Drop in Heart Rate and Blood Pressure During Exercise
I wanted to tap into the collective wisdom of the board since my doctors haven't been able to diagnose the issue.
This past spring I developed an issue while exercising (speed walking - 2.8 to 3.0 mph). After going 2.3-3.0 mi, my HR will suddenly drop (less than 30s) to my resting HR (I have a Galaxy Watch, Wahoo arm band, and Polar H10 chest strap). I then become dizzy and feel fatigued; furthermore, I am unable to raise my HR more than 10-20 bpm and am just dragging along trying to get home. This happens almost all the time I go out to exercise, but is now varying in distance/time of my walk. I measured my BP with a reliable wrist cuff and my systolic falls to <110 and diastolic to 60-45.
I am 67, fairly active, and do a fair amount of hiking. I am T!D for over 54 years, with no CAD, , and have had 3 stents placed in my RCA in the previous 6 years. In December I had a Medtronic single lead Azure PM replaced with a Boston Scientific Accolade PM, again with single lead. The initial diag. was SSS, chronotropic incompetence. My lower rate is set to 60, and upper to 150 but reduced recently to 140. The cool down period is set to 8 min. Within the past month I had a stress test on a treadmill, and a nuclear medicine stress test. Both showed no problems either with the PM or vascularization of the heart. My ejection fraction is 61%. My last echo cardiogram showed no enlargements of chambers or other problems. I wore a Holter monitor in April, but it did not show any problems.
I do have high blood pressure that is hard to control. I was on 20 mg Lisinopril and 25 mg of HCTZ. However, I was having orthostatic hypotension in late afternoon an during the evening, whcih was resolved when the HCTZ was stopped. Beta blockers had a small effect on BP and caused fluid retention.
The HR drop has yet to occur when I am using my elliptical, which is indoors; but I assume that it is not as rigorous or as long as my walks. And during the cold months after PM replacement used my elliptical or went for shorter and less strenuous speed walking.
The EP doc says there is nothing wrong with the PM, and the cardiovascular doc says there is nothing wrong with my heart. Has anyone experienced such symptoms, or know what could be causing this?
Thanks for taking the time to read this post, and any ideas of what is causing this.