<s>[INST] i am 50 year old male, smoker, i have had most of my life occasional fluttering and when i feel my pulse, it will skip a beat or two. as i have gotten older the episodes of rapid pulse then skipping beats have increased. my hdl and ldl levels normal, so are stress test, i even had a heart cath, and even though i was told only thing found was "minor" plaque(and told to take simvastatin, which i am not sure i want to do that what with the side effects being what they are)what would cause these palpitations and skipping beats? [/INST] Hello there I have read through your question, and it seems to me that you are having Arrhythmia. It is caused due to defect in the functioning of the pacemaker of the heart. It can be detected on 24 hour holder monitoring. Hi you are having Arrhythmia you will need to take anti arrhythmic or get a pacemaker inserted depending on the severity of your condition. Also, please quit smoking as it will aggravate your condition and also increases plaque formation in arteries. Simvastatin is used to control cholesterol levels and do not have any side effects. I hope that answers your question. If you have any further questions please feel free to contact. </s>