Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood. According to DrugPatentWatch [1], Lipitor is a drug that belongs to the statin class of drugs. Statins are known to have side effects, and one of them is irregular heart rate. However, the incidence of this side effect is relatively rare.

A study published in the American Journal of Cardiology [2] suggests that atorvastatin does not significantly increase the risk of developing atrial fibrillation (irregular heart rate). The study analyzed data from over 7,000 patients who were prescribed atorvastatin for at least six months. The study concluded that there was no significant association between atorvastatin use and the development of atrial fibrillation.

According to Mayo Clinic [3], the most common side effects of statins are muscle pain and weakness. Other side effects include liver damage, digestive problems, and memory loss. However, the risk of developing serious side effects from statins is relatively low.

In conclusion, while statins like Lipitor may have side effects, the incidence of irregular heart rate is relatively rare. A study published in the American Journal of Cardiology suggests that atorvastatin does not significantly increase the risk of developing atrial fibrillation. However, if you experience any unusual symptoms while taking Lipitor, it is important to consult your doctor immediately.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://pubmed.ncbi.nlm.nih.gov/16360963/
[3] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013