What types of cardiac conduction abnormalities would lead you to avoid using tricyclic antidepressants?  

QT and QTc—I always check for these in new patients. Prior to prescribing, and especially in cardiac and elderly patients, use caution. Also, there may be other drugs on board that alter heart rate and pose a threat to rhythm. Some patients who have been stable on tricyclics for a long time...

Agree that AFib itself is not a contraindication, but rather QT prolongation. The challenge is that as cycle lengths vary, so do QT intervals. Definitely a question of growing importance that merits future outcome studies. 

I wouldn’t say it is a definite contraindication. But, I would want to be sure it is a longstanding patient and they are seeing a cardiologist regularly. Then, if the QTc were within reason, I would consider it; but it wouldn’t be high on my list of options. ...

Abnormally prolonged QTC.

Most of the TCA are prescribed by primary doctors for chronic pain. May consider discussing about the use of Cymbalta as the first option under the most recent guidelines for the treatment of chronic pain.

I have had a few patients on tricyclics over the decades, get lost to follow-up, so I would choose not to use the tricyclics anymore.