ECG Review: Flutter or the Patient?
By Ken Grauer, MD, Professor Emeritus in Family Medicine, College of Medicine, University of Florida. Dr. Grauer is the sole proprietor of KG-EKG Press, and publisher of an ECG pocket brain book.
Scenario: The lead II rhythm strip shown above was observed on telemetry. Is the patient in atrial flutter?
Interpretation: At first glance, one might be tempted to say atrial flutter was present. However, more careful inspection suggests that the baseline deflections do not represent atrial activity at all. In adults, atrial activity with atrial flutter is almost always regular at a rate of between 250-to-350/minute. Typically it manifests a "sawtooth" pattern in lead II. The deflections in question for this example are more geometric in configuration (i.e., vertical) they are irregular and they far exceed the expected rate range for atrial flutter in an adult because they occur at a rate of between 400-to-500/minute. A look at the patient confirmed that these small amplitude vertical deflections were the result of tremor artifact.
It is difficult to determine the true rhythm in the figure. The rate (95-to-100/minute), apparently normal QRS duration, and near regularity of the rhythm suggest a sinus etiology. That said, one could not rule out the possibility of either accelerated junctional rhythm (since no definite P waves are seen) or atrial fibrillation (since there is a slight irregularity to the rhythm). If there was a need to know clinically, one could either attempt to repeat the rhythm strip or obtain a 12-lead ECG in the hope that other leads might be less distorted by artifact.
Artifact is common. Patients have been medicated, and even cardioverted or defibrillated when artifact has not been recognized or has been misinterpreted. Familiarity with the common types of artifact encountered and attention to a few basic points usually makes recognition easy. Suspect artifact whenever physical or electrocardiographic findings do not "fit" with the arrhythmia diagnosis being contemplated. Thus, a chaotic pattern without any organized activity cannot be ventricular fibrillation if the patient remains awake and alert. Similarly, deflections occurring at a rate of 400-to-500 times/minute (as in the figure) are far too rapid to be atrial flutter especially in view of the morphology, irregularity, and clinical history (of tremor) in this case.
A final point worthy of mention relates to Parkinson's tremor. The four-to-six cycle per second speed of this tremor may mimic atrial flutter. Key distinguishing features of Parkinsonian tremor are: 1) irregularity of tremor deflections, 2) more geometric appearance (up-and-down) than "sawtooth," and 3) a look at the patient shows tremor.
Scenario: The lead II rhythm strip shown above was observed on telemetry. Is the patient in atrial flutter?You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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