Which statement about atrial fibrillation is most accurate?

Which statement about atrial fibrillation is most accurate?

• A. Regular rhythm with narrow QRS complexes
• B. Embolic events such as cerebrovascular accident and limb ischemia
• C. Sawtooth pattern on ECG
• D. Slow heart rate with AV dissociation

Answer: (B)

Atrial fibrillation causes chaotic atrial activity that leads to an irregularly irregular ventricular response and loss of organized atrial contraction. This results in blood pooling in the left atrium, especially the left atrial appendage, which greatly increases the risk of thrombus formation. If a clot breaks off, it can travel to the brain causing a stroke or to peripheral arteries causing limb ischemia—making embolic events a defining clinical consequence of AF. On ECG, AF usually shows no distinct P waves with an irregularly irregular rhythm and typically a narrow QRS complex unless there’s another conduction problem. The sawtooth pattern is characteristic of atrial flutter, not atrial fibrillation, and a slow heart rate with AV dissociation points away from AF and toward other arrhythmias or heart block.

Atrial fibrillation causes chaotic atrial activity that leads to an irregularly irregular ventricular response and loss of organized atrial contraction. This results in blood pooling in the left atrium, especially the left atrial appendage, which greatly increases the risk of thrombus formation. If a clot breaks off, it can travel to the brain causing a stroke or to peripheral arteries causing limb ischemia—making embolic events a defining clinical consequence of AF.

On ECG, AF usually shows no distinct P waves with an irregularly irregular rhythm and typically a narrow QRS complex unless there’s another conduction problem. The sawtooth pattern is characteristic of atrial flutter, not atrial fibrillation, and a slow heart rate with AV dissociation points away from AF and toward other arrhythmias or heart block.