Systematic ECG interpretation follows a fixed sequence: verify voltage calibration, determine the rhythm (identifying whether P waves consistently precede QRS complexes, indicating normal sinus rhythm), calculate heart rate, measure timing intervals (PR, QRS duration, QT), determine the electrical axis, and evaluate P wave, QRS, ST segment, and T wave morphology, comparing to a prior baseline when available. Each parameter has defined normal ranges and characteristic deviations that map to specific pathophysiology—such as atrial enlargement, conduction abnormalities, ischemia, electrolyte disturance, or drug effect—making the ECG a standardized tool for inferring cardiac electrical and structural status. This is a topic in cardiology concerned with the formal method of electrocardiographic diagnosis.
Systematic ECG interpretation follows a fixed sequence: verify voltage calibration, determine the rhythm (identifying whether P waves consistently precede QRS complexes, indicating normal sinus rhyth…