protodiastole

noun
pro·​to·​di·​as·​to·​le | \ ˌprōt-ō-dī-ˈas-tə-(ˌ)lē How to pronounce protodiastole (audio) \

Medical Definition of protodiastole

1 : the period just before aortic valve closure
2 : the period just after aortic valve closure