SICK chihuahua

Our 13 yr old femal chihuahua has "spells" about every 2-3 nites. During her sleep, she yelps out usually wakes us up and then is very ...I guess the description would be incoherant? I don't think it is seizures, because she is not still and no foaming. We think she might have congestive heart failure, but no, not taken in to a vet yet. Do you think these spells could be heart attacks?
   
She also has an extremely fast heart beat during and after the attacks and last nite, first time, her mouth was open some and drewling. On occation, it almost seemed as her heart had stopped for a few seconds? Would appreciate any advice you can give until we can get her into the local vet.
   
Thanks

Some dogs having seizures will paddle their legs, some will drool, some will cry and whine, some will lose control of their bladder and bowels, some will experience all of the above and most will act incoherent after the episode is over. If she is having seizures it could be from a liver problem, which is frequently the case in older dogs.
   
The best case scenario is she is having vivid dreams and that would certainly raise her heart rate, but so can seizures.
   
She really needs to be evaluated by a vet who will do blood work and other tests.
   
Be aware that sometimes dogs have seizures and yet all the tests appear normal, so it is sometimes beneficial if you can take her to a vet right after she has one of her episodes so they can evaluate her then.
   

trie playong the hole day then he will be tired at night and go to sleep