MULTIFOCAL ATRIAL TACHYCARDIA
Overview
● A rapid, irregular atrial rhythm arising from multiple ectopic foci within the atria.
● Most commonly seen in patients with severe COPD or congestive heart failure.
● It is typically a transitional rhythm between frequent premature atrial complexes (PACs) and atrial
flutter / fibrillation.
Electrocardiographic Features
● Heart rate > 100 bpm (usually 100-150 bpm; may be as high as 250 bpm).
● Irregularly irregular rhythm with varying PP, PR and RR intervals.
● At least 3 distinct P-wave morphologies in the same lead.
● Isoelectric baseline between P-waves (i.e., no flutter waves).
● Absence of a single dominant atrial pacemaker (i.e., not just sinus rhythm with frequent PACs).
● Some P waves may be non-conducted; others may be aberrantly conducted to the ventricles
● When the heart rate is less than 100 beats per minute, the arrhythmia is called "wandering atrial
pacemaker."
Causes of MAT
MAT is most common in people age 50 and over. It is often seen in people with conditions that lower the
amount of oxygen in the blood. These conditions include:
• Bacterial pneumonia
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure
• Lung cancer
• Lung failure
• Pulmonary embolism
Overview
● A rapid, irregular atrial rhythm arising from multiple ectopic foci within the atria.
● Most commonly seen in patients with severe COPD or congestive heart failure.
● It is typically a transitional rhythm between frequent premature atrial complexes (PACs) and atrial
flutter / fibrillation.
Electrocardiographic Features
● Heart rate > 100 bpm (usually 100-150 bpm; may be as high as 250 bpm).
● Irregularly irregular rhythm with varying PP, PR and RR intervals.
● At least 3 distinct P-wave morphologies in the same lead.
● Isoelectric baseline between P-waves (i.e., no flutter waves).
● Absence of a single dominant atrial pacemaker (i.e., not just sinus rhythm with frequent PACs).
● Some P waves may be non-conducted; others may be aberrantly conducted to the ventricles
● When the heart rate is less than 100 beats per minute, the arrhythmia is called "wandering atrial
pacemaker."
Causes of MAT
MAT is most common in people age 50 and over. It is often seen in people with conditions that lower the
amount of oxygen in the blood. These conditions include:
• Bacterial pneumonia
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure
• Lung cancer
• Lung failure
• Pulmonary embolism
