A follow up to the heart rate stuff

I saw my medical oncologist’s physician’s assistant yesterday—first time I’d met her. Somehow the message I’d sent through the portal and was why the MO’s office set up that appointment yesterday, didn’t make it into why I was there. Frustrating.

Anyway, I recapped things with the nurse and then the PA:

Runner for decades, three things have changed in my world in the last few months. About 10 days after starting the tamoxifen, I started having heart rate spikes while running. Tamoxifen was the only thing I could stop and maybe see if that’s what caused the issue, even knowing that it’s got a half life of four to six weeks (meaning it sticks around that long after stopping the medication). Heart rate is better but still spikes but I also still have three of the very common side effects from tamoxifen.

Both the nurse and the PA asked how high my heart rate had spiked—176, 189, those were the two I shared. The PA said ok clearly that’s off because your pulse just now was 48. YES. THAT’S EXACTLY WHY I’M CONCERNED.

You can see this
morning's spike

For now I’m still not taking the tamoxifen. She said that indeed it can take four to six weeks for the drug to leave, and I’m just now at three weeks. She strongly recommended a stress test, so I’ve pinged my primary care physician for a referral.

Neither the PA or I expect any heart issues to show up; I’ve got no family history to speak of, and I’m in really good shape. But then again, I will never say never again. I also have no family history of melanoma, or breast cancer . . . and here I am.

Yesterday’s run was great: no heart rate spikes, decent times for what was intended to be an easy run and I even did negative splits. I tried running again this morning since we have snow coming later today, which will probably mean no running tomorrow. Within 10 seconds, my heart rate was up to 160. So things are slowly getting better but not fully resolved.

Why Mississippi?

Until last weekend, I had four states left to visit to complete all 50. Now I will also say that my rules for counting a state as one I’ve visited are maybe a little on the strict side: I have to spend at least one night there, and eat a meal or two and see some sites. So changing planes wouldn’t count, nor would driving a few miles in and then turning around.

Biloxi was lovely, and of course the ocean is my happy place so that made it even better. The temps were warm but not crazy hot. We stayed at the Hard Rock, purely for the view from the room.

I was surprised by two, well three, things:

1. Biloxi has a lot of casinos. I think maybe that’s the big tourist draw. I’m not a gambler, I find gambling a colossal bore so we never even ventured on to the casino floor.
2. Smoking is apparently a lot more widespread there, maybe it’s a deep South thing, I don’t know. But all but one of our Ubers smelled strongly of smoke and pretty clearly all the drivers smoked. The Hard Rock also smelled strongly of smoke (thankfully not our room, it was truly a non-smoker room), but interestingly not the Beau Rivage (a more upscale casino/hotel next to the Hard Rock but without the amazing view).
3. The Sons of the Confederacy are alive and well. We went to an art museum (which was really cool) and then thought it would be interesting to see Beauvoir, where Jefferson Davis lived the last 10 years of his life. Only a honking big Confederate flag was flying there. In looking online at their website, there’s a whole program to “adopt a Confederate soldier” with the stated goal of buying and keeping Confederate flags flying all year round. We didn’t bother going in. 

But mostly this trip was a change to relax and check off a state. I have three more to see: North Dakota, South Dakota and Alaska. Kent needs one of the Dakotas (I forget which), Alaska, Vermont, West Virginia and New Mexico.

And I'm done

I did not expect side effects from the tamoxifen to kick in at such a low dose. But as I mentioned earlier, I've been having heart rate issues on my runs. Today's run if it can be called that was the worst so far.

I'm training for the next 10K race on November 9 and today's run should have been an easy 7 miles, keeping my pulse nice and low. Everything else felt great: lungs, legs, even the left pec was behaving. Unfortunately even before I finished one mile at a super slow pace, my heart rate spiked to 176.

I've been running with a Garmin for a couple of years, and a FitBit for three years before that so I know how my heart behaves and this? Is not it.

So I'm done with the tamoxifen. I'll take my chances on recurrence without the drug and focus on that 40% risk reduction offered by exercise and weight.

About those side effects

I’m on week four of tamoxifen (with another four years, 48 weeks in front of me if taken as planned). I’m taking just a quarter dose of what’s normally prescribed, and that’s on purpose. I haven’t had good experiences with drugs that interfere with hormones and hoped that a slow ramp up to the full 20 mg would mitigate any side effects.

Unfortunately that’s not what’s going on. This whole thing is further complicated by me starting Prolia 10 days before starting tamoxifen so teasing apart what’s causing what is a little difficult. Both drugs can cause muscle pain, joint pain and bone pain, all of which I have. But those didn’t start until about day 10 of the tamoxifen which is also when I noticed my heart rate getting too high while running (another tamoxifen side effect although apparently not very common) and also started having serious hot flashes.

I didn’t have hot flashes in menopause, I had more what I’d call warm flashes. But these are much more intense—sweat rolls down my face, I’ve soaked my clothes. They’re pretty intense.

But it’s the heart rate issue that concerns me the most because it’s affecting my runs. It’s not safe for me to run at my maximum heart rate for very long (it’s not good for anyone, not just me) and it’s been spiking that high a lot. Sunday’s “run” was mostly walking because my heart rate wouldn’t stay down.

I run because I love it, sure. But running also plays an important role in reducing my risk of this breast cancer recurring.  According to this study (summarized in this article), physical activity can reduce the risk of death from breast cancer by about 40%.

But what’s my risk?

I used this online calculator to run my results two different ways. The pathology report from my biopsy said that lymphovascular invasion was present, and the path report from my lumpectomy said it was absent.

Including the LVI, I have an 18% risk of recurrence in the next 15 years. When I reran the test using no LVI present, my risk is 11%.

Here are two more results using a different calculator, one with me taking tamoxifen and one without.

Taking tamoxifen

No tamoxifen

Let’s go with the worst-case scenario. If I have an 18% risk of death specific to breast cancer in the next 15 years, and I continue working out the way I normally do then my risk drops to 10.2%. Sure I could cut that 18% risk by 1/3 by taking tamoxifen but at this rate, I would lose the benefit from exercise.

As I told Kent, I don’t have a death wish, I have a life fully lived wish. I’ve scouted around the forums that have been so helpful to me and magnesium glycinate has helped others with the same sorts of side effects. I got some last night and started taking it. I’ll give the tamoxifen + magnesium at least a week. If things aren’t better, I’ll stop the tamoxifen and continue the magnesium by itself for a couple of weeks and then try again with the tamoxifen.