Calcium Channel Blockers-MJ

Question 1

What happens in the blood vessels when calcium channels are blocked?

Answer 1

Contraction will be prevented and vasodilation will result

Question 2

What are the three areas in the heart that have calcium channels?

Answer 2

Myocardium, SA node, AV node

Question 3

Calcium channels at all three sites in the heart are coupled to _____ receptors

Answer 3

Beta1 adrenergic receptors

Question 4

Calcium flow in the myocardium increases force of contraction. If the calcium channels in the atrial and ventricular muscle are blocked, ______ will diminish.

Answer 4

Contractile force

Question 5

What is the pacemaker (SA node) activity of the heart regulated by?

Answer 5

Calcium

Question 6

When calcium channels are open in the SA node, spontaneous discharge of the SA node increases. What happens when we block the calcium channels?

Answer 6

Pacemaker activity declines resulting in reduced HR

Question 7

Since impulses from the SA node must pass through the AV node on the way to the ventricles, regulation of AV conduction plays a critical role in ________.

Answer 7

Coordinating contraction of the ventricles with contraction of the atria

Question 8

What is the excitability of AV nodal cells regulated by?

Answer 8

Calcium entry

Question 9

In the AV node, when calcium channels are open, calcium entry increases and the cells of the AV node discharge more readily. What happens when we block those calcium channels?

Answer 9

Discharge of AV nodal cells is depressed so there is a decrease velocity of conduction through the AV node

Question 10

What are the two areas where calcium channels are found?

Answer 10

Blood vessels and heart (myocardium, SA node, AV node)

Question 11

What are the two types of calcium channel blockers?

Answer 11

Dihydropyridines and non-dihydropyridines

Question 12

What calcium channels receptors do the dihydropyridines block?

Answer 12

Blood vessel ones ONLY

Question 13

What calcium channel receptors do the non-dihydropyridines block?

Answer 13

BOTH the blood vessel and heart receptors!

Question 14

What are the 3 drugs of the dihydropyridines?

Answer 14

• Nifedipine XL
• Amlodipine
• Amlodipine/ Benazepril

Question 15

What are the indications for giving a dihydropyridine medication?

Answer 15

Hypertension

Angina pectoris

Question 16

What are the 2 non-dihydropyridines medications?

Answer 16

Verapamil

Diltiazem

Question 17

What are the indications for giving a non-dihydropyridine medication?

Answer 17

Hypertension

Angina pectoris

A-fib

Question 18

What are the adverse effects of ALL calcium channel blockers?

Answer 18

• Dose dependent peripheral edema
• Headache
• Flushing
• Dizziness

Question 19

If a patient who is on a CCB comes in and complains that his shoes don’t fit anymore, what adverse effect is that patient experiencing?

Answer 19

Dose dependent peripheral edema

Question 20

The dihydropyridines have an adverse effect that the non-dihydropyridines don’t have. What is that adverse effect?

Answer 20

Reflex tachycardia

Question 21

Even though other dihydropyridines can cause reflex tachycardia, it usually is only seen with what type of medication, which is ___?

Answer 21

Medications that are IR (immediate release); Nifedipine IR

Question 22

Is reflex tachycardia potentially dangerous. Why or why not?

Answer 22

Yes, it can lead to an MI

Question 23

If you are on a CCB that could cause reflex tachycardia, what other drug could you take to suppress the reflex tachycardia?

Answer 23

Beta blocker

Question 24

What are the 4 adverse effects seen with the non-dihydropyridines ONLY?

Answer 24

• Bradycardia
• CYP34A interactions
• Constipation
• Avoid with heart failure or blocks!!!

Question 25

Constipation is one of the adverse effects of the non-D drugs. Which drug primarily causes constipation?

Answer 25

Verapamil

Question 26

Why are diltiazem and verapamil (both non-D drugs) dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks?

Answer 26

These drugs have cardiosuppressant effects. Blockade of the calcium channels in the heart can compromise cardiac function

Question 27

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks because blockade of calcium channels in the heart compromises cardiac function. What happens to these patients when there is blockage of calcium to the SA node?

Answer 27

Bradycardia

Question 28

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks because blockade of calcium channels in the heart can compromise cardiac function. What happens to these patients when there is blockage to the AV node?

Answer 28

Partial or complete AV block

Question 29

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV block because blockade of calcium channels in the heart can compromise cardiac function. What happens to patients when there is blockage in the myocardium?

Answer 29

Decrease contractility

Question 30

If the heart is healthy, the blockage to the SA node, AV node, or myocardium rarely will have clinical significance. But if you have heart failure, sick sinus syndrome, or third-degree AV block, diltiazem and verapamil can seriously excerbate dysfunction. These two drugs should be used with CAUTION in patients with \_\_\_\_\_. These two drugs MUST NOT BE USED in patients with \_\_\_\_\_\_\_\_.

Answer 30

Used with caution in patients with cardiac failure Must not be used in patients with sick sinus syndrome, second-degree or third-degree AV block

Question 31

SA node is the pacemaker of the heart. It discharges and impulses spread rapidly throughout the ____ along the intermodal pathways. What does this rapid conduction allow?

Answer 31

Atria; allow the atria to contract in unison

Question 32

AV node: Impulses from the atria must pass through the AV node to reach the \_\_\_.

Answer 32

Ventricles

Question 33

AV node: In the healthy heart, impulses arriving at the AV node are delayed before going on to excite the ventricles. Is this delay normal? Why or why not?

Answer 33

Yes it is normal; it provides time for blood to fill the ventricles before ventricular contractions

Question 34

What are the function of the fibers of the His-Purkinje System?

Answer 34

Conduct electrical excitation very rapidly through all parts of the ventricles

Question 35

His-Purkinje System: Impulses leaving the ___ stimulate the His-Purkinje System.

Answer 35

AV node

Question 36

His-Purkinje System: Impulses conducted rapidly down bundle of His enter the right and left bundle branches and distribute to the branches of the Purkinje fibers. These impulses travel quickly so all regions of the ventricles are stimulated almost simultaneously. What does this all produce?

Answer 36

Synchronized ventricular contractions with resultant forceful ejection of blood