Fit and active 30yo white F with no significant medical history, normal BMI (5'9" 68kg), taking contraceptive pill. Had palpitations about 10 years ago (ECG at the time was fine and they resolved with time). Family history of SCD (maternal grandfather and his brother died in their early 50s; maternal uncle had acute onset illness that resulted in mitral valve replacement; maternal cousin has heart murmur).
Symptoms include shortness of breath on exertion and chest pain, plus transient desaturation that lasts anywhere from 15 seconds to a couple of minutes (per pulse oximeter). Resolves with rest. Very occasional palpitations have resumed. In the most extreme episodes I have struggled for breath, nearly fainted (but remained conscious), broke out into a sweat, had to lie down (in the street…) and desaturated to 75%. Symptoms emerged about 6 weeks ago after a week or two of decreased performance (getting out of breath during runs).
Blood work: “Pristine” according to my GP, with the exception of low Alkaline Phosphatase (39 u/L) and lowish B12 (191 pmol/L – I think unlikely to be diet related as my diet is good, non-vegetarian and I eat a lot!)
Resting ECG: Initially detected left ventricular hypertrophy; subsequent echo revealed this to be a false positive.
Echo: Don’t have results to hand, but apparently they looked good and disproved LVH.
Pulmonary function testing: Looked good (apparently I have big lungs!)
6 minute walk (brisk-ish): No desaturation (using oximeter strapped to my forehead), but my heart rate spiked to 216 BPM.
X-Ray: Looked good.
Chest CT scan: Looked good (no blood clots).
Stress echo: Reached 85% heart rate capacity whilst walking and took a while to recover my breath. Echo looked good, minor ST changes of 1-2mm of horizontal/down-sloping diffuse ST depression. Normal BP response.
Bubble test: No sign of hole in heart, although with Valsalva there were late bubbles seen in LV. Doctors initially put this down to my body working very efficiently (because I am a runner) or a small PFO, but are now wondering about fast transit through lungs and anomalous pulmonary drainage.
Holter monitor: 2 ventricular ectopics and 2 supraventricular ecoptics (all during a period when I was walking briskly). Isolated beats only (no couplets). Multiple episodes of ST depression in channels 1, 2 and 3 of -4mm to -5.6mm, all occurring during the same period I was walking briskly. All episodes corresponded to times I was experiencing symptoms. Conclusion no arrhythmia, but heart is under stress.
My doctors are great and are working super hard on this “unusual case”. However, life as I know it seems to be on pause and I am at a loss. I would be very grateful for your thoughts.