Angina's pain level is a poor guide to how endangered the heart is
The name means a strangling feeling in the chest, and it usually signals that heart muscle is short of blood. Yet how much it hurts can mislead: some people have fierce pain with little heart-attack risk, while others suffer a heart attack and feel almost nothing.
Angina pectoris comes from the Latin angere, to strangle, and pectus, chest. The discomfort or pressure arises when blood flow to the heart muscle falls short, most often because the coronary arteries are partly blocked or go into spasm. The chief culprit is atherosclerosis, the fatty narrowing at the heart of coronary artery disease. Irregular heart rhythms, heart failure and, less often, anaemia can also cause it. Because it can signal something serious, prompt medical assessment is advised.
The classic form, stable or effort angina, appears with exertion such as walking or running, fades within minutes of rest or a dose of nitroglycerin under the tongue, and returns when activity resumes. Cold weather, big meals and emotional stress can trigger it too. In this pattern the fatty plaque inside the artery is still covered by a fibrous cap.
Unstable angina is a different beast and counts as a medical emergency. It is new and severe, strikes at rest, or grows noticeably worse, longer or more frequent. Here the cap over the plaque can tear, letting clots form and narrow the vessel further, which explains why attacks need not follow effort. Platelet clumping and arterial spasm can also cut flow. One finding is striking: 64 percent of unstable episodes occur between 22:00 and 08:00, while people are resting. Because it can herald a heart attack, doctors generally handle it much as they would one.
A third type, microvascular angina or cardiac syndrome X, produces the same chest pain even though the large surface arteries look normal on imaging. Its cause is not established, but faulty vessel linings and reduced flow in the heart's tiniest vessels seem involved, which makes it hard to diagnose. Once thought fairly harmless, it is now seen, partly through the WISE study, as a genuine form of ischaemic heart disease that may help explain why women report angina more often. Outlook has changed too: severe angina once meant approaching death, but middle-aged patients with moderate to severe symptoms now have roughly 92 percent five-year survival.
Source: Angina
