Cardiac Rhythm Management Devices Flashcards
7 cards from real CVT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Cardiac Rhythm Management Devices flashcards as text
Which parameter directly controls how long an ICD withholds therapy after a tachycardia detection to allow spontaneous termination?
Answer: Sustained rate duration (SRD)
Sustained rate duration is a programmable delay after initial detection that allows a tachycardia to self-terminate before therapy is delivered, reducing unnecessary shocks.
In cardiac resynchronization therapy, the left ventricular lead is typically positioned via which approach?
Answer: Coronary sinus and a lateral/posterolateral branch vein
The LV lead is advanced through the coronary sinus into a lateral or posterolateral cardiac vein to pace the lateral wall of the left ventricle.
When programming rate-responsive pacing (DDDR mode), the sensor controls which pacing parameter?
Answer: The lower rate limit, allowing it to increase with activity
Rate-responsive pacing raises the lower (base) pacing rate in response to a sensor signal (e.g., accelerometer or minute ventilation), mimicking physiologic heart rate increases with exercise.
Wenckebach upper rate behavior in a DDD pacemaker occurs when:
Answer: The intrinsic atrial rate exceeds the programmed upper rate limit
When the intrinsic atrial rate exceeds the upper tracking rate, the pacemaker progressively lengthens the AV interval until a P-wave falls in the PVARP and is not tracked, creating a Wenckebach pattern.
A pacemaker-dependent patient is scheduled for monopolar electrosurgery. What precaution is most critical?
Answer: Switch the device to an asynchronous mode and have external defibrillation available
Programming to asynchronous mode prevents electrocautery from inhibiting pacing output, and having external backup defibrillation available addresses the risk of device-induced arrhythmias.
Which complication is uniquely associated with the left ventricular lead of a CRT device compared to a standard RV lead?
Answer: Phrenic nerve (diaphragmatic) stimulation
The lateral cardiac veins used for LV lead placement are in close proximity to the phrenic nerve, making diaphragmatic stimulation a common and unique complication of CRT.
What is the primary advantage of His bundle pacing (HBP) over conventional right ventricular apical pacing?
Answer: Physiologic ventricular activation using the native conduction system
His bundle pacing activates the ventricles through the native His-Purkinje system, producing narrow QRS complexes and preserving normal ventricular synchrony, unlike the dyssynchrony from RV apical pacing.