Premature atrial contraction

Premature atrial contractions (PACs) are a type of premature heart beat, irregular heart beat or benign arrhythmia which start in the upper two chambers of the heart, also called atria. These aren't as serious as a Premature Ventricular Contraction and usually require no medical care. Individuals with the condition may report feeling that his or her heart "stops" after a symptom. PVCs are also called heart palpitations (although there are many other forms of arrhythmia).

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In many cases doctors are unable to determine a cause. Some cells in the heart (ectopic foci) start to fire or go off before the normal heart beat is supposed to occur in the SA node. These can be cells that are damaged or sick from a virus, or from some other cause that a doctor can't determine, many times, doctors don't know why they happen. Sometimes people who have them feel a skipped beat or a thump in their chest or neck. In many cases, the person feels nothing.

Usually a doctor will do or order an EKG, Holter, or Cardiac Event Monitor for the person to wear. Without an EKG, it is impossible to determine the existence of PACs or whether they aren't a PAC at all. Once proven, the person may be referred to a cardiologist for further testing to determine whether the heart is damaged or deteriorated. In the case that it isn't, sometimes simple lifestyle changes can alter and/or prevent the occurances of PAC's. Exercising, eating right, and lowering stress levels are the most effective ways of reducing the occurences.

In rare cases, a PAC can, like a PVC, trigger a more serious arrhythmia such as Atrial flutter or fibrillation. This is seldom seen in a healthy heart, but in a case that it does happen, medical attention should be sought to see what might have caused the problem and what steps can be taken to fix it. Unlike PVC's, PAC's generally do not compromise the hemodynamic system because the conduction throughout the AV node, and the ventricles of the heart are activated in a normal sequence. a PAC usually will also on the EKG be characterized by: - a normal QRS complex - a normal T wave repolarization (not inverted to the other T waves) - an odd, mis-shapen P wave depolarization

See also

• Premature ventricular contraction