Angina is the term used to describe chest pain caused by a decreased blood flow to the heart muscle. The pain can feel very similar to a heart attack - a squeezing, intense pain in the left-hand side of the chest. It can be coupled with nausea and shortness of breath. The pain can radiate to the left arm or the jaw. 

There are two main types of angina - stable and unstable. Easy right?

Angina is classified as stable when the pain only occurs during exertion - high levels of anxiety, exercise, etc. - Basically anything that makes your heart work a bit harder. The increased workload increases the heart's demand for blood supply (the fuel) - and this added demand can't be fulfilled, leading to pain. 

When you have symptoms of stable angina (ie. it goes away when you relax) - you will need to be investigated, usually as an outpatient. Along with an ECG and an echocardiogram, an exercise stress test will be performed. We record a continuous ECG while you do exercise on a treadmill or exercise bike. We do this to recreate the environment in which you experience chest pain - hoping that we can pick up an abnormality on your ECG that isn't there when you are at rest. If we see any abnormalities - you will likely need a coronary angiogram (see cardiac investigations). 

Angina is classified as unstable when it occurs at rest - meaning you're sitting on your couch when the pain starts. Unstable angina is reflective of a more significant issue with blood supply to the heart muscle - as such, it is considered an ACS (Acute Coronary Syndrome).
The other two things considered an ACS is a STEMI (major heart attack) and an NSTEMI (minor heart attack). 

As such, patients experiencing unstable angina will usually have had a heart attack in the past with stents placed in the coronary arteries. If the pain in usually quite rare and happens all of a sudden, the cardiologist will want to repeat a coronary angiogram to ensure the coronary arteries and stents look good. Sometimes however, if you've had a recent angiogram and there isn't much more the doctors can do to improve the arteries - we will treat your pain medically. 

GTN is a spray we advise to use under the tongue to relieve symptoms of angina. GTN stands for Glyceryl Trinitrate, and as a nitrate, it works by dilating the vessels. It relieves the chest pain by widening the coronary arteries and restoring adequate blood flow to the heart muscle. The nitrate medication will also widen other vessels in the body lowering the blood pressure temporarily, which is why you can feel slightly dizzy after using the medication - it may also cause a headache. As such, please use the GTN periodically as the doctor prescribes. 

If you are requiring your GTN very regularly, a longer term nitrate medication can be commenced which will work consistently in the background. This is called ISMN - Isosorbide Mononitrate. It also sounds rather complicated, but all we're doing is widening a narrow pipe!