Standard recording speed of an electrocardiographic paper – Cardiology MCQ – Answer

Standard recording speed of an electrocardiographic paper is:

Correct answer: b) 25 mm/s

With standard recording speed, 1 mm on the horizontal axis (X-axis) of the ECG graph will represent 40 ms. Standardization for recording voltage is 10 mm to 1 mV. Hence 1 mm on the vertical axis (Y-axis) of the ECG graph will represent 0.1 mV or 100 micro Volts.

In fast rhythms sometimes we may resort to higher recording speeds like 50 mm/s. It may be noted that intracardiac electrograms during and electrophysiology study (EP study) is much higher at 100 – 200 mm/s. This is essential to recognize subtle differences in the intracardiac activation patterns to decipher the origin and mechanism of heart rhythm disorders.

Back to question