Multifocal atrial tachycardia
Also called MAT.
Fast and irregular, with P waves of at least three different shapes and a PR interval that changes with them. Classically tied to severe COPD.
How to identify Multifocal atrial tachycardia
- Rate
- Over 100
- Rhythm
- Irregular
- P waves
- At least three different shapes
- PR interval
- Varies with the P wave
- QRS
- Under 0.12 s
- Clincher
- Fast and irregular with P waves of at least three shapes.
- Common causes
- Classically severe COPD.
Rhythms it gets mistaken for
Multifocal atrial tachycardia vs Atrial fibrillation
Multifocal atrial tachycardia has P waves of at least three different shapes. With A-fib you would see no P waves, only a wavy, chaotic baseline. It also has a rate over 100/min, while A-fib would show a rate of 60-100/min. How to spot A-fib: Irregularly irregular: no two R-R intervals match.
Multifocal atrial tachycardia vs Atrial fibrillation with rapid ventricular response
Multifocal atrial tachycardia has P waves of at least three different shapes. With A-fib with RVR you would see no P waves, only a wavy, chaotic baseline. How to spot A-fib with RVR: Irregularly irregular and fast. March out the R-R intervals, the irregularity hides at speed.
Multifocal atrial tachycardia vs Sinus tachycardia
Multifocal atrial tachycardia has P waves of at least three different shapes. With sinus tachycardia you would see one upright P wave before every QRS, all the same shape. It also has a PR interval that changes with the P wave, while sinus tachycardia would show a normal PR interval of 0.12-0.20 s. It also has an irregular rhythm with no pattern to the R-R intervals, while sinus tachycardia would show a regular rhythm. It starts in the atria, not the SA node: an atrial rhythm. How to spot sinus tachycardia: A normal sinus complex, just fast.
Treatment by certification level
Open your level. Treat the patient, not the strip.
Paramedic
Stable
Treat the patient and the cause behind it.
- Classically severe COPD: support the breathing problem.
- Cardioversion does not work on MAT, even in the unstable patient. The fix is the cause behind it.
- Oxygen titrated to the patient's own baseline, with 88-92% as the working target in COPD. Hypoxia is still corrected.
- Monitor and transport.
Unstable
Treat the patient and the cause behind it.
- Classically severe COPD: support the breathing problem.
- Cardioversion does not work on MAT, even in the unstable patient. The fix is the cause behind it.
- Oxygen titrated to the patient's own baseline, with 88-92% as the working target in COPD. Hypoxia is still corrected.
- Monitor and transport.
AEMT
Stable
Pulse present and stable.
- Oxygen only if hypoxic or short of breath, IV access, monitoring.
- Acquire and transmit a 12-lead ECG. Interpreting it is a Paramedic skill.
- Transport and reassess. Request a paramedic if the patient worsens.
Unstable
Unstable with a pulse.
- Oxygen if hypoxic, IV access, close monitoring.
- Expedited transport, with a paramedic intercept if that is genuinely faster than reaching the hospital.
Synchronized cardioversion and pacing are Paramedic-only, so the AEMT has no electrical option for a patient with a pulse. Never put the AED on this patient.
EMT
Stable
Pulse present: assess and support.
- Treat the patient, not the rhythm name: airway, breathing, circulation, vital signs.
- Oxygen if the SpO2 is under 94%, the patient is short of breath, or shows signs of shock.
- Request ALS and transport promptly. Reassess on the way.
An AED goes only on a patient who is unresponsive, not breathing and pulseless. It cannot feel a pulse, so on a patient with a pulse it can advise a shock that would do harm.
Unstable
Pulse present but poorly perfusing: this patient needs ALS fast.
- Treat the patient, not the rhythm name: airway, breathing, circulation, vital signs.
- Oxygen if the SpO2 is under 94%, the patient is short of breath, or shows signs of shock.
- Request ALS and transport promptly. Reassess on the way.
An AED goes only on a patient who is unresponsive, not breathing and pulseless. It cannot feel a pulse, so on a patient with a pulse it can advise a shock that would do harm.