here u go
three kinds of cardiac holes — Patent Foramen Ovales (PFOs), Ventricular Septal Defects (VSDs) and Fenestrated Fontans (FFs). PFOs are holes in the heart needed before birth to transfer oxygenated blood from the umbilical cord to the unborn child; if a PFO remains open after birth, it creates a pathway for blood clots. VSDs are abnormal openings between the heart’s chambers that can lead to heart failure. An FF defect results from the Fontan procedure which corrects congenital cardiac defects in people born with three chambered hearts but creates a fenestration, or window-like hole, that eventually must be closed.