Left Bundle Branch Block

raunch flock now several of you have seen my video on right bundle branch block and then written to me and said well are you gonna do one on left bundle branch block so I thought I'd do this today so here goes the first thing to say is left bundle branch block refers to abnormal electrics of the heart okay not abnormal plumbing so a lot of people hear the word block they hear left bundle branch block they hear the word block and they assume that this is a reference to heart artery blockages and this is an incorrect assumption left bundle branch block is an electrical issue not in are not a heart artery issue so it doesn't automatically mean that your heart arteries are blocked or anything like this this is an electrical problem which is separate to the blood vessels the second thing to say is left bundle branch block is a pattern on an ECG okay you do not go to your doctor and say I think I have left on the branch block and neither can a doctor look at you and say oh I think you've got left bundle branch look they can't do that the only way someone can diagnose left bundle branch log is when it is seen on an ECG a tracing of the heart rhythm okay left bundle branch block does not cause any symptoms but it is useful to pick left bundle branch block up because it can give you an insight into what's going on in the heart and it may prompt further investigation into the heart let me talk you through the electrics of the heart so that you understand it a little bit more all right now in the normal person the electricity is generated in a part of the heart here we go my trusted model up here just in the near the atria near the top two chambers and that area of the heart is called the sinoatrial node we also call it the natural pacemaker of the heart so everyone when they're born they have an area of the heart which releases the electricity the electrical impulse is generated and then the electrical impulse has to travel down some complex wiring here so the there's a wiring system here and the electrical impulse comes down and now the wiring separates into two okay this is the right heart here so the wire goes to the right heart through and the wire going to the right heart is called the right bundle the wiring going to the left heart is called the left bundle all right and so the electrical impulse will come down and then divide and go to the left bundle and the right bundle and as it goes down both together both ventricles both chambers contract at the same time because they're getting the electricity going down at the same time now if there is a problem with the wiring going to the right heart okay with the right bundle that's called right bundle branch block if there is a problem with the wiring going to the left heart such that the impulses are not able to travel to the left heart then that is called left bundle branch block okay now usually as I say both sides of the heart received the electrical impulses at the same time and this causes both sides of the heart to contract simultaneously however if you have bundle branch block then the area where there's the block so if you've got a block in this wiring that means that the impulse will go down this preferentially it will go down here they won't go down here and therefore this part of the heart the left heart here in the cases of right bundle branch block for example the left heart will contract earlier than the than the right heart if you have left bundle branch block then the right heart will get the impulses first because the impulses can't go down the left bundle here and the right heart will contract before the left heart now you may think oh well if the impulse is aren't going down there then how can the left heart contract because there's no electricity to make the left article drink and you would be right in thinking that however all heart muscle can transmit impulses so you will still get impulses but they just won't go down the left bundle they'll come from and because all muscle can transmit electricity the electricity will come from here and then through the muscle activate the left heart so the left heart will still contract it will just contract later than the right heart and because it's contracting slightly later it's not going to cause as effective a contraction because there's now dis synchrony there is a lack of synchrony of both ventricles contracting at the same time so that when you get left bundle branch block the heart does not contract as because as effectively as if you're both your bundles are working fine but it when I say effectively I'm saying it's not working to maximum efficiency and there's a slight drop but not a huge drop when you have left bundle branch block okay now then have a look at sacral difference between the right bundle here and the left bundle the right bundle goes through this very thin layer of muscle here okay so any little insult to this can affect the right bundle and therefore right bundle branch block as much commoner and generally not considered a major abnormal finding however left the left bundle goes through this very thick layer of muscle here okay and if you see left bundle branch block then that usually signifies an abnormality because and the left bundle is embedded deep into this muscular layer and it's actually generally very difficult for the left bundle to get affected unless there's something significant going on now left bundle branch block is always abnormal okay and therefore should always prompt investigation note I said abnormal not necessarily dangerous left bundle branch block is not necessarily dangerous it's abnormal it requires further investigation into the heart but if you have had the investigation and the heart is bound to be healthy and some people do have left bundle branch block with a completely healthy normal heart on investigation those people actually do find they they have no adverse outcome in the long run compared to someone who doesn't have left bundle branch block and but if you see left bundle branch block then it is vitally important that someone investigates you your doctor in vets this sends you to a cardiologist to be investigated just so that any underlying cause of the left bundle branch block can be excluded or treated okay now what kind of things cause left bundle branch block well the first thing to say is just simply age you know the the older you get the more likely you're going to have wear and tear of the electricity so you can get it with age number two and when I mean age I don't mean 40 I mean 8090 you know something like that advanced age can do it and the second thing is heart disease so if you have anything that is affecting the left ventricle say you've had a heart attack which was scar over here this part of the heart muscle has died obviously the left bundle goes through this muscle so if this muscle is died there's no electricity that can go through so that could cause a left bundle branch block also if you have abnormal heart muscle so if you were born with abnormal heart muscle and this is cardiomyopathy for example that bull and inherited cardiomyopathy then maybe the muscles will not allow transmission of the impulses down the left bundle and that could cause left bundle branch block some infections lines disease for example myocarditis viral infections they can also cause left bundle branch block and also another cause for left on branch block is long-standing high blood pressure because the heart is working much harder and because it's been under strain and the muscle is working much harder in the muscle is strength that can sometimes affect the contraction and that can also grab sorry can can affect the electrics and that can also cause left bundle branch more okay so what is the significance of left bundle branch block the first thing is that how do you pick it up when you look at the ECG usually when you look at the heart you had this spike that you see okay and if you measure the width of that spike that width of that spike should not be more than 120 milliseconds and that equates to three small squares on the ECG now I did try and draw a left bundle branch block for you but I'm silly and I didn't realize that the image gets reversed when I share it so it'll all look reversed so rather than share it I'll just try and explain it to you so when you have a bundle branch block the spike the the duration of the spike the width of the spike gets bigger than three small squares or greater than 120 milliseconds and that's when you start thinking of bundle branch block so that's how you pick it up on the ECG how do you investigate it well obviously you can only diagnose it on an ECG so you have to have the ECG but after that if you have left bundle branch block you should always be sent for an echocardiogram a heart scan to look at the heart muscle to make sure that you don't have any scarring of this area that you mean that to make sure that you haven't had a heart attack without knowing about it to make sure that you haven't been born with a cardiomyopathy that you didn't know about to make sure that the heart isn't weak but if your echocardiogram is normal if your heart scan doesn't show those things and you are otherwise completely fit in well then nothing else needs to be done alright um and in those people who have had an echocardiogram and the echocardiogram is normal you know those people tend to do well there's no real there's no real bearing of the left bundle branch block on their overall life span or quality of life of course if the left bundle branch block is an indicator of underlying heart disease then your prognosis depends on the underlying heart disease and what is the significance what is the important bits about left bundle branch block one you know your heart is the one of the electrical pathways has been damaged so the heart is relying on the right bundle the electricity comes from the right bundle and if the right bundle gets nicked or affected then you have something called complete heart block where the electricity isn't able to get through from the top that doesn't mean you die what it means is that the heart will start beating very slowly because it'll rely on other parts of the heart muscle to start firing and generating their own electricity so the heart can slow down and you can develop complete heart block and if that happens often patients do need pacemakers putting in artificial pacemaker which will allow and the pacemakers put in so that it actually generates the impulses down here so you're not reliant on these bundles the second thing to say with left bundle branch block is that when you have left bundle branch block it renders the ECG unreadable meaning that you've got the left bundle branch block pattern you can't look any further beyond that so often if you come in for example with chest pain into the hospital because you've had a bit of gastritis and if you've got you know GERD or something like that and if you've got left bundle branch block most people will assume that you've had damage to your heart and that's cause the left bundle branch look and because they can't you know they can't interpret the ECG any further all they can see is that the ECG is abnormal and you've got chest pain so they'll automatically make the assumption that your pain is coming from your heart and therefore if you have left bundle branch block it's is very important to mention it to your doctor straight away if that happens to say actually this is pre-existing this is not new even though it's pre-existing what it does mean is the doctors just have to be a little bit more careful because they don't know what the ECG means so that that's one thing out of their diagnostic armamentarium they can't look at the ECG anymore because the ECGs got left bundle branch work they can't look at it to say well something new is happening and therefore they have to have a much higher index of suspicion for other things they need to keep you in under SLUSA scrutiny they need to rely on blood tests etc they can't just rely on the ECG because ECG is abnormal anyway the final thing I'd like to say about left bundle branch block it if you have a weak heart and you develop left bundle branch block because now what happens is you develop this synchrony one part of the heart is beating faster or quicker earlier than the other part of the heart the left bundle branch block can cause the heart to be even weaker and therefore in those people who have an already weak heart who then developed left bundle branch block sometimes they can undergo a special kind of pacemaker older biventricular pacemaker where you can actually put a wire and do both sides of the heart and try and synchronize in them and make them contract at the same time and because you can do that that then improves the function about because you've taken away the effects of the delayed de synchrony caused by left bundle branch block so that's the significance of left bundle branch block I hope you found this useful if you have any questions please don't hesitate join me on my Facebook page I've now started doing a live Facebook question-and-answer session every Tuesday so if you have any questions come over to join me on the Facebook page feel free join me on a Tuesday evening to ask me any questions you want my Facebook page is your cardiology one if you type your cardiology one you'll find me other than that thank you so much for listening thank you for watching thank you for your great comments if you want to speak to me you can do so by contacting me through my website www.rockymountainatvmc.com

Channel: York Cardiology

Views: 30,918

Rating: 4.9480519 out of 5

Keywords: iMovie, LBBB left bundle branch block, LBBB, heart block, pacemakers, anxiety, palpitations, heart failure, yorkcardiology, sanjay gupta

Id: eS87BBQQAkI

Length: 15min 14sec (914 seconds)

Published: Wed May 10 2017