The rare time that PACs cause a problem is when they are so frequent in number that they risk triggering other rhythm problems. One such rhythm problem is atrial fibrillation (AF). AF is usually recognized by a change in the pattern of palpitations from skips and bumps to a persistent fluttering that lasts for minutes to sometimes days. If such a change in the palpitations occurs, the rhythm should be evaluated again right away. AF can lead to stroke if it is left untreated for over 24-48 hours.
In the case of PVCs, the rare time that they cause a problem is when they are so frequent in number that they start to weaken the heart muscle. It is currently felt that if the overall burden of PVCs is over 10-20 percent of all your heart beats, then the risk of muscle damage starts to rise. A 24-hour Holter ECG monitor can be worn to figure out what the PVC burden is, and sometimes this test is repeated periodically to monitor the burden of PVCs over time. Catheter ablation of the spot in the heart where the PVC is coming from has been shown to prevent and even reverse muscle damage from excessive PVCs.
Finally, even though PACs and PVCs are most often safe, they can be quite disruptive. The palpitations can sometimes become so bothersome that they prevent proper sleeping. Some people will start avoiding physical activities - like exercising - because it can worsen the palpitations. Concern for these abnormal beats can lead to anxiety and mood problems. When palpitations interfere with life, even if they are not technically dangerous, they are a problem that needs treatment. There are medications such as beta-blockers or calcium-channel blockers that can be effective. It is not unusual to try a number of different medications, at differing doses, before you get suppression of the palpitations. Catheter ablation of the premature focus in the heart can also be an effective and safe way to eliminate palpitations from PACs and PVCs.