PCCN practice exam questions with correct answers

Pt on Vtach, HR 135, RR 32, BP 90/48, conscious but c/o dizziness, recent K+ lvl is 3.4. What action would you do first? a. emergent defib b. amio 300mg IVP c. emergent cardioversion d. hang 10 mEq KCL/50mL D5W CORRECT ANSWER C The nurse notes the following when analyzing a patient's telemetry strip: HR, 65/min and regular; PR interval, 0.22 seconds; QRS complex, 0.10 seconds; QTc, 0.52 seconds. Which of the following dysrhythmias is the patient at risk for? A. Atrial fibrillation because the PR interval is wide B. Sinus arrhythmia because the QRS complex is narrow C. Torsades de pointes because the QTc is wide D. Third-degree heart block because the PR interval is narrow CORRECT ANSWER C. QT measurements reflect the duration of ventricular repolarization. Lengthening of QT interval is associated with arrhythmias, adverse cardiac events, and increased mortality because a longer QT duration places the vulnerable ventricular repolarization phase close to the next depolarization, increasing the likelihood of R-on-T. The most common arrhythmia that occurs with prolonged QTc is torsades de pointes. Atrial fibrillation, sinus bradycardia, and third-degree heart block are not typically associated with prolonged ventricular repolarization (QTc >0.50 seconds).