Cardiac Arrest Explained
Granted, most distance runners, especially those in their 20s and 30s, are not what springs to mind when you think of heart disease. But among those who die in races, the disease is often underlying, a result of a congenital abnormality that often goes undetected until it's too late.
"The most common abnormality [among runners under 35] is known as hypertrophic cardiomyopathy (HCM), or a thickening of the muscle wall around the heart," explains Campbell. "As we run, the blood flow is limited from its exit from the heart to the body."
Runners with hypertrophic hearts are also at risk for ventricular tachycardia, a deadly, irregular heartbeat. Combined with the exertion of running, as well as outside factors like extreme cold or heat that can place additional stress of the circulatory system and heart, HCM can kill even the most fit runners with little warning.
More: The Heart of the Matter
What about cardiac arrest among runners over the age of 35? Heart attacks from coronary artery disease are the typical triggers.
"As we run, our heart muscle requires more oxygen and nutrients to perform," says Campbell. "If the demand exceeds the supply, as in the case of a blocked heart artery where not enough nutrients can get to the heart muscle, it can progress to a complete blockage of the heart artery, resulting in a heart attack."
A recent article published in the New York Daily News recommended that runners take a baby aspirin on race day for 10K and longer distances to help prevent heart attacks; however, Campbell only advises patients with known heart disease or previous cardiac arrest events to use aspirin as a preventative measure.
"Aspirin has never been proven to prevent a first heart attack or cardiac arrest," says Campbell.
