[Clinical aspects of polymorphic ventricular tachycardia]

Area of Science:

• Cardiology
• Electrophysiology

Context:

• Polymorphic ventricular tachycardia presents with dynamic QRS morphology on electrocardiograms.
• Diagnosis is complicated by varying presentations and the potential unavailability of resting ECGs in emergencies.
• Underlying cardiac conditions and drug therapies influence the specific type and management of polymorphic ventricular tachycardia.

Purpose:

• To define polymorphic ventricular tachycardia and highlight its diagnostic challenges.
• To classify different entities of polymorphic ventricular tachycardia based on clinical and electrocardiographic features.
• To emphasize the critical role of clinical context in diagnosis and treatment decisions.

Summary:

• Polymorphic ventricular tachycardia involves constant changes in QRS morphology, necessitating accurate diagnosis due to significant etiological, therapeutic, and prognostic implications.
• Classification includes Torsades de Pointes (long QT, short coupling interval) and catecholamine-induced VT in children, alongside iatrogenic forms and VT in infarction/other cardiac diseases.
• The clinical context, rather than solely the resting ECG, is paramount for diagnosis and treatment, particularly in emergency settings. Programmed ventricular stimulation-induced VT is also discussed.

Impact:

• Improved diagnostic accuracy for polymorphic ventricular tachycardia.
• Enhanced understanding of the diverse etiologies and classifications of polymorphic ventricular tachycardia.
• Guidance for clinicians in managing polymorphic ventricular tachycardia, especially in critical care scenarios.