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Difficulty: MediumCardiovascular System

A 2424-year-old male is being evaluated in the cardiology clinic after experiencing an episode of syncope while playing basketball. He has a family history of a sudden, unexplained death in a maternal uncle at age 3535. The evaluation of syncope often hinges on recognizing specific electrocardiographic (ECG) patterns associated with an increased risk of sudden cardiac death. Match each of the following classic ECG findings with its most likely clinical diagnosis.

  • Coved ST-segment elevation ≥2\geq 2 mm in leads V1-V3 followed by an inverted T waveBrugada syndrome
  • Short PR interval (<120< 120 ms), widened QRS complex, and a slurred initial upstroke of the QRS (delta wave)Wolff-Parkinson-White syndrome
  • Small positive deflection at the end of the QRS complex in the right precordial leads (epsilon wave) with T wave inversions in V1-V3Arrhythmogenic right ventricular cardiomyopathy
  • Corrected QT interval of 520520 ms without other structural heart abnormalities in a young patientCongenital long QT syndrome

Answer

Coved ST elevation matches Brugada syndrome; Delta wave matches Wolff-Parkinson-White syndrome; Epsilon wave matches Arrhythmogenic right ventricular cardiomyopathy; Prolonged QTc matches Congenital long QT syndrome.
Each specific ECG finding correlates directly with the underlying pathophysiology of distinct arrhythmogenic syndromes: Brugada syndrome (coved ST elevation in V1-V3 due to Na+ channelopathy), Wolff-Parkinson-White (delta wave due to accessory pathway), ARVC (epsilon wave due to RV fibrofatty replacement), and Congenital long QT syndrome (prolonged repolarization).

Step-by-Step Solution

1
Analyze the first ECG description: coved ST-segment elevation in V1-V3.
This pattern is highly specific for Brugada syndrome, a channelopathy causing ventricular arrhythmias.
Identifying the characteristic right precordial ST elevation isolates the diagnosis of Brugada syndrome.
2
Analyze the second ECG description: short PR, widened QRS, and a delta wave.
This triad defines ventricular pre-excitation, which is the hallmark of Wolff-Parkinson-White (WPW) syndrome.
The accessory pathway bypasses AV nodal delay, causing the short PR and the initial slurred ventricular depolarization (delta wave).
3
Analyze the third ECG description: epsilon wave and T wave inversions in V1-V3.
The epsilon wave indicates delayed right ventricular activation, mapping to Arrhythmogenic right ventricular cardiomyopathy (ARVC).
Fibrofatty infiltration of the right ventricle in ARVC causes localized conduction delays seen as epsilon waves.
4
Analyze the fourth ECG description: prolonged QTc in an otherwise healthy patient.
A QTc of 520 ms without structural disease or secondary causes points to Congenital long QT syndrome.
Ion channel mutations prolong the action potential duration, increasing the risk for Torsades de pointes.

Key Concept

Electrocardiographic diagnosis of arrhythmogenic syncope and sudden cardiac death syndromes
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Topics

Cardiovascular System

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