The Normal ECG

Question 1 What does the P wave represent in a normal ECG? • A) Ventricular depolarization • B) Atrial depolarization • C) Ventricular repolarization • D) Atrial repolarization Answer: B) Atrial depolarization Rationale: The P wave reflects the electrical activity associated with atrial depolarization. ________________________________________ Question 2 Which interval on the ECG indicates the time it takes for electrical conduction from the atria to the ventricles? • A) PR interval • B) QRS complex • C) QT interval • D) ST segment Answer: A) PR interval Rationale: The PR interval measures the time from the onset of atrial depolarization to the onset of ventricular depolarization. ________________________________________ Question 3 What is the normal duration of the QRS complex? • A) Less than 0.10 seconds • B) 0.10 to 0.12 seconds • C) 0.12 to 0.20 seconds • D) Greater than 0.20 seconds Answer: A) Less than 0.10 seconds Rationale: A normal QRS complex duration is less than 0.10 seconds, indicating efficient ventricular depolarization. ________________________________________ Question 4 In a normal ECG, what does the T wave represent? • A) Atrial depolarization • B) Ventricular depolarization • C) Ventricular repolarization • D) Atrial repolarization Answer: C) Ventricular repolarization Rationale: The T wave reflects the process of ventricular repolarization. ________________________________________ Question 5 Which of the following heart rates is considered normal for adults? • A) 40-60 bpm • B) 60-100 bpm • C) 100-120 bpm • D) 120-160 bpm Answer: B) 60-100 bpm Rationale: A normal resting heart rate for adults typically ranges from 60 to 100 beats per minute. ________________________________________ Question 6 What is the significance of the ST segment in the ECG? • A) It reflects atrial contraction. • B) It indicates ventricular repolarization. • C) It represents the time between depolarization and repolarization of the ventricles. • D) It shows the heart's electrical axis. Answer: C) It represents the time between depolarization and repolarization of the ventricles. Rationale: The ST segment is crucial in assessing the heart's recovery phase and is often analyzed for abnormalities indicating ischemia. ________________________________________ Question 7 Which lead placement is associated with the inferior view of the heart in a 12-lead ECG? • A) V1-V2 • B) I and aVL • C) II, III, and aVF • D) V3-V6 Answer: C) II, III, and aVF Rationale: Leads II, III, and aVF provide an inferior view of the heart. ________________________________________ Question 8 A nurse is interpreting an ECG and notes that the QRS complex is wide. What could this indicate? • A) Normal conduction • B) Atrial fibrillation • C) Bundle branch block • D) Tachycardia Answer: C) Bundle branch block Rationale: A wide QRS complex often indicates delayed conduction in the ventricles, such as in a bundle branch block. ________________________________________ Question 9 What is the proper nursing action if a patient’s ECG shows a sustained ventricular tachycardia? • A) Document findings and continue monitoring. • B) Initiate cardiopulmonary resuscitation (CPR) immediately. • C) Assess the patient for pulse and prepare for possible defibrillation. • D) Administer oral medications as prescribed. Answer: C) Assess the patient for pulse and prepare for possible defibrillation. Rationale: Sustained ventricular tachycardia can be life-threatening; the nurse must assess the patient and prepare for advanced interventions. ________________________________________ Question 10 The nurse notes that the PR interval is consistently 0.16 seconds. How should the nurse interpret this finding? • A) Normal conduction time • B) Shortened conduction time • C) Prolonged conduction time • D) Indeterminate Answer: A) Normal conduction time Rationale: A PR interval of 0.16 seconds is within the normal range (0.12 to 0.20 seconds). ________________________________________ Question 11 In a normal ECG, which segment should be flat and isoelectric? • A) P wave • B) PR interval • C) ST segment • D) T wave Answer: C) ST segment Rationale: The ST segment should be isoelectric, indicating no net movement of electrical charge during this phase of the cardiac cycle. ________________________________________