Idiopathic verapamil-sensitive sustained left ventricular tachycardia

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Arrhythmias

Background:

• Idiopathic verapamil-sensitive left ventricular tachycardia (VT) presents with distinct electrocardiographic features.
• This type of VT is characterized by a right bundle-branch block morphology and narrow QRS duration.
• Fascicular tachycardia is often associated with early endocardial activation preceding the QRS complex.

Purpose of the Study:

• To describe the characteristic features of idiopathic verapamil-sensitive left ventricular tachycardia.
• To discuss the likely reentry mechanism underlying this arrhythmia.
• To highlight the efficacy of verapamil in managing this condition.

Main Methods:

• Analysis of electrocardiographic (ECG) findings during episodes of left ventricular tachycardia.
• Review of electrophysiological studies to understand the activation patterns.
• Clinical data review for treatment response and long-term outcomes.

Main Results:

• Characteristic QRS morphology includes right bundle-branch block with left or right axis deviation.
• QRS duration is typically narrow, ranging from 0.13 to 0.16 seconds.
• Endocardial activation preceding QRS is frequently observed, supporting the fascicular tachycardia classification.

Conclusions:

• Idiopathic verapamil-sensitive left ventricular tachycardia is likely caused by a reentry mechanism.
• The slow conduction properties differ from VT associated with structural heart disease.
• Chronic oral verapamil therapy is the primary treatment, leading to a good long-term prognosis.