This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Congenital long QT syndrome can lead to 
Select and explain. 
A. Complete hea block, B. Polymorphic ventricular tachycardia, C. Acute myocardial infraction, D. Recurrent supraventricular tachycardia
B: Polymorphic ventricular tachycardia
Answer: B: Polymorphic ventricular tachycardia 
Explanation: Polymorphic VT has a continually changing QRS morphology indi- cating a changing ventricular activation sequence. Polymorphic VT that occurs in the context of congenital or acquired prolongation of the QT interval often has a waxing and waning QRS amplitude creat- ing a "twisting about the points" appearance referred to as Torsade de Pointes Ref Harrison 20th edition pg 1445