Investigated About 80 percent of cardiac infections go unrecognized - with serious consequences

Later dangers: About 80 percent of myocardial infarctions are not noticed
The results of a study are likely to cause concern. About 80 percent of all heart attacks remain unrecognized by those affected. In many cases, an infarct of the heart triggers little or no pain. A short dizziness, a little heartache and already the symptoms are forgotten. Many doctors also trivialize and do not recognize the heart attack. However, infarcted regions of the heart muscle may be left behind. This increases the risk of sudden cardiac death.

Much of the heart attacks go unnoticed
The so-called dumb infarction is apparently much more common than previously thought. According to a recent US study, nearly 80 percent of heart attacks go unnoticed and are not detected by ECG, the news agency dpa reports. As the researchers write about David Bluemke of the National Institutes of Health (NIH) in Bethesda, Maryland, the clinical significance of mute heart attacks is unclear. However, there are indications that the scarring they cause could contribute to sudden cardiac death. The scientists published their findings in the journal "Journal of the American Medical Association" (Jama). Professor Thomas Meinertz, Chairman of the German Heart Foundation, stated that the result obtained in the USA could probably also be transferred to Germany.

A heart attack is usually symptomatic in women differently than in men. Image: Robert Kneschke - fotolia

Damaged muscle tissue increases the risk of heart problems
On the occasion of the World Heart Day at the end of September, it was reported that, especially in women, heart trouble and heart attack are often not recognized. Health professionals are always keen to educate patients about how to quickly detect a heart attack. In an interview a few months ago, Professor med. Volker Klauss, a specialist in internal medicine and cardiology in Munich: "The classic signs, such as annihilating chest pain radiating to the arms, the upper abdomen, in the back or in the neck or jaw, women feel significantly less compared to men frequently. They tend to have nonspecific symptoms such as severe shortness of breath, nausea, or vomiting. "Those affected should also know about the consequences. In survivors of a heart attack, the damaged muscle tissue is replaced by scar tissue, which can no longer contract. This is considered a risk factor for future heart problems. In their study, the doctors around Bluemke now wanted to determine how many heart attacks in the US population go undetected.

Scarred heart tissue not noticed on ECG examinations
To find out, they examined 1,840 people aged 45 to 84 who had no heart disease at baseline. Ten years later, they then used cardiac magnetic resonance imaging (CMR) to check for scarred heart tissue. At this time the participants were on average 68 years old. As the researchers report, they found in 146 subjects, so close to eight percent, scar tissue on the heart muscle. Only 32 of them had previously been diagnosed with an infarct. In contrast, in 78 percent of those affected, he had gone unnoticed and also later not noticed in ECG examinations. Infarcts were reported to be about five times more common in males than females. In addition, people with obesity and smokers were particularly at risk.

Numbers in Germany could be even higher
"The clinical significance of undetected scarring of the heart muscle remains to be seen," report the study authors. "However, in more than 70 percent of patients with sudden cardiac death but no known coronary artery disease, previous scars on the myocardium were found in pathological examinations. We need more studies to understand the clinical consequences of such undiscovered scars. "

The cardiologist Meinertz was not surprised by the result: "The heart muscle scars demonstrated in this work are probably the result of dumb heart attacks. Clinically it has long been known that heart attacks can proceed with virtually no symptoms, "said the physician. "What clinical significance these scars have is not known. This can only be clarified by continuing to observe the participants of the study in the long term. "Professor Heribert Schunkert of the German Heart Center Munich emphasized, however, that the results of the very accurate study are remarkable in this clarity. He even suggested that mute heart attacks could be more common in Germany than in the US, as risk factors such as hypertension are more prevalent in Germany. (Sb)