I can only tell you that tachycardia and other arhythmia events are often preceded by PVC's (skipped beats).
Best of luck,,,
If you have a normal EKG and structurally normal heart, the chance that the heart rhythm you describe is dangerous is very low -- the same as anyone in the general population with a structurally normal heart. There is no way to know for sure what the rhythm was without seeing it on a monitor.
Sustained ventricular tachycardia is very rare. It is also not dangerous in people with structurally normal hearts. The likelihood that it was an SVT (sinus tachycardia included in the diagnosis of SVT) versus is VT extremely favors SVT. Sustained VT with structurally normal hearts is very rare.
It is worth talking to your doctor about a monitor to see if you can capture an event. Fortunately and unfortunately, if this is the frst time it ever happened, it is unlikely that a 30 day event monitor will capture the rhythm.
Talk to your doctor about what steps should be taken next, but the likey answer is a 30 day event monitor.
I hope this helps.