Cardiology MCQ 18.4.15

Cardiology MCQ & Review

All of the following statements about fascicular reentry ventricular tachycardia are true except

A. Fascicular VTs  account for around 10% of idiopathic VTs

B. Left posterior fascicular VT is the most common, with a narrow right bundle, left inferior axis QRS morphology.

C. Left anterior fascicular VT is less common and has right bundle, right inferior axis QRS morphology.

D.  These tachycardias are also referred to as verapamil-sensitive fascicular tachycardias, given their tendency to slow or terminate with intravenous verapamil.

Explanation:

-Most patients with VT have structural heart disease, 10% have idiopathic VT, occurring in the setting of a structurally normal heart

-Among idiopathic VTs, those arising from the right or left ventricular outflow tract are most common, followed by fascicular VT, which accounts for between 7% and 12% of idiopathic VTs

-Left posterior fascicular VT is the most common, with a narrow right bundle left superior axis QRS morphology.
-Left anterior fascicular VT is less common and has right bundle right inferior axis QRS morphology

-These tachycardias are also referred to as verapamil-sensitive fascicular tachycardias, given their tendency to slow or terminate with intravenous verapamil
-Fascicular VT typically manifests in young adulthood with a slight male preponderance

-Presentation consists of palpitations, presyncope and, rarely syncope, but not sudden cardiac death

-Incessant, fascicular VT has been reported to cause tachycardia-mediated cardiomyopathy

-In some patients, the arrhythmia may manifest only during exercise.

References:

1. Tada H, Ito S, Naito S, et al: Idiopathic ventricular arrhythmia arising from the mitral annulus: A distinct subgroup of idiopathic ventricular arrhythmias. J Am Coll Cardiol 45:877–886, 2005.
2. Lin D, Hsia HH, Gerstenfeld EP, et al: Idiopathic fascicular left ventricular tachycardia: Linear ablation lesion strategy for noninducible or nonsustained tachycardia. Heart Rhythm 2:934–939, 2005.
3. Belhassen B, Rotmensch HH, Laniado S: Response of recurrent sustained ventricular tachycardia to verapamil. Br Heart J 46:679–682, 1981.
4. Bennett DH: Experience with radiofrequency catheter ablation of fascicular tachycardia. Heart 77:104–107, 1997.
5. Nakagawa H, Beckman KJ, McClelland JH, et al: Radiofrequency catheter ablation of idiopathic left ventricular tachycardia guided by a purkinje potential. Circulation 88:2607–2617, 1993.
6. Lee HW, Kim JB, Joung B, et al: Successful catheter ablation of focal automatic left ventricular tachycardia presented with tachycardia-mediated cardiomyopathy. Yonsei Med J 52:1022–1024, 2011.

Answer: B (Left posterior fascicular VT has right bundle branch and left superior axis )

Keywords: Cardiology review, Cardiology, Multiple choice questions, medical students, Electrophysiology, Ventricular tachycardia

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