Answer

Multifocal atrial tachycardia, precipitated by an exacerbation of chronic obstructive pulmonary disease (COPD) due to an acute respiratory infection: The patient was judiciously administered nebulized bronchodilators, intravenous antibiotics, and inhaled steroids.

His arrhythmia was treated with intravenous diltiazem, followed by oral diltiazem. These medications slowed the arrhythmia and relieved his palpitations. Neither DC cardioversion nor digoxin is effective in converting the arrhythmia to a sinus rhythm, and digoxin has not been found to be effective in controlling the ventricular rate. Furthermore, digoxin may promote the arrhythmia or lead to potentially fatal arrhythmias due to digoxin toxicity when it is administered to patients in whom atrial fibrillation is incorrectly diagnosed.

The ECG is from Image 1 of the eMedicine article Multifocal Atrial Tachycardia. Available at: http://www.emedicine.com/med/topic1518.htm.

BACKGROUND

A 75-year-old man presents to his primary care physician with a gradual onset of shortness of breath and a productive cough that has lasted more than 2 days. These were followed by sudden palpitations and dizziness. The patient has a history of emphysema and is receiving oxygen therapy at home. He complains of pleuritic chest pain on his right side that has been sporadic for 30 hours, and he admits to using inhalers more frequently than usual. An ECG is obtained. The patient is told to seek immediate medical attention for digoxin and possible cardioversion. What is the heart rhythm? Should this patient undergo direct-current (DC) cardioversion?

Hint

Note at least 3 morphologically distinct P waves, irregular P-P intervals, and an isoelectric baseline between P waves on the ECG. The patient^s pulse is irregular at a rate of 120 beats per minute. The patient^s blood pressure is 160/90 mm Hg.

Author: Michael Zevitz, MD, and Neeraj Tandon, MD

Finch University of Health Sciences/The Chicago Medical School and Overton Brooks VA Medical Center, Louisiana State University School of Medicine

eMedicine Editor: John Vozenilek, MD

Division of Emergency Medicine, Evanston Northwestern Healthcare

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