The arrhythmia known as SVT has several categories, and among them are flutter and atrial fibrillation. Most patients don't feel flutter, or aren't so annoyed by it that it prevents them from focusing on other business and interests. Atrial fibrillation is a whole 'nuther animal. There are many who also don't feel AF, at least not enough for them to stop what they like doing and to do something about it. But for people like me, it's almost a show stopper. I also felt a bit anxious, sometimes short of breath, feeling like I might keel over. The incessant thumping in my chest wall was what really put me off. I couldn't sleep on my left side because my AF would start within seconds. On my back or on my right side were usually calming...oddly.

It is possible you are becoming more sensitized to the symptoms, maybe because they're more frequent, maybe you're health is iffy in one or more respects so far undiagnosed, you are under more stress....you can figure that out for yourself. However, heart arrhythmias are indications of diseased substrate...the tissue under the endothelium lining each of the four chambers. They can be indications of malfunctioning valves, of fibrosis and collagen deposition from stretching that happens when one side of the heart, or one of the chambers, is 'blown out' by the pressures of the others. Hypertension, as an example, can cause atrial enlargement, even when the arrhythmia is well controlled.

What I am getting at is that your heart lives, and it moves through time, just like the rest of your body and organs. Over time, it changes, and it might not be for the better...especially if it's already disordered, which yours...and mine...are. Your brand of SVT may be premature atrial complexes or they may now be atrial fibrillation. It's not unheard of for hearts to develop multiple foci for re-entering and vortex/rotor signals that can keep a hear muscle contracting in ways that are both counterproductive and awful in how they feel.

Bottom line, if this is new, and it might be new to a specialist, you really should apprise that person. Consult an expert and get them behind you in your struggle to control whichever condition or arrhythmia you have.