RCES common mistakes
RCES · Understand the traps and how to avoid them.
Reciting the boundaries of the triangle of Koch (tendon of Todaro, tricuspid annulus, coronary sinus ostium) as a memorized list but being unable to say which structures sit inside it or which way a catheter must move to reach the slow pathway or His bundle.
Anatomy is studied as vocabulary lists from review outlines rather than as a spatial map, so questions that require reasoning about a catheter's position or a complication risk (e.g., which structure is at risk during slow pathway modification) collapse even though the names are known.
What to do instead
Practice drawing the right atrium in LAO and RAO from memory: place the His bundle, CS ostium, Todaro tendon, fossa ovalis, and Koch's triangle on the sketch, then predict where a catheter must be advanced or curved for each target. Rehearse the same drawing from the femoral-to-cardiac trajectory.
Reading a wide, slurred intracardiac electrogram or a distorted surface ST segment as a true physiologic signal without first checking what filter settings are in use.
Candidates learn filter ranges as isolated numbers and never connect them to the displayed waveform, so they cannot tell whether broadening, ringing, or baseline drift was produced by the amplifier or by the heart.
What to do instead
Learn the practical consequences, not just the numbers: high-pass filtering removes low-frequency content (distorts ST segments and slow far-field signals), low-pass filtering rounds off sharp local deflections, and 50/60 Hz notch can hide real high-frequency activity. Before interpreting any unusual morphology, state the active filter band out loud and ask whether the appearance is explained by it.
Treating unipolar and bipolar recordings as interchangeable, and misjudging stimulus artifact size, pacing threshold, or far-field content when switching between the two.
The two configurations are memorized as definitions rather than as practical trade-offs, so the larger stimulus artifact and broader far-field pickup of a unipolar distal recording gets misread as a local signal, or a bipolar signal is expected to show the same amplitude as a unipolar one.
What to do instead
Build a side-by-side comparison table (electrode pair, signal sharpness, far-field pickup, stimulus artifact, noise susceptibility) and apply it when assessing local activation timing, capture, and threshold testing; confirm questionable signals by switching configuration and re-measuring.
Measuring AH, HV, and PA intervals from the wrong fiducial point, typically from the surface P-wave onset or from the peak rather than the onset of the sharp intracardiac deflection.
Surface ECG habits carry over: candidates anchor to the P wave they can see on the monitor and to visually obvious peaks, which systematically lengthens or shortens the reported interval and can flip the interpretation of conduction disease.
What to do instead
Adopt and state a single rule before measuring (onset of the earliest sharp deflection on the intracardiac channel to onset of the next sharp deflection), verify it on a second channel, and sanity-check the result against the expected normal range and against a second beat at the same cycle length.
Naming an SVT mechanism from a single observation (for example, calling AVNRT because the VA interval is short) instead of working through a deliberate sequence of pacing and extrastimulus maneuvers.
Textbook association tables are easier to memorize than the logic of each maneuver, so candidates pattern-match the most familiar feature and stop, and then choose the answer that fits that feature rather than the mechanism supported by the full data set.
What to do instead
Practice a fixed diagnostic algorithm for every narrow-complex tachycardia: establish A-V relationship and septal VA timing, then apply His-refractory PVCs, para-Hisian pacing, PVC during His refractoriness, and differential ventricular pacing, noting what each result rules in and out before committing to a mechanism.
Reporting an effective refractory period or a conduction limit that was actually produced by loss of capture, catheter dislodgment, or too-coarse a decrement in the coupling interval.
The endpoint is treated as 'the number where the response disappeared' without distinguishing failure to capture from true tissue refractoriness, and large decrements or a drifting catheter position are not accounted for.
What to do instead
Before reporting any refractory value, confirm capture at each coupling interval, use a standardized drive train and 10 ms decrements, check catheter stability and threshold at the end of the run, and document the drive cycle length and the stimulus strength used.
Continuing radiofrequency delivery after an impedance rise, a sudden power drop, a temperature spike, or a change in electrogram amplitude, rather than stopping to reassess catheter contact and coagulum.
Attention is fixed on the arrhythmia endpoint (elimination of the potential or termination of tachycardia), and the generator readouts are treated as background information rather than as safety endpoints.
What to do instead
Predefine explicit stop criteria before the first lesion (for example, an abrupt impedance rise, a loss of power despite a set output, or a temperature above the expected target range), verbally announce generator values at intervals during the lesion, and rehearse the stop-check-clear-reposition sequence.
Accepting device marker-channel annotations as the truth about a stored episode instead of reconstructing the actual sensed and paced events from the electrograms and their timing.
The marker channel is visually simple and reads like a summary, so candidates skip the EGM and therefore misclassify oversensing, undersensing, far-field atrial sensing, or appropriate versus inappropriate therapy.
What to do instead
Interpret every stored episode in a fixed order: identify each chamber's EGM, measure the true event intervals, then compare them to what the markers claim; classify the episode as appropriate or inappropriate only after that reconstruction.
Redosing a sedative or analgesic during a case on a fixed schedule or in response to a single movement, without reassessing respiratory rate, oxygenation, blood pressure, and time since the last dose.
Procedural urgency and the desire to keep the patient comfortable drive bolus stacking, and the cumulative and delayed effects of agents whose peak effect lags the dose are underestimated.
What to do instead
Before every supplemental dose, state the last dose time, cumulative dose, current sedation level, respiratory rate, oxygen saturation, and blood pressure; titrate in small increments to a defined sedation endpoint and know each agent's onset, duration, and hemodynamic profile.
Treating radiation and sterile-field practices and scope-of-practice questions as common sense and answering from what 'seems reasonable' rather than from stated standards.
These topics feel administrative compared with electrophysiology content, so they receive little study time, and candidates answer by intuition on questions about fluoroscopy time and collimation, shielding, sterile technique in the EP lab, or which tasks fall within the technologist's role.
What to do instead
Review the lab's radiation safety and infection control policies and the professional scope-of-practice statement as examinable content: know the ALARA principles that apply in the EP lab, the correct use of shielding and collimation, and which actions require physician direction, then practice applying them to scenario-style questions.