ECG Notes & MCQs for Nursing Competitive Exams 2025
Introduction
Welcome, nursing students! The Electrocardiogram (ECG) is a critical skill for clinical practice and a high-yield topic in exams like AIIMS NORCET, NCLEX-RN, RRB Staff Nurse, ESIC, JIPMER, DSSSB, and PGIMER. This comprehensive guide offers detailed notes, 55+ MCQs from 2020–2025, clinical scenarios, mnemonics, and exam strategies in simple English to help you excel.
This post is designed for nursing students aiming to master ECG interpretation for 2025 exams.
What is an ECG?
An ECG records the heart's electrical activity using electrodes placed on the skin. It’s a non-invasive diagnostic tool used to identify:
- Arrhythmias [AIIMS NORCET 2025].
- Myocardial infarction (MI) [NHA EKG 2025].
- Electrolyte imbalances [DSSSB 2024].
- Conduction defects [NCLEX-RN 2025].
Key Features: Quick, painless, widely used in emergency rooms, ICUs, and outpatient settings.
ECG Machine and Lead System
The ECG machine uses 12 leads to capture heart activity from different angles [NHA EKG 2025].
Types of Leads
- Limb Leads (6): I, II, III (bipolar); aVR, aVL, aVF (augmented).
- Chest Leads (6): V1–V6.
- Total: 12 leads [AIIMS NORCET 2025].
Lead Placement
- Limb Leads: Placed on arms and legs.
- Chest Leads:
- V1: 4th intercostal space, right sternal border.
- V2: 4th intercostal space, left sternal border.
- V3: Midway between V2 and V4.
- V4: 5th intercostal space, midclavicular line.
- V5: Anterior axillary line, same level as V4.
- V6: Midaxillary line, same level as V4 [NHA EKG 2025].
ECG Settings
- Paper Speed: 25 mm/sec [ESIC 2022].
- Calibration: 1 mV = 10 mm.
- 1 Small Square: 0.04 sec (40 ms), 0.1 mV.
- 1 Large Square: 0.20 sec (200 ms), 0.5 mV [AIIMS NORCET 2025].
Mnemonic: “Right Arm, Left Arm, Left Leg for limb leads; V1–V6 across the chest like a rainbow.”
ECG Waves and Intervals
| Component | Represents | Normal Value |
|---|---|---|
| P Wave | Atrial depolarization | <0 .12="" 2025="" mm="" norcet="" sec="" td=""> |
| QRS Complex | Ventricular depolarization | <0 .12="" 2025="" ekg="" sec="" td=""> |
| T Wave | Ventricular repolarization | <5 2024="" leads="" limb="" mm="" td=""> |
| PR Interval | Atrial to ventricular conduction | 0.12–0.20 sec [NCLEX-RN 2025] |
| QT Interval | Total ventricular activity | 0.36–0.44 sec [PGIMER 2024] |
Key Points:
- Absent P wave in atrial fibrillation [RRB 2024].
- Wide QRS (>0.12 sec) indicates bundle branch block [JIPMER 2023].
- Prolonged PR interval (>0.20 sec) = first-degree heart block [NCLEX-RN 2025].
Common Arrhythmias
| Arrhythmia | ECG Features | Clinical Notes |
|---|---|---|
| Sinus Rhythm | HR 60–100 bpm, regular P-QRS-T | Normal [AIIMS NORCET 2020] |
| Sinus Bradycardia | HR <60 bpm="" regular="" td=""> | Athletes, hypothermia [NCLEX-RN 2025] |
| Sinus Tachycardia | HR >100 bpm, regular | Fever, stress [ESIC 2024] |
| Atrial Fibrillation | No P waves, irregular QRS | Stroke risk [RRB 2024] |
| Atrial Flutter | Sawtooth P waves (F waves) | 2:1 or 3:1 block [AIIMS 2024] |
| Ventricular Fibrillation | Chaotic, no clear waves | Defibrillation [NHA EKG 2025] |
| First-Degree Heart Block | PR >0.20 sec | Benign [NCLEX-RN 2025] |
Mnemonic: “Atrial Flutter = Sawtooth; Atrial Fibrillation = Jiggly baseline.”
ECG in Myocardial Infarction (MI)
Types of MI
- STEMI: ST elevation, Q waves [NHA EKG 2025].
- NSTEMI: ST depression, T wave inversion [NHA EKG 2025].
MI Locations and Leads
| MI Location | Leads Affected | Artery Involved |
|---|---|---|
| Inferior Wall | II, III, aVF | Right coronary [UP NHM CHO 2024] |
| Anterior Wall | V1–V4 | Left anterior descending [JIPMER 2024] |
| Lateral Wall | I, aVL, V5–V6 | Circumflex [RRB 2023] |
| Posterior Wall | V7–V9, reciprocal in V1–V2 | RCA or circumflex [NCLEX-RN 2025] |
Nursing Interventions
- Oxygen (2-4 L/min) [NCLEX-RN 2025].
- Monitor vitals every 5-15 minutes.
- Aspirin (325 mg chewable) [NCLEX-RN 2025].
- Prepare for PCI or thrombolytics.
Mnemonic: “II, III, MI = Inferior MI; V1–V4 = Anterior MI.”
ECG in Electrolyte Imbalances
| Electrolyte Issue | ECG Changes | Nursing Actions |
|---|---|---|
| Hyperkalemia | Tall, peaked T waves, wide QRS | Calcium gluconate [DSSSB 2024] |
| Hypokalemia | U waves, flat T waves | K+ supplements [PGIMER 2024] |
| Hypercalcemia | Short QT interval | Hydrate patient [DSSSB 2023] |
| Hypocalcemia | Prolonged QT interval | Calcium [PGIMER 2024] |
Tip: Always check potassium levels in patients with tall T waves to rule out hyperkalemia [DSSSB 2024].
High-Yield Exam Points
- 12 leads in standard ECG [AIIMS NORCET 2025].
- PR >0.20 sec: First-degree heart block [NCLEX-RN 2025].
- ST elevation: Acute MI [NHA EKG 2025].
- Tall T waves: Hyperkalemia [DSSSB 2024].
- U waves: Hypokalemia [PGIMER 2024].
Latest ECG MCQs (2020–2025)
Practice with these 55+ MCQs from 2020–2025, covering key exams.
| Question | Answer | Exam (Year) |
|---|---|---|
| What does P wave show? | Atrial depolarization | AIIMS NORCET (2025) |
| ECG sign for reduced heart blood flow? | ST depression, T wave inversion | NHA EKG (2025) |
| ST depression in multiple leads suggests what? | Myocardial ischemia | NHA EKG (2025) |
| Drug for slow heart rate (50/min) with chest pain? | Atropine | NCLEX-RN (2025) |
| Leads for septal wall activity? | V1 and V2 | NHA EKG (2025) |
| ECG change in pericarditis? | Widespread ST elevation | NHA EKG (2025) |
| Wave absent in atrial fibrillation? | P wave | RRB Staff Nurse (2024) |
| Rhythm with sawtooth pattern? | Atrial flutter | AIIMS Nursing Officer (2024) |
| Electrolyte causing tall T waves? | Hyperkalemia | DSSSB Nurse (2024) |
| Electrolyte causing long QT interval? | Hypocalcemia | PGIMER Staff Nurse (2024) |
| Best lead for arrhythmias? | Lead II | ESIC Staff Nurse (2024) |
| ST elevation in V2–V4 indicates MI where? | Anterior wall | JIPMER Nurse (2024) |
| Leads for inferior wall MI? | II, III, aVF | UP NHM CHO (2024) |
| Common rhythm after heart attack? | Ventricular premature beats | ESIC Staff Nurse (2024) |
| Normal heart axis on ECG? | -30° to +90° | JIPMER Nurse (2024) |
| ECG change in high potassium? | Tall T waves | AIIMS Delhi (2024) |
| Delta waves indicate what condition? | Wolff-Parkinson-White syndrome | ESIC Staff Nurse (2025) |
| ECG sign for acute pericardial inflammation? | Diffuse ST elevation | RRB Staff Nurse (2023) |
| Irregular QRS, no P waves suggests what? | Atrial fibrillation | AIIMS Nurse (2023) |
| Cause of short QT interval? | Hypercalcemia | DSSSB Nurse (2023) |
| Lead for right ventricular activity? | V1 | PGIMER Staff Nurse (2023) |
| Bundle branch block ECG finding? | QRS >0.12 seconds | JIPMER Nurse (2023) |
| Regular P waves, missing QRS suggests what? | Second-degree heart block | ESIC Staff Nurse (2023) |
| Low magnesium ECG change? | Prolonged QT interval | AIIMS NORCET (2023) |
| Leads for lateral wall MI? | I, aVL, V5–V6 | RRB Staff Nurse (2023) |
| Digitalis overdose ECG sign? | AV block, arrhythmias | DSSSB Nurse (2023) |
| Regular P waves, variable PR interval? | Mobitz I (Wenckebach) | PGIMER Staff Nurse (2023) |
| Normal PR interval range? | 0.12–0.20 seconds | AIIMS NORCET (2022) |
| Hypokalemia ECG change? | U waves, flat T waves | RRB Staff Nurse (2022) |
| Standard ECG paper speed? | 25 mm/sec | ESIC Staff Nurse (2022) |
| Complete P-QRS dissociation suggests? | Third-degree heart block | JIPMER Nurse (2022) |
| Acute MI ECG change? | ST elevation | NCLEX-RN (2022) |
| Leads for anterior wall MI? | V1–V4 | AIIMS Nurse (2021) |
| Normal QRS duration? | <0 .12="" seconds="" td=""> | DSSSB Nurse (2021) |
| Drug for ventricular tachycardia with pulse? | Amiodarone | NCLEX-RN (2021) |
| Wolff-Parkinson-White syndrome ECG sign? | Delta waves | ESIC Staff Nurse (2021) |
| Sawtooth baseline rhythm? | Atrial flutter | PGIMER Staff Nurse (2020) |
| Normal heart rate for sinus rhythm? | 60–100 bpm | AIIMS NORCET (2020) |
| Hypothermia ECG finding? | Osborne (J) waves | RRB Staff Nurse (2020) |
| Hyperkalemia ECG change? | Tall T waves | DSSSB (2020) |
| Best lead for inferior wall MI? | II, III, aVF | AIIMS NORCET (2020) |
| Normal QT interval range? | 0.36–0.44 sec | PGIMER (2020) |
Clinical Scenarios with Nursing Interventions
- Chest Pain with ST Elevation
- ECG: ST elevation in II, III, aVF.
- Diagnosis: Inferior wall MI [UP NHM CHO 2024].
- Nursing Actions: Oxygen (2–4 L/min), aspirin (325 mg) [NCLEX-RN 2025], prepare for PCI.
- Kidney Patient with Tall T Waves
- ECG: Tall, peaked T waves, wide QRS.
- Diagnosis: Hyperkalemia [DSSSB 2024].
- Nursing Actions: Calcium gluconate, monitor vitals [DSSSB 2024].
- Palpitations with Irregular Rhythm
- ECG: No P waves, irregular QRS.
- Diagnosis: Atrial fibrillation [RRB 2024].
- Nursing Actions: Anticoagulants (e.g., heparin), assess pulse deficit [RRB 2024].
- Sudden Collapse
- ECG: Chaotic baseline, no waves.
- Diagnosis: Ventricular fibrillation [NHA EKG 2025].
- Nursing Actions: Start CPR, defibrillator (200 J) [NHA EKG 2025].
- Shortness of Breath with Wide QRS
- ECG: QRS >0.12 sec, regular rhythm.
- Diagnosis: Right bundle branch block [JIPMER 2023].
- Nursing Actions: Monitor for syncope, notify physician [JIPMER 2023].
- Fatigue with Prolonged PR
- ECG: PR interval >0.20 sec.
- Diagnosis: First-degree heart block [NCLEX-RN 2025].
- Nursing Actions: Observe for progression, document findings [NCLEX-RN 2025].
Mnemonics for Quick Recall
- “P before QRS, heart’s at ease”: Sinus rhythm [ESIC 2024].
- “II, III, MI”: Inferior MI in II, III, aVF [UP NHM CHO 2024].
- “High K, High T”: Hyperkalemia with tall T waves [DSSSB 2024].
- “ST up, MI; ST down, ischemia”: STEMI vs. NSTEMI [NHA EKG 2025].
- “V1–V4, anterior core”: Anterior MI in V1–V4 [JIPMER 2024].
- “No P, AF, QRS jiggly”: Atrial fibrillation [RRB 2024].
Mnemonic Tip: Use these to recall during high-pressure exams!
Quick Reference: Normal ECG Values
| Parameter | Normal Value |
|---|---|
| PR Interval | 0.12–0.20 sec [AIIMS NORCET 2022] |
| QRS Duration | <0 .12="" 2021="" sec="" td=""> |
| QT Interval | 0.36–0.44 sec [PGIMER 2024] |
| P Wave Amplitude | <2 .5="" 2025="" mm="" norcet="" td=""> |
| Heart Rate | 60–100 bpm [AIIMS NORCET 2020] |
Revision Checklist for Exam Day
- Memorize normal ECG values (PR, QRS, QT intervals).
- Identify MI locations by leads (e.g., II, III, aVF = inferior).
- Practice arrhythmias: Sinus, atrial, ventricular.
- Review electrolyte changes (e.g., tall T = hyperkalemia).
- Know nursing interventions for MI, VF, AF.
- Use mnemonics for quick recall.
Pro Tip: Review this checklist 24 hours before your exam for a quick refresh!
Exam Strategies
- Learn basics: Lead placement, normal waves, calibration.
- Practice 10–15 ECG strips daily for pattern recognition.
- Use mnemonics to save time in MCQs.
- Check ECG calibration: 10 mm = 1 mV [NHA EKG 2025].
- Prioritize high-yield topics: Arrhythmias, MI, electrolytes.
Common Mistakes to Avoid
- Ignoring calibration: Always verify 10 mm = 1 mV [NHA EKG 2025].
- Mixing ST changes: ST elevation = MI; ST depression = ischemia [NHA EKG 2025].
- Wrong lead identification: Memorize MI-specific leads [JIPMER 2024].
FAQs for Quick Practice
- How many leads in a standard ECG? 12 [AIIMS NORCET 2025].
- Normal PR interval? 0.12–0.20 seconds [AIIMS NORCET 2022].
- Electrolyte for tall T waves? Hyperkalemia [DSSSB 2024].
- Rhythm with sawtooth waves? Atrial flutter [AIIMS 2024].
Study Resources
- Books:
- ECG Interpretation Made Easy: Beginner-friendly.
- Rapid Interpretation of EKGs by Dale Dubin: Visual learning.
- Websites:
- Logyanlo.in: Free MCQs and notes.
- ECG Wave-Maven: Practice strips.
- Apps:
- ECG Guide by QxMD: Quick references.
- Instant ECG: Interactive quizzes.
Tips for Nursing Students
- Create flashcards for normal values and ECG changes.
- Join study groups to discuss ECG strips.
- Stay updated with 2025 exam patterns via official websites.
- Practice daily with online quizzes at www.logyanlo.in.
Conclusion
The ECG is a high-scoring topic for nursing competitive exams. Use these detailed notes, 55+ MCQs, and strategies to ace your 2025 exams. Visit www.logyanlo.in for more resources and practice questions!
Stay Motivated: Consistent practice with ECGs will make you exam-ready!
0 Comments