ECG Challenge: Heart Patient With a Racing Pulse
ECG Challenge: Heart Patient With a Racing Pulse
Published: July 18, 2025
Source: Medscape
Key Scientific Takeaways:
1. Diagnosis: Ventricular Tachycardia (VT)
• Confirmed by ECG interpretation and AV dissociation; correctly identified by 56% of peers.
2. ECG Findings:
• Regular tachycardia at 132 bpm
• Wide QRS duration (0.16 sec), resembling but atypical for RBBB
3. Axis Deviation:
• Extreme left axis deviation (positive in lead I, negative in II/aVF)
4. AV Dissociation:
• Occasional P waves occur independently from QRS complexes → confirms AV dissociation, a hallmark of VT.
5. ST-T Wave Abnormalities:
• Reflects aberrant ventricular activation and possible superimposed P waves.
6. QT Interval Analysis:
• QT/QTc measured at 380/560 ms, but normalized to 300/445 ms when adjusted for wide QRS.
7. Consideration of Fascicular VT:
• RBBB-like morphology + left axis → might suggest left posterior fascicular VT
• Yet, history of CAD and MI makes ischemic VT far more likely
8. Pathophysiology of VT:
• VT arises from reentrant circuits within ventricular tissue, bypassing the His–Purkinje system, causing abnormal conduction and ECG changes.
Conclusion:
A wide-complex tachycardia with AV dissociation and abnormal axis/QRS features confirms ventricular tachycardia in a patient with coronary artery disease and previous MI.