From the Guidelines
Premature Atrial Contractions (PACs) are extra heartbeats that originate in the atria, occurring before the normal heartbeat, and are generally harmless and common in healthy individuals. These early beats happen when an area in the atria outside the normal pacemaker (sinoatrial node) fires an electrical impulse 1. PACs can be triggered by various factors such as caffeine, alcohol, stress, fatigue, or certain medications. Most people with PACs do not require treatment as they are often asymptomatic and benign. However, if PACs are frequent or bothersome, lifestyle modifications like reducing caffeine and alcohol intake, managing stress, and getting adequate sleep may help reduce their occurrence.
Key Characteristics of PACs
- They are extra heartbeats that occur before the normal heartbeat
- They originate in the atria, outside the normal pacemaker (sinoatrial node)
- They can be triggered by caffeine, alcohol, stress, fatigue, or certain medications
- They are generally harmless and common in healthy individuals
- They may be felt as a skipped beat, flutter, or momentary pause followed by a stronger beat
Management of PACs
- Most people with PACs do not require treatment
- Lifestyle modifications may help reduce the occurrence of PACs, such as:
- Reducing caffeine and alcohol intake
- Managing stress
- Getting adequate sleep
- In some cases, medications such as beta-blockers or calcium channel blockers might be prescribed if PACs are very frequent or causing significant symptoms 1.
It is essential to note that while PACs are generally benign, it is crucial to distinguish them from other types of arrhythmias, such as supraventricular tachycardias, which may require different management approaches 1. A clinical history describing the pattern of PACs, including the number of episodes, duration, frequency, mode of onset, and possible triggers, is crucial in clinical decision-making 1.
From the Research
Definition and Prevalence of Premature Atrial Contractions (PACs)
- Premature atrial contractions (PACs) are a common cardiac phenomenon where the heart experiences extra beats originating from the atria [(2,3)].
- These contractions can be associated with adverse clinical outcomes, including a higher risk of incident atrial fibrillation (AF), stroke, and all-cause mortality [(2,3)].
Pathophysiology and Clinical Implications
- The pathophysiology of PACs involves structural, functional, and biochemical changes in the atria, leading to arrhythmia occurrence and thromboembolic events [(2,3)].
- PACs can be a predictor of atrial fibrillation and a relevant marker of atrial cardiomyopathy 3.
- The concept of atrial cardiomyopathy suggests that AF would be an epiphenomenon outside the causal pathway between PACs and stroke 2.
Diagnosis and Treatment
- Diagnosis of PACs typically involves electrocardiographic findings, and treatment options include medical therapy, ablation, and lifestyle modifications [(4,5)].
- Ablation of PACs is a viable alternative to medical therapy, with a comparable safety profile and efficacy [(4,5)].
- Ultra-high-density (UHD) mapping has improved the success rate of PAC ablation 5.
Impact on Left Atrial Function
- Frequent PACs can impair left atrial contractile function and promote adverse left atrial remodeling 6.
- Patients with frequent PACs have reduced left atrial peak contractile strain and strain rates, as well as larger left atrial volume index (LAVI) compared to controls 6.
- Frequent PACs are an independent predictor of reduced left atrial peak contractile strain and strain rate 6.