I enjoyed lifting after my Ross procedure for many years. Moderate weights, no power lifting, no single lifts. After 18 years of no issues and no leakage in either my aortic or pulmonary valve, I pressed my cardiologist on the subject, and he said lift how I wanted, and that I was doing fine.
I started power lifting, regularly training for one rep maxes and becoming stronger than I ever had been. I did this for about 5 months. One day, I messed up on a bench press and really struggled to finish the lift. I pulled a muscle in my ribs, so I stopped lifting to let it heal. I went in for my yearly checkup about 2 months after that injury. The echo revealed my aortic valve had developed moderate leakage and aneurysm and my pulonary valve was in moderate stenosis. No more lifting. The valves degraded pretty quickly after that.
I cannot say whether the lifting was the sole cause of the degradation of my valves, but I am sure that it did not help. I wish had not done the heavy lifting. Maybe I could have gotten another 5 years out of my Ross procedure. As it is, I had both my aortic and pulmonary valves replaced 3 months ago. I went with a mechanical aortic valve (On-X), and a homograft for the pulmonary valve. Hopefully that was my last operation. The On-X should last my life, and if the pulmonary needs replaced in 20 years, TAVR will handle that. But the added risks of bleeding or stroke and the complication of taking warfarin, a beta blocker, and another drug to protect my stomach lining is a hassle and limits my aspirations in life (no more extensive travel and doing volunteer work in undeveloped countries, for example). Thinking I might ought to have gone with the Inspiris Resilia if possible. Oh well, what's done is done.
TLDR: Don't lift heavy. Not worth the risk.