Sustained couplets during exercise

[Heckno]

I spend about 30 min/day on a stationary bike at the gym.  As my body responds to the exercise workload, pulse goes up along with breathing rate.  I check my pulse on my wrist and observe the couplet pattern: 1 strong beat followed soon by a much weaker second beat.  Spacing between strong beats is 3-to-4 times the spacing between the strong and weak beats. I have seen other discussions attributing this to PVCs and think it may be relevant.  I find this still curious in that the couplet pattern persists throughout most of my workout, about 30 minutes; but  it eventually seems to adjust to a very regular single-beat pattern toward the end of the session or if I continue much longer than 30 min.  For numbers, If I count all of the beats, my pulse runs 90-100 bpm, about what it should be for 13 mph cycling. The monitor on the bike at the gym does not detect the weak beat, so it is always off by 2.  Also, although I am in this funky rhythm, I feel no weakness nor fatigue.  All this has been going on for the many months since I first noticed it.
Anybody have a comment? Thanks, Rick

[is_something_wrong]

I don't think I know what a PVC feels like, as far as I know I don't have them (a 24 hour Holter in 2009 and a stress test at the same time revealed only PACs, and my 48 hour Holter last year did the same, the doctor said "no wide complex ectopy". The sensation of my PACs can vary greatly, depending on the timing of the beat. An early PAC causes a nasty sensation as it fires before the ventricles are done with the previous heartbeat, so atrial blood backfires.

Some of my PACs also fail to reset the sinus node, so they fall between two normal beats. It feels like three rapid beats in a row. It's still just a single PAC.

[tom_h]

Yes, PAC's.  They don't hit as hard as PVC's.  I've had this happen on occasion if I'm really fatigued, or if I haven't gotten enough sleep for a few days in a row and try to push it a little to hard.  It's sort of like a loping, or galloping beat.  I've come to realize that its my old body telling me to BACK OFF!

[is_something_wrong]

This is not a couplet. A couplet is two consecutive "weak beats". As you are able to feel the extra beats, it could be that you have PACs rather than PVCs. Still, they are single ectopics.

Maybe you should ask your doctor for a stress test just to be sure that your heart is OK? It probably is, but every 3-4 beats sounds like a lot