Complications of coronary artery disease

Photo of an older man talking to a doctor (PantherMedia / luckybusiness)

Coronary artery disease (CAD, also called coronary heart disease, or CHD) is a condition in which the large blood vessels that supply the heart with oxygen have become narrower. This is caused by arteriosclerosis (hardening of the blood vessels). CAD can also lead to other types of heart disease.

The heart may perform more poorly, or your heartbeat may become irregular. The risk of a heart attack also increases.

Heart failure

Depending on which part of the heart is affected, heart failure can cause different problems: If the right half of the heart is affected, blood builds up in the veins that would normally transport blood from the organs and tissue back to the heart. The increased pressure inside the veins can push fluid out of the veins into surrounding tissue. This can cause edema (swelling) in the legs, and if heart failure is advanced, there may be edema in the abdomen or liver.

If heart failure affects the left side of the heart, blood will build up in the blood vessels that carry blood away from the lungs. This may cause shortness of breath, especially during more strenuous activities. Left-sided and right-sided heart failure sometimes occur simultaneously.

The severity of heart failure can vary quite a lot. There may be no or only mild symptoms, or it could have a major effect on your physical fitness. Possible symptoms include exhaustion, shortness of breath, chest pain and heart palpitations. Severe heart failure makes it difficult to perform normal tasks of everyday life, like walking up a few steps or taking a stroll.

Irregular heartbeat (arrhythmia)

If the heart isn’t getting enough oxygen, part of the heart tissue that regulates your heart rate may become damaged. This can cause the heart rate to become irregular, or the heart may beat faster or slower. These kinds of heart rhythm problems may cause a pounding or racing heart, tiredness or dizziness. Heart rhythm problems can be diagnosed with the help of an electrocardiogram (ECG). The most common type is atrial fibrillation

Heart rhythm problems may impair the pumping action of the heart, which can cause heart failure or make it worse. Some heart rhythm problems – especially atrial fibrillation – can result in blood clots forming in the heart. If they are pushed along by the flow of blood, they can cause a stroke if they reach the brain.

Heart attack

People have a heart attack if a coronary artery becomes completely blocked. The blockage stops part of the heart muscle from getting enough oxygen. If this goes on for too long, that part of the heart muscle can die and the situation becomes life-threatening. So immediate medical attention is needed.

The odds or surviving a heart attack have improved in recent years: In Germany, about 3 out of 4 people who have a heart attack will now survive.

Experts distinguish between two types of heart attacks:

  • ST segment elevation myocardial infarction (STEMI)
  • Non-ST segment elevation myocardial infarction (NSTEMI)

In STEMI, a certain part of the electrocardiogram graph, called the ST segment, is elevated. In NSTEMI, the ECG doesn’t show ST segment elevation.

A STEMI is usually treated using a cardiac catheter (angioplasty). This involves inserting a narrow catheter into the affected artery and gently pushing it along the artery to the narrowed passage. A balloon at the tip of the catheter can then be inflated using high-pressure air to widen the blood vessel. A tiny wire mesh tube called a stent is then usually implanted in the blood vessel to prevent it from becoming narrow again.

The treatment that is considered for NSTEMI or for unstable angina will depend on various factors, including how the symptoms develop over time, whether the person has other medical conditions, how old they are, and the risk of complications associated with the procedure. But most NSTEMIs are also treated with a cardiac catheter.