APPROACH TO READING THE ECG
ECG or EKG (the electrocardiogram) has retained its role as the first and foremost investigations for many cardiovascular diseases. ECG is absolutely mandatory for diagnosis of heart rhythm and for myocardial ischemia. It has a prominent role in the diagnosis and management planning of a variety of cardiac diseases starting from heart failure and cardiomyopathy to valvular diseases and pericardial diseases.
Health care professionals are expected to be familiar with ECG. But to make sense of the variously shaped lines we need a few basic steps. Is article is part of a series of articles on ECG.
There is a systematic approach to reading the ECG. Medical students should always try to make a written report of the ECG according to the heading as listed below. Try to report as many ECGs as you get, and try to remember the systematic approach to ECG reading.
Now lets start with our ECG reading.
1. Speed – Paper speed is conventionally 25 mm/sec. It is normally written at the bottom of the Ecg.
2. Calibration – Vertically, the ECG graph measures the height (amplitude) of a given wave or deflection, as 10 mm (10 small boxes) equals 1 mV with standard calibration. Always check the calibration otherwise a false diagnosis of chamber enlargement or hypertrophy will be made or missed.
6. Loop (mainly in congenital heart disease)
8. PR- interval
9. QRS complex
10. ST- segment
12. QT- interval
13. U- Wave
14. Any other abnormal waves (like:- osborn wave, epsilon wave etc)
These 14 points when remembered and applied in the analysis of ECG will give the diagnosis in almost all cases.
We will further delineate each point in simple and clear terms in the subsequent posts.