Medical Surgical EKG #3

Question

The nurse analyzes the strip below and determines that the interpretation is:

Answers

  1. 2nd Degree Mobitz II
    • Rationale:

      This answer is not correct because in a Mobitz type II heart block (a second degree heart block) there is equal and similar prolongation of the PR interval (much like first degree AV block), but there is a drop of the QRS complex during this heart block. Mobitz type II block reveals some P waves that are not conducted to the ventricles. Third degree AV block or complete heart block is where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles. The ECG will reflect no relation between the P-waves and the QRS complexes. Third degree heart block generally has a wide bizarre QRS with a heart rate of < 40.

  2. Third Degree (Complete) Heart Block
    • Rationale:

      This answer is correct because third degree AV block or complete heart block is where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles. There is an electrical blockage that prevents electrical cardiac impulses in the atria from entering the ventricular conduction system. The ECG will reflect no relation between the P-waves and the QRS complexes. Third degree heart block generally has an extremely low heart rate, such as this one that is 34 bpm. The client with a 34 heart rate will experience weakness, dizziness, confusion, shortness of breath. A pacemaker will have to be placed to make this client perfuse the body properly and prevent a lethal heart arrhythmia.

  3. 1st Degree with BBB
    • Rationale:

      This answer is not correct because in a first degree AV heart block, the PR interval exceeds 0.20 in first degree heart block (normal PR interval is 0.12 – 0.20 seconds). First degree AV block is usually asymptomatic and is a common conduction disturbance. A bundle branch block (BBB) has a widened QRS complex (>0.10 seconds). Although this rhythm has a widened QRS, it does not have a first degree block, but a third degree AV block, where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles.

  4. Atrial flutter
    • Rationale:

      This answer is not correct because atrial flutter presents with a saw-tooth patterned between the QRS complexes. Third degree AV block or complete heart block is where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles. The ECG will reflect no relation between the P-waves and the QRS complexes.

Overview

Third degree AV block or complete heart block is where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles. The ECG will reflect no relation between the P-waves and the QRS complexes.

Explanation

Learning Outcomes

Third degree AV block or complete heart block is where there is no conduction through the AV node, which causes complete dissociation between the atria and ventricles. The ECG will reflect no relation between the P-waves and the QRS complexes. Third degree heart block generally has an extremely low heart rate, such as this one, that is 34 bpm. The client with a 34 heart rate will experience weakness, dizziness, confusion, shortness of breath. A pacemaker will have to be placed to make this client perfuse the body properly and prevent a lethal heart arrhythmia.

Test Taking Tip

Third degree heart block generally has a wide bizarre QRS with a heart rate of < 40. If you look at a rhythm, ruled out other arrhythmias, are still trying to figure out what the rhythm is, and it has a super slow rate of <40 bpm, consider a third degree block. This can be confirmed by looking to see if the P waves and the QRS complexes seem unassociated with each other.

Video Rationale