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 Format at a Glance
📚 ECG Topics to Study (45)
✍️ Sample ECG Questions & Answers
1. For an accurate ECG on a female patient, where are the chest electrodes placed relative to breast tissue?
Chest leads should be placed under the breast on the chest wall for accurate signal capture.
2. 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.
3. 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.
4. 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.
5. 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.
6. A flat line on a single lead while others record normally most likely means:
A single flat lead usually indicates a loose, disconnected, or faulty electrode/wire.