This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmia 3, Subject name: Medicine
A patient has presented with palpitations. There no past history of any similar episode(s) but he informs you that he consumed a large amount of coffee at work. What is the most appropriate first-line treatment for this patient? 
Select and explain. 
A. Vagal maneuvers, B. Intravenous adenosine, C. Catheter ablation, D. Cardioversion
A: Vagal maneuvers
Answer: A: Vagal maneuvers 
Explanation: Dx for this case is PSVT -ECG HR=150 beats/minute No P wave Narrow QRS Option A: Vagal maneuvers- first line treatment for PSVT Option C: Catheter ablation used when Patient have recurrent episodes of PSVT, when patient have recurrent Tachyarrhythmia Option D: Cardioversion is given to patient who have syncope or Hemodynamically unstable & here only palpitation is presentation so ruled out.