What is a Heart Attack?

Our heart is the most important organ in the human body as this organ pumps relentlessly from the day that we are born and doesn’t stop beating even when we are asleep. In fact, our heart pumps about a million barrels of blood in an average lifespan. Therefore, the heart is like the engine of the human body. If anything goes wrong with the heart, all the other organs will also be affected.

The prevalence of heart disease in Malaysia is ever increasing. What used to be a disease of the elderly is now seen much earlier. Nowadays, Malaysians in their 20’s and 30’s are suffering from heart attacks. Heart disease is still the number 1 killer in Malaysia. Almost 1 in every 4 deaths is caused by heart disease. On average, about 140 persons for every 100,000 people will suffer from a heart attack during their lifetime.

The risk factor for heart disease can be divided into non-modifiable and modifiable risk factors. The non-modifiable risk factors are age, sex and family history. The modifiable risk factors are namely diabetes, hypertension, smoking, hyperlipidaemia and obesity.

The typical symptoms of a heart attack are left sided or central chest pain, nausea, sweating, left arm pain and jaw pain. However, some patients like those with diabetes may not have chest pain and only have difficulties in breathing. Women are another group that often doesn’t have the typical symptoms, and they often present with epigastric pain.

What actually happens during a heart attack? Our heart has 3 main blood vessels that supply blood to the heart muscle with a diameter between 2.5 to 4mm. A diseased blood vessel can slowly get narrowed over time due to atherosclerosis. In an acute myocardial infarction, the atherosclerotic plaque ruptures and the blood that normally flows within the lumen of the blood vessel is exposed to the lipid rich contents of the atherosclerotic plaque. This causes the blood to form a clot and thus occludes the flow of blood within the blood vessel. Once this happens, the heart muscle cells will start to die and the heart will become weaker until it finally fails to pump blood.