ECG Study Guide 2026
Everything you need to pass the ECG exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
ECG exam key facts
📋 ECG Exam Format at a Glance
📚 ECG Topics to Study (35)
✍️ Sample ECG Questions & Answers
1. If the limb leads on the right and left arms are reversed, what change is commonly seen?
Right/left arm lead reversal typically inverts lead I and can mimic pathology.
2. The nurse looks at an ECG strip, detects a Q wave, and determines that this waveform is
While small, narrow Q waves can be a normal variant in some leads, the presence of a *significant* or pathological Q wave (wider than 0.04 seconds or deeper than 25% of the R wave amplitude) is a hallmark of myocardial infarction. In a clinical setting, when a nurse 'detects a Q wave,' the primary concern often shifts to assessing if it represents this critical pathology, making its visibility a strong indicator of past cardiac damage.
3. What is the maximum safe leakage current from an ECG machine to the patient?
IEC 60601 limits patient auxiliary current (leakage) to 10 µA for cardiac floating-type connections, since even tiny currents can induce ventricular fibrillation if they reach the heart directly.
4. Peaked, narrow, symmetrical T-waves in multiple leads are a classic ECG sign of:
Tall, peaked, narrow, symmetrical T-waves are an early ECG manifestation of hyperkalemia, reflecting altered ventricular repolarization from elevated extracellular potassium.
5. A patient taking amiodarone is most likely to show which ECG finding?
Amiodarone prolongs ventricular repolarization, resulting in a prolonged QT interval on the ECG.
6. A patient receiving IV procainamide (Class IA) for ventricular arrhythmia may develop which dangerous ECG pattern?
Procainamide can widen the QRS by more than 50% of the baseline width, signaling toxicity and increased risk of proarrhythmia.
🎯 Free ECG Practice Tests
📖 ECG Guides & Articles
What Practice Test Geeks adds beyond an AI chat for ECG
An AI chatbot can quiz you, but it can't reproduce the exam conditions or keep your record. Here you get:
- A timed, full-length ECG mock exam — 120 questions in 120 minutes with a 70% pass mark, modeled on the official exam's question count and time limit, followed by a score report broken down by exam domain.
- A fixed ECG question bank: the same test every attempt, so your score is comparable from one try to the next instead of changing with every regenerated quiz.
- Progress saved on your device: completed tests, scores and missed questions stay in My Progress, so you can retake only what you got wrong.
- A printable ECG cheat sheet you can print or save as a PDF.
- ECG flashcards built from the same question bank.
- Free ECG practice tests with the correct answer shown after each question.
How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy
Sources & references
Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy
- nhanow.com — Passing score, test delivery, eligibility, renewal, score release, time limit · verified Oct 2026
- cci-online.org — Test delivery, fees, exam format, passing score, renewal, score release · verified Oct 2026