From tachycardia to Bradycardia with inverted T waves

Hi there, I recently posted a question abt tachycardia and palpitations associated with inverted t waves and lightheadness on standing, it was suggested that I saw a specialist and my GP has now agreed to refer me for an assessment. I am currently taking Bisoprolol 2.5 mg which has been controlling my racing heart well for abt 2/12; however yesterday I had palpitations and minor discomfort in my chest all day and then in the evening my pulse fell to 45 bpm, I experienced extreme lightheadedness at this time and my legs felt like jelly. At what point is bradycardia dangerous? I have only taken 1.25 of my beta blocker today as I am worried it will happen again. My pulse was fine at 80 on waking this am but on experience if I don't take my medication I will become tachy again.

Many thanks for your advice

[Cleveland Clinic]

Bardycardia becomes significant when it causes true lightheadedness or syncope.  I think it needs to established what tachycardia you have and why you get bradycardic post conversion.  I think a monitor would be helpful in sorting that out.  Make sure you are seeing an electrophysiologist.