congenital heart disease

Congenital heart disease means the heart did not finish building itself correctly before birth. Think of a house whose plumbing was laid out slightly wrong while it was being constructed: a wall left with a hole, a pipe connected to the wrong tank, or a doorway that should have closed but stayed open. Because the error is baked into the original blueprint, it is present from the very first heartbeat rather than developing later in life.

These defects arise during the first weeks of pregnancy, when the heart folds from a simple tube into four chambers with valves and great vessels. Some are tiny holes that close on their own; others scramble the connections so severely that survival depends on surgery in the first days of life. Defects are often grouped by whether they let too much blood flood the lungs, too little reach the lungs, or allow blue (oxygen-poor) blood into the body's circulation.

Many causes overlap genetic conditions, certain infections or exposures during pregnancy, and chance, and in most individual cases no single cause is ever identified. Thanks to modern surgery and catheter-based repair, most children born with these defects now reach adulthood, creating a growing population of adults with congenital heart disease who need lifelong specialist follow-up.