Premature atrial contraction

Premature Atrial Contraction (PAC)

Premature Atrial Contraction (PAC) is a common cardiac arrhythmia characterized by early heartbeats originating in the atria, the upper chambers of the heart. These early beats occur before the heart's regular rhythm and are often described by individuals as feeling like the heart has "skipped a beat."

Definition

PACs are extra heartbeats that disrupt the regular, rhythmic beat of the heart. They arise from the atrial muscles firing an electrical impulse prematurely. While generally considered benign, frequent PACs can be indicative of underlying heart conditions or risk factors for more serious arrhythmias.

An electrocardiogram showing a Premature Atrial Contraction.

Causes

The exact cause of PACs can vary, encompassing a range of factors including:

• Stress
• Fatigue

• Caffeine and alcohol consumption
• Smoking
• Certain medications
• Underlying heart disease

Symptoms

Many individuals may not experience any symptoms, while others might feel palpitations or an uncomfortable sensation of the heart skipping a beat. Symptoms are typically fleeting and do not cause lasting discomfort.

Diagnosis

Diagnosis primarily involves the use of an Electrocardiogram (ECG) or Holter monitor to detect the premature beats. The presence of PACs is identified by a premature P wave followed by a QRS complex on the ECG.

A patient wearing a Holter monitor for continuous ECG monitoring.

Treatment

Treatment for PACs is often unnecessary unless they are symptomatic or indicative of an underlying heart condition. In such cases, treatment focuses on the underlying cause. Lifestyle modifications and, in some cases, medication may be recommended to reduce the frequency of PACs.

Lifestyle Modifications and Management

Advising patients to reduce caffeine intake, quit smoking, and manage stress are common recommendations for those experiencing frequent PACs. Regular monitoring and follow-up with a healthcare provider are essential for individuals with persistent symptoms or those with underlying heart conditions.

Implications

While PACs are generally benign, frequent occurrences can increase the risk of developing atrial fibrillation, a more serious form of arrhythmia. Monitoring and managing risk factors are crucial for individuals with frequent PACs.

External Links

• American Heart Association
• Mayo Clinic - Heart Arrhythmia

References

• Cardiac Arrhythmias: Practical Notes on Interpretation and Treatment by David H. Bennett
• Clinical Cardiology: Current Practice Guidelines by Demosthenes G. Katritsis, A. John Camm, and Bernard J. Gersh

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