5.2 Last-Week Review Map

5.2 Last-Week Review Map

The final week is for consolidation, calm, and targeted repair, not for opening new material. Use the CET blueprint weights to decide where the hours go. The exam scores three domains: Safety, Compliance, and Coordinated Patient Care (~32%), EKG Acquisition (~44%), and EKG Analysis and Interpretation (~24%). Acquisition is the single largest bucket, so if you have to choose, the lead-placement and artifact material earns the most points.

A domain-weighted seven-day map

Notice that Safety is 32% but sits on Day 3: it tends to be the most intuitive domain (patient identification, hand hygiene, do-not-record-on-a-damaged-cable), so a focused single day usually suffices, freeing days for the placement and rhythm material that trips more candidates.

The facts to have cold by exam day

Reduce each domain to a small set of must-know anchors and rehearse them until recall is instant.

Lead placement (Acquisition). Limb leads: RA right arm, LA left arm, LL left leg, RL right leg (ground). Precordial leads: V1 4th intercostal space (ICS) right sternal border; V2 4th ICS left sternal border; V3 midway between V2 and V4; V4 5th ICS left midclavicular line; V5 left anterior axillary line level with V4; V6 left midaxillary line level with V4. A one-ICS error in a chest lead can mimic ischemia or a conduction abnormality.

Normal intervals (Interpretation). Commit these ranges:

• PR interval: 0.12-0.20 s (3-5 small boxes)
• QRS duration: under 0.12 s (less than 3 small boxes)
• QT interval: roughly 0.36-0.44 s, rate-dependent
• One small box = 0.04 s; one large box = 0.20 s at the standard 25 mm/s paper speed
• Standard calibration: 10 mm = 1 mV (a 10 small-box-tall calibration pulse)

Rate methods. The 300 method: 300 divided by the number of large boxes between two R waves (300, 150, 100, 75, 60, 50). The six-second method: count QRS complexes in a 6-second strip and multiply by 10, best for irregular rhythms like atrial fibrillation.

The impulse begins at the sinoatrial (SA) node, the natural pacemaker in the right atrium, spreads across the atria to the atrioventricular (AV) node, where it is briefly delayed (this delay is the PR segment), then travels down the bundle of His, the right and left bundle branches, and finally the Purkinje fibers to depolarize the ventricles. Knowing this path explains the waveform: the P wave is atrial depolarization, the QRS complex is ventricular depolarization, and the T wave is ventricular repolarization.

When a stem describes a delay or block, map it to the structure: a long PR points to AV-node delay, while a wide QRS points to a bundle-branch or ventricular-origin problem.

Final-week discipline

Do short mixed sets, write one rule per miss, and stop opening new study apps or videos. Scattered cramming the night before lowers recall. The day before, review your error-log rules, the interval table, the lead landmarks, and the exam logistics, then rest. Confidence on test day comes from a small, well-rehearsed core, not from a last-minute pile of new facts.

High-yield rhythms and STEMI signs to lock in

The Interpretation domain rewards fast pattern recognition. In the final week, drill this short list until each pattern is instant.

Pair rhythms with the right technician action: document and notify the team for organized abnormal rhythms; recognize ventricular fibrillation, pulseless ventricular tachycardia, and asystole as emergencies that call for activating help and starting the emergency response, never independent interpretation or treatment.

STEMI and ischemia cues

The CET expects you to recognize, not diagnose, the classic injury patterns. Memorize the vocabulary so a stem describing them is obvious:

• ST-segment elevation in two or more contiguous leads suggests an acute ST-elevation myocardial infarction (STEMI) and is the urgent finding to flag immediately.
• ST-segment depression suggests ischemia or injury.
• T-wave inversion can indicate ischemia.
• Pathologic Q waves suggest a prior (older) infarction.

The technician's role is to acquire a clean, correctly-placed tracing and alert the licensed clinician promptly when these signs appear, because a misplaced lead can both create false ST changes and hide real ones. That linkage, accurate placement protecting accurate interpretation, is the through-line connecting the Acquisition and Interpretation domains, and it is exactly the kind of integrated reasoning the CET likes to test.