A double lung shot will put down an animal much quicker than a heart shot. Once the arrow passes through the lungs there is a sudden and extreme drop in blood pressure. As a result of this drop in blood pressure the brain immediately tells the heart to pump harder and faster thus pumping blood straight out the wounds instead much quicker and depriving the brain of oxygen much quicker resulting in a quicker kill. The heart just doesn't pump blood too well with a hole through it as it can't produce any pressure within itself in order to pump blood so the oxygenated blood that the brain does have stays there longer cause blood circulation stops and the blood basically drains instead of being pumped out.

That's why blood has a tendancy to spray with a double lung shot and drain with a heart shot.

If you put an arrow through both lungs the animal as 10 to 15 seconds to live, a little longer with a heart shot. How far an animal can run in that time depends on a lot of factors like terrain, weather, health of the deer, how alert the deer is etc...etc...