Tag: sudden cardiac death

Categories : Cardiovascular Disease ExerciseTags :

Preventable Cardiac Deaths during Marathons are Down

On By ModernMedia
Photo by Barbara Olsen on Pexels

While more people than ever are running marathons in the U.S., the risk of dying from a heart attack during a run has fallen dramatically in recent years. That’s a key conclusion from a new study by Jonathan Kim, associate professor in the Emory School of Medicine. Kim’s research is a follow-up to a study he published in 2012 — the first investigation into unexpected cardiac arrests during long distance running events.

The new findings, published in JAMA, indicate that, while the rate of marathon runners who suffer cardiac arrests remained unchanged, their chance for survival is twice what it was in the past. Far fewer marathon runners who suffer cardiac arrest are now dying of it.

“We continue to see media reports about unfortunate cases of cardiac arrest during long distance running events,” Kim says. “But, has the incidence of these events changed? Have there been changes in the most common causes of cardiac arrest? What are the factors associated with death and survival? It was a novel question to ask 13 years after our first analysis, and an important one because recreational running continues to increase in popularity.”

The challenge of finding data

More than 29 million people completed marathons in the U.S. between 2010 and 2023, triple the number of the previous decade, which Kim examined in his first study. There’s no central registry of race-related cardiac events, so for both studies, his team had to find their data through a range of sources, starting by contacting individual race directors.

“We leveraged a few sources including a comprehensive review of media reports,” Kim says. “We also had contact information for all race directors and were able to reach approximately 70% of them who helped and told us the number of events during this specific timeline, including if the individual died and the sex of the participant.”

The researchers used extensive public internet searches to identify and reach out to runners who survived cardiac arrests or next-of-kin to construct detailed profiles of as many cases as possible. “The vast majority of cases were identifiable by public search engines. And all of the deaths were as well,” he says.

Analyzing this extensive database, Kim found that while the rate of cardiac arrests was about the same during the two periods — .60 per 100 000 participants now versus .54 per 100 000 participants in the earlier period — the rate of deaths from these cases, however, fell by half: from .39 per 100 000 to .19 per 100 000. That’s about a 50% decline in the death rate since 2000–2009. As before, cardiac arrests remained far more common among men than among women and more common in marathons than half marathons.

The sport’s growing awareness of cardiac death risk

What led to the dramatic change in death rates? Kim thinks the whole sport has become more aware of the risks and of the need to have emergency services available to runners, a conclusion he reached after interviewing as many survivors as he could find. “What we found was that every one of those people got hands-on cardiopulmonary resuscitation, but the vast majority also had immediate access to an automated external defibrillator. That’s the difference,” he says.

That survival rate is comparable to the cardiac arrest survival rate in other public places that now make defibrillators routinely available such as airport and casinos, which have seen similar declines in deaths.

Kim says his findings offer additional evidence of how important it is to make CPR training available to race participants and to strategically place defibrillators along the racecourse. It’s also important, he says, to better identify the most vulnerable in a population before they run a race.

“These are more often potentially preventable events,” he says. “Being able to identify people, more commonly older individuals with unrecognized cardiovascular risk factors, doesn’t mean they can’t run a race. Rather, it affords the opportunity to improve primary preventive cardiovascular care and potentially further reduce the risk of cardiac arrest during these events. The incidence of sudden cardiac arrest during long-distance races hasn’t changed in over twenty years. I think this is an important arena of future research.”

Source: Emory Health Sciences

Categories : Cardiovascular DiseaseTags :

Exploring the Mysteries of Sudden Cardiac Death

On By ModernMedia
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In August 2007, a soccer match took place that fans of the club Sevilla FC will not forget: the 22-year-old Antonio Puerta suffered a cardiac arrest and collapsed on the field, passing away in hospital a few days later. It was later discovered that the player was affected from a condition named arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy can lead to sudden death, and it particularly affects young athletes. Using genetically modified mice, which develop a similar disease to humans, researchers identified previously unknown mechanisms and potential therapeutic targets. Their results were published in the journal Circulation.

This inherited disease is estimated to occur at 1 in every 5000, with men being more commonly affected than women. “Arrhythmogenic cardiomyopathy leads to arrhythmia with a loss of cardiac muscle cells, deposits of connective tissue and fat within the cardiac muscle. This can cause sudden cardiac death, often during exercise,” says Volker Spindler, anatomist and head of the Cell Adhesion group at the University of Basel’s Department of Biomedicine.

Today, a range of gene mutations are known to trigger the condition. However, even with an early diagnosis there is no cure, only options for the management of symptoms are available. “Patients are advised to avoid any competitive or endurance sports and have to take medications such as beta blockers. Where appropriate, a catheter ablation may be performed or an implantable defibrillator may be used” says the cardiologist Gabriela Kuster, who heads the Myocardial Research group at the Department of Biomedicine. Sometimes the only option is a heart transplant.

Cardiac muscle cells become less ‘sticky’

The starting point for the project was the notion that many of the mutations affect structures known as the desmosomes. These are protein clusters on the surface of cardiac muscle cells that ensure a tight connection between the cells. “You can imagine these clusters to act like a piece of Velcro,” says the physician Dr Camilla Schinner, first author of the study. This led to the theory that the mutations reduce adhesion between the cells, thus weakening the cardiac muscle.

To test this hypothesis, Spindler’s team introduced a mutation similar to that found in patients into the genome of mice. The cardiac function of these animals was then examined by Kuster’s group. The result: the genetically modified animals showed a heart disease with arrhythmia that resembled arrhythmogenic cardiomyopathy in humans. In addition, microscopic and biochemical analysis indeed showed reduced adhesion between the cardiac muscle cells. The researchers also observed the scarring of the cardiac muscle typical for this disease.

Preventing cardiac tissue damage

Their next step was to investigate how diseased cardiac muscle differed from healthy conditions at the molecular level. Mice with the mutation showed an increased amount of a particular protein at the Velcro-like structures of the heart muscle cells. This leads, via a series of events, to connective tissue deposition and scarring of the heart. The addition of a substance which blocks this cascade prevented disease progression – which is why Spindler here sees a potential new treatment approach.

“Nevertheless, there is still a long way to go until an application in humans may be considered,” he points out. “But we now have better options to study the disease in more detail to improve our understanding of the underlying mechanisms.”

Source: University of Basel

Categories : Cardiovascular DiseaseTags :

Worse Lung Function Linked to Sudden Cardiac Death

On By ModernMedia
Photo by Camilo Jimenez on Unsplash

A new study found that people with modest but measurably worse lung function are more likely to suffer sudden cardiac death (SCD).

SCD is death due to a cardiovascular cause that occurs within one hour of the onset of symptoms. A sudden cardiac arrest occurs when the heart stops beating or is not beating sufficiently to maintain perfusion and life. There are often no previous warning signs, and is thought to be responsible for around 20% of all deaths in Europe.

The study was presented at the ERS International Congress by Dr Suneela Zaigham of Lund University. She said: “Although sudden cardiac deaths are common, we don’t know enough about who is at risk in the general population. There are links between lung and heart health, so we wanted to investigate whether measurable differences in lung function could offer clues about the risk of sudden cardiac death.”

The study involved 28 584 middle-aged participants with no known heart problems. All took part in spirometry tests where they were asked to blow into a machine to measure how well their lungs were working. Over the following approximately 40 years, researchers recorded any SCDs (death on the day of a coronary event) or any non-fatal coronary events (coronary events where people survived the first 24 hours)

They found that measurably lower lung function in middle-aged people (one standard deviation lower in the amount of air they could blow out in one second, which equates to around 0.8 litres) was more strongly associated with suffering a SCD (a 23% increase in risk) than a non-fatal coronary event (an 8% increase in risk) later on in life. The pattern of risk remained even in people who had never smoked.

Dr Zaigham said: “We believe this is the first study to directly compare the risk of sudden cardiac death and non-fatal coronary events and their links with lung function in the general population.

“Our findings suggest that testing people’s lungs when they are middle-aged and healthy could help spot those who have a higher risk of sudden cardiac death. This could enable people to take steps to potentially reduce the risk of this devastating event.”

A limitation of the study is that risk questionnaires were administered at the start of the study and these factors could have changed. The researchers next seek to see whether SCD could be prevented by testing lung function as part of current cardiovascular risk assessment. They plan to explore the link between lung function and SCD further to see if heart abnormalities, variable blood pressure or genetic causes are involved.

Source: European Respiratory Society