Understanding PACs: Causes, Symptoms & Risks

Have you ever felt your heart flutter, skip a beat, or suddenly pound for a moment? For many people, this fleeting sensation is caused by something called a Premature Atrial Contraction (PAC) — a common type of irregular heartbeat. While PACs are often harmless, frequent or persistent PACs can sometimes indicate deeper cardiac issues, making awareness and monitoring crucial.

Here, we’ll explore:

• What PACs are
• What do they feel like
• What causes them
• When they may become serious
• How continuous ECG can help

What Are Premature Atrial Contractions (PACs)?

PACs are early heartbeats that originate in the atria, the heart’s upper chambers, before the heart’s natural pacemaker (the sinoatrial node) fires. This disrupts the normal rhythm — often followed by a brief pause — which may feel like a skipped or extra-strong heartbeat.

Real-World Example: When PACs Are More Than Just a Nuisance

In a recent case published in HeartRhythm Case Reports, a 38-year-old woman experienced persistent palpitations due to an unusually high burden of premature atrial contractions (PACs). Despite initial conservative treatment, her symptoms worsened, and imaging revealed impaired left ventricular function. Electrophysiological evaluation confirmed the PACs as the underlying cause. She underwent catheter ablation, after which her heart function and symptoms significantly improved, highlighting that frequent PACs, while often benign, can sometimes lead to reversible cardiomyopathy if left untreated.

This example underscores why it’s essential to understand and track your heart rhythm, especially if symptoms persist.

What Do PACs Feel Like?

PACs can vary in how they’re experienced:

• A fluttering sensation
• A skipped or forceful heartbeat
• Shortness of breath or anxiety
• Or no sensation at all

They’re often more noticeable when lying down or at rest. While many people live with occasional PACs without concern, frequent PACs can signal underlying instability in the heart’s electrical system.

Common Triggers and Risk Factors

PACs may be caused or worsened by:

• Caffeine, alcohol, or nicotine
• Stress, anxiety, or lack of sleep
• Electrolyte imbalances (like low potassium or magnesium)
• Dehydration
• Certain medications
• Underlying heart or lung conditions (like COPD or heart failure)

You’re more likely to experience PACs if you’re older, sedentary, pregnant, have high blood pressure, low HDL (“good”) cholesterol, or live with chronic illness.

When Should You Be Concerned?

PACs are generally benign, but medical evaluation is recommended if:

• They happen frequently or in clusters
• You feel dizzy, faint, fatigued, or have chest discomfort
• You have a history of atrial fibrillation (AFib) or other arrhythmias
• Your quality of life or sleep is affected

High PAC burden (i.e., frequent PACs) is associated with:

• Increased risk of AFib
• Greater likelihood of ischemic stroke
• Progression to heart failure or reduced cardiac output

Diagnosing and Monitoring PACs

PACs are often missed during routine ECGs since they may not occur during a short snapshot. That’s where continuous or ambulatory ECG  becomes valuable.

Key Tools Used to Diagnose PACs:

• Electrocardiogram (ECG)
• Holter monitor (24–48 hours)
• Echocardiogram
• Blood tests (to check electrolytes or thyroid function)

But even Holters can miss intermittent Premature Atrial Complexes. For better detection and diagnosis, long-term, wearable ECG devices offer a major advantage.

Why Continuous Monitoring Matters

With continuous ECG-based heart rate monitors, you and your doctor can:

• Catch early signs of arrhythmias
• Track patterns or triggers (like stress or caffeine)
• Reduce anxiety by understanding what’s happening with your heart
• Avoid unnecessary clinic visits through remote medical review
• Make informed decisions about lifestyle changes or treatments

Read more: 24×7 Continuous ECG: The Future of Personalized Heart Health Management

When to Seek Immediate Medical Help

You should seek urgent care if Premature Atrial Complexes are accompanied by:

• Chest pain or pressure
• Persistent shortness of breath
• Fainting or extreme fatigue
• A rapid or irregular heartbeat lasting over 30 minutes

Even if PACs are usually harmless, it’s better to rule out serious conditions early.

Final Thoughts

Premature Atrial Contractions are often a normal part of your heart’s rhythm, but if they become frequent or symptomatic, they deserve attention. With modern continuous ECG monitoring technology, you can take control of your heart health from the comfort of your own home.

Whether you’re investigating palpitations or managing a known arrhythmia, understanding your heart’s rhythm is the first step toward peace of mind and proactive care.

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