This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hea Sounds, Subject name: Medicine
A 10-year old child with Valvular hea disease on hea failure treatment, has the following ECG tracing. What is the diagnosis? 
Select and explain. 
A. Tall tented T wave, B. Ventricular bigeminy, C. Non paroxysmal atrial tachycardia with irregular AV block, D. Non paroxysmal atria tachycardia with regular AV block
B: Ventricular bigeminy
Answer: B: Ventricular bigeminy 
Explanation: Hea rate of the patient is 50bpm . ECG tracing shows normal sinus rhythm alternating with premature ventricular contraction. This is diagnostic of ventricular bigeminy which is the most common arrhythmia seen with digoxin toxicity.