A nurse is caring for a client who is alert and oriented and is receiving continuous ECG monitoring. The cardiac rhythm strip shows a wavy baseline, no distinguishable P waves, and an increased heart rate. The nurse should identify the cardiac rhythm as which of the following?

A. Sinus tachycardia: Incorrect. Sinus tachycardia shows a regular rhythm with identifiable P waves, not a wavy baseline. B. Atrial fibrillation: The wavy baseline with no identifiable P waves and an irregular rhythm is characteristic of atrial fibrillation. C. Second-degree heart block: Incorrect. Second-degree heart block shows a regular rhythm with some dropped QRS complexes, not a wavy baseline. D. Ventricular asystole: Incorrect. Ventricular asystole shows no electrical activity, not a wavy baseline.