Understanding sudden death syndrome – Pt1
SUDDEN death can be one of the most traumatic events for both families and health-care providers and has devastating social and economic impacts that extend beyond immediate family circles to the wider society.
It inflicts collective trauma on the society, and this is readily apparent in the immediate aftermath of sudden death episodes, especially in places like Jamaica with poorly coordinated emergency response networks and weak cardiovascular care infrastructure where happy endings are not usually the case as opposed to the illustrative cases in the USA and Denmark. It exposes our collective vulnerability and impotence in responding to such a public health concern.
Take for instance 24-year-old NFL player Damar Hamlin who, after suffering a sudden cardiac arrest during a Buffalo Bills game earlier in the week, remains in critical condition in the intensive care unit but is showing signs of improvement. Hamlin benefited from prompt cardiopulmonary resuscitation and his heartbeat was restored on the field before he was transported to the University of Cincinnati Medical Centre where he remains sedated and on a ventilator. The cause of his cardiac arrest remains unclear.
Here in Jamaica, the sudden death of Richard Bernal, Jamaica’s former ambassador to the United States, was reported just a short while ago, apparently from cardiac arrest. Bernal reportedly collapsed while walking in Norbrook, St Andrew, with his wife. It is unclear if cardiopulmonary resuscitation was initiated and to what extent resuscitative efforts were administered.
In April 2021 we published an article in our column here highlighting sudden death and proffered recommendations for a systematic approach to reducing the risk of sudden death within the population. In June 2021 we followed up with another article on cardiac arrest in the young following the cardiac arrest episode of young Christian Erickson, a Danish footballer who suffered a sudden death episode on the pitch at Parken in Copenhagen during his side’s Euro 2020 Group B match with Finland. This tragic event was telecast to a live audience of thousands of viewers around the world. Fortunately, as with the 24-year-old Damar Hamlin, the 29-year-old midfielder was successfully resuscitated and was fitted with a heart starter, implantable cardioverter defibrillator (ICD) to protect him from further sudden death episodes. In a testament to modern science and good quality health care, in January 2022 Erickson returned to the Premier League as he signed a six-month contract with newly promoted Brentford. This is validation of the need to develop a functional cardiovascular care infrastructure even here on our own island.
It is imperative therefore that we must continue to work towards resolving the friction points that impede rapid access to appropriate care while concomitantly working to encourage the development of high-quality health-care systems anchored on international standards and best practices. Even though many causes of sudden death are not fully characterised, most sudden death episodes have an underlying cardiovascular cause, so improving overall cardiovascular prevention and treatment strategies within the population will have a major impact in identifying individuals at risk for sudden death and will help in proactively acting to reduce or mitigate those risks.
Understanding sudden death syndrome (SDS)
Sudden death syndrome (SDS) is a generic phrase used to define a complex group of cardiac-related conditions that predispose individuals to cardiac arrest, and ultimately death, in the absence of prompt cardiopulmonary resuscitation followed by definitive care in a cardiac intensive care unit — which most likely would include prompt placement of an implantable cardioverter defibrillator. While cardiac arrest is not the same thing as a heart attack it must be noted that a heart attack may lead to sudden death, and so in both situations timely intervention is critical to prevent death.
Cardiac arrest remains a public health crisis. According to a recent report from the American Heart Association (AHA) titled Heart and Stroke Statistics-2022 Update, more than 356,000 out-of-hospital cardiac arrests (OHCA) occur annually in the US, nearly 90 per cent of them fatal. The incidence of non-traumatic OHCA in people of any age attended by emergency medical personnel in the USA is estimated to be 356,461, or nearly 1,000 people each day. Survival to hospital discharge after EMS-treated cardiac arrest is only about 10 per cent. Figures for Jamaica are unknown but most likely not comforting.
It is estimated that sudden cardiac death occurs every three days in the United States among competitive athletes. We do not have reliable information on the prevalence of sudden cardiac death among athletes in Jamaica but, based on media reports, we believe that the incidence is rising both for young athletes and the general population.
The frequency at which sudden death episodes occur by sex, age, race, nationality, and sport is also not fully clarified. However, an estimated 3-15 per cent of athletes at risk for sudden death may be identified through structured and standardised screening. Such young athletes may benefit from structured evaluation using the HIC Play Smart Cardiovascular Screening programme which provides systematic evaluation with a structured medical history and examination, complemented with other cardiovascular diagnostic testing modalities including echocardiograms, stress testing and ambulatory electrocardiogram monitoring as directed by the risk profile. This template can serve as a foundation for an organised national screening programme for Jamaica.
There are several challenges to understanding the epidemiology of cardiac arrest. Despite being a leading cause of death in many countries, there are currently no global standards for surveillance to monitor the incidence and outcomes of cardiac arrest. Currently, registries and clinical trials are the only tools used to provide best estimates.
Structural abnormalities in the heart or problems with the electrical channels and conduction systems in the heart account for many cases of sudden death. Heart function depends on proper function and synchronic coordination of the electrical and mechanical systems of the heart. Any disturbance in the origination or transmission of electrical signals will ultimately impair the mechanical function and may predispose individuals to sudden death episodes. Some of these disorders may have genetic or familial predispositions and, in such cases, clusters of sudden death episodes may be seen within families. Because many individuals at risk may appear healthy and are asymptomatic or have infrequent symptoms, many people at risk may not be recognised until a sudden death episode occurs.
Next week we will look at who is at risk for sudden death and recognising early symptoms of sudden death.
Dr Ernest Madu, MD, FACC and Dr Paul Edwards, MD, FACC are consultant cardiologists for the Heart Institute of the Caribbean (HIC) and HIC Heart Hospital. HIC is the regional centre of excellence for cardiovascular care in the English-speaking Caribbean and has pioneered a transformation in the way cardiovascular care is delivered in the region. HIC Heart Hospital is registered by the Ministry of Health and Wellness and is the only heart hospital in Jamaica. Send correspondence to info@caribbeanheart.com or call 876-906-2107