How to Read and Diagnose an ECG

1. How to read an electrocardiogram

1.1 Read the ECG thoroughly, and pay attention to whether the recorded ECG is a 12-lead ECG. If the recorded leads are incomplete, the final diagnosis of the ECG may be affected.

1.2 Judging whether the connection of each lead is correct, the most common mistake is to reverse the connection of the leads of the two upper limbs, so that the ECG pattern of the 6 limb leads resembles dextrocardia changes. ) was inverted, but there was no characteristic dextrocardia change in the anterior chest leads.

1.3 Observe whether the P wave shape, polarity, duration and frequency of each lead are normal, focusing on leads II, II, avR, avF, and V1. When it is normal, it is sinus rhythm, otherwise it is ectopic rhythm.

1.4 Measure the QRS wave duration, polar direction and amplitude height, these measured values are all in the normal range (0.06~0.10s), that is, the ECG is normal, otherwise it is abnormal. Note that the measurement of QRS timing should select the widest QRS complex in the 12 leads.

1.5 Measure the length of PR interval, which is abnormal if it is shorter than 0.12s or longer than 0.20s.

1.6 Observe and measure the ST segment T wave, ST segment depression and elevation exceeding the normal value are abnormal. Flat, inverted T waves are also considered abnormal.

2. ECG diagnosis steps and report content At present, the basic content of ECG diagnosis and report is carried out in a certain order. When reading and interpreting ECG, all manifestations that can be seen in ECG should be analyzed and described, mainly including:

2.1 Basic heart rhythm: determine whether the basic heart rhythm of the ECG is sinus rhythm or ectopic rhythm, and determine the heart rate.

2.2 Conduction interval: measure PR interval, ST segment, QT interval, and mark specific values.

2.3 Cardiac axis: Measure the QRS wave axis.

2.4 Describe the duration and shape of the QRS wave.

2.5 Describe the ST segment and T wave.

In short, when reading and analyzing the ECG, the time limit of each wave and each interval should be carefully measured, and the reasons for the change of rhythm and waveform should be carefully analyzed, in order to make the final correct diagnosis.