Which type of arrhythmia may present with a "saw-tooth" pattern on the ECG?

• A. Atrial fibrillation
• B. Atrial flutter
• C. Ventricular tachycardia
• D. Sinus bradycardia

Answer: (B)

The correct answer describes atrial flutter, which is characterized by a distinctive "saw-tooth" pattern on an electrocardiogram (ECG). This pattern, often referred to as "F-waves" or "flutter waves," is typically seen in the inferior leads (II, III, and aVF) and suggests that the heart's atria are rapidly firing at a rate of about 250 to 350 beats per minute. This rapid firing results in a regular and organized pattern that contrasts with the irregularly chaotic waves noted in atrial fibrillation. In atrial flutter, the electrical conduction travels in a consistent circular pathway within the atria, leading to the characteristic saw-tooth appearance, especially noticeable in lead II. Additionally, atrial flutter can lead to a variety of symptoms, including palpitations and shortness of breath, and requires appropriate management to prevent complications such as thromboembolism.

In contrast, atrial fibrillation presents with an irregularly irregular rhythm with no distinct P waves. Ventricular tachycardia features a wide QRS complex and is not associated with a saw-tooth pattern. Sinus bradycardia involves a slow heart rate associated with a regular rhythm, typically showing a normal