LESSON 5 – The Golden Rule of ECG Interpretation

Now that we have reviewed the basic normal values, we can move on to the study of abnormalities. We will begin with the most important rule, the failure to follow which inevitably leads to errors and difficulties in ECG interpretation.

“Always follow a clear, structured plan and never deviate from it.”

Even if an obvious abnormality immediately catches your eye—or, conversely, when you look at an ECG and it seems completely confusing—still follow the plan. This approach will help you avoid missing important findings and will allow you to work through even the most complex ECG tracing step by step.

Approximate Plan for ECG Interpretation

• Assess the technical quality of the ECG recording.
• Evaluate the rhythm.
• Determine the heart rate.
• Assess cardiac conduction.
• Evaluate for ischemic changes.
• Assess for the presence or absence of atrial and ventricular myocardial hypertrophy.
• Determine the cardiac axis.
• Evaluate the QT interval.
• Look for other specific features.
• Formulate the final interpretation.

So, following this plan, we will move on to the next section, where real ECG tracings will finally appear. If you remain attentive and persistent, I promise that soon all these seemingly “frightening squiggles” will turn into clear and confident clinical interpretations.