From the Guidelines
Premature atrial complexes (PACs) are generally benign and do not require further evaluation or therapy in the absence of structural heart disease and thyroid dysfunction, with no or only mild symptoms. PACs are early heartbeats that originate in the atria rather than from the normal pacemaker of the heart, the sinoatrial node. These extra beats occur when an area of the atrial tissue becomes irritable and fires an electrical impulse before the normal heartbeat would occur. According to the European Society of Cardiology, a careful history, physical examination, and ECG should be performed to assess PACs 1.
Key Points to Consider
- PACs are common and usually benign, occurring in healthy individuals of all ages
- Most people with PACs don't experience symptoms, but some may feel palpitations, skipped beats, or a fluttering sensation in the chest
- PACs typically don't require treatment unless they cause significant symptoms or occur very frequently
- For symptomatic patients, avoiding triggers like caffeine, alcohol, and stress may help reduce episodes
- In more severe cases, medications might be prescribed to suppress the abnormal beats, but this is not typically necessary for asymptomatic individuals, as stated in the consensus document from the European Society of Cardiology 1.
Monitoring and Prevention
PACs are important to monitor as frequent PACs may increase the risk of developing atrial fibrillation in some individuals. The underlying mechanism involves enhanced automaticity, triggered activity, or reentry circuits in the atrial tissue that disrupt the normal heart rhythm. However, for individuals with no or only mild symptoms and no underlying structural heart disease, no further evaluation or therapy is required, as recommended by the European Society of Cardiology 1.
From the Research
Definition and Prevalence of Premature Atrial Complexes
- Premature atrial complexes (PACs) are a type of arrhythmia that occurs in nearly all individuals, as stated in the study 2.
- PACs are typically asymptomatic but can cause palpitations, and frequent PACs are associated with an increased risk of developing atrial fibrillation 2.
Treatment and Management of Premature Atrial Complexes
- Symptomatic PACs can be treated with beta blockers after potentially reversible causes, such as electrolyte abnormalities and hyperthyroidism, are eliminated 2.
- Beta blockers have been shown to reduce PAC symptoms and improve long-term outcomes, including a decrease in mortality rates, as demonstrated in the study 3.
- The antiarrhythmic mechanisms of beta blocker therapy involve the modulation of cardiac rhythm by reducing sympathetic activity, which can lead to disturbances of the heart rhythm 4.
Association with Other Heart Conditions
- PACs are associated with an increased risk of adverse cardiovascular outcomes, including atrial fibrillation and stroke, although beta blockers may not reduce the risk of these events 3.
- Premature ventricular contractions (PVCs) are also common and can be associated with underlying heart disease, which can be detected using an echocardiogram 2.