Preventing sudden cardiac death

IT IS not uncommon to read about people who were apparently in the pink of health who passed away suddenly in their sleep. This is almost always due to sudden cardiac arrest (SCA), a condition in which the heart stops pumping effectively as a result of a life-threatening heart rhythm. Death due to a cardiovascular cause that occurs within an hour of the onset of the cardiovascular event is termed sudden cardiac death (SCD).

The annual incidence of SCA based on data from the United States and European studies ranges from 0.04 per cent to 0.1 per cent of the population. In the US, the median age of SCA is between 66 and 68 years, and males are more likely than females to develop SCA.

For a long time, it has been thought that the main mechanism of SCA was a life threatening arrhythmia such as ventricular fibrillation (VF) or ventricular tachycardia (VT). Both sustained VT or VF are abnormal heart rhythms originating from lower heart chambers that prevent the transmission of electrical signals from the “generator” or pacemaker sited in the upper right heart chamber.