Chest Pain

With physical activity the heart beats harder and faster and needs more oxygen, but if a coronary artery has become narrowed, the blood and oxygen supply to the heart muscle is inadequate, creating chest discomfort (patients rarely describe it as a pain) in the form of a tightness and pressure in the chest, and sometimes breathlessness, symptoms which disappear as the activity ceases and the heart’s requirements for blood and oxygen diminish; this is what the term “angina” means.

There is a very stable and predictable pattern to the symptoms in such cases, for example, chest discomfort with walking uphill or walking quickly. It can also be more intense in the cold weather and with activity soon after eating a meal. Sometimes it is the first activity of the day that causes angina and subsequent activities are relatively unrestricted – this is known as “first effort” angina. Change in the pattern of angina, such as more frequent episodes, developing symptoms at a lower level of exertion, or experiencing symptoms at rest, requires urgent investigation as this is a sign that the blood supply to the heart is compromised, greatly increasing the risk of a heart attack.

Furring up of the arteries (atheroma) develops over many years and symptoms relating to this can occur both gradually and suddenly. Gradual progression of the furring up process typically causes angina; however, another manifestation of the same disease process is a myocardial infarction, commonly known as a heart attack. This typically occurs when an area of atheroma suddenly ruptures, exposing the undersurface of the artery lining and provoking an injury response, whereby a clot begins to form over the damaged area. If the clot is large enough it can block the artery entirely and this is the substrate for a heart attack.

In most cases this is unheralded and may well be the first indication that a patient has a heart problem, hence the importance of screening in medium and high risk populations. Sometimes a patient will have had angina symptoms which suddenly intensify such that chest discomfort develops with diminishing levels of exercise and is ultimately present at rest. Most survivors describe a heart attack as an intense discomfort and heaviness, like an elephant is sitting on the chest, sometimes radiating to the arm, neck or back, and associated with sweating, nausea and breathlessness. This is a medical emergency and needs immediate treatment to restore the blood supply to the heart and minimise damage to the heart muscle; during a heart attack, the heart muscle that received its blood supply from the affected artery will die, healing with time to leave a scar. The larger the scar, the greater the effect on the remaining healthy heart muscle, and the less effectively the heart will work in the future.