Dr Mosterd reported, "although physical activity is the best way to promote cardiovascular health, exercise can also trigger an acute cardiac event leading to death. These dramatic and often high profile events, for example in soccer players, invariably lead to concerns and cast a shadow over the overwhelmingly positive effects of regular exercise."
ARREST is a database of all resuscitation attempts that have been performed in the metropolitan area of Amsterdam, which covers a population of approximately 2.4 million people. In the Netherlands, people dial 112 for medical emergency services, where an operator puts the caller in contact with a regional ambulance dispatch hub. If the dispatch center suspects it is a case of cardiac arrest, two ambulances of a single tier are sent out.
An AED (automated external defibrillator) used in CPR training
The research team gathered data from ARREST to find out how frequent exercise-related cardiac arrests were in the Amsterdam metropolitan area from 2006 to 2009. They also wanted to determine what the outcomes were for people with sports-related cardiac arrests.
They found that there were 48 out-of-hospital sports related cardiac arrests each year, equivalent to 5.8% of the total number of cardiac arrests that occur out-of-hospital.
From 2006 to 2009, in the Amsterdam metropolitan area:
- 145 out of a total of 2,517 OHCAs (out-of-hospital cardiac arrests) were experienced by people who had been doing some kind of exercise during the cardiac arrest, or up to 60 minutes before it occured.
- 49 had been cycling
- 22 had been playing tennis
- 16 had been at the gym
- 13 had been swimming
- Of the 145 cases, ten were female
- 7 (inc. 1 female) of the 145 cases were aged no more than 35 years
- 65 of the 145 cases survived the event
- People with an exercise-related OHCA were found to have a 45% chance of surviving the event
- People with a non-exercise OHCA had a 15% chance of surviving the event
According to the data gathered, 45% of people who suffered a cardiac arrest whilst exercising survived.
"Patients persons suffering an exercise related OHCA are three times more likely to survive the event than persons whose arrest is not exercise related. None of the survivors of exercise related OHCA suffered serious neurologic damage, which was not the case for those surviving a non exercise related OHCA."
Exercise-related OHCAs occur in more younger people than non-exercise related ones, the researchers added.
99.3% of exercise-related OHCAs occurred in public places, compared to 24.3% of non-exercise related ones. This also makes it much more likely that the sports-related ones are seen and acted upon by bystanders. 86.2% of sports-related cases received bystander CPR (cardiopulmonary resuscitation), compared to 64.4% of non-sports related ones, while 35% of sports-related cases were administered shocks using automated external defibrillators, compared to 22.2% in non-sports related ones.
Dr Mosterd said:
"The remarkably good survival of victims of exercise related out-of-hospital cardiac arrest can partially be ascribed to the fact that they are younger and more likely to suffer the arrest in a public location, leading to bystander cardiopulmonary resuscitation, often with the use of an automated external defibrillator. Taking these factors into account exercise per se also contributes to a better outcome."
There is only one other study that has compared exercise-related OHCAs with those in the general population, the team explained; it was carried out in France.
Dr Mosterd said:
"The survival rate to hospital discharge of exercise related OHCA victims was three times higher in our study group than was observed in the French study (45% vs 16%). As most exercise related events are bystander witnessed (89% in the Netherlands vs 93% in France) the most likely explanation for the remarkably better survival in the Netherlands relates to the high rate of initiation of bystander CPR (86%) compared to 31% in France. It is of note that the highest survival rates (around 50%) in France are found in two regions where bystanders initiated CPR in 90% of cases (compared to 86% in our population).
More research is needed to determine why, after taking into account favourable factors such as age, location of the event and initiation of CPR, persons who exercise during or shortly before having a cardiac arrest still have a better prognosis than people who have a cardiac arrest that is unrelated to exercise. The number of exercise related out-of-hospital cardiac arrests in the general population is low, particularly in women and in those aged 35 years or younger. We demonstrated for the first time that cardiac arrests occurring during or shortly after exercise carry a markedly better prognosis (45% survival) than cardiac arrests that are not exercise related (15% survival)."
Dr Mosterd added that timely bystander CPR efforts with AED usage are probably crucial for improving survival rates in people with non-hospital cardiac arrests. He believes their findings should have "direct implications for public health programs aimed at preventing exercise related sudden death."
What is sudden cardiac arrest?Sudden cardiac arrest, also known as circulatory arrest or cardiopulmonary arrest, occurs when the heart stops working, the patient stops breathing and loses consciousness. It usually happens when something goes wrong with the electrical signals in the heart that undermines its pumping action, resulting in the loss of blood flow. In most cases, the heart simply stops.
Cardiac arrest is a medical emergency.
Cardiac arrest is not the same as a heart attack:
- A heart attack or myocardial infarction occurs when one of the arteries that supplies blood to the heart muscle, the coronary artery, has a sudden blockage that stops the blood supply to a portion of the heart muscle - that part of the heart muscle dies. Put simply, a heart attack is the death of a portion of the heart muscle.
- A cardiac arrest is caused by a sudden heartbeat irregularity (arrhythmia), called ventricular fibrillation. The electrical signals within the heart degenerate to total chaos, and it stops beating. Put simply, a cardiac arrest is when the heart stops because of an electrical fault. Without emergency medical help the patient nearly always dies.
The only treatment that can get the heart moving again is to deliver a large electrical shock to the heart with a defibrillator - the shocks "reboot" the heart, so that normal heart rhythm may be restored.
Written by Christian Nordqvist