The nurse is assessing a p atient' sarterial w ave form and not es a not chon the descending portion of thew ave form. The nur se associa tes thisnot ch with which phy siologicalevents?cl osur e of the aortic val veWhich of the fol lo wing waspr escribed to decr ease cardiacpreload and aft erl oad and toincr ease the bl ood flo w t o themy ocar dium?Mr. Ethan Gruppman , a 55-y ear-oldbusinessman on a business trip , hasbeen br ought t o the ED by acol lea gue with SOB and ches t p ain.One hour a go , Mr . Gruppman beganto e xperience "indiges tion," whichwas unr elieved by ant acid, aft er ahea vy meal. Mr . Gruppman is 5 '6 " tal land weighs 17 5 pounds. He has ahis tor y o f hypert ension and highcholester ol f or which he tak escapt opril 50 mg twice a da y andsim vas ta tin 20 mg once daily. Hisfa ther , 7 4, has had two MIs; hismother recentl y died of a CV A a t a ge7 2. Mr . Gruppman tak es fr equentbusiness trips, ea ts