10+ Year Member
Sep 19, 2007
Resident [Any Field]
I was looking into the causes of inspiratory splitting of S2 and I came across this paper:

It seems to suggest that there is an actual increase in the duration of electromechanical systole when preload goes up. So does this mean there is some sort of mechanoelectric feedback going on where increased sarcomere stretch leads to a longer action potential?
I understand that the Frank Starling mechanism says preload can cause a harder contraction, but I thought that the total contraction time didn't change.