Multifocal atrial tachycardia
| Multifocal atrial tachycardia | |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Synonyms and keywords: MAT
Overview
Multifocal atrial tachycardia is a cardiac arrhythmia, specifically a type of supraventricular tachycardia. It is characterized by an electrocardiogram (ECG) strip with 3 or more P-waves of variable morphology and varying P-R intervals, plus tachycardia, which is a heart rate exceeding 100 beats per minute.
The P-waves and P-R intervals are variable due to a phenomenon called wandering atrial pacemaker (WAP). The electrical impulse is generated at a different focus within the atria of the heart each time. WAP is positive once the heart generates at least three different P-wave formations from the same ECG lead. Then, if the heart rate exceeds 100 beats per minute, the phenomenon is called multifocal atrial tachycardia. It is mostly common in patients with lung disorders, but it can be occur after acute MI, hypokalemia, and hypomagnesemia. It is sometimes associated with digitalis toxicity in patients with heart disease. Its rate can be reduced by administering verapamil.
Causes
Multifocal atrial tachycardia usually results from an underlying medical condition such as COPD, chronic renal failure, pulmonary embolism, electrolyte imbalance, and many other conditions.
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
- Aminophylline toxicity
- Congestive heart failure
- Hypokalemia
- Hypoxia
- Myocardial infarction
- Pulmonary embolism
- Sepsis
Common Causes
- Chronic obstructive pulmonary disease
- Chronic renal failure
- Congestive heart failure
- Diabetes mellitus
- Hypokalemia
- Hypoxia
- Myocardial infarction
- Pneumonia
- Pulmonary embolism
- Sepsis
Causes by Organ System
| Cardiovascular | Congestive heart failure, myocardial infarction, valvular heart disease |
| Chemical/Poisoning | No underlying causes |
| Dental | No underlying causes |
| Dermatologic | No underlying causes |
| Drug Side Effect | Aminophylline, isoproterenol, theophylline |
| Ear Nose Throat | No underlying causes |
| Endocrine | Diabetes mellitus |
| Environmental | No underlying causes |
| Gastroenterologic | No underlying causes |
| Genetic | No underlying causes |
| Hematologic | No underlying causes |
| Iatrogenic | Postoperative complication |
| Infectious Disease | Pneumonia, sepsis |
| Musculoskeletal/Orthopedic | No underlying causes |
| Neurologic | No underlying causes |
| Nutritional/Metabolic | No underlying causes |
| Obstetric/Gynecologic | No underlying causes |
| Oncologic | Lung cancer |
| Ophthalmologic | No underlying causes |
| Overdose/Toxicity | Aminophylline |
| Psychiatric | No underlying causes |
| Pulmonary | Chronic obstructive pulmonary disease, hypoxia, lung cancer, pneumonia, pulmonary embolism |
| Renal/Electrolyte | Chronic renal failure, hypokalemia, hypomagnesemia |
| Rheumatology/Immunology/Allergy | No underlying causes |
| Sexual | No underlying causes |
| Trauma | No underlying causes |
| Urologic | No underlying causes |
| Miscellaneous | No underlying causes |
Causes in Alphabetical Order
Diagnosis
Electrocardiography
- There are P waves of varying morphology from at least three different foci
- There is absence of one dominant atrial pacemaker
- Variable PP intervals, RR intervals, and PR intervals
- Atrial rate is above 100 beats per minute (bpm)
- Can be mistaken for atrial fibrillation if the p waves are of low amplitude
- High incidence in the elderly and in those with COPD
References
Additional resources
Examples
