I was diagnosed with pots after frequent syncope w/ sinus tachycardia. but recently, i've had recurring svt and non-sustained vt. can pots cause this?

Not a cause, but a: syndrome: a collection of signs & symptoms of unknown or multiple different causes. POTS = an acronym for Postural Orthostatic Tachycardia Syndrome. See: http://www.dysautonomiainternational.org/page.php?ID=30 & look up: https://www.google.com/search?q=Postural+Orthostatic+Tachycardia+Syndrome. Heart rate, rhythm & blood pressure are controlled from our brain & results, not cause(s), are observed.