Can exercise cause trouble for my heart?

Everyone thinks exercise is good for you. It certainly is! Being fit does reduce the chance of health problems including heart attacks strokes and diabetes.

But it becomes more complex if you have heart problems. People who have had heart attacks are offered cardiac rehab to put them through a graded exercise program to get them back into safe levels of exercise.

Some people have inherited problems such as hypertrophic cardiomyopathy which can increase the risk of heart rhythm problems with exercise.

Very rarely, these can result in cardiac arrest with dramatic examples such as Fabrice Muamba collapsing on the football pitch during a premier league match.

To combat this professional athletes undergo screening for cardiac disorders.

Last month Professor Sanjay Sharma published the results of his experience screening adolescent footballers. This study was funded by the English football association and its great to see them taking this issue seriously and perhaps more so than the US national (American) football league and their ongoing problems with chronic brain injuries.

I have worked with Prof Sharma previously on similar screening events of England cricketers and Manchester City football club, so I know how much work is involved as well as the worry it brings when something abnormal is found.

But this study has covered many more people to give us much better data. They looked at 11,148 players with an average age of 16 over a 20 year period. 95% of these were male. 42 players were found to have a cardiac disorder with a risk of sudden cardiac death. A further 225 had other cardiac problems that were picked up.

The players were all youth players at English professional football clubs. The 42 players who were found to have cardiac disorders associated with sudden cardiac death were advised not to compete.

After follow up (obviously of varying durations – 20 years for those screened at the beginning, down to 2 years for those at the end), 23 people had died, 8 of which from Cardiac causes.

Clearly the risk of cardiac problems is small but not zero in these players, with 0.38% if screened players having a Cardiac disorder associated with sudden cardiac death, and 2% having some form of cardiac problem.

We don’t know how effective screening is at preventing problems – this study doesn’t address that as there is no control group, but it does tell us that screening is not perfect at preventing sudden Cardiac death and some problems are not detected at the point of screening.

Nevertheless the absolute risk is small.

The big gap now in my mind is the risk in veteran athletes – the MAMIL’s or middle aged man in Lycra – or people like me!

There is a growing trend for fitness and certainly there are far more middle aged people cycling / doing triathlons / marathons and so on.

Every year there seems to be a death in the ride London event. There’s no data to show that screening in this population picks up treatable conditions but I would certainly want to think about it before I took on a big race or competition.

 

Chest pain – is it my heart?

Chest pain

It may be nothing, but it may not be…

I’m not trying to scare you, but heart attacks are deservedly scary.

The standard advice is if you have chest tightness that lasts for more than 15 minutes is to call an ambulance.  Particularly if the pain goes to your arms or neck, if you feel hot and sweaty, or if you feel dizzy.  The pain may be in the upper abdomen and be confused with indigestion, or go through to the back.  These are all worrying symptoms.

Heart attacks are due to a blockage of the heart arteries usually due to the lining of the artery breaking open and a clot forming.  How severe the heart attack depends on the location of the clot (at the beginning of a large artery = large heart attack, at the end of a small distal branch artery = small heart attack), and on whether your body dissolves the clot by itself, or if it is unblocked by drugs or an angioplasty.

But the people I tend to see in clinic as opposed to the Emergency department are those who have less severe symptoms or have been to hospital and had a heart attack excluded.

Here there is time to take a proper story of the pain as this gives the answer in most people.  The characteristics of pain due to heart artery narrowing are a dull heavy feeling in the centre of the chest, that can go up to the neck, jaw or left arm.  It reliably comes on with exercise and goes away with rest.  This classical history is almost certainly  due to the heart, and is known as angina.

Obviously many people don’t have a classical history.  Symptoms are often different in women, and in patients with diabetes.

In cases of clear angina it is sensible to do an angiogram to have a look at the arteries and identify narrowing.  In cases where it is not clear it may be worth doing non-invasive tests to look for artery narrowing or the functional effect of narrowing.  These investigations can determine if further medication, stents, or surgery is needed.

Other causes of chest pain include musculoskeletal problems, acid reflux or lung problems such as pleurisy pneumonia or clots.

If you are worried about chest pain, it is worth getting a specialist opinion.  Feel free to contact me to arrange an appointment where we can spend some time going through your symptoms and deciding if you need any tests.

 

Medicines for rhythm problems

There are lots of medicines out there for heart rhythm issues.

The first line that are beta blockers (eg bisoprolol) or calcium channel antagonists (eg diltiazem).  These generally slow the heart and can reduce extra beats, but aren’t very good at keeping you in a normal rhythm.

Anti-arrhythmic drugs can keep you in a normal rhythm. The most effective is a drug called amiodarone. This is a very powerful anti-arrhythmic, but it’s by no means perfect. It increases the time to recurrence of atrial fibrillation, reduces recurrent symptoms but doesn’t abolish them (ie it’s not 100% efficacious – probably more like 60%).  It does reduce ventricular tachycardia episodes.  It is overkill for supraventricular tachycardias and hangs around for ages so is generally avoided in this situation.

It also has lots of potentially nasty and lethal side effects. Most of these only occur after prolonged exposure after many years or decades but some can occur early. Initially the drug was used at doses of 400mg a day, but now we commonly use it at 200mg or even 100mg a day. The commonest side effects include problems with the thyroid gland but it can also cause grey discolouration of the skin, sensitivity to the sun, deposits on the surface of the eye causing issues with glare of vision particularly at night, taste problems, lung fibrosis, liver problems, damage to the peripheral nerves.

There are alternatives. The great hope for atrial fibrillation was dronedarone which was supposed to be as good as amiodarone but safer. It actually has the best evidence base of any antiarrhythmic ever but is probably as it is the latest drug. Unfortunately it doesn’t seem to be as good as amiodarone and is dangerous in people with impaired heart function and has a warning against it that it can cause fulminant liver failure so it’s not popular with doctors.

Flecainide or propafenone are pretty good in patients without heart disease and are pretty safe. In fact flecainide is my go to antiarrhythmic in pregnant patients. Sotalol is another option but isn’t particularly effective.

It can be quite complex choosing the right medication for yourself so it’s always helpful to see a specialist to discuss options and come up with a tailored personalised management plan.  Feel free to get in touch and make an appointment

Atrial fibrillation – rate control, but how?

So we’ve decided that rate control is the best way forward for you – but how do we achieve it?

The mainstay is medication and there are different types that can be used.

First line are beta blockers such as bisoprolol.  These are usually very safe and well tolerated.  They can be taken safely for many years.  They can even be used in pregnancy!  The most frequent side effects that people complain to me about is feeling cold, and the second is that they can make some people feel tired.  Some people complain about vivid dreams.  There are of course other side effects noted in the sheet you get with the medicines, but these are the ones I hear about in the real world!

If these don’t suit a calcium channel antagonist such as diltiazem can be helpful.  Again, usually well tolerated and safe.

If these don’t do the trick or can’t be used because of low blood pressure then digoxin is a reasonable choice.  This is a drug that is made from the foxglove and has been known about for centuries.  It is quite effective, but oftentimes doesn’t control the heart rate on exercise so isn’t so suitable for active people.  I’ve linked a short film made a long time ago by one of my mentors Dr Holman for the Wellcome foundation.

Occasionally of course combination of these medications need to be used.  The alternative is a “pace and ablate” strategy where a pacemaker is implanted and the electrical connection between the atria and the ventricles is ablated thus making the ventricular rate controlled by the pacemaker.  This can be very effective in dealing with symptoms because it results in a regular pulse as well as a normal heart rate.

 

 

Ablation – for heart rhythm

Ablation really just means the destruction of cells.  When applied to heart rhythm problems it means we can treat heart cells that are causing trouble.

It is done by using one of 2 technologies – either microwave energy to heat cells, or liquid nitrous oxide to freeze cells.  These cause the proteins in the cells to change their structure and stop the cell from working.

The heating or freezing is done via catheters which are introduced to the heart via the veins (or sometimes arteries) in the groin.  They are long and thin, usually about 3mm in diameter, though some can be significantly larger.

Different rhythm problems are due to different causes – either cells are over-active, so fire too much, or conduct slowly allowing electrical circuits to be set up inside the heart.

In atrial fibrillation we have learnt that dealing with the over-active cells in the veins as they enter the heart can lead to narrowing of the veins, so it is safer to electrically isolate the veins from the atria by burning or freezing around the veins.  This can be known as Pulmonary Vein Isolation (PVI) or Wide Antral Circumferential Ablation (WACA).  We doctors do like our acronyms!

Like any procedure, there are risks and benefits.

On the benefits side, they can cure rhythm problems, particularly supra ventricular tachycardias, or at least improve symptoms for example for atrial fibrillation.  The exact benefit depends on the condition being treated.

On the risks side they can cause problems inside the heart such as destroying normal conduction tissue so a pacemaker is needed, or causing a heart attack or stroke. There can be bleeding around the heart or damage to structures near the heart such as the veins, the gullet, or the nerve to the diaphragm.  There can also be problems in the groin where we access the veins such as clots in the veins or damage to the artery or nerves near the veins.  The risks do depend on the condition being treated.

Hopefully that is some information for you that will help you understand what might be happening.  If you want specific information, please don’t hesitate to get in touch and arrange an appointment.

Palpitations – should I be worried

Palpitations are one of the commonest things that people come and see me about.

A palpitation is being aware of your heartbeat. It doesn’t have to mean that anything is wrong and most people are aware of their heartbeat at some point or other, even if it is just with exercise or if lying in bed quietly at night and the loudest thing is your heart.

Sometimes people find they are aware of their heartbeat at other times and that the speed or rhythm of the heart is different to normal. This can be worrying.

The commonest cause of palpitations is the occasional ectopic beat. These tend to come in either single beats or a few beats clustered together. The classical description is someone who says that they are aware that their heart skips a beat every now and again. It is often more prevalent when you are not doing very much because that is when your mind can be free to concentrate on these sensations.

The reason it feels as if the heart is skipping a beat is the extra beat usually comes at an earlier time than the normal beat would be expected. At this point the heart would not have had enough time to fill properly and therefore the amount of blood ejected in that heartbeat is low. There is a compensatory pause before the next normal heartbeat and this means that the heart has had more time to fill and therefore when it beats with that normal heartbeat, it tends to be stronger and therefore it feels as if it is a really strong beat, so this is why people tend to say that their heart has missed a beat because they do not feel the extrasystole but they feel the harder normal beat after the extrasystole. It is completely normal to have a few of these every day.

Nobody really knows what tends to bring them on but there does seem to be some association with stress and certainly it is well recognised that people can become more aware of them during stressful periods in their lives and even after the stressor has gone, then the recurrence of these extrasystoles can be quite uncomfortable partly because it is associated with the feelings of stress that make them noticeable in the first place. The important thing is to make sure that there are not too many of them because very high numbers of these extra beats for example more than 20,000 a day are associated with heart failure.

It is also worth testing to make sure that there are not any other rhythm problems. Atrial fibrillation is probably the commonest rhythm problem overall and this is associated with the heart beating irregularly. These episodes tend to be sustained over a longer period. It is worth picking up as its treatment is quite different. There are also other sustained rhythm problems which are regular such as supraventricular tachycardias or ventricular tachycardias and again these are worth picking up because the treatment is different, they can be associated with other heart disease and they can be treated with drugs and/or ablation treatment.

If someone does have common or garden palpitations/extrasystoles, then I usually try reassuring them in the first instance and hopefully that can be enough to make sure that no one is worried about it. Drugs such as beta blockers or calcium channel blockers can be helpful if they remain bothersome but these are used for symptom relief only. For those people who have so many extra beats that heart failure is an issue (usually where every 5th beat is an extra beat or more), ablation can be performed but in order to map these in the catheter laboratory they need to be happening very frequently.

So I hope that is some useful information on palpitations for you. If you have any further questions, please do not hesitate to get in touch by calling me on 01634 510 521 or emailing so that we can make an appointment and get you checked out.

Atrial Fibrillation – rhythm control, but how?

So maybe we’ve done rate control and you’re still not ok.  Or perhaps the atrial fibrillation is at the stage where it comes and goes.  Maybe we should try to get and keep you in a normal rhythm.

There are a few strategies to do this.

The simplest is a DC cardioversion.  This uses an electric shock across the heart to reset the atrial rhythm.  The good news is that this is quick, almost always works initially.  The bad news is that if you’ve had atrial fibrillation for more than a day, you should be on anticoagulants to prevent blood clots from forming in the atrium.  It’s also quite painful so needs to be done under deep sedation or a general anaesthetic.

The other bad news is that the atrial fibrillation can start again.  Sometimes it can recur quite quickly.  Medications can be used to try to keep you in a normal rhythm.  In the UK, the commonly used ones are amiodarone, flecainide, sotalol and possibly dronedarone. These can successfully control the rhythm but are not perfect, but are certainly worth trying.

There is another strategy which is a procedure called ablation.  Current guidelines suggest that ablation be offered if drug therapy doesn’t work, but more data is being published to say that it is a reasonable first line option in atrial fibrillation that comes and goes (paroxysmal).

Ablation refers to a procedure where we selectively treat part of the heart muscle to prevent rhythm disturbances.  For atrial fibrillation, it seems that the trigger for atrial fibrillation is electrical activity coming from muscle sleeves around the veins from the lungs as they empty into the left atrium.  So in ablation, we either freeze or microwave tissue around the veins to electrically isolate the veins from the atrium.  The medium term success rates for ablation in patients with paroxysmal atrial fibrillation is above 70%, though some patients will need more than one procedure.  For persistent atrial fibrillation (ie the heart is in atrial fibrillation for more than a week, or needed drugs or cardioversion to restore normal rhythm), the medium term success rates are more like 50%.  It’s important to know that lifestyle measures such as weight loss do significantly improve the success rates so this is extremely important.

Bad news about ablation – like any procedure there are risks associated with it such as groin damage, bleeding around the heart, damage to the nerve to the diaphragm resulting in breathlessness and very rarely heart attack, stroke or damage to the gullet which can be fatal.

It’s worth speaking to a specialist to discuss the best strategy for you as it can be quite a complex decision.

Atrial fibrillation – rate or rhythm control?

So if you have atrial fibrillation what’s the first thing that needs to be sorted?

In the absence of medicines or heart disease the heart races at over 150 beats per minute. This can feel very uncomfortable – a sensation the heart is racing combined with breathlessness and fatigue. If there are other heart problems such as coronary artery disease it can make these more troublesome and cause worsening chest pains.

Surprisingly some people don’t have any symptoms and it’s picked up incidentally! If untreated this can cause the heart to wear out – the ventricles contract more weakly – a condition called tachycardia cardiomyopathy.

So the first goal is to reduce the heart rate. This can be achieved by medication – beta blockers, calcium channel blockers or digoxin. These all slow conduction in the atrioventricular node and therefore slow the ventricular rate.

But rewind a bit – if the atria are fibrillating, shouldn’t we fix it?

Well, yes, that is the logical thing to do. But being cardiologists we are not satisfied with mere logic, we want evidence.

It is relatively simple to reset the heart from atrial fibrillation to normal (sinus) rhythm. In fact in many people the fibrillation lasts less than a day, but these episodes (or paroxysms hence the term paroxysmal atrial fibrillation) have a tendency to become more frequent and last longer before becoming persistent.

At the turn of the century cardiologists performed a trial to test if patients did better with a rate control strategy or with a rhythm control strategy. This was the AFFIRM trial which published in 2002. This landmark study of 4060 patients showed that there was no benefit to a rhythm control strategy compared to a rate control strategy. In fact, there was a trend towards a lower death rate in the rate control group (but statistically this did not reach significance). Quality of life was assessed and not found to be different between the 2 groups but the method of assessing this and the results are not quoted in the original paper.

This has led to guidelines recommending rate control as the initial treatment strategy. But there are important caveats to this. The trial only enrolled patients above the age of 65, so it’s findings are not applicable to younger patients. Secondly, the use of anticoagulants to prevent stroke was a little worse in the rhythm control group at around 70%, compared to the rate control group at 83%, because the trial protocol allowed for discontinuation of anticoagulation in the rhythm control group. This may account for inferior outcomes in the rhythm control group. Finally, of course, our treatments for rhythm control have expanded since 2002 (the subject of a future post)

In the AFFIRM trial only a single patient in the rhythm control group underwent ablation of atrial fibrillation (the seminal paper which described this was only published in 1998) which has become an important tool in the intervening years.

So we know that rhythm control or rate control with medicines are equivalent options in the treatment of atrial fibrillation when it comes to hard outcomes like death rates.

But that’s not to say there aren’t symptomatic improvements with rhythm control. This is where it is important to see an expert to tailor the treatment strategy to you personally as opposed to what’s good the population. A good doctor will explain all the options for treatment strategies for rate or rhythm control, anticoagulation and the importance of lifestyle factors, discover what goals are important to you and help you achieve them.

Atrial Fibrillation – an introduction

Lots of people come to see me with atrial fibrillation or AF as it’s often known.  While they might have been given a diagnosis, they often haven’t had time to discuss the implications and options for treatment.

The problem is that Atrial fibrillation is both incredibly simple and quite complex at the same time.

When I asked one of my junior doctors to do a presentation on it – he said that would only take half an hour, not realising that you could easily write an entire textbook on the condition!

So here is some useful information as a starter – there’ll be some follow up posts in the coming weeks.

The heart has 2 atria and 2 ventricles.  The atria collect blood from the body and pump it into the ventricles which then pump blood around the lungs and the body.

Latidos

In atrial fibrillation the atria don’t pump properly – the electrical activity in the atrium is chaotic rather than regular and this means the tissue is writhing rather than a coordinated pumping.

This leads to two consequences.

Firstly, the atrioventricular node (shortened to AV node), the only normal electrical connection between the atria and the ventricles is bombarded by the chaotic electrical activity of the atrium at over 300 times per minute.

Fortunately it can’t work that fast, but it will be activated and trigger the ventricle irregularly at usually between 150-230 beats per minute.

This means the pulse is fast and irregular.  Not all the heart beats can be felt in the pulse at the wrist because the heart may not have enough time to fill properly and therefore the ventricles may not pump a lot of blood with every heart beat. Feeling the heart beat itself on the chest or the pulse in the neck is probably a better way of working out the heart rate.  But to clinch the diagnosis, an ECG (electrocardiogram) is needed.  This can even be done using smartphone or smart-watch accessories!

Secondly, because the atria are not contracting properly in a coordinated way, blood can stagnate within the atria and form clots, usually in part of the atrium called the appendage.  Not really a problem if the clots stay in the atrial appendage, but if a bit breaks off, it can cause a stroke.  This is one of the commonest causes of strokes and it actually tends to cause worse strokes than other causes.

So the initial treatment of atrial fibrillation focusses on controlling the ventricular rate and on assessing the risk of stroke.  That will be the subject of another post!

 

His Bundle pacing

This is a really funny name.

It makes no sense to anyone except Cardiologists who remember that there was a person who identified a bundle of specialised conduction tissue within the heart.  That person was Wilhelm His Jr, hence the name “Bundle of His”.

It is pronounced Hiss rather than Hiz, by the way.

So what’s all the excitement about?

Well the Bundle of His is part of the normal wiring system of the heart and is responsible for carrying signals from the atrioventricular node down to the ventricles.

We have learnt that even in patients whose atrioventricular node doesn’t work properly, we are able to pace the Bundle of His and stimulate the ventricles via the rest of the normal wiring system.  This looks very pretty on an ECG!

This has been very challenging to do in the past, but newer techniques have made it more feasible.

Observational data from 765 patients in the USA has demonstrated that this is a safe and feasible technique, and suggests that it reduces the combination of death, heart failure or an upgrade to a more complex pacemaker.

This is only observational data, but there is growing evidence to suggest it might be better and worth a proper randomised study.

I’m pleased to be offering His bundle pacing to my ICD patients as part of the Hope-HF study for which I’m a Principal Investigator.  This is a study coordinated by Imperial College, London and I performed the first His bundle pacing in Medway last year.  It’s too early to know if it’s helpful in that population, but I’m sure we will see more interest in the pacemaker population in the coming yearsHis Bundle Pacing Electrogram