Hello, I Want To Understand What Damage The Described Event

Hello,

I want to understand what damage the described event did to my heart.

Last winter, while on a ski trip to high altitude (9000 ft), I experienced a severe drug-induced tachycardia episode. I had been skiing six days, so my heart was fatigued. On the last night, I consumed edible cannabis candies, totaling 20 mg THC (this is a very high dose).

An hour later, severe tachycardia started, and lasted 1-2 hours (at least). My heart was beating so fast it could barely keep up with itself. The rate had to be over 200 bpm. An hour into this I took 2 grams Xanax to reduce anxiety, which helped me get to sleep.

Since that event, I have been experiencing more arrhythmias/palpitations (PVCs, PACs, extrasystoles, fluttering, etc). I did have them before that episode, but had them much more frequently after. I also had a new sensation in weeks after the event: the sensation of long pauses in heart rhythm, or at least very slow/weak heartbeat.

I since had two 12-lead EKGs. One showed slightly long QT interval. Otherwise they were normal. I've had two holter/event monitors and those were "normal."

With this information, can you tell me if it is likely the tachydardia of 1-2 hours, in hypoxic state, and on fatigued heart caused any damage to the heart muscle or electrical circuitry of the heart?