Free USMLE USMLE Exam Questions

Emphysema is not linked to which of the following terms? 

A 54-year-old man comes to the physician because of episodes of fainting for 3 months. He also has had difficulty performing daily tasks because he is easily fatigued. He had a myocardial infarction 12 years ago. His pulse is 40/min, respirations are 18/min, and blood pressure is 138/85 mmHg. Physical examination shows evidence of cannon a waves. An ECG shows a P-wave rate of 90/min, and an R-wave rate of 40/ min, with no apparent relation between the two. Which of the following is the most likely diagnosis?

Another name for Vitamin B12 is ____. 

A 55-year-old man is brought to the emergency department because of shortness of breath and confusion for 4 hours. He has hypertension and chronic kidney disease requiring hemodialysis. An ECG shows low voltage with electrical alternans. Physical examination is most likely to show which of the following findings?

During phase 3 of the myocardial action potential which ion is moving the most?