<prompt> Acute Aoic regurgitation is seen in all the following except:Marfans syndromeAcute myocardial infarctionBacterial endocarditisAnkylosing spondylitis  <response>: Answer is B Acute myocardial infarction All options other than acute myocardial infarction are known causes for acute aoic regurgitation. Aoic regurgitation may result from Two Major Mechanisms : allow regurgitation of blood back into LV. I. By causing valvular deformities. This is the most common cause 2. By deforming the aoic root. 