This suggests that the primary (atrial) pacemaker is not functioning, and the back-up pacemaker in the ventricles is determining the low heart rate. This is likely, but ocasionally the atria also responds in this manner. Talk to your cardiologist.
Here is an excellent web page discussing Bradycardia and possible causes.
http://cvi.med.nyu.edu/conditions-we-treat/conditions/bradycardia-bradyarrhythmia
There is a nice graphic showing the construction of the heart, the SA Node (the heart's natural pacemaker), the AV Node (discharges in reaction to the SA Node Discharge or can Discharge Spontaneously if the SA Node fails to discharge in time.
In addition they provide a list of things that can cause Bradycardia that are not related to the heart structure itself.
I spent some time looking at the T-Wave question. It can be a normal finding in several leads, I could not find the link to the site that I feel explained it best. Inverted T-Waves (more than just lead 3) are more common in some children, can be common in athletic people, and occasionally occur in some adults, me being one of them. I've had that all my life. The real significance is a sudden reversal, if it was positive on one EKG, then negative on the next, it indicates a pathological condition. (Not necessarily a heart defect, just that something needs a closer look). In addition, incorrect lead placement can cause inverted waveforms. What is your suggested follow-ups?
Yes, what did they say? Or they just send you home like this?
Actually I havent read from many people with bradycardia, but they might show up :) I was a "silent watcher" over months, too.
Great day to you all!