CVT Electrophysiology Studies & Catheter Ablation 3

Question 1

What is the primary role of the coronary sinus (CS) catheter during an EP study?

Accepted Answer

To provide electrograms and anatomical landmarks for left-sided mapping and atrial pacing

Answer

To measure right heart filling pressures

Answer

To deliver ablation energy directly to the AV node

Answer

To assess left anterior descending artery flow

Question 2

AVNRT (AV Nodal Reentrant Tachycardia) involves a reentrant circuit using:

Accepted Answer

Fast and slow conduction pathways within or near the AV node

Answer

An extranodal accessory pathway bridging the AV groove

Answer

Macro-reentry around the tricuspid annulus

Answer

Ectopic firing from the pulmonary vein ostia

Question 3

During transseptal puncture for left atrial access, the needle targets which anatomical landmark?

Accepted Answer

Fossa ovalis

Answer

Tricuspid annulus

Answer

Eustachian ridge

Answer

Coronary sinus ostium

Question 4

During ventricular tachycardia (VT) ablation, what does entrainment mapping help the electrophysiologist determine?

Accepted Answer

Whether the pacing site is within or adjacent to the VT reentry circuit

Answer

The location of the sinus node

Answer

The degree of myocardial fibrosis on MRI

Answer

The morphologic origin of the surface QRS complex

Question 5

Which pharmacological agent is most commonly used to unmask accessory pathway conduction or facilitate tachycardia induction during EP testing?

Accepted Answer

Isoproterenol

Answer

Adenosine

Answer

Amiodarone

Answer

Digoxin

Question 6

Typical (common) atrial flutter is a macroreentrant circuit that travels around the tricuspid annulus; the critical slow-conduction zone targeted for ablation is the:

Accepted Answer

Cavotricuspid isthmus (CTI)

Answer

Crista terminalis

Answer

Mitral isthmus

Answer

Bachmann's bundle

Question 7

What does 'concealed entrainment' indicate when found during VT substrate mapping?

Accepted Answer

The paced QRS morphology is identical to VT morphology, indicating the site is within the protected isthmus of the circuit

Answer

The paced QRS morphology differs from VT, confirming an outer loop bystander site

Answer

The VT terminates with pacing, indicating the site is the exit point

Answer

The VT cannot be entrained, indicating the site is outside the circuit entirely