Talent agent Mark Swain Upchurch died of a heart attack in New York City on April 26. He was 47.Upchurch began his career in New York City as a talent agent in the children’s department of J. Michael Bloom Agency. In 1996, he segued to the Henderson-Hogan Agency. In the following years he was also an agent at Peter Strain & Associates and Leading Artists. A native of Durham, N.C., Upchurch is survived by his domestic partner, Darley Junqueira; his mother; and two brothers. A funeral service will be held Wednesday at 6 p.m. at St. Bartholomew’s Church in Gotham.