Heart attack

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The number of deaths caused by a heart attack is declining, partly due to good emergency care: since 1980, the number of infarct deaths has halved. Nevertheless, a heart attack was the second most frequent cause of death in Germany in 2015. Overall, men died more frequently than women. According to new studies, however, in the first year after a heart attack women have a 1.5 times higher risk of dying from the consequences of a heart attack than men. In general they suffer a heart attack less frequently than men.

Disease pattern

A heart attack, also called a myocardial infarction, occurs when the heart muscle is no longer sufficiently supplied with blood and oxygen. If blood circulation is not restored within a few hours, part of the heart muscle dies. Signs of a heart attack are severe chest pain lasting longer than 5 minutes, which often radiates to other regions, for example to the arms or upper abdomen. Sometimes the pain is perceived as a severe burning sensation. A violent feeling of tightness in the chest is also a typical sign of a heart attack. Other rather unspecific symptoms are nausea, vomiting or shortness of breath. Many patients also feel anxiety, accompanied by cold sweat and pallor.

Depending on where the infarct develops and how big it is, it has different effects. One complication are arrhythmias, which can develop into life-threatening ventricular arrhytmia and result in sudden cardiac arrest (cardiogenic shock). 40 percent of those affected die within the first day, almost half of them from cardiogenic shock.

In the long term, scarring of the heart muscle can lead to heart failure, particularly in the case of major heart attacks. Aneurysms or heart rupture, where the heart’s muscles, walls or valves split apart  (ventricular or septal rupture) as well as inflammations of the pericardium can also occur. Even years after a heart attack, the risk of life-threatening cardiac arrhythmias including sudden cardiac arrest is significantly increased. This is particularly true if the heart has been severely damaged and is unable to effectively pump blood around the body . In these cases, doctors implant a defibrillator, which emits electric shocks to stop the dangerous cardiac arrhythmias.

Causes

A heart attack occurs when one or more blood vessels of the heart (coronary arteries) are partially or completely blocked. Coronary artery disease, i.e. deposits in the coronary arteries, causes most heart attacks. The deposits on the vessel walls tear open, blood platelets accumulate at the side of he rupture and a blood clot forms, blocking the vessel. Other causes, such as a spasm of a coronary artery, are rather rare.

Therapy

A heart attack is an emergency. If chest pain is unclear, an emergency room should be consulted immediately. Especially older women should think about it and act accordingly. According to current study results, it takes the longest for them to get to an emergency room after the first signs. This means that valuable time is lost to limit the damage to the heart muscle. First, an electrocardiogram (ECG) is recorded in the emergency room. If this is not meaningful, the doctors analyse certain biomarkers in the patients' blood. The most important marker for a heart attack is troponin. If its value rises within three hours, it is sure to indicate a heart attack. In order to prevent further damage to the heart, doctors use a cardiac catheter to dilate the occluded arteries as quickly as possible and insert a stent. This vascular support is intended to keep the artery open long term.

If there is no cardiac catheter department in the receiving hospital, an intravenous administration of medication is given to dissolve the blood clots. The patient will then be transferred as quickly as possible to a cardiological centre with a cardiac catheter department. Even after discharge from hospital, patients still have to take medication. Regular check-ups are also necessary.

Clinical Studies in the DZHK

SMART-MI-DZHK9 – Implantable cardiac monitors in high-risk post-infarction patients with cardiac autonomic dysfunction
APPROACH-ACS-AF-DZHK7 – Apixaban versus Phenprocoumon: oral anticoagulation plus antiplatelet therapy in patients with acute coronary syndrome and atrial fibrillation