Could propranolol cause tachycardia? purpose to treat a tremor & less than a week after, my hr constantly spiked. no longer taking. ongoing for a year

No: If anything, heart rate would be slowed by propranolol. Even if this were a rebound phenomenon from a drop in blood pressure, once the drug effects cleared, normalcy would return, look for another cause such as caffeine, stress, decongestants, low blood pressure, and such. Make an appointment for a full,check up to diagnose this, then treatment can help resolve this problem.