QRS complexes in ventricular rhythms should be ________ seconds wide

After assisting a patient with the use of an epinephrine auto-injector, you note that the patient's blood pressure has improved. As a knowledgeable EMT, you realize that this has occurred due to epinephrine's ability to:

A) relax the smooth muscle of the blood vessels. B) constrict blood vessels. C) increase the number of circulating red blood cells. D) increase the oxygen-carrying capacity of the red blood cells.

R-R intervals that exhibit no similarity are termed:

A) irregularly irregular B) occasionally irregular C) regularly irregular D) regular