Long QT Syndrome ECG Example
Figure 1: Long QT Syndrome - Characteristic ECG Pattern
🔑 Key Points at a Glance
- Heart Rate: Variable, often bradycardia
- Primary Significance: High risk of torsades de pointes and sudden cardiac death, congenital or acquired
- Key Management: Identify and correct reversible causes (electrolytes, medications), beta-blockers for congenital, consider ICD, avoid QT-prolonging drugs
- Clinical Category: Clinical
Overview and Clinical Significance
Long QT Syndrome represents a critical cardiac rhythm pattern that requires immediate recognition and intervention. High risk of torsades de pointes and sudden cardiac death, congenital or acquired
Understanding this ECG finding is essential for emergency physicians, cardiologists, intensivists, and all healthcare providers involved in acute cardiac care. Early recognition and appropriate management can significantly impact patient outcomes and prevent life-threatening complications.
ECG Characteristics and Recognition
📊 Diagnostic ECG Criteria
- Prolonged QT interval (QTc >450ms men, >460ms women)
- Abnormal T wave morphology
- T wave notching
- Prominent U waves
Systematic ECG Analysis Approach
When analyzing any ECG, including suspected Long QT Syndrome, follow this systematic approach:
- Rate: Calculate ventricular rate using the 300-150-100-75-60-50 rule or count QRS complexes in 6 seconds × 10
- Rhythm: Assess regularity by measuring R-R intervals across the entire strip
- P Waves: Identify presence, morphology, and relationship to QRS complexes
- PR Interval: Measure from start of P wave to start of QRS (normal: 0.12-0.20 seconds or 3-5 small squares)
- QRS Complex: Assess duration (normal: Always assess hemodynamic stability FIRST - unstable patients require immediate intervention regardless of the specific ECG diagnosis
Evidence-Based Management
Acute Management Strategy
Primary Treatment Approach: Identify and correct reversible causes (electrolytes, medications), beta-blockers for congenital, consider ICD, avoid QT-prolonging drugs
🚨 Emergency Protocol - Time-Critical Actions
- Immediate ABC assessment (Airway, Breathing, Circulation)
- Attach continuous cardiac monitoring and obtain 12-lead ECG
- Establish large-bore IV access (×2) and check bedside glucose
- Administer supplemental oxygen if SpO₂ Recommendations for management of Long QT Syndrome are primarily supported by Level A evidence (multiple high-quality randomized controlled trials and meta-analyses).
Summary and Clinical Bottom Line
📋 Clinical Bottom Line
Long QT Syndrome is characterized by prolonged qt interval (qtc >450ms men, >460ms women) on ECG. High risk of torsades de pointes and sudden cardiac death, congenital or acquired Primary management: Identify and correct reversible causes (electrolytes, medications), beta-blockers for congenital, consider ICD, avoid QT-prolonging drugs Key takeaway: This is a life-threatening emergency requiring immediate recognition and treatment - time-critical intervention saves lives
About the Author
Dr. Raj K
Emergency Medicine Physician Dr. Raj K is a board-certified Emergency Medicine physician with extensive experience in acute cardiac emergencies, advanced ECG interpretation, and critical care. He is passionate about medical education and bringing evidence-based emergency medicine knowledge to healthcare providers worldwide through E-PulsePoints. His clinical expertise includes STEMI management, complex arrhythmia recognition, and emergency cardiac procedures.
