Heart Disease – A Guide To The Commonly Asked Jargon

In Articles, Phil Says by Philip Yiin

We get a lot of questions about heart disease and the first step is often untangling what exactly each word means. Especially if they’ve been doing a lot of reading online but even if they’ve been seeing a cardiologist, either the cardiologists hasn’t taken the time to explain what’s going on properly or the patient doesn’t remember or wasn’t paying attention. Either way, this is the first step – making sure everyone is on the same page when we use the words below:

Acute Myocardial Infarction

This is what most people recognise as a heart attack; imagine someone suffering from cold sweats, cold and clammy hands and legs, giddiness, fainting, crushing chest pain that can be referred to the left arm and neck and vomiting. An infarction refers to when a part of the heart tissue is damaged or may even be dead due to the total blockage of a coronary artery. There are also SILENT HEART ATTACKS that present with similar symptoms but without any chest pain


Angina refers to chest pain because of the narrowing of coronary arteries (see below) and the resulting lack of blood supply to the muscle of the heart. When a patient can predict the chest pains after a specific amount of physical exertion and recovers quickly after taking glyceryl trinitrate tablet or resting, then this is known as STABLE ANGINA. 

When a patient cannot predict the chest pain (ie. the the angina comes and goes at anytime irrespective of exertion) this is known as UNSTABLE ANGINA. This is of greater concern than the former.

Coronary Arteries

Coronary arteries are small blood vessels that are about 1.5mm to 3.5mm in diameter and are responsible for supplying blood to heart muscle. There are usually right and left coronary arteries – the left artery branches into two so everybody has three branches of coronary arteries.

Congestive Heart Failure

When a patient’s heart is so weak it is unable to pump blood anymore and propel it to the rest of the body, then this is known as congestive heart failure. Congestive heart failure often occurs due to a coronary artery disease or an prior infarct. Ischemia (an inadequate blood supply to an organ or part of the body, especially the heart muscles) leads to the heart muscle becoming weaker and weaker. What happens is blood builds up in the veins and body tissue. The congestion of this fluid compounds to the problem and makes it even harder for the heart to keep pumping.

Signs you might recognise include:

  1. Swelling in the lower extremities such as the legs, ankles and abdomen – you may observe this is as red rings around your legs or ankles where they push up against shoes, anklets and other such things.
  2. Difficult sleeping
  3. Sudden weight gain from the fluid retention
  4. Wheezing or dry hacking cough
  5. Fatigue
  6. Heart palpitations or chest pain
  7. Confusion
  8. Irritability
  9. Difficulty breathing
  10. Reduced urine output

Fluid may accumulate in the lungs (this is called a PLEURAL EFFUSION or PULMONARY OEDEMA) and the patient may have difficult lying down to sleep. The temporary solution is to use high pillows. In some cases, the patient may wake up frequently in the middle of the night with shortness of breath.

Be aware that some of these symptoms require immediate medical attention especially if you see any coughing out blood, frothing at the mouth or sudden shortness of breath.

Special Entry: Cardiac X Syndrome

What happens if you have chest pain but possess patent and perfectly functioning coronary arteries? This is sometimes known as cardiac x syndrome. The problem might be with the microcirculation (ie. the capillaries, the smallest blood vessels) that can only be observed under a microscopy. When these capillaries become blocked (via intravascular coagulation) due to a spasm of the arteries or the viscosity of the blood itself. This can’t be tested for by your typical methods – a microscope has to be used to check the capillaries in the eyes and at the base of the nails. Acidity of the blood is also thought to contribute to this and testing for carbon dioxide and bicarbonate levels can be done in a hospital to assess this.