The commonest symptoms of a heart attack are unusual discomfort or unpleasant sensation in or around the chest. The true pain may not occur.

1. The feeling of discomfort or pan may be in the middle of the chest or on the left side of the chest. The discomfort may or may not spread to one or more of certain selected regions, such as the left arm, wrist or hand, the neck of the lower jaw, the middle of the back or the shoulders.
   
   
   
2. At times the discomfort may start off in one of these regions and then inversely radiate towards the middle of the chest or the left side of the chest.
   
   
   
3. Rarely the discomfort or pain may be situated only on the right side of the chest and may travel along towards the right arm. Do not ascribe any of the above symptoms to "gas trouble" or "muscle-catch."

Quite often, the subject does not experience any pain. Instead he feels an unpleasant sensation which he cannot describe precisely, such as heaviness, a burning sensation, tightness or the so-called " ghabrahat" in the region of the chest or the arms so outlined in two diagrams. The significance of such " unpleasant " symptoms is the same as that of "pain." The doctor must be informed early even with these symptoms as well.

The symptoms of a major heart attack may come initially with "warning signals" which last for a very short while. Their duration may be only for five to ten or fifteen minutes. They are often brought about by exertion such as walking or climbing, or they may occur after a meal or may even be precipitated by emotional excitement. When the full-blown major attack comes, the pain, discomfort or "ghabrahat" lasts for a longer period of time and may be associated with sweating, vomiting, giddiness or breathlessness.

If from the above symptoms you feel the warning of an impending attack, do not panic but do the following :

1. Take rest - do not exert
   
2. Chew 1 aspirin tablet
   
3. Suck 1/’2 to 1 tablet of nitroglycerine or sorbitrate in the mouth.
   
4. Swallow a tablet of any tranquillizer such as diazepam
   
5. Contact your family doctor or the nearest casualty medical officer in a neighbouring hospital for early diagnosis and adequate treatment of your problem. Heart attacks and their complications can be minimized if the symptoms of a developing attack are treated early within first four hours from the onset of major symptoms.

A note of caution against unnecessary alarm and nervousness :

A number of other disorders may result in symptoms which are similar to those mentioned above . Your duty is not to miss or misinterpret them. With your proper history, the doctor, with his experience, would be able to differentiate the true symptoms from the false ones which might rise owing to disorders of any other organs such as the stomach, esophagus, colon, muscle, spine, nerves, gall bladder, etc. The analysis of pain, especially its location,duration, radiation and character is often a better pointer to a correct diagnosis than even an electrocardiogram which may remain normal in the initial stage. Trust the judgment of the doctor more than that of an electrocardiogram.

For a correct diagnosis by doctor, the patients history in his own words, is most important. A bad witness can spoil the patient’s case, hence, it is advised that he should narrate the symptoms to the doctor exactly as asked. He should not hide anything, nor exaggerate facts nor give his own diagnosis. A normal electrocardiogram is not always a very reliable opinion.

A heart pain or discomfort which is caused by a damaged but viable heart muscle is termed as " angina." When a portion of the heart wall is significantly damaged and is non-viable it is called " acute myocardial infarction" or "coronary thrombosis". The basic disease process in all of the above situations is one of arterial obstruction to the flow of blood. The difference lies in its mechanism, acuteness and the degree of obstruction.

There are two distinct types of angina.

1. "Unstable angina" is acute and its mechanism is through acute crack or a fissure in some intimal atheromatous plaque. The mechanism is similar to acute myocardial infarction but the obstruction is only partial from platelet mischief known as a "white clot" or a platelet clot in unstable angina. In acute myocardial infarction, there is a total blockage with "red clot" or a thrombin clot.
   
   
   
2. The second type of angina is known as "chronic stable angina" without any cracked plaque. It is from gradually increasing cholesterol deposits which progress to create further block in the passage of coronary artery.

Strictly speaking, the term " heart attack" should be used only when a diagnosis of "acute coronary thrombosis" ( myocardial infarction) is made. It is very difficult to further subclassify a particular attack into a so-called minor heart attack or a major heart attack. All heart attacks ( acute myocardial infarction )are unpredictable, particularly in the first week and much more so in the first few hours. If at all possible, they may be subclassified as "uncomplicated " and "complicated. "

The common complications which can occur are :

1. Electrical - such as disturbance of the heart rate or rhythm: and
   
2. Mechanical - the strength of the pumping action of the heart becomes weak, and this can lead to congestive cardiac failure or shock.

Within a few hours to a week of the attack, there is a possibility that an uncomplicated heart attack may abruptly become a complicated one. This may be sudden and may occur in a matter of a few minutes. Hence, the importance of early observation and treatment by modern means, including the use of mobile ambulance coronary care and intensive coronary care unit. It is therefore advisable to treat all heart attacks in the initial period of one week under close observation and vigilance without attempting to sub-classify them into complicated and uncomplicated heart attacks. The conversion time of an uncomplicated attack into a complicated one may be just a few minutes, a situation which nobody, including a doctor can predict.

How To Diagnose Angia (Ischemia)

In stable angina, the symptoms such as the site of pain ( or uncomfortable sensation ), its severity, radiation and character remain the same as in unstable angina or a thrombosis ( infarction ) attack. The main difference lies in its time duration and presence of constitutional symptoms. The angina pain is of a short duration, usually for a few minutes to less than half an hour. The angina pain often comes on during periods when the heart’s work or activity is increased such as physical exertion, after meals or during mental or emotional excitement. There are a few "atypical angina" cases, however, which come on without any triggering mechanism and even can wake up the patient in the middle of his sleep. The electrocardiogram after an angina attack may show only minor changes. It may even remain normal.

Broadly speaking, anginal pains are classified into two general categories :

1. Stable angina - no need for bed rest and
   
2. Unstable angina - need for bed rest

(a) Stable Angina
It is recurrent, chronic and comes on with the usual precipitating factor of exertion, food and emotion. Such recurrent anginal pains can go on for a number of years. As long as they remain stable, the patient does not need bed rest. In a large majority of cases, the disease remains under control with a regulated life style and a strict regimen of drugs. There are a few patients in whom the anginal pain becomes intractable and uncontrollable in spite of medical treatment. It is this group which is likely to be benefited most by modern invasive methods such as stent balloons, or "by-pass."

(b) Unstable Angina
It must be treated cautiously and with best rest. Such episode can as well be a pre-infarction angina. It is called unstable in the following clinical circumstances :

1. Angina for the first time, namely recent angina in its first two weeks, can take an unpredictable course
   
2. A sudden increase in the frequency and duration of chronic stable angina.
   
3. Where a patient experiences a sudden change in the site of the pain or discomfort

Such cases are called " unstable " because their immediate future is unpredictable. The mechanism of a crack in the plaque and formation of incomplete platelet clot has already been mentioned. The crack sealed with platelet plug can ( 1) heal by itself completely (2) progress towards a complete blockage by further addition of a red thrombin clot leading to acute and serious infarction. (3) temporarily heal but may further relapse in a big way in 30% of patients within six months to one year.

Unstable angina can take either of the following courses :

1. It can, in about 30 per cent of patients, deteriorate and suddenly worsen to complicate in to acute myocardial infarction or even sudden death. This phase of unstable angina is also termed as acute pre-infarction syndrome.
   
2. It improves by various protective mechanisms by the activities from platelets, endothelial cells etc. In future, the acute coronary syndrome may or may not recur for a varying period of time. IN 30% of patients it recurs at times in a big way within six months to 1 year.
   
3. The electrocardiogram in unstable angina may show non-q wave or subendocardial infarct. At times, it may remain normal. The study of cardiac injury enzymes would ordinarily remain normal.

How To Diagnose Infarction

The pain or unpleasant sensations are the same as in angina. The difference mainly is in the time frame. The discomfort, however, lasts for a longer time, from half an hour to a few hours. It is likely to be associated with other symptoms such as vomiting, breathlessness, profuse sweating, a fainting spell or change in blood pressure, pulse rate etc.

The electrocardiogram in acute infarction would be most reliable. This is the main aid and it reflects the specific changes in a very short time. Those gross changes of infarction may appear in the electrocardiogram in the first hour in the majority of cases. In some case it may take as much as 24 hours or even more.

Further help in the diagnosis of infarction can be obtained by certain blood enzyme tests in the pathological laboratory. The common blood enzyme tests employed are for serum C.P.K. - MB, S.G.O.T., L.D.H., The C.P.K. and C.P.K. -MB starts rising soon, but returns to normal within 36 hours. The L.D.H. starts rising later after 48 hours and can remain elevated for about two weeks. The S.G.O.T.starts rising after 12 hours, reaches its peak in 36 hours and may return to normal level within 72 hours of infarction. Blood tests for the above enzymes help only in the diagnosis. They do not help in assessing the recovery or progress of a patient. These enzymes including C.P.K. - MB are not specific for the heart. They can also be raised in other acute diseases such as those of the liver, kidney, skeletal muscles, etc. The C.P.K. - MB (myocardial band ) is relatively specific for acute infarction. The reliability is around 95% . In other 5% of patients it can rise from other disorders including unusual physical strain or use of sedative drugs.

Recently, another myocardial protein fraction known as Trophonin - T has become more reliable blood test for the earliest diagnosis of acute infarction.