What does the ECG and EKG record?

Electrocardiogram (ECG) and Electrocardiograph (EKG) are interchangeable terms used to describe the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin's surface. ECG/EKG provides valuable information about the heart's rhythm, rate, and any abnormalities in the electrical conduction system of the heart. Specifically, the ECG/EKG records and displays:

1. Heart Rate and Rhythm: The ECG shows the heart's rate, which is the number of times the heart beats per minute, and its rhythm, which is the regular or irregular pattern of heartbeats. A normal heart rate for adults at rest ranges between 60-100 beats per minute.

2. Electrical Conduction: The ECG captures and records the electrical signals generated by the heart throughout each heartbeat cycle. It allows the evaluation of the electrical conduction pathways within the heart. These signals represent the electrical impulses that spread through the heart muscle, initiating each contraction and causing the heart to beat.

3. Cardiac Intervals and Segments: The ECG helps measure the duration of various electrical events in the cardiac cycle. It identifies different intervals and segments, such as the PR interval, QRS complex, and QT interval, which provide insights into the timing of electrical events within the heart's chambers.

4. Arrhythmias: ECG/EKG is instrumental in detecting and diagnosing arrhythmias, which are abnormal heart rhythms. Arrhythmias can range from harmless and occasional extra beats to more severe and potentially life-threatening disturbances. The ECG can help identify the type of arrhythmia and assess its severity.

5. Myocardial Ischemia and Infarction: The ECG can indicate myocardial ischemia, which occurs when there is reduced or blocked blood flow to the heart muscle due to coronary artery disease. It can also reveal signs of a myocardial infarction (heart attack), such as ST-segment elevation or depression and abnormal Q waves.

6. Cardiac Conduction Defects: ECG/EKG can detect conduction defects within the heart, such as bundle branch blocks, atrioventricular (AV) blocks, or Wolff-Parkinson-White syndrome, which can affect the normal and coordinated electrical conduction within the heart.

By recording the electrical activity of the heart, the ECG/EKG serves as a non-invasive, crucial diagnostic tool for evaluating various heart conditions, guiding treatment decisions, and monitoring the effectiveness of cardiac interventions.