The right answer is by determining changes in the heartbeat
Three questions are unavoidable when interpreting an ECG:
• What is the heart rate?
A normal frequency is between 50 to 100 / minute. Below 50 / min, we are talking about bradycardia, above 100 / min, we are talking about tachycardia.
• Is the heart rhythm regular or irregular (arrhythmia)?
On a normal ECG, the space between 2 Q-R-S is always the same regardless of the time of recording (in green in the following diagram). This question is fundamental to detect arrhythmias.
• Is the rhythm sinus (or normal)?
Each P-wave must be followed by a Q-R-S segment. This question will help identify conduction disorders between the atria and the ventricles.