Category: Orthopedics
Keywords: Marathon, cardiac arrest, cardiac death (PubMed Search)
Posted: 10/13/2012 by Brian Corwell, MD
(Updated: 11/22/2024)
Click here to contact Brian Corwell, MD
Congratulations to today's Baltimore marathoners and the medical race staff
In honor of them:
Marathons are becoming increasingly popular with participation rising from an estimated 143,000 US marathon finishers in 1980 to a record high of 507,000 during 2010.
Most victims of exercise-related sudden cardiac arrest have NO premonitory symptoms
Autopsy reports show that
1) 65 - 70% of all adult sudden cardiac deaths are attributable to coronary artery disease.
2) 10% due to other structural heart diseases (HOCM, congenital artery abnormalities)
3) 5 - 10% due to primary cardiac conduction disorders (prolonged QT, ion channel disorders)
4) Remainder are due to non cardiac etiologies
Overall risk of sudden cardiac arrest is approximately from 1 in 57,000 and the risk of sudden cardiac death is approximately 1 in 171,000. Mortality without intervention after sudden cardiac arrest is greater than 95%. The majority occur in middle to late aged males.
V fib/V tach are the most common arrhythmias leading to sudden cardiac arrest. Most events occur in the last 4 miles of the racecourse.
Survival decreases by 7 - 10% with each minute of delayed defibrillation. Defibrillation within 3 minutes can produce survival rates as high as 67 - 74%. After 8 minutes, there is a dramatic decrease in survival. Prompt CPR increases survival from 2.5% to greater than 8%.
Sudden cardiac arrest and death in united states marathons. Webner D, Duprey KM, Drezner JA, Cronholm P, Roberts WO. Med Sci Sports Exerc. 2012 Oct;44(10):1843-5.
