Electrophysiology Studies & Catheter Ablation 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 Electrophysiology Studies & Catheter Ablation flashcards as text
What is the primary role of the coronary sinus (CS) catheter during an EP study?
Answer: To provide electrograms and anatomical landmarks for left-sided mapping and atrial pacing
The CS catheter lies in the posterior AV groove, recording left atrial and ventricular electrograms and serving as a landmark for left-sided structures.
AVNRT (AV Nodal Reentrant Tachycardia) involves a reentrant circuit using:
Answer: Fast and slow conduction pathways within or near the AV node
AVNRT uses dual AV nodal pathways — a slow pathway (anterograde) and a fast pathway (retrograde) — forming a reentrant circuit near the AV node.
During transseptal puncture for left atrial access, the needle targets which anatomical landmark?
Answer: Fossa ovalis
The fossa ovalis is the thinnest, most compliant portion of the interatrial septum and the safest site for transseptal needle crossing.
During ventricular tachycardia (VT) ablation, what does entrainment mapping help the electrophysiologist determine?
Answer: Whether the pacing site is within or adjacent to the VT reentry circuit
Entrainment mapping compares the post-pacing interval (PPI) to the VT cycle length; a PPI equal to the cycle length indicates the pacing site is within the circuit.
Which pharmacological agent is most commonly used to unmask accessory pathway conduction or facilitate tachycardia induction during EP testing?
Answer: Isoproterenol
Isoproterenol, a beta-adrenergic agonist, increases heart rate and sympathetic tone, enhancing accessory pathway conduction and facilitating SVT induction.
Typical (common) atrial flutter is a macroreentrant circuit that travels around the tricuspid annulus; the critical slow-conduction zone targeted for ablation is the:
Answer: Cavotricuspid isthmus (CTI)
The cavotricuspid isthmus (between the tricuspid annulus and the inferior vena cava) is the narrow slow-conduction zone required for typical flutter; a line of block across it cures the arrhythmia.
What does 'concealed entrainment' indicate when found during VT substrate mapping?
Answer: The paced QRS morphology is identical to VT morphology, indicating the site is within the protected isthmus of the circuit
Concealed entrainment — paced QRS identical to VT with a post-pacing interval equal to the VT cycle length — confirms the pacing site is inside the protected slow-conduction isthmus.