Welcome to Health Care Magic
It is probably reduced blood supply to brain from the fast heart rate
Sweaty palms again may be from this / or reactive anxiety
from the situation
probably may account for these features...get it investigated...beats need to be DOCUMENTED by ElectroCardioGram (EKG). Standard ECG records the electrical activity of the heart, for a few seconds. It can detect the arrhythmia occurring during that time only. If the episode occurs randomly or precipitated by a specific activity like exercise, one needs Holter or event monitor.
Condition like Pheochromocytoma
can cause episodic fast rate, high pressure, sweaty palms. There are blood tests to estimate the adrenal hormones or their metabolites...
Wishing speedy recovery