Men and women show different signs before arrest

During the hours before an acute cardiac arrest, the body produces warning signals that seem to vary considerably between men and women.

Every minute, your heart pumps some 5 litres of oxygenrich blood to every inch of your body; it happens without you realising it. But even in young and seemingly healthy people, this hard-working muscle can stop – suddenly and unexpectedly. It happens to millions of people worldwide every year, and in 90% of cases, it is fatal.

Acute cardiac arrest, then, is a global health problem that doctors and researchers are working hard to understand and combat, and early warning signs are a key area of research. Researchers from the Schmidt Heart Institute in the US have recently published a study which shows that the body often gives small warning signals during the 24 hours before the heart stops. Interestingly these small signs seem to be very different between men and women.

The researchers behind the study used data from two different cardiac arrest studies: one was conducted in multi-ethnic communities of Ventura County, California, while the other took place in Portland, Oregon.

The participants of the studies were people between the ages of 18 and 85 who suffered an unexpected cardiac arrest that was witnessed either by a bystander or attending emergency personnel.

Going through the data, the researchers analysed both individual symptoms and groups of symptoms leading up to the moment that the heartbeat stopped. They compared these results with those of a control group who had experienced similar symptoms and had called an ambulance, but without having an actual cardiac arrest.

The researchers’ analyses showed that 50% of the 823 people with sudden cardiac arrest experienced at least one revealing symptom up to 24 hours before their heart stopped. The most common symptom was shortness of breath, experienced by 41% of participants during the 24 hours before the cardiac arrest. Some 33% experienced chest pain, 12% increased their sweating, and 11% experienced what the researchers refer to as seizure-like activity.

But while men experienced the shortness of breath, chest pain and sweating leading up to cardiac arrest, the experience was markedly different for women, with only shortness of breath seeming to be have a strong association with cardiac arrest.

The researchers hope that the different warning signals in men and women will make us better at predicting and preventing some of these incidents before they occur.