PAC Detection — Apple Watch ECG Analysis
Identify Premature Atrial Contractions in your Apple Watch ECG recordings. HeartLab detects PACs automatically with advanced algorithm analysis.
What Are Premature Atrial Contractions (PACs)?
PACs are extra heartbeats originating from the atria, the upper chambers of the heart. They occur when an electrical impulse fires from the atria before the normal sinus node signal. On an ECG, PACs typically appear as early beats with an abnormal P wave morphology, followed by a normal or slightly different QRS complex. PACs are extremely common and usually benign, but frequent PACs may increase the risk of developing atrial fibrillation over time. Monitoring PAC frequency helps detect potential cardiac rhythm changes early.
How HeartLab Identifies PACs
HeartLab analyzes the timing and morphology of each heartbeat in your Apple Watch ECG recordings. By examining R-R interval patterns and P wave characteristics, HeartLab can distinguish PACs from normal sinus beats and from ventricular ectopic beats (PVCs). The app counts PAC occurrences, calculates the PAC burden percentage, and identifies whether PACs occur in isolation or in patterns. This level of analysis goes far beyond what the native Apple Watch ECG app provides.
Track PACs and Protect Your Heart
Research shows that frequent PACs (more than 200 per day) may predict a higher risk of atrial fibrillation. HeartLab empowers you to track your PAC frequency over time with trend analysis, identify triggers that increase PAC occurrence, generate detailed reports for your cardiologist, and understand your results with AI-powered explanations. All this from your Apple Watch — no extra hardware, no cloud uploads, complete privacy.
FAQ
What's the difference between PACs and PVCs?
PACs originate from the atria (upper heart chambers) and typically have a narrow QRS complex, while PVCs originate from the ventricles (lower chambers) and show a wide, abnormal QRS. HeartLab detects both types.
Can PACs lead to AFib?
Research suggests frequent PACs may increase the risk of developing atrial fibrillation. Regular monitoring with HeartLab helps you track PAC frequency and share trends with your doctor.
Does Apple Watch detect PACs?
The native Apple Watch ECG app only classifies recordings as AFib, sinus rhythm, or inconclusive. It does not detect individual PACs. HeartLab adds this capability.
How many PACs per day is normal?
Most people have some PACs daily. Generally, fewer than 100 PACs per day is considered normal. HeartLab helps you count and track your PAC frequency over time.
Get Advanced ECG Analysis on Your Wrist
HeartLab delivers clinical-grade ECG analysis directly from your Apple Watch — arrhythmia detection, HRV analysis, and professional reports.
