The Suns said Frye has developed a dilated cardiomyopathy, a condition discovered during an echocardiogram by team cardiologist Dr. Tim Byrne.
Dilated cardiomyopathy is a disease of the heart muscle, primarily affecting the left ventricle, which becomes enlarged and can't pump blood to the body with as much force as a healthy heart, according to mayoclinic.com.
Frye signed with Phoenix, his hometown team, in 2009 and has averaged 11.5 points and 5.9 rebounds in three seasons. He averaged 10.5 points and 5.9 rebounds last season.
Frye has also played with Portland and New York during a seven-year NBA career.