Heart attacks are frightening by themselves, but they're made worse by the potential for lasting damage. Even a brief interruption to blood flow could permanently destroy vital tissue that keeps your heart beating as usual. However, there might be a way to mitigate or even prevent that damage. Scientists have discovered that a light-sensitive bacteria, synechococcus elongatus, can keep oxygen coming in the midst of a heart attack. Much like a plant, the bacteria both draws on photosynthesis for energy and turns both CO2 and water into oxygen. If you expose it to light soon after the attack, you can maintain oxygen levels and increase the heart's blood-pumping ability after the attack is over.
In lab rats, the results were dramatic. Oxygen levels were 25 times higher 10 minutes after the attack, and the hearts pumped 60 percent more blood 45 minutes after the attack. If you could use this as an emergency treatment in humans, it could mean the difference between outright heart failure and a reasonably healthy patient.
The emphasis is on "if," however. It's easy to shine light into the small body of a rat; it's tougher to do that with humans, who have thicker heart muscles (and are much larger, of course). There's also the question of whether or not the bacteria are completely safe. Don't count on this solution reaching hospitals soon, if at all. Nonetheless, the discovery is promising: it suggests that there's a way to protect your heart against long-term harm even as doctors race to save you from the immediate threat.