Tramadol is not related to propranolol in any way. It is a coincidence that it has the --ol ending in its name.

The nausea from tramadol is from the mu receptor overload and is similar to the nausea from opiates therefore.

80mg extended release is the second lowest dose of extended out there. 60mg is the lowest. Propranolol also comes in immediate release starting at 10mg.

This would have blocked your palpitations completely I suspect.
Propranolol is one of the main drugs used to treat the signs of hyperthyroidism... It does not TREAT or change the cause, but will keep the heart from going crazy that many Graves' patients complain about. It is often used as a symptomatic aid for those patients to be more comfortable, and lessen the stress on the heart.

Headache is not a common side effect of this drug.
Here is a more comprehensive listing:
http://www.drugcite.com/?q=propranolol

Propranolol is a very old drug... It was just FDA approved in the early 70's after success in the UK. It is not first line anymore for blood pressure control (like I had) because the newer betablockers were developed to have fewer side effects. But it is still used for the indications I listed above. It is very effective for hyperthyroidism patients.