[ArchD]

Using a time unit not related to the metric second would be a step back. If you use a new unit equal to half a metric second, that's too fast for normal human heart rate.

[npsimons]

Not to mention it's highly variable; I've easily gotten my heart rate up to 192 BPM; when I was in better condition, my resting was mid-forties.

[diminish]

yes, not half but a bit slower. i read this from a book long time ago, but don't remember where. the guy was saying that the 'second' was a bit slower than the average heart beat rate and that made people generally unhappier because it is reflected in many things during a day.