0
This seems pretty strange to me. Billions of people have died and are alive today and we've only just now figured this out. Is that really true? My uncle had a heart attack and he's 85 and his heart rebuilt itself. That's what the doctor said so I'm confused by this. Is this really new?
Yes, this is genuinely new—Australian researchers just published the first direct evidence that human heart muscle cells divide after a heart attack—but the regrowth is small, and "your heart rebuilt itself" goes beyond what the evidence shows.
Why it matters: It overturns a long-standing medical teaching that cardiac damage is permanent, and opens the way toward treatments that amplify the heart's own repair.
- The study, published in Circulation Research, found about 11% of heart muscle cells near the attack site showed signs of mitosis; biopsies taken 7–10 days after an attack showed 7–8%.
- That is real but far from enough: senior author Sean Lal says rebuilding a damaged heart would require 25–50% of cells to divide.
- Rodent studies showed this for 25 years, but no one had proven it in living human hearts until this team used tissue collected during bypass surgery.
- The team's new pre-mortem biopsy method lets researchers collect living tissue from the damaged heart's border zone, giving them a lab model for testing regenerative therapies.
Room for disagreement
- Coverage splits on how to frame the finding: the University of Sydney calls it heart muscle "regrowth," but the researchers themselves stress the natural increase in cell division is too low to replace lost tissue—so a doctor telling a patient the heart "rebuilt itself" likely means something more modest, like recovery of function, not new muscle at a regenerative scale.
AI-generated with web search — may be wrong. Check the linked sources.
