Hi guys, my name is Sanjay Guptaim, a consultant cardiologist in York. Today I wanted to talk to you about heart rhythm disturbances and in particular I wanted to try and explain what is it that makes a heart rhythm disturbance dangerous because by far and away the thing that scares everyone is that heart rhythm disturbances can be dangerous and the problem is compounded by the fact that there are so many different types of heart rhythm disturbances. They all have horrible names and very difficult names and there's a lot of jargon and no one really knows, you know, is this dangerous? Is, you know, you have PVC's, PAC's, HLTK, HL FLT, HLF, SVT, ventricular Tachycardia, non-sustain ventricular Tachycardia and wherever you look, you're like, oh this could be dangerous, this could be dangerous, this could be dangerous. So I thought I would try and explain it in a way that is easy to understand and try and break it down into basics to help you understand what the relevance of any heart rhythm disturbances and what is it that makes that heart rhythm disturbance dangerous. Okay, so the first thing to understand is that the only relevance of any heart rhythm disturbance, any heart rhythm disturbance, the thing that a heart rhythm disturbance indicates is that for the duration of that rhythm disturbance, the heart is not working as efficiently as it should. It's as simple as that, that's all it means. So the heart is a pump and the role of this pump is to pump oxygen-rich blood around to our vital organs and of course, if the heart becomes inefficient, then it will pump less blood around to our vital organs and of course, if there is a prolonged, if that is very inefficient and there is a prolonged duration of inefficiency, then you could cause damage. You could cause damage to our vital organs. You could code damage to our heart as well because our heart is one of those vital organs. So the first thing to understand is that that's all the relevance of any heart rhythm disturbances. The second thing then to say is, well, what is it? You know, that makes the heart, what is it about the heart rhythm disturbance? It tells you how inefficient that heart rhythm disturbances. And the truth is this, that the first thing to understand is that for a heart rhythm disturbance to be dangerous, to cause you damage, it has to be sustained. It has to go on for a certain duration of time because if it is very transient, it is not going to be enough to cause damage. Remember, what do we do with our lungs? Our lungs are responsible for getting oxygen in and they oxygenate our blood and the blood goes around. So if our lungs aren't working, for example, then you would have the same problem. You would get less oxygen in and you could cause damage. But we all know that you have to go a certain duration of time without oxygen to cause damage. Transient inefficiency, such as, for example, when we swim, we hold our breath. We don't do ourselves any damage by that. It has to go on for a prolonged period of time to cause damage. So the first thing to understand is that non-sustained rhythm disturbances, rhythm disturbances that don't go on for a prolonged period of time for more than 30 seconds, are not going to be dangerous. So if you have a topic, those by definition are not going to cause you any damage because they are so transient, you know, you're just being inefficient for that one beat and then it's followed by a normal beat. So any non-sustained heart rhythm disturbance is by definition not going to cause you any damage. And this also applies to things like NSVT, non-sustained ventricular attackic idea. It is non-sustained because it is non-sustained. The inefficiencies non-sustained and therefore will not cause you any damage. So the first thing is non-sustained rhythms do not cause us any damage. Sustained rhythms, sustained inefficiencies, more interesting, all right. And the duration of the sustained inefficiencies, very interesting. So if you have sustained inefficiency for an hour, that is not going to be as dangerous to us as, say, sustained inefficiency for three days. So that's the second thing to understand. The third thing to understand is the heart rate is important because the faster the heart rate during the rhythm disturbance, the more inefficient the heart. Why? Because the heart needs a certain amount of time to fill with blood. And if the heart is going very fast, it's not getting the time to fill with blood. And therefore less blood is coming out just because the heart is fast. Couple that with the inefficiency of a heart rhythm disturbance makes it more interesting. So someone who has, so let's say ventricular attackic idea at 110 beats per minute is not going to be in danger compared to someone who has ventricular attackic idea at 200 beats per minute because a, they have the inefficiency from their rhythm disturbance, be the fast heart rate compounds that inefficiency. The third thing that has an impact on our inefficiency is where the rhythm arises from. Okay. So atrial rhythms generally pump more blood out of the heart compared to ventricular rhythms. So that is why atrial tachycardia is not as inefficient and is so much better tolerated than ventricular tachycardia because by very nature, if it's just a ventricle that's pumping the blood out, you're only getting the ventricular bit pushing the blood out. The ventricle is doing the work. If you have it atrial rhythm, the atrial is pushing blood into the ventricle and helping the ventricle push the blood out. So your ventricle is filling with more blood because the atrial is pumping into the ventricle and that's pushing the blood out. So you're getting more blood out. So that is why atrial rhythms are less inefficient compared to ventricular rhythms. And finally, the most important thing is do you have a heart which is already inefficient to start off with before you develop the rhythm disturbance? So if you have a damaged heart, if you have a heart that is only working at 20%, you then add in a sustained heart rhythm disturbance, which goes on for several hours, which is ventricular, which is really fast. There we're talking about a dangerous rhythm. But otherwise, if you have a non-sustain rhythm, it's not dangerous. If you have a rhythm which is atrial, as opposed to ventricular, it's not going to be as dangerous. If you have a rhythm which goes slow, it's not going at 130 beats per minute, that's not going to be as dangerous as a rhythm that is going to get 200 beats per minute. And finally, if you have a structurally normal heart, then because the heart is strong, whatever inefficiency is happening because of the rhythm disturbance, at least the heart is a strong structure and therefore does pump some blood out. Yes, it won't pump out as much because of the inefficiency from the rhythm, but it's still able to pump something out. If the heart is already weak and on top of that you add in the inefficiency, then the heart is going to pump out a lot less and that inefficiency is dangerous. So when people contact me and say, oh, I've got to ectopics, are they dangerous? Of course they're not dangerous. I have non-sustain VT. Is that dangerous? No, it's not dangerous at all because non-sustain VT is non-sustain. The inefficiency is not sustained. It is not going to do us any harm. Sustained rhythms, which are ventricular, which are very fast, which are on the background of an already damaged heart, those are the rhythms that are dangerous. So I hope this helps you understand what makes a heart rhythm dangerous and it makes you realize that actually you have to have a lot of things, a lot of bad things for a heart rhythm disturbance to be dangerous as opposed to just the odd ectopic here or a little run of non-sustain VT or something like that. So I hope this was helpful. I would love to hear what you thought of this video and I hope this makes sense and if I could do things better please let me know. Other than that I'm really grateful to it for everything you do. I'm sorry I haven't put a video out for a while but I will do another one and I think my next one is going to be on Wolf Parkinson White Syndrome. So thank you so much and all the best. Take care.