The most common SVT is AVNRT (~60%), followed by AVRT (~30%), and Atrial Tachycardia (~10%).
AVNRT is more common in women (~70%), mean age of onset is 32 years
AVRT is more common in men, mean age of onset 23 years
Atrial Tachycardia is more common with older age and structural heart disease
Common symptoms of SVT include palpitations with bounding neck pulsations, exertional fatigue, dyspnea, chest discomfort, and pre-syncope (rarely syncope).
Management of SVT includes vagal maneuvers followed by adenosine (6mg IV push followed by 20cc of NS) through a peripheral line. (If using a central line, the dose is lower).
For unstable SVT, management includes synchronized cardioversion.
A modified Valsalva maneuver was shown to be more effective than the traditional Valsalva maneuver (Appelboam, Andrew, et al. “Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial.” The Lancet 386.10005 (2015): 1747-1753) which includes placing the patient supine and doing a passive leg raise in addition to the Valsalva.