You should make sure that every time thyroid blood work is run, FREE T4 and FREE T3 are also run. Meds decisions should never be made on the basis of TSH alone. Your FT4 before starting meds (0.40) is well below most FT4 reference ranges. I'm very surprised your TSH wasn't even higher than it was. For example, my TSH on diagnosis was 60-something, and my FT4 was 0.4. I'm also very surprised that 25 mcg, a very small dose, brought your TSH down as much as it did. Your FT3 level might explain the discrepancy between FT4 and TSH.
If you're not comfortable asking for another set of labs, this one complete with FT3 and FT4, you can order them online without a doctor's order.
Those were the only lab values that were given to me. She said the normal for the TSH was 0.4-4.0. My symptoms seem to be ok at the point but really the only symptom that I originally had was the frequent PVCs.
Please post any other thyroid labs they ran and include reference ranges. They vary lab to lab and have to come from your own lab report.
How are your other hypo symptoms doing?