14 DAY TRIAL // Although you might think that a heart attack is something you would notice if it happened to you, a team of Dutch researchers who assessed over 4,000 men and women over 55 to see how many heart attacks went undiagnosed at the time they occurred, found that the figure was more than four in 10.
The authors, from the Department of Epidemiology & Biostatistics at Erasmus Medical Centre in Rotterdam, say their findings suggest that the role of ECGs in existing cardiovascular prevention programs should be evaluated.
The results come from an analysis of a large proportion of the men and women involved in the Rotterdam Study, a prospective population study investigating chronic disabling diseases. A total of 5,148 participants with no evidence of prevalent myocardial infarction (MI) were enrolled from 1990-93.
They underwent a baseline ECG and examination. Data from clinically recognized MIs (i.e. heart attacks that were formally diagnosed) over the years that followed were analyzed. The 4,187 of the total who had at least one repeat ECG during two rounds of follow up assessment between 1993-96 and 1997-99, were analyzed for clinically unrecognized MI (heart attacks not diagnosed at the time of occurrence).
"Overall, 43% of the total heart attacks had been clinically unrecognized, a third of the male heart attacks and more than a half of the female heart attacks. This is a significant proportion of all the MIs," senior author Dr Jacqueline Witteman said.
Dr Witteman said that in each of the age bands between 55 and 80, men had a higher incidence of recognized MIs than women and a similar incidence of unrecognized MIs. This provided the evidence that heart attacks are less often recognized in women, irrespective of characteristics that have previously been associated with MI.
According to co-author Dr Eric Boersma, Associate Professor of Clinical Cardiovascular Epidemiology, heart attacks may go unrecognized because of atypical symptoms, and the explanation for the worse figures for unrecognized heart attacks in women was not straightforward.
"There are likely to have been multiple factors. Men and women experience chest pain in different ways. MIs can occur without typical symptoms in women (also in people with diabetes and the elderly). They may sense shoulder pain instead of chest pain, they may think they have severe flu that is taken a long time to recover from, and those with an inferior-wall infarction may complain of stomach pain," he said.
Image credit: www.yourheart.org.uk