I am not aware of a disease that would connect the two symptoms. The most likely cause of the chest pain
would be a musculoskeletal strain exacerbated by the sneezing
. If the echocardiogram was normal, you can consider a stress test for further cardiac evaluation if there is still concern about the heart. If these tests are negative, I would consider physical therapy to evaluate the chest pain.
I agree with the ultrasound to evaluate the abdominal "pulsing".