Transient sensations of impending loss of consciousness: the "blip" syndrome.
jnnp.bmj.com
Momentary sensations of impending loss of consciousness may occur, particularly when a person is relaxed, without any obvious cardiac, cerebral vascular, or epileptic basis. These episodes may be a quasiepileptic phenomenon such as déjà vu and night starts and seem to have a benign prognosis.

I have experienced these ‘blips’ in the past and was deeply troubled by them, as I thought that they could indicate something serious going on.

While I don’t suggest anyone to disregard any symptom that they consider to be potentially serious (read as: consult your doctor if you suspect something could be wrong), I have noticed throughout my life many different types of ‘glitches’ such as this one that turn out to be benign and common.

To me, learning about these effects is a form of applied psychology in the sense that understanding that these feelings are normal and usually benign can help prevent health anxiety.