Certified EkG technician (CET) Practice Exam

What rhythm pattern should a technician expect after a pacing spike in a patient with a ventricular pacemaker?

1. Normal sinus rhythm

2. Wide QRS interval

3. Irregular heart rhythm

4. Electromechanical dissociation

The correct answer is: Wide QRS interval

After a pacing spike in a patient with a ventricular pacemaker, the most expected rhythm pattern is a wide QRS interval. This is because ventricular pacing involves the direct stimulation of the ventricles, and when they are paced, the electrical impulse bypasses the usual conduction pathways of the heart, namely the atrioventricular (AV) node and the bundle branches. As a result, the ventricles contract in a manner that is not coordinated with the atrial contraction, leading to a depolarization that is wider than normal. A wide QRS complex indicates that the electrical impulse is taking longer than usual to travel through the ventricles, which substantiates the presence of a pacemaker on the ventricular side. This is a characteristic finding in patients receiving ventricular pacing, as the conduction is not occurring through the normal physiological pathways. Understanding this phenomenon is crucial for the technician, as it helps to differentiate normal conduction patterns from those influenced by pacing devices, allowing for clearer and more accurate monitoring and interpretation of the patient’s cardiac rhythm.