Experts compared cardiovascular disease events in the days after 2016 election.
They were 1.62 times higher two days after election compared with week before.
Experts advise 'deep breathing' in the days following next month's US election.
Heart attacks and strokes soared by 62 per cent in California during the two days after President Donald Trump was elected four years ago, a new study claims.
US researchers say 'sociopolitical stress' may have been a trigger of cardiovascular disease events in the days following the election on November 8, 2016.
The figure is based on hospitalisation rates for acute cardiovascular disease events, including heart attacks and strokes, in a large southern California health system.
Experts now advise a programme of yoga, meditation and 'deep breathing' in the days following next month's US election if it delivers another shock.
The study comes the same day President and 2020 Republican candidate Donald Trump tweeted that the Democratic stronghold of California 'is going to hell'.
According to the Public Policy Institute of California, the 46.3 per cent of registered voters in the state are Democrats, compared with 24 per cent Republicans.
Voters in the state – both Democrat and Republican – are likely feeling the stress of another election campaign, according to the study authors.
'This is a wake-up call for every health professional that we need to pay greater attention to the ways in which stress linked to political campaigns, rhetoric and election outcomes can directly harm health,' said study author David Williams at Harvard Chan School.
The results, which were similar across sex, age, and race and ethnicity group, have been published in the Proceedings of National Academy of Sciences.
For the study, researchers analysed data collected by Kaiser Permanente Southern California, an integrated health system that provides care to 4.6 million people in the region.
They focused on diagnoses of acute myocardial infarction – the medical name for a heart attack – and stroke among adults, as well as emergency department diagnoses for chest pain and unstable angina.
Unstable angina is the condition where the heart doesn't get enough blood flow and oxygen, which may lead to a heart attack.
In the two days immediately after the 2016 presidential election, the rate of hospitalisations for CVD events was 573.14 per 100,000 person years (or 94 total hospitalisations), the experts say.
This compared with a rate of 353.75 per 100,000 person years (or 58 total hospitalisations) in the same two days of the week in the week prior to the election.
'In our diverse patient population that is reflective of Southern California as a whole, we saw that the risk of heart attacks increased after the 2016 election irrespective of sex, age, and racial-ethnic groups,' said study author Matthew Mefford at Kaiser Permanente Southern California.
'It is important that people are aware that stress can trigger changes in their health, and that health care providers help patients cope with stress by encouraging wellness strategies such as exercise, yoga, meditation, and deep breathing.'
Last week, the American Psychological Association (APA) reported that US adults consider the current political climate as a significant source of stress, according to the results of a survey.
Two thirds (68 per cent) surveyed said that the 2020 US presidential election is a significant source of stress in their life – an increase from 52 per cent during the 2016 presidential election campaign.
Adults with a chronic condition are consistently more likely than those who do not have a chronic condition to report the election as a source of stress in their life, the survey found.
And stress is also felt regardless of political affiliation – 76 per cent of Democrats said they felt significant stress, compared to 67 per cent of Republicans and 64 per cent of Independents.
While the proportion of black adults reporting the election as a source of stress jumped from 46 per cent in 2016 to 71 per cent this year.
'This has been a year unlike any other in living memory,” said Arthur C. Evans Jr., APA’s chief executive officer.
'Not only are we in the midst of a global pandemic that has killed more than 200,000 Americans, but we are also facing increasing division and hostility in the presidential election.
'Add to that racial turmoil in our cities, the unsteady economy and climate change that has fuelled widespread wildfires and other natural disasters.
'The result is an accumulation of stressors that are taking a physical and emotional toll on Americans.'
High levels of cortisol from long-term stress are thought to increase blood cholesterol, triglycerides, blood sugar and blood pressure – common risk factors for heart disease.
Previous research has shown that there is an increased risk of acute CVD events soon after earthquakes, industrial accidents, terror attacks and even sporting events.
In 2008, researchers reported a a 53 per cent increased incidence of cardiovascular health problems in the three years after the 9/11 terrorist attacks, brought on by stress.
Next month's US election on November 3 will determine whether Trump or Democratic presidential nominee Joe Biden will spend the next four years in the White House.
Biden is currently ahead of Trump in most national polls.
1. Breath deeply
Stress causes us to release the hormone noradrenaline, which makes us sweat, breath heavily and increases our heart rate.
Noradrenaline is sensitive to carbon dioxide and can therefore be controlled through breathing.
Professor Ian Robertson, author of 'The Stress Test', recommends we breathe slowly through our nose for five seconds and exhale for six.
2. 'Pose like a superhero'
Standing tall allows our lungs to fill up with air, improving our blood's oxygen supply and eliminating excessive production of the stress hormone cortisol.
Puffing out our chests also sends messages to the brain that we are confident and not in a stressful situation.
3. Clench your fist
Squeezing our fists is thought to help centre our thoughts, allowing us to pull on our inner strength.
Professor Robertson recommends you clench your right hand for 45 seconds, open it for 15, then shut it again.
4. Ditch coffee
It may feel essential, but your morning cup of coffee can cause insomnia, nervousness and a faster heart - which will only worsen feelings of stress.
Green tea contains less caffeine than coffee, as well as a specific compound, known as theanine, that boosts concentration and focuses the mind.
5. Eat breakfast
Skipping the most important meal of the day can cause low blood sugar levels, prompting our bodies to release cortisol to counterbalance this effect.
6. Stay hydrated
Carry a bottle of water with markings that prompt you to drink a certain amount by a specific time. Dehydration is a cause of stress in itself and leads to cortisol release.
7. Eat well
Vitamin C-rich foods including citrus fruits and berries boost the immune system, which is weakened by stress.
Snack on walnuts for an easily portable snack that is rich in magnesium to help calm the mind.
8. Get active
Exercise releases so-called 'feel good' hormones called endorphins that help to counterbalance anxiety.
And there is no need to take out an expensive gym membership. Brisk walking or skipping for five minutes a day can make a big difference to your stress levels.
9. Be mindful
Mindfulness if a form of meditation that focuses the mind on the present moment rather than reminiscing on the past or thinking ahead, which can both cause stress.
10. 'Fake it'
Common stress symptoms including a beating heart and lurching stomach also occur when we are excited.
Saying 'I'm excited' aloud can make all the difference.
Professor Robertson said: 'Fake it 'til you make it to trick your brain into creating a different emotion.'