Aortic insufficiency (AI), also known as aortic regurgitation (AR), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle.
Definition of echidna. : a spiny-coated toothless burrowing nocturnal monotreme mammal (Tachyglossus aculeatus) of Australia, Tasmania, and New Guinea that has a long extensible tongue and long heavy claws and that feeds chiefly on ants; also : a related mammal (Zaglossus bruijni) of New Guinea having a longer snout and shorter spines.
Hedera helix (common ivy, English ivy, European ivy, or just ivy) is a species of flowering plant in the family Araliaceae, native to most of Europe and western Asia.edera helix is an evergreen climbing plant, growing to 20â30 m (66â98 ft) high where suitable surfaces (trees, cliffs, walls) are available, and also growing as groundcover where no vertical surfaces occur.