Answer to Question 1
ANS: C
Thyrotoxicosis, which refers to the hypermetabolic clinical syndrome that results from serum ele-vations in thyroid hormone, can cause sinus tachycardia. Vomiting, hypothermia, and mediastinal tumors can cause sinus bradycardia.
Answer to Question 2
ANS: D
Ingestion of large quantities of coffee, which contains caffeine, can cause a healthy person to have premature ventricular beats.