Cardiac Rhythm Management Devices Flashcards

A patient's ICD log shows multiple 'committed shocks' delivered during sinus tachycardia. Which programming feature, if enabled, could have prevented these shocks?

Answer: Onset criterion (sudden onset)

The sudden onset criterion distinguishes VT (abrupt onset) from sinus tachycardia (gradual onset), withholding therapy when the ventricular rate increases gradually as seen in exercise-induced sinus tachycardia.

Electromagnetic interference (EMI) from a strong external source most commonly causes which pacemaker malfunction?

Answer: Loss of capture due to output inhibition

EMI is most commonly sensed as intrinsic cardiac activity, causing the pacemaker to inhibit its output and potentially producing pauses in pacemaker-dependent patients.

Which finding on an ICD interrogation most reliably confirms appropriate therapy for VF?

Answer: Stored EGM showing disorganized ventricular activity at >300 bpm before the shock

Stored intracardiac electrograms demonstrating disorganized, rapid ventricular activity before therapy confirm that the shock was appropriately triggered by true ventricular fibrillation.

In the NBG (NASPE/BPEG Generic) pacemaker code, what does the fourth position letter 'R' indicate?

Answer: Rate modulation capability

The fourth position of the NBG code indicates rate modulation (R), meaning the device can adjust its pacing rate based on a physiologic sensor signal such as accelerometer or minute ventilation.

A patient with a cardiac resynchronization therapy defibrillator (CRT-D) develops persistent left phrenic nerve stimulation. After exhausting all available LV pacing vectors, the next best option is:

Answer: Surgical epicardial LV lead placement

When all transvenous LV pacing vectors cause phrenic nerve capture, surgical epicardial lead placement on the posterolateral LV wall is the definitive solution to maintain CRT.

What is the significance of the 'elective replacement indicator' (ERI) on a pacemaker or ICD?

Answer: Battery voltage has reached a level indicating 3–6 months of remaining longevity

ERI signals that the device battery has reached the point where generator replacement should be scheduled, typically providing 3–6 months of continued function before the end-of-life (EOL) point.

Remote monitoring of CIEDs (cardiac implantable electronic devices) has been shown to primarily improve patient outcomes by:

Answer: Enabling early detection of device and clinical alerts, reducing time to clinical decision-making

Remote monitoring detects alerts—such as AF, lead integrity issues, or fluid status changes—days to weeks earlier than standard clinic visits, allowing faster clinical intervention.