Pac's

what exactly  are  PAC's ?

[va_tony]

PACs = Premature atrial contractions (PACs)

These are a type of premature heart beat starting in the atria (upper two chambers of the heart),  These are harmless but are sometimes felt as a heart thud or palpitation (although many people are completely unaware of them). This is caused by abnormal cells in the atrium or pulmonary veins starting to electrically fire before the normal heart beat is supposed to occur. This causes the atria to contract before they should. If you are taking your pulse when it happens, it feels like a beat is missing (actually, there is an extra beat but it's so weak that it's hard to feel). The next regular beat causes the thud feeling.