Question

In all the leads of ECG, all following are positive waves except –

• A. R
• B. Q
• C. T
• D. P

Answer 1

The correct option is B Q

ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle. Each peak in the ECG is identified with a letter from P to T that corresponds to a specific electrical activity of the heart.
The QRS complex represents the depolarization of the ventricles, which initiates the ventricular contraction. The contraction starts shortly after Q and marks the beginning of the systole.


First negative deflection is shown by Q wave followed by positive deflection R wave and again S wave turns negative.

So, the correct answer is- option b.