Sudden Cardiac Death

Sudden cardiac death is the sudden and unexpected death of a person due to a sudden cardiac arrest or electrical disturbance of the heart.

The most common cause of sudden cardiac death in older people is coronary artery disease and in people under 35 it is more likely to be from an inherited heart condition. However, between 45 and 50% of sudden cardiac arrests occur in people with no known heart disease, making it a major public health problem. It accounts for approximately 4.25 million deaths worldwide each year. Official mortality census reports indicate that sudden cardiac death claims 450,000 victims per year in the USA, 10 times as many people who die from road traffic accidents in the European Union and US combined[1].

While a heart attack occurs when there is a blockage to in an artery to the heart which prevents sufficient blood-rich oxygen reaching the heart muscle and it becomes damaged, a sudden cardiac arrest occurs when the electrical functionality of the heart malfunctions and becomes irregular. When this happens, a person is likely to die unless they receive immediate treatment and the current survival rate for someone who experiences a cardiac arrest outside of hospital is only around 10%.

[1] Wellens HJJ et al. Risk stratification for sudden cardiac death: current status and challenges for the future. Eur Heart J 2014;35:1642-1651 (doi:10.1093/eurheartj/ehu176).

Magnetocardiography and sudden cardiac death

Magnetocardiography (MCG) has the potential to play a large role helping researchers, and ultimately medical and healthcare professionals, to better understand sudden cardiac death. While further research is required, initial indications suggest that MCG could:

  • Support with risk stratification, becoming one of the factors in the clinical risk evaluation and helping to identify those people most at risk of coronary artery disease;
  • Become part of a screening test for relatives of people who have died from unexplained death syndrome and sudden arrhythmic death syndrome;
  • Help to identify appropriate recipients for implantable cardioverter defibrillators;
  • Combine with structural imaging techniques, such as echocardiography, CMR, with 3-D representations of the MCG magnetic field map, as an enhancement to catheter ablation therapies.