Focal atrial tachycardia is a regular fast rhythm that starts from one irritable spot in the atria outside the sinus node, usually at 100 to 250 beats per minute. It can be brief and harmless, but if it lasts for weeks it can weaken the heart (tachycardia-induced cardiomyopathy).
Key symptoms
- Palpitations, often starting and stopping gradually
- Lightheadedness
- Shortness of breath
- Fatigue
- Sometimes no symptoms
What you find on exam
- Regular fast pulse
- Blood pressure and signs of poor perfusion
- Look for lung disease; multifocal atrial tachycardia is common in COPD
- Signs of heart failure if it has lasted long
- Check for digoxin use, a known trigger
Tests
- 12-lead ECG: narrow QRS with P waves of a different shape before each QRS
- Holter or event monitor for episodes that come and go
- Electrolytes, magnesium, thyroid tests, digoxin level if taking it
- Echocardiogram to check pump function
Treatment basics
- Unstable patient: synchronized cardioversion
- Adenosine may stop some focal atrial tachycardias and helps clarify the diagnosis
- Rate control with a beta blocker or diltiazem
- Catheter ablation for recurrent or persistent episodes
- Treat causes: low potassium or magnesium, digoxin toxicity, lung disease
Red flags
- Low blood pressure, chest pain or fainting
- Signs of heart failure
- Known digoxin use with nausea or vision changes
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.