CET Cheat Sheet 2026

The 30 highest-yield CET facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. A patient on phenytoin (an antiseizure drug with Class IB properties) overdoses. Which ECG finding is most expected? → PR prolongation and widened QRS
2. The sensitivity (gain) setting of 10 mm/mV means: → 1 mV of cardiac signal produces a 10 mm deflection on the ECG paper
3. Which lead is MOST useful for identifying P waves and evaluating atrial activity in pediatric patients? → Lead II
4. What is a key principle of holter monitoring & ambulatory ecg in Certified Electrocardiogram Technician practice? → Applying structured methodologies based on evidence and best practices
5. Which ECG interval measures the combined duration of ventricular depolarization and repolarization? → QT interval from QRS onset to the end of the T wave
6. How often should ECG electrodes be replaced? → After each use
7. Which PPE consideration applies to ECG technicians under standard precautions? → Wear gloves when contact with body fluids, open wounds, or non-intact skin is possible
8. On a rhythm strip, you observe a P wave followed by a progressively lengthening PR interval until a QRS is dropped, then the cycle repeats. What is this rhythm? → Mobitz Type I (Wenckebach) block
9. Sotalol combines beta-blocking and Class III antiarrhythmic properties. Which ECG change is most expected? → Prolonged QT interval
10. When troubleshooting AC interference on an ECG, which action should be performed LAST? → Engage the ECG machine's built-in 60 Hz notch filter as a permanent solution
11. If LA and RA leads are accidentally reversed, which lead combination will appear MOST abnormal compared to the others? → Lead I and aVR
12. During telemetry monitoring, a patient shows 'sawtooth' flutter waves at approximately 300 bpm with a 4:1 AV conduction ratio. The ventricular rate would be: → 75 bpm
13. Which term describes the heart's ability to generate its own electrical impulses without external stimulation? → Automaticity
14. What is a key principle of ecg artifact troubleshooting in Certified Electrocardiogram Technician practice? → Applying structured methodologies based on evidence and best practices
15. During an ECG, a patient on quinidine shows a markedly prolonged QT and polymorphic ventricular tachycardia. This is best described as: → Quinidine syncope / Torsades de Pointes
16. A patient taking beta-blockers before a stress test will most likely exhibit: → Attenuated heart rate and blood pressure response to exercise
17. Which skin preparation step has the greatest impact on reducing electrode impedance and minimizing artifact? → Clipping or shaving excess hair at electrode sites
18. Which patient position is standard when recording a resting 12-lead ECG? → Supine with arms at sides
19. A posterior ECG (leads V7–V9) is indicated primarily to evaluate: → Posterior wall myocardial infarction
20. In Mobitz II (second-degree AV block), the ECG shows: → Constant PR interval with occasional non-conducted P waves
21. A patient returns a Holter recorder with only 18 hours of data on a prescribed 24-hour study. The BEST next step is to: → Note the incomplete recording and schedule a repeat study if clinically indicated
22. What is the relationship between stress testing procedures and overall Certified Electrocardiogram Technician professional competency? → It is an essential component that strengthens the overall competency framework
23. ST elevation in leads V1–V4 is most consistent with which type of STEMI? → Anterior STEMI
24. Which electrolyte condition is associated with a SHORT QT interval and increased risk of ventricular fibrillation? → Hypercalcemia
25. Sagging ST depression with a prominent U wave is most characteristic of: → Hypokalemia
26. What ECG finding best differentiates left ventricular hypertrophy (LVH) from anterior STEMI? → LVH shows ST elevation in V1–V3 with deep S waves and large R waves elsewhere
27. What is a common sign of myocardial infarction on an ECG? → ST-segment elevation
28. What is the primary reason limb lead cables should not be draped over the patient's body during recording? → Cable movement generates motion artifact via triboelectric effect
29. Which lead is placed at the midaxillary line, level with V4? → V6
30. A neonate's ECG shows a QTc of 500 ms. The most appropriate next step is: → Notify the ordering provider immediately