I would suggest an implantable loop recorder, which can stay in for 18 months and record any such events. Your cardiologist wants to know where it is coming from because the risks are different depending on location, and it may not be possible to approach some of these at most centers. Are you on a beta blockers and or antiarrhythmics? These are very useful for most patients to decrease or even eliminate these symptoms.
Generally speaking, unless sustained for hours, these are not life threatening problems, and can be worked up as an outpatient.