
Key Takeaways
In a typical heart rhythm, the heart beats in an even pattern. The top part of the heart (atrium) squeezes, and then the bottom part of the heart squeezes in a regular rhythm. However, sometimes the atrium can beat slightly out of rhythm. This is known as a premature atrial complex (PAC) or atrial premature beat.
Trigeminy is a type of abnormal heart rhythm that resembles a three-beat pattern, occurring when a beat comes early and the heart contracts sooner than expected. The early contraction causes a premature or extra heartbeat that disrupts the normal rhythm.
How to Spot Atrial Trigeminy on Your Watch ECG
Atrial trigeminy consists of two sinus beats followed by a premature atrial complex for 3 or more consecutive cycles.
Characteristics of atrial trigeminy:
- Rhythm: Irregular
- Rate: Depends on the underlying rate
- P wave: Premature, varies in size and shape
- QRS: Normal (0.08-0.12)


Common Symptoms of Atrial Trigeminy
Most people with atrial trigeminy don’t have symptoms with their heart rhythm. They may go their entire lives having occasional or constant episodes of trigeminy and never know it. However, sometimes a person may have symptoms related to this heart rhythm. They may feel as if their heart is fluttering in their chest. Other symptoms a person may experience with atrial trigeminy include:
- chest pain
- shortness of breath
- syncope (feeling faint, especially when standing up)

Any Cause for Concern?
In some people with known heart disease or heart problems, atrial trigeminy can be a concern because the heart may be more likely to go into a harmful heart rhythm. Examples include:
- atrial fibrillation
- ventricular fibrillation
- ventricular tachycardia
These heart rhythms affect the heart’s ability to pump blood effectively throughout the body. At their most severe, these heart rhythms could damage the heart and lead to cardiac arrest.
As always, if you show signs of a potential atrial trigeminy, contact your healthcare provider as soon as possible to rule out the presence of harmful underlying conditions.
Still Not Sure How to Spot Atrial Trigeminy on Your Watch ECG?
Your smartwatch can be your partner in looking after your heart. If you’re concerned about atrial trigeminy, get your smartwatch ECGs analyzed by experts within minutes on the QALY app: iOS and Android.
Human experts review your ECGs within minutes

Get peace of mind from personalized, human interpretations

All ECGs reviewed by cardiographic technicians

Join 40K+ heart heroes signed-up with QALY