How stressful can an election campaign really be? Potentially life-threatening, researchers say, at least in the case of the 2016 US presidential election. The divisive campaign may have raised the risk of abnormal heart rhythms and worsened high blood pressure in people with underlying cardiovascular disease, two studies suggest. One study focused on nearly 2,500 people (mostly white, with an average age of about 71) with implanted cardiac devices in North Carolina, a swing state in the 2016 election that was subjected to fiercely negative political commercials and campaign events. Researchers examined the incidence of cardiac arrhythmias (too fast or too slow heartbeats or irregular heart rhythms) in a six-week period spanning before and after the election, and compared it with two six-week control periods June/July 2016 and October/November 2015. There was a 77% rise in the risk of cardiac arrhythmias during the election phase versus the control periods, even after accounting for factors including age and underlying medical conditions, according to the study published in the Journal of the American Heart Association. In particular there was an 82% rise in the incidence of atrial arrhythmias, an abnormal heart rhythm that begins in the heart’s upper chambers and can lead to blood clots, stroke and other complications. There was a 60% jump in the rate of ventricular arrhythmias, an abnormal heart rhythm involving the heart’s lower chambers that can lead to cardiac arrest. The study’s lead author, Dr Lindsey Rosman, an assistant professor of medicine at the University of North Carolina, said previous research had indicated that acute cardiovascular events tend to rise in the aftermath of events such as natural disasters and terrorist attacks. “But the direct link between a stressful political election and an increase in cardiac events hasn’t been established – until now.” The researchers also assessed whether the risk of arrhythmia differed by political party affiliation. Surprisingly, people who voted for the losing candidate, Hillary Clinton, did not experience a higher rate of arrhythmias compared with those who voted for the winner, Donald Trump. A separate study investigated changes in blood pressure among different ethnic groups. Readings from about 2,000 non-Hispanic white people, non-Hispanic people of colour, and Mexican Americans in the pre-election period (May to October 2016) were compared against 1,700 randomly selected participants from the three groups a year into the new presidency (November 2017 to April 2018.) The researchers found significant increases in blood pressure among black and Mexican American participants with hypertension, but no significant rises in people who did not already have hypertension (regardless of their ethnic background. The lead author, Dr Andrew Hwang, an assistant professor of clinical science at High Point University, North Carolina, said it was possible that the passage of time may have played a role in worsening blood pressure measures. “However, given that the 2016 US election was a major national event, we may be able to suspect that the election may have contributed, in part, to changes in blood pressure.”