Author Question: What effects can be expected from parasympathetic stimulation of the heart? What will be an ideal ... (Read 38 times)

V@ndy87 · **on:** Jun 25, 2018

What effects can be expected from parasympathetic stimulation of the heart?

What will be an ideal response?

Question 2

The QRS complex associated with a third-degree AV block is always wide.

Indicate whether the statement is true or false

IRincones · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

Parasympathetic stimulation has the following actions: it slows the rate of discharge of the SA node, slows conduction through the AV node, decreases the strength of atrial contraction, and can cause a small decrease in the force of ventricular contraction.

Answer to Question 2

F
The site of block in a third-degree AV block may be the AV node or, more commonly, the bundle of His or the bundle branches. A secondary pacemaker (either junctional or ventricular) stimulates the ventricles; therefore the QRS may be narrow or wide, depending on the location of the escape pacemaker and the condition of the intraventricular conduction system.