CCB contraindication in ACS - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 2 CK Forum

USMLE Step 2 CK Forum USMLE Step 2 CK Discussion Forum: Let's talk about anything related to USMLE Step 2 CK exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-11-2010
USMLE Forums Veteran
 
Steps History: 1+CK+CS+3
Posts: 247
Threads: 61
Thanked 273 Times in 105 Posts
Reputation: 303
Heart CCB contraindication in ACS

I have got a ques ... where it said CCB is contraindicated in ACS ... as ccb causes vasodilation ... thus reflex tachycardia ... may worsen ischemia .... But we use GTN tho diff mechanism .. it also cause vasodilate thus can increase HR and ischemia .... GTN in initial drug in chest pain if suspect ACS ... why GTN is not contraindicated ..... as it may worsen ischemia too .... if someone know this , pls tell ......
Reply With Quote Quick reply to this message



  #2  
Old 05-11-2010
S.Martin's Avatar
USMLE Forums Scout
 
Steps History: Not yet
Posts: 34
Threads: 3
Thanked 20 Times in 11 Posts
Reputation: 30
Info Who said CCBs CIed in ACS!

Calcium Channel Blockers are not contraindicated in the treatment of Angina. They are contraindicated in heart failure but not ACS.
Reply With Quote Quick reply to this message
  #3  
Old 05-11-2010
USMLE Forums Veteran
 
Steps History: 1+CK+CS+3
Posts: 247
Threads: 61
Thanked 273 Times in 105 Posts
Reputation: 303
Default

Quote:
Originally Posted by S.Martin View Post
Calcium Channel Blockers are not contraindicated in the treatment of Angina. They are contraindicated in heart failure but not ACS.
In UW step 2 ck Q bank ........
Reply With Quote Quick reply to this message
  #4  
Old 05-12-2010
ath.pantelis's Avatar
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 187
Threads: 4
Thanked 368 Times in 121 Posts
Reputation: 398
Default

I'm not 100% sure, but I think that nifedipine (I suppose that by SSBs you mean dihydropyridines, not verapamil/diltizem) exerts its effect mainly on arteries (not the veins, as nitrates do). Thus, when there is already a compromise to a coronary branch due to ACS, adding an arterial dilator will evoke coronary steal phenomenon.
Reply With Quote Quick reply to this message
  #5  
Old 05-12-2010
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 3,317
Threads: 170
Thanked 4,879 Times in 1,808 Posts
Reputation: 4932
Info CCBs and Agnina

The main drugs used in angina are Nitrates and Beta blockers. The pharmacodynamic idea behind both of them is to decrease myocardial oxygen demand.

Calcium channel blockers are also used in angina for the same effect, however the spectrum of CCB differ, on one end you have Nifedipine which affects mainly blood vessels and therefore its action is more similar to nitrates and on the other end you have verapamil which affects mainly the heart muscle and therefore its action is more similar to beta blockers as far as treatment of angina is concerned.

CCBs are not contraindicated in angina. But they are less effective than nitrates or beta blockers. However, should you have a patient with heart failure then they are contraindicated as they have negative inotropic effect.

Remember that Hydralazine and Minoxidil (they are not CCBs) are absolutely contraindicated in angina because of the severe reflex tachycardia expected. Also remember that Pindolol and Acebutolol (beta blockers) are also contraindicated in angina because they are partial agonists.
Reply With Quote Quick reply to this message
The above post was thanked by:
ath.pantelis (05-12-2010), tomymajor (05-13-2010)
  #6  
Old 05-13-2010
USMLE Forums Scout
 
Steps History: Not yet
Posts: 34
Threads: 1
Thanked 62 Times in 15 Posts
Reputation: 72
Smile

The AC syndrome is ischemia of the heart muscle expressing itself
this ischemia is due to increased demands with less suuply so all drugs used play on this axis :
1) BB --> inhibit all cardiac properties --> saving of fuel --- > ttt the increaded demand
2)Nitrates ---> potent venodilator---> decrease the preload ---> decresed
demand + also it is coronary dilator-- > increased supply
3)ACEI : arteriodilator (without reflex tachycardia )---> decreased afterload --> decreased demand
4)CCB ---> act like BB by inhibition of all cardiac proprties and coronary dilator + ?
peripheral VD which differ according to subgroups e.g : short acting dihydropyridines e.g short acting nifedipine is potent peripheral VD-- > + of baroreceptors --> reflex Sypmathetic stimulation --> overcome the inhibition on heart--> reflex tachcardia ---> increased demand ---> preciptate and worsen ischemia
this can be avoided by use of additon of BB or using long actind nifedipine or other new generations in dihydropyridines or use other CCB groups
Reply With Quote Quick reply to this message
The above post was thanked by:
ath.pantelis (05-13-2010)
  #7  
Old 05-13-2010
USMLE Forums Scout
 
Steps History: Not yet
Posts: 34
Threads: 1
Thanked 62 Times in 15 Posts
Reputation: 72
Default

also note regarding HF
BB not totally containdicated it can be used up to NYHA III
Reply With Quote Quick reply to this message
  #8  
Old 05-13-2010
ath.pantelis's Avatar
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 187
Threads: 4
Thanked 368 Times in 121 Posts
Reputation: 398
Default

Quote:
Originally Posted by tomymajor View Post
2)Nitrates ---> potent venodilator---> decrease the preload ---> decresed
demand + also it is coronary dilator-- > increased supply
We have to mention, though, that the caronary dilatory effect of nitrates is exerted only on normal coronaries. If there is damage on the endothelium (like when there is a stable or unstable atheromatic plaque), this effect is rather negative, because the normal coronaries dilate and increase blood supply to their assigned myocardial area in the detriment of non-responding damaged coronaries.
Reply With Quote Quick reply to this message
The above post was thanked by:
tomymajor (05-13-2010)
  #9  
Old 05-13-2010
USMLE Forums Scout
 
Steps History: 1+CK+CS
Posts: 76
Threads: 22
Thanked 33 Times in 16 Posts
Reputation: 43
Default

Quote:
Originally Posted by ath.pantelis View Post
We have to mention, though, that the caronary dilatory effect of nitrates is exerted only on normal coronaries. If there is damage on the endothelium (like when there is a stable or unstable atheromatic plaque), this effect is rather negative, because the normal coronaries dilate and increase blood supply to their assigned myocardial area in the detriment of non-responding damaged coronaries.

coronary steal syndrome.........
Reply With Quote Quick reply to this message
The above post was thanked by:
tomymajor (05-13-2010)



Reply

Tags
Cardiology-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lung Resection Contraindication in Cancer? Viran23b USMLE Step 3 Forum 4 05-25-2011 09:40 PM
Contraindication to Smallpox Vaccine! Farqad USMLE Step 2 CK Forum 1 04-17-2010 02:24 PM
Contraindication for the use NSAID jackat1000 USMLE Step 1 Mnemonics 0 01-19-2010 04:36 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)