Class II- Beta Blocker= Anti-arrhythmic drug
Okay everybody assalamu alaikum and today we are going to talk about class two of anti-arithmetic drugs class two is beta blockers and i’m sure you all would be like oh we know about it isn’t it because we have already uh discussed drugs that are used to treat congestive heart failure and other conditions where we discuss pedia blockers in deep detail so i will
Uh talk about it where it will make some difference okay i’m not going to dig deep into it all right so again current action potential i want you all to remember this uh first step is depolarization then it’s phase one phase two phase three and then there’s phase four now this is class two right and here if you see here so you see here is making this difference
All right so what happens here is wait a minute let me get the point okay so what happens here is remember if you go back so this is phase four okay wait i’ve got a message oh okay rapida grab your bitter thank you so much robin please remind me after the class okay i want to post this question actually okay thank you so much rabia okay i’ll talk about it don’t
Worry okay so you look see uh this is phase four all right and when if you if you look at the graph where i try to compile all of the drugs actions together so you see here this is class two effect right so what it’s doing is you see it is uh you know affecting phase four all right so now how it’s going to effect let’s read about it so you see class two are
Beta receptor ergonomic and agonists including proper enol which act by reducing sympathetic stimulation what they’re saying i’m sure you all know about it they inhibit phase 4 depolarization depress automaticity prolong av conduction and decrease heart rate okay what do they mean because you see i tell you what here in just two lines they have literally used so
Many terminologies which are important for this class of drug okay and literally in the exam you’re asked about it that which class of drug decreases automaticity prolonged av and you know stuff like that okay so you see uh first of all we have already talked about that what is space for so they use they inhibit space for depolarization so when we talk about
Phase four depolarization okay so you see here so it means that they are affecting this this is specific part of the cardiac conduction all right and whenever we talk about depolarization what does depolarization mean depolarization means that positivity is getting inside the cell okay whenever i talk about repolarization it means that positive eyeliner is
Going out of the cell and negativity is being increased within the cell all right so when i say when i say that it inhibits phase 4 depolarization it means that it will inhibit positivity to get inside okay and that’s how the effect will be produced so it will depress automatically prolong depress automatically what is automaticity automaticity is this that uh
You know heart does not need a specific set of instruction from us uh in order to get it in the beating state right it does read on its own right so whenever we say depress automatically it means that it is sending less electrical signals okay and which is why the av conduction is prolonged and of course when it’s being prolonged so ultimately heart will beat
Less right except for ages that have sympathetic activity as well and contractuality so the major drugs as i’m sure you all already know the names of these drugs i’m sure these are not a new set of drugs for you so this is propranolol and then we have a small so you see these are two important drugs so when we talk about propane oil so it is a non-selective beta
Adrenoreceptor antagonist all right when i say non-selective it means that it will go and it will start hitting the period receptors wherever they are this either their meter one beta two or whatever right okay but then we have s butylon and esmalon which are selective and they are selectively antagonizing beta one adrenal receptors right okay so that’s how these
Two drugs these three drugs actually control or treat the ventricular arrhythmias isma is ultra short acting is administered by infusion and it is used to titrate block during surgery now what is this titrate titrate means that they keep on giving and they keep on monitoring and how much of the drug is required and then the dosing the is being adjusted then
We have propanol metoprolol nadulon and timulon so these are frequently used to prevent recurrent modifier uh mariocardial impact myocardial infarction in function for myocardial infarction what is recurrent weaker means that it is happening again all right okay so therapeutic uses class two drugs are used to treat um attacking arrhythmias caused by increased
Sympathetic activity so yes they are blocking the sympathetic nervous system they are also used for a variety of other arrhythmias including atrial flutter and atrial fibrillation these drugs prevent reflex tachycardia produced by vasodilating agents they are sometimes used for digitalis toxicity so adverse effects are uh arteriolar basal constriction and
Bronchospasm okay because of the compensation mechanism then we have bradycardia heart block and myocardial depression may occur as we have already talked that it will depress the heart rate atropine or isoproterenol may be used to elevate pericardium that is it for the class two of the anterior argument
Transcribed from video
Class II- Beta Blocker= Anti-arrhythmic drug By Fiz Teach
