Electrocardiogram (ECG or EKG for short) is a common medical test that records the electrical activity of the heart to evaluate heart function. It captures the electrical signals generated when the heart beats through electrodes attached to the skin and converts them into waveforms to help doctors diagnose heart diseases such as arrhythmia, myocardial ischemia, and myocardial infarction. Electrocardiogram is non-invasive, rapid and an important tool for cardiovascular disease screening and monitoring.

The working principle of the electrocardiogram is based on the electrophysiological activity of the heart. Before each heartbeat, the heart generates a weak electrical signal to prompt the heart muscle to contract. These electrical signals are conducted to the body surface through human tissue, captured by electrodes, amplified and recorded. Typical ECG waveforms include P wave (atrial depolarization), QRS complex (ventricular depolarization), and T wave (ventricular repolarization). By analyzing the shape, intervals, and rhythm of the waveform, doctors can determine whether there are abnormalities in the heart.

The clinical application of electrocardiogram is very wide. It is not only used to quickly identify myocardial infarction in emergency rooms, but also to screen for hidden heart disease during physical examinations. Dynamic electrocardiogram (Holter monitoring) can continuously record 24-hour cardiac electrical activity and is suitable for the diagnosis of paroxysmal arrhythmia. In addition, exercise stress electrocardiography can assist in the diagnosis of coronary heart disease by observing electrical changes during exercise. The types and functions of electrocardiogram equipment also vary in different scenarios.

Currently, electrocardiogram equipment on the market is mainly divided into three categories:static electrocardiograph(such as Nippon Optoelectronics ECG-1350),Portable Holter ECG Recorder(such as the American BIOTRONIK ARTEMA series) andWearable ECG monitoring device(Such as the electrocardiogram function of Apple Watch). The following is a comparison of some manufacturers and products:

Nobel Prize winner in Physiology Wilhelm Einthoven invented the first practical electrocardiograph in 1903, laying the foundation for modern electrocardiographic diagnosis. Today, as technology advances, artificial intelligence-assisted analysis (such as AliveCor’s KardiaMobile) has further improved the convenience and accuracy of ECGs. However, it should be noted that ECG results need to be interpreted by professional doctors, and home equipment is for reference only.

Quote source:
1. American Heart Association (AHA) "Clinical Guidelines for Electrocardiography"
2. Wilhelm Einthofen, "Studies on the Electrical Activity of the Heart" (1924)
3. National Medical Products Administration Medical Device List