Aortic Regurgitation In AR the problem is in closing aortic valve,which closes in diastole.The blood leaks back into left ventricle.This increases left ventricular end diastolic volume,which results in increased stroke volume [increased systolic pressure].Blood draining back into left ventricle produces a drop in diastolic pressure.This wide pulse pressure is manifested by a hyper dynamic circulation. __________________ this can be explained in a very simple manner, systolic pressure is actually left ventricular pressure, and diastolic pressure is stretch on aortic wall, now if there is aortic insufficency, blood will go back into left ventricle, increasing its pressure i.e systolic pressure, and there will be no blood in aorta, decreasing the stretch ie diastolic pressure, this will increase pulse pressure. Source