STEPUP Cardiovascular System: Tachyarrhythmias - Multifocal Atrial Tachycardia

Question 1

In which patients does multifocal atrial tachycardia usually occur in?

Answer 1

Patients with severe pulmonary disease (e.g., COPD)

Question 2

What are ECG findings for multifocal atrial tachycardia? What is required on ECG to make an accurate diagnosis?

Answer 2

1) Variable P-wave morphology and variable PR and RR intervals
2) At least three different P-wave morphologies are required to make an accurate diagnosis

Question 3

What is the only difference between the diagnosis of multifocal atrial tachycardia and wandering atrial pacemaker?

Answer 3

The diagnosis of wandering atrial pacemaker is identical except that the heart rate is between 60 and 100 bpm (i.e., not tachycardic)

Question 4

How else can the diagnosis of multifocal atrial tachycardia be made aside from EKG?

Answer 4

Use of vagal maneuvers or adenosine to show AV block without disrupting the atrial tachycardia

Question 5

What is the treatment of multifocal atrial tachycardia directed against? If ventricular function is preserved, what are acceptable medical treatment? If LV function is not preserved, what should you use instead? What about electrical cardioversion?

Answer 5

1) It is directed at the underlying disease, improving oxygenation and ventilation (strong association between MAT and lung disease)
2) Calcium channel blockers, beta-blockers, digoxin, amiodarone, IV flecainide, and IV propafenone
3) Use digoxin, diltiazem, or amiodarone
4) Electrical cardioversion is ineffective and should not be used