A 26 yo graduate student in the history department schedules an appointment at the health plan because of palpitations for the past 2 weeks. He describes a continuous awareness of his heart beat in his left chest. The rhythm feels regular. He has not had other cardiovascular or systemic symptoms other than feeling distracted by the palpitation. He has been in good health and does not take any medication. He has been preparing to defend his thesis. On physical examination while the patient is experiencing palpitations the pulse is 76 and regular, BP 116/70, and temperature normal. The jugular veins are flat at 30 degrees and the carotid pulses are palpable and without bruits. Palpation and auscultation of the heart in the supine, left lateral decubitus, and seated leaning forward positions are normal. S1 and S2 are normal and regular and there are no murmurs. The thyroid gland is normal, the lung bases are clear, and there is no peripheral edema. The deep tendon reflexes are 2+.
Which of the following is the most likely diagnosis?
A. Premature ventricular beats
B. Paroxysmal supraventricular tachycardia
C. Medically unexplained symptom
E. Junctional rhythm