What does a grid on an electrocardiogram represent

Time : 2022-08-11

There are many cells on the ECG chart, and each of these cells has a thin vertical line and a thin horizontal line 1 mm apart. The thick line is one for every five small grids, and the interval between each thick line is 5 mm, and the thick lines form a large grid. The ECG chart moves at a standard speed of 25mm/s, the distance between each two thick lines represents 0.2s, and each small horizontal unit represents 0.04s. Internationally, there are regulations on the voltage applied when recording electrocardiograms. Each small division represents 0.1 mV, each large division represents 0.5 mV, and every two large divisions represents 1 mV. That is, when a voltage of 1 mV is applied, the baseline should rise by exactly 10 small divisions.

Each small grid on the ECG chart has different meanings, some represent time, and different times may represent different heart diseases. The specific heart rate can also be determined by the time of the small grid. The ECG chart must be analyzed in detail by a professional doctor to clarify which aspect of the heart abnormality is. At the same time, it can also be combined with echocardiography, and the results are clear.

Special ECG charts have horizontal and vertical interwoven lines that form a number of very standard grids between them. The two vertical lines of each small grid are 1 mm apart, which represents 0.04 seconds; the two horizontal lines of each small grid are also 1 mm apart, which represents 0.1 millivolts of voltage.. The paper speed of the ECG drawing must be 25mm per second, The calibration of the voltage must be 10 small divisions. If the feed speed is 50 mm per second, each cell represents 0.02 seconds; if the voltage calibration is halved to 5 cells, then each cell represents 0.2 millivolts at this point, but this is used in special cases .

The speed of a conventional ECG chart is 25 mm per second, a small grid is 1 mm, that is, a small grid is 0.04 seconds; a large grid is five small grids, which is 0.2 seconds. To calculate heart rate quickly and easily, there is a simple method. If the PP interval or the RR interval is three large divisions, it is 0.6 seconds. That is, a jump every 0.6 seconds, 60 seconds per minute, the heart rate equals 60 ÷ 0.6 = 100 beats per minute. If it is 4 large divisions, it is 0.8 seconds and the heart rate is 75 beats/min. If it is 5 large divisions, it is 1 second and the heart rate is 60 beats/min.

There are many types of electrocardiographs:

① There are tubes, transistors, small-scale integrated circuits, large-scale integrated circuits, etc. According to original equipment.

②According to the current classification, there are AC, DC, AC, DC, etc.

③ According to the recording method, there are hot pen type, thermal vibration type, computer stylus printing, inkjet printing, laser printing and so on.

④ According to the type, it is divided into portable type, desktop type and mobile type.

⑤ According to the function classification, there are single function and multi-function.

⑥ The electrocardiographs recorded at the same time with single lead, 3 leads, 4 leads, 6 leads and 12 leads are usually classified into different categories.

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