Which condition may cause the heart to exhibit a "sawtooth" pattern on the ECG?

Which condition may cause the heart to exhibit a "sawtooth" pattern on the ECG?

• A. Atrial fibrillation
• B. Atrial flutter
• C. Ventricular fibrillation
• D. Heart block

Answer: (B)

Atrial flutter is characterized by a distinct "sawtooth" pattern on the ECG, often referred to as "f-waves" or "flutter waves." This pattern is typically best seen in the inferior leads (such as II, III, and aVF) and represents organized, rapid reentrant activity in the atria. The atrial rate in atrial flutter can commonly range from 240 to 340 beats per minute, leading to this characteristic waveform. This organized activity is different from atrial fibrillation, which displays chaotic, irregular waves without a consistent pattern. In conditions like ventricular fibrillation, the ECG shows a disorganized and erratic rhythm with no identifiable waveform. Heart block can cause irregularities in the heart's conduction resulting in pauses, but it does not produce the specific sawtooth pattern seen in atrial flutter. The clear presence of the atrial flutter pattern on the ECG is what makes this choice correct in the context of the question.

Atrial flutter is characterized by a distinct "sawtooth" pattern on the ECG, often referred to as "f-waves" or "flutter waves." This pattern is typically best seen in the inferior leads (such as II, III, and aVF) and represents organized, rapid reentrant activity in the atria. The atrial rate in atrial flutter can commonly range from 240 to 340 beats per minute, leading to this characteristic waveform.

This organized activity is different from atrial fibrillation, which displays chaotic, irregular waves without a consistent pattern. In conditions like ventricular fibrillation, the ECG shows a disorganized and erratic rhythm with no identifiable waveform. Heart block can cause irregularities in the heart's conduction resulting in pauses, but it does not produce the specific sawtooth pattern seen in atrial flutter. The clear presence of the atrial flutter pattern on the ECG is what makes this choice correct in the context of the question.