“The right chamber of the heart does the work of both chambers after surgery,” she said. “Essentially, it’s half a heart.” The problems bring baggage.

Surgery: A Better Half-Heart. 4 minute read. TIME. April 29, 1966 12:00 AM GMT-4.

Luka McDonald's doctors call him a miracle. Doctors said the boy born with half his heart would be lucky to live to age five. But, the now 12-year-old is thriving after receiving a heart transplant.