Question

Given below is the ECG of a normal human. Which one of its components is correctly interpreted below?

• A. Complex QRS - one complete pulse
• B. Peak T - Initiation of total cardiac contraction
• C. Peak P and peak R together - Systolic and diastolic blood pressures
• D. Peak P - initiation of left atrial contraction only

Answer 1

Answer: (A)

Complex QRS - one complete pulse

P wave is the contraction of the atria.
By counting the number of QRS complexes that occur in a given time period, one can determine the heart beat rate of an individual. The QRS complex represents the depolarization of the ventricles, which initiates the ventricular contraction.
T wave represents the repolarization ( relaxation of ventricles ) of the ventricles.