and white players. “This is new information, because people of this size haven’t been studied,” Engel said. Most research on athletes and heart health has been based on European athletes from sports such as soccer.

The bottom line: “There’s no one type of athlete’s heart,” Baggish said. But the picture of what’s normal for the atypically athletically gifted just got a little clearer.