Just a bit of information: The normal heart has a regular rate and rhythm, usually (except in athletes) between 60 and 100 bpm. This rhythm is initiated in a single focus in the right atrium, called the sinus node. The signal that starts the heartbeat is caused by a gradual leak of ions into the cell, until an electrical potential is built up that causes the cell to "fire". What's unique about the sinus node is that this process occurs faster there than in other heart muscle cells, but all the cells in the heart have the ability to fire and start a contraction.

An irregular heartbeat can be caused by quite a few things. Some people have a rhythm that varies with their breathing -- as they inhale, the pressure in their chest drops, drawing more blood back to the heart, and the heart speeds up as a result, and slows down on exhalation. That's called sinus arrhythmia, and unless it indicates dehydration, it's totally benign. Other people have an occasional extra beat that comes from somewhere other than the sinus node -- these are termed premature atrial or ventricular contractions, depending on where the overly busy cell that's initiating the beat is living. In the vast majority of cases, these are totally benign as well (the exception is when they are due to something which is damaging heart muscle).

On the other hand, there is atrial fibrillation, which is probably the most common cause of irregular heartbeat. In atrial fib, the sinus node is being drowned out by uncoordinated electrical activity in the atrium -- It's the difference between the speaker addressing the crowd, and the crowd jabbering excitedly and drowning out the speaker. At intervals, one of these random signals makes it through the electrical "gate" between the atria and the ventricles, and causes a ventricular contraction. This doesn't occur regularly, so the rhythm jumps around. Depending on the health of the conducting system, the heart rate in Afib can be extremely fast -- if it is slow, in the absence of medications, it suggests the conducting system isn't healthy, either. Afib can be caused by circulatory damage to the heart, but more commonly is due to dilation of the atria from heart failure or valvular abnormalities -- or sometimes just from age. Sometimes there is one area that is setting up the chaos, and it can be ablated, and the rhythm returned to normal for long periods of time.

Until an electrocardiogram is done and the precise nature of the irregular rhythm is known, there is very little that can be said about possible treatment or prognosis. But PACs and PVCs are very common, so unless you are older, or have a history of some kind of cardiac issue already, there's a good likelihood that all of this will prove to be a tempest in a teapot.