Depending on how long between the power outage and when you checked on the filters, what might have happened is the power outage stopped the filters and when the power came back on the filter motors started back up but couldn't re-prime the filter to get water flowing again. Since the water flowing through the filter cools the motor it sometimes doesn't take long for the motor to overheat and burn out.
As to filtering stopping for four hours, agree with the rest - shouldn't have a huge impact. Could always do a partial water change if you wanted extra insurance.
One thing, when you fixed the filters - are you keeping the old filter media or was it all replaced? Could have an impact on the cycling of the tank if for example you only had the two filters and replaced both of them with new ones and all new media. That could take away a good portion of your bacteria colonies. That being the case, not a bad idea to monitor your ammonia and nitrite levels for a week or so to make sure they don't spike.
