Cardiac Enzymes

Enzymes are found throughout the body and are released to enable chemical reactions and responses to take place.Cardiac enzymes are chemical substances made up of proteins that are essential to enable function of the heart muscle.

These enzymes are always present in the blood, even in those with good health, but they are released to higher concentrations when the heart tissues become damaged or have to work harder.

What Are The Main Cardiac Enzymes In The Body?

The main cardiac enzymes found in the heart tissues are troponin T, troponin I, creatine kinase (CK), aspartate aminotranferase (AST) and lactate dehydrogenase (LDH).These enzymes all rise and peak at differing times after heart muscle injury and the elevations can remain peaked for several days, though these times are also variable with the different enzymes.

Are Cardiac Enzymes Important?

These enzymes are extremely important and testing for them can tell doctors whether or not the cardiac muscle has been damaged in some way, for example when a heart attack has taken place.

When the cells of the heart become damaged, the membranes within the cell become weakened causing the enzymes contained in the cell to seep out into the blood stream.The more damaged sustained by the heart, the greater the concentrations of the enzymes in most cases.

Cardiac Enzyme Tests.

Testing for cardiac enzymes is a routine part of diagnosing damage to the heart, particularly when a heart attack is suspected. The test is not carried out alone and a full examination of the patient will be needed along with other tests such as an electrocardiogram (ECG). This is because raised levels of cardiac enzymes does not automatically mean that a person had suffered a heart attack as raised levels are also present in many other conditions of the heart also.

The testing is performed by obtaining a blood sample and finding out if there are high concentration levels of the enzymes in the blood. As these concentration levels can rise slowly as more leak into the blood stream. It is often common practice to repeat the test after some time has lapsed and levels reassessed.

The results from the tests are usually available quite quickly (often within an hour or two) due to their use in emergency patients and the need for physicians to make a fast and accurate diagnosis.

Separate tests are usually carried out also to test for levels of the different types of cardiac enzymes and some are more reliable than others.Testing for troponin T and I are becoming the most popular testing techniques as the results are more accurate and specific to heart injury and the levels remain raised for longer periods of time, though most doctors will also routinely test for the other enzymes as well.

Cardiac enzymes are chemicals that are found naturally in the blood. Their levels become raised as a result of injury to the heart muscle and a simple blood test can be performed to help make a diagnosis. The test is commonly performed if a heart attack is suspected and has become a routine part of making such a diagnosis.

Unfortunately some heart attacks can be immediately fatal, and those that aren't need immediate medical attention, but the chances of survival of these people can be greatly increased by ensuring that some basic life support techniques are carried out whilst waiting for medical assistance.Every second is vital in ensuring good recovery rates with a lower chance of long term problems.Heart attacks do not have to be sudden and intense, they can in fact develop slowly, worsening gradually.

Is it a Heart Attack?

The most obvious signs that someone is having an intense sudden heart attack include:

• Clutching of the chest; this pain can be centralised in the chest cavity or radiate to the left shoulder and down the left arm.
• Painful expressions; many people will show an immediate sign of intense pain and facial expressions will easily convey this.
• Shortness of breath; this can include gasping or short sharp intake of breath.Collapse; the person falls to the ground.

Signs of a heart attack that worsens over time include:

• Complaining of persistent heart burn or indigestion.
• Sweating but shivering at the same time.
• Looking pale.
• Feeling nauseous.
• Chest pain develops slowly.

Immediate First Aid

These guidelines are in no way to act as an alternative to professional medical help and should be used whilst waiting for help to arrive. They apply to adult life support only as paediatric guidelines vary.

First of all, it is essential to determine whether the area around the person is safe for you to enter. Electric shocks can cause a cardiac arrest so ensure there are no live electrics around. Make sure there is no broken glass or other obstacles in the way.

Initially, discover if the person is responsive. Gently shake them and ask if they can hear you. Do not do this too violently in case of injury or if the person has fallen hard and fractured their skull. Find out if the person is breathing or not. Watch for signs of the chest cavity rising and falling and feel for exhaled air from the nose or mouth.

Check for a pulse using either the pulse point on the wrist or on the side of the neck. Do this using two fingers placed directly but not too hard onto the area and leave in place for at least 30 seconds. A pulse can be weak, intermittent or very slow in these cases.If a pulse is present try and determine why the person is not breathing. Is their airway obstructed by something? Is there a tightly fitting tie around their neck? Tilting the head back and gently opening the mouth using two fingers observe for anything that may have become lodged in the throat.

If the airway is clear, run and call for help. Assess regularly.

Find out if anyone around is familiar with CPR techniques.Whilst the casualty is laid on their back, tilt the head and chin upwards and slightly back to open the airway.Placing the hands, one on top of the other, to the centre of the chest give 30 compressions to 2 breaths. Try and find someone to help do this as it can be exhausting for one person.

To give a breath, tilt the head back and block the nose by pinching with finger and thumb, give one deep breath into the persons mouth. Whilst doing this look for the chest rising informing you that the air has gone into the lungs.Repeat the pattern of 30 compressions to 2 breaths until help arrives.

The methods given are to be used in an emergency only. Always try and find a medically trained person as this will increase the chances of the person surviving.The methods detailed were as per government guidelines at the time of publication, but are subject to frequent change as research provides more information on which to base the guidelines on.