Hi Sam,

I would take a closer look at your anaesthetic technique then.

Have you observed the rat hearts for a longer period with occluded LAD- with the chest open, and seen how they then react. You are right, one would expect arrythmias to occur first- in humans at least. And just to be sure, you are not occluding the Left main?

You could also try occluding one of the other major branches of the heart (CX), and see if you see the same problem, would point to the problem being in another aspect of your procedure/anaesthesia.

Good luck

Sulman

HI Sulman, 

Thanks for the input. I use ketamine and domitor to anesthetize them (via IP injection), we avoid the use of inhalable anesthetics because of their cardioprotective properties.

No, but the ECGs readings show they appear to be fine after the ligation. Quite sure, but I don't think it's related to the ligation itself because I've done test runs where the animal is not cut open and they still die after 3 hours. There must be something wrong with either a) like you said the anaesthetic technique, b) the ventilator c) the intubater / intubation itself. 

The only thing that I can point out is with the last animal I tried (chest not opened, left on surgical table until consciousness was return) was that the rat's right leg suffered from rigor mortis. The left leg seemed fine and ECG recordings looked normal but the animal failed to re-establish spontaneous breathing.

Thanks,

Sam   

Sam,

Your description of right leg paralysis and failure to ween may suggest stroke. What FiO2 concentration are you utilizing? Are the rats from the same litter? If so perhaps a genetic issue. Good luck.

Hi Christopher, 

Interesting, I've started using carbogen (95% O2 / 5% CO2), which from what I've been told, is standard for surgery. I'm not sure, but considering that this has occurred with my last 5-7 animals perhaps it is  a genetic issue.