From the Guidelines
Treatment for multifocal atrial tachycardia (MAT) primarily involves addressing underlying conditions and utilizing pharmacological interventions. The first-line treatment is management of the underlying condition, such as pulmonary disease, pulmonary hypertension, coronary disease, and valvular heart disease, as well as hypomagnesemia and theophylline therapy 1.
Key Treatment Strategies
- Intravenous magnesium may also be helpful in patients with normal magnesium levels 1.
- Antiarrhythmic medications in general are not helpful in suppression of MAT, but verapamil has been shown to have some efficacy in slowing conduction at the AV nodal level to control heart rate 1.
- Metoprolol is reasonable for ongoing management in patients with recurrent symptomatic MAT, but should be avoided in patients with severe conduction abnormalities or sinus node dysfunction 1.
Pharmacological Interventions
- Verapamil, 2.5-5 mg intravenously every 15-30 minutes, may be administered to slow the ventricular response 1.
- Metoprolol, 25-50 mg orally every 6-8 hours, may be used to slow the ventricular rate in MAT, but should be avoided in patients with severe underlying pulmonary disease, particularly those with bronchospasm 1.
- Magnesium sulfate, 1-2 grams intravenously over 10-15 minutes, may be used to help control the arrhythmia, with repeat doses as needed 1.
Important Considerations
- Electrical cardioversion is not useful in MAT and should not be considered as a treatment option 1.
- Beta blockers and verapamil should be avoided in patients with acute decompensated heart failure and/or hemodynamic instability 1.
From the Research
Treatment Options for Multifocal Atrial Tachycardia (MAT)
The treatment for MAT includes:
- Pharmacologic treatment to control the heart rate and rhythm
- Correction of underlying conditions such as hypoxia, congestive heart failure, and theophylline toxicity 2
- Medications such as metoprolol, verapamil, and amiodarone have been used to treat MAT
Medications Used to Treat MAT
Some of the medications used to treat MAT include:
- Metoprolol: a beta-adrenergic blocking agent that has been shown to be effective in converting MAT to sinus rhythm 3, 4
- Verapamil: a calcium channel blocker that has been used to treat MAT, although its effectiveness is not well established 2
- Amiodarone: an antiarrhythmic medication that has been shown to be effective in treating MAT, especially in patients with underlying lung and/or cardiac disease 5
- Propranolol: a beta-adrenergic blocking agent that has been used to slow the atrial rate in patients with MAT 6
Administration and Dosage
The administration and dosage of these medications vary:
- Metoprolol: can be administered orally or intravenously, with a mean oral dose of 32.5 mg and a mean intravenous dose of 6.5 mg 4
- Amiodarone: can be administered intravenously or orally, with a dosage of 450-900 mg over 2 hours for intravenous administration and 600 mg/day for oral administration 5
- Propranolol: the dosage is not specified in the studies, but it has been shown to be effective in slowing the atrial rate in patients with MAT 6