Lets take a general case.
P=F/A and F=ma.
So we know pressure is directly proportional to force and force is directly proportional to acceleration. Acceleration is the first derivative of Velocity, which means the higher the rate of change of velocity the higher the acceleration. So i don't think they are inversely porportinal. Sorry, but that's what seems logical to me. I do not think they are inversely proportional. Post the whole problem here, and that might help you out.