An electrocardiogram, commonly known as an ECG or EKG, is a widely used diagnostic test. It quickly and painlessly assesses the heart’s electrical activity, providing valuable insights into its rate, rhythm, and signs of damage or underlying conditions.
Same Thing, Different Name
The terms ECG and EKG refer to the same medical test, an electrocardiogram. The difference stems from linguistic origins: “ECG” is English, while “EKG” is German (“Elektrokardiogramm”).
The use of “EKG” became prevalent in some regions, particularly in North America, to avoid confusion with the electroencephalogram (EEG), which measures brain activity and sounds similar to ECG. Early German-speaking pioneers, such as Willem Einthoven, also contributed to the adoption of the “K” spelling in the medical lexicon.
Understanding What an ECG/EKG Measures
An ECG or EKG records the electrical signals produced by the heart as it beats. The heart generates impulses that coordinate the contractions of its four chambers, ensuring efficient blood pumping. Electrodes, small sticky patches, are placed on the skin of the chest, arms, and legs to detect these minute electrical changes. These electrodes transmit the signals to the ECG machine, which then translates them into a graphical representation of voltage over time.
The resulting tracing displays characteristic waves corresponding to different phases of the heart’s electrical cycle. The P wave represents the electrical activation (depolarization) of the atria, the heart’s upper chambers. The QRS complex signifies the depolarization of the ventricles, the heart’s lower pumping chambers. The T wave indicates the electrical recovery (repolarization) of the ventricles. Analyzing the patterns, timing, and amplitude of these waves provides healthcare professionals with information about heart function.
Common Clinical Applications
An ECG/EKG is an important tool for diagnosing and monitoring various heart conditions. It is frequently used to detect heart rhythm abnormalities, known as arrhythmias, which include heartbeats that are too fast (tachycardia), too slow (bradycardia), or irregular. The test can also reveal signs of inadequate blood flow to the heart muscle, such as myocardial ischemia, or evidence of a past or current heart attack (myocardial infarction).
An ECG can provide insights into structural changes of the heart, such as an enlarged heart, or detect issues with heart valves. It is also used to monitor the effectiveness of cardiac medications and to check the function of implanted devices like pacemakers. Healthcare providers may recommend an ECG if a person experiences symptoms like chest pain, shortness of breath, dizziness, or palpitations, helping to identify the underlying cause of these issues.