“Aortic insufficiency is a heart valve disease in which the aortic valve does not close tightly. This allows blood to flow from the aorta (the largest blood vessel) into the left ventricle (a chamber of the heart).”
The same article says that rheumatic fever was the main cause of aortic insufficiency in the past. Also that diagnosis was made by hearing a heart murmur and the patient having other symptoms.
This is a copy of Thomas Allen’s death certificate from his pension file. Before I received the file, I found his death certificate on ancestry.com. Finding his mother’s name to be “Clara Green” made me realize that he was my great grandmother Anna’s brother and that is the reason I sent for the Pension File.