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ECG Spot Diagnoses (Brugada/WPW)

TL;DR

Images: ECG "Spot" Diagnoses (Brugada/WPW) are high-yield MRCP Part 1 patterns where rapid recognition secures easy marks. Identify Brugada syndrome by coved ST elevation in V1–V3 and WPW by a short PR interval with a delta wave. Distinguishing these from mimics (e.g. STEMI or bundle branch block) is critical for both exam accuracy and clinical safety.


Why this matters

In MRCP Part 1, ECG interpretation is less about exhaustive analysis and more about pattern recognition under time pressure. Brugada syndrome and Wolff–Parkinson–White (WPW) are classic “spot diagnoses” that repeatedly appear due to their distinct ECG signatures and serious clinical implications.

These questions are often designed to test whether you can:

  • Recognise a pattern within seconds

  • Avoid common mimics

  • Recall one or two key management principles

For structured preparation, begin with the MRCP Part 1 overview and reinforce learning with Free MRCP MCQs.


Core sections

1) Brugada syndrome — the essentials

Brugada syndrome is an inherited cardiac channelopathy (commonly involving SCN5A mutations) associated with an increased risk of ventricular arrhythmias and sudden cardiac death.

Clinical clues:

  • Young male patient

  • Syncope or nocturnal agonal respiration

  • Family history of sudden death

Classic ECG finding (Type 1 Brugada):

  • Coved ST elevation ≥2 mm in V1–V3

  • Followed by T-wave inversion

Important:

  • ECG changes may be intermittent

  • Fever and sodium channel blockers can unmask the pattern

2) Brugada — exam-focused recognition

To score quickly:

  • Always inspect V1–V3 first

  • Look specifically for a “coved” morphology

  • Do not confuse with anterior STEMI—Brugada lacks reciprocal ST depression

3) Wolff–Parkinson–White (WPW) — the essentials

WPW syndrome involves an accessory conduction pathway (Bundle of Kent) leading to ventricular pre-excitation.

ECG triad:

  • Short PR interval (<120 ms)

  • Delta wave (slurred upstroke of QRS)

  • Widened QRS complex

Clinical relevance:

  • Atrioventricular re-entrant tachycardia (AVRT)

  • Risk of atrial fibrillation with rapid ventricular conduction

4) WPW — exam-focused recognition

Key strategy:

  • Step 1: Check PR interval → Is it short?

  • Step 2: Look for delta wave

  • Step 3: Confirm widened QRS

In spot questions, the delta wave is the defining clue.

5) High-yield comparison table

Feature

Brugada syndrome

WPW syndrome

Mechanism

Sodium channelopathy

Accessory pathway

Key leads

V1–V3

Global

Hallmark ECG

Coved ST elevation + T inversion

Short PR + delta wave + wide QRS

Risk

Ventricular arrhythmias

AVRT, AF

Exam clue

Syncope, nocturnal events

Palpitations

6) The 5 most tested subtopics

  1. Brugada Type 1 vs Type 2 morphology

  2. Fever-triggered Brugada ECG changes

  3. Identification of subtle delta waves

  4. WPW presenting as irregular broad complex tachycardia (AF)

  5. Contraindicated drugs in WPW (AV nodal blockers)

7) 10 rapid recognition pearls

  1. Brugada = V1–V3 + coved ST elevation

  2. WPW = short PR + delta wave

  3. Brugada mimics STEMI, but no reciprocal changes

  4. WPW mimics bundle branch block, but PR is short

  5. Fever can reveal Brugada pattern

  6. Delta waves may be subtle—look carefully

  7. WPW may present with both narrow and broad tachycardias

  8. Avoid AV nodal blockers in WPW with AF

  9. ICD is definitive therapy for high-risk Brugada

  10. In exams, pattern recognition beats clinical narrative


Practical examples / mini-cases

MCQ: A 28-year-old man presents with palpitations. ECG shows a short PR interval and a slurred upstroke of the QRS complex.

What is the most likely diagnosis?A) Atrial fibrillationB) Wolff–Parkinson–White syndromeC) Bundle branch blockD) Ventricular tachycardia

Answer: B) Wolff–Parkinson–White syndrome

Explanation: The short PR interval and delta wave are diagnostic of WPW. Bundle branch block does not shorten the PR interval. AF would present as an irregular rhythm without consistent delta waves.

Practise similar high-yield questions using Free MRCP MCQs or simulate exam conditions with a mock test.


Common pitfalls (5 bullets)

  • Mistaking Brugada for anterior STEMI

  • Missing subtle delta waves in WPW

  • Ignoring PR interval when assessing QRS width

  • Assuming all wide QRS complexes indicate bundle branch block

  • Prescribing AV nodal blockers in WPW with AF

MRCP Part 1 ECG revision setup with printed ECG strips and notes for Brugada and WPW pattern recognition

FAQs

1) How can I quickly recognise Brugada syndrome?

Focus on V1–V3 leads. A coved ST elevation with T-wave inversion is diagnostic of Type 1 Brugada.

2) What is the hallmark ECG feature of WPW?

The delta wave—a slurred upstroke of the QRS complex—combined with a short PR interval.

3) How is WPW different from bundle branch block?

WPW shows a short PR interval, whereas bundle branch block has a normal PR interval.

4) Why are AV nodal blockers dangerous in WPW?

They can increase conduction via the accessory pathway, leading to life-threatening ventricular arrhythmias.

5) Is Brugada ECG always present?

No, it can be intermittent and may be triggered by fever or medications.


Ready to start?

Master ECG spot diagnoses through repetition and pattern recognition. Start with the MRCP Part 1 overview, reinforce with Free MRCP MCQs, and assess your readiness using a mock test. For further ECG revision, pair this with a related post on ECG intervals and axis interpretation.


Sources

 
 
 

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