23M — Unexplained exertional tachycardia, chest pain, flushing/palpitations
23M with a history of SVT. Over the last ~6 weeks I’ve had a major change from baseline. Minor activity like showering, stairs, walking or working causes tachycardia, chest pain/tightness, SOB and pounding/palpitations, and my HR can stay elevated for hours afterward despite resting.
At complete rest, my HR can be normal or even in the 50s–60s.
I also get episodes of significant flushing/feeling hot, sweating, head/neck pressure, nausea and occasional lightheadedness when struggling with this chest pain/palpitations.
Workup so far: CAD-RADS 0 coronary CTA, echo showing mild LVH, 13.4-MET treadmill without ischemia/significant arrhythmia, and negative ER cardiac workup. The tachycardia captured so far appears to be sinus. Awaiting holter results.
Higher-dose metoprolol lowered my resting HR into the 40s–50s and BP into the 90s/50s without resolving the exertional symptoms, so I was switched to low-dose nebivolol.
I recently saw a new cardiologist for another opinion. An S4 was heard on exam, and based on the overall presentation, the doctor also raised concern about ruling out a catecholamine-secreting tumor such as pheochromocytoma/paraganglioma. I also have a longstanding small lateral neck lump that may be completely unrelated but is now being considered as part of the workup.
I’m not looking for a Reddit diagnosis—I’m curious whether anyone has experienced a similar situation where the cardiac workup was largely reassuring but the symptoms persisted and something systemic/endocrine ultimately explained it.
What did it end up being, and what testing finally gave you an answer?