A 29-year-old Caucasian female presents to the cardiologist for evaluation of syncope. Her symptoms are precipitated by long periods of standing and are characterized by a prodrome of...

A 29-year-old Caucasian female presents to the cardiologist for evaluation of syncope. Her symptoms are precipitated by long periods of standing and are characterized by a prodrome of light-headedness, loss of vision, and diaphoresis (excessive sweating). Her ECG strip shows a prolonged P-QRS interval, which is characteristic of which of the following?

A. Normal ECG

B. First degree AV block

C. Second degree AV block

D. Third degree AV block