Heart Attack: When Blood Stops Flowing to the Heart

A heart attack or myocardial infarction (MI) is a life-threatening emergency requiring immediate medical care. It happens when the blood flow to a section of the heart suddenly stops and the muscle cells do not receive enough oxygen. Usually, a heart attack is caused by a blockage of one or more coronary arteries. Without a blood supply, the heart cannot work properly. Cardiac function is reduced or even fails completely. In the latter case, death may occur suddenly. If only a small section of the heart’s muscle is affected, the heart may be injured but still able to function at a reduced capacity. The longer the heart’s blood circulation is disturbed, however, the higher the risk that muscle cells will die and be replaced by scar tissue. This scar tissue is not able to perform the tasks of the muscle and the heart will never regain its original power and capacity. Sometimes, scar tissue may cause irregular heartbeats because it cannot conduct the electrical impulses that control the heart’s activity. If the heart is severely damaged, even minor stresses may overstrain its capacity, causing a potentially fatal heart attack. It is therefore crucial to find and treat the blockage of the blood flow as quickly as possible.

Usually, a heart attack occurs suddenly and without any warning. The symptoms of a heart attack may vary from person to person. Women and men often experience very different symptoms. In about one-third of heart attacks, because contrary to common belief, a heart attack can also happen without causing significant symptoms. This “silent” myocardial infarction often occurs in people with diabetes. In many cases, it is detected randomly during an electrocardiogram examination. 

Symptoms may include: 

• Severe and long-lasting chest pain in men 
• Chest pain spreading to the arms, shoulder, jaw or upper abdomen 
• Cold sweats 
• Shortness of breath 
• Nausea 
• Fainting 
• Pain in the upper abdomen combined with nausea and vomiting (women) 

Since all heart attacks can be life-threatening or cause complications, always call emergency services if you suspect that you or someone near you is having a heart attack. 

The most important examination for quickly diagnosing a heart attack is the electrocardiogram (ECG). If the electrocardiogram findings confirm a heart attack, the heart’s electrical activity will be observed during emergency treatment in order to detect any heart rhythm disorders early. 
As a second step, the medical team has to find out where the affected section of the heart is and which coronary artery is blocked. To do this, they will perform echocardiography – an examination of the heart with ultrasound waves. Coronary arteries are usually examined via a catheter in a hospital’s catheterization laboratory. The medical team may also run blood tests, which indicate if a heart attack has occurred and how severe it was. Examinations like computed tomography or magnetic resonance imaging may provide additional information.