Whenever the blood supply of the muscular wall of the heart starts suffering, clinical manifestations of CAD – (Coronary Artery Disease) occur. Although there may be a mild blockage in a coronary artery, and thus a depletion in the supply of blood to the walls of the heart, yet this supply may be enough when the patient is at rest. But this supply may not remain adequate when the patient exerts, i.e. when he/she walks, or does some mechanical work. This leads to pain in the chest, and this is called angina pectoris. This pain is temporary, and when the patient stops walking or exerting, the pain diminishes. This pain will also stop when the patient takes some drugs which dilate the coronary arteries, like glyceryl trinitrate, which acts quickly when kept below the tongue or chewed. However, such a pain recurs when the patient resumes walking/ exerting.
Besides exertion, in some other circumstances, the blood supply of the walls to the heart may suffer e.g. when the patient takes heavy meals, which put a stress on the heart or when there is a mental emotional strain caused by anxiety, worry or bad news. An attack of angina may also be precipitated on exposure to cold which may cause pasm/narrowing of coronary arteries.
In anginal pain, the patient feels as if the pain will take the life away. The pain occurs in the centre of the chest, or on its left side. The patient may feel tightness or pressure/ weight-like pain in the chest. The pain hardly lasts for 1-2 minutes, or at the most 10 minutes. As a general principle, pain anywhere in the chest either in front or back of the chest should be considered anginal if it occurs on exertion or during other conditions described, and relieved by rest. Such a patient should be investigated thoroughly. A detailed questioning is required by the physician while taking the history of the case.
The patient often ignores such a pain, or starts doing less exertion so that the pain does not occur again. Hence, awareness/knowledge in this regard is highly needed, so that the patient reports in time and gets himself investigated before it is too late.
The above-said group of cases belongs to stable angina pectoris i.e. in which pain appears on exertion or during other circumstances.
There is another group of anginal cases which is a step ahead of the above group and is called unstable angina pectoris. In this group pain occurs much more frequently with a little exertion. Even a small activity may cause pain in the chest, or at times it may occur even during the period of rest. It is obvious that in these cases the coronary arteries are involved much more than in a case of stable angina pectoris. However, there may not be a complete blockage of the flow of blood in coronary arteries/branches as occurs in cases of a heart attack, in which a very severe pain stays for a long period, and is usually relieved by a pain-killer injection.
The cases of unstable angina should be treated/evaluated on the lines of heart attack. An emergency line of treatment is essentially required in such cases in a well-equipped hospital. If immediate steps are not taken, the patient may suffer from a heart attack, which must be prevented. In some of the cases when drug therapy is not working satisfactorily, even an urgent coronary angiography including angioplasty (ballooning) or surgery may have to be undertaken.
It may be said that a case of unstable angina is like a pendulum of a clock. With timely detection as well as treatment, the pendulum can be made to swing towards stable angina or complete relief, and if proper action is delayed, the pendulum may move to the worst side i.e. the patient may get a heart attack. Hence unstable angina is a danger signal of a heart attack, and it must alert the patient or his attendant to take immediate action, preferably in a hospital.