Help Matthew with medical expenses

My son Matthew is a 32 yrs old truck driver who got a virus in March 2021. This virus attacked his heart and in Nov was admitted to Mayo hospital. There he was diagnosed with dialated cardiac myopathy and they found a blood clot in his heart. While doing tests they also discovered a hole in the heart called atrial septic defect. He is now in catastrophic heart failure (heart is functioning at 16 percent)