EP IBHRE LEARNING COMPANION 2026
CATHETER ABLATION AND MAPPING
SYSTEMS FUNDAMENTALS
◉ which 2 cardiac tissues have a slow phase 0 action potential and
thus a slow conduction velocity
Answer: SA and AV node
◉ what is the response of cardiac tissue paced during relative
refractory period? compared to fully repolarized cells stimulation in
the RRP ___
Answer: require higher mA but create a weaker contraction
◉ which of the following is the hearts normal conduction sequence
to the His bundle
Answer: SA node, RA atrial muscle, LA muscle, AV node
◉ which of the following is normal conduction sequence after an
electrical impulse has traveled through the AVN
Answer: His, bundle branches, purkinje fibers
◉ which is not required to sustain a reentry circuit
, Answer: one pathway is an isthmus between 2 conductive areas
◉ what causes fractionated electrograms
Answer: nonuniform anisotropy (zigzag conduction)
◉ the pause after rapid atrial pacing ceases is termed
Answer: overdrive suppression
◉ most arrhythmias in the EP lab are caused by
Answer: reentry
◉ the "triggered" mechanism may cause an arrythmia. triggered
arrhythmias are often associated with digitalis toxicity or elevated
interventricular Ca++ levels. what mechanism causes triggered
arrhythmias?
Answer: after-depolarization
◉ When an A signal is seen to progress on a CS cath from the prox to
the distal it is termed ______. When the CS leads are stacked on the
recorder screen with prox on top, the signal will normally proceed
_______
Answer: Concentric, diagonally downward right
CATHETER ABLATION AND MAPPING
SYSTEMS FUNDAMENTALS
◉ which 2 cardiac tissues have a slow phase 0 action potential and
thus a slow conduction velocity
Answer: SA and AV node
◉ what is the response of cardiac tissue paced during relative
refractory period? compared to fully repolarized cells stimulation in
the RRP ___
Answer: require higher mA but create a weaker contraction
◉ which of the following is the hearts normal conduction sequence
to the His bundle
Answer: SA node, RA atrial muscle, LA muscle, AV node
◉ which of the following is normal conduction sequence after an
electrical impulse has traveled through the AVN
Answer: His, bundle branches, purkinje fibers
◉ which is not required to sustain a reentry circuit
, Answer: one pathway is an isthmus between 2 conductive areas
◉ what causes fractionated electrograms
Answer: nonuniform anisotropy (zigzag conduction)
◉ the pause after rapid atrial pacing ceases is termed
Answer: overdrive suppression
◉ most arrhythmias in the EP lab are caused by
Answer: reentry
◉ the "triggered" mechanism may cause an arrythmia. triggered
arrhythmias are often associated with digitalis toxicity or elevated
interventricular Ca++ levels. what mechanism causes triggered
arrhythmias?
Answer: after-depolarization
◉ When an A signal is seen to progress on a CS cath from the prox to
the distal it is termed ______. When the CS leads are stacked on the
recorder screen with prox on top, the signal will normally proceed
_______
Answer: Concentric, diagonally downward right
