In a heart attack, a coronary artery becomes blocked, usually by a blood clot at a point already narrowed by deposits. The heart muscle beyond it no longer receives oxygen and is damaged – the longer the blockage lasts, the more so. The ground is almost always prepared by coronary heart disease, promoted by high blood pressure, smoking, diabetes, raised blood lipids, excess weight, lack of exercise and a family predisposition.
Typical signs are pressure, tightness or burning behind the breastbone that lasts longer than five minutes and can spread to the arms, neck, jaw, back or upper abdomen. Shortness of breath, nausea, cold sweat and restlessness often occur as well. Anyone who notices such signs should call 112.
In heart failure – medically also called cardiac insufficiency – the heart no longer pumps enough blood around the body. Common causes are coronary heart disease or a previous heart attack, long-standing high blood pressure, heart valve disease, inflammation of the heart muscle or arrhythmias. It usually develops gradually: you can manage less, you become short of breath during exertion or when lying down, your ankles and legs swell, and your weight rises due to retained fluid.
Heart failure becomes acute when it worsens rapidly, for example due to an infection, a new arrhythmia, a heart attack or forgotten medication. Fluid then builds up in the lungs, and breathing becomes difficult even at rest. In both emergencies, the priority is to relieve the heart and find the cause. In a heart attack, the blocked vessel should be reopened as quickly as possible, as a rule by cardiac catheter at a centre with a cardiac catheter lab.