The short-long-short-short sequence and polymorphic ventricular tachycardias storm

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Arrhythmias

Background:

• Polymorphic ventricular tachycardia (PVT) poses a significant risk of sudden cardiac death.
• Understanding the precise initiation mechanisms of PVT is crucial for effective treatment strategies.

Observation:

• A patient presented with recurrent PVT episodes.
• All PVT episodes were consistently preceded by a distinct short-long-short-short (S-L-S-S) cardiac cycle sequence.
• Paroxysmal atrial fibrillation was identified as the cause of the S-L-S-S sequence.

Findings:

• The S-L-S-S sequence was identified as the initiating mechanism for PVT in this patient.
• The proposed electrophysiological mechanism involves reentrant excitation, rather than early afterdepolarizations or triggered activity.
• Administration of amiodarone successfully restored and maintained sinus rhythm, preventing recurrence of both atrial fibrillation and PVT.

Implications:

• This case highlights the S-L-S-S sequence as a specific trigger for PVT.
• Reentrant excitation is suggested as the primary mechanism underlying S-L-S-S-induced PVT.
• Amiodarone may be an effective therapeutic option for patients with PVT initiated by this specific sequence.