I've had almost every kind there is... hard thumps, soft flutters, flip-flops, machine-gun thumps, squirmies, stumbles (where it feels like your heart can't catch a normal rhythm), fast runs, you name it. The first bad run of palps I had, my doctor put me on beta blockers too... he seemed to think they kicked in when my heart was beating fast, but it turned out the opposite was true, my heart was beating fast when I got palps, due to the stress they caused.
If yours have gotten worse since going on beta blockers, you might want to tell your doctor that... while they definitely slow your heart down, they can sometimes aggravate palps in some people. Medication often doesn't always affect everyone the same way. With your doctor's help you can try around until you find what works best for you.
(edited due to communications failure... sorry, I never really developed a good sense of sequential thought!

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