Application of Rules When No Specified Triggering Event. If the filings or actions in a case do not trigger the application of these Local.When it remains open, it is called a patent foramen ovale ("patent" means "open"). Patent ductus arteriosus (PDA) is a condition in which the ductus arteriosus does not close. The word "patent" means open. Interventional cardiologists diagnose and treat heart and blood vessel problems with minimally invasive techniques, often eliminating the need for surgery. An unclosed hole in the main body artery (aorta). A PDA stent is expected to cover the entire length of the ductus without obstruction to blood flow in the proximal descending aorta and proximal left PA. Depending on the circumstances, the preamble may or may not define a narrowing element of the claim. We are known around the world for our expertise in diagnosing and treating rare heart conditions with outcomes among the best in the world.