A moment of reflection

The sky is a beautiful shade of blue. Tiny clouds, wisps of water vapour drift slowly into view, then disperse as the sun’s rays warm them. Bird song rings out, the calls and responses of feeding pairs feasting filling the air.

It is 7 a.m. and I am sitting, bleary-eyed, in a camping chair in my garden, my cold-weather down clothing insulating me from the morning chill. A mug of coffee adorns the garden wall to my left, to my right inquisitive birds are feeding on the lawn, their beaks pecking at, to me, invisible prey. The scene is one of calm serenity, of nature at-one with itself.

Of course, the world does not share the sereneness of my environment, for outside the calm and tranquillity of my early morning scene lays the mystery and panic of the pandemic which has, as it seemed, from nowhere, engulfed us. The pandemic that has caused misery for millions, has caused turmoil in our lives, has redefined normality, has hastened the demise of tens of thousands of people.

And, although I sit in my reverie, imbibing my coffee, soaking up the early morning tranquillity, I am not immune to the world outside, not isolated from it, not dismissive of it. Its effects and ubiquity have already visited me, for I have felt the embrace of SARS-Covid, of its warm and painful surprises, its valiant attempts to overwhelm my defences, to add me to the list who have succumbed.

But it precisely because I have suffered, and fought, and triumphed that I am here in the dawn bliss. Covid’s attack, now shrugged off, has led to a resurgence of a lust for life, of a yearning to do more, to grab and embrace off of life’s opportunities.

The sky has never been a more beautiful shade of blue, the birds never so dainty and appealing and joyful to watch, the very act of being alive never having been more intense. My family’s history, my rendezvous with ventricular-fibrillation, my skirmish then full-scale assault with Covid has awakened something in me, and if my sojourn with cardiology had not awakened me, then my isolation and Covid’s embrace certainly has.

If there is a lesson in this, of a lesson for me, for us, for anyone, it is that being alive is precious, each day a bonus, that each moment must be grabbed and held close.

And as I sit here in the tranquillity and romance of the start of my day I am content to just be alive and to enjoy the blueness of the sky.

Image by Sariwes from Pixabay

Question time #1 with Dr Tom Keeble

In episode #40, in the second part of his conversation with Paul talks with LACA regular consultant cardiologist Dr Tom Keeble.

Dr Keeble answers cardiology questions that have been put to him by members of Sudden Cardiac Arrest UK. These include the subjects of beta-blockers, electrolytes such as potassium and magnesium, atherosclerosis (furring of the arteries) and future risk, anti-platelet therapy, super-asperin, ectopics, ICD’s (implant healing and leads).

Available to listen on the link below or Spotify, Apple , Google, YouTube and your favourite podcast player.

#040 Question Time #1 with Dr Tom Keeble

Paul Swindell: Hello and welcome to another episode of the Life After Cardiac Arrest podcast with me, your host, Paul Swindell. I'm joined today by Dr Tom Keeble, who's here to answer some of your questions that we've had in the group.

So welcome, Tom, and welcome on this beautiful sunny morning.

Dr Tom Keeble: Yeah,

Good morning.

Paul Swindell: We're going to jump straight in because we've already been chatting about Covid 19 but we're going to go onto subjects that aren't related to that cause we tackled most of those questions in the previous episode. So, the first question is, why are beta blockers prescribed after a sudden cardiac arrest that was triggered by an exercise induced oxygen demand ischemia. If the original cause has been rectified by surgery and they had a bypass and they've got ongoing management with statins, diet and exercise. So, it's always the, the beta blocker question

Dr Tom Keeble: So, look. I, a very medically asked question.

So, the bottom line is, beta blockers are a good drug. A lot of patients don't like beta blockers if they have side effects. And I can understand, you know, if you feel tired, if you have bad dreams, if you have, any of the other side effects of dizziness or anything else that you don't like, but the bottom line is, is that had I had a cardiac arrest, whether it's a VF or a VT, a an arrhythmic arrest that needed defibrillation, the best drug on the planet to take is essentially a beta blocker, and the beta blocker is excellent for a variety of reasons. First of all, from the question, the way in which the question was worded,

Number one, it reduces your hearts oxygen demand all of the time because it lowers the heart rate.

Number two, it makes your heart more efficient.

Number three, lowers your blood pressure a bit, which in most patients with cardiovascular disease is what is required.

It also makes the heart pump better. It reduces arrhythmia's, and we know from long term studies, in randomized studies, it prevents cardiovascular death.

So, if you're a patient who's already had essentially an aborted cardiac death from having a cardiac arrest and being resuscitated, it's kind of hard from a medical standpoint, from all of the reasons that I've just stated. Why you wouldn't want to be on a beta blocker.

For me, that would be the tablet that if I wasn't on, I'd be asking, why am I not on it?

Now, as I say, we understand many people may be allergic, people might have terrible asthma and can't take it. That's very rare. and of course. If the side effects are so overwhelming that they outweigh any benefits to you, then of course you wouldn't want to take them.

But most patients tolerate beta blockers well. And I think the other thing is that a lot of the side effects of beta blockers that people would describe are tiredness. Now we know that your group of patients post cardiac arrest and brain injured patients have a huge amount of tiredness and fatigue anyways, it's the number ep symptom that cardiac arrest patients describe, so to put it down to your beta blocker is probably unfair.

So, I think we have to take every patient on a case to case basis. Beta blockers are not good for everybody. That's not what I'm saying, but in the vast majority of cardiovascular induced, and what I mean by that is furred arteries and heart attack induced cardiac arrests. Beta blockers are a good drug and should at least be trialed and should at least be given time to have a chance of getting used to them. But if the side effects are completely untoward and that the patient can not tolerate them, then of course in line with your physician, your cardiologist, they should be considered for a, a different tablet.

Paul Swindell: I mean, there are, there are many different types of beta blocker aren't there?

Dr Tom Keeble: That's true. To be fair, over the last five years, most people have come down to use pretty much one or two, and the most commonly used one, which has a very safe and a good side effect profile is Bisoprolol and the reason why that's good, it's a cardio specific beta blocker, which has particular benefits in heart failure patients, which again, if you've had a cardiac arrest and your heart pump is not completely normal, you will benefit from these cardiac specific ones.

And the ones that we use in those include Bisoprolol, Carvedilol, and Metoprolol. But by far the commonest used one is Bisoprolol. It's generally used once a day you can use it twice a day. I do sometimes, but it's generally used once a day and it's an incredibly good drug.

Paul Swindell: And following on from that, someone says they've got, DCM dilated cardiomyopathy and an SICD, and they've had a couple of, appropriate VF shocks and they've had a couple of, episodes of VF, which have been self-corrected, and they say, is there a link between taking my Bisoprolol at 8pm and my Ramipril and Eplerenone at 10-11 o'clock causing my VF? My heart rate usually sits between 40 to 60 BPM when asleep, but sometimes goes as low as the 30s.

Dr Tom Keeble: Sure. Well, I think it would be very interesting to know just in this personal case, when the cardiac arrests have occurred and the defibrillator has had to do its job, and I think what we do know with any drug is that even if you have a controlled release drug, you do not maintain exactly the same drug concentration over a 24 hour period.

And that we know that there's a sort of bell-shaped curve where you of course, absorb it. It has it sort of peak effect. And then even with slow release medicines, the concentration in your bloodstream, then weans off over the next few hours, then waiting for the next dose the next day, 24 hours later.

And I suppose what this draws into, into close point is that. We need to take our drugs regularly at the same time, at the same, on the same time every day, so that we can give our body the best chance of having a steady state. So, with regards to, to VF and VT. Ramipril and Eplerenone are both drugs to try and improve the heart function and keep the potassium normal.

So, I don't think it's likely that that are sort of a daily variation in their dose would have an effect on whether you would have a VF or VT. But of course, a beta blocker, as we talked about slightly earlier. It's a very powerful protective anti, arrhythmic medicine that if you either missed your dose or maybe you were at a low point in your dose curve and you did some exercise or some stress or something, then that could potentially give rise to it.

If people have a particular arrhythmia at a particular time, let's say at seven o'clock in the morning, the low point of your beta blocker dose because you take it at eight o'clock in the morning then sometimes we space out the beta blocker and give it half in the morning and half at night so that you have a slightly.

Smoother and sort of better profile throughout the 24 hour period. Of course. The other thing is you can consider other anti arrhythmic drugs under the watchful eye of your cardiologist or electrophysiology doctor to ensure you're on the best possible medicines to limit your exposure and limit what your subcutaneous ICD has to do.

Because. At the end of the day, we want the ICD, whether it's subcutaneous or a normal ICD to be your insurance policy, and we don't really want to use, if at all possible, we'd much rather we can control things. With medicines and then the ICD is there just to get you out of jail. If an arrhythmia occurs.

Paul Swindell: you touched on potassium there, someone, so on the third of the question, it's not on potassium. It's talking about magnesium levels and the hearing that magnesium levels are critical to a heart functioning correctly. And it's also read that. Magnesium levels are rarely tested, and they wonder why this is, especially in the cases that are idiopathic.

Dr Tom Keeble: Yeah. Good question. So, I think if any patient comes to the hospital with either cardiac arrest or arrhythmia that has hospitalized someone, that we always measure magnesium. So, magnesium, obviously is in our diet and that's where we predominantly get it from a lot of people are slightly magnesium deficient.

We see that in many patients who come through the door. And the good thing is it's very, very easy to remedy either at home with supplements or what we do in the hospital is we give a magnesium infusion, which we can get the magnesium to normal levels within about two hours. And so that can often help prevent any further arrhythmias.

The other important thing about magnesium is that it also helps reabsorb potassium. So, if you are really low in magnesium, you will often be really low in potassium too, depending on what other drugs you're on and what your dietary intake is like. And so that. Can also cause problems. So often we need to get the magnesium levels back to a normal state, which will then in time allow the potassium levels to come back to a normal level.

And the bottom line is, is that the body is very clever at controlling all of its salt levels and any significant deviation of a particular salt level, be it potassium, bit sodium, be it magnesium bit calcium can have detrimental effects upon your heart rhythm. but no, we definitely don't, monitor magnesium.

And if you like asymptomatic patients in the community that we, we, we've never done that. But if you have persistent arrhythmias, either at home or in hospital, then we would generally, measure it and replace it as we see fit.

Paul Swindell: the question asked about the fact that they are rarely tested it.

I did read somewhere that it's actually hard to do a, an easy test without being invasive, I. E. taking a blood sample or even. Is it in the bone marrow? Is that correct?

Dr Tom Keeble: No. So, it makes, magnesium is definitely from blood serum. You can do it. There is a point of care test. We have it in our catheter lab where you can take a finger prick sample and put it onto, yeah.

Into this point of care machine. And it will give you, you the magnesium, as a point of care. So, it is quite easily measured. You can do it with a, a, say a finger prick or more generally you would do it from a, a blood sample.

Paul Swindell: Do you know the home test kits? Do you know,

Dr Tom Keeble: I wouldn't bother with that to be perfectly Frank.

I think that, you know, I think again, you got to go back to simple things. If you're well and you have a balanced diet, the chances of you having a low magnesium and low potassium are, are low.

Does that make sense?

Paul Swindell: Okay. Yep.

Paul Swindell: and this goes back to the original question. It was sort of a

Paul Swindell: How does having a sudden cardiac arrest due to buildup of cholesterol, increase the risk of a future event if that is being managed.

Dr Tom Keeble: So, if you have a cardiac arrest secondary to a furring up of the arteries or atherosclerosis is the sort of terminology, then usually that is in the setting of a heart attack where you get a sudden occlusion of blood supply to your heart muscle and your heart muscle doesn't like it and goes into this fibrillating state where it sort of wobbles and then you pass out and have your cardiac arrest in the treatment, of course, is CPR recognition and defibrillation, hopefully in the community or if not in the hospital when the paramedics arrive.

What you have to remember with atherosclerosis or furring is it's a continuous process. The risk factors need to be controlled to prevent this from happening long term. So if you get a bypass or a stent, all that really does is sort out the acute problem, gets the blood supply fixed, quickly, but of course if you still have high blood pressure, high cholesterol, overweight, diabetes, and these are all badly controlled, then the furring�s will just come back within a year, six months, two years.

And so, once you've had these events caused by furring, it is absolutely vital that we focus on all of the risk factors to minimize the risks of that happening in the future again. And so really careful attention to cholesterol with statins, really careful attention of blood pressure with pills, really a careful attention of diabetes and weight loss and exercise regimes and all of these things together prevent you from having further events.

The stent is not the cure. All the stent or the bypass does is make the blood supply good at that moment in time. It does nothing to prevent the future events, which of course is the most important thing.

Paul Swindell: Okay. And it's sort of as, as you sort of touched on life lifestyle and diet and things like that, I guess a more and more important, obviously the fewer tablets you can be on, the better.

I would say, personally,

Dr Tom Keeble: I think that's wrong and it's not because I'm a prescribing doctor. I think the bottom line is you need the tablets that you need and everybody will be different. Patient A who's had a idiopathic cardiac arrest and has a defibrillator, may need no tablets or may just have a beta blocker.

It depends completely on the cause.

Depends completely on the risk of other things happening.

Depends completely on the risk factors if there's a coronary patient, but if you've got a patient who has a pump, which is not great, has a high cholesterol, has diabetes. You would, you just need to control all the risk factors.

And I don't mind if that's with tablets or if that's with lifestyle. So let me take diabetes for, for example, if you are a 60 year old male and you have a cardiac arrest because of a heart attack and you are overweight, let's say you're 16 stone and you have type two diabetes, there's really good evidence out there that if you slim down with exercise over time and in a sustainable way.

So say for instance, 12 stone, which may be is the right weight for that human being, then you're type two diabetes is highly likely to go away, I. E. your sugars would go back to a completely normal level because the fat, would you, it gives you insulin resistance and therefore you get type two diabetes.

So, we have to look at evidence too. So, every tablet that a patient is on post heart attack is not just to make us feel better. It's to reduce the risk of cardiovascular death, heart attack and stroke. And for each tablet that patients are on, be that aspirin, be that Ticagrelor, be that an ACE inhibitor, be that a beta blocker.

Be that a statin, be that Eplerenone the list is getting bigger and bigger and bigger. All of them in 20,000 people, randomized controlled trials have shown benefit to prevent heart attack, stroke, and death. And of course, if you are interested in not having a heart attack, stroke, or death again, then we would want to consider taking these tablets unless there's a very good reason not to.

But, I'm very comfortable with people, not taking, tablets. If they can adjust their risk factors with lifestyle modification, which is possible, certainly with diabetes and can be possible with cholesterol, but at the same time, you will not get your cholesterol level to the levels that you really want to, which is less than four.

And not only that, many of these medicines have unexplained benefits. The mechanisms of which we don't understand but are likely to be reduced inflammatory processes, which we know are really important in heart attacks. So my take home message to use, I don't have a disagreement with saying you should be on the minimum number of tablets that you can, you know, that you have to have.

But bear in mind, you need to control each of your risk factors. Well with evidence based medicine. But I think the best one to say, yet, you probably don't need a tablet if you can do it yourself is diabetes. And if you can lose whatever weight is required to get you to your optimum weight, then I think that is a fantastic healthcare way of avoiding diabetes drugs.

But at the same time, you will reduce your cardiovascular risk.

Paul Swindell: Absolutely. No, I wasn't saying that the patient shouldn't be taking tablets or any, evidence based medicines. I'm just saying some people sometimes need to address some easy things like their lifestyle sometimes first

Dr Tom Keeble: it's a part of the equation and you're right. Mental health, physical health and exercise are really important. Joint effort component. I think the other thing is I think we are very lucky in most of the UK that we have a pretty superb, cardiac rehab service certainly in, in Essex we have a brilliant cardiac rehab service and they do a lot of the education surrounding tablets.

And why you're taking this, because. If you find, if patients don't understand why they're taking them, then they often won't take them. Why? Why would you take something that you don't fully understand why you're taking it? But if you're very clear as to what you're taking, why you're taking and what the consequences are of not taking them and what they're trying to achieve, and in collaboration with lifestyle changes, then I think you're much more likely to be successful.

Paul Swindell: Okay. this next question is about someone who's had a auto immune diseases for many, many years and apparently they can lead to heart attacks and cardiac arrest, but without, necessarily any previous risk factors like high blood pressure or high cholesterol

Is there any evidence that supports carrying on the antiplatelet therapy for longer than a year protects the stents, if any, and the heart in general?

So yes, there is emerging evidence, and it's only one tablet. A drug called Ticagrelor. Ticagrelor is super aspirin. So, if you have a stent currently at our cardiac center, you will go home on aspirin and super aspirin, Ticagrelor which is a twice daily preparation at 90 milligrams, generally. Now the, there may be variations, there are two other drugs that we can also use. So. Please don't worry if you're on a different one. This drug was trialed in about 18,000 patients that at the end of that one year, they randomized patients to have a lower dose of Ticagrelor, versus just having aspirin alone.

So, aspirin alone versus a lower dose of super aspirin with the aspirin. And what they wanted to understand is, the problem with the super aspirin drugs that we give with stenting is that they inevitably, when you're trying to prevent clots forming, you inevitably have a downside of potential increased bleeding risk.

And many of your patients who have got these medicines and got stents will describe very much that when they shave, they have bleeding, when they knock themselves in the garden, they have big bruises. Their skin has bruises all of the time on it, and that is the nature of this beast. And so, you can imagine having a super aspirin for longer may be great for your stent, but it may be very bad for bleeding.

You could have a bleed into your tummy, you could have bleeding elsewhere, that requires medical attention. So, this trial was really important to try and understand if. The, the benefits of not running into problems with your stent and your cardiovascular system outweighed any bleeding risk. And the answer was yes.

And so absolutely in low bleeding risk patients. And what I mean by that is genuinely younger patients. You have maybe lots of disease in lots of vessels and potentially diabetes, and there were very specific criteria are likely to benefit from aspirin with a lower dose of super aspirin out to another further three years.

And that certainly what we're currently practicing at the cardiac centre and most places in the UK, because. We follow the same data. but as I said to you, if you are home and you're not on it for longer, then please do not worry. It's because your physician has decided that it's not likely that you're going to benefit.

And the decision is that there is, there were a number of criteria that we need to weigh up, but the predominant one is bleeding risk, and so if you're a high bleeding, which we would never entertain it. In fact, we want to have a short, aspirin and super aspirin, amount of, of time. So it's. The answer is yes, that some people will benefit, but it's on a case by case basis.

There is some evidence for it in certain patient groups. and your cardiologist will support that decision making.

Okay. and this person has got slightly complicated history, although it's actually quite reassuring because he had his, first cardiac arrest back in the, in the nineties or the early part of the 90s, and he had, an IC always had several ICDs, which have saved him.

And back in 2003, he had a, an MV, What's that mitral valve, implanted or, fixed. And he hasn't had a, an incident since then. So, they probably think that that was the original cause of his cardiac arrest. And the fact that he hasn't had one for 17 years now is the possibility of any further arrest now significantly reduced.

Do you think.

Dr Tom Keeble: I think it's incredibly challenging to know. I think the good thing is you rightly say is that this chaps not had one for 17 years. And so that's fantastic news, isn't it? Do you know what I mean, I think none of us have a crystal ball, it's unusual. I mean, there are some associations with mitral valve disease, which can cause cardiac arrest, and arrhythmia's and clearly that has been fixed.

You don't know. Also, at the time of that procedure may be a number of his medicines were also optimized, which may also support his, arrhythmic burden and the fact that he won't have any fear of the trouble with that. So, you know, I think that I, yeah, I, and on a case by case basis, it can be challenging to untangle everything, but it sounds like he's had a great operation to fix his valve and that these tablets are good and he's in good shape.

And I think, yeah, I think to try and untangle it any more than that can be a challenge.

Paul Swindell: Okay.

I've got a couple of questions which are related around ectopic beats, and someone asks, what are the symptoms of ectopic beats and are they anything to be worried about?

Dr Tom Keeble: Every human being on this planet has ectopics. Okay. And what an ectopic beat is, is that the top part of the heart, the atrium beats first, pumps blood into the ventricle, and then the ventricle beats and pumps blood around the body.

And what happens with a ectopic is that the ectopic doesn't have usually, or it can have an atrial beat, but it's usually a ventric ectopic where just an extra beat from the bottom part of the heart comes in. And so often what happens is, is that people feel either an extra beat or a missed beat, and it's incredibly common and people will often have it at times of stress.

People will have more often after they've had tea or coffee. Exercise generally gets rid of ectopic beans. And so look upon it. Topic beats as an extra beat, either from the top or the bottom of your heart. They are generally benign and nothing to worry about.

And what I tend to do in clinic when I see patients that describe these extra beats is do a monitoring usually for 24 hours to understand how many extra beats they have in a 24 hour period. Cause that's important.

If you're having thousands, I. E. you know, that's a lot in a 24 hour period. then we would want to consider trying to use medicine to reduce that amount of ectopics because we know that it can make the heart quite inefficient. But the vast majority of patients do not have that many.

And we'll have, you know, a hundred in a 24 hour period or 30 or so, and actually that is completely normal and is of no concern and we would do nothing about that. We would not advise medications for that. It's only if you have. Literally hundreds or thousands and are bothered by the symptoms. And once again, a beta blocker is an excellent choice of drug to suppress these extra beats, but we would only do that if they are very often and troubling the patient.

Paul Swindell: Okay.

This follow up question, which sort of touches on what you mentioned there, the why are my ectopic beats worse that they, after doing strenuous exercise, and that includes dizziness and tiredness, so they're fine during and immediately after that, the following day is awful.

Dr Tom Keeble: So, with regard to extra beats, the day after exercise, as we talked about, ectopics will usually disappear during exercise.

As the heart rate goes up, the ectopics tend to not occur so frequently usually. It's, I, I can't really explain why a whole 24 hours later you would get more of them. I don't know tha,. I don't know why.

I think if there are concerns and with any sorts of extra beats, we worry about dizziness. So if you have dizziness with that, or have concerns about extra beats, then I would seek advice from your cardiologist who will probably want to do a monitoring or monitor your ICD if you've got an ICD insight to that obviously makes life a lot easier in terms of understanding what's going on from an arrhythmia perspective. but yeah, ectopics in themselves are genuinely self-limiting and not a problem. but of course, you know that we need to tailor treatment to, to individuals from expert cardiologists.

Paul Swindell: Okay.

You touched on ICDs there. I've got a couple of questions on ICDs. I know you're not an ICD, expert, an electrophysiologist, but maybe you, maybe you can answer these.

What sorts of pains do should you expect as your ICD is healing? And what should you be concerned about?

Dr Tom Keeble: Okay, well, I think that, you know, ICD implantation is a surgical procedure, and often they put it underneath the muscle below your, your collarbone.

And so, you know, you can expect that a surgical wound is going to take at least a couple of weeks to heal and to all settle in. There's then the sort of more longer term fibrosis and really getting in a fixed position, which takes then a few more weeks thereafter. And you can imagine. If it is underneath the muscle layer and you're moving your left arm or wherever it is that the arm is closest to it, you can imagine it does take time for that sort of, that healing to happen.

Again, I think ICD patients are incredibly well followed up generally by the implanting centre and you always get a card and the number to call if you've got concerns. I think that, you know. A bit of pain for the first couple of weeks. He's absolutely to be expected, a bit of pain thereafter while it all settled in and fibrosis and gets in a nice happy position long term is to be expected, but I would always discuss it with your, ICD team and at followup, because of course the things we worry about are infection and infection can of course give you pain. So yeah.

Understand how you're feeling in other ways.

Do you have a fever?

Do you feel unwell?

Is it red?

Is it inflamed?

They are really red flag symptoms that I would want you to ring, either your doctor or your ICD team immediately. And normally ICD follow up clinics will see patients the same day if there's genuine concerns about patients. So, I think that a bit of pain is to be expected. I think if that pain is ongoing and more protracted or gets worse, that's the other thing.

Pain from a surgical procedure should get better day on day, week on week. If you noticed that it got completely better and then something new happens and it gets worse, then we would probably want to understand why that is.

We worry about redness.

We worry about infection.

We worry about the wound healing.

And so, they're really important things to, to document and to, to speak to your, team about on the number that you get given when you're discharged home.

Paul Swindell: Okay, cool.

This person was a couple of questions related to, same thing. If, if my defib or the lead is faulty, what can they do about it?

And what is the sort of procedure to rectify it?

And the second part is, is there a certain number of years after which you would not risk the removal of an ICD lead?

Dr Tom Keeble: Yeah. So, so both a good questions.so leads, you have to remember that when you put an lead in an ICD lead or any lead into the heart that's acting as a pacemaker or defibrillator, it moves a lot.

So, it will be fixed at the bottom end in the heart, in the right ventricle usually. And of course, it's fixed at the top, attached to the can and the pacemaker that does the, the pacing. And in between, there's about probably 30, 40 centimeters of lead, and this lead has to obviously be insulated. So, it's got sort of a, a coating around it.

And it also has to, move and be flexible because the hearts are very dynamic organ. And so there are two ways that the leads can become damaged. Number one is they can get fatigued over time. So from all the movement, maybe the lead moves and over five years, the, the sort of movement in the lead cause of the dynamicness of the heart causes little micro fractures in the lead, which then either stop the isolation, the, the, the coating on the outside damages that or damages the lead itself.

And we look at those parameters over time, we know exactly how much voltage is required to deliver a heartbeat to the heart. And so we can measure the impedance of the lead. And if the lead impedance is going up, we know that there may be a fault with the lead over time. So, these things can always be monitored to understand if the lead is fractured or failing.

The second thing, and this was many years ago, very occasionally, we see design fault leads and that there are recalls by companies, to say, you should really take this lead out because we don't think it's going to last. And it's faulty. And obviously that's incredibly disappointing for the company, but more over for the patient and for us as operators.

But at the same time that occasionally happens, but the common is caused is just lead failure because it's, it's run into problems because of fatigue, and as a, it's lost its ability to function properly.

Now, as you can imagine, taking a lead out that may have been in there for a number of years, can be a challenge.

We have two types of leads essentially, we have ones that are called passive fixation, and they look a little bit like an anchor, that you dropped to the bottom of the ocean. And basically you put the lead in with the anchor into the bottom of the right ventricle, and it just kind of fixes into a bit of muscle.

And over time, once it's stuck down, it will get fibrosed and it will be hard to remove. The second type of leads that we use and we're using them more and more currently are called active fixation leads. And these are want of a better term, a screw in lead, and you literally screw it into the muscle where it gets fixed.

Now you can imagine removing a screw in lead may be more straightforward because you may be able to just unscrew it and give it a little tug. And with a bit of luck it will come out. Whereas, of course, the one that has been fixed by sort of anchor technique may be really hard to pull out there. So, extraction of leads a is done by a specialist extraction team in the Essex Cardiac Centre.

We would often do it with cardiac surgery support so that if there are challenges when you pull it out and you cause some damage to the heart muscle, then you have surgical colleagues around to help you to support the patient. And that does occur in a proportion of patients, or you can just leave the lead in.

So very often because the risk of putting a lead out can be, can have significant risks associated with it. You would often just cap it off, is not going to work anymore and put a new lead alongside it that will do the job. and so there are lots of, decisions to be made as to what you do with leads and they will be made by your, your cardiologists at your center.

Paul Swindell: Okay. And, what's the sort of longest time period that, you know, the lead has been extracted?

Dr Tom Keeble: Yeah, I mean, to extract, to lead, often it will be because there's not enough space or there's infection., say often you can leave them just by the side of the other lead and the new one that you put in. I think it's difficult to know that, you know, some leads.

Yeah. The longer the lead has been in, the more difficult it is to remove, usually because it will be stuck down and fibrose. So you also have to have a really good reason to take the lead out and ensure that that's the right thing to do. And most of these decisions will go to a multidisciplinary, electrophysiology team that will decide.

Do you just put another lead in and cap off the old one? Or actually must this old lead come out? And actually, extractions are actually fleetingly rare. We don't do very many in any center in the UK because usually you can leave them be in a benign way and just put a new one next to it.

Paul Swindell: Okay.

Got a question here, which is related around,

Cardiac arrest survivors as general . why do we present such difficulties for other medical disciplines? And she's got one case he's talking about, which is, one of our members who'd had a terrible trouble with his teeth, getting them operated on. By any, anyone, I think he went all around the houses trying to find anyone who is willing to operate them. Are people just scared about how condition?

Dr Tom Keeble: Yeah, I think some of it, I think there's some naivety about your condition. Some of it, it's a bit like just having an ICD alone. A lot of people run to the Hills and don't want to do procedures on people with ICDs, but of course people with ICD still need to have tooth extractions, hip operations and other things just like anybody else.

So, I think, people can be scared because they're worried about a complication of what they do in a high risk individual, if that individual truly is high risk. but I think, as we've said before, you know, yes, cardiac arrest survivors will all have had a cardiac arrest, but in many of them, their risk of future events is modest.

And so, we need to ensure that the cardiac arrest survivors, can get the level of care they require for every type of condition, regardless of their risk.

Paul Swindell: Okay. Yes, absolutely

Paul Swindell: Well, thank you for answering all of those questions, Tom and, it's really great to talk to you again and hopefully some people have got some, anxiety release because of the answers that you've given and I hope to speak to you again soon, so if you need to take care

Dr Tom Keeble: It's an absolute pleasure.

Paul Swindell: Thanks a lot.

This concludes this episode of the Life After Cardiac Arrest podcast and I'd love to know what you think.

And you can do that via Facebook, Twitter, Instagram, or the website, SuddenCardiacArrestUK.org and you can find this by Googling Sudden Cardiac Arrest UK or the Life After Cardiac Arrest podcast.

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Presented and edited by Paul Swindell.

Recorded April 2020. 

My Coronavirus (COVID-19) experience with Dr Tom Keeble

In episode #39, Paul talks with LACA regular consultant cardiologist Dr Tom Keeble.

Dr Keeble talks about the current COVID-19 pandemic including his personal experiences as both a doctor treating patients and as someone who has has a suspected case of the disease. He also answers some questions from members of SCA UK on this topic.

Video about life after cardiac arrest features Basildon Hospital ...

Available to listen on the link below or Spotify, Apple , Google, YouTube and your favourite podcast player.

If you enjoyed this podcast please do leave a positive review on Apple or other podcast providers as it helps us to spread the word.

Presented and edited by Paul Swindell.

Recorded April 2020.