Question

In a standard ECG, one of the following functions of its components is not correctly interpreted.

• A. P is the contraction of only left atria.
• B. QRS complex represents ventricular contraction.
• C. T is the end of systole.
• D. P is the contraction of both atria.

Answer 1

The Correct Option is A

Let's evaluate each statement regarding the components of an ECG:

P is the contraction of only the left atria:

• This statement is incorrect. The P wave represents the depolarization of both atria (left and right). It does not specifically represent the contraction of only the left atrium. The contraction of the atria occurs after depolarization, but the P wave represents depolarization, not contraction.

QRS complex represents ventricular contraction:

• This statement is correct. The QRS complex represents the depolarization of the ventricles, which leads to ventricular contraction.

T is the end of systole:

• This statement is correct. The T wave represents ventricular repolarization, which occurs towards the end of the systole (contraction phase of the heart).

P is the contraction of both atria:

• This statement is correct. As mentioned earlier, the P wave represents the depolarization of both atria, which leads to their contraction.

The incorrect statement is A.

The correct answer is (A) : P is the contraction of only left atria..