The patients also faced a higher risk shortly after coming down with other respiratory infections, the findings showed.
"People at risk of heart disease should take precautions to prevent respiratory infections, and especially influenza, through measures including vaccinations and handwashing".
The researchers found that the risk of heart attacks was somewhat higher for adults over the age of 65, and for patients who were infected with an influenza B strain of the flu, rather than influenza A.
Previous studies have looked for - and found - increased rates of heart attacks during influenza season.
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In Bethlehem, the city's Catholic Mayor Anton Salman said Pence's comments contradict his declared aim of helping Christians in the Middle East.
"We know that influenza vaccines aren't 100% effective", he added.
"You should look at the yearly flu shot that way, too", said Kwong, a scientist at the Institute for Clinical Evaluative Sciences, in Toronto.
According to the study, the heart attack rate was 20 admissions per week seven days after a flu diagnosis, compared to only 3.3 heart attack admissions a week in the year before and after a flu diagnosis. "All of these can increase the chance of having a heart attack", Dr Kwong said.
Philippa Hobson, senior cardiac nurse at the British Heart Foundation said: 'There is evidence that heart attacks happen more often during or immediately after an acute inflammatory illness such as flu.
The researchers worked out that patients were six times more likely to have a heart attack if they had been diagnosed with the flu a week earlier.
The researchers cautioned that the people in their study were not suffering from mild flu symptoms.
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However, he insisted that "it is important that we do that in parallel and don't vitiate the fundamentals of the Iran nuclear deal".
Flu has cause inflammation of the heart, brain or muscle tissues; and multiple organ failure.
Dr. Kwong explains that there are several ways that a respiratory infection like the flu can lead to a heart attack. For 76%, it was their first heart attack, technically known as an acute myocardial infarction.
A bad case of the flu can trigger a short-lived, but substantial, spike in some people's heart attack risk, new research suggests.
'Getting the flu shot can help prevent the flu and reduce the intensity of the illness if one comes down with it - highly recommended to anyone without a contraindication to receive it!' Dr Brian Secemsky, an internist at One Medical in San Francisco, told Daily Mail Online.
"If someone does have the flu, unfortunately there is no cure, but patients can assist their own recovery through taking plenty of rest and drinking lots of fluids as it is easy to become dehydrated". Many of them had risk factors for heart attack, such as diabetes, high blood pressure and high cholesterol.
"All adults should get a flu vaccine, especially people who are susceptible to getting sick", Blaha said.
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It was compiled at the request of the US Congress , amid a growing worldwide debate over whether e-cigarettes are safe or harmful. For young people and those who do not smoke, the message would be to not use electronic cigarettes.
"The best prevention for flu, other than observing good hygienic practices, such as regular hand washing, is for people, particularly those in at-risk groups, including patients with long-term conditions and pregnant women, to get their flu jab".