From the Research
PACs (Premature Atrial Contractions) are early heartbeats that originate in the atria, occurring in nearly all individuals, and although typically asymptomatic, they can cause palpitations and are associated with an increased risk of developing atrial fibrillation. PACs happen when an area in the atria fires an electrical impulse before the sinoatrial node (the heart's natural pacemaker) has a chance to initiate the next normal heartbeat 1. They are generally benign and common, occurring in healthy individuals of all ages, though they tend to increase with age, and often cause symptoms like a skipped beat sensation, fluttering, palpitations, or a feeling that the heart is "jumping" in the chest. Some key points to consider about PACs include:
- They are associated with an increased risk of atrial fibrillation, as well as other adverse outcomes such as stroke and all-cause mortality 2, 3
- Frequent PACs (more than 100 per day) may increase the risk of developing atrial fibrillation in some individuals 2, 3
- Beta blockers may be prescribed to reduce the frequency of PACs and have been shown to decrease long-term mortality in patients with high-burden and low-burden PACs 4
- Avoiding triggers like caffeine, alcohol, stress, and fatigue can help alleviate symptoms of PACs
- PACs are important to monitor because of their potential association with atrial fibrillation and other adverse outcomes. The underlying mechanism involves abnormal electrical activity in the atria that disrupts the heart's normal rhythm momentarily before returning to the regular pattern. Recent studies suggest that PACs are not just a benign phenomenon, but rather a predictor of atrial fibrillation and a relevant marker of atrial cardiomyopathy 5. Treatment with beta blockers, such as metoprolol 25-100mg twice daily, may be recommended to reduce the frequency of PACs and improve long-term outcomes.