This post accompanies the podcast ‘Sudden Cardiac Death Syndrome with Harshil Dhutia at the Premier Conference 2024‘. This was recorded live at the Hope Church in Winchester as part of the PREMIER conference. We are grateful to the organising team for hosting us and allowing us to use the audio. The PIER and PREMIER websites are full of amazing resources for anyone working in Paediatric Emergency Medicine and we recommend them highly.
Listening Time – 19:20
Sudden Cardiac Death
Introduction
Sudden cardiac death (SCD) in young individuals, particularly athletes, is a tragic and often shocking event. The Premier Conference, held in Winchester in June 2024, provided crucial insights into this phenomenon. Consultant cardiologist from Leicester, Harshaal Gupta, presented an in-depth discussion on the causes, diagnosis, and management of SCD in the young. This blog post summarizes the key points from his talk, offering valuable information for healthcare professionals and families alike.
Defining Sudden Cardiac Death
Sudden cardiac death is defined as an unexpected death from a confirmed or suspected cardiac cause within an hour of symptom onset if witnessed or within 24 hours of last being seen in good health if unwitnessed. This condition predominantly affects young individuals between 12 and 35 years of age. Although rare, SCD is the leading cause of non-accidental death in young people, often striking without prior symptoms.
Recognising Symptoms and Risk Factors

In many cases, the first sign of an underlying cardiac condition is a sudden cardiac arrest. Key symptoms to watch for include unexplained syncope, particularly if it occurs during exercise, without warning, or is associated with injury. Other vague symptoms like chest pain and breathlessness can be misleading and often go unnoticed.
The major symptom that you must take seriously is syncope, particularly in the presence of red flags
- Syncope without warning
- Syncope occuring during physical exercise
- Syncope with injury
- Syncope associated with any abnormal clinical findings
Other symptoms like palpitations and breathlessness are common, but non specific.
Causes of Sudden Cardiac Death
SCD can result from various conditions, which can be broadly categorized into inherited cardiomyopathies (heart muscle diseases), ion channel diseases (such as long QT syndrome, Brugada syndrome, and CPVT), diseases of the aorta, and acquired conditions like myocarditis. Among these, inherited cardiac conditions are significant contributors to SCD.
Importance of ECG and Genetic Testing
ECG plays a crucial role in diagnosing potential heart conditions that could lead to SCD. Certain ECG patterns are indicative of specific diseases:
- Long QT Syndrome: Characterized by a prolonged QT interval.
- Brugada Syndrome: Identified by a coved-shaped ST elevation in leads V1 to V2.
- CPVT: Exercise-induced bidirectional ventricular tachycardia.
Genetic testing and molecular autopsy are vital for diagnosing and managing these conditions. They help identify the genetic mutations responsible for these diseases, which can then inform family screening and preventive measures.
Family Evaluation and Screening
Following a case of sudden cardiac death, it is mandatory to perform a specialist post-mortem to identify the cause of death. This often involves genetic testing, which can provide closure for the family and guide further evaluations. Family members of the deceased should undergo screening in a dedicated inherited cardiac conditions clinic, which includes genetic counselling and testing if a pathogenic mutation is found.
Treatment and Management
Managing young patients with inherited cardiac conditions involves a combination of lifestyle advice, medication, and in some cases, invasive treatments. Lifestyle changes may include avoiding certain medications or strenuous activities. Medications like beta-blockers can help manage symptoms, while an implantable cardioverter-defibrillator (ICD) might be necessary for those at high risk of SCD.
Exercise Considerations
One of the significant dilemmas is advising young athletes with inherited cardiac conditions on exercise. While exercise has numerous benefits, it can also increase the risk of SCD in those with underlying cardiac abnormalities. Shared decision-making, respecting patient autonomy, and individualized risk assessments are essential. Not all sports carry the same risk, and the type and intensity of exercise should be carefully considered.
Evaluating family members
- A post mortum is mandatory in the UK to try to identify the cause of death – this will include a molecular post mortum looking for potential causes.
- If a genetic cause is identified, prompt family screening should take place, ideally in a specialist clinic.
- There is currently a pilot taking place to standardise the care after sudden unexpected death.
- Many of the cause of sudden cardiac death are autosomal dominant and so there is a 50% chance of relatives having a genetic predisposition.
Emerging Technologies and Screening Programs
Advances in technology, such as implantable loop recorders, provide better monitoring for at-risk patients. These devices can continuously track heart rhythms and detect arrhythmias that could lead to SCD.
While controversial, screening programs for young athletes have shown promise in countries like Italy, where mandatory ECG screening has reduced the incidence of SCD. However, the cost-effectiveness and feasibility of implementing such programs on a larger scale remain debated.
Should all at risk get an implantable cardiac defibrillator?
These are very difficult decisions, with lifelong implications, and really only suitable for those at highest risk, to balance out the harm and benefit of the procedure
- If the patient has survived a cardiac arrest and arrythmogenic cause found an ICD is indicated.
- Those without cardiac arrest, but with high risk features (which vary condition to condition) an ICD will be discussed and ideally a shared decision made.
- Implantation of an ICD is not indicated purely to keep playing sport.
Challenges and Future Directions
There are several challenges in managing and preventing SCD in young individuals:
- Heterogeneity of Conditions: Inherited cardiac conditions are highly variable, making diagnosis and management complex.
- Limited Evidence Base: Current guidelines are often based on expert consensus rather than robust clinical trials.
- Systemic and Research Limitations: There is a need for large, long-term registries to better understand these conditions and improve care.
Conclusion
- Arrythmogenic Right Ventricular Cardiomyopathy is a particular risk, compared to other conditions.
- These decisions are not evidence based and based in expert opinion.
- The low event rates make evidence hard to gather and large registries and years of follow up are needed.
This talk highlighted the importance of a comprehensive approach to managing sudden cardiac death in the young. This includes early recognition of symptoms, thorough family screening, appropriate use of diagnostic tools, and personalized treatment plans. As we continue to advance our understanding and technology, the goal is to reduce the incidence of SCD and improve the quality of life for those affected by inherited cardiac conditions.
ECGs
Long QT

Brugada Syndrome

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Further Reading
Podcast Transcription
Good morning everyone. Now with the next 15 minutes, I’d like to talk you through the roadmap following Sudden Cardiac Death in young individuals. This is a case of a 15-year-old boy, normally fitting well, a keen footballer aspiring to become professional, with no past medical history and no family history of note. Unfortunately, he collapses while running and has a cardiac arrest. Despite bystander AED and CPR, he is declared dead at the scene. The sudden death of a young individual is a highly tragic event that has a devastating impact on friends, family, and the wider medical community. We often think of young people, particularly young athletes, as the healthiest segments of society, so such deaths are difficult for us to comprehend.
Sudden Cardiac Death can be defined as the unexpected death from a confirmed or suspected cardiac cause within an hour when the death is witnessed, or within 24 hours of last being observed in good health when the death is unwitnessed. The definition of young is very variable. Most people say it’s between 12 and 35 years of age. It’s really difficult. And that’s the problem we have in our studies on Sudden Cardiac Death. There are a lot of inconsistencies in what age groups are used. Many of you have heard of the term Sudden Arrhythmic Death Syndrome (SADS) and that’s often used interchangeably with Sudden Cardiac Death. However, Sudden Arrhythmic Death Syndrome refers to a situation where no obvious cause can be found at postmortem, and the cause of death is suspected to be cardiac in origin.
Fortunately, Sudden Cardiac Death in the young is relatively rare. However, it is the leading cause of non-accidental death in young individuals, significantly higher than cancers, significant mental health disease, and drug overdoses, for example. So it is an important public health problem. 80% of cases of Sudden Cardiac Death occur in people who have never had symptoms before, so cardiac arrest can be the first presentation of disease for the majority of individuals. When you’re working in an emergency department, what symptoms do you need to look out for? A lot of the symptoms are fairly vague, and in young populations, the yield is very low. Breathlessness, again without any physical signs, can be fairly nonspecific. But the one symptom that you should always really take into consideration and consider referring to your cardiologist is syncope, particularly with red flag symptoms such as occurring without warning, associated with exercise, associated with injury, or when the physical examination is abnormal.
There are several causes of Sudden Cardiac Death in young individuals, and we can categorize these quite nicely into four groups. The ones which I deal with in my clinical practice, and what I’m going to touch on today, are the inherited cardiomyopathies, the heart muscle diseases, the ion channel diseases such as long QT, Brugada, or CPVT. But it can be due to diseases of the aorta, for example, aortopathies, or acquired causes like myocarditis.
Everyone in the ED gets an ECG, and often you will make a diagnosis of an inherited cardiac condition in an asymptomatic patient incidentally because of their ECG. So these are just ECGs of the common ion channel diseases we see in clinical practice. This is long QT syndrome at the top left, characterized by prolongation of the QT interval, and often the T-wave will be very abnormal as well. Then it’s Brugada syndrome, characterized by this typical coved-shaped ST elevation in leads V1 to V2. It’s really important that this ECG can occur in specific situations, so in the emergency department, it’s not uncommon to see someone with a fever triggering this ECG. At the bottom is a patient with CPVT, and this is actually an exercise ECG showing ventricular tachycardia, broad complexes, a lot of ectopy, and the ectopy is actually bidirectional—it’s going down, going up, going down, going up—and this is very typical for CPVT. If you have a young person who’s had exercise-related syncope, a treadmill test is a fantastic investigation you can offer them.
I have deep sympathy for you working in the emergency department when it comes to ECG interpretation. It is not easy. Your patients will have electrolyte disturbances, they may be septic, anemic, or present with toxicity or neurological presentations which can all impact the ECG. In this situation, I simply recommend stabilizing the patient, correcting the underlying cause, and repeating the ECG.
Some of you will be interested in point-of-care ultrasound, and these are just some echocardiography images of patients with cardiomyopathy. Hypertrophic cardiomyopathy is characterized by thickening of the left ventricle septum. Dilated cardiomyopathy is characterized by dilatation of the left ventricle with reduced pumping function of the left ventricle, and ARVC, where the right ventricle is stretched and the pumping function is impaired. By far, in 50 to 60% of cases, both in athletes and in non-athletes, adolescents, the leading cause of Sudden Cardiac Death is unexplained Sudden Cardiac Death. When we evaluate family members, we find in 40% of cases, we can identify an inherited cardiac condition, particularly the ion channel diseases, long QT, Brugada, and CPVT.
Back to our case: the young boy who died of Sudden Cardiac Death. It’s mandatory by UK law for that person to have a specialist post-mortem to make a diagnosis of why the person died. It also offers an opportunity for closure for the family members. When post-mortem is taking place, genetic testing can be performed at the same time from the molecular autopsy, and genetic counseling of family members can take place if we identify a genetic alteration. While this is all taking place, prompt family evaluation and screening in a dedicated inherited cardiac conditions clinic is recommended, which would be guided by the post-mortem finding and the result of genetic testing from the autopsy. It’s really important, and something we don’t really do well enough, to offer expert bereavement support at all stages of this process. It’s incredibly tragic and the family really does need help.
Up until recently, this was done at a very inconsistent level depending on which part of the country the Sudden Cardiac Death took place, and therefore I’m really pleased to highlight this new protocol for the NHS and coronal sudden unexpected death pilot. Leicester is one of six sites in this pilot, which aims to standardize how we manage Sudden Cardiac Death, particularly to minimize missed opportunities for tissue retention at post-mortem and allow signposting of family members to a dedicated inherited cardiac conditions clinic. It really requires the collaboration of several teams: the coroner’s office, pathologists, geneticists, and the ICC cardiologists. Working in the emergency department, you may be asked to give a statement to the coroner on when someone presents with a Sudden Cardiac Death as they try to get more information about what’s happened.
Why do we need to do a post-mortem and further evaluation? Is this all really necessary? Yes, because the majority of conditions implicated in young Sudden Cardiac Death are genetic and inherited in an autosomal dominant mode. This means there’s a 50/50 chance that someone with the condition can pass it on to their children. Therefore, family history is really important when you’re evaluating a young person in your emergency department who may have an inherited cardiac condition.
The young boy who died of Sudden Cardiac Death will undergo an expert post-mortem. The pathologist will first make sure that there are no toxins, that toxicology is negative, and exclude other causes of death in young individuals. If a cardiac death is suspected, the pathologist will assess if the heart is structurally abnormal or normal. If the heart is structurally abnormal, like with cardiomyopathy, disease-specific molecular autopsy and disease-specific family evaluation is recommended. In our case, the heart was structurally normal, which essentially means Sudden Arrhythmic Death Syndrome where we need to think of an ion channel disease. Genetic testing is not a diagnostic test. We only use it when we’ve made a clinical diagnosis, and in patients with a likely pathogenic or pathogenic genetic alteration, we are confident that this alteration has caused the disease.
In our case, this young boy’s post-mortem genetic test showed a gene associated with long QT syndrome. So, we’re fairly confident given the circumstances of death that this boy died of long QT syndrome. When we move on to the family, we see this boy had a genetic alteration. His sister also has the gene, his father has the gene, his father’s brother has the gene, and his cousin has the gene. The mother does not have the gene and she can be discharged. When we evaluate the father and the sister, they both are asymptomatic but have prolonged QT intervals, fitting with an autosomal dominant mode of inheritance.
It’s really important for family members to be evaluated in a dedicated inherited cardiac condition service as recommended by the National Service Framework. These are the things we do: we try to make the diagnosis, stratify the risk, manage the case, and further assessments. In terms of treatment of young patients, unfortunately, the treatment for many of these conditions is difficult because they’re not curable and treatment is aimed at reducing the risk of Sudden Cardiac Death in those identified with the disease. Fortunately, for the vast majority, simple lifestyle advice is all that’s required, including avoiding certain medications in long QT syndrome. Many will require anti-arrhythmic drugs, some may require invasive treatments, and fortunately, only for the minority of patients at high risk of Sudden Cardiac Death, an ICD is required.
Our 16-year-old patient is adhering to the lifestyle advice and is well-established on beta-blockers. We’re often asked about ICD decisions in young patients, and these are really tricky. These have lifelong implications for that young person. This is how I approach an ICD decision in a young person: Has that person had a cardiac arrest? If the answer is yes and there’s nothing reversible, they would benefit from an ICD. If they have not had a cardiac arrest, we then assess if they’ve got any high-risk features of their condition, which can vary from condition to condition. This could be symptoms, arrhythmia, a family history, and we’re starting to understand that genetic testing may also have some prognostic implications. If these are present, we could offer an ICD, but if there are no high-risk features, an ICD is not indicated because the risk of an ICD completely outweighs the benefit.
Fortunately, our young patient does not have any high-risk features associated with the diagnosis of long QT syndrome. She wants to play football at a semi-professional and potentially at a higher level. What would you recommend? Keep playing, retire, play only if she gets an ICD, play as a goalkeeper or play at a lower level. What do the audience think? Keep playing, brilliant.
The benefits of exercise are unquestionable. We all know there’s nothing like prescribing exercise to our patients, but then we see this exercise paradox when we see these scenes on our televisions of young athletes having cardiac arrests on the sporting arenas. We don’t really understand exactly why exercise can increase the risk of Sudden Cardiac Death in those with preexisting cardiac disease, but we can postulate that there are several mechanisms that can increase the risk in someone with an unstable electrophysiological substrate. I spend a lot of time talking about exercise considerations for young patients with inherited cardiac conditions. One of the most important developments over the last few years has been this concept of shared decision-making, respecting their autonomy, individualised approach, and assessing the risks of not exercising as well.
We have to be honest with our athletes and young individuals that the current evidence is based on very limited data, essentially expert consensus, and it’s really difficult to define how much exercise is too much. Not all sports are the same; some sports are associated with higher risk, particularly the stop-start sports. What about the impact of exercising on third-party athletes, for example on a Tour de France or skiing? Syncopy could be fatal, not only for that athlete but for other athletes as well. Not all conditions carry the same risk. The one condition consistently shown to be associated with a higher risk of exercise-related Sudden Cardiac Death is arrhythmogenic cardiomyopathy, but for the vast majority, particularly if they are under follow-up and treated adequately, they can continue with some level of competitive sport. It’s important to state that implantation of an ICD does not reverse the recommendation to avoid exercise. We are hopeful that the ICD is only going in for those considered at the highest risk. Putting an ICD to allow sport is a no-go.
We’ve seen from this case and this family that there are major challenges we face in evaluating or caring for patients with inherited cardiac conditions who may be at risk of Sudden Cardiac Death. There are disease factors that make things challenging. These are highly heterogeneous conditions with a really variable natural history. There is a poor relationship between the genotype and the phenotype, including in this family where two family members with the same genetic alterations, one has a cardiac arrest and one is asymptomatic. The conditions are not curable, and unfortunately most guidelines currently are still based on very limited evidence. We don’t have randomized control trials in inherited cardiac conditions. There are some patient factors that make things challenging. These are often very young patients, and often asymptomatic patients who have been told they have a condition that could potentially kill them. There are implications for lifestyle, as you’ve seen in terms of exercise and occupation, and of course given the genetic nature of these conditions, there are significant implications for reproduction and some ethical issues in relation to genetic testing.
There are also system and research limitations in these conditions. These are highly specialized conditions and there is significant regional variation in the availability of specialists to care for such patients. To make a service work, it requires the active collaboration of several clinical teams and often these logistics can be difficult in most NHS hospitals. Given the relatively low numbers and low event rates, to really understand the natural history of these conditions, we need large registries with decades of follow-up.
In these 15 minutes, I’ve been able to go through the roadmap following Sudden Cardiac Death, talking about what are the causes of Sudden Cardiac Death, how relevant they are to public health, how we evaluate family members after Sudden Cardiac Death, and the role of the inherited cardiac conditions clinics in caring for these young patients with these conditions and how we treat them, which may be from medications, lifestyle advice, and more invasive treatments. Thank you very much.
I wondered if you could talk to us a little about the roles for other implantable devices like loop recorders and whether there’s emerging technology that might reduce the risks and enhance benefits for different patients. Historically, as clinicians, we used to request a lot of Holter monitors, but I must admit the diagnostic yield of 24-hour tapes is a waste of time. I just can’t remember the last time it actually changed anything. So I generally don’t request Holter monitors. I do encourage patients, obviously I don’t promote it, but I encourage them to think about smart apps. Those are really helpful because they provide a really good opportunity for rhythm correlation. Looking at the apps on Apple or AliveCor, they’re really good because the patient has symptoms, and we can see the ECG trace at that specific time. That’s really helpful.
I like loop recorders a lot. These are implantable loop recorders, small chips which we place under the skin under local anesthetic. They can last for about three years, and if you have patients with unexplained syncope, it’s a really good way of monitoring them for up to three years. It’s all done remotely, so they get a monitor which they plug in at home. They don’t have to keep coming back to the hospital, but if they were ever to have an event, a syncope event, we would be able to know if there was an arrhythmia or not before they knew. So I like implantable loop recorders a lot and I routinely use them for patients with syncope rather than things like 24-hour tapes.
Is there a place for screening of young people with cardiac risk and is there any evidence base for that? Thanks for that question. Screening is implemented at the highest level of sport as routine. How we screen is always a bit debatable. You’ve already seen that for the majority of individuals at risk of Sudden Cardiac Death, they are asymptomatic. Symptoms are actually a waste of time if you’re screening. The family history can be helpful, but often they may not even know a family member has the condition because the family member is asymptomatic. So the history and family history are not particularly helpful screening tests. Physical examination is often normal in these patients, so physical examination is also not really a helpful screening test.
The 12-lead ECG is routinely part of screening at higher-level sport. It can identify the majority of individuals with inherited cardiac conditions, but it’s not perfect like all screening tests. It won’t pick up every single person with an inherited cardiac condition. For example, patients with aortic diseases will have a normal ECG. Patients with CPVT will have a normal resting ECG. In terms of the evidence, the best evidence we have comes from Italy where screening of young athletes is mandatory by law. You can’t get a gym membership in Italy without having a screening ECG. In Italy, they’ve shown a significant reduction in the risk of cardiac events following the introduction of screening. This has not been replicated anywhere else in the world. One of the criticisms of screening has been worrying about false positives. How can we interpret the ECG? These are often challenging rhythms to interpret and that’s one of the criticisms. Although the false positive rate in expert hands is under 2%, which is better than most other screening programs.
Another concern is the cost. Can we afford it? We have a lot of young people exercising in the United Kingdom. Can we really afford a national screening program? In 2019, the National Screening Committee reviewed screening and voted against it, but that’s up for further review. There’s a lot of push from charities, for example, Cardiac Risk in the Young, that is promoting screening of young individuals. It seems to work, but there are ethical issues. Why is it only for the highest level of sport? What about the other young individuals who are just as likely to have a cardiac arrest? These are genetic conditions. They don’t have a unique predilection for competitive sport. Young people are more likely to exercise without an AED. So at the moment, it’s still not been passed by the National Screening Committee, but I believe they’re looking at it this year again.
The Speaker – Harshil Dhutia
Harshil Dhutia is a consultant cardiologist at Glenfield Hospital, University Hospitals of Leicester the lead for inerited cardiac conditions service in the region, providing specialist care for patients with genetic heart diseases and their family members. He is a International Board of Heart Rhythm Examiners certified heart rhythm specialist for all aspects of cardiac device implantation and management including pacemakers, defibrillators and cardiac resynchronisation therapy. He is an expert in sports cardiology and has extensive clinical and research interests in the management of competitive and recreational athletes with cardiovascular disease. He is the medical lead for the Joe Humphries Memorial Trust, a Leicestershire based charity that raises awareness of sudden cardiac death in young people and provides cardiovascular resuscitation and AED training in schools, sports clubs and to members of the community.

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