Chapter 27 Lecture Video

Alright students now we're going to cover chapter 27

drug therapy for dis arrhythmias.

So um anti dis arrhythmic agents are medications that

we use to prevent or treat cardiac dysrhythmia.

So a dysrhythmia is an abnormal abnormal heart rhythm or

heart rate and it interferes with the cardiac function.

So the heart will not be able to pump

adequately and would cause inadequate profusion to the tissues.

The heart is a

electrical pump. You can think of the heart as um

you know, it pumps blood to the whole body and it has um

several things that can occur

and it basically

there's the blood flow that's that

goes through the heart and is available to the heart and

then there's the blood that is carried away from the heart.

In addition we have the electrical system

of the heart has its own electrical activity

and so it can generate and conduct electrical impulses.

Um and that's what regulates the heart and the pumping function.

So some things can go wrong with this component of the heart.

Normal synchronized activities result in an effective cardio

contraction and distribution of blood throughout the body.

H. R. B. It occurs at regular intervals and kisses of four events.

First you have stimulation from electrical

impulse transmission of the electrical impulse to

adjacent conduct over contract all tissues and then contraction of the atria,

followed by the ventricles,

then relaxation of atrial and then the ventricles

which is and this process continues over and over it with each heartbeat.

Automaticity is the heart's ability to generate its its own electrical impulse

initiation of electrical impulse depends on the

movement of the sodium and calcium channel um

ions in the myocardial cell and the movement of potassium ions out of the cell,

the movement of ions changes the membrane from its

resting state to an electrical of electrical neutrality.

To inactivate the state of electrical energy build up

after the electrical energy is discharged, which is called deep polarization.

The muscle contracts itself.

The ease in which cardiac muscle responds to

the series of events is called cardiac excitability.

And um you know, the electrical impulse moves across the heart.

You can think of it moving from the top to the bottom.

And that's why in the atrium at the top of the heart and the ventricles at the bottom

conductivity is the ability of the cardiac tissue

to transmit electrical impulses.

Normally,

the electrical impulses originate in the S. A.

Note and transmit through the international

politics to the atrial ventricular note.

This is the normal process.

The impulse is delayed for a brief period and that's

for the blood to pump through the part adequately.

The impulse travels to the bundle of his bundle

branches poking the fibers and through the ventricular muscles.

Dysrhythmia are when there's a problem of any part

of the conduction system in the atrium or ventricle.

They were result from disturbances in the electrical impulse information,

which is automaticity.

So the generation of that um regular heartbeat conduction,

which is the movement of the electricity through the heart

or both.

A topic means abnormal conduction arising anywhere other than the S. A. Note,

heart cells can

um being on their own or generate an electrical impulse

When the S. A. Note is not functioning properly.

However, it will not be at the normal rate.

The impulse impulse generation of alternate pacemaker

site with an essay node failure often results in a brady dysrhythmia.

So when the another cell and the heart takes over,

it generally will not be at the adequate heart rate and it will be slow

in many cases an ectopic pacemaker over writing

the essay node results in a tacky arrhythmia.

This can also happen

conduct and that will overtake the S. A note.

That would be that s a note probably is still

functioning but for some reason this um ectopic abnormal pacemaker.

It takes over and it produces a fast heart rhythm. The tacky dysrhythmia

conditions such as hypoxia ischemia.

Hypoxia ischemia may activate ectopic stimuli leading

to potentially serious impairment of cardiac function.

Just for the means can interfere with mechanical cardiac function and alter

alter the heart's ability to pump sufficient blood to the body tissues.

And these can affect the rate and rhythm

of contraction which impact impact the cardiac output.

Tech Arrhythmias. Our heart rates greater than 100 beats per minute.

And you can think about the, you know

the heart needs adequate, the chambers need adequate time to fill.

And when we are heart rate is too fast that that does not occur.

And so it can cause um cause a disfunction in

that cardiac output which would affect how the person feels.

And they can have symptoms from that

Brady and dis arrhythmias are those when when the heart rate is less than 60 beats per

minute and when it gets low enough the patient will have symptoms and may even faint.

Um um And we'll talk about that in a minute.

But um so it's you know 22 ends of the spectrum that um

are not normal and can cause symptoms and

dangerous things to happen to the patient

on both ends of the spectrum. Clinical manifestation of dis arrhythmias.

They may be asymptomatic or symptomatic the patient.

Um Sometimes that does happen where someone comes in and their heart is

just racing along or going slow and they feel perfectly fine and that's

um that can't happen usually.

Sometimes it's when the patient has had it for a while and has kind of accommodated.

Um But um some people are just not as sensitive to those changes.

The patient may perceive them as they may feel like I have.

They have palpitations or skipped heartbeats.

Um More severe may produce the following manifestations including

low blood pressure.

Um Obviously we'll notice we'll see either a slow heart rate or fast

heart rate when we're assessing them or looking on the cardiac monitor.

Um And a regular rhythm on the

monitor.

The patient may demonstrate shortness of breath um difficulty breathing, cough.

They may faint. They even feel lightheaded, they may feel confused chest pain.

Um And if they have had this going on for

a certain amount of time with decreased cardiac output either

from the fast heart rhythm like I talked about or

the low heart rate which doesn't produce enough profusion.

They may have alexandria which is um decreased urine output

because the member,

I have told you in the past that kidneys are very sensitive

to not getting enough blood and then they'll start shutting down.

Okay now norma

pharmacological management.

So sometimes things can be done to to to stop these dis arrhythmias.

Um Management without the use of drugs may be

preferable at least initially for several dis arrhythmias.

The Vassallo manure or other measures.

Um Are you can be used in certain situations for certain arrhythmias.

Um And that might knock them out of the

arrhythmia but it's really specific for a certain type

dysrhythmia drugs can worsen existing dis arrhythmias.

So we are we use costume when we use these medications.

Um So they have to have we have to have a good reason to use them

pacemakers and defibrillators.

Um

Can we use to treat dis arrhythmias.

Um We have um temporary pacemakers as well

as permanent pacemakers defibrillators are used often in

an emergency situation or they have implanted defibrillators

in people that have shown to have fatal

repeated with fatal arrhythmias or risk for it.

ablation is actually a procedure where they can

go into the heart with a catheter and actually

destroy or burn the abnormal um pacemaker ectopic

pacemaker to permanently get rid of that dysrhythmia.

So drug therapy all drugs used to treat disabilities

um alter the electrical conduction system of the heart.

They may reduce the automaticity.

So the conduction of electrical impulses through the heart

or prolong the refractory periods of my cardio cells

which is the period where they can't receive it like an electrical impulses

at that time.

Anti dis rhythmic therapy is commonly indicated for the following condition

for conversion of atrial fibrillation or

atrial flutter back to normal sinus rhythm

for maintaining

um normal sinus rhythm after an electrical conversion from a fib or a flutter

for suppression of faster regular ventricular rates.

Uh And for presence and and during

the situation where they have a dangerous dysrhythmia

first we'll talk a little bit about Class one sodium channel blockers.

Class one A queen nadine.

Um

It this medication is not used as much anymore but this

is a prototype doug and you can probably more often see

kind of minor just pira mean

at the bottom. But we'll talk about this.

It reduces automaticity and slows

conduction throughout the cardiac system through

direct or indirect anti Colin ergic effect on the cardiac tissue

reducing my cardio contract ill itty it prolongs

the refractory period of their myocardial cells.

Adverse effects changes can cost DNS changes.

It can be pro arrhythmic causing other dis arrhythmias

can cause stomach changes. Gi upset gemological changes and um

hypersensitivity alterations.

What does the nurse need to do assess for second

or third degree heart block or prolonged QT syndrome.

And these can be picked up on E. K. G.

We want to um make sure they're not.

No we haven't noticed any situations of

myasthenia gravis pregnancy lactation or their messiah

pina prepared because they can't be on this and assess if it's working.

Then we have class one sodium channel blockers. Class one B.

Which the prototype drug is lidocaine,

lidocaine

is

is still used today.

It's used to treat serious ventricular dysrhythmia.

It decreases myocardial variability which is the automaticity in

the ventral hills by increasing the electrical stimulation threshold

of the ventricular myocardial cells.

We have to monitor when we give this.

Usually it's given intravenously in the hospital setting.

Ah There we have 30 people collaterals of 1.5 to 5 mics per M. O.

And so we do monitor the levels on this one.

So they don't become toxic.

Class one sodium Channel Blockers. Class one C.

Um basically um

um have no effect on the preservation phase

but slow the conduction velocity and refractory period.

Um We have flak flak. Can

tonight

I'm sorry

can tonight

which is like a night and papa phenomenon

or oral ancients that increase the conduction.

The ventricle.

These drugs were

continuous kg monitoring.

Um Usually while the patient's getting um they can take this um

um

afterwards but it has to be initiated the hospital.

They increase the risk of

increase again accused the risk of non fatal

cardiac arrest. A death in

um patients with recent m I are my card

I'm sorry chronic atrial fibrillation

and also can have

fatal

proudest arrhythmic effects.

Okay.

Class to beta and dramatic blockers for panel All inter

all we've learned a little bit about beta blockers.

This medication is not not as much um not as

serious as some of the others that we've already talked about

it some more um You know used often in the um

for various things and it's pretty safe.

It completely blocks speed. Editor receptors in the heart

and the judge stone

apparatus.

It um causes a decrease in the influence influence of sympathetic nervous system

on the tissues and a decrease in the excitability of the heart,

cardiac workload and oxygen consumption

symptoms. Side effects.

We do worry about um It can cause um

some pulmonary things um we worry about bradycardia.

We have to monitor the heart rate. Make sure they're not getting too slow.

Um They can have um low blood pressure

or like the pulmonary stuff the bronco spasm.

So someone with asthma might not be a candidate for this

other drugs in this class would be soda law and s Malone

um

Which I have a little bit more

side effect

than than this one

but maybe work a little bit better for certain of its use.

Then we have the class three potassium channel blockers.

amiodarone is the medication used very frequently in the hospital.

It's kind of overtaking lidocaine.

Um And it's it's used to committees and inpatient outpatient setting. It's ivy or P.

O. It prolongs the duration of action potential.

And so it's very polarization.

It belongs to the factory period in both the teacher and the ventricle.

It does have a black box warning

for fatal dysrhythmia

and the development of potentially fatal pulmonary toxicity of product toxicity.

And we're seeing this arrhythmia.

So the person who's on this long term needs to be monitored for these things,

especially the pulmonary thing that they're not develop any symptoms of that.

Um

They says confused,

correct monitor is necessary and that would be in

for the intravenous infusion and not in the hospital.

But then once they're stabilized and they've changed the P. O.

They can go home on this if needed.

Um Did you um

nah jerome, sorry

Jonah Jonah Jonah which is will attack

um beautified, which is comfort and social

benefits or some other medications

um that are considered similar.

Okay. And then

um a class of four costume channel blockers. We have Cardizem

um which is delta autism.

We've learned, we learned about it a little bit for blood pressure control.

It's also

anti district Mick.

It obstructs the movement of calcium into

the conductive and contractual microcredit cells by human

the influx of calcium through its channels

causing a slower conduction to the essay.

And Navy notes.

Um It can cause lightheadedness, braided cardio a little bit pressure.

We have to monitor for these things.

Make sure that they're having

they have adequate heart rate and blood pressure Before in ministry.

And then we have some other medications which are unclassified. The identity seen.

It depresses connection navy node and is used to restore normal sinus rhythm.

A patient with paroxysmal super ventricular tachycardia.

It's sort of used like an emergency setting when

the patient has this arrhythmia and they're symptomatic.

We can give this I. V. Push

um usually helps break it.

Um It's given very fast and um and like the er setting or

I um I see you when the patients had a cardiac monitor.

Um And usually with the physician at the bedside um magnesium sulfate.

Um It's just with the regulator of the flow of the sodium potassium

and calcium ions across the membrane which

can prevent re initiation in particular.

Um

um

Take a card Ius

Mhm.

And then um for drug therapy and emergency resuscitation of adults.

I kind of mentioned a few of them that are sometimes used.

Initial management of cardiac arrest must include adequate ventilation.

High quality compression,

restoring circulating volume loss and identifying the casual

um the cause the causal event and then um the therapeutic engines.

We use our oxygen, epinephrine, atropine, singing background like lidocaine,

calcium chloride.

And then I would say probably replacing lidocaine is more amiodarone,

um which these are all used in the emergency situation too.

You know you've heard of a code

um The this is the medication often used to help in that situation

And um that would conclude the lecture on Chapter 27.

Chapter 27 Lecture Video

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