Pacemakers & Cardiac Devices Flashcards
7 cards from real EKG certification Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pacemakers & Cardiac Devices flashcards as text
What is cardiac resynchronization therapy (CRT) and which patients typically benefit from it?
Answer: Biventricular pacing to synchronize ventricular contraction in patients with heart failure and wide QRS
CRT uses a biventricular pacemaker to simultaneously pace both ventricles, correcting dyssynchrony in heart failure patients with a wide QRS (usually LBBB ≥150 ms) and reduced ejection fraction.
What EKG finding is expected in a patient with a functioning biventricular pacemaker (CRT)?
Answer: Pacemaker spikes followed by a narrow or narrower QRS than the baseline LBBB
Successful CRT results in a narrower paced QRS compared to the patient's native wide LBBB, as simultaneous biventricular activation resynchronizes ventricular contraction.
What is the AOO pacemaker mode?
Answer: Atrium paced, no sensing, asynchronous (fixed-rate) pacing
AOO is asynchronous atrial pacing: the atrium is paced at a fixed rate with no sensing function; this mode ignores any native cardiac activity and paces regardless.
Which measurement on the EKG represents the pacemaker's AV delay (or programmed AV interval) in a dual-chamber device?
Answer: The interval from the atrial pacing spike to the ventricular pacing spike
The AV delay in a dual-chamber pacemaker is measured from the atrial pacing spike to the subsequent ventricular pacing spike, mimicking the natural PR interval.
What is pacemaker-mediated tachycardia (PMT)?
Answer: An endless-loop tachycardia where retrograde P waves trigger repetitive ventricular pacing in a DDD pacemaker
PMT is an endless-loop tachycardia unique to dual-chamber pacemakers where retrograde conduction from a ventricular beat creates a retrograde P wave that is sensed by the atrial channel, triggering repeated ventricular pacing at the upper rate limit.
What is the significance of a pacemaker lead impedance that has dropped suddenly to below 200 ohms?
Answer: Possible lead insulation break or short circuit
A sudden drop in lead impedance below 200 ohms suggests an insulation breach or short circuit in the pacing lead, which can cause inappropriate pacing behavior or failure.
On an EKG strip, a pacemaker spike appears but is not followed by atrial or ventricular depolarization. The patient's intrinsic rate is absent. Which pacemaker malfunction does this describe?
Answer: Failure to capture
Failure to capture is confirmed when pacemaker spikes are present but do not produce myocardial depolarization, and because the intrinsic rate is absent, the patient is pacemaker-dependent and at risk for asystole.