Complications of Diabetes

Information on Heart Attacks (myocardial infarction) for people who have Diabetes


Having a heart attack is a life changing experience. This leaflet deals with some of the questions you may have.

What is a heart attack / myocardial infarction?

The heart is a pump made of muscle, which is supplied by a meshwork of tiny blood vessels. The main blood vessels of the body, the aorta feeds these blood vessels via two main coronary arteries the right and left coronary artery.

Atheroma or atherosclerosis is a process which causes build up of fatty deposits in the wall of blood vessels. These vessels become ‘furred-up’ over a period of time, usually several decades. The process leads to narrowing of the arteries. If a vessel becomes completely blocked due to a blood clot, the muscle it supplies is deprived of oxygen and essential nutritients. This results in death of a part of heart muscle. This injury to heart muscle is called a heart attack or myocardial infarct.

How will I know I am having a heart attack?

Chest pain is a prominent feature of a myocardial infarction. This may range from a crushing central chest pain, associated with nausea, sweating and feeling ill to a feeling of pressure or heaviness. Other associated symptoms include shortness of breath. The pain may extend to the jaw, shoulder or on or both arms.

The pain during a heart attack, is often accompanied by deep unease or anxiety. You may feel you are about to die and are no longer in control. Many patients who have had a heart attack describe the pain as the worst they have ever had. Even lesser degrees of pain or discomfort should not be ignored. If you think you may be having a heart attack, seek help immediately as early treatment prevents further damage to heart muscle.

I already have angina – what’s the difference?

Angina is a form of chest pain which arises due to similar reasons except damage or injury to heart muscle does not occur. The pain resolves with rest or sublingual GTN and does not usually last longer than half an hour.

What should I do?

Call for an ambulance by dialling 999 in the UK.

Chew a tablet of aspirin if you are not already taking aspirin, unless you are allergic to aspirin.

What happens in hospital?

Once in hospital you will have an electrocardiogram (ECG) recorded. This is a recording of electrical activity of the heart which helps doctors diagnose a heart attack.

If a heart attack is diagnosed on ECG, things will happen very rapidly. This is intended to treat you as quickly as possible so as to prevent further damage to your heart. You may find this experience frightening.

It is also likely that you would be rushed on to a coronary care unit as an emergency. Staff may rapidly ask you essential questions to help decide your treatment. A doctor or nurse will insert an intravenous cannula into your arm which is used for administering drugs. You may be given an oxygen mask.

Why all the fuss?

When you are having a heart attack ‘time is heart muscle’. It is most important that you seek help early. Timely treatment can mean all the difference in enjoying a good quality of life after a heart attack.

What’s special about coronary care units?

Coronary Care Units (CCUs) are a type of intensive care ward for the management of people with heart problems. These units have a small number of beds which allows specially trained nursing staff to devote close attention to you.

Staff on CCU are specially trained to deal with cardiac emergencies and have special equipment for monitoring the heart and treatment such as ‘cardiac pacing’ for rhythm disturbances.

You may find CCU daunting due to all the monitoring equipment and the ocasional bursts of activity surrounding patients who require urgent attention.

What are ‘clot-busting’ drugs (thrombolytic agents)?

Thrombolytic drugs are sometimes used in the early hours of a myocardial infarct to dissolve a clot which is lodged somewhere in the coronary arteries. These work best when given as early as possible, which is why you are ‘rushed through the system’ to CCU.

What are the risks associated with thrombolysis?

The main risk of thrombolytic treatment relates to bleeding complications, mainly stroke and gastro-intestinal bleeding. Allergic reactions may cause a drop in blood pressure.

Who should not have thrombolysis?

There are certain reasons why your doctors may decide not to give you thrombolytic treatment. Some of these reasons are listed below:

  • recent stroke
  • if you are taking warfarin
  • recent surgery
  • a recent gastro-intestinal bleed

What complications may arise from a heart attack?

The heart may develop abnormalities of rhythm control resulting in a very fast or very slow heart rate.

Heart failure may cause accumulation of fluid in the lungs called ‘pulmonary oedema’. Blood pressure may fall due to pump failure.

What is the impact of this heart attack on my diabetes?

Having a heart attack causes release of stress hormones which increase your blood sugar concentrations. Many patients with diabetes require a continuous insulin infusion using a ‘sliding scale’ for control.

Diabetes increases your risk of having a heart attack. The risk of complications following a heart attack is also higher in people with diabetes.

What happens on discharge from CCU?

This is dealt with in a separate leaflet called ‘Life after a heart attack.


Dr Nishan Wijenaike, MD FRCP
Consultant Diabetologist
Original article November 2003
Updated November 2007