What is the difference between stable and unstable angina?

Hi, I'm Sukhnidhja and I'm an interventional cardiologist working in central London and part of my work involves dealing with people with angina and this is an incredibly common condition. One common question we get asked is what's the difference between stable angina and unstable angina? Well, this is partly a terminology and something that many doctors use sometimes interchangeably but there are fairly strict definitions of when things are stable and when things are unstable. Stable angina is typically a discomfort that comes across the chest that may radiate up into the jaw, the neck or into the arm and it can be either arm. This typically comes when patients are undertaking activity and goes away when patients rest and that would be stable angina. Unstable angina can have a number of different characteristics and this typically can occur when the patient is resting so they may have a sense of chest tightness with the same features moving up into their neck or into their arm but it is occurring when the individual is resting and not when they're exerting themselves. There may well be some characteristic changes on an ECG if taken at the time of symptoms but they should not have an elevation of their blood enzymes. So a blood test that we commonly perform in hospital is something called a cardiac troponin. This is a cardiac enzyme that tells us whether any heart damage has occurred. In unstable angina cardiac enzymes should not be elevated. There are a number of other types of unstable angina and it's worth considering those. For example, angina of new onset that hadn't been occurring before is also referred as unstable angina. An angina that's got progressively worse over a short period of time is also referred to as unstable angina. One can imagine a patient having chest tightness on a Monday, perhaps only when they did significant activity, Tuesday, perhaps when they're doing lighter work, on Wednesday even when they're walking around the home and then by Thursday they may well be having chest tightness just when they're resting and that is unstable angina. In the case of unstable angina it would be worth it getting the patient admitted into hospital and performing some investigations as it is likely that there has been some change in their heart arteries that is unstable and could progress on to forming a heart attack. Stable angina on the other hand tends to be static and stable for quite some time and in general patients with stable angina can be managed quite safely with a combination of medicines, testing and in some cases if the symptoms are still troubling by performing an angiogram and by performing angioplasty. So in this video we've discussed the differences between stable and unstable angina.