Can congenital heart defect heal itself within three to four years?

Sometimes: If you have a defect that requires surgery as an infant, waiting for it to heal itself is not an option. Some defects such as a small vsd, asd, or PDA may close over time. With small defects you can sometimes take a "wait and see" approach.

Yes: Some cardiac defects may close by themselves. Also mild narrowing of valves like the pulmonary valve can sometimes resolve with age.

Some do some don't: A small VSD (hole between lower chambers) is a common defect that often closes spontaneously in the first year. A big one can lead to heart failure if neglected. Each defect must be monitored closely and treated based on need.