CVT Cardiac Rhythm Management Devices 2

Question 1

Which pacemaker parameter defines the minimum interval between a sensed or paced event and the next pacing output?

Accepted Answer

Refractory period

Answer

The refractory period prevents the pacemaker from responding to signals (such as T-waves) immediately after a paced or sensed event.

Question 2

In a dual-chamber pacemaker, what occurs during crosstalk inhibition?

Accepted Answer

The ventricular lead senses atrial pacing output and inhibits ventricular pacing

Answer

Crosstalk occurs when the ventricular sensing channel detects the atrial pacing stimulus, potentially inhibiting ventricular output and causing dangerous pauses.

Question 3

Which ICD therapy is delivered first in a standard tiered-therapy protocol for ventricular fibrillation?

Accepted Answer

High-energy defibrillation shock

Answer

Ventricular fibrillation is not amenable to ATP or synchronized cardioversion, so devices deliver high-energy unsynchronized defibrillation as first-line therapy.

Question 4

A patient's ICD interrogation shows 'T-wave oversensing.' What is the most likely consequence?

Accepted Answer

Inappropriate shock delivery

Answer

T-wave oversensing causes the device to double-count cardiac events, potentially satisfying tachycardia detection criteria and delivering inappropriate therapy.

Question 5

What does the term 'cardiac resynchronization therapy (CRT)' specifically aim to correct?

Accepted Answer

Interventricular and intraventricular mechanical dyssynchrony

Answer

CRT uses biventricular pacing to resynchronize the contraction of the left and right ventricles, improving cardiac output in patients with heart failure and conduction delay.

(CVT) Cardiovascular Technologist Certification Practice Test

(CVT) Cardiovascular Technologist Certification Practice Test

CVT Cardiac Rhythm Management Devices 2