Sudden muscle failure, what are the possible causes

I lift weights 5 days per week. Today I was at the end of a chest workout and was doing dumbbell bench (flat bench) with 95lb dumbbells so heavy but not a PR. I was feeling good and it was moving smoothly. A few reps in, suddenly my right failed. By failed, I don't mean the regular stalls out and you can't make the rep. I mean was going smoothly up and dropped like the muscle just quit working. The failure happened in a split second. I exited safely and dumped the weights.

There was no pain and no feeling of strain. Just a sudden complete failure. No pain or injury afterwards either. I have never experience anything like this before. And it is not a tear, I have done that before and tears hurt.

The question: Have any of you experienced this or know what might have caused it?

 

Thanks guys. My GP specializes in sports medicine so I will ping him; it is not why I picked him but that is where he settled.

That shoulder has always been weaker than the other. Or at least since I tore it up about 25 years ago lifting. It hits a point and it feels like it looses power but usually it just hits a point where I just can't push harder/hard enough, then I stall and my spotter jumps in to help. Pretty typical. Last night was sudden failure so it really felt different.

This morning chest and shoulders are soar, and that side somewhat more than the other, but nothing out of the ordinary for a heavy lift day. So from the good news side it clearly isn't injured.

 

Thank you all for the feedback. We didn't find anything abnormal. Many years ago I tore up that shoulder lifting. Even today it is not as strong as the other one and it reaches failure first. Since the first post I have gone to failure a few times (drop sets etc.). I have noticed that when I am drop setting failure generally comes a little more gradually but at heavy weights it is a bit more sudden. So at this point I am going to chalk it up to fatigue/failure.

 

Didn't find anything and all is going well since. Probably fatigue and at that weight it just failed. Getting stronger still and it is about time to add some volume to the mix again.