Hello! Thank you for asking on HCM! Regarding your concern, it is important to know the cardiac performance, that is left ventricular
ejection fraction (LVEF). If LVEF is abnormally lowered, than
tachycardia is considered a physiological compensatory reaction in order to maintain overall cardiac output. So, the first thing to do is to clarify this issue, thus LVEF.
From the other side, if LVEF is not severely compromised, or there isn't any severe associated valvular impairment, we have to investigate if a possible supraventricular
arrhythmia occurs in a recurrent fashion. An ambulatory 24 to 48 hours ambulatory ECG monitoring would be helpful to elucidate that issue, and to rule out any possible atrial
fibrillation presence or other arrhythmia as well.
If no current arrhytmia or abnormal LVEF is confirmed by the tests, then you have to check, any possible
thyroid dysfunction (blood thyroid hormone level), or possible anemia.
So to conclude, you need a comprehensive wouk up, comprising a careful physical exam by your doctor, cardiac ultrasound, Holter monitoring, and some blood tests.
Hope to have been helpful to you.
Greeting! Dr. Iliri