CCI Pacemaker and Implantable Device Assessment 2

Question 1

Which ECG finding is most consistent with pacemaker failure to capture?

Accepted Answer

Pacing spike not followed by a P wave or QRS complex

Answer

Failure to capture is identified by pacing spikes that do not produce the expected depolarization (P wave or QRS), meaning the stimulus did not excite the myocardium.

Question 2

What is the most common cause of acute pacemaker failure to capture in the early post-implant period?

Accepted Answer

Lead dislodgement

Answer

Lead dislodgement is the most common cause of failure to capture in the early post-implant period, as leads have not yet become secured by fibrosis.

Question 3

T-wave oversensing in a VVI pacemaker most likely results in which pacemaker malfunction?

Accepted Answer

Inappropriate inhibition of pacing output

Answer

When the pacemaker incorrectly senses the T-wave as a QRS complex (oversensing), it is inappropriately inhibited from pacing, which can lead to pauses in a pacemaker-dependent patient.

Question 4

A pacing lead impedance measurement of 150 ohms is most consistent with which condition?

Accepted Answer

Lead insulation breach (short circuit)

Answer

Normal pacing lead impedance is 300–1,000 ohms; impedance below 200 ohms suggests an insulation break causing a short circuit, while >2,000 ohms suggests lead fracture.

Question 5

On chest X-ray, which finding would most suggest right ventricular lead perforation?

Accepted Answer

Lead tip extending beyond the cardiac silhouette

Answer

Lead perforation is suggested when the lead tip appears to extend outside the cardiac shadow on chest X-ray, indicating the lead has pierced the myocardial wall.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Pacemaker and Implantable Device Assessment 2