Interested to hear how other runners cope with Paroxysmal Supra-Ventricular Tachycardia (pSVT / SVT).
Looking back at my garmin data, I've had episodes in 4 out of 78 runs over the past 8 months ... the first two episodes were last year and happened during the (only) two times I'd run shortly after taking ibuprofen. The first was prolonged (happened twice on the same run, each for many minutes) but it was during my first race and at the time I assumed the perceived exhaustion was "race-related" and that the monitor readings were some artefact. The second was a very short episode on a slow run but I recall feeling suddenly "puffed out" for a minute or so before recovering. When I saw the heart rate trace later, it made me reconsider the first occasion ... and I've never taken ibuprofen again before a run as a precaution ... and thought that was that.
However, I've had two more events, one last weekend (two episodes in the same run) and one 7 weeks earlier. Inbetween these I set a 5K and 10K PB so I'm in reasonable shape. I was convinced after the first 2009 episode that it wasn't something artefactual about my monitor but was real ... I could tell when it happening before noticing the numbers on my garmin (I feel "drained/puffed out" almost as if I've just finsihed an interval sprint). After last weekend's 13 mile run, when it happened twice, I thought I'd better find out what's going on!
I'm 42, recent 44:36 for 10K and 21:42 for 5K ... RHR is 48 bpm and maxHR is 179 bpm... my episodes/events result in a sudden shoot from, say, 140bpm or whatever I'm running at, to a riddiculous 220-230 bpm where it flucutates "normally", albeit with a new elevated baseline (i.e. they are not short-term "spikes"). As soon as the sudden collapse from this elevated plateau to the normal range returns, I feel fine.
I'm not sure what the trigger is yet ... it's not how hard I'm running as my recent races and interval sessions have been fine, as have most of my long/easy runs. I'd was pretty run down last week with a cough/cold and had consumed a box of lem-sips (maybe Morrison's own brand version)... I have spotted that non-prescription decongestants can be a trigger. I also drink too much coffee during the working day which is another potential trigger.
I realise from reading around that this is most likely pSVT and, if so, it's not a disasterous condition and is relatively common ... nevertheless, I'm obviously going to get it checked all out with my GP (and hopefully a cardiologist) but I always like to be prepared and do my research first (I'm a biologist not a clinician).