Chapter 35: Dysrhythmias Lewis: Medical-Surgical Nursing, 10th Edition

1. To determine whether there is a delay in impulse conduction through the ventricles, the nurse will measure the duration of the patient’s a. P wave. c. PR interval. b. Q wave. d. QRS complex. ANS: D The QRS complex represents ventricular depolarization. The P wave represents the depolarization of the atria. The PR interval represents depolarization of the atria, atrioventricular node, bundle of His, bundle branches, and the Purkinje fibers. The Q wave is the first negative deflection following the P wave and should be narrow and short. DIF: Cognitive Level: Understand (comprehension) REF: 759 TOP: Nursing Process: Assessment MSC: NCLEX: Physiological Integrity 2. The nurse needs to quickly estimate the heart rate for a patient with a regular heart rhythm. Which method will be best to use? a. Count the number of large squares in the R-R interval and divide by 300. b. Print a 1-minute electrocardiogram (ECG) strip and count the number of QRS complexes. c. Use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by 10. d. Calculate the number of small squares between one QRS complex and the next and divide into 1500. ANS: C This is the quickest way to determine the ventricular rate for a patient with a regular rhythm. All the other methods are accurate, but take longer. DIF: Cognitive Level: Analyze (analysis) REF: 759 TOP: Nursing Process: Assessment MSC: NCLEX: Physiological Integrity 3. A patient has a junctional escape rhythm on the monitor. The nurse will expect the patient to have a heart rate of _____ beats/min. a. 15 to 20 c. 40 to 60 b. 20 to 40 d. 60 to 100 ANS: C If the sinoatria