You might not realise it, but your heart runs on electricity. Specialised cells spread all over your heart fire electrical signals to coordinate your heart’s pumping action.
An electrocardiogram (EKG or EKG) is an incredibly valuable, non-invasive tests that records your heart’s electrical signals. This can help your healthcare team identify if anything is wrong, such as an irregular heart rhythm or narrowed arteries.
Your doctor might conduct an EKG for a few reasons:
- As part of a routine checkup to assess your overall health
- As part of a pre-operative assessment
- If you are experiencing chest pain
- If your pulse is rapid
- If you are short of breath
- If you’ve been feeling dizzy or lightheaded
- If you’ve been feeling fatigued
What Happens During An EKG?
Your doctor or nurse will place small adhesive electrodes on specific areas of your skin, on your chest, arms, and legs. These electrodes detect the electrical signals generated by the heart.
The electrodes are connected to an EKG machine. The machine records the electrical activity of your heart, measuring the voltage changes produced by the heart’s electrical impulses as they travel through the heart muscle.
The EKG machine produces a graphical representation of the heart’s electrical activity, as picked up by the electrodes. The representation is displayed as a series of waves and intervals on a paper strip or digital screen. The standard EKG wave is a fairly common medical image – you might have seen it as part of the GlobMed brand!
Interpreting EKG Results
The EKG waves follow a very specific pattern. The waves and intervals correspond to different phases of the cardiac cycle:
- P Wave: The first waveform in the sequence represents the electrical activity associated with atrial depolarization (contraction).
- QRS Complex: The big spike that we all associate with an EKG image. The Q is the dip before the high R spike, followed by the low S dip. The QRS complex represents the electrical activity associated with ventricular depolarization (contraction).
- T Wave: Is a small bump in the wace, representing the repolarization (resetting) of the ventricles.
- PR Interval: The time from atrial depolarization to the beginning of ventricular depolarization.
- QT Interval: Measures the time from ventricular depolarization to ventricular repolarization.
Don’t worry if this seems a bit confusing – you won’t be left to interpret your own EKG results. A trained healthcare professional, such as a doctor or cardiologist, will interpret the EKG tracing.
They will analyse the waveforms, intervals, and overall pattern of the electrical activity to assess the heart’s rhythm, identify any abnormalities, and diagnose conditions such as arrhythmias, heart attacks (myocardial infarctions), and other cardiac disorders.
What Happens If My EKG Results Are Abnormal?
If your EKG results come back as abnormal, it suggests that there might be irregularities in the electrical activity of your heart. This doesn’t necessarily indicate a serious issue, but your doctor will likely want to investigate further.
Your doctor will take into consideration your medical history, symptoms, and other risk factors in conjunction with your EKG results. They might recommend additional tests like an echocardiogram, stress test, or Holter monitor to gather more information about your heart’s function.
Your doctor will only make a diagnosis when they have all the information they need. If necessary, they will create a treatment plan tailored to your condition.
Your treatment will depend on the type of diagnosis your doctor gives, but it might involve lifestyle adjustments, medications and regular monitoring or follow-up appointments. Remember, while an abnormal EKG can raise concerns, it’s a starting point for further evaluation and doesn’t always indicate a serious problem.
What Could Possibly Be Wrong?
Abnormal heart rhythms are one of the most common findings in abnormal EKGs. These can include atrial fibrillation, ventricular tachycardia, bradycardia, or other irregular rhythms. An EKG might also detect:
- Conduction Abnormalities: Problems with the heart’s electrical conduction system, such as bundle branch blocks, heart blocks, or Wolff-Parkinson-White syndrome.
- Cardiomyopathies: Conditions that affect the heart muscle’s structure and function can manifest as EKG abnormalities, like dilated cardiomyopathy or hypertrophic cardiomyopathy.
- Hypertrophy: An EKG might show patterns indicating thickening of the heart muscle (ventricular hypertrophy), often due to conditions like hypertension or heart valve disease.
- Ischemia: Reduced blood flow to the heart muscle, known as myocardial ischemia, can lead to changes in the EKG pattern, such as ST-segment depression or T-wave inversion. This could suggest underlying coronary artery disease.
- Indications for a heart attack: Changes in the heart’s electrical pattern that might indicate a heart attack, especially if there are ST-segment elevations or depressions.
- Pericarditis: Inflammation of the pericardium (the sac surrounding the heart) can cause specific EKG changes, such as PR-segment depression and diffuse ST-segment elevation.
- Long QT Syndrome: This is a congenital or acquired condition where the QT interval on the EKG is abnormally prolonged, increasing the risk of dangerous arrhythmias.
- Electrolyte Imbalances: Certain electrolyte abnormalities (such as high or low potassium levels) can lead to EKG changes that indicate heart rhythm disturbances.
- Drug Effects: Some medications and drugs can alter the heart’s electrical activity and show up as EKG abnormalities.
- Injury or Trauma: An EKG might indicate heart damage due to trauma or other causes, such as contusions or electrical injuries.
- Stress: Emotional or physical stress can cause temporary EKG changes that might not necessarily indicate a heart condition.
Frequently Asked Questions
On average an EKG takes about 5 to 15 minutes, depending on how many electrodes are used, how cooperative the patient is and how efficient the healthcare provider.