EKG
What is an EKG?
EKG stands for electrocardiogram. The abbreviation comes from the German elektrokardiogramm. An EKG is used to measure the activity of the heart and check for any abnormalities. Each of your heartbeats is caused by an electrical impulse usually generated in the upper right chamber of the heart. Measuring these electrical impulses, the EKG looks for patterns amongst the rhythms that may sometimes denote particular heart conditions.
It is a painless and non-invasive procedure. Leads are attached to the skin at various parts of the body and readings are correlated. Health professionals can usually read and report back on your EKG the same day, often within the same appointment. This means that follow-up appointments can be arranged efficiently if the results of the EKG suggest them to be necessary.
When is an EKG used?
An EKG may be used in a variety of situations. Your doctor may decide to perform an electrocardiogram as part of an ordinary medical check-up or also in response to the following symptoms:
- Chest pain
- Shortness of breath
- Fainting/dizziness
- Palpitations
- Heart attack or as a regular check-up after a previous heart attack
An EKG can also form part of a cardiac stress test or as part of a series of pre-operative tests for anyone who may be at risk of heart disease.
What conditions can an EKG detect?
An EKG may provide evidence and give further details of several conditions:
- Cardiac dysrhythmia – irregular heartbeat. If the heart appears to be beating too fast, too slow or irregularly, then a EKG can give more information.
- Pulmonary embolism – blockage of the artery of the lung. This can happen if a substance travels from one part of the body to the heart artery through the bloodstream. It can happen with deep vein thrombosis, where a part of the clot breaks off and travels to the lung.
- Heart attack – if one of the coronary arteries is blocked in any way (by white blood cells, cholestoral or fat) it can stop enough oxygen reaching the heart. An EKG will measure the heart's activity.
- Hypercalcaemia/hypocalcaemia – too much or too little calcium in the blood.
- Hyperkalemia/hypokalemia – too much or too little potassium in the blood.
- Coronary ischemia – too little blood in the coronary arteries.
Of course, an EKG may also show no problems at all with the heart and the decision to conduct an EKG should not be taken as indicative of any major problem.
When Would I Need an EKG?
Concerned patients can choose to have an EKG conducted privately as part of a heart health check-up but normally a doctor or health professional will know when to recommend an EKG. The procedure is simple and costs very little. An EKG is usually conducted as part of a series of procedures but may also be performed in the emergency situation of a heart attack.
How Do I Prepare for the Procedure?
No preparations are necessary for an EKG. It is sensible to avoid exercise, such as climbing the stairs or running to an appointment prior to the test as this could increase your heart rate, giving misleading results but there is nothing particular patients need to do to prepare for the test.
How is the EKG conducted?
An EKG is a simple procedure. It is non-invasive and perfectly safe. When the patient is in a lying position, electrodes are attached to the skin in several places – usually the arms, legs and chest. Normally between twelve to fifteen electrodes are used. First, the skin is cleaned and shaved then the electrodes are applied. They are simply sticky patches and should cause no discomfort. Patients lie still and breathe normally and the test lasts only a few minutes. Older machines might require patches to be moved around the body to give a complete reading.
How does it work?
The EKG machine detects and amplifies the tiny electrical changes on the skin, which are caused when the heart muscle depolarises with each heartbeat. At rest each heart muscle cell has a negative charge and with each heartbeat, the negative charge moves towards zero in a process called depolarization. A healthy heart will have a predictable regular wave of depolarization. This can be detected as rises and falls in the voltage between two of the electrodes placed on either side of the heart. This is then represented by a wavy line that can show the overall rhythm of the heart as well as indicate weaknesses in particular parts of the muscle.
What do all the different electrodes do?
The reason for the high number of electrodes is to be able to build up a big picture of how the heart is behaving. Electrode pairs placed at opposite parts of the body can show how particular areas of the heart may be weakened. Since the electrodes are detecting changes in the electrical impulses of the skin, not directly monitoring the heart, a larger number allows for more accuracy in the results.
What happens after the test?
AAn EKG monitors activity and produces instantaneously the waveforms, which are then interpreted by the clinician. Since the test results are in this way immediate, patients can hear feedback almost straight away. Interpreting the results may take some time but clinicians normally give results the same day. If the results show everything is normal, no further tests may be necessary but if issues come to light, a repeat EKG may be administered or further tests like an echocardiogram.
What are the limitations of an EKG?
An EKG gives a static image of these electrical impulses (and thus your heart's behaviour) so it is most useful when symptoms are actually presenting. If symptoms are intermittent, then an EKG may not detect problems. This means that quite severe underlying heart conditions may go undetected by the EKG if the patient is not presenting suffering symptoms. For example, a patient experiencing intermittent chest pain caused by coronary artery disease may have an entirely normal EKG reading if their symptoms are not presently current. Sometimes anEKG is conducted both at exercise and at rest to increase the chances of abnormalities being detected.
Furthermore, EKG results are often non-specific, meaning that an EKG alone is not enough to diagnose an underlying condition. The same patterns and waveforms appear in a variety of different conditions. Usually, a variant waveform is in fact not indicative of any abnormality at all. For this reason, it is important that any indications of the EKG are analysed by an expert. A physician will be able to consider the test results in light if the symptoms described by the patient, the patient's medical history, a thorough examination and potentially other tests.
It is also possible that a patient may have a normal EKG result in spite of an underlying condition. A normal EKG result should no more be taken a sign of definitive illness than it is of definitive health, for there are always exceptions, requiring the doctor's analysis.
How Can These Limitations Be Worked Around?
Oftentimes, an EKG is used in conjunction with other tests so some of these limitations pose little real problem.
If it is the case that symptoms are irregular, then there are several options available:
- Holter monitoring – a device that monitors the electrical impulses for a 24- hour period. Patients are asked to keep a concise diary of their activities which can be cross-referenced with the readings.
- Event monitoring – monitoring the heart only when symptoms are occurring. The results can be sent to the doctor via the telephone.
- Stress test – if the other types of testing do not uncover anything, conducting an EKG while the patient is exercising (the heart is stressed) can provide alternative analysis.
Are there any other risks?
The procedure is very safe. Patients may experience very slight discomfort when the electrodes are removed from the chest but this will not be any greater than the feeling of removing a bandage. Skin reactions to the electrodes occur only very rarely and tend to be only slight redness or swelling.
If the EKG is carried out as part of a stress test, that is, during exercise, then the exercise itself may lead to irregular heartbeats, but this is unrelated to the EKG itself.
There is no electrocution risk. The electrodes placed on the body only record electrical impulses, they do not carry electricity themselves.
What treatment will be offered?
An EKG alone is not usually used to diagnose a condition. Rather it is one tool at the disposal of a clinician assessing heart health. As a result, there are no treatments associated with the test. If the test indicates heart problems, then the treatment offered will depend on the condition detected, the patient's lifestyle and many other factors.
Your doctor or health professional can advise you as to what is most healthy for your heart and your condition. If one is detected, and in these instances, patients should refrain from self-diagnosis and always seek medical advice when concerned.
The Art of Healing
Dr. Roya Golshani, a board certified primary care physician, has been practicing general internal medicine since 2002. She is a passionate internist who not only practices internal medicine, but specializes in Women’s Health as well. With her additional training in medical, developmental, and psychological issues, she is fully capable of working with you to solve your problems. Talk with her today to
learn more about the EKG and how you can benefit from it.
• To listen to you with care and compassion
• To help you make the right choices for your health
• To respect your individuality and your goals
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