Drug facts General

Atropine Cardio-action !

Atropine Functions as a Cardioaccelerator  , so it’s used for treatment of Bradycardia

How is that  ??

Before Atropine administration  :

When the neurotransmitter acetylcholine is released , it binds to cholinergic receptors causing a vagal stimulation

the vagus nerve acts on the sinoatrial (SA) node  and the atrioventricular (AV) node found in the Heart ,

and causes inhibition of the electrical conduction between the two Nodes ( SA & AV )

>> this causes the heart rate to slow down into :

Lub-dub . . . Lub-dub . . .  Lub-dub !!

After Atropine administration  :

Atropine act as a cholinergic blocking drug, so it competes with acetylcholine for cholinergic receptor sites on the SA and AV nodes.

and By blocking acetylcholine ;

– the Vagus nerve stimulation is decreased

– Conduction between the heart nodes ( SA & AV ) is enhanced ( less inhibited )

> > > > > This speeds up the heart rate into :

Lub-dub  Lub-dub  Lub-dub  Lub-dub  Lub-dub !!

~ . ~ . ~ . ~. ~. ~ . ~ . ~ . ~ . ~ . ~

Atropine also may be given to prevent cardiac arrest resulting from vagal reflex activation, incident to anesthetic induction , gastric lavage , or endoscopic procedures .

Ipratropium is used in bradycardia and AV-block to raise heart rate and to facilitate cardiac impulse conduction.

As it is a quaternary substance, it doesn’t penetrate into the brain,
which greatly reduces the risk of CNS disturbances caused by Atropine .

but relatively , high oral doses are required because of an inefficient intestinal absorption.


Hint :

A healthy heart makes a ” Lubdub”  sound with each beat.

This sound comes from the valves shutting on the blood inside the heart.

The first sound ” Lub ” happens when the mitral and tricuspid valves close after the blood has been pushed from atria into ventricles ,

while the next sound “ dub ” happens when the aortic and pulmonary valves close after the blood has been squeezed out of the heart .

you can listen to a sample of normal heart sounds in this animation :

Next time you go play with a stethoscope , try to listen to Your own lub-dub :wink:


References :

– Basic and clinical Pharmacology \\ chapter 8

– Color Atlas of Pharmacology

– Pharmacology – 4th edition

– introductory to clinical Pharmacology – 7th edition

 1,937 total views,  1 views today

0 0 vote
Article Rating
Notify of
Newest Most Voted
Inline Feedbacks
View all comments
Online Poker

ha, I am going to try out my thought, your post give me some good ideas, it’s truly amazing, thanks.

– Murk

COVID-19 Pandemic

Phartoonz.com would like to thank all the frontline healthcare workers including doctors, nurses, support staff, and cleaning staff for their tremendous tireless work and effort during this COVID-19 coronavirus pandemic. To stay up to date, always seek trusted sources about this pandemic

Would love your thoughts, please comment.x

Subscribe to get the latest Articles, Quizzes, mnemonics and lots more...

We hate spam too!

You have successfully subscribed to the newsletter

There was an error while trying to send your request. Please try again.

Phartoonz will use the information you provide on this form to be in touch with you and to provide updates and marketing.