Chapter 26- antiarrhythmics

Question 1

CLASS ONE

Answer 1

• sodium channel blockers
• VENTRICULAR
• LIDOCAINE
• mainly used to treat life threatening ventricular arrhythmias
• fallen out of use due to side effects

Question 2

CLASS TWO

Answer 2

BETA BLOCKERS
ATRIAL&Ventricular
“olol”

• reduce or block SNS stimulation to the heart and transmission of impulses in the cardiac conduction system- affect mostly slow tissue
• main value of BBs is to treat atrial dysrhythmias associated with heart failure
• contraindicated in clients with heart block, sever bradycardia, AV block, and ASTHMA, DIABETES (masks signs of hypoglycemia)
• adverse effects are hypotension, bradycardia, bronchospasms
• monitor for WEIGHT GAIN (report weight gain of 2 or more a week; take med with meals; do not take if pulse is less than 60)

Question 3

CLASS THREE

Answer 3

POTASSIUM BLOCKERS
ATRIAL AND VENTRICULAR
“one” (amiodarone)

• increase action potential duration and affect fast tissue
• contraindications in bradycardia, heart block, cardiogenic shock, pregnancy
• adverse effects of amiodarone- PHOTOSENSITIVITY (wear sunscreen) and PROLONGING QT conduction in heart which causes arrhythmias and can cause visual changes
• reserved for serious dysrhythmias
• drug interactions (digoxin and warfarin)
• adverse effects: PULMONARY FIBROSIS (assess lung sounds for crackles; crackles sounds like velcro or shoveling snow)

Question 4

CLASS FOUR

Answer 4

“pine”
CALCIUM CHANNEL BLOCKERS
ATRIAL

• blocks and slows channels or calcium; dependent channels
• contraindications- heart block, bradycardia, CHF, hypotension, pregnancy
• adverse effects: hypotension, CHF, EDEMA, GI symptoms, dizziness, fatigue, headache
• AVOID IV beta blockers with IV CCB
• MONITOR WEIGHT while on this med
• do not give if pulse is less than 60

Question 5

-nursing implications/teaching for class two

Answer 5

• report weight gain of 2 or more in a week
• take meds with meals
• do not take if pulse is less than 60

Question 6

-nursing implications/teaching for class III

Answer 6

-use sunscreen due to photosensitivity

Question 7

nursing implications/teaching for class IV

Answer 7

• do not take if pulse if less than 60/min

- avoid grapefruit juice

Question 8

for all antiarrythmics notify MD if…

Answer 8

-notify MD immediately if patient has increased SOB, edema, chest pain, dizziness, or syncope

Question 9

sodium channel blockers (the way they work)

Answer 9

• block sodium channels (preventing depolarization of the cell by blocking influx of sodium)
• slows impulse conduction across heart
• treat VENTRICULAR dysrhythmias
• have potential to create new dysrhythmias or worsen existing ones
• causes hypotension, dizziness, and syncope

Question 10

lidocaine

Answer 10

• sodium channel blocker
• accelerates repolarization; decreases duration of action potential
• if someone is allergic to lidocaine, they CAN take procainamide

Question 11

procainamide

Answer 11

sodium channel blocker

• delays repolarization
• increases duration of action potential

Question 12

beta-adrenergic antagonists/blockers (class II) (how they work)

Answer 12

• slow heart rate and decrease conduction velocity through the AV node
• myocardial automaticity is reduced
• ATRIA AND VENTRICULAR
• adverse effects: bradycardia, hypotension, dizziness, syncope, BRONCHOSPASM (don’t give to patients with asthma)
• abrupt discontinuation of beta blockers can lead to dysrhythmias and hypertension

Question 13

propanolol (inderal)

Answer 13

• beta-adrenergic antagonist (beta blocker)
• class II
• reduces heart rate, slows myocardial conduction velocity, lowers blood pressure
• affects beta1 receptors in heart and beta2 receptors in pulmonary and vascular smooth muscle
• use cautiously in patients with DIABETES (propanolol may “mask” symptoms of hypoglycemia because the adrenergic “fight-or-flight” response to hypoglycemia is blocked)

Question 14

potassium channel blockers (how they work)

Answer 14

-by blocking potassium channels, K+ is not able to come back into the cell and repolarization of the cell is therefore delayed
-prolong duration of action potential and reduce automaticity
-lengthen refractory period
-reserved for serious dysrhythmias
ATRIAL AND VENTRICULAR
-limited use due to serious adverse effects such as bradycardia and hypotension
-PCB can worsen dysrhythmias

Question 15

amiodarone

Answer 15

-Potassium channel blocker (class III)

• blocks potassium ion channels
• can produce pulmonary toxicity (pneumonia like syndrome)
• photosensitivity

Question 16

calcium channel blockers

Answer 16

-class IV
-blocks calcium channels in both the heart and arterioles
-slows conduction velocity
-reduced automaticity in the SA node and SLOWED IMPULSE CONDUCTION through the AV node
-slows heart rate and prolongs refractory period
VENTRICULAR
-adverse effects: bradycardia and hypotension

Question 17

cardizem and verapamil (Calan)

Answer 17

• blocks calcium channels in heart and arterioles
• inhibits transport of calcium into myocardial cells
• relaxes coronary and peripheral blood vessels, bringing more oxygen to the myocardium and reduces cardiac workload
• adverse effects: headache, dizziness, and EDEMA

Question 18

miscellaneous drugs for dysrhythmias

Answer 18

DIGOXIN

Question 19

digoxin

Answer 19

-ability to suppress the SA node and slow electrical conduction through the AV node

• seeing halos
• digoxin interacts with many meds
• digoxin toxicity can be common
• check apical pulse for one minute before administration
• check for serum digoxin levels before administering